JP7635451B2 - Bucket Type Flow Meter - Google Patents

Description

An embodiment of the present invention relates to a bucket type flow meter.

The basic principle of a bucket flowmeter is that liquid flowing in from the inlet is received by a bucket (tipping bucket) divided into two parts, left and right, and when liquid accumulates, the bucket starts to tip over on the side where the liquid has accumulated, and the other side repeats this process to receive the liquid. The tipping motion is detected by a magnetic or position sensor, output as a pulse signal, and the flow rate is calculated from the number of tippings and the amount of liquid discharged per tipping.

Because the liquid is stored in the bucket once, this method is suitable for measuring minute flow rates, but various factors can cause errors. For this reason, conventionally, the accuracy of flow rate measurement has been ensured by creating a correlation function between the flow rate and the number of tippings based on the correlation between the amount of liquid drained per tipping of the bucket and the flow rate, and then calculating the flow rate from the number of tippings, or by providing a lid on the bucket that opens only when the bucket tips to prevent spillage, or by correcting the amount of spillage from the tipping interval, bucket capacity, and a constant calculated from testing.

JP 2010-237056 A

Bucket flow meters are used as rain gauges for general industry as well as to detect leaks in nuclear power plants, and there are currently plans to review the measurement accuracy in low flow ranges. As the accuracy guaranteed by conventional methods is not reliable enough, further improvements in measurement accuracy are required. In addition, since the flow rate is calculated by sampling the number of times the bucket tips over, and is not monitored continuously, it takes time to update the measured flow rate.

The embodiment of the present invention has been made in consideration of the above circumstances, and aims to provide a bucket-type flowmeter that can improve the measurement accuracy of the flow rate in a specific flow rate range of a liquid.

A bucket type flowmeter in an embodiment of the present invention is characterized in having a pair of measure portions formed on either side of a fulcrum and rotatable about the fulcrum, a bucket that tips over to drain liquid when liquid flows into the measure portion from an inlet portion and accumulates a predetermined amount, an impact sensor that detects the impact caused when the bucket tips over, and a flow rate calculation means that calculates the flow rate of the liquid based on the impact force determined from the detection signal of the impact sensor and a flow rate/impact force correlation function that defines the relationship between the flow rate of the liquid and the impact force.

According to an embodiment of the present invention, it is possible to improve the accuracy of measuring the flow rate of a liquid in a specific flow rate range.

FIG. 1 is a front cross-sectional view showing a bucket type flowmeter according to a first embodiment. FIG. 2 is a perspective view showing a bucket and a detection unit of the bucket type flowmeter of FIG. 1 . 2 is an operational diagram illustrating an operating state of the bucket flowmeter of FIG. 1 . FIG. 2 is a block diagram showing a flow of data processing in the bucket type flowmeter of FIG. 1 . 4 is a graph showing a correlation function between the flow rate of water to be measured and the displacement amount per one overturning of the bucket in the bucket type flowmeter of FIG. 1 . 5 is a graph showing a correlation function between the flow rate and the number of falls used in the flow rate calculation circuit of FIG. 4 . 4 is a graph showing the relationship between the flow rate characteristics and adjustment of the displacement amount per bucket overturning in the bucket type flowmeter of FIG. 1 . FIG. 4 is a diagram showing an example of a projection adjustment mechanism. FIG. 11 is a block diagram showing a flow of data processing in a bucket type flowmeter according to a second embodiment. 10 is a time chart illustrating a fall time interval detected by the timer in FIG. 9 . 10 is a graph showing a flow rate/fall time interval correlation function used in the flow rate calculation circuit of FIG. 9 . FIG. 11 is a block diagram showing a flow of data processing in a bucket type flowmeter according to a third embodiment. 13 is a time chart for explaining the remaining time and the overturning time interval required for the remaining amount calculation circuit of FIG. 12 to calculate the remaining amount of water in the bucket. FIG. 13 is a block diagram showing a flow of data processing in a bucket type flowmeter according to a fourth embodiment. 15A and 15B are graphs showing a flow rate vs. fall count correlation function determined by the determination circuit of FIG. 14, in which (A) shows the same function in the entire flow rate region and (B) shows the same function in a specific flow rate region. 15A and 15B are graphs showing a flow rate vs. fall time interval correlation function determined by the determination circuit of FIG. 14, in which (A) shows the same function in the entire flow rate region and (B) shows the same function in a specific flow rate region. FIG. 13 is a block diagram showing a flow of data processing in a bucket type flowmeter according to a fifth embodiment. 18 is a time chart showing a sensor signal output from the acceleration sensor of FIG. 17; 18 is a graph showing a flow rate/impact force correlation function used in the flow rate calculation circuit of FIG. 17 . FIG. 13 is a block diagram showing a flow of data processing in a bucket type flowmeter according to a sixth embodiment. 21 is a time chart for explaining the operation time of a reed switch for the overturning direction confirmation circuit of FIG. 20 to confirm the overturning direction of the bucket. 21 is a time chart for explaining the operation time of the reed switch input to the flow rate calculation circuit of FIG. 20 . 21 is a graph showing a flow rate/operation time correlation function used in the flow rate calculation circuit of FIG. 20 . FIG. 23 is a block diagram showing the flow of data processing in a bucket type flowmeter according to a seventh embodiment. 25A and 25B are graphs showing the flow rate-impact force correlation function determined by the determination circuit of FIG. 24, in which (a) shows the same function in the entire flow rate range and (b) shows the same function in a specific flow rate range. 25A and 25B are graphs showing the flow rate-operation time correlation function determined by the determination circuit of FIG. 24, in which (a) shows the same function in the entire flow rate region and (b) shows the same function in a specific flow rate region. FIG. 23 is a block diagram mainly showing the flow of data processing in a bucket type flowmeter according to an eighth embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[A] First embodiment (FIGS. 1 to 8)
Fig. 1 is a front cross-sectional view showing a bucket type flowmeter according to a first embodiment. Fig. 2 is a perspective view showing a bucket and a detection unit of the bucket type flowmeter of Fig. 1. The bucket type flowmeter 10 shown in Fig. 1 and Fig. 2 measures the flow rate of water as a liquid flowing through a water supply pipe 20, and includes a bucket 11, a regulating unit 12 as a regulating means, a detection unit 13 as a detecting means, an integrating counter 14 as an integrating counting means, a flow rate calculation circuit 15 as a flow rate calculation means, and a case 16, as shown in Fig. 1, Fig. 2, and Fig. 4.

The case 16 is composed of a generally cylindrical case body 16A and cover plates 16B (only one is shown in FIG. 1) fixed to both ends. An inlet 17 protrudes inward from the top of the case body 16A, and the downstream end of a water supply pipe 20 is connected to this inlet 17. Water supplied from the water supply pipe 20 flows (down) from the inlet 17 into the bucket 11's basin 18 or 19 (both described below). In addition, the upstream end of a drainage pipe 21 is connected to the bottom of the case body 16A.

Seat plates 22 (only one is shown in FIG. 1) are fixed to both cover plates 16B of the case 16 using bolts or the like. One of the seat plates 22 pivots to one of the seat plates 22, and the other fulcrum 23B of the bucket 11 pivots to a mounting plate 24 fixed to the other seat plate 22 (not shown).

This bucket 11 has a pair of manholes 18, 19 formed on the left and right sides of the coaxial fulcrums 23A and 23B. Water flows into these manholes 18 or 19 from the inlet 17 and is stored in a predetermined amount. Here, manholes 18 and 19 are set to the same capacity. When a predetermined amount of water is stored in manhole 18 or 19, the bucket 11 rotates around fulcrums 23A and 23B due to the action of gravity on the stored water, and tips over, discharging the stored water. The water discharged from the bucket 11 flows down into the case body 16A of the case 16, and is then led to the drainage pipe 21.

The regulating unit 12 regulates the tipping stop position of the bucket 11, and is composed of length-adjustable ferrules 25 and 26 and stoppers 27 and 28. The ferrule 25 is attached to the bottom of the box section 18 of the bucket 11, and the ferrule 26 is attached to the bottom of the box section 19. The stoppers 27 and 28 are also fixed to the seat board 22. The ferrule 25 abuts against the stopper 27, and the ferrule 26 abuts against the stopper 28, regulating the left and right tipping stop positions of the bucket 11.

As shown in FIG. 3, when water flows into the manhole 19 of the bucket 11 from the inlet 17 and a predetermined amount is accumulated, the bucket 11 rotates clockwise around the fulcrums 23A and 23B in FIG. 3 and tips over, the ferrule 26 abuts against the stopper 28, stopping the tipping motion and draining water from the manhole 19 of the bucket 11. At this time, the manhole 18 of the bucket 11 is positioned opposite the inlet 17, so water then flows from the inlet 17 into the manhole 18.

When a predetermined amount of water has been stored in the manhole 18, the bucket 11 rotates counterclockwise around the fulcrums 23A and 23B in FIG. 3 and tips over, the ferrule 25 abuts against the stopper 27, stopping the tipping motion and draining water from the manhole 18 of the bucket 11. In this way, the bucket 11 alternately stores water in the manholes 18 and 19, and tips over to drain the water.

The detection unit 13 shown in FIG. 2 detects the tipping over of the bucket 11, and is composed of a magnet 30 installed near the fulcrums 23A and 23B of the bucket 11, a reed switch 31 that turns on when the magnet 30 approaches and turns off when the magnet 30 moves away, and a detection circuit 32 connected to the reed switch 31.

The reed switch 31 is installed on the mounting plate 24 and positioned below the fulcrums 23A and 23B of the bucket 11. Therefore, when the bucket 11 tips over, the magnet 30 also moves with the bucket 11, and the magnetic force of this moving magnet 30 causes the reed switch 31 to switch from OFF to ON and output a pulse signal. One pulse of this pulse signal is output every time the bucket 11 tips over. The pulse signal from the reed switch 31 is filtered out of, for example, noise by the detection circuit 32, and is then output to the accumulating counter 14 shown in FIG. 4.

The accumulating counter 14 counts and accumulates the pulse signals from the detection circuit 32 of the detection unit 13 per unit time (for example, per minute) to count the number N of times the bucket 11 tips over. Here, as shown in FIG. 5, the amount of discharge per tipping of the bucket 11 (hereinafter referred to as the "amount of discharge per tipping") increases mainly when the flow rate of water flowing from the inlet 17 into the manhole 18 or 19 of the bucket 11 increases. Therefore, taking into consideration the flow rate/one-tipping discharge correlation function shown in FIG. 5, which defines the relationship between the flow rate of water flowing from the inlet 17 into the manhole 18 or 19 of the bucket 11 and the amount of discharge per tipping of the bucket 11, a flow rate/number-of-tipping correlation function that defines the relationship between the flow rate of water flowing from the inlet 17 into the manhole 18 or 19 of the bucket 11 and the number of times the bucket 11 tips over is calculated in advance as shown in FIG. 6.

The flow rate calculation circuit 15 uses the number of overturns as a parameter for flow rate calculation, and calculates the water flow rate based on this parameter for flow rate calculation. In other words, the flow rate calculation circuit 15 calculates the flow rate of water flowing into the bucket 11 from the inlet 17, i.e., the flow rate of water flowing through the water supply pipe 20, from the number of overturns N of the bucket 11 counted by the integrating counter 14, based on the above-mentioned flow rate/number of overturns correlation function (Figure 6), and outputs this to the outside as a flow rate signal.

As mentioned above, when the flow rate of water flowing into the bucket 11 from the inlet 17 increases, the one-tipping discharge amount of the bucket 11 mainly increases (FIG. 5). Also, when the length of the ferrules 25 and 26 of the regulating unit 12 shown in FIG. 1 is adjusted to be longer and the tipping stop position of the bucket 11 is set higher (raised), the one-tipping discharge amount of the bucket 11 decreases as shown in FIG. 7. Therefore, the tipping stop position of the bucket 11 is set by adjusting the length of the ferrules 25 and 26 (for example, solid line in FIG. 7) so that the change in the one-tipping discharge amount of the bucket 11 with respect to the change in the flow rate in the specific flow rate range Y near the set value X for alarm generation (FIG. 7) becomes small (i.e., the one-tipping discharge amount becomes approximately constant). Here, the specific flow rate range Y includes the set value X, for example, and is set as a range of 20% or narrower than the entire flow rate range.

As described above, the flow rate of water flowing from the inlet 17 into the bucket 11 is calculated by the flow rate/number of overturns correlation function (see FIG. 6) calculated from the flow rate/one overturn displacement correlation function (see FIG. 5) when the length of the ferrules 25 and 26 is adjusted, based on the number of overturns of the bucket 11, by the flow rate calculation circuit 15.

The length adjustment of the ferrules 25 and 26 in the regulating unit 12 may be performed manually, or may be automatically adjusted by an external signal i using the ferrule adjustment mechanism 33 shown in FIG. 8. For example, a movable bar 35 is disposed inside a cylindrical body 24 that can be attached to the bucket 11, and the ferrule 25 or 26 is disposed at the lower end of the movable bar 35. A magnet (electromagnet or permanent magnet) 36 is disposed at the upper end of the movable bar 35 disposed inside the cylindrical body 34. An electromagnet 37 is disposed at the upper end of the cylindrical body 34, and the magnetic force of the electromagnet 37 is changed by an external signal i, so that the movable bar 35 moves via the magnet 36, and the positions of the ferrules 25 and 26 are adjusted.

As configured as above, the first embodiment provides the following advantages (1) and (2).
(1) The length of the ferrules 25 and 26 of the regulating unit 12 is adjusted to set the tipping stop position of the bucket 11 so that the change in the one-overturn displacement of the bucket 11 is small relative to the change in the flow rate in the specific flow rate range Y of the water flowing into the bucket 11 from the inlet portion 17 (i.e., the one-overturn displacement becomes approximately constant), and the flow rate calculation means 15 calculates and measures the flow rate from the number of overturns N counted by the accumulating counter 14 based on the flow rate/number-of-overturns correlation function calculated from the flow rate/one-overturn displacement correlation function at this time. This makes it possible to improve the measurement accuracy of the water flow rate in the specific flow rate range Y, and as a result, makes it possible to prevent erroneous alarms from being issued.

(2) The length of the ferrules 25 and 26 (the tipping stop position of the bucket 11) is adjusted by an external signal i using the ferrule adjustment mechanism 33. Therefore, even if the bucket flowmeter 10 is installed in a location where workers cannot easily access it, the amount of water displaced per tipping of the bucket 11 can be easily changed by using the ferrule adjustment mechanism 33. This improves the accuracy of measuring the water flow rate by the bucket 11.

[B] Second embodiment (FIGS. 9 to 11)
9 is a block diagram showing the flow of data processing in a bucket type flowmeter according to the second embodiment. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be simplified or omitted.

The bucket flowmeter 40 of the second embodiment differs from the first embodiment in that, instead of the integrating counter 14 and the flow calculation circuit 15, it has a timer 41 as a timer means for detecting the overturning time interval of the bucket 11, a memory circuit 42 for storing a plurality of overturning time intervals, an averaging circuit 43 as an average calculation means for calculating an average value from a plurality of overturning time intervals, and a flow calculation circuit 44 as a flow calculation means for calculating the flow rate of water flowing into the bucket 11 from the overturning time interval or the average value.

In other words, the timer 41 detects the tipping time interval T per tipping from one tipping of the bucket 11 to the next tipping from the time interval between the rise times S... of adjacent pulse signals PS (Figure 10) output from the detection circuit 32 of the detection unit 13.

The memory circuit 42 holds the tipping time interval T of the bucket 11 output from the timer 41. The flow rate of water flowing into the bucket 11 may fluctuate instantaneously, causing the tipping time interval of the pulse signal PS to change to a value T1 different from T, as shown in FIG. 10. Taking this into consideration, the averaging circuit 43 calculates an average value by averaging the multiple tipping time intervals T, T1, ... of the bucket 11 held in the memory circuit 42.

The flow rate calculation circuit 44 uses the overturning time interval as a flow rate calculation parameter, and also uses the average value of the overturning time interval calculated by the averaging circuit 43 as a flow rate calculation parameter, and calculates the water flow rate based on these flow rate calculation parameters. That is, the flow rate calculation circuit 44 first has a flow rate/overturning time interval correlation function shown in FIG. 11 that defines the relationship between the flow rate of water flowing into the bucket 11 from the inlet 17 and the overturning time interval T of the bucket 11. Next, based on this flow rate/overturning time interval correlation function, the flow rate calculation circuit 44 calculates the flow rate Va of water flowing into the bucket 11 from the overturning time interval Ta of the bucket 11 output from the timer 41, and calculates the flow rate Vb of water flowing into the bucket 11 from the average value Tb of the overturning time interval T of the bucket 11 output from the averaging circuit 43.

As configured as above, the second embodiment provides the following advantages (3) and (4).
(3) The timer 41 detects the overturning time interval T per overturning of the bucket 11, and the flow rate calculation circuit 44 calculates the flow rate of water flowing into the bucket 11 using this overturning time interval T per overturning, so that the flow rate can be measured each time the bucket 11 overturns. As a result, the flow rate measurement information can be updated each time the bucket 11 overturns, rather than at regular time intervals as in the first embodiment.

(4) When the flow rate calculation circuit 44 calculates the flow rate from the average value of multiple overturning time intervals T calculated by the averaging circuit 43, the flow rate of water flowing into the bucket 11 can be measured stably and accurately regardless of momentary fluctuations in the flow rate of water flowing into the bucket 11.

[C] Third embodiment (FIGS. 12 and 13)
Fig. 12 is a block diagram showing the flow of data processing in a bucket type flowmeter according to the third embodiment. Fig. 13 is a time chart showing the relationship between the remaining time M required for the remaining amount calculation circuit of Fig. 12 to calculate the remaining amount of water in the bucket and the overturning time interval T. In this third embodiment, the same parts as those in the first and second embodiments are given the same reference numerals as those in the first and second embodiments, and the description thereof will be simplified or omitted.

The bucket type flowmeter 50 of the third embodiment differs from the first and second embodiments in that the flow calculation circuit 51 as a flow calculation means selectively or simultaneously executes a first function of calculating the flow rate of water flowing into the bucket 11 using the number of times N the bucket 11 has overturned, counted by the integrating counter 14, and a flow rate/number of overturns correlation function, and a second function of calculating the flow rate of water flowing into the bucket 11 using the overturning time interval T of the bucket 11 detected by the timer 41 and a flow rate/overturning time interval correlation function, and has a remaining time detection circuit 52 as a remaining time detection means, a remaining amount calculation circuit 53 as a remaining amount calculation means, and a flow rate addition/subtraction circuit 54 as a correction means.

The remaining time detection circuit 52 uses the pulse signals from the reed switch 31 and the detection circuit 32 to detect the remaining time M from the start time S of the last tipping of the bucket 11 within one cycle in which the integrating counter 14 counts the number of times N the bucket 11 tips over to the end time Se of the one cycle.

The remaining amount calculation circuit 53 first determines the ratio (M/T) between the remaining time M detected by the remaining time detection circuit 52 and the overturning time interval T of the bucket 11 detected by the timer 41. Next, the remaining amount calculation circuit 53 multiplies the amount of water displaced by one overturning of the bucket 11 at the time when the flow rate calculation circuit 51 calculates the flow rate by the ratio (M/T) to calculate the amount of water remaining in the bucket 11 without being discharged from the bucket 11 during one cycle.

The flow rate addition/subtraction circuit 54 uses the remaining amount of water calculated by the remaining amount calculation circuit 53 to correct the water flow rate calculated by the flow rate calculation circuit 51 in the first function. For example, if water remains in the bucket 11 during the one cycle, this remaining amount (remaining amount) is added to the flow rate calculated by the flow rate calculation means 51 to correct the flow rate. In addition, the amount of water remaining in the bucket 11 during the previous cycle is added to the water flow rate calculated by the flow rate calculation circuit 51 during the next cycle following the one cycle, so this is subtracted to correct the flow rate. Note that even when the flow rate calculation circuit 51 selects only the first function, the timer 41 is in an operating state.

As configured as above, the third embodiment achieves the same effects as the effects (1) to (4) of the first and second embodiments, and also achieves the following effect (5).
(5) The remaining amount calculation circuit 53 calculates the amount of water remaining in the bucket 11 during one cycle for counting the number of times N the bucket 11 overturns, and the flow rate addition/subtraction circuit 54 uses this remaining amount to correct the flow rate calculated by the first function of the flow rate calculation circuit 51. This makes it possible to improve the measurement accuracy of the flow rate calculated using the number of times N the bucket 11 overturns.

[D] Fourth embodiment (FIGS. 14 to 16)
14 is a block diagram showing the flow of data processing in a bucket type flowmeter according to the fourth embodiment. In the fourth embodiment, the same parts as those in the first to third embodiments are denoted by the same reference numerals as those in the first to third embodiments, and the description thereof will be simplified or omitted.

The bucket-type flowmeter 60 of the fourth embodiment differs from the first to third embodiments in that it provides two types of functions for the correlation function between the flow calculation parameters and the flow rate (i.e., the flow rate/tipping count correlation function or the flow rate/tipping time interval correlation function), one for the entire flow rate region (Fig. 15(A) and Fig. 16(A)) and one for a specific flow rate region (Fig. 15(B) and Fig. 16(B)), and has a determination circuit 61 as a determination means for determining which of the two types of functions the flow rate calculation circuit 51 should use.

Here, the specific flow rate range is, for example, the specific flow rate range Y near the set value X (Fig. 15(B) and Fig. 16(B)) that generates an alarm. The total flow rate range is a wide range of flow rate that includes the specific flow rate range Y. In particular, the functions of the specific flow rate range Y (the correlation function between the flow rate and the number of falls, and the correlation function between the flow rate and the time interval between falls) have a denser number of plots than the correlation functions of the total flow rate range, and are closer to the actual characteristics measured in advance.

The specific flow rate range Y in the flow rate/tipping count correlation function corresponds to the range of the number of times N the bucket 11 tips over, n1 to n2. Also, the specific flow rate range Y in the flow rate/tipping time interval correlation function corresponds to the range of the tipping time interval T of the bucket 11, t1 to t2.

When the flow rate calculation circuit 51 calculates the flow rate of water flowing into the bucket 11, if the value of the flow rate calculation parameter input to the flow rate calculation means 51, i.e., the value of the number of times N the bucket 11 has overturned input from the accumulating counter 14 to the flow rate calculation circuit 51, is in the range of n1 to n2, the judgment circuit 61 judges that the flow rate calculation circuit 51 should use the flow rate/number of times overturned correlation function for the specific flow rate range Y shown in FIG. 15(B). Also, if the value of the number of times N the bucket 11 has overturned input from the accumulating counter 14 to the flow rate calculation circuit 51 is outside the range of n1 to n2, the judgment circuit 61 judges that the flow rate calculation circuit 51 should use the flow rate/number of times overturned correlation function for the entire flow rate range shown in FIG. 15(A).

When the flow rate calculation circuit 51 calculates the flow rate of water flowing into the bucket 11, if the value of the flow rate calculation parameter input to the flow rate calculation means 51, i.e., the value of the overturning time interval T of the bucket 11 input from the timer 41 to the flow rate calculation circuit 51, is in the range of t1 to t2, the judgment circuit 61 judges that the flow rate calculation circuit 51 should use the flow rate/overturning time interval correlation function for the specific flow rate region Y shown in FIG. 16(B). When the value of the overturning time interval T of the bucket 11 input from the timer 41 to the flow rate calculation circuit 51 is outside the range of t1 to t2, the judgment circuit 61 judges that the flow rate calculation circuit 51 should use the flow rate/overturning time interval correlation function for the entire flow rate region shown in FIG. 16(A).

As configured as above, the fourth embodiment achieves the same effects as the effects (1) to (5) of the first to third embodiments, and also achieves the following effect (6).
(6) The judgment circuit 61 judges which of the two types of functions, the total flow rate range and the specific flow rate range Y, prepared for each of the flow rate vs. fall count correlation function and the flow rate vs. fall time interval correlation function, should be used by the flow rate calculation circuit 11 based on the number of falls N or the fall time interval T input to the flow rate calculation circuit 51. Therefore, when the flow rate calculation circuit 51 uses the correlation function for the specific flow rate range Y in particular, the correlation function for the specific flow rate range Y is approximate to the actual characteristics, so that the measurement accuracy of the flow rate in this specific flow rate range Y can be improved.

[E] Fifth embodiment (FIGS. 17 to 19)
17 is a block diagram showing the flow of data processing in a bucket type flowmeter according to the fifth embodiment. In the fifth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be simplified or omitted.

The bucket type flowmeter 70 of the fifth embodiment differs from the first to fourth embodiments in that it has an acceleration sensor or force sensor (acceleration sensor 71 in the fifth embodiment) as an impact sensor that detects the impact when the bucket 11 tips over, an impact force calculation circuit 72 as an impact force calculation means that calculates the impact force when the bucket 11 tips over from the sensor signal of the acceleration sensor 71, and a flow rate calculation circuit 73 as a flow rate calculation means that calculates the flow rate of water flowing into the bucket 11 using the impact force when the bucket 11 tips over.

The acceleration sensor 71 is installed on at least one of the case 16 and the seat panel 22, as shown by the two-dot chain line in FIG. 1. The greater the flow rate of water flowing into the bucket 11 from the inlet 17, the more forcefully the bucket 11 will tip over. Therefore, as shown in FIG. 18, the sensor signal (detection signal) from the acceleration sensor 71, which detects the impact when the bucket 11 tips over, has a larger amplitude J2 when the water flowing into the bucket 11 is at a high flow rate than the amplitude J1 when the water flowing into the bucket 11 is at a low flow rate. From the values of the amplitudes J1 and J2 of this sensor signal, the impact force calculation circuit 72 calculates the impact force.

The flow rate calculation circuit 73 uses the impact force calculated from the sensor signal of the acceleration sensor 71 as a flow rate calculation parameter, and calculates the water flow rate based on this flow rate calculation parameter. In other words, the flow rate calculation circuit 73 calculates the flow rate of water flowing into the bucket 11 from the impact force calculated by the impact force calculation circuit 72 based on the flow rate/impact force correlation function shown in FIG. 19, which defines the relationship between the flow rate of water flowing into the bucket 11 from the inlet 17 and the impact force calculated by the impact force calculation circuit 72 from the sensor signal of the acceleration sensor 71.

As configured as above, the fifth embodiment provides the following effect (7).
(7) The acceleration sensor 71 detects the impact when the bucket 11 tips over once, the impact force calculation circuit 72 calculates the impact force from the sensor signal of this acceleration sensor 71, and the flow rate calculation circuit 73 uses this impact force to calculate the flow rate of water flowing into the bucket 11 based on a flow rate/impact force correlation function. Therefore, the flow rate measurement information can be updated every time the bucket 11 tips over. Furthermore, unlike the reed switch 31, the acceleration sensor 71 does not have a drive unit, so maintenance of the acceleration sensor 71 is not required.

[F] Sixth embodiment (FIGS. 20 to 23)
20 is a block diagram showing the flow of data processing in a bucket type flowmeter according to the sixth embodiment. In the sixth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be simplified or omitted.

The bucket type flowmeter 80 of the sixth embodiment differs from the first embodiment in that, as shown in Figures 20 and 21, it has an operation time detection circuit 81 that detects the widths Ua and Ub of the pulse signals output from the reed switch 31 of the detection unit 13 via the detection circuit 32 as operation times, a tipping direction confirmation circuit 82 as tipping direction confirmation means that confirms the tipping direction of the bucket 11 from the difference c between the operation times Ua and Ub detected by the operation time detection circuit 81, and a flow rate calculation circuit 83 as flow rate calculation means that calculates the flow rate of water flowing into the bucket 11 using the operation times Ua and Ub detected by the operation time detection circuit 81.

By adjusting the distance between the magnet 30 and the reed switch 31, the detection unit 13 can generate a difference c between the operation time Ua when the bucket 11 is tipping to the left and the operation time Ub when the bucket 11 is tipping to the right, as shown in FIG. 21. The tipping direction confirmation circuit 82 confirms that the bucket 11 is tipping alternately left and right when the difference c exists between the adjacent operation times Ua and Ub output from the reed switch 31.

As shown in FIG. 22, the operating time of the reed switch 31 is Ua, Ub when the flow rate of water flowing into the bucket 11 from the inlet 17 is low, but when the flow rate is high, it decreases by the same time d in both the left and right overturning directions, changing to Ua1, Ub1 (Ua1<Ua, Ub1<Ub). Note that even in these high flow rate operating times Ua1, Ub1, the time difference c in the left and right overturning directions of the bucket 11 is maintained.

The flow rate calculation circuit 83 shown in FIG. 20 uses the operating time of the reed switch 31 as a flow rate calculation parameter, and calculates the water flow rate based on this flow rate calculation parameter. In other words, the flow rate calculation circuit 83 calculates the flow rate of water flowing into the bucket 11 from the operating times Ua (Ua1) and Ub (Ub1) of the reed switch 31 detected by the operating time detection circuit 81, based on the flow rate/operating time correlation function shown in FIG. 23, which defines the relationship between the flow rate of water flowing into the bucket 11 from the inlet 17 and the operating times Ua (Ua1) and Ub (Ub1) of the reed switch 31.

As configured as above, the sixth embodiment provides the following effect (8).
(8) The overturning direction confirmation circuit 82 confirms the overturning direction of the bucket 11 from the difference c between the operation times Ua (Ua1), Ub (Ub1) in the left and right overturning directions of the bucket 11, so it is possible to determine whether the bucket 11 is overturning alternately left and right. In addition, the flow rate calculation circuit 83 calculates the flow rate of water flowing into the bucket 11 from changes in the overturning times Ua (Ua1), Ub (Ub1) of the bucket 11 for one overturning on the left and right, respectively, so it is possible to update the flow rate measurement information every time the bucket 11 overturns.

[G] Seventh embodiment (FIGS. 24 to 26)
24 is a block diagram showing the flow of data processing in a bucket type flowmeter according to a seventh embodiment. In the seventh embodiment, the same parts as those in the fifth and sixth embodiments are denoted by the same reference numerals as those in the fifth and sixth embodiments, and the description thereof will be simplified or omitted.

The bucket type flowmeter 90 of the seventh embodiment differs from the fifth and sixth embodiments in that two types of functions, an overall flow range (Fig. 25(A), Fig. 26(A)) and a specific flow range (Fig. 25(B), Fig. 26(B)), are prepared for each correlation function between the flow calculation parameters and the flow rate (i.e., the flow rate/impact force correlation function or the flow rate/operation time correlation function), and a determination circuit 91 is provided as a determination means for determining which of the two types of functions the flow rate calculation circuits 73, 83 should use.

Here, the specific flow rate range is, for example, the specific flow rate range Y near the set value X (Fig. 25(B) and Fig. 26(B)) that generates an alarm. The total flow rate range is a wide range of flow rate that includes the specific flow rate range Y. In particular, the functions of the specific flow rate range Y (flow rate-impact force correlation function, flow rate-operation time correlation function) have a denser number of plots than the correlation functions of the total flow rate range, and are closer to the actual characteristics measured in advance.

The specific flow rate range Y in the flow rate/impact force correlation function corresponds to the range of impact force p1 to p2 on the bucket 11. Also, the specific flow rate range Y in the flow rate/operation time correlation function corresponds to the range of operation time q1 to q2 of the reed switch 31.

When the flow rate calculation circuit 73 calculates the flow rate of water flowing into the bucket 11, if the value of the flow rate calculation parameter input to the flow rate calculation circuit 73, i.e., the value of the impact force on the bucket 11 input from the impact force calculation circuit 72 to the flow rate calculation circuit 73, is in the range of p1 to p2, the judgment circuit 91 judges that the flow rate calculation circuit 73 should use the flow rate/impact force correlation function for the specific flow rate region Y shown in FIG. 25(B). In addition, if the value of the impact force on the bucket 11 input from the impact force calculation circuit 72 to the flow rate calculation circuit 73 is outside the range of p1 to p2, the judgment circuit 91 judges that the flow rate calculation circuit 73 should use the flow rate/impact force correlation function for the entire flow rate region shown in FIG. 25(A).

When the flow rate calculation circuit 83 calculates the flow rate of water flowing into the bucket 11, if the value of the flow rate calculation parameter input to the flow rate calculation circuit 83, i.e., the value of the operation time of the reed switch 31 input from the operation time detection circuit 81 to the flow rate calculation circuit 83, is in the range of q1 to q2, the judgment circuit 91 judges that the flow rate calculation circuit 83 should use the flow rate/operation time correlation function for the specific flow rate range Y shown in FIG. 26(B). When the value of the operation time of the reed switch 31 input from the operation time detection circuit 81 to the flow rate calculation circuit 83 is outside the range of q1 to q2, the judgment circuit 91 judges that the flow rate calculation circuit 83 should use the flow rate/operation time correlation function for the entire flow rate range shown in FIG. 26(A).

As configured as described above, the seventh embodiment achieves the same effects as the effects (7) and (8) of the fifth and sixth embodiments, and also achieves the following effect (9).
(9) The judgment circuit 91 judges which of the two types of functions, the entire flow rate range and the specific flow rate range Y, prepared for each of the flow rate/impact force correlation function and the flow rate/operation time correlation function, the flow rate calculation circuits 73, 83 should use based on the impact force on the bucket 11 input to the flow rate calculation circuit 73 and the operation time of the reed switch 31 input to the flow rate calculation circuit 83. Therefore, particularly when the flow rate calculation circuits 73, 83 use the correlation function for the specific flow rate range Y, the measurement accuracy of the flow rate in this specific flow rate range Y can be improved because the correlation function for this specific flow rate range Y is approximate to the actual characteristics.

[H] Eighth embodiment (FIG. 27)
27 is a block diagram mainly showing the flow of data processing in a bucket type flowmeter according to an eighth embodiment. In the eighth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be simplified or omitted.

The bucket-type flowmeter 100 of the eighth embodiment differs from the first embodiment in that it has a temperature sensor 101 that is provided in the water supply pipe 20 through which water flows and detects the temperature of the water, and a temperature correction circuit 102 that serves as a temperature correction means for calculating the amount of water evaporation during the flow measurement time from the water temperature detected by this temperature sensor 101 and adding this evaporation amount to the water flow rate calculated by the flow rate calculation circuit 15 for correction.

If the water flowing into the bucket 11 from the inlet 17 is hot, it evaporates before the bucket 11 tips over, and the water flow rate measurement due to the tipping over of the bucket 11 is not reflected. Therefore, the temperature correction circuit 102 calculates the amount of water that evaporates between the time when the water flows into the bucket 11 from the inlet 17 and the time when the bucket 11 tips over from the water temperature detected by the temperature sensor 101, and adds the value obtained by multiplying this amount of water by the number of times N that the bucket 11 tips over to the water flow rate calculated by the flow rate calculation circuit 15 to correct the flow rate.

As configured as above, the eighth embodiment achieves the same effects as the effects (1) and (2) of the first embodiment, as well as the following effect (9).
(9) The temperature correction circuit 102 calculates the amount of evaporation of the water flowing into the bucket 11 from the water temperature detected by the temperature sensor 101, and corrects the amount of evaporation by adding it to the water flow rate calculated by the flow rate calculation circuit 15. Therefore, even if the water temperature is high and some of it evaporates, the accuracy of measuring the flow rate can be improved.

Note that the eighth embodiment is not limited to application to the first embodiment, but can be applied to each of the second to seventh embodiments. Therefore, in these cases, in addition to the effect (9) of the eighth embodiment, the effects of each of the second to seventh embodiments are also achieved.

Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Furthermore, these substitutions and modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims.
For example, in the first to eighth embodiments, the liquid for which the flow rate is to be measured is water, but the liquid may be other liquids than water, such as alcohol.

10...bucket type flowmeter, 11...bucket, 12...regulation unit (regulation means), 13...detection unit (detection means), 14...accumulation counter (accumulation count means), 15...flow rate calculation circuit (flow rate calculation means), 17...inlet section, 18, 19...box section, 23A, 23B...fulcrum, 25, 26...ferrule, 30...magnet, 31...reed switch, 33...ferrule adjustment mechanism, 40...bucket type flowmeter, 41...timer (timer means), 43...average circuit (average value calculation means), 44...flow rate calculation circuit (flow rate calculation means), 50...bucket type flowmeter, 51...flow rate calculation circuit (flow rate calculation means), 52...remaining time detection circuit (remaining time detection means), 53...remaining amount calculation circuit (remaining amount calculation means), 54...flow rate addition/subtraction circuit (correction means), 60...bucket type flow meter, 61...judgment circuit (judgment means), 70...bucket type flow meter, 71...acceleration sensor (shock sensor), 73...flow rate calculation circuit (flow rate calculation means), 80...bucket type flow meter, 82...falling direction confirmation circuit (falling direction confirmation means), 83...flow rate calculation circuit (flow rate calculation means), 90...bucket type flow meter, 91...judgment circuit (judgment means), 100...bucket type flow meter, 101...temperature sensor, 102...temperature correction circuit (temperature correction means), i...external signal, M...remaining time, N...number of falls, Se...end time, T...falling time interval, Ua, Ub...operation time, Y...specific flow rate range

Claims (3)

a bucket having a pair of containers formed on both sides of a fulcrum and rotatably disposed about the fulcrum, the bucket being tipped over when a predetermined amount of liquid flows into the containers from an inlet and is accumulated therein;
an impact sensor for detecting an impact when the bucket overturns;
a flow rate calculation means for calculating a flow rate of the liquid based on the impact force obtained from the detection signal of the impact sensor and a flow rate/impact force correlation function that defines the relationship between the flow rate of the liquid and the impact force. 2. The bucket type flowmeter according to claim 1 , further comprising a determination means for determining which of the two types of functions the flow rate calculation means should use from the value of the impact force input to the flow rate calculation means when the flow rate calculation means calculates the flow rate, wherein two types of functions are prepared for the flow rate/impact force correlation function, one for an entire flow rate range and one for a specific flow rate range, and wherein the flow rate calculation means determines which of the two types of functions the flow rate calculation means should use from the value of the impact force input to the flow rate calculation means. a temperature sensor provided in a pipe through which the fluid flows and detecting a temperature of the liquid;
3. The bucket type flowmeter according to claim 1, further comprising: a temperature correction means for calculating an amount of evaporation of the liquid that evaporates within a flow rate measurement time from the temperature of the liquid detected by the temperature sensor, and adding this evaporation amount to the flow rate of the liquid calculated by the flow rate calculation means for correction.

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