CN115900863A - A DN15 caliber through-beam type ultrasonic water meter transducer lead-out line and sealing structure - Google Patents

Abstract

The invention belongs to the technical field of flow metering equipment, and specifically relates to a DN15 caliber through-beam type ultrasonic water meter transducer lead-out line and a sealing structure, aiming to solve the existing technology that the through-beam type ultrasonic DN15 caliber water meter has excessive water flow gaps in the pipe. Small, low measurement range ratio due to the use of variable-diameter conversion joints, and the gap between the six principles of the optimal solution for the development of ultrasonic water meter technology, by changing and optimizing the structure and layout of the transducer, transducer and intermediate diversion The sealing method of the tube and the outer metal tube and the way of the lead-out line of the transducer can solve the problem of DN15 caliber in ensuring a large pitch and a large water flow gap in the meter, which is conducive to the passage of conventional impurities in the water, reduces the overall sealing parts, and facilitates the lead-out of the transducer signal line At the same time of operation, the structure is simple, safe and reliable, so that the present invention has the characteristics of maximizing the measurement range ratio, minimizing the starting flow rate, measuring high precision and batch production highly consistent.

Description

A DN15 caliber through-beam type ultrasonic water meter transducer lead-out line and sealing structure

technical field

The invention belongs to the technical field of flow metering equipment, and in particular relates to a lead-out line and a sealing structure of a DN15 caliber through-beam ultrasonic water meter transducer.

Background technique

In the era of big data of the Internet of Things, artificial intelligence and industrial self-control, it has become irreversible to gradually replace mechanical or electromechanical flowmeters with all-electronic flowmeters in the field of water, heat and gas supply metering for industry and people's livelihood. Trend.

According to the needs of actual applications, the fluid metering industry or occasion expects standard flow metering instruments that are compatible with various caliber specifications, low pressure drop, high precision, high reliability, no wear parts, durability and economy. At present, the most widely used electronic flowmeters in the world are electromagnetic flowmeters and the rising star ultrasonic flowmeters.

Ultrasonic flowmeter is accompanied by its time difference timing chip (from 2012 to 2017, AMS, D-FLOW, TI and other companies in the world have successively launched more advanced time difference timing chips. At present, its resolution has reached 5-10 ps, fully satisfying Water metering application requirements) technology breakthrough and rise. Compared with electromagnetic flowmeters, ultrasonic flowmeters are sampled through time-difference digital signals (electromagnetic flowmeters are sampled through analog signals). Taking the ultrasonic water meter as an example, it has outstanding technical advantages: smaller initial flow rate (such as liquid with a flow rate of 0.8 ~ 1mm/s), wider range ratio, and the ability to actively measure the time difference of the process with sound waves, which can be converted into fluid The flow rate and temperature are simultaneously compensated for the measured volume change (for this, the electromagnetic flowmeter needs to be equipped with a thermometer), and the measurement of large-caliber multi-channel has higher accuracy and safety (while the electromagnetic flowmeter only has a pair of coils and Corresponding electrode, if there is a fault, it will be scrapped), can measure various low-viscosity liquids (electromagnetic flowmeters cannot measure low-conductivity liquids, such as pure water), and can also measure/measure gases such as gas (electromagnetic flowmeters cannot Measuring gas flow).

Then, how to define the technical development direction and principles of the upgrading and improvement of ultrasonic water meters? Usually, the main performance indicators of flowmeters are measurement accuracy and range ratio, and the measurement accuracy is the ratio of flow measurement value of flowmeter to actual flow value. Stability and mass production consistency are important conditions for determining accuracy; the range ratio is the ratio of the common flow rate to the minimum flow rate under the guarantee of the flowmeter measurement accuracy, which reflects the range of accurate measurement and increases the distance between ultrasonic transducers. The effective distance is a necessary condition to improve the turndown ratio. Obviously, the higher the measurement accuracy and the larger the turndown ratio, the better the measurement performance of the flowmeter.

In recent years, the measurement industry has greatly improved the practical application of ultrasonic flowmeters. The composition of the ultrasonic flowmeter, in addition to the time difference integration circuit, also includes the transducer, the installation method of the transducer and the structure of the flow channel. comprehensive performance and quality. Taking ultrasonic water meters as an example, especially in accordance with the constraints of new water meter standards, the industry has clearly defined the direction of technological development, and its optimal solution should follow the following principles, which are summarized as follows:

(1) The principle of sound path maximization: In order to make the ultrasonic water meter have a large range ratio, for ultrasonic water meters, especially the most commonly used DN15 caliber, the sound path maximization mode between ultrasonic transducers should be adopted. Because for water meters, the large range ratio is an extremely important indicator for trade settlement, and it is also the most important technical indicator of water meters, which is completely different from industrial flow meters. To make the ultrasonic water meter have a large range ratio, the projection distance of the distance between the two transducers of the ultrasonic water meter in the direction of the water flow in the main pipe should be maximized to obtain a larger range ratio and a smaller starting flow, ( For water meters, the national standard raised the maximum range ratio or flow ratio to R=1000 in 2018).

In this regard, through theoretical analysis, conclusions can be drawn about the measurement quality of ultrasonic flowmeters:

In the field of water metering, the turndown ratio defined as ,in, It is a given value corresponding to the common flow rate under a certain pipe diameter; The minimum flow rate required to meet a certain measurement accuracy (for example, the measurement accuracy of the secondary flowmeter is ±5%).

After in-depth analysis and derivation in the following article, an important conclusion is drawn: for the fluid passing through the flowmeter pipeline, the measured initial flow rate (that is, the minimum flow rate that the flowmeter can sense and measure) The lower (corresponding to its flow rate the lower the It is related to the time difference chip resolution of the ultrasonic flowmeter and the pipeline structure of the flowmeter), corresponding to this, is also proportional to the corresponding strain lower (i.e. the minimum flow rate corresponding to becomes lower). Usually, in practical applications, its empirical value is ( Depending on the overall zero drift produced by the ultrasonic flowmeter circuit and transducer and the water resistance design of the flowmeter pipeline, it will vary). From this, it can be derived that under a certain caliber (flowing through the flowmeter pipeline and time intervals used are equal), turndown ratio Distance from two transducers The relationship between is:

In the above formula, is the usual flow rate of a certain caliber flowmeter, for with The flow rate of the fluid in the corresponding flowmeter pipeline, In order to meet the minimum flow rate required by a certain measurement accuracy, for with The flow rate of the fluid in the corresponding flowmeter pipeline, for a certain caliber flowmeter, and is a constant (selected value), is the circumference ratio, is the inner radius of the flowmeter pipe, For measuring time, is the distance between the opposing surfaces of the two transducers in the pipeline of the ultrasonic flowmeter, is the angle between the two transducers in the flow direction of the flowmeter pipeline ( is an acute angle, when When the two transducers are connected in the same direction as the water flow, , is a known quantity related to the measurement time difference and sound velocity of the flowmeter, is the known quantity related to the measurement time difference and sound velocity of the flowmeter, let = , is a constant, and Calculated by the difference formula of ultrasonic flowmeter draw, namely , thus, in specific calculation, according to substitute. from above The following relationship can be drawn:

Increase the projection distance between the two transducers in the flow direction of the flowmeter pipeline , can effectively improve the turndown ratio of the flowmeter .

(2) The principle of the opposite-beam installation between a pair of transducers: the acoustic signals of the opposite-beam installation are directly sent and received by a pair of transducers, so the amplitude of the effective signal is the highest. Because the reflective type has one or several reflective surfaces, there will be energy loss in the transmission of sound wave reflection (when the reflective surface is large enough, the ideal sound energy loss is 10-20%, which generally does not affect the measurement), especially when the reflective surface has an angular deviation Or fouling after use, the energy loss can reach 40-60%, which will seriously affect the normal measurement. In addition, there is a reflective surface, and its installation structure is complex, especially if the water resistance distribution of the reflective surface is not handled properly, it will also affect the measurement accuracy.

(3) The principle of consistency; the flow channel forming and processing technology of the base meter of the ultrasonic water meter have high component installation accuracy and consistency requirements, which determine the mass production quality of the flowmeter. In particular, it is necessary to ensure that the distance between the emitting surfaces of the two transducers is fixed, and it is not affected by the difference caused by the processing of the pipe section and the installation of the transducer. The tedious workload of man-made error correction for its individual.

(4) Safety principle of pipe body sealing: In the case of liner pipes, in order to ensure the safety of sealing, partial sealing rather than overall sealing should be adopted as much as possible to ensure the reliability and durability of the sealing.

(5) Adaptability principle: small-bore flowmeters are convenient for installing temperature sensors to meet the needs of heat supply measurement;

(6) The principle of simple structure and convenient assembly: the ultrasonic water meter has a simplified structure and unique certainty in installation, so that it is easy to assemble as a whole, that is, it is stable and reliable, and has high consistency.

According to the above six principles, for small-caliber ultrasonic water meters, especially the most common civilian DN15 caliber, the most effective way is the built-in through-beam transducer structure and the direct application of the overall pipe section to process and manufacture it into a base meter for DN15 flowmeters. .

According to the principle of sound path maximization, to obtain better performance (small initial flow and a large turndown ratio R), a pair of small-diameter transducers in the through-beam mode must be placed in the pipe under the condition that the DN15 straight pipe remains unchanged, and a larger transducer spacing should be obtained as much as possible; in addition, Compatibility with water treatment and water quality conditions in different regions should be considered. According to experience, the diameter of impurities in tap water is less than 3mm. Corresponding to the ultrasonic flowmeter, a low water resistance filter needs to be installed at the front of the meter. Due to the small area, according to the application experience before the ordinary single flow rate mechanical meter, the mesh diameter needs to reach Φ2.5~3mm to ensure that it is not easy to block. Therefore, under normal circumstances, for all electronic meters, it is best to ensure that the minimum water flow inside the base meter of the flowmeter passes through the gap ≥ 3mm. In this way, the function of the filter screen is only to remove foreign matter such as individual hairs, and allow small particles of impurities to pass through, ensuring that the filter screen can be used for a long time without clogging. In addition, a series of problems such as the simple and safe system sealing method of the flowmeter and the easy-to-operate transducer lead-out structure (the lead-out line cannot be soaked in water) must be solved. So far, the realization of the above issues still lacks safe and effective solutions.

Compared with the standards of the above principles, there are still defects or deficiencies in the prior art.

Patent Authorization Announcement No. CN 201503288 U provides a base meter for ultrasonic straight-through beam flowmeter. It can be seen from the figure that the patent uses a large transducer (1MHz transducer, conventional convex size front Φ17, rear End Φ21), the installation and fixing of the transducer takes up a lot of space. The expansion of the space volume makes the pipeline have to be enlarged and assembled after segmental processing. This structure is not only complicated, labor-intensive to install, but also requires multi-stage sealing, which has poor reliability. Since the pipeline is assembled with nuts in sections, this will cause deformation and deviation of the device, which directly affects the batch consistency of the flowmeter. In addition, the large transducer produces a large water resistance in the flow channel, and the flow around it will directly affect the accuracy of flow measurement at different flow rates. In addition, the sealing of the lead-out wires of the transducers is not described in detail in the patent.

Patent authorization announcement number CN 201716054 U provides another transducer directing mode, in which the transducer extends from the side of the pipe. The opposite-beam ultrasonic flowmeter requires that the two opposing surfaces of the transducer must be strictly parallel, and the transducer is fixed by a single hole extending in and without support below, and the convex edge of the transducer is pressed to seal the bottom as shown in the figure. The way of the ring, that is, sealing and positioning, is extremely unreliable. The lower part of the transducer is suspended in the water channel. When impacted by strong water flow, under the action of lever torque, there will be uneven pressure on the sealing surface and a slight inclination (the compression amount of the sealing ring is regulated and cannot be too tight, so it is generally not possible to use this The surface is the positioning surface), and there is a risk that the opposing surfaces of the two transducers will be difficult to keep parallel. Experiments have shown that for plane waves, the sound energy loss caused by the non-parallel surfaces of the two transducers is fatal, and this method also has the problem of the durability of a single sealing ring.

The patent authorization announcement number CN 211317425 U proposes a small-diameter through-beam straight-through ultrasonic flowmeter, which has better stability in the through-beam mode. However, the standard pipe length of DN15 is specified as 165mm. If this mode is applied to the DN15 caliber, according to the sealing and lead-out method described in the patent, it is determined that a structure with a larger diameter of the middle pipe section must be used to place the opposite beam. Mode transducer to ensure the minimum gap ≥ 3mm. The two ends of the pipe will be connected with variable diameters as described in the patent authorization announcement number CN 208223575 U to reach the DN15 specification. This threaded reducing head method has a shorter sound path and a lower range than R, and the distance between the two transducers is not fully opened, which is contrary to the principle of maximizing the sound path.

Further analysis on the patent authorization announcement number CN 211317425 U shows that the ultrasonic water meter (flow meter) is composed of three parts: time difference circuit system, transducer, transducer installation mode and pipeline structure. At present, the time difference circuit system is mainly provided by AMS, D-Flow, and TI, and its accuracy has met the application requirements of water meters. Therefore, to improve the performance and quality of the water meter, it is mainly determined by the transducer and its shape and structure, the combination of the transducer and the pipeline, and the installation structure in the pipeline.

For the specifications of the ceramic vibrator, the core component of the ultrasonic transducer, the Water Meter Committee of the China Metrology Association defines the transducer application standards as follows:

It is stipulated that the vibration frequency of the transducer ceramic plate can be: 1MHz, 2MHz, 4MHz,

The ratio of common diameter and thickness of ceramic sheet is: Φ12/2mm; Φ8/1mm; Φ8/0.5mm;

The wavelength corresponding to each frequency of the material is: 2.5mm 1.25mm 0.625mm

(Assume that the sound velocity of a sound-conducting material at room temperature is 2500m/s)

Conventionally, the larger the size of the transducer, the greater the intensity of the sound wave, but the larger the installation size; the higher the frequency of the transducer, the shorter the wavelength, the smaller its physical diameter and volume, which is easy to install, and its circuit The higher the accuracy of the timing trigger, the more accurate the time difference calculation. The manufacturing level of early transducers was low, and the reflective type had sound wave loss, so most manufacturers used larger volume 1MHz transducers (using Φ12-14mm ceramic chips). In recent years, with the improvement of precision manufacturing level, the electric/acoustic conversion efficiency of small-sized, high-frequency transducers has been greatly improved, which has fully met the application requirements. Especially for the ultrasonic small-caliber through-beam mode, you can choose a transducer with a smaller size (Φ8mm ceramic chip) and a frequency of 2MHz or 4MHz. Then, with the 1mm thickness required for the package plastic case, the minimum diameter of the transducer can be Φ10mm.

Once the frequency and size of the transducer are determined, the shape of the transducer, its combination with the pipeline, and its installation structure in the pipeline become the key to determining performance.

The patent authorization announcement number CN 211317425 U is a built-in solution for transducers that can ensure the maximum distance between two transducers. It can be better applied to DN20 and above calibers. However, usually, for a DN15 water meter flowmeter, if the transducer is to be built in, it is also necessary to ensure that the minimum gap of the water flow at the position of the transducer in the pipe is ≥ 3mm, so as to ensure the smooth passage of impurities in the water.

According to the implementation analysis of this patent, if it is applied to a DN15 caliber water meter, a built-in transducer is used, and the transducer is the inner tube of the flowmeter (which becomes one body). The two ends of the transducer are fixed by metal pressure rings and sealing rings with built-in outer wires. With the seal, the transducer lead-out line is drawn out from the middle of the tube, then the minimum gap for water flow can be calculated:

The outer diameter of DN15 flowmeter pipe thread is 26.44mm (standard). In order to process the internal thread, its safe thickness is at least 3.2mm (the height of the outer thread is about 1.2mm, the height of the inner thread is 1mm, and the remaining wall thickness is about 1mm); The minimum diameter is Φ10mm (8mm ceramic resonator plate + 1mm protective shell on one side); inside the tube, the thickness of the outer tube of the transducer bracket that is in contact with the metal pressure ring with outer wires is at least 2.5mm (side sealing ring 1.5 ~ 2mm, replace The smaller diameter Φ1.5mm of the lead-out line of the double-strand shielding belt jacket of the energy device, there is a groove on the outside of the inner tube, the depth must be 1.5mm, and the remaining wall thickness of the plastic groove is 1mm);

Then, it can be calculated that the flow gap at the transducer where the fluid flows through the tube is:

(26.44mm-2×3.2mm-2×2.5mm-10mm)/2=5.04mm/2=2.52mm≤3mm.

Therefore, for the DN15 caliber, the built-in transducer is fixed and sealed by the metal pressure rings at both ends of the tube, which cannot ensure the safe passage of impurities in the water flow and is easy to block. The middle tube with a thicker caliber must be used, and the two ends are converted with DN20-DN15 adapters. Promptly by patent announcement number CN 208223575 U that way. At this time, the distance between the emitting surfaces of the two transducers is about L=63mm, so this mode violates the principle of maximizing the sound path, and the range ratio R of the water meter is greatly reduced.

From the above analysis, it can be seen that the main reason why the scheme of the patent authorization announcement number CN 211317425 U cannot be directly applied to the DN15 caliber is that the transducers are placed at both ends of the straight pipe of equal diameter, in order to lead out the signal line from the middle of the pipe and its sealing needs , while using metal pressure rings at both ends of the tube to seal the liner as a whole. Due to the placement of the sealing ring and the wiring outside the liner, the thickness of the outer ring of the liner needs to be thickened, resulting in water flow in the tube. The gap is too narrow; in addition, this mode uses internal pressure rings with external wires at both ends of the pipe, which is labor-intensive and inefficient to assemble; and due to the existence of internal threads in the external pipe, the sealing method of extruding and installing the sealing ring at both ends is also safe. Hidden danger (easy to scratch); In addition, the inner liner is sealed as a whole. In view of the waterproof requirements, it is not convenient to install a plug-in temperature sensor; especially, the inner space between the inner tube and the metal outer tube is narrow. The lead wires of the two transducers should be routed along the outer groove of the inner tube, and both lead out from the middle hole of the tube (the longer parts of the lead wires at both ends pass through the tube, and there is no room for placement and operation of the redundant wire ends. ) is quite difficult, and the assembly is labor-intensive and time-consuming.

To sum up, for the DN15 caliber ultrasonic water meter, which can meet the above six principles as much as possible and has a safe sealing and convenient lead-out solution, judging from the currently published patents, there is still a lack of effective solutions.

Contents of the invention

In view of the deficiencies in the prior art, the present invention intends to change the structure of the transducer, the sealing method of the transducer and the intermediate guide pipe and the outer metal pipe, the way of the lead-out line of the transducer, the water meter integration circuit box and the flowmeter. The fixed installation method of the base meter can solve the problem of DN15 caliber under the premise of ensuring a large pitch and a large water flow gap, reduce the overall sealing parts, facilitate the lead-out operation of the transducer signal line, and achieve a simple structure, safety and reliability.

It can be seen that for an ultrasonic water meter with a length of 165mm and a DN15 caliber, if it can be realized as shown in Figure 1, while installing the through-beam mode transducer, ensure that the minimum water flow gap is ≥ 3mm, and place the transducer in the metal tube as much as possible. In this way, it can be calculated that the distance between the emitting surfaces of the transducer is about 113mm, and the distance between the two emitting surfaces will be much larger than the 63mm when there is an adapter. (here , ), it can be seen that after the improvement, the range ratio is increased by 113/63=179.3%, reaching a qualitative leap. Coupled with the appropriate diameter reduction in the middle of the flowmeter (under the premise of meeting the pressure loss requirements), it can further effectively improve the range ratio of the DN15 water meter, the stability of the flow rate and reduce the starting flow rate of the water meter (the actual test of this scheme can be achieve starting flow <0.4L/h).

The invention provides a lead-out line and sealing structure of a DN15 caliber through-beam ultrasonic water meter transducer. A fixed seat for the lead wire of the transducer and a fixed seat for the temperature sensor; a special-shaped transducer is installed at both ends of the straight-through tube, and the two transducers and the reduced-diameter rectifier tube in the middle are connected by laser welding to form a pair of opposite beams. The overall structure of the type transducer lining. There is only a partial seal between this integral lining structure and the inner side of the metal straight pipe with equal outer diameter, and there is no overall seal, which provides the possibility to increase the minimum water passage gap in the pipe. Therefore, under a given length of the straight-through pipe of the ultrasonic water meter, for the most widely used household DN15 caliber, the minimum water passage gap in the flow channel can be greater than 3mm, which can avoid the cumbersome large-diameter-to-small-diameter conversion joint for DN15 caliber. Therefore, not only can a stable maximum distance (sound path) be obtained between the emitting surfaces of the two transducers, but also it is easy to assemble and lead out the signal lines of the transducers.

The invention is a DN15 caliber through-beam type ultrasonic water meter transducer lead-out line and sealing structure, which is characterized in that it includes an equal-diameter metal outer pipe and three kinds of external thread forming structures, a special-shaped transducer, a rectifier tube, and a transducer The fixed seat of the lead wire of the transducer, the fixed head of the lead wire of the transducer, the circuit box of the water meter, the fixed cap of the lead wire, and the fixed seat of the temperature sensor; diameter metal outer tube; the special-shaped transducer is composed of a special-shaped transducer structure and a transducer guide cover; the two transducer structures are connected by a reduced-diameter rectifier tube to form a pair of opposite-beam transducers The structure of the inner tube body of the transducer; under the synergy of the structure of the special-shaped transducer, the transducer lead-out line and the sealing method, the two ends of the inner side of the equal-diameter metal outer pipe can be placed and fixed without using a pressure ring. In order to realize the minimum water clearance in the flow channel of the water meter flowmeter is greater than 3mm, avoiding the disadvantages of the existing DN15 caliber transducer installed in the opposite direction, and its pipe body interface has to use cumbersome large-diameter to small-diameter conversion joints , thus, a stable and maximized distance (sound path) is obtained between the two transducer emitting surfaces, and the components are easy to assemble; in the center structure of the equal-diameter metal outer tube, the transducer lead-out wire fixing seat, the transducer The DN15 caliber through-beam ultrasonic water meter is composed of the fixed head of the lead wire, the circuit box of the water meter instrument, the fixed cap of the lead wire and the temperature sensor, which realizes the maximization of the measuring range ratio and the minimization of the starting flow value.

The middle part of the special-shaped transducer structure in the present invention is equipped with a transducer ceramic sheet assembly; the middle part of the special-shaped transducer structure and the inner side of the outer ring are respectively connected by an upper support column and a lower support column; the transducer The positioning fixing bolt is installed in the lower supporting column; the positioning fixing bolt is positioned by the positioning blind hole; the inner hole of the upper supporting column is a lead line oblique hole, one end of which communicates with the inside of the transducer, and the other end leads out of the transducer The central through hole of the line fixing head is connected, and the signal lead-out line of the transducer is drawn out from the center of the transducer through the inclined hole of the lead-out line and the center hole of the lead-out line fixing head to the PCB of the integration circuit.

The function of the slanted hole for the lead-out line of the transducer in the middle of the upper support column is: although the fixing seat of the lead-out line of the transducer is located on the inner side of the pipe thread at both ends of the equal-diameter metal outer tube, since the lead-out line can be drawn out through the slanted hole for the lead-out line Therefore, the special-shaped transducer structure should be installed as close as possible to the inner sides of both ends of the equal-diameter metal outer tube without considering the influence of the positional dislocation caused by the transducer lead-out wire fixing seat being located on the inner side of the pipe thread. Therefore, it can be installed as much as possible It is possible to effectively increase the distance between the emitting surfaces of the two transducers, that is, to increase the sound path and increase the range ratio R.

Since the gap of the transducer in the middle part of the special-shaped transducer structure and the cross-sectional area through which the fluid passes are the smallest, the middle part of the special-shaped transducer structure described in this application is connected with the inner side of the outer ring by two support columns, and the upper and lower support columns are used. Instead of using multiple, its purpose is to reduce blocking, increase cross-sectional area of water, and reduce pressure loss.

The transducer lead wire fixing seat is located on the outside of the equal-diameter metal outer tube of the flowmeter base meter and the inner side of the outer metal pipe thread; the transducer lead-out wire fixing seat and the equal-diameter metal outer tube are connected by laser welding; The fixed head of the transducer lead wire is located at the lower end inside the transducer lead wire fixing seat, and the sealing ring on the side is sealed with the inner side of the transducer lead wire fixing seat, and the height positioning is carried out by the positioning table in the lead wire fixing seat. In order to ensure the height and flatness of the fixed head of the lead wire, it not only ensures that the sealing ring at the lower part of the fixed head of the lead wire has a reasonable amount of compression, but also embeds the lower part of the fixed head of the lead wire into the structural part of the special-shaped transducer to achieve positioning And the role of fixing the structure of special-shaped transducers. That is, further, the sealing ring under the lead wire fixing head is used for sealing the transducer structure; the side seal ring is used for sealing the inner side of the lead wire fixing seat.

The elastic washer is located above the lead wire fixing head and below the lead wire fixing nut, and the lead wire fixing nut compresses and fixes the transducer lead wire fixing head by applying force to the elastic washer.

The connection between the reduced-diameter rectifier tube and the transducer structural parts at both ends is completed by gluing or laser welding at the seam (laser welding has been widely used in metal and plastic welding at present), forming The overall structure of a pair of through-beam transducers is lined with a tube body. The sealing ring 441 on the necking rectifying tube 44 plays the role of fixing the rectifying tube and blocking water with the inner wall of the metal tube during installation, and does not play an integral sealing role.

The overall structure of the lining tube body of the double-beam type transducer, as shown in Figure 1, is fixed by the lead wire fixing head from the upper part of the casing, and the positioning fixing bolt is positioned from the lower part of the tubular transducer, Very strong. The fixing bolt is located in the lower support column of the transducer. Further, the fixing bolt is composed of an outer wire nut, a fixing bolt rod and a spring, and the inner hole of the outer wire nut is a hexagonal hole, which is convenient for installation. Its positioning is completed by snapping the fixed bolt rod into the corresponding blind hole inside the equal-diameter metal outer tube. Installation of the fixing bolt: Insert the fixing bolt assembly, spring, and fixing bolt rod into the blind hole of the lower support column of the special-shaped transducer structure, and tighten the outer thread nut of the fixing bolt to cooperate with the inner thread of the blind hole of the lower support column.

The length of the overall structure of the inner liner body of the pair of opposite-beam transducers is 0.3 mm less than that of the metal outer tube with equal diameter on one side. It is mainly accepted by the metal nozzle of the butt joint, which can effectively protect the lining pipe and make it less stressed and not deformed during long-term use.

The installation of inserting the overall structure of the lining tube body of the through-beam transducer into the metal outer tube of equal diameter: press the fixing bolt rod, and insert one end of the transducer sleeve into the inside of the metal outer tube. The positions of the holes are staggered, that is, do not let the fixed bolt rod on one side enter the blind hole. After pressing the other end of the fixed bolt rod and inserting all the transducer sleeves into the metal outer tube, use a tool to clamp the two transducers. The transducer support column is rotated so that the two fixing bolts at both ends enter their respective blind holes at the same time to complete the installation and fixation.

The two ends of the equal-diameter metal outer pipe have pipe threaded joints, and the threaded joints have three forming methods, one of which is that the wall thickness can meet the requirements of the equal-diameter metal outer pipe on the outer pipe to directly car out the pipe threaded joint; The second is that when choosing a thinner metal outer tube with equal diameter, put on the processed casing with external thread, and fix it with the equal diameter metal outer tube by laser welding; the third is, when choosing a moderate thickness When the metal outer tube of equal diameter is used, the part of the wall thickness is removed by car, just put on the processed casing with external thread, and the two are fixed by laser welding.

For the selection of the above-mentioned first forming method, as shown in accompanying drawing 2, that is, the thickness of the wall can satisfy the metal outer pipe of equal diameter that can be directly driven out of the pipe thread joint on the outer pipe. Although the metal outer pipe is slightly thicker in this forming method, But the advantage is that it is easy to process, and it can meet the technical requirements that the minimum gap in the special-shaped transducer is greater than 3mm, that is, the smooth passage of impurities. This is because the two ends of the pipe of the present application do not need to use metal pressure rings with outer wires, and the lead-out wires of the transducer do not pass through the inner shell. The tooth height is about 1.2mm), the outer tube of the transducer does not need to be provided with grooves, and the lead-out line of the transducer is guided to the outlet in the middle of the tube, so the outer tube thickness of 1.8mm fully meets the strength requirements. Then, after the structure of the DN15 caliber outer tube is improved, the minimum gap between the equal-diameter metal outer tube and the special-shaped transducer can be calculated as:

(26.44mm-2×2.5mm-2×1.8mm-10mm)/2=7.84mm/2=3.92mm>3mm, compared with the patent announcement number CN 208223575 U, it not only saves materials, but also fully meets the requirements for the smooth passage of impurities ;

For the above-mentioned second formation method, as shown in Figure 3, in order to save consumables, choose a metal outer tube with a thinner wall thickness, such as the outer tube wall thickness is 1.0mm (in line with domestic water thin-walled stainless steel pipe standard CJ/T 151 -2016), which is different from the first method above, which is to directly form the outer metal threaded section at both ends of the metal outer tube. The threaded section uses a threaded casing and welds the metal outer tube with the same diameter by laser. In this case, the wall thickness of the equal-diameter metal outer tube is 1.0 mm, instead of 2.5 mm in the first forming method. Then, the outer diameter of the thread is still 26.44mm, the threaded sleeve has a length of 11mm, a thickness of 2.0mm (wherein, the thread height is 1.2mm), and an inner diameter of 22.44mm, and the wall thickness of the equal-diameter metal outer pipe is 1.0mm, with an outer diameter of 22.44mm. Put a casing with a length of 11mm and a thickness of 2.0mm with external threads on both ends of the outer metal pipe with a wall thickness of 1mm, and weld the threaded casing and the metal outer pipe with equal diameters at the seams to form a whole , so the minimum gap between the inner side of the equal-diameter metal outer tube and the special-shaped transducer is calculated as:

(26.44mm-2×3mm-2×1.8mm-10mm)/2=6.84mm/2=3.42mm>3mm. Can meet the requirements of smooth passage of impurities. The formation method of this external thread meets the application strength of the metal shell of the DN15 flow base meter, and at the same time, compared with the patent announcement number CN 208223575 U and the first formation method above, it is necessary to save the material of the outer pipe;

For the above-mentioned third formation method, as shown in Figure 4, when choosing a metal outer tube with a moderate thickness and equal diameter, if it is necessary to increase the strength, for example, choose a wall thickness of 1.5mm. The outer diameter of the thread remains unchanged at 26.44mm, the threaded casing has a length of 11mm, a thickness of 2.0mm (among them, the thread height is 1.2mm), an inner diameter of 22.44mm, and the wall thickness of the equal-diameter metal outer pipe is 1.5mm , the diameter of both ends is 0.25mm, the length is 11mm, and the length is 11mm, the thickness is 2.0mm. The first forming method is to weld the threaded sleeve and the metal outer tube with 0.25mm of unilateral car removal at the end seam by laser to form a whole. The minimum gap in between is:

(26.44mm-2×3mm-2×1.8mm-10mm)/2=6.84mm/2=3.42mm>3mm. The result is consistent with the second formation method, and also satisfies the smooth passage of impurities. Therefore, for the case where the wall thickness of the equal-diameter metal outer tube is greater than 1.5 mm, the implementation of this forming method can be continued. Compared with the patent notification number CN 208223575 U and the first forming method above, this forming method saves the outer tube material.

For the above-mentioned second and third methods of forming the external thread of the thin tube equal-diameter metal pipe, as shown in Figures 3 and 4, two transducer structures are connected with the reduced-diameter rectifier tube to form a pair of opposite-beam transducers. The overall structure of the lining pipe of the energy generator, its positioning and fixing methods are as follows: the middle part of the necked rectifying pipe is sealed and fixed in the blind hole in the middle of the rectifying pipe through the bolts and sealing rings in the rectifying pipe fixing seat; The first lead wire fixing head is pressed and fixed from the upper part of the casing, so three positioning and fixing places are formed for the overall structure of the lining pipe body, which is very firm.

The ceramic sheet assembly of the transducer is characterized in that the ceramic sheet assembly is placed in the blind hole of the special-shaped transducer structure, and the ceramic sheet is bonded to the bottom of the blind hole through two-component A and B glue, The positive and negative electrodes of the ceramic sheet are welded on the PCB, and the lead wires are also welded on the PCB.

Described transducer lead-out line has two kinds of modes: one is, as shown in accompanying drawing 1, after encapsulating in the blind hole of special-shaped transducer structural part, after installing ceramic sheet, PCB, welding lead-out line, at this moment Do not install the rectifying cover first, but insert the integral inner lining sleeve into the metal pipe, insert the two fixing bolts into the respective blind holes of the metal inner pipe, and fix the integral inner lining sleeve. After that, pass the lead-out wire of the transducer through the lead-out inclined hole, and pass through the lead-out wire fixing seat. Afterwards, the rectifying cover can be buckled, and the assembly and extraction of the transducer and the lead-out wires in the equal-diameter metal outer tube are completed. In order to achieve IP68 waterproof, use a flat-head thin tube to inject two-component A and B glue waterproof curing glue into the transducer from the lead-out wire fixing seat through the lead-out oblique hole, so that the structural parts of the special-shaped transducer and the replacement The energy deflector cover is tightly integrated as a whole.

The second is that, as shown in accompanying drawing 2, the lead-out line of the transducer is docked with the internal connection socket and the external connection plug, and is drawn out from the lead-out line fixing socket: the socket is fixed in the socket fixing hole, and the socket The bottom of the ceramic plate is welded to the positive and negative electrodes of the ceramic sheet on the PCB through a wire. Therefore, before the overall lining sleeve of the transducer is inserted into the metal pipe, the two-component A and B glue waterproof curing glue can be injected into the interior of the transducer, and then the rectifying cover is fastened to make the structural parts of the special-shaped transducer It is tightly integrated with the transducer deflector cover.

The meter circuit box of the water meter is located outside the equal-diameter metal outer tube of the flowmeter base meter, and is composed of a lower case of the meter circuit box and an upper case of the meter circuit box. The integrated circuit board, instrument display screen and battery are located in the instrument circuit box. The lower shell of the instrument circuit box is cylindrically matched with the outer ring of the transducer lead wire fixing seat, and there is a sealing ring between the two. The lead wire fixing nut has two functions: one, it compresses the transducer lead wire fixing head by applying force to the elastic washer; and the other function is to compress the lower shell of the circuit meter box, so that The fixing of the bottom case of the circuit meter box is completed by using a very simple method, saving fixing devices. According to actual needs, waterproof glue can be filled in the circuit box of the circuit meter to make it reach the IP68 protection level.

In the present invention, if the heat energy carried by the fluid is to be measured, a temperature sensor needs to be installed additionally. Since there is no need for a waterproof seal between the liner integral sleeve composed of the special-shaped transducer and the rectifier tube and the inner side of the metal outer tube, when performing heat metering applications, a temperature sensor mounting seat can be placed near the outer end of the metal outer tube near the water outlet , the temperature sensor can be conveniently installed in the temperature sensor mounting seat, as shown in Figure 8, the temperature measuring rod of the temperature sensor is obliquely inserted outside the diversion cover of the transducer at the water outlet, which does not affect the measurement of the fluid.

To sum up, compared with the prior art, the present invention has outstanding substantive features and significant progress, specifically manifested as:

First, for a DN15 caliber or a small caliber ultrasonic flowmeter base meter of a given length, the present invention achieves the ability to combine two built-in special-shaped transducer structures The parts are placed close to the inner sides of the equal-diameter metal straight pipe, and there is no need to connect the flowmeter straight-through pipe. The large-to-small joint conversion thread method is used to reduce the diameter connection, and the minimum water flow gap in the DN15 caliber straight-through pipe can be guaranteed to be greater than 3mm, which is beneficial. Impurities pass through safely. In this way, the distance between the emitting surfaces of the two transducers is maximized, that is, the sound path is maximized, so that the DN15 caliber or small caliber ultrasonic flowmeter realizes the maximum turndown ratio and the minimum starting flow rate.

Second, the effect of the inclined hole structure of the transducer lead-out line in the middle of the support column on the special-shaped transducer structure is: although the transducer lead-out line fixing seat is located on the inner side of the pipe thread at both ends of the equal-diameter metal outer tube, Since the lead-out wire can be drawn out through the lead-out inclined hole, the special-shaped transducer structure can be installed as close as possible to the inner sides of both ends of the equal-diameter metal outer tube without considering the position caused by the transducer lead-out wire fixing seat being located on the inner side of the pipe thread Therefore, it is possible to effectively increase the distance between the emitting surfaces of the two transducers as much as possible, that is, to increase the sound path and increase the range ratio R.

Third, since the gap and the cross-sectional area of the fluid passage in the middle part of the special-shaped transducer structure are the smallest, the middle part and the inner side of the outer ring of the special-shaped transducer structure in the present invention adopt two support columns, the upper and the lower. Connection, rather than using multiple, its purpose is to reduce obstruction, increase cross-sectional area of water, and reduce pressure loss.

Fourth, the socket and plug type transducer lead wire and sealing structure of the present invention skillfully realize the signal connection between the transducer lead wire and the flowmeter integrated circuit board through the internal and external docking mode of the external connection plug and the internal connection socket. Pass the plug. This method not only removes the overall sealing method of the inner liner, but also facilitates the installation of the transducer and the extraction of the signal line of the transducer.

Fifth, the direct lead-out line and the sealing structure of the back-encapsulated transducer cover of the present invention do not adopt the overall sealing method for the inner liner, and under the condition of ensuring the minimum water gap, it also realizes less components and is convenient to replace. The signal wire of the energy generator is drawn out and sent to the signal transmission of the flowmeter integrated circuit board.

Sixth, the fixed head of the lead wire of the transducer according to the present invention is positioned in height through the positioning platform in the lead wire fixing seat, which ensures that the sealing ring at the lower end of the lead wire fixed head has a reasonable amount of compression, and can fix the lead wire The lower part of the head is embedded in the structure of the special-shaped transducer to play the role of positioning and fixing the structure of the special-shaped transducer.

Seventh, the thickness of the equal-diameter metal outer pipe and the pipe thread joints at the two ends of the outer side of the present invention have three forming methods. Notification number CN208223575 U is thicker equal diameter metal outer pipe, and material cost reduces.

Eighth, in the present invention, for the external thread forming method using equal-diameter metal thick tubes, for the overall structure of the inner tube body of the double-beam transducer, two lead-out wire fixing heads are used from the sleeve The upper part of the tube is pressed and fixed, and the two positioning and fixing bolts are positioned from the lower part of the tubular transducer, which is very firm.

Ninthly, in the present invention, for the external thread forming method using thin metal tubes with equal diameters, the overall structure of a pair of opposite-beam transducer inner liner tubes is formed by connecting two transducer structural parts with a reduced-diameter rectifier tube , the way of positioning and fixing is as follows: the middle part of the necked rectifying tube is sealed and fixed by the bolts and sealing rings in the rectifying tube fixing seat; the two ends are pressed and fixed from the upper part of the casing by two lead wire fixing heads, so, For the overall structure of the lining pipe body, three positions are positioned and fixed, which is very firm.

Tenth, the lead wire fixing nut of the present invention realizes the function of one generation and two. It compresses the transducer lead wire fixing head by applying force to the elastic washer; at the same time, another function is to compress and fix the circuit The lower shell of the meter box reduces the number of fixing devices for the lower shell.

Eleventh, the connection between the necked rectifier tube of the present invention and the transducer structural parts at both ends is completed by gluing or laser welding at the seam, forming a pair of opposite-beam transducers The overall structure of the liner tube body of the device, the purpose of this structure is to ensure that the distance between the emitting surfaces of the two transducers is consistent during mass production and remains constant during flowmeter assembly or use. The distance between the emitting surfaces of the transducer determines the range ratio, so this ensures the consistency of the parameters of the flowmeter and greatly facilitates the detection and calibration of the flowmeter.

Twelfth, the length of the overall structure of the lining pipe body of a pair of opposite beam transducers described in the present invention is 0.3mm less than that of the metal outer pipe with equal diameter on one side, and its function is to connect with the outer pipeline and install the flowmeter joint During the process, the extrusion force on the sealing rubber pad is mainly received by the metal nozzle of the butt joint, which can effectively protect the inner liner and make it less stressed and not deformed during long-term use.

Thirteenth, the lead-out line and sealing structure of the DN15 caliber through-beam ultrasonic water meter transducer described in the present invention, due to the change of the internal sealing structure, its straight-through pipe structure is convenient for laser welding at the outer end of the outer metal pipe water outlet The temperature sensor fixing seat is used to install the temperature sensor, which is convenient for heat energy measurement.

Fourteenth, the lead-out line and sealing structure of the DN15 caliber through-beam ultrasonic water meter transducer described in the present invention, the two lead-out line fixing seats provided by it are respectively located at the two ends of the metal outer pipe of equal diameter, which is the flow tube Setting and installing the flow control valve in the middle provides possibility and convenience.

Several external thread formation structures of metal straight pipes with equal outer diameters proposed in this application, special-shaped transducers and their sealing structures, positioning and fixing of special-shaped transducers through the transducer lead-out wire fixing head and the seal structure of the lead-out wires, The gluing or laser welding of the special-shaped transducer and the reduced-diameter rectifier into one, and the connection structure between the lower case of the integrated circuit box and the flowmeter base meter are all proposed through years of theoretical research and engineering research practice, and have been tested by practice. Validated, novel, inventive and practical.

Description of drawings

Figure 1 is a schematic diagram of the direct lead-out line and sealing structure of a DN15 caliber through-beam ultrasonic water meter transducer;

Figure 2 is a schematic diagram of the lead-out wire structure of a DN15 caliber through-beam type ultrasonic water meter connector;

Fig. 3 is a structural schematic diagram of a welded threaded casing of an equal-diameter thin-walled metal outer pipe;

Fig. 4 is a structural schematic diagram of a welded threaded casing of a metal outer pipe of equal diameter and moderate thickness;

Figure 5 is an exploded view of the plug-in lead wire structure of the special-shaped transducer;

Figure 6 is a side view of the water meter and a structural schematic diagram of the support column inside the special-shaped transducer;

Figure 7 is a schematic diagram of the position of the mounting seat of a DN15 caliber through-beam ultrasonic water meter temperature sensor;

Figure 8 is a schematic diagram of the installation position of the temperature measuring rod of a DN15 caliber straight-through ultrasonic water meter temperature sensor;

In the picture:

11. Equal-diameter metal outer pipe; 111. External thread; 112. External thread pipe; 22. Transducer lead wire fixing seat; 221. Sealing ring; 233. Positioning platform; 23. Transducer lead wire fixing head; 231 .Lower sealing ring; 232. Side sealing ring; 24. Elastic washer; 25. Lead wire fixing cap; 28. Rectifier tube fixing seat; 29. Bolt; 34. Transducer diversion cover; 341. Groove under the diversion cover; 301. A, B glue; 302. Ceramic sheet; 303. PCB; 304. Socket; 305. Plug; 26. Fixed bolt; 261. fixed bolt rod; 262. outer wire nut; 263. spring; 112. blind hole; 443. blind hole; 331. upper support column; 332. lower support column; 44. Rectifier tube; 441. Seal ring; 442. Laser welding seam; 55. Instrument circuit box; 55A. Instrument circuit box lower shell; 55B. Instrument circuit box upper shell; PCB; 554. Display screen; 555. Battery; 56. Transducer signal line; 27. Temperature sensor fixing seat; 271. Temperature sensor.

Detailed ways

The implementation of the present invention will be described in further detail below in conjunction with the accompanying drawings and examples.

Embodiment one:

As shown in Figure 1, it is a DN15 caliber through-beam type ultrasonic water meter transducer lead wire and sealing structure, including an equal-diameter stainless steel 304 metal outer tube 11 with a thickness of 2.5mm, a special-shaped transducer, a rectifier tube 44, and a transducer Energy device lead-out line fixing seat 22, transducer lead-out line fixing head 23, water meter instrument circuit box 55, lead-out line fixing cap 25; said DN15 caliber straight-through through-beam ultrasonic water meter, the outer tube body of the base meter is equal diameter The metal outer tube 11; the special-shaped transducer is composed of a special-shaped transducer structural part 33 and a transducer guide cover 34. Since the transducer lead-out line and the structure of the sealing method have undergone a qualitative change, it can achieve The two ends can be placed in the two ends of the equal-diameter metal outer pipe 11 without being fixed by a pressure ring, and its special structure meets the minimum water gap > 3mm in the flow channel. Therefore, it is solved that according to the patent announcement number CN 208223575 U, it is necessary to adopt a large-to-small conversion joint to be connected to the two ends of the straight pipe and converted into a DN15 caliber mode. Therefore, the distance between the emitting surfaces of the two transducers can be maximized, that is, the sound path can be maximized; the two transducer structures 33 are connected by a reduced-diameter rectifier tube 44 to form a pair of through-beam transducers. The overall structure of the lining; under the cooperation of the equal-diameter metal outer tube 11 as the center structure, the transducer lead-out wire fixing seat 22, the transducer lead-out wire fixing head 23, the water meter circuit box 55, and the lead-out wire fixing cap 25, the composition The DN15 caliber through-beam ultrasonic water meter is used to maximize the measurement turndown ratio and minimize the starting flow value.

The middle part of the special-shaped transducer structure 33 is equipped with a transducer ceramic sheet assembly 30; the middle part of the special-shaped transducer structure 33 is connected to the inner side of the outer ring by an upper support column 331 and a lower support column 332; The positioning and fixing bolt 26 is installed in the lower supporting column 332 of the energy device; the positioning and fixing bolt 26 is positioned by the positioning blind hole 112; The other end communicates with the central through hole of the transducer lead-out wire fixing head 23, and the transducer signal lead-out wire 56 is drawn from the center of the transducer through the lead-out oblique hole 334 and the center hole of the lead-out wire fixing head 23 to the integration circuit at PCB553.

The function of the inclined hole 334 for the lead-out line of the transducer in the middle of the upper support column 331 is: although the fixing seat 22 for the lead-out line of the transducer is located on the inner side of the pipe thread 111 at both ends of the equal-diameter metal outer tube 11, since the lead-out line 56 can Lead out through the inclined hole 334 of the lead wire, so the special-shaped transducer structure 33 can be installed as close as possible to the inner sides of the two ends of the equal-diameter metal outer tube 11 without considering the problem that the lead-out wire fixing seat 22 of the transducer is located on the inner side of the pipe thread 111. Therefore, it is possible to effectively increase the distance between the emitting surfaces of the two transducers as much as possible, that is, to increase the sound path and increase the range ratio R.

As shown in accompanying drawing 6, since there is a transducer in the middle part of the special-shaped transducer structure 33, the gap, that is, the cross-sectional area where the fluid passes is the smallest, so the middle part of the special-shaped transducer structure and the inside of the outer ring in this embodiment are respectively The upper support column 331 and the lower support column 332 are connected by two support columns instead of multiple, which helps to increase the cross-sectional area of the water and reduce the pressure loss.

The transducer lead wire fixing seat 22 is located outside the equal diameter metal outer pipe 11 of the flowmeter base meter and the inner side of the metal outer pipe external thread 111; the transducer lead wire fixing seat 22 and the equal diameter metal outer pipe 11 Connected by laser welding; the transducer lead wire fixing head 23 is located at the lower end of the transducer lead wire fixing seat 22, and its side has a sealing ring 232 to seal with the inside of the transducer lead wire fixing seat 22, and is fixed by the lead wire The positioning platform 233 in the seat 22 is used for height positioning to ensure the height and smoothness of the lead wire fixing head 23. It ensures that the lead wire fixing head 23 lower end sealing ring 231 has a reasonable amount of compression, and can also make the lead wire fixing head The lower part of 23 is embedded in the special-shaped transducer structure 33 to play the role of positioning and fixing the special-shaped transducer structure 33 . The elastic washer 24 is located above the lead wire fixing head 23 and below the lead wire fixing nut 25 , and the lead wire fixing nut 25 compresses and fixes the transducer lead wire fixing head 23 by applying force to the elastic washer 24 .

The connection between the necked rectifier tube 44 and the transducer structural parts 33 at both ends is completed by gluing or laser welding at the seams (laser welding has been widely used in metal and plastic welding at present) , forming an overall structure of a pair of through-beam transducer lining tubes. This stable structure can ensure a constant distance between the emitting surfaces of the two transducers, and can greatly improve the consistency of mass production performance of the flowmeter. The sealing ring 441 on the necking rectifying tube 44 plays the role of fixing the rectifying tube and blocking water with the inner wall of the metal tube during installation, and does not play an integral sealing role.

The overall structure of the lining tube body of the double-beam type transducer is fixed by pressing and fixing the lead wire fixing head 23 from the upper part of the casing, and the positioning and fixing bolt 26 is supported from the transducer structure 33. Carry out lower positioning and fixing in 332. The fixed bolt 26 is located in the lower support column 332 of the transducer. Further, the fixed bolt 26 is composed of an outer wire nut 262, a fixed bolt rod 261 and a spring 263. The inner hole of the fixed bolt 26 is a hexagonal hole with an outer wire nut 262. It is screwed into the inner thread of the lower support column 332 for fixing, and the fixed bolt rod 261 is snapped into the corresponding blind hole 112 inside the equal-diameter metal outer tube 11 to complete the positioning. The installation of fixed bolt 26: the fixed bolt assembly, namely spring 263, fixed bolt rod 261 is inserted in the blind hole of support column band internal thread 332 under the special-shaped transducer structure, and the outer thread nut 262 of the fixed bolt is tightened.

As shown in accompanying drawing 1, the overall structural length 333 of the liner body of the double-opposing transducer is 0.3 mm less than that of the metal outer pipe with equal diameter on one side, and its function is to remove the sealant when the flowmeter joint is installed. The extrusion force on the gasket is mainly received by the metal nozzle of the butt joint, which can effectively protect the inner liner and make it less stressed and not deformed during long-term use.

The installation of inserting the overall structure of the lining tube body of the through-beam transducer into the metal outer tube 11 of equal diameter: press the fixing bolt 261 to retract the head, and insert one end of the transducer sleeve into the metal outer tube 11 . Note that the position of the blind hole 112 corresponding to the inner side of the metal outer tube 11 must be staggered, that is, do not let the unilateral fixing bolt 261 enter the blind hole 112, press the other end of the fixing bolt 261, and put the transducer sleeve After all the tubes are inserted into the metal outer tube, use a fork-shaped tool to clamp the two transducer support columns 331, 332, and rotate the transducer sleeve so that the two fixing bolts 261 at both ends enter the respective blind holes 112 at the same time , to complete the installation and fixation.

This embodiment, as shown in Figure 1, is a DN15 diameter metal tube with a wall thickness of 2.5mm (the height of the outer thread is about 1.2mm). The lead-out line of the device is exported to the middle of the tube, so the thickness of the plastic outer tube is 1.8mm, which fully meets the strength requirements. Then, after the structure of the DN15 caliber outer tube is improved, it can be calculated that the minimum gap between the structural parts of the special-shaped transducer inside the equal-diameter metal outer tube is:

(26.44mm-2×2.5mm-2×1.8mm-10mm)/2=7.84mm/2=3.92mm>3mm, which can fully meet the requirements for the smooth passage of impurities, compared with the outer tube in the patent authorization announcement number CN 211317425 U saving materials;

The ceramic sheet assembly 30 of the transducer is characterized in that the ceramic sheet assembly is placed in the blind hole of the special-shaped transducer structure, including the ceramic sheet 302 and the bottom of the blind hole through the two-component A and B glue 301 Bonding, the positive and negative poles of the ceramic sheet are welded on the PCB303, and the lead wire 56 is also welded on the PCB303.

The assembly process of the described transducer lead wire 56: package in the blind hole of the special-shaped transducer structure, after installing the ceramic sheet 302 and PCB303, weld the lead wire 56. At this time, do not install the rectifying cover 34, but The integral inner lining sleeve is inserted into the metal pipe 11, and the two fixing bolts 261 are inserted into the respective blind holes 112 of the metal inner tube to fix the integral inner lining sleeve. Thereafter, the lead-out wire of the transducer is passed through the lead-out inclined hole 334, and passed out from the lead-out wire fixing base 22, after which the rectifying cover 34 can be buckled, and the installation and lead-out of the transducer installed in the equal-diameter metal outer tube are completed. The lead out of the line. In order to achieve IP68 waterproof, use a flat-head thin tube to inject two-component A and B glue waterproof curing glue into the transducer from the lead-out wire fixing seat through the lead-out oblique hole 334, so that the structural parts of the special-shaped transducer and The transducer guide cover 34 is closely integrated. It should be noted that the thin groove 341 on the outer ring of the lower part of the transducer flow guide cover 34 is combined with glue A and B, so that the transducer flow guide cover 34 and the special-shaped transducer structure 33 can be combined into a solid one.

The meter circuit box 55 of the water meter is located outside the equal-diameter metal outer tube 11 of the flowmeter base meter, and is composed of a meter circuit box lower shell 55A and a meter circuit box upper shell 55B. The integrated circuit board 553 , the instrument display screen 554 and the battery 555 are located in the instrument circuit box 55 . The lower case 55A of the instrument circuit box is cylindrically fitted with the outer ring of the transducer lead wire fixing seat 22, and there is a sealing ring 221 between the two for sealing. The lead wire fixing nut 25 has two functions: one, it compresses the transducer lead wire fixing head 23 by applying force to the elastic washer 24; the second function is to compress the lower shell of the circuit meter box 55A. Like this, applied extremely frugal, simple method and just finished fixing to circuit meter box bottom case 55A. According to actual needs, waterproof glue can be filled in the circuit box of the circuit meter to make it reach the IP68 protection level.

Embodiment two:

As shown in Figures 4 and 7, it is a DN15 caliber through-beam ultrasonic water meter transducer lead wire and sealing structure, including an equal-diameter stainless steel 304 metal outer tube 11 with a thickness of 1.6mm, a special-shaped transducer, and a rectifier. Tube 44, transducer lead wire fixing seat 22, transducer lead wire fixing head 23, water meter circuit box 55, lead wire fixing cap 25 and temperature sensor 271; the DN15 caliber through-beam type ultrasonic water meter , the base casing is an equal-diameter metal outer tube 11; the special-shaped transducer is composed of a special-shaped transducer structure 33 and a transducer guide cover 34, due to the structure of the transducer lead-out line and the sealing method It can be placed in the two ends of the equal-diameter metal outer pipe 11 without fixing the two ends with the pressure ring, and its special structure meets the minimum water gap > 3mm in the flow channel. Therefore, it is solved that according to the patent announcement number CN 208223575 U, it is necessary to adopt a large-to-small conversion joint to be connected to the two ends of the straight pipe and converted into a DN15 caliber mode. Therefore, the distance between the emitting surfaces of the two transducers can be maximized, that is, the sound path can be maximized; the two transducer structures 33 are connected by a reduced-diameter rectifier tube 44 to form a pair of through-beam transducers. The structure of the liner body; in the center structure of the equal-diameter metal outer pipe, the transducer lead wire fixing seat 22, the transducer lead wire fixing head 23, the water meter circuit box 55, the lead wire fixing cap 25, and the temperature sensor mounting seat With the cooperation of 27, a DN15 caliber through-beam ultrasonic water meter was formed, which maximized the measurement turndown ratio and minimized the initial flow value.

The middle part of the special-shaped transducer structure 33 is equipped with a transducer ceramic chip assembly 30; the middle part of the special-shaped transducer structure 33 is connected to the inner side of the outer ring by an upper support column 331 and a lower support column 332; The inner hole of the support column 331 is a lead-out oblique hole 334, one end of which communicates with the middle of the transducer, and the other end communicates with the center through hole of the transducer lead-out fixed head 23, and the transducer signal lead-out line 56 passes through the center of the transducer. The inside is drawn out through the inclined hole 334 of the lead-out line and the central hole of the lead-out line fixing head 23 .

The function of the inclined hole 334 for the lead-out line of the transducer in the middle of the upper support column 331 is: although the fixing seat 22 for the lead-out line of the transducer is located on the inner side of the pipe thread 111 at both ends of the equal-diameter metal outer tube 11, since the lead-out line 56 can Lead out through the inclined hole 334 of the lead wire, so the special-shaped transducer structure 33 can be installed as close as possible to the inner sides of the two ends of the equal-diameter metal outer tube 11 without considering the problem that the lead-out wire fixing seat 22 of the transducer is located on the inner side of the pipe thread 111. Therefore, it is possible to effectively increase the distance between the emitting surfaces of the two transducers as much as possible, that is, to increase the sound path and increase the range ratio R.

Since the gap of the transducer in the middle part of the special-shaped transducer structure 33 and the cross-sectional area where the fluid passes are the smallest, the middle part and the inner side of the outer ring of the special-shaped transducer structure described in this embodiment are respectively supported by the upper support column 331 and the lower support column. The column 332 is connected with two support columns instead of multiple, which helps to increase the cross-sectional area of the water and reduce the pressure loss.

The transducer lead wire fixing seat 22 is positioned at the outer side of the equal-diameter metal outer pipe 11 of the flowmeter base meter and the inner side of the metal outer pipe external thread 111; the transducer lead wire fixing seat 22 and the rectifier tube fixing seat 28 and temperature The sensor fixing seat 27 is connected with the metal outer tube 11 of equal diameter by laser welding; the transducer lead-out line fixing head 23 is located at the lower end of the transducer lead-out line fixing seat 22, and there is a sealing ring 232 on the side to connect with the transducer lead-out line. The inner side of the wire fixing seat 22 is sealed, and the positioning table 233 in the lead wire fixing seat 22 is used for height positioning to ensure the height and smoothness of the lead wire fixing head 23. The amount of compression, and the lower part of the lead wire fixing head 23 can be embedded inside the special-shaped transducer structure to play the role of positioning and fixing the special-shaped transducer structure 33. The elastic washer 24 is located above the lead wire fixing head 23 and below the lead wire fixing nut 25 , and the lead wire fixing nut 25 compresses and fixes the transducer lead wire fixing head 23 by applying force to the elastic washer 24 .

The connection between the necked rectifier tube 44 and the transducer structural parts 33 at both ends is completed by gluing or laser welding at the seams (laser welding has been widely used in metal and plastic welding at present) , forming an overall structure of a pair of through-beam transducer lining tubes. For the equal-diameter metal outer tube 11 with a thinner tube wall, as shown in FIG. 4 , the middle part of the necked rectifying tube 44 is sealed and fixed by the bolt 29 and the sealing ring 291 in the rectifying tube fixing seat 28 . The sealing ring 441 on the necking rectifying tube 44 plays the role of fixing the rectifying tube and blocking water with the inner wall of the metal tube during installation, and does not play an integral sealing role.

For the overall structure of the inner liner body of a pair of opposite-beam transducers installed in the thin tube, in addition to being fixed by bolts 29 and sealing rings 291 in the rectifying tube fixing seat 28, two lead-out wire fixing heads 23 are coordinated, from The upper part of the casing is pressed and fixed to form three positions for positioning and fixing. This stable structure can ensure that the overall structure of the transducer lining body, that is, the distance between the emitting surfaces of the two transducers remains constant, and can greatly improve the consistency of mass production performance of the flowmeter.

Installation process: Insert the overall structure of the liner tube body of the through-beam transducer into the metal outer tube 11 of equal diameter, and tighten the bolt 29 with the sealing ring 291 in the rectifier tube fixing seat 28 and fix it on the necking In the blind hole 443 of the rectifying tube 44, the fixing of the integral lining tube is completed.

The overall structural length 333 of the liner body of the pair of opposite-beam transducers is 0.3 mm less than that of the metal outer tube with equal diameter on one side, and its function is to reduce the extrusion force on the sealing rubber pad when the flowmeter joint is installed. It is mainly accepted by the metal nozzle of the butt joint, which can effectively protect the lining pipe and make it less stressed and not deformed during long-term use.

Present embodiment such as shown in accompanying drawing 4, is DN15 caliber, and wall thickness is 1.6mm. The outer diameter of the thread remains unchanged at 26.44mm, and the threaded casing has a length of 11mm, a thickness of 2.0mm (among them, the height of the outer thread is 1.2mm), and an inner diameter of 22.44mm; the wall thickness of the equal-diameter metal outer tube is 1.6 mm, the diameter of both ends is 0.3mm, and the length is 11mm; the casing with a length of 11mm and a thickness of 2.0mm and an external thread is placed on the outside of the two ends of the metal outer tube with a wall thickness of 1mm after the turning, and the laser is used. Weld the threaded casing and the metal outer tube with 0.3mm cut off on one side at the joints at both ends to form a whole, from which the minimum gap between the equal-diameter metal outer tube and the special-shaped transducer can be calculated as :

(26.44mm-2×3mm-2×1.8mm-10mm)/2=6.84mm/2=3.42mm>3mm. As a result, impurities can be passed through smoothly and materials can be saved compared with the outer tube in the patent authorization announcement number CN 211317425 U.

The transducer ceramic sheet assembly 30 is characterized in that the ceramic sheet assembly is placed in the blind hole of the special-shaped transducer structure, including the ceramic sheet 302 passing through the two-component A, B glue 301 and the blind hole The bottom is bonded, the positive and negative electrodes of the ceramic sheet are welded on the PCB303, and the lead wire 56 is also welded on the PCB303.

The assembly process of the described transducer lead wire 56: package in the blind hole of the special-shaped transducer structure, after installing the ceramic sheet 302 and PCB303, weld the lead wire 56. At this time, do not install the rectifying cover 34, but The integral inner lining sleeve is inserted into the metal pipe 11, and the two fixing bolts 261 are inserted into the respective blind holes 112 of the metal inner tube to fix the integral inner lining sleeve. After this, the transducer lead-out wire is passed through the lead-out wire oblique hole 334 again, passes through the lead-out wire holder 22, after this the rectification cover 34 can be buckled, and the installation and installation of the special-shaped transducer in the equal-diameter metal outer pipe have been completed. The lead-out of the lead-out line. In order to achieve IP68 waterproof, use a flat-head thin tube to inject two-component A and B glue waterproof curing glue into the transducer from the lead-out wire fixing seat through the lead-out oblique hole 334, so that the structural parts of the special-shaped transducer and The transducer guide cover 34 is closely integrated. It should be noted that the thin groove 341 on the lower outer ring of the transducer flow guide cover 34 is combined with A and B glues, so that the transducer flow guide cover 34 and the special-shaped transducer structure can be combined into a solid one.

The meter circuit box 55 of the water meter is located outside the equal-diameter metal outer tube 11 of the flowmeter base meter, and is composed of a meter circuit box lower shell 55A and a meter circuit box upper shell 55B. The integrated circuit board 553 , the instrument display screen 554 and the battery 555 are located in the instrument circuit box 55 . The lower case 55A of the instrument circuit box is cylindrically fitted with the outer ring of the transducer lead wire fixing seat 22, and there is a sealing ring 221 between the two for sealing. The lead wire fixing nut 25 has two functions: one, it compresses the transducer lead wire fixing head 23 by applying force to the elastic washer 24; the second function is to compress the lower shell of the circuit meter box 55A. Like this, have applied extremely frugal method and have just finished fixing to circuit meter box bottom case 55A. According to actual needs, waterproof glue can be filled in the circuit box of the circuit meter to make it reach the IP68 protection level.

For this embodiment, it is necessary to measure the heat energy carried by the fluid, so in addition to flow measurement, a temperature sensor 271 also needs to be installed. Because there is no need for a waterproof seal between the inner liner integral sleeve formed by the special-shaped transducer and the rectifier tube 44 and the inner side of the metal outer tube, so for temperature measurement, when inserting the temperature sensor 271 in the temperature sensor holder 27, due to the metal outer tube The outer end is close to the water outlet, so the temperature sensor can be conveniently placed outside the diversion cover of the water outlet, and the temperature measuring rod of the temperature sensor will not affect the measurement of the fluid.

Through the above two illustrations, a kind of DN15 caliber straight-through ultrasonic water meter, heat meter and transducer lead wire and sealing structure in the present invention have been implemented and applied, but the present invention is not limited to the above-mentioned specific examples. Any modification or deformation made in the content of the present invention belongs to the protection scope of the present invention.

Claims (15)

1.A DN15 caliber correlation type ultrasonic water meter transducer outgoing line and a sealing structure are characterized by comprising a straight-through equal-diameter metal outer pipe (11) and three external threads forming structures thereof, a special-shaped transducer, a rectifier tube (44), a transducer outgoing line fixing seat (22), a transducer outgoing line fixing head (23), a water meter circuit box (55) and an outgoing line fixing cap (25); the base meter shell of the DN15 caliber correlation ultrasonic water meter is an equal-diameter metal outer pipe; the special-shaped transducer consists of a special-shaped transducer structural part (33) and a transducer flow guide cover (34) and is arranged at two ends in the equal-diameter metal outer pipe (11); the two transducers are connected by a reducing rectifier tube (44) to form a dual-correlation transducer lining integral structure; under the given length of a straight through pipe of the ultrasonic water meter, for the most common household DN15 caliber, under the structural cooperation of the special-shaped transducer, a transducer outgoing line and a sealing mode, transducer structural parts can be arranged and fixed at two ends of the inner side of the equal-diameter metal outer pipe without adopting a press ring for fixing, so that the minimum water clearance in a flow channel of the water meter flow meter is larger than 3mm, the defect that the existing DN15 caliber transducer is installed in a correlation mode, and a pipe body interface of the transducer is forced to adopt a fussy conversion joint with a large diameter and a small diameter is overcome, therefore, a stable maximum distance (sound path) is obtained between the transmitting surfaces of the two transducers, and the assembly is convenient to assemble; the DN 15-caliber correlation type ultrasonic water meter is formed by taking an equal-diameter metal outer pipe (11) as a central framework and coordinating with a transducer outgoing line fixing seat (22), a transducer outgoing line fixing head (23), a water meter circuit box (55) and an outgoing line fixing cap (25), and the maximization of a measuring range ratio, the minimization of an initial flow, the high precision of measurement and the high consistency of batch production are realized.

2. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: the middle part of the special-shaped transducer structural part (33) is provided with a transducer ceramic plate assembly (30); the middle part of the special-shaped transducer structural part (33) is connected with the inner side of the outer ring through an upper support column (331) and a lower support column (332) respectively; a positioning fixing bolt (26) is arranged in the transducer lower supporting column (332); the positioning fixing bolt (26) is positioned by the positioning blind hole (112); the inner hole of the upper support column (331) is an outgoing line inclined hole (334), one end of the inner hole is communicated with the middle inside of the transducer, the other end of the inner hole is communicated with a central through hole of the outgoing line fixing head (23) of the transducer, and the outgoing line (56) of the transducer is led out to the position of an integrating circuit PCB (553) through the outgoing line inclined hole (334) and the central hole of the outgoing line fixing head (23) from the inside of the transducer.

3. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: the middle part of the special-shaped transducer structural part (33) is connected with the inner side of the outer ring only by an upper support column (331) and a lower support column (332), so that the blocking of the transducer part to water flow is reduced, the water passing sectional area is increased, and the pressure loss formed by water resistance is reduced.

4. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: the transducer outgoing line fixing seat (22) is positioned on the outer side of the flow meter base meter equal-diameter metal outer pipe (11) and the inner side of the outer metal pipe external thread (111); the transducer outgoing line fixing seat (22) is connected with the equal-diameter metal outer pipe (11) through laser welding; the transducer leading-out wire fixing head (23) is positioned at the lower end inside the transducer leading-out wire fixing seat (22), a sealing ring (232) is arranged on the side surface of the transducer leading-out wire fixing head and is sealed with the inner side of the transducer leading-out wire fixing seat (22), the height positioning is carried out by a positioning table (233) in the leading-out wire fixing seat (22) so as to ensure the height and the flatness of the leading-out wire fixing head (23), the reasonable compression amount of the sealing ring (231) at the lower end of the leading-out wire fixing head (23) is ensured, the lower part of the leading-out wire fixing head (23) can be embedded into the special-shaped transducer structural part (33), and the functions of positioning and fixing the special-shaped transducer structural part (33) are achieved; furthermore, a sealing ring (231) below the leading-out wire fixing head (23) is used for sealing the transducer structural part (33); the sealing ring (232) is used for sealing the inner side of the lead-out wire fixing seat (22).

5. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: the elastic washer (24) is located above the outgoing line fixing head (23) and below the outgoing line fixing nut (25), and the outgoing line fixing nut (25) presses and fixes the outgoing line fixing head (23) of the transducer by applying force to the elastic washer (24).

6. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: the connection between the reducing rectifier tube (44) and the transducer structural members (33) at two ends is completed in an adhesive mode or a laser welding mode at seams, and a double-opposed-jet transducer lining tube body integral structure is formed.

7. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: the integral structure of the lining tube body of the dual-correlation type transducer can be arranged on the outer side of an equal-diameter metal outer tube (11), the tube thickness of the integral structure can meet the requirement that when a tube thread (111) is directly machined, the integral structure of the lining tube body of the dual-correlation type transducer is fixed by a leading-out wire fixing head (23) in a pressing mode from the upper portion of a sleeve, and two positioning fixing bolts (26) perform lower portion positioning and fixing from a lower supporting column (332) of a transducer structural part (33); the fixing bolt (26) is positioned in the lower transducer supporting column (332), and further, the fixing bolt (26) consists of an external thread nut (262), a fixing bolt rod (261) and a spring (263); the fixing bolt (26) is screwed into the internal thread of the lower support column (332) by an external thread nut (262) with an internal hole being a hexagonal hole, and is clamped into a corresponding blind hole (112) on the inner side of the equal-diameter metal outer tube (11) by a fixing bolt rod (261) to complete positioning; mounting of the fixing bolt (26): and (3) inserting a fixing bolt assembly, namely a spring (263) and a fixing bolt rod (261) into a blind hole of a lower support column (332) of the special-shaped transducer structural part, and screwing an outer screw nut (262) of the fixing bolt.

8. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: the length (333) of the integral structure of the lining pipe body of the dual-correlation type transducer is 0.3mm less than that of the single side of the equal-diameter metal outer pipe, and the length is used for effectively protecting the lining pipe, so that the lining pipe is stressed less and cannot deform after long-term use.

9. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: the integral structure of the lining pipe body of the correlation type transducer is inserted into the equal-diameter metal outer pipe (11) for installation: pressing the fixing bolt rod (261) to retract the head of the fixing bolt rod, and inserting one end of the transducer sleeve into the metal outer pipe (11); note that the position of the blind hole (112) corresponding to the inner side of the metal outer tube (11) is staggered, namely, firstly, a single-side fixing bolt (261) is not required to enter the blind hole (112), after the other end fixing bolt (261) is pressed, and the transducer sleeve is completely inserted into the metal outer tube (11), two transducer support columns (331) and (332) are clamped by using a tool, and the transducer sleeve is rotated, so that the two fixing bolts (261) at the two ends simultaneously enter the respective blind holes (112), and the installation and the fixation are completed.

10. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: the two ends of the equal-diameter metal outer pipe (11) are provided with pipe threaded interfaces (111) which have three forming modes: firstly, the thickness of the wall can meet the requirement that the equal-diameter metal outer pipe of a pipe thread connector can be directly turned out on the outer pipe; secondly, when an equal-diameter metal outer pipe with a thinner thickness is selected, a processed sleeve (112) with external threads is sleeved on the equal-diameter metal outer pipe, and the equal-diameter metal outer pipe is fixed by laser welding; thirdly, when an equal-diameter metal outer pipe with moderate thickness is selected, a part of the wall thickness is turned, a processed sleeve pipe (112) with external threads is just sleeved, and the machined sleeve pipe and the processed sleeve pipe are fixed by laser welding; the three types of threaded interfaces can ensure that the minimum clearance between the inside of the equal-diameter metal outer pipe and the special-shaped transducer is larger than 3mm, completely meet the requirement of smooth passing of impurities, the first mode is convenient to process, and the second mode and the third mode can save the material of the outer pipe.

11. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: for the external thread forming mode of adopting the equal-diameter metal thin pipe, a lining pipe integral structure of a dual-correlation type transducer is formed by connecting two transducer structural parts with a reducing rectifier tube, and the positioning and fixing modes are as follows: the middle part of the necking down rectifier tube (44) is sealed and fixed through a bolt (29) and a sealing ring (291) in a rectifier tube fixing seat (28), and two ends of the necking down rectifier tube are pressed and fixed from the upper part of the sleeve through two outgoing line fixing heads (23), so that three positioning and fixing points are formed on the whole structure of the lining tube body, and the necking down rectifier tube is very firm.

12. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: after the ceramic plates (302) and the PCB (303) are packaged, adhered and installed in the blind holes of the special-shaped transducer structural member, the outgoing line is welded on the PCB (303), at this time, the rectifying cover (34) is not needed to be installed, the integral inner bushing is inserted into the metal tube, the two fixing bolts (26) are inserted into the respective blind holes (112) of the metal inner tube, and the integral inner bushing is fixed; then, the leading-out wire (56) of the transducer penetrates through the leading-out wire inclined hole (334) and penetrates out of the leading-out wire fixing seat (22); then, a rectifying cover (34) can be buckled, and the assembly and the leading-out of the transducer and the leading-out wire in the equal-diameter metal outer tube are completed; in order to realize IP68 water prevention, a flat-head thin tube is used for injecting double-component glue A and double-component glue B waterproof curing glue into the transducer from the leading-out wire fixing seat (22) through the leading-out wire inclined hole (334), so that the special-shaped transducer structural part and the transducer flow guide cover are tightly combined into a whole.

13. The outgoing line and the sealing structure of the DN15 caliber correlation type ultrasonic water meter transducer are characterized in that: the transducer lead-out wire (56) is butted with an internal connecting socket (304) and an external connecting plug (305) and is led out from a port of a lead-out wire fixing seat (22): the socket (304) is fixed in the socket fixing hole, the bottom of the socket is welded and communicated with the positive electrode and the negative electrode of the ceramic chip (302) on the PCB (303) through conducting wires, therefore, before the bushing pipe in the whole transducer is not inserted into the metal pipe, double-component glue A and double-component glue B waterproof curing glue can be injected into the transducer, and then the rectifying cover is buckled, so that the special-shaped transducer structural member (33) and the transducer diversion cover (34) are tightly combined into a whole.

14. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: the water meter circuit box (55) is positioned on the outer side of the equal-diameter metal outer pipe (11) of the flowmeter base meter and consists of a meter circuit box lower shell (55A) and a meter circuit box upper shell (55B); the integrating circuit board (553), the instrument display screen (554) and the battery (555) are positioned in the instrument circuit box (55); the lower shell (55A) of the instrument circuit box is in cylindrical fit with the outer ring of the transducer outgoing line fixing seat (22), and a sealing ring (221) is arranged between the lower shell and the outer ring for sealing; the lead wire fixing nut (25) has two functions: firstly, the fixing head (23) of the leading-out wire of the transducer is pressed tightly by applying force to an elastic gasket (24); the second function is to press the lower shell (55A) of the circuit instrument box; thus, the fixation of the bottom shell (55A) of the circuit instrument box is completed by applying an extremely simple method; according to actual requirements, waterproof glue can be filled and sealed in the circuit box (55) of the circuit instrument, so that the protection level of the circuit instrument reaches IP 68.

15. The outgoing line and the sealing structure of the transducer of the DN15 caliber correlation type ultrasonic water meter, which are described in claim 1, are characterized in that: a straight-through pipe structure with DN15 caliber facilitates the laser welding of the temperature sensor fixing seat (27) and the installation of the temperature sensor (271) at the outer end of the water outlet of the outer metal pipe, thereby facilitating the heat energy metering.

Images