JPH0556452B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention A-1 Field of Industrial Application This invention relates to a device for detecting that a water meter is incorrectly connected to a pipe in the opposite direction.

B-2 Prior Art The transmitter of a power-generating water meter is buried underground together with the metering section, and is connected to a receiver placed in a remote location by two electric wires. The electric pulse from the transmitter is a unit flow rate pulse of 1 m ³ /pulse.

In FIG. 13, reference numeral 1 denotes a metering section, in which an impeller 2 is rotatably supported in a fluid passage, and a reduction gear train 3
The pointer 4 is driven through the magnet, and the driving magnet 5 forming the magnetic coupling is rotated.

Water enters from the inlet 6, rotates the impeller 2, and flows downstream from the outlet 7. 8 is a dial plate, 9 is a glass, 10 is a transmitter attachment member fixed to the center of the glass 9, 11 is a nut for fixing the member 10 to the glass 9, and 12 is a nut 11 and a washer 13 that are attached to the glass 9. It is a leaf spring fixed in the center of.

The drive magnet 5 shown in this figure is magnetized into two poles in the diametrical direction, and the gear ratio of the reduction gear train 3 is determined so that it rotates once per 40 degrees of flow rate of water.

Reference numeral 14 denotes a transmitter, which has a case having a generally cylindrical shape as a whole, a lower end protrusion 15 of the case fits into the recess at the center of the transmitter mounting member 10, and the leaf spring 12 is inserted into a groove on the outer periphery of the case. By engaging,
A transmitter 14 is mounted and fixed on the upper part of the measuring section 1. Reference numeral 16 denotes a driven magnet fixed to a pinion 19 rotatably engaged with a shaft 18 fixed to the lower base plate 17 of the transmitter 14, forming a magnetic coupling with the drive magnet 5, and transmitting the rotation of the measuring section 1. It is transmitted to the container 14, which rotates at the speed of one revolution every 40 measurements.
The transmitter 14 is connected to a generator 20 and, as will be described later,
A tooth train that decelerates the rotation of the driven magnet 16, a reverse stop mechanism provided in this tooth train, and a spring that is wound up by the tooth train and stores energy.
It has an intermittent feeding mechanism that intermittently drives the generator 20 by discharging the energy of this spring every fixed rotation of the gear train, and connects two electric wires each connected at one end to the coil of the generator 20. Electric pulses (unit flow rate pulses) are transmitted to a receiver 24 in FIG. 150 by a transmission cord 23 having the same. The two electric wires of the transmission cord 23 are connected to a coil of a pulse motor (not shown) of the receiver 24 within the terminal box 25 of the receiver 24 . The pulse motor advances each time it receives the unit flow rate pulse, rotates the display number wheel, and the display number 26 indicates the integrated flow rate in m ³ units.

In the conventional transmitter 14 and receiver 24, as shown in FIG. The terminals 28 and 29 in the terminal box of the receiver 24 are removably connected to each other.

A-3 Problems to be Solved by the Present Invention In the conventional power-generating water meter described above, the measuring section 1 and the transmitter 14 are buried underground, so when checking the operation of the meter, the display on the receiver 24 is a unit flow rate pulse. I visually checked the progress each time. However,
Even if the water outlet downstream of the meter is fully opened and water flows at a rate of 1 to 2 m ³ /h, it will continue to flow for 30 minutes to 1 hour, and only one pulse will advance.
It takes too much time and is not practical.

The same applies to checking for fixed malfunctions of water meters, reverse connection of entrances and exits, etc. A stationary failure takes a long time, and in the case of a reverse connection at the entrance/exit, the transmitter's generator does not operate, so it is difficult to distinguish it from a stationary failure.

Conventionally, if there was such a concern, it was necessary to dig up the meter (measuring section and transmitter) and inspect it, which was inconvenient.

In view of the above, the present invention incorporates a sensor that detects the rotation of the driven magnet and generates an electric signal in a transmitter, and separately provides a checker for determining the waveform of this electric signal, thereby connecting the meter's entrance and exit in reverse. It is possible to make the discovery in a short time without having to dig up the meter.

B. Structure of the Invention B-1 Means for Solving Problems This invention provides a driven magnet that transmits the rotation of a drive magnet of a measuring section through magnetic coupling, a tooth train that decelerates the rotation of this driven magnet, and a gear train that decelerates the rotation of the driven magnet. A reversal prevention mechanism constituted by the engagement of a notched gear 56 attached to a gear shaft in a gear train and a clutch gear 57 loosely engaged with the gear shaft adjacent to the gear shaft, and a mainspring shaft.
A transmission having an intermittent feeding mechanism comprising a barrel attached to the shaft, the barrel engaging with a gear of a gear train, and a generator that is intermittently driven by the intermittent feeding mechanism to generate a unit flow rate pulse. In a remote indicating water meter comprising a receiver connected to a generator coil of the transmitter by two electric wires and installed at a remote location from the transmitter, the rotation of the driven magnet is detected. A sensor receives an electrical signal from this sensor, shapes this signal into a plurality of pulses for one rotation of the driven magnet, measures the interval between these pulses for each pulse, and measures the interval between two consecutive pulses. The present invention is characterized in that a checker is provided which determines that the new pulse interval is relatively larger than the previous old pulse interval and issues a reverse connection signal.

B-2 Effect When you fully open the water outlet downstream of the meter and let water flow, 1
When ~2 m ³ /h of water flows and the water meter is connected to the pipe in the correct orientation, the driven magnet rotates relatively quickly and continuously in the positive direction. With a gear ratio of one revolution every 40 at a flow rate of 1 to 2 m ³ /h, the driven magnet will make one revolution in 1.2 to 2.4 minutes. A sensor detects this rotation and continuously generates high-density pulses.

In addition, when the meter's inlet and outlet are reversely connected, the reverse point prevention mechanism installed in the gear train that meshes with the driven magnet is activated, so when the impeller is reversed by flowing water, the driven The magnet repeats reverse rotation, stop, and rapid forward rotation at the same speed as the driving magnet. Therefore, the intervals between the electrical signals generated in the sensor are such that short intervals and long intervals are adjacent to each other. By observing this with a checker, you can confirm that the entrance and exit are reversely connected.

B-3 Embodiment In FIG. 1, reference numeral 30 denotes a quadrupole magnet attached to the rotating shaft (pinion) of the driven magnet 16, and a sensor 31 is fixed to the lower base plate 17 by a mounting member 32 near the quadrupole magnet. In this embodiment, a magnetoresistive element is used as the sensor 31. 33 is an electric wire connected to the sensor 31, one of which is connected to one end of the one electric wire 22, and the other is connected to one end of a separately provided electric wire 34.

The transmission cord 35 has three electric wires 21, 22, 3
4 and are respectively connected to terminals 28, 29 and 36 in the terminal box 25 of the receiver 24 of FIGS. 2-5. Terminals 29 and 36 are electrically connected to female terminals 37 and 38, respectively, as shown in FIGS. 3 and 4. As shown in FIG. 2, plugs 41 and 42 provided at the ends of two electric wires 40 of a checker 39 are inserted into the female terminals 37 and 38 and electrically connected.

The checker 39 in FIG. 2 has two plugs 41,
42 into the female terminal of the terminal box of the receiver 24, it is electrically connected to the sensor 31 of the transmitter 14, and the electrical signal from the sensor 31 can be observed. A battery checker 44 that displays fluctuations in the signal from the sensor 31 as the driven magnet 16 rotates and displays the voltage of the built-in battery, an adjustment polyurethane 45 that adjusts the signal level of the sensor 31, and a meter that is reversed by reverse connection of the entrance and exit. a reversal indicator lamp 46 that lights up when the meter is running, a measurement start pushbutton switch 47, a battery check pushbutton switch 48, and a display 49 that displays the time since the start of measurement and the cumulative flow rate since the start of measurement. It is equipped with As shown in FIGS. 6 and 7, the transmitter 14 is provided with a two-pole driven magnet 16 fixed to a pinion 19 and another four-pole magnet 30, and this pinion is connected to the shaft 18 in FIG. It is rotatably engaged. 50 is a second gear rotatable together with the second shaft 51, 52 is a second pinion, 53 is a third gear rotatable together with the third shaft 54 and third pinion 55, and 56 is a notch attached to the second shaft 51. Together with the clutch gear 57 which is a gear and is loosely engaged with the third shaft 54, the reverse rotation prevention mechanism 70 is constituted. 58 is a fourth wheel, 59 is a fifth wheel, 60 is a Zenmai shaft, and 61 is a gear attached to the shaft of the generator 20, which meshes with a pinion provided on the barrel of Zenmai 62.
The forward rotation of the driven magnet is decelerated by a reduction gear train 63 consisting of the second to fifth wheels, and winds up the spring 62 of the full-speed shaft 60 . The fifth wheel 59 and the main barrel 60a of the full shaft 60 are equipped with a well-known intermittent feed mechanism 7.
1 is provided. The driven magnet 16, the reduction gear train 63, the reverse stop mechanism 70, the spring (zentai) 62, the intermittent feed mechanism 71, and the generator 20 are completely the same as those in the prior art shown in FIG.

Now, when the water meter is operating normally, when the downstream port of the water meter is fully opened and a flow rate of 1 to 2 m ³ /h is allowed to flow, the driven magnet 16 rotates following the driving magnet. Assuming that the drive magnet 5 rotates once every 40 degrees as in the prior art shown in FIG. 11, the drive magnet 5 rotates once every 2.4 minutes to 1.2 minutes. magnet 30
Since there are four poles, the resistance value of the sensor 31 changes four times during one rotation of the drive magnet 5, as shown in FIG. Since one fluctuation corresponds to 10 flow rates, high-density electric pulses are applied to the checker 3 due to changes in the resistance value of the magnetoresistive element that constitutes the sensor.
By integrating with 9, the integrated flow rate can be displayed with a resolution of 10.

When the metering part 1 of the water meter has the inlet and outlet reversely connected, the impeller 2 is reversed and the drive magnet 5 is continuously reversed. The driven magnet 16 tries to follow the driving magnet 5 and rotate in reverse, but is prevented from rotating in the reverse direction continuously because it is blocked by the reverse rotation prevention mechanism 70.

The reverse prevention mechanism 70 is composed of a notched gear 56 attached to the second shaft and a clutch gear 57 loosely engaged with the third shaft.As shown in FIG. 9A, the notched gear 56 has 10 teeth. , with one side of each tooth cut out. Further, the clutch gear 57 consists of six low teeth and four high teeth.

When the impeller of the metering section 1 rotates in reverse (that is, when the inlet and outlet are reversely connected), the driving magnet 5 rotates in the reverse clockwise direction as shown in FIG. 9A, and the driven magnet follows this and rotates in the reverse direction. shall be. Also, the notched gear 56 tries to rotate counterclockwise as shown by the dashed arrow in the figure due to the force of the spring (full swing) 62, but as shown in FIG.
a is engaged with the teeth 57a of the clutch gear 57 to prevent reverse rotation, so the driven magnet 16 is stopped in the state shown in FIG.

In FIG. 9, for convenience of explanation, the driving magnet 5 is shown as an outer circle, and the driven magnet 16 is shown as an inner circle.

Figure B shows how the driving magnet 5 is further reversed by 45 degrees from this state, but the driven magnet remains in the same state as shown in Figure A due to the action of the reversal prevention mechanism. The drive magnet further rotates, and from the state of A in the same figure it becomes 180 degrees.
degree (1/2 rotation), it becomes the state shown in figure C, and after this state, the driving magnet 5 and the driven magnet 1
6 are repelled and attracted to each other, and the driven magnet 16 is
Rotate forward 180 degrees (1/2 turn) to the position shown. Therefore, the notched gear 56 also rotates by two teeth clockwise (positive direction), and the teeth 56a move to the illustrated position. From this FIG. 9D, it can be seen that the driving magnet 5 is further 180
The driven magnet 16 is rotated counterclockwise (1/2 turn) until it returns to the state shown in A in the same figure.
When the driven magnet 16 rotates in the opposite direction and reaches the state shown in FIG. In this way, during the 1/2 rotation of the drive magnet from D to A in FIG. 9, the driven magnet follows the drive magnet and rotates in the opposite direction, and during the approximately half rotation from A to C in the same figure,
The driven magnet stops, and the driven magnet instantaneously rotates half a turn in the normal direction in the state shown in FIG.

Therefore, when the meter is reversed due to the reverse connection of the entrance and exit, the driven magnet 16 follows the driving magnet and performs a half-turn reversal → a stop during a half-rotation of the driving magnet → an instantaneous half-rotation forward rotation. repeat. At this time,
The resistance of the sensor 31 changes as shown in Fig. 10, and unlike Fig. 8 when the meter is operating normally, the resistance value changes intermittently, so the checker 39 determines the difference and the meter detects the reverse connection of the entrance and exit. You can know that.

Note that when the checker 39 presses the measurement start push button switch 47, the display of time and integrated flow rate is reset to zero.

Next, the reverse rotation detection circuit of the checker will be explained.

FIG. 11 is a block diagram of a checker reverse rotation detection circuit, and FIG. 12 is a diagram explaining its operation.

The electrical signal from the sensor 31 is transmitted to the checker 39 as a resistance value change signal of the magnetoresistive element, and is shaped by the pulse shaping circuit 72 into a plurality of pulses per rotation of the driven magnet. As shown in FIG. 12, the signal of the resistance change of the sensor is shaped into four rectangular pulses per revolution of the driven magnet at the output of the pulse shaping circuit. This pulse is input to the C input of the D flip-flop 73 whose D input is at a high level and to the rising edge detection circuit 74. The rising edge detection circuit 74 outputs a rectangular pulse with a very short duration at the rising edge of the output pulse of the pulse shaping circuit 72, and this short pulse is connected to the latch signal input of the latch circuit 75 and one of the two-input OR circuits 76. and the input of the delay circuit 77.

The output of the delay circuit 77 is input to the reset terminal R of the counter A78. D flip-flop 73
The output of is applied to the other input of the two-input OR circuit 76 and the input of the delay circuit 79, and the output of the delay circuit 79 is input to the reset terminal R of the latch circuit 75 and the reset terminal R of the holding circuit 80. Ru. When the reset input applied to the reset terminal R of the latch circuit 75 is at a high level, all outputs are at a high level of "1". In other words, it is the maximum binary number that can be expressed at the output terminal.

The output (binary value) of the counter A78 is input to this latch circuit 75, and when the reset terminal R is at a low level, the value (count value) of the counter A78 at that moment is stored at the rising edge of the latch signal input. The stored value is output to the A input of the comparison circuit 81.

A clock signal from a clock oscillator 82 is input to the clock input terminal C of the counter A78. This clock signal is also applied to the clock input terminal C of the counter B84 via the 1/2 frequency divider circuit 83. The output of the 2-input OR circuit 76 is the counter B8
It is applied to the reset terminal (R) of No.4. Comparison circuit 81
The output (count value) of counter B is input to input B of , and "input B" is input from the binary number of "input A".
When the binary number of is large, the output is high level.
This output is applied to the set input S of the holding circuit 80 and held, and becomes a reverse rotation detection signal.

The signal from the sensor 31 is shaped by the pulse shaping circuit 72, and at the rising edge of the pulse, the count value of the counter A78 is stored in the latch circuit 75, and then the signal is sent for a short time of the delay time of the delay circuit 77. Counter A78 is reset. In other words, the latch circuit 75 always stores the latest (immediate) pulse interval.

Counter B84, like counter A, is reset at the rising edge of the pulse, but since the clock signal to be counted is frequency-divided by 1/2, the count value is 1/2 that of counter A.

If a power-generating water meter with the structure shown in Figure 1 in the above explanation is connected to the piping in the opposite direction, when the downstream port of the meter is opened and water flows at a constant flow rate, the sensor 3
The resistance value of the magnetoresistive element constituting 1 is shown in Figure 12A.
It changes like this. (When the meter is connected in the correct direction rather than in the opposite direction, it changes like a broken line.)
A pulse obtained by shaping this resistance change signal by the pulse shaping circuit 72 is shown in FIG.

A start signal is applied to the reset terminal R of the D flip-flop 73, and changes from high level to low level at the start of measurement. When this signal is at a high level, the output of the D flip-flop 73 is at a high level, so the output of the OR circuit 76 is also at a high level and the counter B84 is in a reset state, and its output is the minimum number of 0s. Furthermore, since the reset terminal R of the latch circuit 75 is at a high level, all the output terminals of the latch circuit 75 are "1", which is the maximum number, as described above.

Therefore, the reverse rotation detection signal output from the holding circuit 80 is at a low level. Even if the start signal becomes low level at t ₁ in Fig. 12 and measurement is started,
The output of the D flip-flop 73 remains high until t ₂ when _the first pulse input is applied, at which time the output goes low. At this time, since the fall timing of the reset input is delayed by the delay circuit 79 compared to the rise of the latch input of the latch circuit 75, the output of the latch circuit 75 does not change and remains at the maximum number. At _t3 , the number of clock pulses corresponding to pulse interval a of FIG. 12 is stored and held in latch circuit 75 from counter A78. At _t4 , the count value of counter B84 exceeds the number of clock pulses corresponding to a, and the relationship 2a<b is established between adjacent pulse intervals a and b,
Input B of comparison circuit 81 becomes larger than input A,
The output becomes high level, this output is held by the holding circuit 80, a high level reverse rotation detection signal is output, and the reverse rotation indicator lamp 46 shown in FIG. 2 is lit.

The pulse interval when the driven magnet rapidly rotates forward while the driving magnet is in reverse rotation is the interval between t ₅ and t ₆ in Fig. 12, which is sufficiently smaller than the normal interval between t ₂ and t ₃ . If the measurement starts during the "stop" period of the driven magnet, the reversal detection signal becomes high level at _t7 , a little after this "rapid forward rotation" and the transition to "reverse rotation". As described above, in the embodiment, there is a point in which reverse rotation can be detected at two locations for one rotation of the drive magnet.

In this embodiment, the clock signal of clock oscillator 82 is sent directly to counter A78, and to counter B84.
is input through the 1/2 frequency divider circuit 83, and the comparator circuit 7
5, the condition of A<B is determined and the holding circuit 80 outputs a reverse rotation signal, so that when the pulse interval b becomes twice or more than the immediately preceding pulse interval a in FIG. 12, a reverse rotation signal is output. However, even if the dividing ratio of the frequency dividing circuit 83 is set appropriately so that a reverse signal is output when the pulse interval b becomes K times or more the immediately preceding pulse interval a for a value K of 1 or more, the meter Can detect reversal and know reverse connection.

In the above embodiment, the magnet 30 that acts on the magnetic resistance element 31 is a four-pole magnet separate from the driven magnet 16, but as shown in FIG. It is also possible to use a magnetic field as a pole so that the resistance value of the magnetoresistive element 31 changes with this magnetic field.

C. Effects of the Invention In this invention, the rotation of the driven magnet, which rotates relatively quickly, is detected by the sensor 31 such as a magnetoresistive element, and attention is paid to the fact that the interval between the electric signals generated by the sensor 31 when the meter is reversely connected is unique. , this is detected by the checker to determine the reverse connection, so
This has the effect of making it possible to automatically check the reverse connection of the meter in a short period of time.

[Brief explanation of the drawing]

Figures 1 to 7 show embodiments of the present invention, with Figure 1 being a longitudinal section of the measuring section and transmitter, Figure 2 being a front view of the receiver and checker, and Figures 3 and 4 showing the receiver. Figure 5 is an electrical circuit diagram, Figure 6 is a vertical cross-section of the transmitter gear train, and Figure 7 is a diagram around the driven magnet, with A being a front view and B being a vertical cross-section. Figures C is a bottom view, Figures 8 and 10 are diagrams showing changes in the resistance value of the sensor (magnetic resistance element), Figure 9 is a diagram explaining the operation of the reverse stop mechanism, and Figure 11 is this diagram. A block diagram of a checker according to an embodiment of the invention, FIG. 12 is a diagram explaining the operation, FIGS. 13 to 15 are related to the prior art, FIG. 13 is a vertical cross section of the measuring section and transmitter, and FIG. 14 15 is a front view of the receiver, FIG. 15 is an electric circuit diagram, FIG. 16 is a diagram showing the area around the driven magnet of another embodiment, A is a longitudinal sectional view, and B is a bottom view. DESCRIPTION OF SYMBOLS 1... Measuring part, 5... Drive magnet, 14... Transmitter, 16... Driven magnet, 20... Generator, 24...
...Receiver, 30...Another magnet, 31...Sensor,
39...Checker, 63...Tooth train, 64...Spring, 70...Return prevention mechanism, 71...Intermittent feed mechanism.

Claims (1)

[Claims] 1. A driven magnet that transmits the rotation of the drive magnet of the measuring section through magnetic coupling, a gear train that decelerates the rotation of this driven magnet, a notched gear 56 attached to a gear shaft in this gear train, and the gear. A reverse prevention mechanism is constructed by engaging a clutch gear 57 that is loosely engaged with a gear shaft adjacent to the shaft, and a mainspring shaft, a barrel attached to the shaft, and a gear of a gear train. A transmitter has an intermittent feed mechanism consisting of a barrel, a generator that is intermittently driven by the intermittent feed mechanism to generate a unit flow rate pulse, and is connected to the coil of the generator of this transmitter with two electric wires. In a remote indicating water meter consisting of a transmitter and a receiver installed at a remote location, a sensor detects the rotation of the driven magnet, receives an electrical signal from this sensor, and sends this signal to one of the driven magnets. shaping the rotation into a plurality of pulses, measuring the interval between the pulses pulse by pulse, and determining that for two successive pulse intervals, the later new pulse interval is relatively larger than the previous older pulse interval; A water meter inspection device equipped with a checker that outputs a reverse connection signal.