Bucket type flow meter

Abstract

To improve accuracy of measuring a flow rate of liquid in a specific flow rate range.SOLUTION: A bucket type flow meter includes: a bucket 11 having a pair of basin portions formed on both sides of a fulcrum and rotatably provided by pivoting about the fulcrum, which tumbles and drains liquid when a predetermined amount of liquid flows into the basin portions from an inlet; a detection unit 13 that detects tumbling of this bucket; a tumbling direction confirmation circuit 82 that confirms a tumbling direction of the bucket from a difference of operation time of this detection unit; and a flow rate calculation circuit 83 that uses the operation time of the detection unit as a flow rate calculation parameter and calculates a flow rate of the liquid on the basis of this flow rate calculation parameter.SELECTED DRAWING: Figure 20

Description

[Technical Field]

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to a bucket-type flow meter. [Background technology]

[0002] The basic principle of a bucket flow meter is that the liquid flowing in from the inlet is received by a bucket (tipping box) divided into two halves, left and right, and when the liquid accumulates, the bucket begins to tip over on the side where the liquid has accumulated, and the other side repeats this cycle of receiving the liquid. The tipping action 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 drained liquid per tipping.

[0003] Because the bucket is filled with liquid once, it is suitable for measuring minute flow rates, but errors occur due to various factors.For this reason, conventionally, the accuracy of flow rate measurement has been ensured by methods such as 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, calculating the flow rate from the number of tippings, installing a lid on the bucket that opens only when the bucket is tipping to prevent spillage, or correcting the amount of spillage from the tipping interval, bucket capacity, and a constant calculated from tests. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-237056 Summary of the Invention [Problem to be solved by the invention]

[0005] Bucket flow meters are used in general industrial rain gauges as well as for leak detection at nuclear power plants, and there are currently plans to review their measurement accuracy in low flow ranges. Since the accuracy guaranteed by conventional methods is not reliable enough, further improvements in measurement accuracy are required. Furthermore, because the flow rate is calculated by sampling the number of times the bucket tips over, rather than through continuous monitoring, it takes time to update the measured flow rate.

[0006] The embodiments of the present invention have been made in consideration of the above circumstances, and an object of the present invention is to provide a bucket type flowmeter that can improve the measurement accuracy of the flow rate of a liquid in a specific flow rate range. [Means for solving the problem]

[0007] A bucket type flow meter according to an embodiment of the present invention includes a bucket having a pair of measuring sections formed on both sides of a fulcrum and rotatable about the fulcrum, the bucket being tipped over to drain the liquid when a predetermined amount of liquid flows into the measuring section from an inlet section, and a detector for detecting the tipping of the bucket. At the same time, the operation time when the bucket is overturned in one direction is different from the operation time when the bucket is overturned in the other direction. A detection sensor; From the time difference between the operation time when the bucket is tipping in one direction and the operation time when the bucket is tipping in the other direction, The device is characterized by having a tipping direction confirmation means for confirming the tipping direction of the bucket, and a flow rate calculation means for calculating the flow rate of the liquid based on the flow rate calculation parameter, using the operating time of the detection sensor as a flow rate calculation parameter. [Effects of the Invention]

[0008] According to the 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. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front cross-sectional view showing a bucket type flowmeter according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing a bucket and a detection unit of the bucket type flowmeter of FIG. 1. [Figure 3] 2 is an operational diagram illustrating the operation of the bucket flowmeter of FIG. 1. [Figure 4] FIG. 2 is a block diagram showing the flow of data processing in the bucket type flowmeter of FIG. 1. [Figure 5] 2 is a graph showing a correlation function between the flow rate of water to be measured and the amount of water discharged per one tipping of the bucket in the bucket-type flow meter of FIG. 1. [Figure 6] 5 is a graph showing a correlation function between flow rate and number of falls used in the flow rate calculation circuit of FIG. 4. [Figure 7]2 is a graph showing the relationship between the flow rate characteristics of the bucket-type flowmeter of FIG. 1 and adjustment of the displacement per bucket overturning. [Figure 8] FIG. 4 is a diagram showing an example of a ferrule adjustment mechanism. [Figure 9] FIG. 10 is a block diagram showing the flow of data processing in the bucket type flowmeter according to the second embodiment. [Figure 10] 10 is a time chart illustrating the fall time interval detected by the timer in FIG. 9; [Figure 11] 10 is a graph showing a correlation function between flow rate and fall time interval used in the flow rate calculation circuit of FIG. 9. [Figure 12] FIG. 11 is a block diagram showing the flow of data processing in a bucket type flowmeter according to a third embodiment. [Figure 13] 13 is a time chart for explaining the remaining time and overturning time interval required for the remaining amount calculation circuit of FIG. 12 to calculate the remaining amount of water in the bucket. [Figure 14] FIG. 10 is a block diagram showing the flow of data processing in a bucket type flowmeter according to a fourth embodiment. [Figure 15] 15A and 15B are graphs showing the correlation function between flow rate and number of falls determined by the determination circuit of FIG. 14, where (A) shows the same function in the entire flow rate range and (B) shows the same function in a specific flow rate range. [Figure 16] 15A and 15B are graphs showing the correlation function between flow rate and time interval between falls determined by the determination circuit of FIG. 14, where (A) shows the same function in the entire flow rate range and (B) shows the same function in a specific flow rate range. [Figure 17] FIG. 11 is a block diagram showing the flow of data processing in a bucket type flowmeter according to a fifth embodiment. [Figure 18] 18 is a time chart showing a sensor signal output from the acceleration sensor of FIG. 17; [Figure 19] 18 is a graph showing a correlation function between flow rate and impact force used in the flow rate calculation circuit of FIG. 17. [Figure 20] FIG. 13 is a block diagram showing the flow of data processing in a bucket type flowmeter according to a sixth embodiment. [Figure 21] 21 is a time chart for explaining the operation time of a reed switch used by the overturning direction confirmation circuit of FIG. 20 to confirm the overturning direction of the bucket. [Figure 22] 21 is a time chart for explaining the operating time of a reed switch input to the flow rate calculation circuit of FIG. 20. [Figure 23] 21 is a graph showing a flow rate-operating time correlation function used in the flow rate calculation circuit of FIG. 20. [Figure 24] FIG. 13 is a block diagram showing the flow of data processing in a bucket type flowmeter according to a seventh embodiment. [Figure 25] 25A and 25B are graphs showing the flow rate-impact force correlation function determined by the determination circuit of FIG. 24, where (a) is the same function in the entire flow rate range, and (b) is the same function in a specific flow rate range. [Figure 26] 25A and 25B are graphs showing the flow rate-operating time correlation function determined by the determination circuit of FIG. 24, where (a) is the same function in the entire flow rate range, and (B) is the same function in a specific flow rate range. [Figure 27] FIG. 13 is a block diagram mainly showing the flow of data processing in a bucket type flowmeter according to an eighth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] 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. A bucket type flowmeter 10 shown in Figs. 1 and 2 measures the flow rate of water as a liquid flowing through a water supply pipe 20, and as shown in Figs. 1, 2, and 4, is configured to include 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.

[0011] Case 16 is formed by fixing cover plates 16B (only one of which is shown in FIG. 1) to both ends of a substantially cylindrical case body 16A. An inlet 17 projects inward from the top of case body 16A, and the downstream end of a water supply pipe 20 is connected to this inlet 17. Water supplied from water supply pipe 20 flows (downstream) from inlet 17 into a manhole 18 or 19 (both described below) of bucket 11. The upstream end of a drainage pipe 21 is connected to the bottom of case body 16A.

[0012] Seat plates 22 (only one of which is shown in FIG. 1) are fixed to both cover plates 16B of case 16 using bolts or the like. One of the seat plates 22 pivots at one fulcrum 23A of bucket 11, and the other fulcrum 23B of bucket 11 pivots at a mounting plate 24 fixed to the other seat plate 22 (not shown).

[0013] Bucket 11 has a pair of boxes 18, 19 formed on both the left and right sides of coaxial supports 23A and 23B. Water flows into these boxes 18 or 19 from inlet 17 and is stored in a predetermined amount. Here, boxes 18 and 19 are set to have the same capacity. When a predetermined amount of water is stored in box 18 or 19, bucket 11 rotates around supports 23A and 23B due to the action of gravity on the stored water, causing it to tip over and discharge the stored water. The water discharged from bucket 11 flows down into case body 16A of case 16 and is then led to drainage pipe 21.

[0014] The restriction unit 12 restricts the tipping stop position of the bucket 11 and is composed of length-adjustable protrusions 25 and 26 and stoppers 27 and 28. Protrusion 25 is attached to the bottom of box portion 18 of the bucket 11, and protrusion 26 is attached to the bottom of box portion 19. Stoppers 27 and 28 are embedded in the seat board 22. The left and right tipping stop positions of the bucket 11 are restricted by protrusion 25 abutting against stopper 27 and protrusion 26 abutting against stopper 28, respectively.

[0015] As shown in Figure 3, when water flows into box portion 19 of bucket 11 from inlet portion 17 and accumulates in a predetermined amount, bucket 11 rotates clockwise in Figure 3 around fulcrums 23A and 23B and overturns, and ferrule 26 abuts stopper 28 to stop the overturning motion and drain water from box portion 19 of bucket 11. At this time, box portion 18 of bucket 11 is positioned opposite inlet portion 17, so water then flows from inlet portion 17 into box portion 18.

[0016] When a predetermined amount of water has accumulated in box portion 18, bucket 11 rotates counterclockwise in Figure 3 around fulcrums 23A and 23B and tips over, and ferrule 25 abuts stopper 27 to stop the tipping motion and drain water from box portion 18 of bucket 11. In this way, bucket 11 alternately accumulates water in box portions 18 and 19 and drains the water by tipping over.

[0017] The detection unit 13 shown in FIG. 2 detects the tipping over of the bucket 11, and is configured to include 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.

[0018] Reed switch 31 is mounted on mounting plate 24 and positioned below fulcrums 23A and 23B of bucket 11. Therefore, when bucket 11 tips over, magnet 30 moves with bucket 11, and the magnetic force of this moving magnet 30 causes reed switch 31 to turn from OFF to ON, outputting a pulse signal. This pulse signal is output one pulse per rotation of bucket 11. The pulse signal from reed switch 31 has noise, for example, removed by detection circuit 32, and is output to integrating counter 14 shown in FIG. 4.

[0019] Integrating counter 14 counts and integrates the pulse signals from detection circuit 32 of detection unit 13 per unit time (for example, one minute) to count the number N of times bucket 11 has overturned. Here, as shown in FIG. 5, the amount of water discharged per overturn of bucket 11 (hereinafter referred to as the "amount of water discharged per overturn") increases mainly when the flow rate of water flowing from inlet 17 into manhole 18 or 19 of bucket 11 increases. Therefore, in consideration of the flow rate-one-overturn discharge correlation function shown in FIG. 5 which defines the relationship between the flow rate of water flowing from inlet 17 into manhole 18 or 19 of bucket 11 and the amount of water discharged per overturn of bucket 11, a flow rate-number-of-overturns correlation function which defines the relationship between the flow rate of water flowing from inlet 17 into manhole 18 or 19 of bucket 11 and the number of times bucket 11 has overturned is calculated in advance, as shown in FIG. 6.

[0020] Flow rate calculation circuit 15 uses the number of overturns as a flow rate calculation parameter and calculates the water flow rate based on this flow rate calculation parameter. In other words, flow rate calculation circuit 15 calculates the flow rate of water flowing into bucket 11 from inlet 17, i.e., the flow rate of water flowing through water supply pipe 20, from the number of overturns N of bucket 11 counted by integrating counter 14, based on the flow rate vs. number of overturns correlation function (FIG. 6) described above, and outputs this as a flow rate signal to the outside.

[0021] As described above, when the flow rate of water flowing into bucket 11 from inlet portion 17 increases, the one-time tipping displacement of bucket 11 mainly increases (FIG. 5). Also, if the length of projections 25, 26 of regulating unit 12 shown in FIG. 1 is adjusted to be longer and the tipping stop position of bucket 11 is set higher (raised), the one-time tipping displacement of bucket 11 decreases, as shown in FIG. 7. Therefore, the tipping stop position of bucket 11 is set by adjusting the lengths of projections 25 and 26 (for example, as shown by the solid line in FIG. 7) so that the change in the one-time tipping displacement of bucket 11 relative to the change in flow rate in specific flow rate range Y near set value X for alarm generation (FIG. 7) becomes small (i.e., the one-time tipping displacement becomes approximately constant). Here, specific flow rate range Y is set, for example, to include set value X and be 20% of the entire flow rate range or narrower.

[0022] As described above, the flow rate of water flowing into bucket 11 from inlet 17 is calculated by flow rate calculation circuit 15 from the number of times bucket 11 overturns using the flow rate vs. number of overturns correlation function (see Figure 6) calculated from the flow rate vs. one-overturn displacement correlation function (see Figure 5) when the length of ferrules 25 and 26 is adjusted.

[0023] The lengths of the ferrules 25 and 26 in the regulating unit 12 may be adjusted manually or automatically in response to an external signal i using a 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 attached to the lower end of the movable bar 35. A magnet (electromagnet or permanent magnet) 36 is also attached to the upper end of the movable bar 35 provided 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 in response to an external signal i, thereby moving the movable bar 35 via the magnet 36 and adjusting the positions of the ferrules 25 and 26.

[0024] As configured as above, the first embodiment provides the following effects (1) and (2). (1) The length of protrusions 25 and 26 of regulating unit 12 is adjusted to set the tipping stop position of bucket 11 so that the change in the per-tipping displacement of bucket 11 is small relative to the change in flow rate in specific flow rate range Y of water flowing into bucket 11 from inlet portion 17 (i.e., the per-tipping displacement becomes approximately constant), and flow rate calculation means 15 calculates and measures the flow rate from the number of tippings N counted by integrating counter 14, based on the flow rate vs. number of tippings correlation function calculated from the flow rate vs. per-tipping displacement correlation function at this time. This improves the accuracy of measuring the flow rate in specific flow rate range Y of water, and as a result, prevents false alarms from being issued.

[0025] (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 flow meter 10 is installed in a location that is difficult for workers to access, the displacement amount 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.

[0026] [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 this second embodiment, parts that are the same as those in the first embodiment are given the same reference numerals as in the first embodiment, and descriptions thereof will be simplified or omitted.

[0027] A bucket type flowmeter 40 of the second embodiment differs from the first embodiment in that, instead of the integrating counter 14 and the flow rate calculation circuit 15, the bucket type flowmeter 40 has a timer 41 as 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 average value calculation means for calculating an average value from a plurality of overturning time intervals, and a flow rate calculation circuit 44 as flow rate calculation means for calculating the flow rate of water flowing into the bucket 11 from the overturning time interval or the average value.

[0028] In other words, the timer 41 detects the overturn time interval T per overturn from one overturn of the bucket 11 to the next overturn 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.

[0029] Memory circuit 42 holds the overturning time interval T of bucket 11 output from timer 41. Furthermore, the flow rate of water flowing into bucket 11 may fluctuate instantaneously, causing the overturning time interval of pulse signal PS to change to a value T1 different from T, as shown in Fig. 10. Taking this into consideration, averaging circuit 43 calculates an average value by averaging the multiple overturning time intervals T, T1, ... of bucket 11 held in memory circuit 42.

[0030] 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 intervals calculated by averaging circuit 43 as a flow rate calculation parameter, and calculates the flow rate of water based on these flow rate calculation parameters. In other words, 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 bucket 11 from inlet portion 17 and the overturning time interval T of bucket 11. Next, flow rate calculation circuit 44 calculates the flow rate Va of water flowing into bucket 11 from the overturning time interval Ta of bucket 11 output from timer 41 based on this flow rate-overturning time interval correlation function, and calculates the flow rate Vb of water flowing into bucket 11 from the average value Tb of the overturning time interval T of bucket 11 output from averaging circuit 43.

[0031] As configured as above, the second embodiment provides the following effects (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.

[0032] (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.

[0033] [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, parts that are similar to those in the first and second embodiments are given the same reference numerals as in the first and second embodiments, and their explanations will be simplified or omitted.

[0034] A bucket type flowmeter 50 of the third embodiment differs from the first and second embodiments in that a flow rate calculation circuit 51 as flow rate 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 in that the bucket type flowmeter 50 has a remaining time detection circuit 52 as remaining time detection means, a remaining amount calculation circuit 53 as remaining amount calculation means, and a flow rate addition / subtraction circuit 54 as correction means.

[0035] Using pulse signals from reed switch 31 and detection circuit 32, remaining time detection circuit 52 detects the remaining time M from the rise time S of the last tipping of bucket 11 within one cycle in which integrating counter 14 counts the number of times N that bucket 11 has tipped over to the end time Se of the one cycle.

[0036] The remaining amount calculation circuit 53 first finds 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 per overturning of the bucket 11 at the time when the flow rate calculation circuit 51 calculated 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 within the one cycle.

[0037] The flow rate addition / subtraction circuit 54 corrects the water flow rate calculated by the flow rate calculation circuit 51 in the first function using the remaining amount of water calculated by the remaining amount calculation circuit 53. 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 circuit 51 to correct the flow rate. Furthermore, since 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, this amount 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.

[0038] As configured as above, the third embodiment provides the following effect (5) in addition to the effects (1) to (4) of the first and second embodiments. (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 has tipped over, 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 has tipped over.

[0039] [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 this fourth embodiment, parts that are similar to those in the first to third embodiments are given the same reference numerals as in the first to third embodiments, and descriptions thereof will be simplified or omitted.

[0040] The bucket type flowmeter 60 of the fourth embodiment differs from the first to third embodiments in that two types of functions are prepared for each of the correlation functions between the flow rate calculation parameters and the flow rate (i.e., the flow rate vs. number of overturns correlation function or the flow rate vs. time interval between overturns), one for the entire flow rate range (FIGS. 15(A) and 16(A)) and the other for a specific flow rate range (FIGS. 15(B) and 16(B)), and the flow rate calculation circuit 51 has a determination circuit 61 as determination means for determining which of the two types of functions to use.

[0041] Here, the specific flow rate range is, for example, the specific flow rate range Y near the set point X (Fig. 15(B), Fig. 16(B)) that generates an alarm. The overall 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 flow rate and number of falls, and the correlation function between flow rate and time interval between falls) have a denser number of plots than the correlation functions of the overall flow rate range, and are closer to the actual characteristics measured in advance.

[0042] The specific flow rate range Y in the flow rate vs. tipping count correlation function corresponds to the range of n1 to n2 in the number of tipping count N of the bucket 11. Also, the specific flow rate range Y in the flow rate vs. tipping time interval correlation function corresponds to the range of t1 to t2 in the tipping time interval T of the bucket 11.

[0043] When the flow rate of water flowing into the bucket 11 is calculated by the flow rate calculation circuit 51, if the value of the flow rate calculation parameter input to the flow rate calculation circuit 51, i.e., the value of the number of times N the bucket 11 has overturned input from the integrating counter 14 to the flow rate calculation circuit 51, is in the range of n1 to n2, the determination circuit 61 determines that the flow rate calculation circuit 51 should use the flow rate vs. number of times overturned of the specific flow rate range Y shown in Figure 15(B). Also, if the value of the number of times N the bucket 11 has overturned input to the flow rate calculation circuit 51 from the integrating counter 14 is outside the range of n1 to n2, the determination circuit 61 determines that the flow rate calculation circuit 51 should use the flow rate vs. number of times overturned of the entire flow rate range shown in Figure 15(A).

[0044] Furthermore, 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 circuit 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 vs. overturning time interval correlation function for the specific flow rate range Y shown in Figure 16(B). Furthermore, if 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 vs. overturning time interval correlation function for the entire flow rate range shown in Figure 16(A).

[0045] As configured as above, the fourth embodiment provides the following effect (6) in addition to the effects (1) to (5) of the first to third embodiments. (6) The determination circuit 61 determines which of the two functions for the entire flow rate range and the specific flow rate range Y, which are prepared for the flow rate vs. number of falls correlation function or 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 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 close to the actual characteristics, and therefore the measurement accuracy of the flow rate in this specific flow rate range Y can be improved.

[0046] [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, parts that are the same as those in the first embodiment are given the same reference numerals as in the first embodiment, and descriptions thereof will be simplified or omitted.

[0047] The bucket type flow meter 70 of the fifth embodiment differs from the first to fourth embodiments in that it includes 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 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 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.

[0048] Acceleration sensor 71 is installed on at least one of case 16 and seat panel 22, as indicated by the two-dot chain line in Fig. 1. The greater the flow rate of water flowing into bucket 11 from inlet portion 17, the more forcefully bucket 11 will tip over, and so the sensor signal (detection signal) from acceleration sensor 71, which detects the impact when bucket 11 tips over, has a larger amplitude J2 when the flow rate of water flowing into bucket 11 is high than an amplitude J1 when the flow rate is low, as shown in Fig. 18. An impact force calculation circuit 72 calculates the impact force from the values ​​of amplitudes J1 and J2 of this sensor signal.

[0049] The flow rate calculation circuit 73 uses the impact force determined from the sensor signal of the acceleration sensor 71 as a flow rate calculation parameter and calculates the flow rate of water 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 determined by the impact force calculation circuit 72, based on the flow rate-impact force correlation function shown in Figure 19 which defines the relationship between the flow rate of water flowing into the bucket 11 from the inlet portion 17 and the impact force calculated by the impact force calculation circuit 72 from the sensor signal of the acceleration sensor 71.

[0050] 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.

[0051] [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 in the first embodiment are denoted by the same reference numerals as in the first embodiment, and the description thereof will be simplified or omitted.

[0052] A bucket type flowmeter 80 of the sixth embodiment differs from the first embodiment in that, as shown in FIGS. 20 and 21 , it has an operation time detection circuit 81 that detects, as operation time, the widths Ua and Ub of the pulse signal output from the reed switch 31 of the detection unit 13 via the detection circuit 32, an overturning direction confirmation circuit 82 as overturning direction confirmation means that confirms the overturning 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.

[0053] By adjusting the distance between the magnet 30 and the reed switch 31, etc., 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 adjacent operation times Ua and Ub output from this reed switch 31.

[0054] As shown in Fig. 22, the operating times of the reed switch 31 are Ua and Ub when the flow rate of water flowing from the inflow section 17 into the bucket 11 is low. When the flow rate becomes high, the operating times decrease by the same time d in the left and right tipping directions and change to Ua1 and Ub1 (Ua1 < Ua, Ub1 < Ub). Note that even at these high-flow operating times Ua1 and Ub1, the time difference c in the left and right tipping directions of the bucket 11 is maintained.

[0055] The flow rate calculation circuit 83 shown in Fig. 20 uses the operating time of the reed switch 31 as a parameter for flow rate calculation and calculates the flow rate of water based on this parameter for flow rate calculation. That is, 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 that defines the relationship between the flow rate of water flowing from the inflow section 17 into the bucket 11 and the operating times Ua (Ua1) and Ub (Ub1) of the reed switch 31.

[0056] Due to being configured as described above, according to the sixth embodiment, the following effect (8) is achieved. (8) Since the tipping direction confirmation circuit 82 confirms the tipping direction of the bucket 11 from the difference c between the operating times Ua (Ua1) and Ub (Ub1) in the left and right tipping directions of the bucket 11, it is possible to determine that the bucket 11 is tipping alternately left and right. Also, since the flow rate calculation circuit 83 calculates the flow rate of water flowing into the bucket 11 from the change in the tipping time Ua (Ua1) and Ub (Ub1) for each of the left and right sides of the bucket 11 once, it is possible to update the measurement information of the flow rate for each tipping of the bucket 11.

[0057] [G] Seventh Embodiment (Figs. 24 to 26) Fig. 24 is a block diagram showing the flow of data processing in the bucket-type flow meter according to the seventh embodiment. Regarding parts that are the same as those in the fifth and sixth embodiments in this seventh embodiment, the description is simplified or omitted by assigning the same reference numerals as those in the fifth and sixth embodiments.

[0058] The bucket type flowmeter 90 of the seventh embodiment differs from the fifth and sixth embodiments in that two types of functions, one for the entire flow rate range (FIGS. 25(A) and 26(A)) and one for a specific flow rate range (FIGS. 25(B) and 26(B)), are prepared for each of the correlation functions between the flow rate calculation parameters and the flow rate (i.e., the flow rate-impact force correlation function or the flow rate-operating time correlation function), and the flow rate calculation circuits 73 and 83 have a determination circuit 91 as determination means for determining which of the two types of functions to use.

[0059] 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 overall 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 vs. impact force correlation function, flow rate vs. operating time correlation function) have a denser number of plots than the correlation functions of the overall flow rate range, and are closer to the actual characteristics measured in advance.

[0060] The specific flow rate range Y in the flow rate vs. impact force correlation function corresponds to the range of impact force p1 to p2 on bucket 11. Also, the specific flow rate range Y in the flow rate vs. operating time correlation function corresponds to the range of operating time q1 to q2 of reed switch 31.

[0061] 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 decision circuit 91 decides that the flow rate calculation circuit 73 should use the flow rate-impact force correlation function for the specific flow rate range Y shown in Figure 25(B). Also, 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 decision circuit 91 decides that the flow rate calculation circuit 73 should use the flow rate-impact force correlation function for the entire flow rate range shown in Figure 25(A).

[0062] Furthermore, 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 operating time of the reed switch 31 input from the operating 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-operating time correlation function for the specific flow rate range Y shown in Figure 26(B). Furthermore, if the value of the operating time of the reed switch 31 input from the operating 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-operating time correlation function for the entire flow rate range shown in Figure 26(A).

[0063] As configured as above, the seventh embodiment provides the following effect (9) in addition to the effects (7) and (8) of the fifth and sixth embodiments. (9) The determination circuit 91 determines which of the two types of functions, the overall flow rate range and the specific flow rate range Y, that the flow rate calculation circuits 73, 83 should use for each of the flow rate vs. impact force correlation function and the flow rate vs. operating time correlation function is based on the impact force on the bucket 11 input to the flow rate calculation circuit 73 and the operating time of the reed switch 31 input to the flow rate calculation circuit 83. Therefore, when the flow rate calculation circuits 73, 83 use the correlation function for the specific flow rate range Y in particular, the correlation function for the specific flow rate range Y is close to the actual characteristics, and therefore the accuracy of measuring the flow rate in this specific flow rate range Y can be improved.

[0064] [H] Eighth embodiment (Fig. 27) 27 is a block diagram mainly showing the flow of data processing in a bucket type flowmeter according to the eighth embodiment. In this eighth embodiment, the same parts as in the first embodiment are denoted by the same reference numerals as in the first embodiment, and the description thereof will be simplified or omitted.

[0065] 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 temperature correction means that calculates the amount of water evaporation within the flow rate measurement time from the water temperature detected by this temperature sensor 101 and adds this evaporation amount to the water flow rate calculated by the flow rate calculation circuit 15 for correction.

[0066] If the water flowing into bucket 11 from inlet portion 17 is hot, it will evaporate before bucket 11 tips over, and this will not be reflected in the water flow rate measurement due to the tipping of bucket 11. Therefore, temperature correction circuit 102 finds the amount of water that evaporates between the time water flows into bucket 11 from inlet portion 17 and the time bucket 11 tips over, from the water temperature detected by temperature sensor 101, and adds the value obtained by multiplying this amount of evaporation by the number of times N that bucket 11 tips over to the water flow rate calculated by flow rate calculation circuit 15 to correct the flow rate.

[0067] As configured as above, the eighth embodiment achieves the same effects as the effects (1) and (2) of the first embodiment, and also achieves the following effect (9). (9) The temperature correction circuit 102 calculates the amount of evaporation of water flowing into the bucket 11 from the water temperature detected by the temperature sensor 101, and corrects this amount of evaporation by adding it to the water flow rate calculated by the flow rate calculation circuit 15. Therefore, even when the water temperature is high and some of it evaporates, the accuracy of flow rate measurement can be improved.

[0068] 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.

[0069] 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, such substitutions and modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as set forth 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. [Explanation of symbols]

[0070] 10...bucket type flow meter, 11...bucket, 12...regulating unit (regulating means), 13...detecting unit (detecting means), 14...integrating counter (integrating counting 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 flow meter, 41...timer (timer means), 43...averaging circuit (average value calculation means), 44...flow rate calculation circuit (flow rate calculation means), 50...bucket type flow meter, 51...flow rate calculation circuit (flow rate calculation means), 52...remaining time detection circuit (remaining time detection means), 53...remaining amount calculation circuit path (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 (impact 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

1. a bucket having a pair of boxes formed on both sides of a fulcrum and rotatable about the fulcrum, the bucket being tipped over when a predetermined amount of liquid flows into the boxes from an inlet and accumulates therein; a detection sensor that detects the tipping over of the bucket and is configured so that an operating time when the bucket is tipping over in one direction is different from an operating time when the bucket is tipping over in the other direction; a tipping direction confirmation means for confirming the tipping direction of the bucket based on the time difference between an operation time when the bucket is tipping in one direction and an operation time when the bucket is tipping in the other direction; a flow rate calculation unit that calculates the flow rate of the liquid based on the flow rate calculation parameter, the operation time of the detection sensor being used as a flow rate calculation parameter.

2. 2. The bucket type flowmeter according to claim 1, further comprising: a determining means for determining, when calculating a flow rate by the flow rate calculating means, which of the two types of functions should be used by the flow rate calculating means from the value of the flow rate calculating parameter input to the flow rate calculating means, wherein two types of functions are prepared for a total flow rate range and a specific flow rate range as a correlation function between the flow rate calculation parameter and the flow rate.

3. a temperature sensor provided in a pipe through which the liquid 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 evaporation amount 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 to correct the flow rate.

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