JPH0724015Y2 - Flow detector for liquid fertilizer in fertilizer applicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a fluid fertilizer flow detection device in a fertilizer applicator that continuously fertilizes fertilizer in a field.

(Prior Art) Generally, in a fertilizer applicator that continuously feeds a paste or liquid fertilizer by pressure, in order to confirm whether or not fertilization work is being performed smoothly, always check the fertilizer flow state. Need to be For this reason, conventionally, a diaphragm-type pressure detection device was installed in the fertilizer pumping flow path, and when the fertilizer was clogged, the diaphragm bulged due to an increase in fertilizer pressure and the detection switch was turned on, or the diaphragm changed. There is one that attempts to detect the flow state of fertilizer as an analog quantity using a potentiometer or the like. It is also known that a diaphragm detector for high pressure and a diaphragm detector for low pressure are provided in two stages, and the diaphragm for high pressure detects clogging of fertilizer and the diaphragm for low pressure detects the flow state of fertilizer.

(Problems to be solved by the present invention) However, in the case where a single pressure detection device is provided and the detection switch is turned “ON”, the state in which the fertilizer is clogged can be detected, but is the fertilizer flowing? , Or there is a problem that it is not possible to identify whether fertilizer is not flowing at all. Further, in the case of detecting the amount of change of the diaphragm as an analog amount, since the flow velocity and the pressure of the fertilizer are relatively small, there is a drawback that the pressure cannot be accurately detected due to variations in the flexibility of the material of the diaphragm. Even if two high-pressure and low-pressure detectors are installed, the flow of fertilizer is detected by the amount of change in the low-pressure diaphragm, so there is a problem that the detection level will change due to variations in the diaphragm. However, the fact is that the flow condition of the liquid fertilizer cannot be detected accurately.

The present invention has been made in view of the above circumstances in order to solve these problems, and is to detect the fertilizer pressure by providing a pressure detection unit in the pressure-feeding flow path of the liquid fertilizer. A liquid fertilizer for fertilizer application that can detect not only the state of clogging of fertilizer but also whether the fertilizer is being pumped or not flowing at all, and can perform fertilizer operation smoothly. An object of the present invention is to provide a flow detection device.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the technical means taken by the present invention is to provide a venturi-shaped reducing portion in the pumping flow path of the liquid fertilizer to provide a high pressure portion and a low pressure portion of the fertilizer pressure. And a pressure detecting portion having the same or substantially the same pressure receiving detection force as the high pressure portion and the low pressure portion, respectively, and comparing the pressure changes detected by the pressure detecting portions with each other. The pressure change compared by the comparison device detects the clogging state of fertilizer that detects high pressure, the state of no fertilizer that detects no pressure, and the flow state of fertilizer that detects different pressures. It is characterized by being configured to do so.

Therefore, according to the present invention, the liquid fertilizer pumped is
The fertilizer is applied to the field through the pressure feed passage of the fertilizer applicator. At this time, a high-pressure part and a low-pressure part of fertilizer pressure are formed by the flow of fertilizer in the pressure-feeding flow path provided with the venturi-shaped reduction part. The pressure detectors provided in the high pressure portion and the low pressure portion respectively detect the fertilizer pressure, but since both pressure detectors have the same or substantially the same pressure receiving detection force, when the fertilizer is flowing smoothly, The pressure detecting portion provided in the above section operates obviously larger than the pressure detecting section provided in the low pressure portion. Further, when fertilizer does not flow through the pressure-feeding channel due to lack of fertilizer or the like, the fertilizer pressure becomes 0 and none of the pressure detection units operate.
On the other hand, when the liquid fertilizer is clogged, the fertilizer pressure in the pressure-feeding channel rises abnormally, and the pressure detecting portions of the high pressure portion and the low pressure portion both largely operate. Therefore, the flow state of the fertilizer can be reliably detected by relatively comparing the pressure changes detected by both the pressure detection units with the comparison device.

(Embodiment) Next, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Reference numeral 1 is a body of the flow detection device, and a pressure-feeding flow path 2 through which a paste-like or liquid fluid fertilizer is pressure-fed is formed inside the body. An input side hose 3 communicating with the fertilizer tank via a pressure feed pump is provided on the upper side of the pressure feed passage 2.
The output side hose 4 communicating with the fertilizer injection nozzle is connected to the lower side, and a fertilizer applicator for continuously applying the pressure-fed paste-like or liquid fertilizer into the soil of the field is constructed. ing.

The pressure-feeding flow path 2 is provided with a Venturi-shaped reducing portion 5 whose inner diameter is reduced to a small diameter so that the fertilizer can be fed to the input-side hose 3
A high-pressure portion 6 in which the fertilizer pressure becomes high when pumped from and a low-pressure portion 7 in which the fertilizer pressure becomes low due to the Venturi action are formed.

On the upper surface side of the body 1, a communication hole 8 penetrating the body 1 and communicating with the high-pressure portion 6 of the pressure-feeding flow path 2 and the pressure-feeding flow path 2 are provided.
A communication hole 9 communicating with the low pressure part 7 is opened. Both communication holes 8 and 9 are cylindrical flow paths having an inner diameter large enough to allow the paste fertilizer to freely flow.

Reference numeral 10 denotes a pressure detecting portion which is provided so as to face the upper surface of the communication hole 8. A diaphragm 11 made of an elastic material such as rubber is arranged so as to cover the upper surface of the communication hole 8 and is vertically slidable supported by the case 12. A pressure receiving plate 14 that contacts the diaphragm 11 is attached to the lower end of a movable guide 13, and a switch 15 is disposed on the upper end of the guide 13. Further, the guide 13 is constantly urged toward the diaphragm 11 via a spring 16 provided in the case 12. When the fertilizer pressure in the communication hole 8 rises, the diaphragm as shown in FIG.
The guide 13 bulges out, and the guide 13 sliding upward turns the switch 15 to "ON".

Further, the pressure detecting portion 17 is provided on the upper surface of the communication hole 9 communicating with the low pressure portion 7 as in the case of the communication hole 8. Ie
Reference numeral 18 is a diaphragm, 19 is a case, 20 is a guide, 21 is a pressure receiving plate, 22 is a switch, and 23 is a spring, and both the pressure detecting portions 10 and 17 have the same or substantially the same pressure detecting force. ing.

And the high-pressure part 6 and the low-pressure part 7 are formed by the fluidized fertilizer that has been pumped.
The pressure detectors 10 and 17 detect the changes in pressure that occur in the switch and switches 15 and 22, respectively, according to the fertilizer state.
FF ”, which is compared with a comparison device consisting of a microcomputer installed in the machine to detect the fertilizer flow state.

As shown in FIG. 4, it is a matter of course that, as shown in FIG. 4, a part of the pressure-feeding channel 2 may have a large diameter to form a venturi-shaped high-pressure portion 24 and a low-pressure portion 25.

In the configuration as described above, the liquid fertilizer pumped from the input side hose 3 flows through the pumping flow passage 2 and is applied to the field through the output side hose 4. When the fertilizer is flowing smoothly, the fertilizer pressure in the high pressure section 6 becomes higher than that in the low pressure section 7,
Since the pressure detection powers of the pressure detection units 10 and 17 are the same or substantially the same, the pressure detection unit 10 provided in the high pressure unit 6 operates more reliably than the pressure detection unit 17 of the low pressure unit 7, and the switch 15 Only "ON".

Further, when the fertilizer does not flow into the pressure-feeding channel 2 due to lack of fertilizer in the fertilizer tank, the fertilizer pressure in the pressure-feeding channel 2 is 0.
The switches 15 and 22 of the adjacent pressure detectors 10 and 17 are both set to "OF
F ”. On the other hand, if the fertilizer is clogged for some reason, the fertilizer pressure in the pumping flow path 2 becomes abnormally high, so that the pressure detection units 10 and 17 are activated to activate the switch 1
5,22 are both "ON". Therefore, both pressure detectors 1
By comparing the pressure changes detected by 0 and 17 relatively with the comparison device, it can be surely detected whether the fertilizer smoothly flows and is applied, whether it is not flowing at all, or whether the fertilizer is clogged. it can.

Since the pressure changes detected by the two pressure detectors 10 and 17 are compared with each other, the influence of the variation of the diaphragm is less than that of the conventional one that detects the fertilizer state by the change of the operation amount of the diaphragm. It is not received, and the detection level does not change and a detection error does not occur. Moreover, the pressure detecting portions 10 and 17 having the same or substantially the same pressure receiving detection force can use the components of the conventional diaphragm type detection device as they are, and can reduce the production cost.

(Effects of the Invention) In short, the present invention provides a high-pressure part and a low-pressure part of the fertilizer pressure by providing a venturi-shaped reduction part in the pumping flow path of the liquid fertilizer, and in the high-pressure part and the low-pressure part, A pressure detection unit having the same or substantially the same pressure receiving detection force is provided, and a comparison device that relatively compares the pressure changes detected by both pressure detection units is provided. Also the state of clogging of fertilizer that detects high pressure,
In both cases, it was configured to detect the state of no fertilizer that does not detect pressure and the state of fertilizer flow that detects different pressures. Since the pressure change in the state where the fertilizer is present is detected, it is not possible to detect the state where the fertilizer is clogged, and it is possible to reliably detect whether the fertilizer is flowing smoothly or not flowing at all. Moreover, since the high-pressure part and the low-pressure part of the fertilizer pressure are formed in advance by providing the venturi-shaped reduction part in the pressure-feeding flow path of the liquid fertilizer, the detection level does not change due to the variation of the pressure detection part, Moreover, since the comparison device relatively compares the pressure changes detected by the two pressure detection units, a detection error does not occur unlike the conventional case. Moreover, since the pressure detecting portions provided in the high pressure portion and the low pressure portion and having the same or substantially the same pressure detection force can use the components of the conventional diaphragm detecting device as they are, it is possible to reduce the production cost. It is a thing.

[Brief description of drawings]

The drawings show an embodiment of a flow detecting device for fluid fertilizer in a fertilizer applicator according to the present invention. Fig. 1 is a front view of a main part, and Fig. 2 is a partially enlarged view showing an operating state. FIG. 3 is a table of operating states of the switch, and FIG. 4 is a front view of a main part showing another embodiment. In the figure, 2 ... pumping flow path, 5 ... reduction section, 6 ... high pressure section,
7 ... Low pressure part, 10,17 ... Pressure detection part.

Claims (1)

[Scope of utility model registration request] 1. A high-pressure portion and a low-pressure portion of fertilizer pressure are formed by providing a venturi-shaped reduction portion in a pressure-feeding flow path of a liquid fertilizer, and the high pressure portion and the low pressure portion receive the same or substantially the same pressure. A pressure detector having a detection force is provided, and a comparison device for relatively comparing the pressure changes detected by both pressure detectors is provided, and the pressure changes compared by the comparison device are both fertilizers that detect high pressure. A flowable fertilizer flow detection device for a fertilizer applicator, which is configured to detect a clogging state, a fertilizer-free state in which neither pressure is detected, and a fertilizer flow state in which different pressures are detected.