JP5742875B2 - Liquid transport vehicles such as vacuum cars and liquid collection and metering methods using the same - Google Patents

Description

  The present invention aims to improve accuracy in liquid collection and delivery, and in particular, a liquid transport vehicle such as a vacuum car capable of measuring the collected amount of a gas-liquid mixture such as human waste with extremely high accuracy, and the same. The present invention relates to a method for measuring liquid collection and delivery.

  The human waste filled with a draw-out type toilet in a private house is regularly collected by a liquid transport vehicle called a vacuum car. A method is widely used in which the collected amount is read every time human waste is collected, and a charge corresponding to the amount of the drawn water is charged on the spot. As a method of reading the recovered amount, there is a method of visually confirming the liquid level of a glass gauge installed at the rear of the tank. While this method is easy to understand by direct viewing, it has a problem that it takes time to confirm because the glass surface is soiled with dirt and accurate visual measurement is impossible or difficult to see. In addition, there is a problem that an accurate collection amount cannot be grasped if the road surface is inclined and the vacuum car is inclined during collection.

  On the other hand, various proposals for measuring the collected amount more accurately without being affected by the inclination of the road surface have been made. For example, what is described in Patent Document 1 is to measure and display only the liquid content with an electromagnetic flow meter or an ultrasonic flow meter in which the collected amount of human waste is provided in the front stage of the tank. However, when collecting human waste with a vacuum car, air is usually sucked together with human waste, and measurement with an electromagnetic flowmeter or ultrasonic flowmeter causes a large error. Therefore, in the invention described in Patent Document 1, it is proposed to use a gas-liquid separator. However, even with such an apparatus and method, there are problems that the accuracy is still poor and that maintenance of the flowmeter takes a lot of trouble.

  Therefore, a method has been proposed in which a pressure sensor is provided in the liquid storage tank, and the liquid level is calculated to calculate the tank internal volume (see Patent Documents 2 and 3). According to such a method, since it is not a dynamic measurement method called flow velocity measurement but a static measurement method of measuring the liquid pressure once stored in the liquid storage tank, no special gas-liquid separation device is required, and vacuum is required. Car cost reduction can be realized, and quicker and more accurate weighing is possible. However, since the pressure sensor cannot be directly attached to the tank body due to rust prevention, there is a certain limit to improving accuracy.

Japanese Patent Publication No.57-44837 JP-A-7-189333 JP-A-8-4102

  Therefore, in view of the above-described situation, the present invention intends to solve a liquid such as a vacuum car that can calculate the capacity in the tank more accurately and charge the collected amount more accurately to the customer. The object is to provide a transport vehicle and a method for measuring the amount of liquid distribution using the same.

  As a result of intensive investigations for solving the above-mentioned problems, the present inventor cannot obtain the stored hydraulic pressure directly because the pressure sensor cannot be provided at the bottom of the tank, and this causes an error. In particular, it has been found that the tank capacity can be calculated more accurately by eliminating large pressure measurement errors when the transport vehicle is tilted, making it possible to bill customers more accurately for the collection amount. The present invention has been completed.

That is, the present invention relates to a liquid storage tank, a stored pressure sensor for detecting a stored liquid pressure provided near the bottom of the liquid storage tank, an arithmetic processing device for estimating a tank internal capacity based on information from the pressure sensor, and a tank An inclination angle sensor capable of detecting an inclination angle of the liquid storage tank , wherein the pressure sensor is a differential pressure sensor for detecting a differential pressure between a liquid pressure of the liquid stored in the liquid storage tank and an internal pressure in the upper part of the tank, The processing apparatus includes a storage unit that stores information regarding the installation position of the pressure sensor with respect to the liquid storage tank, and also includes output information from the tilt angle sensor and information regarding the installation position of the pressure sensor that is stored in the storage unit. And a pressure correction processing unit for calculating and correcting the pressure obtained from the pressure sensor, and based on the corrected pressure, To constitute a liquid carrier vehicle such as vacuum truck having a capacity calculation processing unit for calculating the volume of the inner.

In particular, it is preferable to connect a pipe for detecting the internal air pressure in the upper part of the tank to the position of the overflow safety valve provided in the liquid storage tank, and to provide a drain tank in the middle of the pipe for detecting the internal air pressure in the upper part of the tank Is preferred.

  Further, the capacity calculation processing unit of the arithmetic processing unit calculates the fluctuation of the pressure sensor output generated by the liquid level fluctuation in the liquid storage tank during the liquid collection and delivery, and obtains the median amplitude of the liquid level fluctuation to obtain the stationary liquid level Non-linearity between the liquid level in the liquid storage tank and the pressure sensor output generated by the shape of the liquid storage tank, and the liquid level is calculated by the input from the tilt angle sensor. What consists of a net capacity | capacitance calculation process part which estimates the net capacity | capacitance in consideration of the inclination of a conveyance vehicle is preferable.

Further, the present invention is based on the information from the liquid storage tank, the pressure sensor for detecting the stored liquid pressure provided in the vicinity of the bottom of the liquid storage tank, the weight sensor provided in the hose winding unit, and the pressure sensor. In addition to estimating the tank capacity , based on information from the weight sensor, an arithmetic processing unit that estimates the remaining amount of liquid in the hose wound around the hose winding unit or the amount of change thereof , and an inclination capable of detecting the inclination angle of the tank An angle sensor, and the arithmetic processing unit has a storage unit that stores information regarding an installation position of the pressure sensor with respect to the liquid storage tank, and stores output information from the tilt angle sensor and the storage unit. Based on the information on the installation position of the pressure sensor, a pressure correction process for calculating and correcting the pressure obtained from the pressure sensor. Has a section, on the basis of the corrected pressure also provides a liquid carrier vehicle such as vacuum truck having a capacity calculation processing unit for calculating the capacity of the tank.

Further, the present invention is based on the information from the liquid storage tank, the pressure sensor for detecting the stored liquid pressure provided in the vicinity of the bottom of the liquid storage tank, the weight sensor provided in the hose winding unit, and the pressure sensor. Estimates the capacity of the tank and, based on the information from the weight sensor, calculates the remaining amount of liquid in the hose wound around the hose winder or its change amount, and detects the tilt angle of the tank An inclination angle sensor capable of resetting the output from the pressure sensor using a liquid transport vehicle such as a vacuum car having a storage unit for storing information on the installation position of the pressure sensor with respect to the liquid storage tank. Initialization process, output information from the tilt angle sensor, and setting of the pressure sensor stored in the storage unit. Based on the information on the position, the steps of pressure obtained for the operation and correction from said pressure sensor, the corrected and a step of calculating the capacity of the tank on the basis of the pressure, the calculated tank inner volume and the computed hose There is also provided a liquid collection and distribution amount measuring method comprising a collection and distribution amount determination step of determining a collection and distribution amount based on the remaining amount of liquid or its change amount .

  According to the present invention as described above, an inclination angle sensor capable of detecting the inclination angle of the tank is provided, information regarding the installation position of the pressure sensor with respect to the liquid storage tank is stored by the arithmetic processing unit, and output information from the inclination angle sensor And a pressure correction processing unit that calculates and corrects the pressure obtained from the pressure sensor based on the stored information on the installation position of the pressure sensor, so that the correction was made even when the transport vehicle is tilted. The capacity in the tank can be calculated more accurately based on the pressure, and a more accurate collection amount can be charged to the customer.

  Further, according to the present invention, the pressure sensor can be provided at a free position away from the tank via piping or the like without making a hole in the tank body, and a large pressure error is caused by the inclination of the transport vehicle. However, it is possible to correct this and calculate the exact stored fluid pressure to accurately derive the tank capacity, so that the degree of design freedom increases, the cost can be reduced, and intrusion and corrosion problems also occur. Can be resolved.

  In addition, since the pressure sensor is a differential pressure sensor that detects the differential pressure between the liquid pressure due to the liquid stored in the liquid storage tank and the internal air pressure in the upper part of the tank, such as a vacuum car such as filth that greatly changes the internal air pressure Even in this case, the tank capacity can be accurately calculated without error.

  In addition, since the pipe for detecting the internal air pressure in the upper part of the tank is connected to the position of the overflow safety valve provided in the liquid storage tank, it is possible to prevent the entry of dirt and liquid and avoid the situation that the dirt is clogged and cannot be measured.

  Further, since the drain tank is provided in the middle of the pipe for detecting the internal air pressure, it is possible to prevent the pressure sensor from being adversely affected by discharging it even if the air in the pipe is condensed and liquefied due to the temperature.

  In addition, the volume calculation processing unit of the processing unit calculates the fluctuation of the pressure sensor output caused by the liquid level fluctuation in the liquid storage tank during liquid collection and delivery, and calculates the median amplitude of the liquid level fluctuation to determine the stationary liquid level. Non-linearity between the liquid level in the liquid storage tank and the pressure sensor output generated by the estimated liquid level calculation processing unit and the shape of the liquid storage tank is calculated and corrected. The net volume calculation processing unit that estimates the net volume in consideration of the tilt of the liquid level allows the liquid level to be calculated quickly and accurately even while the liquid level is fluctuating. It is possible to calculate an accurate capacity considering the inclination of the transport vehicle. Here, the tilt angle sensor also serves as the tilt angle sensor for calculating and correcting the pressure, which is the pressure sensor output, and the sensor output can be used as it is, so that the cost can be reduced.

  In addition, a liquid transport vehicle such as a vacuum car has a weight sensor in the hose winding unit and, based on information from the weight sensor, a remaining amount of liquid in the hose wound in the hose winding unit or a change amount thereof. An operation processing device for calculating, and the collection and distribution amount determination step determines the collection and distribution amount based on the tank capacity and the calculated liquid remaining amount in the hose or the change amount thereof, so that it does not enter the tank. Considering the remaining amount in the hose, it is possible to request a more accurate collection amount for each house.

The conceptual diagram which shows the liquid transport vehicle which concerns on typical embodiment of this invention. The block diagram which shows the structure of an arithmetic processing unit. Explanatory drawing which shows the structure of a pressure sensor. The conceptual diagram which shows the liquid transport vehicle which concerns on the modification which provided the weight sensor in the hose winding-up part. The block diagram which shows the structure of the arithmetic processing unit which similarly concerns on a modification.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a liquid transport vehicle 1 according to the present invention includes a liquid storage tank 2, a stored pressure sensor 3 for detecting a stored liquid pressure provided near the bottom of the liquid storage tank 2, and a pressure sensor 3. Based on the information, an arithmetic processing unit 4 for estimating the tank internal capacity and an inclination angle sensor 5 capable of detecting the inclination angle of the tank are provided. In the following embodiment, an example in which a vacuum car is configured as the liquid transport vehicle 1 is shown, but the present invention is not limited to this.

  As the pressure sensor 3, a piezoelectric type using a piezo effect, a type using a diaphragm, a semiconductor pressure sensor in which a strain gauge and a diaphragm are integrated, and other general pressure sensors can be widely used. In this example, as shown in FIG. 3, it is a differential pressure sensor that detects a differential pressure between a liquid pressure P1 (bottom liquid pressure) due to liquid stored in the liquid storage tank 2 and an internal pressure P2 inside the tank. The direct differential pressure sensor that guides the pressure pipe 30 to the pressure sensor 3 is illustrated, but the fluid pressure and the internal atmospheric pressure such as a diaphragm seal type differential pressure sensor are detected by separate sensors to electrically detect the difference. It is also possible to use various other differential pressure sensors.

  The pipe 30 for detecting the internal atmospheric pressure P2 is connected to the position of the overflow safety valve 20 provided in the liquid storage tank 2, and extends from there to the position of the pressure sensor 3. The overflow safety valve 20 is such that when the collected amount exceeds the tank capacity, the float part is raised by the collected liquid and the safety valve operates so that the liquid does not spill. During normal operation below the tank capacity, the valve is in close contact with the tank. In order to prevent the operation from deteriorating, it is floated by a claw so that the internal pressure P2 can be removed. Therefore, the internal pressure P2 can be detected by connecting the pipe 30.

  By connecting to the position of the overflow safety valve 20 in this way, it is possible to reliably prevent liquid and foreign matter from entering the pipe 30 during normal operation. In the middle of the pipe 30, a drain tank 31 is provided as a countermeasure against condensation when the gas in the pipe 30 is condensed due to temperature and is liquefied, and is configured to collect the liquefied liquid.

  As shown in FIG. 2, the arithmetic processing unit 4 is a computer including a processing unit 40 and a storage unit 41. The processing unit 40 includes a pressure sensor 3 and an inclination angle sensor 5 that amplify the sensor output or A Connected via a converter (not shown) for / D conversion, and further connected to a display device 6 for outputting the calculation result. The processing device 40 is mainly configured by a CPU such as a microprocessor, and has a storage unit including a RAM and a ROM (not shown), and stores programs and processing data for defining procedures of various processing operations. The arithmetic processing unit 4 may be composed of a plurality of computers other than those composed of a single computer.

  The storage means 41 includes hard disks and the like inside and outside the computer, and includes at least a position information storage unit 41 a that stores information related to the installation position of the pressure sensor 3 with respect to the liquid storage tank 2. Of course, the storage means 41 includes a case where the storage means 41 is stored in a temporary storage area other than the hard disk or the like.

  The processing device 40 functionally includes a pressure correction processing unit 40a that calculates and corrects the pressure obtained from the pressure sensor 3, a capacity calculation processing unit 40b that calculates the capacity in the tank based on the corrected pressure, At least a quantitative processing unit 40c for determining the collection and delivery amount based on the determined capacity, and a display processing unit 40d for outputting the calculated capacity and the quantified collection and delivery amount to the display device 6. These functions are provided by the above program. Realized.

  The pressure correction processing unit 40a corrects the pressure obtained by the pressure sensor 3 based on the output information from the inclination angle sensor 5 and the information on the installation position of the pressure sensor 3 stored in the position information storage unit 41a. It is. Specifically, the installation position of the pressure sensor 3 stored in the position information storage unit 41a includes the shift amount a from the bottom surface of the tank in FIG. 1 to the lower side in the vertical direction, and the tank inner wall (rear wall in this example). The pressure correction processing unit 40a performs pressure correction using the shift amounts a and b and the inclination angle of the vehicle from the inclination angle sensor 5 to the outer side (horizontal rearward in this example). The installation position of the pressure sensor 3 differs depending on the type of tank or vehicle, but can be dealt with by previously storing the shift amount in the position information storage unit 41a.

  Since the pressure is simply increased by the height of a, the shift amount a is corrected to be lower. The amount of deviation b is not affected if the vehicle is horizontal, but if the vehicle is tilted forward by an angle θ (in the case of processing in the middle of an uphill, for example), the height is approximately b × tan θ. Since the pressure increases by the amount, it is corrected so as to decrease. In this example, since the pressure sensor 3 is provided at the center position in the tank width direction, correction is not necessary. However, if the pressure sensor 3 is shifted left and right, the amount of shift and the inclination angle of the vehicle to the left and right are considered. It is preferable to correct. Although an example of correction is shown in this example, the correction method may be other methods.

  The pressure sensor 3 of the representative example is a direct type example that guides the pipe for guiding pressure to the differential pressure sensor, and corrects after taking the differential pressure (output of the differential pressure sensor), but it does not have a pipe such as a diaphragm seal type. In the case of a method in which the hydraulic pressure and the internal atmospheric pressure are detected by a separate sensor and an electrical difference is taken, correction may be made after taking the differential pressure, or only the sensor output on the hydraulic pressure side may be corrected.

  As the capacity calculation processing unit 40b, the same processing unit as described in JP-A-7-189333 can be used, and the output (correction value) of the pressure sensor 3 generated by the liquid level fluctuation in the liquid storage tank 2 at the time of liquid collection and delivery. ) And calculating the median amplitude of the liquid level fluctuation to estimate the static liquid level, and the liquid amount and pressure in the liquid storage tank 2 generated by the shape of the liquid storage tank 2 A net capacity calculation processing unit 402b that calculates and corrects non-linearity with the sensor 3 output (correction value) and estimates the net capacity in consideration of the inclination of the liquid transport vehicle 1 by the input from the tilt angle sensor 5. It is configured.

  The static liquid level calculation processing unit 401 b estimates the static liquid level in the storage tank 2, and determines the liquid level in the liquid storage tank 2 based on the detection output after correction of the pressure sensor 3. Specifically, the fluctuation of the output (correction value) from the pressure sensor 3 caused by the fluctuation of the liquid level is recognized and the center of the amplitude is calculated as a stationary liquid level, and even if the liquid level fluctuates immediately after pumping, The amount of pumping can be quantified by quickly estimating the static liquid level.

  The net capacity calculation processing unit 402b is a liquid transport vehicle based on a non-linearity correction function between the liquid amount due to the shape of the liquid storage tank 2 and the output (correction value) of the pressure sensor 3 and the input from the tilt angle sensor 5. 1 tilt correction function. This is caused by the shape of the liquid storage tank 2 and the parking state of the vacuum car. Using the shape element of the liquid storage tank 2, the amount of stored liquid is related to the detected pressure (correction value) corresponding to the liquid level, and the net capacity is estimated. Specifically, the method described in the above publication may be applied.

  And the liquid collection and delivery amount measuring method according to the present invention uses the above-described liquid transport vehicle 1 to reset and initialize the output of the pressure sensor 3, and to store the output information from the tilt angle sensor 5 and the storage unit. The pressure correction processing unit 40a of the arithmetic processing unit 4 calculates and corrects the pressure obtained from the pressure sensor 3 based on the information regarding the installation position of the pressure sensor 3, and the static liquid level calculation processing based on the corrected pressure. The volume calculation processing unit 40b of the calculation processing device 4 including the unit 401b and the net capacity calculation processing unit 402b calculates the capacity in the tank, and the quantitative processing unit 40c of the calculation processing device 4 based on the calculated tank internal capacity. Is composed of a collection and distribution amount determination step for determining the collection and distribution amount. Data output for each process, for example, the calculated tank capacity and collection / delivery amount, is output to the display device 6 so that the customer can check it.

  FIG. 4 shows a modification in which the weight sensor 7 is provided in the hose winding part 10 of the liquid transport vehicle 1. When the hose 11 for storing the liquid in the liquid storage tank 2 is provided, usually a hose winding unit 10 such as a winding drum for winding the hose is provided. For example, in a vacuum car, a long hose may be close to 100 m, the remaining amount remaining in the hose without being stored in the tank increases, and the variation in the remaining amount varies depending on the worker. Therefore, the error due to the remaining amount in the hose may be added to the collected amount of another customer (the next customer or the like).

  Therefore, as in this modification, a single or a plurality of weight sensors 7 (for example, load cells) are provided in the hose winding unit 10 so that the combined weight of the hose winding unit 10 and the hose 11 wound on the hose winding unit 10 can be measured. By configuring, it is preferable to configure so that a more accurate collection amount can be requested for each house, taking into account the remaining amount of liquid in the hose 11 or the amount of change thereof in the tank capacity. .

  As an example of a specific calculation method, as shown in FIG. 5, for example, the processing device 40 of the calculation processing device 4 further includes a remaining amount change calculation processing unit 40e for calculating the amount of change in the remaining amount of the hose. The storage means 41 includes a hose remaining amount storage unit 41b that stores the remaining amount of hose, and the remaining amount change calculation processing unit 40e includes information from the weight sensor 7 and the previous hose remaining amount stored in the hose remaining amount storage unit 41b. The amount of increase / decrease in the remaining amount of the hose is obtained based on the amount, and the quantitative processing unit 40c determines the collection / delivery amount based on the increase / decrease amount and the capacity in the tank calculated by the capacity calculation processing unit 40b. Of course, the remaining amount change may be calculated by an arithmetic processing device different from the arithmetic processing device 4.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. For example, it can be applied not only for collection work such as urine collection but also for liquid metering. That is, in collection work such as human waste processing, the pre-collection output is subtracted from the post-collection output of the pressure sensor and weighed. In the delivery work, after delivery of an arbitrary amount, the post-collection output is subtracted from the pre-collection output. What is necessary is to provide a function of measuring the amount or subtracting the predetermined delivery amount from the output before collection and stopping the supply as soon as the predetermined amount is reached.

DESCRIPTION OF SYMBOLS 1 Liquid transport vehicle 2 Liquid storage tank 3 Pressure sensor 4 Arithmetic processing device 5 Inclination angle sensor 6 Display device 7 Weight sensor 10 Hose winding part 11 Hose 20 Safety valve 30 Piping 31 Drain tank 40 Processing apparatus 40a Pressure correction processing part 40b Capacity calculation Processing unit 40c Fixed amount processing unit 40d Display processing unit 40e Remaining amount change calculation processing unit 41 Storage means 41a Position information storage unit 401b Still liquid level calculation processing unit 402b Net volume calculation processing unit 41b Remaining amount storage unit P1 Hydraulic pressure P2 Internal pressure

Claims (6)

A liquid storage tank, a pressure sensor for detecting a stored liquid pressure provided in the vicinity of the bottom of the liquid storage tank, an arithmetic processing unit for estimating the tank capacity based on information from the pressure sensor, and detecting a tilt angle of the tank With a tilt angle sensor that can
The pressure sensor is a differential pressure sensor for detecting a differential pressure between the liquid pressure of the liquid stored in the liquid storage tank and the internal pressure of the upper part of the tank;
The arithmetic processing unit is
While having a storage unit for storing information on the installation position of the pressure sensor with respect to the liquid storage tank,
Based on output information from the tilt angle sensor and information on the installation position of the pressure sensor stored in the storage unit, a pressure correction processing unit for calculating and correcting the pressure obtained from the pressure sensor,
A liquid transport vehicle such as a vacuum car having a capacity calculation processing unit that calculates the capacity in the tank based on the corrected pressure. A pipe for detecting the internal pressure in the upper part of the tank, formed by connecting the position of the overflow safety valve provided in the liquid storage tank according to claim 1 liquid truck according. 3. The liquid transport vehicle according to claim 1, wherein a drain tank is provided in the middle of the pipe for detecting the internal air pressure in the upper part of the tank. The capacity calculation processing unit of the calculation processing device is
A static liquid level calculation processing unit that calculates the fluctuation of the pressure sensor output generated by the liquid level fluctuation in the liquid storage tank during liquid collection and distribution, calculates the median amplitude of the liquid level fluctuation, and estimates the static liquid level;
Non-linearity between the liquid volume in the liquid storage tank and the pressure sensor output generated by the shape of the liquid storage tank is calculated and corrected, and the net capacity is calculated by taking into account the inclination of the liquid transport vehicle by the input from the tilt angle sensor. the more the net capacity calculation processing section for estimating the claims 1 liquid carrier vehicle according to any one of 3. Based on the information from the liquid storage tank, the pressure sensor for detecting the stored liquid pressure provided in the vicinity of the bottom of the liquid storage tank, the weight sensor provided in the hose winding unit, and the information from the pressure sensor, the capacity in the tank is estimated. And an arithmetic processing unit that estimates the remaining amount of liquid in the hose wound around the hose winding part or the amount of change based on information from the weight sensor, and an inclination angle sensor that can detect the inclination angle of the tank. ,
The arithmetic processing unit is
While having a storage unit for storing information on the installation position of the pressure sensor with respect to the liquid storage tank,
Based on output information from the tilt angle sensor and information on the installation position of the pressure sensor stored in the storage unit, a pressure correction processing unit for calculating and correcting the pressure obtained from the pressure sensor,
A liquid transport vehicle such as a vacuum car having a capacity calculation processing unit that calculates the capacity in the tank based on the corrected pressure. Based on the information from the liquid storage tank, the pressure sensor for detecting the stored liquid pressure provided in the vicinity of the bottom of the liquid storage tank, the weight sensor provided in the hose winding unit, and the information from the pressure sensor, the capacity in the tank is estimated. And an arithmetic processing unit that calculates the remaining amount of liquid in the hose wound around the hose winding part or the amount of change based on the information from the weight sensor, and an inclination angle sensor that can detect the inclination angle of the tank, Using a liquid transport vehicle such as a vacuum car having a storage unit that stores information related to the installation position of the pressure sensor with respect to the liquid storage tank.
Resetting and initializing the output from the pressure sensor;
Calculating and correcting the pressure obtained from the pressure sensor based on the output information from the tilt angle sensor and the information on the installation position of the pressure sensor stored in the storage unit;
Calculating a capacity in the tank based on the corrected pressure;
A liquid collection / distribution metering method comprising: a collection / distribution amount determination step of determining a collection / delivery amount based on the calculated tank internal capacity and the calculated liquid remaining amount in the hose or its change amount .

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