JP6067073B1 - Mixer - Google Patents

Abstract

The present invention provides a mixer capable of satisfactorily obtaining a slump value of ready-mixed concrete stirred by a mixer. A mixer 10J includes a mixer drum 10, an electrode 11, and a calculation unit 12. The mixer drum 10 has a rotating shaft 10G that extends in the lateral direction, and ready-mixed concrete is charged with a space left on the upper side. The electrode 11 is provided in the mixer drum 10, and moves along a predetermined circumference around the rotation shaft 10 </ b> G of the mixer drum 10 as the mixer drum 10 rotates to measure the resistance value. The calculation unit 12 obtains a slump value corresponding to the rotation speed of the mixer drum 10 and the resistance change speed measured using the electrode 11. [Selection] Figure 2

Description

  The present invention relates to a mixer.

  Patent Document 1 discloses a conventional mixer. This mixer includes a mixer drum, three types of electrodes, and a calculation unit. The mixer drum is provided with an opening having one end opened. Further, this mixer drum has a closed end at the other end in the back direction when viewed from one end. Each electrode is provided on the inner peripheral surface of the mixer drum. Each of the electrodes can measure the pressure that the inner peripheral surface of the mixer drum receives from the ready-mixed concrete, the moisture content and the temperature of the ready-mixed concrete. Each electrode is connected to the calculation unit. The calculation unit obtains a slump value from each measurement value measured by each electrode. For this reason, this mixer can obtain | require a slump value, stirring ready mixed concrete with a mixer drum.

US Patent Application Publication No. 2011/0077778

  However, the mixer of Patent Document 1 is provided with three types of electrodes in order to measure the pressure that the inner peripheral surface of the mixer drum receives from the ready-mixed concrete, the moisture content of the ready-mixed concrete, and the absolute value of the temperature. For this reason, this mixer appropriately measures the absolute value of the pressure, the amount of moisture and the temperature of the ready-mixed concrete that the inner peripheral surface of the mixer drum receives from the ready-mixed concrete when it is cured with the ready-mixed concrete attached to each electrode. There is a risk that it will not be possible. For this reason, this mixer may not be able to obtain an accurate slump value.

  This invention is made | formed in view of the said conventional situation, Comprising: It is set as the problem which should be solved to provide the mixer which can obtain | require the slump value of the ready mixed concrete stirred with a mixer drum favorably.

  The mixer of the present invention includes a mixer drum, an electrode, and a calculation unit. The mixer drum has a rotating shaft extending in the lateral direction. The mixer drum is filled with ready-mixed concrete leaving a space on the upper side. The electrode is provided in the mixer drum. The electrode moves along a predetermined circumference around the rotation axis of the mixer drum as the mixer drum rotates, and measures predetermined electrical characteristics. The calculation unit obtains a slump value corresponding to the rotational speed of the mixer drum when the ready-mixed concrete is agitated and the change speed of the electrical characteristics measured using the electrodes at that time.

  As described above, when the slump value is obtained, the mixer only has to measure the change rate of the predetermined electrical characteristic using one type of electrode, and therefore, it is not necessary to provide a plurality of types of electrodes. In addition, the mixer obtains the slump value by using a change rate of a predetermined electric characteristic. Even if this mixer is hardened with ready mixed concrete adhering to the electrode and has an influence on the measured absolute value of the predetermined electric characteristic, it hardly affects the rate of change of the predetermined electric characteristic. For this reason, this mixer can obtain the slump value without being affected by the state around the electrode.

  Therefore, the mixer of this invention can obtain | require the slump value of the ready mixed concrete stirred with a mixer drum favorably.

  In the mixer of the present invention, the calculation unit can obtain the change rate of the electrical characteristics from the time when the electrical characteristics measured using the electrodes change from the minimum value to the maximum value, or the time when the electrical characteristics change from the maximum value to the minimum value. In this case, since this mixer can easily measure the minimum value and the maximum value of the predetermined electric characteristic using the electrodes, the change rate of the predetermined electric characteristic can be easily obtained.

  In the mixer of the present invention, the calculation unit can obtain the rotation speed of the mixer drum from one cycle of the electrical characteristics measured using the electrodes. In this case, since this mixer can measure the rotation speed of the mixer drum using an electrode for obtaining a change speed of a predetermined electric characteristic, it is not necessary to separately provide a tachometer or the like.

  In the mixer according to the present invention, the recording unit records a rotation speed of the mixer drum, a change speed of the electric characteristics, and a database storing a slump value obtained from the rotation speed and the change speed. In addition, the calculation unit can obtain the slump value from the database stored in the recording unit. In this case, the mixer uses the electrodes to measure the rotation speed of the mixer drum and the change speed of the electric characteristics, and makes those values correspond to the rotation speed of the mixer drum recorded in the recording unit and the change speed of the electric characteristics. Thus, the slump value can be easily obtained.

  The mixer of the present invention can measure the rate of change in electrical characteristics from when the electrode is buried in ready-mixed concrete until it is exposed to the space above the ready-mixed concrete. In this case, when the mixer drum rotates, the loaded ready-mixed concrete is lifted along the inner peripheral surface of the mixer drum. As a result, the time taken for the electrode that rotates with the rotation of the mixer drum to be exposed to the space above the ready-mixed concrete from the ready-mixed concrete is taken from the space above the ready-mixed concrete until it is buried in the ready-mixed concrete. Longer than time. In other words, since this mixer can measure the side where the electrical characteristics change for a long time, the change speed of the electrical characteristics can be obtained more accurately.

It is the schematic which shows the mixer truck of Embodiment 1. FIG. (A) is a schematic diagram of a mixer drum, and (B) is an enlarged view of a main part in which a portion where each electrode unit, calculation unit, and recording unit are arranged is enlarged. (A) It is arrow XX sectional drawing shown in FIG. 2, (B) is the principal part enlarged view which expanded the part by which each electrode part, the calculating part, and the recording part are arrange | positioned. It is a graph which shows the time change of the resistance value measured using each electrode when the mixer drum rotated in order to stir the ready mixed concrete thrown into the mixer drum of Embodiment 1. FIG. 3 is a flowchart illustrating steps for determining a maximum value and a minimum value from resistance values measured using the respective electrodes according to the first embodiment. It is a flowchart which shows the step which calculates | requires the rotation speed of a mixer drum, and the change speed of resistance value from the resistance value measured using each electrode of Embodiment 1, and calculates | requires the slump value of ready mixed concrete. It is a schematic diagram which shows the part by which the electrode of Embodiment 2, the calculating part, and the recording part are arrange | positioned. It is a graph which shows the time change of the electrostatic capacitance value measured using each electrode when the mixer drum rotated in order to stir the ready mixed concrete thrown into the mixer drum of Embodiment 2. FIG.

Next, Embodiments 1 and 2 embodying a mixer vehicle in which the mixer of the present invention is mounted on a vehicle body frame will be described with reference to the drawings.
<Embodiment 1>
As shown in FIG. 1, the mixer vehicle of the first embodiment includes a vehicle body 50, a hopper 50C, a chute 50D, and a mixer 10J.

  The vehicle body 50 includes a cabin 50A and a frame 50B. The cabin 50A is provided on the front side of the vehicle body 50 (front and rear are the left and right in FIG. 1, the same applies hereinafter). The frame 50B is provided on the upper side of the gantry 50F provided on the rear side of the cabin 50A. The engine (not shown) drives the vehicle body 50 and is provided below the cabin 50A (upper and lower are upper and lower in FIG. 1; the same applies hereinafter).

  The hopper 50 </ b> C is formed with an input port that opens while expanding upward. The lower end of the hopper 50C is opened in the front lower direction, and a discharge port is formed. The hopper 50C communicates with a central portion of an opening 10E of the mixer drum 10 which will be described later. The hopper 50C is fixed to the upper part of the rear end portion of the frame 50B. The hopper 50C puts the ready-mixed concrete thrown into the inlet into the mixer drum 10 from the outlet.

  The chute 50D is supported at the rear end portion of the frame 50B so that the front end portion thereof is rotatable in the horizontal direction and the vertical direction with the base end portion as the center. The horizontal direction does not necessarily mean a strict horizontal direction, but includes a state slightly deviated from the strict horizontal direction. Thus, the chute 50D guides the ready-mixed concrete discharged from the mixer drum 10 to a desired position.

  The mixer 10J includes a mixer drum 10, two electrodes 11, a calculation unit 12, a recording unit 13, and a power supply unit 14, as shown in FIGS. 2 (A) and 2 (B) and FIGS. 3 (A) and 3 (B). ing.

  The mixer drum 10 includes a drum body 10A, a drive shaft 10B, two drum blades 10C, and a roller ring 10D. The drum body 10A has a cylindrical shape. The drum main body 10A is provided with an opening 10E having one end opened. Further, the drum body 10A is closed at the other end in the back direction when viewed from one end by a closing portion 10F. The drive shaft 10B is connected to the center of the closing portion 10F and extends outward from the drum body 10A. The drive shaft 10 </ b> B extends on the rotation shaft 10 </ b> G of the mixer drum 10.

  The drive shaft 10B is connected to a speed reducer (not shown). The speed reducer is connected to a hydraulic motor (not shown). The hydraulic motor is connected to a hydraulic pump (not shown) via a pipe (not shown). The hydraulic pump is connected to a vehicle engine (not shown). Thus, the rotational force of the engine is transmitted to the drive shaft 10B via the hydraulic pump, piping, hydraulic motor, and speed reducer to rotate the mixer drum 10.

  Each drum blade 10C is spirally fixed along the inner peripheral surface of the drum main body 10A at a predetermined interval. That is, the drum blade 10C rotates with the drum body 10A. The roller ring 10D has an annular shape and is provided so as to go around the outer peripheral surface of the drum body 10A on the opening 10E side.

  As shown in FIG. 1, the mixer drum 10 is rotatably mounted on the frame 50 </ b> B in a forward tilt posture in which the opening 10 </ b> E is positioned above and the opening 10 </ b> E is lifted above the closing portion 10 </ b> F. Specifically, the mixer drum 10 is supported from below by a plurality of rollers 50E, in which a roller ring 10D is rotatably provided at the upper portion of the rear end of the frame 50B. That is, the mixer drum 10 is rotatably mounted on the frame 50B with the rotation shaft 10G inclined and extending in the lateral direction.

  As shown in FIGS. 2A and 2B and FIGS. 3A and 3B, each electrode 11 can measure a resistance value that is a predetermined electrical property between each other. Each electrode 11 extends in a columnar shape and is provided at the front and rear intermediate portions of the inner peripheral surface of the mixer drum 10, which is inside the mixer drum 10. Specifically, the electrodes 11 are arranged in the front-rear direction of the mixer drum 10 with a predetermined interval therebetween. Each electrode 11 is provided with its base end in contact with the inner peripheral surface of the mixer drum 10 and with its tip facing the rotating shaft 10G of the mixer drum 10. Each electrode 11 is provided such that its center line 11A is perpendicular to the rotation axis 10G of the mixer drum 10. That is, each electrode 11 is provided such that its center line 11A is parallel to each other. As shown in FIG. 2B, the electric wires 15 are connected to the base ends of the respective electrodes 11 through through holes that are watertightly penetrated on the side surfaces of the mixer drum 10.

  The calculation unit 12 and the recording unit 13 are provided on the outer peripheral surface of the mixer drum 10. The calculation unit 12 and the recording unit 13 are arranged next to each other and are electrically connected to each other. The calculation unit 12 and the recording unit 13 are provided in the middle of each electrode 11. The other end of the electric wire 15 is electrically connected to the calculation unit 12. The power supply unit 14 is provided on the outer peripheral surface of the mixer drum 10. The power supply unit 14 is provided adjacent to the calculation unit 12 and the recording unit 13. The power supply unit 14 is connected to the calculation unit 12 via an electric wire 16. The calculation unit 12 obtains power necessary for operation from the power supply unit 14 via the electric wire 16. Further, each electrode 11 and the recording unit 13 obtain power necessary for operation from the power supply unit 14 via the electric wire 16 and the calculation unit 12. The recording unit 13 is a ROM, a flash memory, or the like, and can record a database to be described later.

  Next, the operation of the mixer 10J of this mixer vehicle will be described. The mixer 10J extends in the lateral direction with the rotation shaft 10G inclined. For this reason, when ready-mixed concrete is introduced into the mixer drum 10, a space is left above the ready-mixed concrete. The mixer 10J agitates the ready-mixed concrete put into the mixer drum 10 by rotating around the rotating shaft 10G.

  Each electrode 11 provided on the inner peripheral surface of the mixer drum 10 rotates the mixer drum 10 on the circumference (predetermined circumference) in the vicinity of the inner peripheral surface of the mixer drum 10 around the rotation shaft 10G of the mixer drum 10. Move with it. Thus, each electrode 11 enters and exits between the ready-mixed concrete put into the mixer drum 10 and the space left above the ready-mixed concrete.

  As shown in FIG. 4, the resistance value becomes the minimum value Min1 while each electrode 11 is completely buried in the ready-mixed concrete (T1 to T2), and each electrode 11 is on the upper side of the ready-mixed concrete. The maximum value Max1 is reached during the movement (T3 to T4) in a state where the space is completely exposed. Also, this resistance value is directed from the minimum value Min1 to the maximum value Max1 during the period from the state where each electrode 11 is completely buried in the readymixed concrete until it is completely exposed to the space above the readymixed concrete (T2 to T3). Gradually rise. Also, this resistance value is from the maximum value Max1 to the minimum value Min1 from the state in which each electrode 11 is completely exposed in the space above the readymixed concrete until it is completely buried in the readymixed concrete (T4 to T5). Gradually descend toward In other words, this resistance value periodically changes between the minimum value Min1 and the maximum value Max1 as each electrode 11 moves on the circumference in the vicinity of the inner peripheral surface of the mixer drum 10 as the mixer drum 10 rotates. That is, this resistance value has one cycle of T1 to T5. This means that the mixer drum 10 has made one revolution in this one cycle.

  Next, a method for obtaining the slump value will be described. The slump value is a value representing the fluidity of ready-mixed concrete. The slump value increases when the amount of moisture in the ready-mixed concrete is large, and decreases when the amount of moisture is small.

  For example, when the slump value is large (the fluidity is high), the ready-mixed concrete does not easily stick to the inner peripheral surface of the mixer drum 10 and each electrode 11. Specifically, ready-mixed concrete is difficult to stick along the inner peripheral surface of the mixer drum 10 even if the rotational speed of the mixer drum 10 is high (even if the interval between T1 to 15 is short), and is lifted along the inner peripheral surface of the mixer drum 10 It's hard to be done. For this reason, the distance that each electrode 11 moves in the ready-mixed concrete is shortened. In addition, the ready-mixed concrete does not easily stick to each electrode 11, and each electrode 11 easily moves in the ready-mixed concrete in a short time. For these reasons, as the slump value of ready-mixed concrete increases, the rate of change of the resistance value increases (the interval between T2 and T3 decreases).

  Conversely, when the slump value is small (low fluidity), the ready-mixed concrete tends to stick to the inner peripheral surface of the mixer drum 10 and each electrode 11. Specifically, ready-mixed concrete tends to stick along the inner peripheral surface of the mixer drum 10 when the rotation speed of the mixer drum 10 is fast (short between T1 and T15), and is easily lifted along the inner peripheral surface of the mixer drum 10. . For this reason, the distance that each electrode 11 moves in the ready-mixed concrete becomes long. Also, ready-mixed concrete tends to stick to each electrode 11, and each electrode 11 is difficult to move in the ready-mixed concrete in a short time. For these reasons, when the slump value of ready-mixed concrete is reduced, the rate of change of the resistance value is reduced (between T2 and T3 is increased).

  Thus, the slump value affects the rotational speed of the mixer drum 10 (hereinafter referred to as “rotational speed”) and the change rate of the resistance value (hereinafter referred to as “change speed”) depending on the magnitude thereof. Table 1 shows the rotation speed obtained from the experiment and the slump value corresponding to the change speed. The recording unit 13 records a database that stores slump values corresponding to the rotation speed and the change speed.

  The rotational speed when the ready-mixed concrete is agitated by rotating the mixer drum 10 is a periodically changing resistance value measured using each electrode 11 that moves as the mixer drum 10 rotates, as shown in FIG. Is the reciprocal of one cycle (T1 to T5). That is, the rotation speed is obtained by the calculation unit 12 from one period (T1 to T5) of the resistance value measured using each electrode 11.

  The rate of change is the time when the periodically changing resistance value measured using each electrode 11 that moves with the rotation of the mixer drum 10 starts to rise from the minimum value Min1 (T2) and reaches the maximum value Max1 ( Time until T3) (T2 to T3). That is, for the change speed, the calculation unit 12 obtains the time (T2 to T3) during which the resistance value measured using each electrode 11 changes from the minimum value Min1 to the maximum value Max1. That is, the change rate of the resistance value from the state in which each electrode 11 is completely buried in the ready-mixed concrete until it is completely exposed to the space above the ready-mixed concrete is measured. Thus, the rotation speed and the change speed can be obtained by the calculation unit 12 from the resistance value measured using each electrode 11.

  A slump value corresponding to the rotation speed and change speed obtained by the computing unit 12 is obtained by the computing unit 12 from a database recorded in the recording unit 13. For example, as shown in Table 1, the slump value of ready-mixed concrete when the rotation speed is 1.5 rpm and the change speed is 0.5 seconds is 10 cm.

  Next, the control for determining the minimum value Min1 and the maximum value Max1 from the resistance value measured using each electrode 11 in the calculation unit 12 will be described. The flowchart shown in FIG. 5 is repeatedly calculated by the calculation unit 12 every predetermined time. For this reason, the calculating part 12 can obtain the present resistance value measured using each electrode 11 repeatedly for every predetermined time.

  First, provisional minimum and maximum values are collected from the current resistance values measured using the respective electrodes 11 as the mixer drum 10 rotates (step S1). Specifically, the current resistance value measured using each electrode 11 is compared with the first boundary value and the second boundary value (the first boundary value and the second boundary value are recorded in the recording unit 13 in advance). Yes.) At this time, when the current resistance value is smaller than the first boundary value, it is collected as a provisional minimum value, and when it is larger than the second boundary value, it is collected as a provisional maximum value.

  Next, it is determined whether the provisional minimum and maximum values collected in step S1 are stable (step S2). The calculation unit 12 calculates by repeating the flowchart of FIG. 5 at predetermined time intervals. For this reason, the calculating part 12 can collect a temporary minimum value and maximum value repeatedly for every predetermined time from the present resistance value measured using each electrode 11. Specifically, it is determined whether the difference between the provisional minimum value and the maximum value collected in step S1 is larger than a predetermined value. Further, it is determined whether or not the provisional minimum value and maximum value stay within a predetermined range for a predetermined time (the predetermined value, the predetermined range, and the predetermined time are recorded in the recording unit 13 in advance). .) Thereafter, when it is determined that the provisional minimum and maximum values are stable, the process proceeds to step S3. If it is determined that the temporary minimum value and the maximum value are not stable, the calculation is terminated and the temporary minimum value and the maximum value are collected from the resistance value in the next calculation repeated in the calculation unit 12 again. To do.

  Next, the minimum value Min1 and the maximum value Max1 for comparison are determined (step S3). Specifically, when it is determined in step S2 that the provisional minimum value and maximum value are stable, the provisional minimum value and maximum value are stored as a comparison minimum value Min1 and maximum value Max1.

  Next, the control for obtaining the rotation speed and the change speed in the calculation unit 12 will be described. The flowchart shown in FIG. 6 is repeatedly calculated by the calculation unit 12 every predetermined time. Therefore, the calculation unit 12 repeats the current resistance value measured using each electrode 11 and the comparison minimum value Min1 and maximum value Max1 stored in step S3 (see FIG. 5) at predetermined time intervals. Can be compared.

  First, the current resistance value measured using each electrode 11 with the rotation of the mixer drum 10 is measured (step S11). Next, it is determined whether the current resistance value measured using each electrode 11 has reached a comparison minimum value Min1 (T1) (step S12). If it is determined that the current resistance value measured using each electrode 11 has reached the minimum value for comparison Min1 (T1), the process proceeds to step S13. On the other hand, if it is determined that the current resistance value measured using each electrode 11 does not reach the minimum value Min1 for comparison (T1), the process proceeds to step S14.

  When the process proceeds to step S13, the rotation speed of the mixer 10J of the previous cycle is obtained, and measurement of the rotation speed of the mixer 10J of the next cycle is started. Specifically, every time the flowchart of FIG. 6 is repeatedly calculated by the calculation unit 12 every predetermined time, +1 is accumulated, and when the current resistance value reaches the comparison minimum value Min1 (T1, T5). A first counter is provided that is reset to zero. That is, the first counter is reset to 0 once every time the mixer drum 10 rotates once. For this reason, the rotation speed of the mixer drum 10 is the reciprocal of the result obtained by multiplying the value immediately before the first counter is reset to 0 and the time that the flowchart of FIG. You can ask for it. Then, after the first counter is reset to 0, the integration of +1 is repeated every predetermined time, and the measurement of the rotational speed of the mixer 10J in the next one cycle is started.

  In step S14, it is determined whether the current resistance value has started to rise from the minimum value Min1 for comparison (T2). When it is determined that the current resistance value measured using each electrode 11 is the time point (T2) when the current resistance value starts to increase from the minimum value Min1 for comparison, the process proceeds to step S15. On the other hand, if it is determined that the current resistance value measured using each electrode 11 is not the time (T2) when the current resistance value starts to rise from the minimum value Min1 for comparison, the process proceeds to step S16.

  When the process proceeds to step S15, the measurement of the time until the time point (T3) when the current resistance value measured using each electrode 11 reaches the maximum value Max1 for comparison is started. Specifically, the time (T2 to T3) from the time (T2) when the current resistance value starts to rise from the minimum value Min1 for comparison to the time (T3) when it reaches the maximum value Max1 for comparison, the flowchart of FIG. A second counter is provided in which +1 is added each time the value is repeatedly calculated by the calculation unit 12. That is, integration of +1 to the second counter is started in step S15.

  In step S16, it is determined whether the current resistance value has reached the maximum value Max1 for comparison (T3). When it is determined that the current resistance value measured using each electrode 11 has reached the maximum value Max1 for comparison (T3), the process proceeds to step S17. Further, when it is determined that the current resistance value measured using each electrode 11 is not at the time (T3) when the maximum resistance value Max1 for comparison is reached, the calculation is terminated and the next calculation repeated in the calculation unit again. In step S11.

  When the process proceeds to step S17, the change speed is obtained. Specifically, the time (T3) from the time point (T2) when the current resistance value measured using each electrode 11 starts to rise from the minimum value Min1 for comparison to the time point (T3) when reaching the maximum value Max1 for comparison ( T2-T3) is calculated. That is, the rate of change is obtained by multiplying the current value of the second counter at which the addition of +1 is started in step S15 by the time calculated by the flowchart of FIG. Can do. Then, the second counter is reset to zero.

  Next, a slump value corresponding to the rotation speed and the change speed is obtained (step S18). Specifically, the rotation speed obtained in step S13 and the slump value corresponding to the change speed obtained in step S17 are obtained from the database recorded in the recording unit 13.

  As described above, when the slump value is obtained, the mixer vehicle according to the first embodiment only needs to measure the change rate of the resistance value using one type of electrode 11, and therefore, it is not necessary to provide a plurality of types of electrodes 11. . Further, this mixer vehicle obtains the slump value by using the change rate of the resistance value. Even if the mixed vehicle is cured with the ready-mixed concrete adhering to the electrode 11 and has an influence on the absolute value of the measured resistance value, it hardly affects the rate of change of the resistance value. For this reason, this mixer car can obtain | require a slump value, without being influenced by the surrounding state of the electrode 11. FIG.

  Therefore, the mixer truck of Embodiment 1 can satisfactorily obtain the slump value of ready-mixed concrete that is stirred by the mixer drum 10.

  Further, in this mixer vehicle, the calculation unit 12 obtains the rate of change of the resistance value from the time (T2 to T3) when the resistance value measured using the electrode 11 changes from the minimum value Min1 to the maximum value Max1. For this reason, since this mixer vehicle can easily measure the minimum value Min1 and the maximum value Max1 of the resistance value using the electrode 11, the speed of change of the resistance value can be easily obtained.

  In this mixer vehicle, the calculation unit 12 obtains the rotational speed of the mixer drum 10 from one cycle (T1 to T5) of the resistance value measured using the electrode 11. For this reason, since this mixer vehicle can measure the rotational speed of the mixer drum 10 by using the electrode 11 for obtaining the change speed of the resistance value, it is not necessary to separately provide a tachometer or the like.

  Further, in this mixer vehicle, the recording unit 13 records a database that stores the rotation speed of the mixer drum 10, the change speed of the electrical characteristics, and the slump value obtained from the rotation speed and the change speed. Further, the calculation unit 12 obtains the slump value from the database stored in the recording unit 13. For this reason, this mixer vehicle measures the rotational speed of the mixer drum 10 and the change speed of the electrical characteristics using the electrode 11, and records the values of the rotational speed and electrical characteristics of the mixer drum 10 recorded in the recording unit 13. By making it correspond to the changing speed, the slump value can be easily obtained.

  Moreover, this mixer truck measures the change rate of the electrical characteristics from the state in which the electrode 11 is buried in the ready-mixed concrete until it is exposed to the space above the ready-mixed concrete. For this reason, when the mixer drum 10 rotates, the ready-mixed concrete thrown up is lifted along the inner peripheral surface of the mixer drum 10. Thereby, the time taken for the electrode 11 rotating with the rotation of the mixer drum 10 to be exposed to the space above the ready-mixed concrete from the ready-mixed concrete is until it is buried in the ready-mixed concrete from the space above the ready-mixed concrete. Longer than the time it takes. That is, since this mixer vehicle can measure the side where the electrical characteristics change longer, the speed of change of the electrical characteristics can be obtained more accurately.

<Embodiment 2>
The mixer vehicle of the second embodiment is different from the first embodiment in that the structure of the two electrodes 111 and the capacitance value between these electrodes 111 are measured. Other configurations are the same as those of the first embodiment, and the same configurations as those of the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

  Each electrode 111 includes a conductor portion 60 and an insulating member 61 as shown in FIG. The conductor portion 60 extends in a columnar shape. Each electrode 111 covers the surface of the conductor portion 60 with an insulating member 61 so that the surface of the conductor portion 60 and the ready-mixed concrete do not directly touch each other. Each electrode 111 extends in a columnar shape and is provided at the front and rear intermediate portions of the inner peripheral surface of the mixer drum 10 (not shown). Each electrode 111 is provided with its base end in contact with the inner peripheral surface of the mixer drum 10 and with its tip facing the rotating shaft 10G of the mixer drum 10. Each electrode 111 is provided such that a center line 11 </ b> A is perpendicular to the rotating shaft 10 </ b> G of the mixer drum 10. That is, each electrode 111 is provided such that the respective center lines 11A are parallel to each other.

  As shown in FIG. 8, each electrode 111 can measure the capacitance value between each other. The capacitance value measured using each electrode 111 becomes the minimum value Min2 while each electrode 111 is moving (T13 to T14) in a state in which the space above the ready-mixed concrete is completely exposed, and each electrode 111 Reaches the maximum value Max2 during movement (T11 to T12) in a state where it is completely buried in the ready-mixed concrete. The electrostatic capacitance value is maximized from the minimum value Min2 during the period from when the electrodes 111 are completely exposed in the space above the ready-mixed concrete until they are completely buried in the ready-mixed concrete (T14 to T15). It gradually increases toward the value Max2. Also, this electrostatic capacitance value is from the maximum value Max2 to the minimum value Min2 between the state in which each electrode 111 is completely buried in the readymixed concrete until it is completely exposed to the space above the readymixed concrete (T12 to T13). Gradually descend toward That is, this capacitance value is periodically shifted between the minimum value Min2 and the maximum value Max2 as each electrode 111 moves on the circumference in the vicinity of the inner peripheral surface of the mixer drum 10 as the mixer drum 10 rotates. To do. That is, one cycle of this capacitance value is T11 to T15. This means that the mixer drum 10 has made one revolution in this one cycle.

  As shown in FIG. 8, the rotation speed when the mixer drum 10 is rotated and the ready-mixed concrete is agitated is measured by using the electrodes 111 that move with the rotation of the mixer drum 10. It is the reciprocal of one period (T11 to T15) of the capacitance value. That is, the rotation speed is obtained by the calculation unit 12 from one cycle (T11 to T15) of the capacitance value, which is a predetermined electrical characteristic measured using each electrode 111.

  The rate of change reached the minimum value Min2 from the time point (T12) when the periodically changing capacitance value measured using the respective electrodes 111 moving with the rotation of the mixer drum 10 started to decrease from the maximum value Max2. This is the time (T12 to T13) until the time (T13). That is, the calculation unit 12 obtains the time (T12 to T13) when the capacitance value measured using each electrode 111 changes from the maximum value Max2 to the minimum value Min2. That is, the change rate of the capacitance value from the state where each electrode 111 is completely buried in the ready-mixed concrete until it is completely exposed to the space above the ready-mixed concrete is measured. Thus, the rotation speed and the change speed can be obtained by the calculation unit 12 from the capacitance value measured using each electrode 111. The slump value can be obtained by the computing unit 12 using the database recorded in the recording unit 13 from the rotation speed and the change speed obtained by the computing unit 12.

  As described above, the mixer vehicle of the second embodiment also has only to measure the change rate of the capacitance value using one type of electrode 111 when obtaining the slump value. Also good. Further, this mixer vehicle obtains the slump value by using the change rate of the capacitance value. Even if this mixer car is hardened with ready mixed concrete adhering to the electrode 111 and has an influence on the absolute value of the measured capacitance value, it hardly affects the rate of change of the capacitance value. . For this reason, this mixer vehicle can obtain the slump value without being affected by the state around the electrode 111.

  Therefore, the mixer truck of the second embodiment can also satisfactorily obtain the slump value of ready-mixed concrete that is stirred by the mixer drum 10.

  In the mixer vehicle of the second embodiment, the calculation unit 12 calculates the capacitance value from the time (T12 to T13) when the capacitance value measured using the electrode 111 changes from the maximum value Max2 to the minimum value Min2. Seeking the rate of change. For this reason, since this mixer vehicle can easily measure the maximum value Max2 and the minimum value Min2 of the capacitance value using the electrode 111, the change rate of the capacitance value can be easily obtained.

  In the mixer vehicle of the second embodiment, the calculation unit 12 obtains the rotational speed of the mixer drum 10 from one cycle (T11 to T15) of the capacitance value measured using the electrode 111. For this reason, since this mixer vehicle can determine the rotation speed of the mixer drum 10 using the electrode 111 for determining the change rate of the capacitance value, it is not necessary to separately provide a tachometer or the like.

  Further, in this mixer vehicle, the recording unit 13 records a database that stores the rotation speed of the mixer drum 10, the change speed of the electrical characteristics, and the slump value obtained from the rotation speed and the change speed. Further, the calculation unit 12 obtains the slump value from the database stored in the recording unit 13. For this reason, this mixer vehicle measures the rotational speed of the mixer drum 10 and the change speed of the electrical characteristics using the electrode 111 and records the values in the recording unit 13 for the rotational speed and electrical characteristics of the mixer drum 10. By making it correspond to the changing speed, the slump value can be easily obtained.

  In addition, this mixer truck measures the change rate of the electrical characteristics from the state in which the electrode 111 is buried in the ready-mixed concrete until it is exposed to the space above the ready-mixed concrete. For this reason, when the mixer drum 10 rotates, the ready-mixed concrete thrown up is lifted along the inner peripheral surface of the mixer drum 10. As a result, the time taken for the electrode 111 rotating with the rotation of the mixer drum 10 to be exposed to the space above the ready-mixed concrete from the ready-mixed concrete is until it is buried in the ready-mixed concrete from the space above the ready-mixed concrete. Longer than the time it takes. That is, since this mixer vehicle can measure the side where the electrical characteristics change longer, the speed of change of the electrical characteristics can be obtained more accurately.

<Other embodiments>
The present invention is not limited to Embodiments 1 and 2 described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the first embodiment, a plurality of slump values corresponding to the rotation speed and the change speed are stored in the database and recorded in the recording unit. However, the load capacity of the ready mixed concrete is set to the rotation speed and the change speed. In addition, slump values corresponding to these three types of values may be stored in a database and recorded in the recording unit. In this case, the load of ready-mixed concrete is obtained based on the ratio of the time for each electrode to move in the space above the ready-mixed concrete and the time for the electrode to move in the ready-mixed concrete. Specifically, if the load capacity of the ready-mixed concrete is different, the overhead wire connecting the rotating shaft from the lower end of the mixer drum when each electrode is completely exposed to the space above the ready-mixed concrete from the ready-mixed concrete and each electrode The angle formed by the overhead line connecting the rotation axes changes. Thereby, even if the slump value of ready mixed concrete does not change, the change rate of a resistance value or an electrostatic capacitance value changes. For this reason, a more accurate slump value can be obtained by using a database to which the load of ready mixed concrete is added.
(2) In Embodiments 1 and 2, the rotation speed is obtained by the calculation unit, but it may not be obtained by the calculation unit, and the rotation speed may be obtained by providing a tachometer or the like.
(3) In Embodiment 1, the time when the resistance value measured using each electrode changes from the minimum value to the maximum value is used as the change speed. Not limited to this, an intermediate time from when the resistance value increases from the minimum value to the maximum value may be used as the change speed.
(4) In Embodiment 2, the time when the capacitance value measured using each electrode changes from the maximum value to the minimum value is used as the change speed. However, the present invention is not limited to this, and an intermediate time from when the capacitance value decreases from the maximum value to the minimum value may be used as the change speed.
(5) In the first embodiment, the time when the resistance value measured using each electrode changes from the minimum value to the maximum value is used as the change speed. Not limited to this, the time when the resistance value measured using each electrode changes from the maximum value to the minimum value may be used as the change speed.
(6) In Embodiment 2, the time when the capacitance value measured using each electrode changes from the maximum value to the minimum value is used as the change rate. Not limited to this, the time when the capacitance value measured using each electrode changes from the minimum value to the maximum value may be used as the change speed.
(7) In the first embodiment, the rotational force obtained from the engine as the power source is transmitted to the mixer drum, but the power source may not be the engine, and the rotational force obtained from the electric motor or the like is used as the power source. It may be used as
(8) In the first embodiment, the mixer vehicle is used. However, the present invention is not limited to this, and a mixer in which a frame is installed at a work site or the like and a mixer drum is rotatably mounted may be used. In this case, the rotational force for rotating the mixer drum may be obtained from an electric motor or the like.

  10G ... Rotating shaft, 10 ... Mixer drum, 11 ... Electrode, 12 ... Calculation unit, 13 ... Recording unit, Min1, Min2 ... (for comparison) minimum value, Max1, Max2 ... (for comparison) maximum value

Claims (5)

A mixer drum having a rotating shaft extending in the lateral direction and into which ready-mixed concrete is charged leaving a space on the upper side;
An electrode that is provided in the mixer drum and moves on a predetermined circumference around the rotation axis of the mixer drum as the mixer drum rotates to measure a predetermined electrical characteristic;
A calculation unit for obtaining a slump value corresponding to a rotation speed of the mixer drum when the ready-mixed concrete is stirred, and a change speed of the electrical characteristics measured using the electrode at that time;
A mixer characterized by comprising.   The calculation unit obtains the change rate of the electrical characteristics from the time when the electrical characteristics measured using the electrodes change from the minimum value to the maximum value, or from the time when the electrical characteristics change from the maximum value to the minimum value. The mixer according to claim 1.   3. The mixer according to claim 1, wherein the calculation unit obtains a rotational speed of the mixer drum from one cycle of the electrical characteristic measured using the electrode.   A recording unit in which a rotation speed of the mixer drum, a change rate of the electrical characteristics, and a database storing the slump value obtained from the rotation rate and the change rate are recorded, and the calculation unit is included in the recording unit 4. The mixer according to claim 1, wherein a slump value is obtained from a stored database.   5. The change rate of the electrical characteristics from when the electrode is buried in the ready-mixed concrete to being exposed to an upper space of the ready-mixed concrete is measured. 6. Mixer.

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