Grain transport mechanism

Abstract

To provide a grain conveying mechanism that uses a common drive motor to operate both a rotary valve and a discharge belt conveyor. [Solution] A grain conveying mechanism comprising: an unloading belt conveyor 5 that transports grain from silo 1 on a conveyor belt 15; a grain discharge device 3 that discharges the grain from silo 1 to the unloading belt conveyor 5 by the drive of a rotary valve 12; and a drive transmission device that transmits the rotation of a drive motor 16 connected to the drive roller 13 to the rotary valve 12, with a belt 26 stretched over pulleys 23 and 25 provided on the rotating shaft 24 of the rotary valve 12 in the grain discharge device 3.

Description

Technical Field

[0001] The present invention relates to a grain conveying mechanism that discharges grains from a silo to a belt conveyor for unloading by means of a rotary valve and conveys them downstream.

Background Art

[0002] In a country elevator, the grains carried in are stored in a silo, discharged from the silo according to the shipping timing, conveyed by a belt conveyor, and transported to a working machine such as a sorting machine located downstream thereof. In the country elevator disclosed in Patent Document 1 below, grains are discharged from a rotary valve provided at the bottom of the silo and are configured to be carried by a belt conveyor for unloading located below it. And, a vibrating sorting machine or the like, which is a working machine, is provided on the downstream side of the belt conveyor for unloading.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a country elevator, a grain conveying mechanism that conveys grains discharged from a silo downstream by a belt conveyor for unloading has problems in terms of installation man-hours and cost because it is necessary to control each drive motor provided in the rotary valve and the belt conveyor for unloading.

[0005] Therefore, an object of the present invention is to provide a grain conveying mechanism having a drive transmission device capable of simultaneously driving a rotary valve and a belt conveyor for unloading with one drive motor.

Means for Solving the Problems

[0006] The grain conveying mechanism according to the present invention comprises: an unloading belt conveyor that transports grain from a silo on a conveyor belt; a grain discharge device that discharges the grain from the silo to the unloading belt conveyor by driving a rotary valve; and a drive transmission device on which a belt is passed over pulleys provided on the rotating shaft of a drive roller that rotates the conveyor belt of the unloading belt conveyor and on the rotating shaft of the rotary valve in the grain discharge device, and which transmits the rotation of a drive motor connected to the rotating shaft of the drive roller to the rotary valve. [Effects of the Invention]

[0007] According to the above configuration, the rotational output of the drive motor provides rotation to the conveyor belt of the discharge belt conveyor, and the drive transmission device, which has a belt attached to the pulley of the rotating shaft of the drive motor, also provides rotation to the rotary valve of the grain discharge device. [Brief explanation of the drawing]

[0008] [Figure 1] This is a simplified diagram illustrating one embodiment of a grain conveying mechanism. [Figure 2] This is a conceptual diagram illustrating a method for measuring the flow rate of grain transport. [Figure 3] This is a simplified diagram illustrating a grain transport mechanism for silos arranged side-by-side. [Modes for carrying out the invention]

[0009] An embodiment of the grain conveying mechanism according to the present invention will be described below with reference to the drawings. The grain conveying mechanism of this embodiment is configured at the point where grain is conveyed from the silo of a country elevator to the discharge belt conveyor. In a country elevator, the grain that is brought in is stored in a silo in a dry state, and when it is time for shipment, it is taken out of the silo and conveyed downstream by the discharge belt conveyor. In the case of rice, it is stored in the silo in the form of paddy rice, and the paddy rice taken out of the silo is turned into brown rice by passing it through a hulling machine downstream, and then undergoes sorting by passing it through a grain sorting machine.

[0010] Rice hulling machines and other work machines have an appropriate amount of grain that corresponds to the processing capacity of the machine when performing rice hulling operations. Therefore, it is desirable that the amount of grain flowing on the discharge belt conveyor is such an appropriate amount. The grain conveying mechanism of this embodiment is also suitable for adjusting such conveying flow rates. Figure 1 is a simplified diagram showing one embodiment of the grain conveying mechanism. First, the silo 1 of the country elevator has a cylindrical bottom with an inverted cone-shaped lower end, and an outlet 101 for discharging grain is formed therein. A sliding shutter 2 is provided in the outlet 101, and the stored grain is discharged according to the degree of opening by opening and closing the shutter.

[0011] Below the silo 1, a grain discharge device 3 is provided to receive grain falling from its discharge port 101 and discharge a fixed amount of grain. Furthermore, a transport belt conveyor 5 is positioned below the grain discharge device 3. The grain discharge device 3 incorporates a rotary valve 12 into a funnel-shaped discharge receiving cover 11. The rotary valve 12 has a rotor 21 with multiple blades arranged radially, which is rotatably mounted inside a cylindrical body formed at the bottom of the discharge receiving cover 11. The rotary valve 12 places the grain placed inside the discharge receiving cover 11 into multiple pockets formed by the multiple blades, and discharges a fixed amount from top to bottom as it rotates.

[0012] The conveyor belt 5 for receiving grain falling from the grain discharge device 3 has a conveyor belt 15 stretched over rollers 13 and 14 provided at the beginning and end. The roller 13 at the beginning is a driven roller with the output shaft of a drive motor 16 connected to its rotation axis, and the roller 14 at the end is a driven roller that imparts rotation to the conveyor belt 15. The conveyor belt 15 is stretched vertically over a pair of rollers 13 and 14 that are spaced apart in the grain transport direction (approximately horizontal) and have their rotation axes oriented horizontally (perpendicular to the transport direction). The upper part is the carrier section 151 for loading grain, and the lower part, which is reversed by the roller 14 at the end, is the return section 152.

[0013] Thus, the grain transport mechanism installed downstream of silo 1 has a drive transmission system in which the rotary valve 12 of the grain discharge device 3 does not have its own drive motor, but instead shares the drive motor 16 of the discharge belt conveyor 5. Specifically, a first pulley 23 is fixed to the rotation shaft 22 of the roller 13 of the discharge belt conveyor 5, and a second pulley 25 is fixed to the rotation shaft 24 of the rotor 21 on the rotary valve 12 side. A timing belt 26 is then stretched between the first pulley 23 and the second pulley 25.

[0014] Therefore, in the grain conveying mechanism, when rotation is output from the drive motor 16, the rotation is transferred to the conveyor belt 15 via the roller 13, and at the same time, it is transmitted from the first pulley 23 to the second pulley 25 via the timing belt 26, and rotation is also transferred to the rotor 21 of the rotary valve 12. The grain discharged from the silo 5 and sent into the discharge receiving cover 11 of the grain discharge device 3 moves within the pockets created by the blades of the rotor 21, and is discharged downwards by being dropped from the discharge port according to the rotation speed.

[0015] The grain discharged from the grain discharge device 3 is continuously fed onto the rotating conveyor belt 15 and transported downstream at a constant flow rate. In the grain transport mechanism, the relationship between the transport speed of the discharge belt conveyor 5 and the discharge rate due to the rotational drive of the rotary valve 12 is set based on the gear ratio of the first pulley 23 and the second pulley 25. Therefore, the grain transport flow rate is adjusted according to the rotational control of the drive motor 16.

[0016] For example, an operator monitors the work equipment, such as the aforementioned rice hulling machine, and adjusts the rotation speed of the drive motor 16 to achieve a transport flow rate appropriate for the processing status. However, this method of operator judgment requires the operator to be present at the site at all times for verification. Therefore, next, we will describe a grain transport mechanism that enables control of the drive motor 16 by automatically measuring the transport flow rate of grain flowing on the discharge belt conveyor 5.

[0017] Figure 2 is a conceptual diagram showing a method for measuring the conveying flow rate of grain, and shows a cross-section perpendicular to the conveying direction of the discharge belt conveyor 5. The discharge belt conveyor 5 has multiple intermediate rollers provided at predetermined intervals in the conveying direction between the rollers 13 and 14 at both ends, and the conveying belt 15 is supported by these intermediate rollers. Among these intermediate rollers, the carrier roller 27 that supports the carrier portion 151 of the conveying belt 15 is configured with two rollers on the left and right so that the carrier portion 151, when viewed in the direction of travel, is concave. On the other hand, the return portion 152 of the conveying belt 15 is configured with a single return roller 28 so that it is flat when viewed in the direction of travel.

[0018] The carrier portion 151 has a V-shape with both ends in the width direction being raised and the central portion being lowered. This is to enable the grains 10 discharged from the grain discharging device 3 to flow in a generally constant deposited state. That is, in the present embodiment, a method of measuring the conveyance flow rate of the grains 10 based on the angle of repose θa of the grains 10 mounted on the conveyance belt 15 is adopted. Therefore, when mounting the grains 10 on the conveyance belt 15, it is necessary to create a deposited state in which the angle of repose θa occurs within a range of a predetermined width dimension without the grains 10 spreading in the width direction. Thus, the conveyance belt 15 is configured in a shape that prevents the mounted grains 10 from spreading in the width direction so that the grains 10 are in a deposited state with a certain height.

[0019] The conveyance belt 15 may have a structure that enables the grains 10 to be in a stable deposited state, and it may be different from the V-shape with the deepest valley portion at the center in the width direction as shown in FIG. 2. For example, three carrier rollers may be provided, with the central carrier roller being horizontal and the left and right carrier rollers being vertical, such that both sides in the width direction of the carrier portion 151 are high and the central portion forms a side groove shape with a bottom of a certain width.

[0020] When the granular grains 10 are discharged from the grain discharging device 3 onto the conveyance belt 15 by natural fall, they flow from the central portion to both the left and right sides when viewed in the width direction, and form a deposited state with a substantially symmetric inclined surface as shown in FIG. 2. When a predetermined amount or more of the grains 10 accumulates, the granular grains 10 flow symmetrically to the left and right, and the maximum angle of the inclined surface becomes the angle of repose θa. Although the angle of repose θa varies depending on the type of the grains 10, for the same type of grains 10, it becomes a substantially constant value even if the deposited amount (the height of the deposited grains 10) is different.

[0021] Therefore, a conveying flow rate control system is constructed in the grain conveying mechanism to calculate the conveying flow rate of the grain 10 by using its angle of repose θa and control it so that the amount becomes appropriate. In the conveying flow rate control system, a measuring device 7 for measuring the height of the grain 10 conveyed by the conveying belt 15 is provided above the conveying belt 15 and midway to the roller 14 on the terminal side. In particular, the measuring device 7 is arranged at a position where the deposited state of the grain 10 discharged from the grain discharging device 3 is stable and the angle of repose θa at the top is substantially constant. In this embodiment, a laser rangefinder or the like is used for the measuring device 7.

[0022] The measuring device 7 is connected to a control device 8 that controls the drive motor 16 of the grain conveying mechanism. Further, a rotation meter 17 such as an encoder is provided on the drive motor 16, and this rotation meter 17 is also connected to the control device 8. Therefore, during the conveyance of the grain 10 by the carry-out belt conveyor 5, the detection values by the measuring device 7 and the rotation meter 17 are respectively transmitted to the control device 8.

[0023] The measuring device 7 is installed at a height of the distance A from the bottommost part of the carrier portion 151. Therefore, in the conveying flow rate control system, for the grain 10 being conveyed and deposited on the conveying belt 15 by the detection of the measuring device 7, the distance B to the top is measured in real time, and based on that distance B, the height C of the grain 10 conveyed by the carry-out belt conveyor 5 is obtained. Also, since the angle of repose θa is input in advance for various grains 10 to the control device 8, the cross-sectional area D is calculated from the value of the angle of repose θa and the value of the height C obtained from the measurement result. The cross-sectional area D is obtained by D = C^2 / (tanθa + tanθb), which is inversely proportional to the sum of the tangent functions of the angle of repose θa and the angle θb of the carrier portion 151 of the conveying belt 15 with respect to the squared value of the height C. In the conveying flow rate control system of this embodiment, a data table of the cross-sectional area D calculated based on the above formula for various grains 10 is created and stored in the control device 8.

[0024] The grain 10 transported by the discharge belt conveyor 5 does not have a constant height C, and some irregularities occur. Therefore, if the cross-sectional area D is calculated according to the change in height C, the calculation processing of the transport flow rate E becomes burdensome. In this embodiment, the average value of the height C of the grain 10 detected per unit time is calculated, and the volume (or value converted to mass) obtained by multiplying the cross-sectional area D corresponding to that height C by the distance traveled per unit time is calculated as the transport flow rate E. By adding the transport flow rate E for a predetermined time, it becomes possible to determine the total amount of grain 10 discharged from the silo 5 for shipment, or the amount shipped within a certain time period.

[0025] Furthermore, regarding the unevenness in the height C of the grain 10 flowing on the conveyor belt 6, a moving average may be used to calculate the average of the most recent set of measurements. For example, if the flow rate is displayed numerically on the screen in real time, it becomes difficult to grasp the current value and the trend of increase or decrease if the value of height C fluctuates wildly. Even in such cases, using a moving average makes it easier to grasp the trend of increase or decrease in the height (flow rate) of the grain 10. Note that the value of the moving average differs depending on the number of elements averaged and the measurement period, so the appropriate number of elements should be determined based on the type of grain 10 and various other conditions.

[0026] The grain conveying mechanism of this embodiment can reduce costs because it is configured to drive both the rotary valve 12 and the discharge belt conveyor 5 with a single drive motor 16. Furthermore, since there is a constant relationship between the conveying speed of the discharge belt conveyor 5 and the discharge rate of the rotary valve 12, the conveying flow rate corresponding to the rotation speed of the drive motor 16 can be determined in advance. Therefore, if the actual conveying flow rate E of the grain 10 being conveyed deviates from the conveying flow rate corresponding to the rotation speed of the drive motor 16, the rotation speed of the drive motor 16 will be adjusted and controlled so that the conveying flow rate E becomes the appropriate flow rate. The difference between the rotation speed of the drive motor 16 and the set conveying flow rate can then be corrected according to the calculated conveying flow rate E value.

[0027] Incidentally, in a country elevator, multiple silos are arranged side by side, and a predetermined amount of grain is fed into each silo from a loading belt conveyor. The grain transport mechanism shown in Figure 1 is adapted to the multiple silos 1 by the configuration shown in Figure 3. Figure 3 is a simplified diagram showing the grain transport mechanism corresponding to the side-by-side silos 1. The grain discharge device 3 can be positioned at the point where the grain falls into each of the side-by-side silos 1, and it is necessary that the rotation output from the drive motor 16 is transmitted to the rotary valve 12.

[0028] Therefore, beneath the multiple silos 1 arranged side by side (above the conveyor belt 5 for unloading), a foundation structure, for example, with a horizontal beam structure is constructed, and as shown in Figure 3, one grain discharge device 3 is assembled to move sequentially to the adjacent silo 1. Then, in order to transmit the rotation of the drive motor 16 to the grain discharge device 3 that has been rearranged, a rotation transmission section using pulleys and a timing belt is constructed in the foundation (not shown).

[0029] Specifically, at the position of the second pulley 25 shown in Figure 1, an intermediate pulley 29, with two pulleys mounted on the same axis, is pivotally supported on a base (not shown). The first timing belt 26 is stretched between the first pulley 23 of the discharge belt conveyor 5 and one of the intermediate pulleys 29, and the second timing belt 30 is stretched between the other intermediate pulley 29 and the second pulley 25 of the rotary valve 12. Furthermore, when the grain discharge device 3 moves away from the position shown in Figure 3, the second timing belt 30 is replaced with one that is longer, and an auxiliary pulley is provided between the intermediate pulley 29 and the second pulley 25 as needed.

[0030] Although one embodiment of the present invention has been described above, the present invention is not limited thereto, and various modifications are possible without departing from its spirit. For example, in the above embodiment, an example was described in which the grain discharge device 3 is configured separately from the silo 1. However, by incorporating a rotary valve 12 into the discharge port 101, the grain discharge device 3 may be configured to be part of the silo 1. [Explanation of Symbols]

[0031] 1...Silo 3...Grain discharge device 5...Conveyor belt for unloading 7...Measuring device 8...Control device 10...Grain 12...Rotary valve 15...Conveyor belt 16...Drive motor 23...First pulley 25...Second pulley 26...Timing belt

Claims

1. A conveyor belt for transporting grain from silos on a conveyor belt, A grain discharge device that discharges grain from a silo to the aforementioned discharge belt conveyor by driving a rotary valve, A drive transmission device is provided which a belt is passed over pulleys on the rotating shaft of the drive roller that rotates the conveyor belt of the discharge belt conveyor and the rotating shaft of the rotary valve in the grain discharge device, and which transmits the rotation of a drive motor connected to the rotating shaft of the drive roller to the rotary valve. A grain conveying mechanism having the following features.

2. The grain conveying mechanism according to claim 1, wherein the grain discharge device has a rotary valve incorporated into a funnel-shaped discharge receiving cover that receives grain falling from the discharge port of the silo.

3. A measuring device for measuring the conveying flow rate of grains conveyed by the conveyor belt, A control device that controls the drive of the aforementioned drive motor and calculates the grain transport flow rate based on the measured value of the measuring device, A grain conveying mechanism according to claim 1 or claim 2, having the following features.

4. The grain conveying mechanism according to claim 3, wherein the measuring device is installed above the discharge belt conveyor, measures the distance to the top of the grain piled up and flowing on the discharge belt conveyor, and the control device calculates the cross-sectional area of ​​the grain piled up on the discharge belt conveyor at the measurement position and the volume of grain to be conveyed in a predetermined time based on the cross-sectional area, based on the angle of repose pre-input for the grain and the measured distance obtained by the measuring device.

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