Structure of direct reading counter and mechanical meter with the same

Abstract

A structure of a direct-reading counter with a simple structure, low cost, and easy and quick assembly, and a mechanical meter with the structure. It adopts a permanent magnetic sheet and an angle sensor assembly. By reading the rotation angle information of the transmission intermediate wheel between the middle drive coupling wheel and the gear transmission assembly, the rotation angle position of the unit word wheel can be known, and the reading value of the word wheel of each magnitude in the word wheel group can be deduced by the carry information. By reading the dynamic and static states of the monitoring pointer, the time node of the angle sensor to collect the rotation position information of the permanent magnetic sheet can be adjusted in a targeted manner. By collecting the cumulative number of rotations of the monitoring pointer, the carry missed detection defect generated when the unit word wheel corresponding to the permanent magnetic sheet rotates from the number 9 to the number 0 is corrected. The mechanical meter adopting the structure of the present invention has good waterproof, dustproof and corrosion resistance, is easy to disassemble and assemble, and is convenient for detection, maintenance and replacement, and the component investment cost is low.

Description

Technical Field

[0001] The present invention relates to a counter structure for measuring fluid flow and a meter with the structure, and in particular to a counter structure for acquiring a word wheel count value representing the flow by collecting the rotation state of an intermediate wheel using an angle sensor and a meter with the structure. Background Art

[0002] The invention patent application (titled "Electronic Direct Reading Counter for Meters" and published as CN 102628703A) filed by the present applicant with the State Patent Office on March 1, 2012 discloses a technical solution, which is to provide a set of angle sensing components (including permanent magnetic sheets, magnetic induction angle sensors and magnetic shielding sheets) for each character wheel in a character wheel group for digitally displaying measurement values ​​of a meter, and the component can collect the rotation position of the corresponding character wheel in real time and upload the value displayed by the corresponding character wheel to the main control circuit of the meter.

[0003] The above structure can accurately calculate the rotation position of each character wheel in the character wheel group, so as to accurately calculate the corresponding displayed value of each character wheel in the character wheel group, but it still has the following shortcomings:

[0004] 1. The structure is complicated. It is necessary to set relevant magnetic sheets (permanent magnetic sheets or shielding magnetic sheets) on the left and right sides of each character wheel. At the same time, it is necessary to set an angle sensor that can identify the rotation angle of the permanent magnetic sheet of the corresponding character wheel on one side of each character wheel. So many components are set in the narrow space between two adjacent character wheels, and the structure is complicated and difficult to install.

[0005] 2. High cost. A set of the angle sensing components is provided for each character wheel, which results in a large investment in the components of the meter and a high cost, especially the high price of the high-precision angle sensor. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a direct reading counter structure which is simple in structure, low in cost and easy to assemble quickly and a mechanical meter with the structure.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] The structure of the direct reading counter for a mechanical meter of the present invention comprises a character wheel group composed of a plurality of character wheels for displaying a high-position metering value in digital form, a gear transmission assembly arranged under a transparent meter cover made of non-magnetic material, and a driving wheel driven by the flow of a metering fluid, wherein the driving wheel is meshed with a driving gear of the lowest order in the gear transmission assembly, each character wheel in the character wheel group is connected together through a character wheel shaft, and a carry coupling wheel is arranged between two adjacent character wheels, characterized in that: the driving gear of the highest order in the gear transmission assembly drives the rotation of the unit character wheel in the character wheel group by meshing with a transmission intermediate wheel and a middle drive coupling wheel in turn, a permanent magnetic sheet is arranged at the center of the upper surface of the transmission intermediate wheel, a magnetic induction angle sensor is arranged at a position opposite to the permanent magnetic sheet outside the transparent meter cover, the angle sensor collects the position of the rotation angle of the permanent magnetic sheet at a set frequency, and the main control circuit of the meter stores the collected rotation angle of the permanent magnetic sheet and the display value corresponding to the rotation angle and the unit character wheel in a storage unit of the main control circuit.

[0009] The transmission ratio among the intermediate transmission wheel, the middle drive coupling wheel and the units wheel is 1:1:1.

[0010] A plurality of pointer disks are provided under the transparent cover and opposite to the character wheel set, and the pointers are rotated to display the low-position metering values. Each pointer is fixedly connected to a single-stage driving gear in the gear transmission assembly.

[0011] A monitoring pointer that reflects whether the metering fluid is flowing is also provided next to the pointer disk under the transparent meter cover. The monitoring pointer is fixedly connected to a monitoring gear provided under the transparent meter cover, and the monitoring gear is meshed with the lowest-level driving gear. A monitoring sensor is provided at a position corresponding to the monitoring pointer outside the transparent meter cover, and the monitoring sensor stores the rotation state of the monitoring pointer and the accumulated number of rotations of the monitoring pointer in the storage unit.

[0012] The monitoring sensor is an electromagnetic induction sensor, a magnetic induction sensor, a photoelectric sensor, a rheostat, a varactor, or a travel switch.

[0013] The main control circuit, angle sensor and monitoring sensor are assembled in a "U"-shaped plastic shell cavity, and the plastic shell cavity is fixed to the outside of the transparent cover with a building block-type quick disassembly structure.

[0014] A trigger program is provided in the main control circuit to start the angle sensor to collect the rotation position information of the permanent magnetic piece at the set frequency according to the movement state of the monitoring pointer. When the cumulative number of rotations of the monitoring pointer collected twice in the set frequency is the same, the angle sensor will remain passive or dormant.

[0015] The main control circuit is also provided with a zeroing module for forcibly returning the accumulated electronic counting number of rotations of the monitoring pointer to zero when the permanent magnetic sheet rotates to make the counting value of the units wheel at a plurality of set positions.

[0016] The mechanical direct-reading water meter of the present invention comprises an impeller box, an impeller, a counter box and a transparent meter cover for sealing the meter case, the counter box is sealed and arranged on the impeller box, an upper clamping plate and a lower clamping plate are arranged in the counter box, a gear transmission assembly and a character wheel group consisting of a plurality of character wheels which display the flow in digits are arranged between the upper clamping plate and the lower clamping plate, a carry coupling wheel is arranged between adjacent character wheels, the impeller drives the lowest-order driving gear in the gear transmission assembly to rotate through the driving wheel, and is characterized in that: the structure of the transmission intermediate wheel and the middle-drive coupling wheel involved in the structure of the direct-reading counter for a mechanical meter of the present invention is arranged between the highest-order driving gear in the gear transmission assembly and the unit-digit wheel in the character wheel group.

[0017] In the mechanical direct-reading water meter of the present invention, the structure of the direct-reading counter for the mechanical meter of the present invention is also provided under the transparent meter cover, involving the structures of the pointer plate, the monitoring pointer and the like.

[0018] The structure of the direct reading counter of the present invention adopts a permanent magnetic sheet and an angle sensor assembly. By reading the rotation angle information of the transmission intermediate wheel between the middle drive coupling wheel and the gear transmission assembly, the rotation angle position of the unit word wheel can be known, so that the reading value of the word wheel of each magnitude in the word wheel group can be calculated by the carry information. By reading the dynamic and static state of the monitoring pointer, the time node of the angle sensor collecting the rotation position information of the permanent magnetic sheet can be adjusted in a targeted manner. By collecting the cumulative number of rotations of the monitoring pointer, the carry missed detection defect caused by the non-full-digit direct reading of the counting wheel when the unit word wheel corresponding to the permanent magnetic sheet rotates from the number 9 to the number 0 can be corrected. The control circuit board and the related sensors are assembled in a plastic shell cavity that can be fixedly connected to the outside of the watch case in a building block assembly manner. The mechanical meter using the structure of the present invention has good waterproof, dustproof and corrosion resistance, is easy to disassemble and assemble, and is convenient for detection, maintenance and replacement, and the component investment cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The figure is a schematic diagram of the appearance of the meter head of the present invention.

[0020] Figure 2 for Figure 1 Schematic diagram of the appearance of the meter head after removing the control circuit board.

[0021] Figure 3 for Figure 1 A-A section view of the meter.

[0022] Figure 4 for Figure 1 Right side view.

[0023] Figure 5 for Figure 2 Schematic diagram after removing the transparent cover and upper clamp.

[0024] Figure 6 for Figure 2 Right view of .

[0025] Figure 7 for Figure 2 Left view of .

[0026] The reference numerals are as follows:

[0027] Character wheel assembly 1, unit character wheel 11, transmission intermediate wheel 2, middle drive coupling wheel 3, permanent magnetic sheet 4, angle sensor 41, pointer plate 5, pointer 51, monitoring pointer 6, monitoring gear 61, monitoring sensor 62, watch case 7, transparent watch cover 71, upper splint 72, reading window 721, gear transmission assembly 73, driving gear 731, driving wheel 732, lower splint 74, counter box 75, impeller box 76, impeller 77, control circuit board 8. DETAILED DESCRIPTION

[0028] The structure of the direct reading counter of the present invention can be applied to water meters, gas meters and flow meters for measuring other liquids with mechanical transmission structures.

[0029] The structure of the direct-reading counter of the present invention is described in detail below by taking a water meter as an example.

[0030] 1. Basic composition of water meter

[0031] like Figure 1-7 As shown, the water meter includes, from bottom to top, a meter case 7, an impeller box 76, an impeller 77, a counter box 75, a lower clamping plate 74, a gear transmission assembly 73, a character wheel assembly 1, an upper clamping plate 72, a transparent meter cover 71 and a control circuit board 8.

[0032] The impeller box 76 is installed in the meter case 7, and the impeller 77 is placed in the impeller box 76. When the metered water medium flows through the impeller box 76, the flowing water medium will drive the impeller 77 to rotate. The counter box 75 is sealed and installed on the impeller box 76, that is, a sealing rubber ring is installed between the counter box 75 and the impeller box 76 to prevent the water in the impeller box 76 from entering the counter box 75.

[0033] The upper clamping plate 72 and the lower clamping plate 74 are installed in the counter box 75, and the gear transmission assembly 73 and the character wheel group 1 are installed between the upper clamping plate 72 and the lower clamping plate 74. The upper end of the impeller 77 passes through the counter box 75 and meshes with the lowest-order driving gear 731 in the gear transmission assembly 73 through the driving wheel 732.

[0034] The character wheel set 1 is composed of a plurality of character wheels that display the flow value in numbers. All the character wheels are mounted on the character wheel shaft, and a carry coupling wheel is provided between two adjacent character wheels. Usually, the counting magnitudes displayed in the character wheel set 1 from small to large are ones, tens, hundreds, thousands and ten thousand (i.e. 10 0 ~10 4 m 3 Five orders of magnitude, or more orders of magnitude can be set), 0-9 numbers are set at equal intervals on the circumferential side wall of each character wheel, and the low-position character wheel rotates one circle, and the adjacent high-position character wheel rotates one number (that is, the low position rotates one circle and advances one position to the high position).

[0035] A reading window 721 for reading the measured value of each character wheel is provided on the upper clamping plate 72 at a position opposite to each character wheel in the character wheel set 1 .

[0036] The transparent cover 71 is made of non-magnetic material and is fixed to the top of the watch case 7. It is not only used to encapsulate the counter box 75, the upper clamping plate 72 placed in the counter box 75, the lower clamping plate 74, the gear transmission assembly 73 and the character wheel group 1 in the watch case 7, but also used to observe the measurement values ​​of each character wheel in the character wheel group 1.

[0037] 2. Structure of direct reading counter

[0038] A direct reading counter is a counter that directly reads the flow value and displays it in digital form.

[0039] 1. Basic structure

[0040] like Figure 5 As shown, a transmission intermediate wheel 2 and a middle drive coupling wheel 3 are provided between the highest-order driving gear 731 in the gear transmission assembly 73 and the units character wheel 11 in the character wheel set 1 .

[0041] The transmission intermediate wheel 2 is meshed with the highest-order driving gear 731 in the gear transmission assembly 73, and the transmission ratio therebetween is 1:10. At the same time, the transmission intermediate wheel 2 is meshed with the middle drive coupling wheel 3, and the middle drive coupling wheel 3 is parallel and coaxially arranged with the character wheel set 1, wherein the transmission intermediate wheel 2 and the middle drive coupling wheel 3 are meshed in an axially intersecting manner.

[0042] The transmission ratio among the intermediate transmission wheel 2, the middle drive coupling wheel 3 and the units wheel 11 is 1:1:1.

[0043] That is, the transmission intermediate wheel 2 rotates one circle, the middle drive coupling wheel 3 rotates one circle, the ones digit wheel 11 also rotates one circle, and the tens digit wheel accumulates one digit.

[0044] The main improvements of the present invention are:

[0045] A permanent magnetic sheet 4 is fixed at the center of the upper surface (i.e., the spoke surface) of the transmission intermediate wheel 2. Correspondingly, a magnetic induction angle sensor 41 is provided at a position opposite to the permanent magnetic sheet 4 outside the transparent meter cover 71. The angle sensor 41 can capture the rotation angle position of the permanent magnetic sheet 4 in real time, that is, when the permanent magnetic sheet 4 rotates from the initial position by 0.1, 0.2, half a circle or 0.9 circle along with the transmission intermediate wheel 2, the angle sensor 41 can detect that the positive position on the ones digit wheel 11 (i.e., the position when any number from 0 to 9 is facing the reading window) is 1, 2, 5 or 9 respectively. When the number on the ones digit wheel 11 facing the reading window changes from 9 to 0, it indicates that the ones digit wheel 11 rotates one circle, and the ten-digit carry-over is recorded in the main control circuit of the meter, and so on, thereby obtaining the numbers in the positive positions on the ones digit, tens digit, hundreds digit, thousands digit and ten thousand digit wheels, that is, the cumulative value of the flow of the meter.

[0046] The preferred setting is that the angle sensor 41 does not need to collect the angle position information of the permanent magnetic sheet 4 in real time. It can collect the information at a set frequency according to the characteristics of the nominal flow of water meters of different specifications. This is conducive to improving the service life of the angle sensor 41 and reducing the consumption of special batteries. The set frequency can be calculated on a daily basis, and the information can be collected several times a day. For example, for large water users (such as industrial and mining enterprises and other collectives), a calculation mode of daily, hourly or smaller time units can be adopted. It can also be calculated on a monthly basis, and the information can be collected several times a month. For small water users (such as families, small restaurants and other individuals), a monthly calculation mode can be adopted.

[0047] The main control circuit stores the measured value displayed by the ones-digit wheel 11 and the accumulated carry value corresponding to the rotation angle position of the permanent magnetic sheet 4 in a storage unit of the main control circuit.

[0048] The above structure only needs to set a permanent magnetic sheet 4 and a corresponding angle sensor 41 on the transmission intermediate wheel 2 to obtain the rotation position of each character wheel in the character wheel group 1. It has a simple structure, accurate counting, few electromagnetic induction components, and low material investment cost.

[0049] 2. Further improvements

[0050] like Figure 5 As shown, under the transparent meter cover 71 and opposite to the character wheel set 1, there are provided a plurality of pointer disks 5 for displaying low-level meter values ​​in the form of rotating pointers 51, such as the tenth, hundredth, thousandth and ten-thousandth digits (i.e., 10 -1 ~10 -4 m3 Four orders of magnitude), each pointer 51 is fixedly connected to a single-order driving gear 731 in the gear transmission assembly 73.

[0051] The driving gear 731 corresponding to the tenth position is meshed with the transmission intermediate wheel 2, and the transmission ratio therebetween is 10:1. From small to large, the transmission ratio between two adjacent driving gears 731 of low position measurement is 10:1.

[0052] The feature of this improvement is that a monitoring pointer 6 is provided beside the pointer disk 5 of the minimum meter level under the transparent meter cover 71 to reflect whether the water is flowing. The monitoring pointer 6 is fixedly connected to the monitoring gear 61 provided under the transparent meter cover 71, and the monitoring gear 61 is meshed with the driving gear 731 of the 1 / 10,000 meter level, and the transmission ratio therebetween is preferably 1:1. That is to say, once water flows through the water meter, the monitoring pointer 6 immediately rotates.

[0053] In order to collect information on whether the monitoring pointer 6 rotates, the present invention provides a monitoring sensor 62 at a position corresponding to the monitoring pointer 6 outside the transparent cover 71, and the monitoring sensor 62 stores the rotation state of the monitoring pointer 6 and the number of electronically counted revolutions of the monitoring pointer 6 in the storage unit. The monitoring sensor 62 is an electromagnetic induction (variable inductor) sensor, a magnetic induction sensor, a photoelectric sensor, a rheostat, a variable capacitor or a travel switch.

[0054] The main control circuit acquires whether water is flowing through the water meter by collecting the rotation state of the monitoring pointer 6, and acquires the positions of the pointers 51 on the pointer disk 5 corresponding to the ten-thousandth, thousandth, hundredth and tenth digits by collecting the cumulative number of rotations of the monitoring pointer 6, that is, the measurement values ​​of the low-level measurement values ​​are obtained.

[0055] The use of monitoring pointer 6 has the following advantages:

[0056] When the water meter is in normal continuous use, when the angle position of the permanent magnet 4 rotated by the angle sensor 41 rotates from the number 9 corresponding to the units-digit wheel 11 and passes the number 0, if only the angle sensor 41 is used to collect information, a carry missed detection defect is likely to occur (this missed detection defect is caused by the non-full-digit direct reading of the counting wheel, and "non-full-digit direct reading of the counting wheel" refers to the prior art of configuring a set of angle sensing components for each character wheel in the character wheel group), that is, if two adjacent frequencies in the set frequency fall between 9 and 0 and 0 and 1, then the angle sensor 41 will miss the collection of the carry information of the units-digit wheel 11.

[0057] A monitoring pointer 6 is used. When the above situation occurs, the main control circuit can inquire the cumulative number of rotations of the monitoring pointer 6 to infer whether the above-mentioned 9 passing 0 needs to be carried.

[0058] 3. Another improvement

[0059] A triggering program is provided in the main control circuit of the water meter to start the angle sensor 41 to obtain the rotation angle position information of the permanent magnetic piece 4 at a set frequency according to the rotation of the monitoring pointer 6.

[0060] During the normal continuous use of the water meter, the angle sensor 41 will collect the rotation of the permanent magnetic sheet 4 at the set frequency, thereby accurately recording the counting of each character wheel in the character wheel group 1. However, when the user of the water meter is away for a long time or uses water irregularly, it is possible that no water flows through the water meter for a long time, but the angle sensor 41 still collects the movement state of the permanent magnetic sheet 4 (i.e., the angular position of the rotation of the permanent magnetic sheet 4) at the set frequency, which consumes the power of the dedicated battery of the meter and reduces the use efficiency of the angle sensor 41. Therefore, through the above-mentioned triggering procedure, the use efficiency of the angle sensor 41 is improved and the energy consumption of the dedicated battery is reduced.

[0061] The trigger procedure is that once the monitoring pointer 6 rotates, the angle sensor 41 can be started to collect the position information of the rotation angle of the permanent magnetic piece 4 according to the set frequency; when the cumulative number of rotations of the monitoring pointer 6 collected twice in the set frequency is the same, the angle sensor 41 will remain passive or dormant.

[0062] This trigger procedure provides the following benefits:

[0063] For a water meter that is in a passive or dormant state for a long time, the angle sensor 41 can be kept in the passive or dormant state; once the water meter is enabled, the angle sensor 41 is automatically started to work.

[0064] 4. Another improvement

[0065] A zeroing module is also provided in the main control circuit, that is, when the number of the units wheel 11 corresponding to the rotation of the permanent magnetic sheet 4 is in multiple set positions, such as the positive position (it can also be set at a predetermined non-positive position with an equidistant pattern, such as the number on the units wheel 11 facing the reading window is 0.5, 1.5, 2.5, ... or 9.5), the accumulated electronic counting number of rotations of the monitoring pointer 6 is forced to be zeroed, which in principle eliminates the possible cumulative error defects that could not be overcome in the past.

[0066] During the counting of the monitoring pointer 6, on the one hand, the number of cumulative rotations of the monitoring pointer 6 is stored in the main control circuit through the monitoring sensor 62. On the other hand, due to external interference, the electronic count of the cumulative rotations of the monitoring pointer 6 recorded in the main control circuit may deviate from the actual number of cumulative rotations recorded by the counter. In the long run, this error will become larger and larger. In the application of the Internet of Things, this small flow error will affect the analysis of relevant information (information related to big data statistics, etc.). Therefore, the zeroing module is set: when the permanent magnetic sheet 4 rotates to the corresponding unit word wheel 11 in the positive position (or the non-positive position), the electronic count of the above-mentioned cumulative rotation is forced to be zeroed, thereby avoiding the infinite accumulation of such errors.

[0067] 5. Another improvement

[0068] In order to prevent the control circuit board 8 from getting wet and facilitate quick disassembly and assembly, the main control circuit, angle sensor 41 and monitoring sensor 62 are assembled in a "U"-shaped plastic shell cavity, which is fixed to the outside of the transparent cover 71 with a quick disassembly and assembly structure of building blocks (see Figure 1 ).

Claims

1. A structure of a direct reading counter for a mechanical meter, comprising a character wheel group (1) composed of a plurality of character wheels for displaying a high-order metering value in digital form, a gear transmission assembly (73) arranged under a transparent meter cover (71) made of non-magnetic material, and a driving wheel (732) driven by the flow of a metering fluid, wherein the driving wheel (732) is meshed with a driving gear (731) of the lowest order in the gear transmission assembly (73), each character wheel in the character wheel group (1) is connected together through a character wheel shaft, a carry coupling wheel is arranged between two adjacent character wheels, and a reading window (721) for reading the metering value of each character wheel is arranged on an upper clamping plate (72) at a position opposite to each character wheel in the character wheel group (1), wherein the reading window (721) is provided, wherein the metering value of each character wheel can be read, and the characteristics are as follows: The highest-order driving gear (731) in the gear transmission assembly (73) drives the rotation of the units character wheel (11) in the character wheel group (1) by meshing with the transmission intermediate wheel (2) and the middle drive coupling wheel (3) in turn. A permanent magnetic sheet (4) is provided at the center of the upper surface of the transmission intermediate wheel (2). A magnetic induction angle sensor (41) is provided at a position opposite to the permanent magnetic sheet (4) outside the transparent meter cover (71). The angle sensor (41) collects the position of the rotation angle of the permanent magnetic sheet (4) at a set frequency. The main control circuit of the meter stores the collected rotation angle of the permanent magnetic sheet (4) and the display value corresponding to the rotation angle and the units character wheel (11) in a storage unit of the main control circuit. A plurality of pointer disks (5) for displaying low-level meter values ​​in the form of rotating pointers (51) are provided under the transparent meter cover (71) and at a position opposite to the character wheel set (1); A monitoring pointer (6) is also provided below the transparent meter cover (71) and beside the pointer disk (5) to reflect whether the metered fluid is flowing; The main control circuit is also provided with a zeroing module for forcibly returning the accumulated electronic counted rotations of the monitoring pointer (6) to zero when the permanent magnetic sheet (4) rotates to a point where the count value of the units wheel (11) is at a plurality of set positions.

2. The structure of the direct reading counter for a mechanical meter according to claim 1, characterized in that: The transmission ratio between the intermediate transmission wheel (2), the middle drive coupling wheel (3) and the units wheel (11) is 1:1:

1.

3. The structure of the direct reading counter for a mechanical meter according to claim 2, characterized in that: Each pointer (51) in the pointer disk (5) is fixedly connected to a single-stage driving gear (731) in the gear transmission assembly (73).

4. The structure of the direct reading counter for a mechanical meter according to claim 3, characterized in that: The monitoring pointer (6) is fixedly connected to a monitoring gear (61) arranged under a transparent meter cover (71), and the monitoring gear (61) is meshed with the lowest-order driving gear (731); a monitoring sensor (62) is arranged at a position corresponding to the monitoring pointer (6) outside the transparent meter cover (71), and the monitoring sensor (62) stores the rotation state of the monitoring pointer (6) and the accumulated number of rotations of the monitoring pointer (6) in the storage unit.

5. The structure of the direct reading counter for a mechanical meter according to claim 4, characterized in that: The monitoring sensor (62) is an electromagnetic induction sensor, a magnetic induction sensor, a photoelectric sensor, a rheostat, a varactor or a travel switch.

6. The structure of the direct reading counter for a mechanical meter according to claim 5, characterized in that: The main control circuit, the angle sensor (41) and the monitoring sensor (62) are assembled in a U-shaped plastic shell cavity, and the plastic shell cavity is fixed to the outside of the transparent cover (71) with a building block-type quick disassembly structure.

7. The structure of the direct reading counter for a mechanical meter according to claim 6, characterized in that: A triggering program is provided in the main control circuit for starting the angle sensor (41) to collect the rotation position information of the permanent magnetic piece (4) at the set frequency according to the movement state of the monitoring pointer (6); when the cumulative number of rotations of the monitoring pointer (6) collected twice in the set frequency is the same, the angle sensor (41) will remain in a passive or dormant state.

8. A mechanical meter, comprising an impeller box (76), an impeller (77), a counter box (75) and a transparent meter cover (71) for sealing the meter case, the counter box (75) being sealed on the impeller box (76), an upper clamping plate (72) and a lower clamping plate (74) being arranged in the counter box (75), a gear transmission assembly (73) and a character wheel group (1) consisting of a plurality of character wheels for digitally displaying flow rate being arranged between the upper clamping plate (72) and the lower clamping plate (74), a carry coupling wheel being arranged between adjacent character wheels, the impeller (77) driving the lowest order driving gear (731) in the gear transmission assembly (73) to rotate through a driving wheel (732), characterized in that: A direct-reading counter structure for a mechanical meter according to any one of claims 1 to 7 is provided under the transparent meter cover (71).

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