JP2024087955A - PVC irrigation header - Google Patents

Abstract

To provide an irrigation header that can prolong a service life, is easy to replace and maintain, and is inexpensive and durable.SOLUTION: The present invention is a polyvinyl chloride-based irrigation header that branches a water supply destination from a water pipe to a plurality of destinations, the irrigation header comprising: a polyvinyl chloride-based joint member for connecting to the water pipe; a polyvinyl chloride-based main water supply pipe; a polyvinyl chloride-based pipe member arranged between the joint member and the main water supply pipe; a polyvinyl chloride-based end cap provided at a rear end part of the main water supply pipe; and a hose joint nipple or hose joint mounted to a plurality of polyvinyl chloride-based branch pipes provided on the main water supply pipe, where connection parts between the main water supply pipe and the branch pipes are integrated by welding.SELECTED DRAWING: Figure 1

Description

The present invention relates to an irrigation header, and more specifically to technology for an irrigation header in which the connections to the branch pipes, which are provided on a PVC main water supply pipe, are integrated by welding.

For healthy growth of vegetables, it is necessary that various environmental factors surrounding the above-ground and below-ground parts of the plant are in an optimal state for the plant. These include various factors such as light, temperature, humidity, and carbon dioxide concentration, but among these, water, which plants need, plays an important role. Water makes up a large part of the plant body, and within the plant, it serves as the raw material for photosynthesis, aids in the movement of inorganic elements absorbed through the roots and assimilated products synthesized in the leaves, and also regulates the temperature of the leaves by evaporating water from the stomata in the leaves. However, transpiration can cause temporary wilting of the plant body during sunny days, and if the soil dries out and moisture is not replenished, the plant will wilt permanently and die from dehydration. In order to prevent death, it is very important to provide a stable supply of water to the soil.

Water is also necessary for photosynthesis, the process by which plants create their own nutrients. However, only a small portion of the water absorbed by the roots is used in photosynthesis, and more than 200 times the amount of water that is broken down into oxygen during photosynthesis is lost through transpiration. When plants are placed in dry conditions, their stomata close to suppress transpiration, and when the stomata are closed, carbon dioxide cannot be taken in, and the rate of photosynthesis naturally drops. Therefore, water plays a very important role in plants, and appropriate watering is necessary to keep the soil at an appropriate humidity level and ensure stable growth without stressing the plants.

Here, when growing crops in greenhouses or other facilities where rain does not fall, or when growing outdoors and the soil dries out due to a long period of no rain during hot summers, artificial watering of crops is called irrigation. Irrigation is generally done by burying an irrigation hose underground or placing it at the base of the crops on the ground surface to water the farmland. The irrigation hoses used are of various types, ranging from those with holes made with a needle, to those with very small holes made with a laser, to those with holes on one side or those with holes on both sides. The holes are also spaced finely, and the water is distributed along the hose to the soil. There are many types, such as spray types that spray water in a soft mist, drip types that slowly soak water, and multi-type types. Furthermore, the thickness of the hose, i.e. the water pressure it can withstand, varies, so it is necessary to choose one according to the purpose, such as the farmland and the crop. In order to arrange these irrigation hoses in long, thin, straight rows at intervals for each pile of soil, irrigation headers are used to branch the water supplied from the water pipes.

Irrigation hoses become clogged after long-term use and should be replaced periodically, roughly once a year. Therefore, it is desirable for the irrigation header to be easily connected to the irrigation hose, and it is also necessary for it to be strong enough to withstand frequent removal and attachment. For this reason, conventional irrigation headers are made of metal, and the connection between the main water supply pipe and the branch pipe is firmly joined by welding or other methods. In the case of carbon steel or low-alloy steel, which is not stainless steel, welding produces metal structures different from the raw materials, such as solidified structures, quenched structures, normalized structures, and annealed structures, at the welded parts. These structures have slightly different corrosion resistances (corrosion potentials). Since these dissimilar structures are joined at the welded parts, a potential difference occurs between the structures, causing corrosion (dissimilar metal corrosion, galvanic corrosion), and the welded parts are more susceptible to rust than the parent material, which has a uniform structure. There is also a method of applying burring to the relevant joint of the main water supply pipe and screwing in the branch pipe, but this is not ideal because of the cost issues associated with the increased processing load, and the difficulty of adjusting the angle when tightening, which can cause water leakage. In the case of stainless steel, it can be joined by Tig welding, but the problem of high material and processing costs remains. Therefore, in order to solve the problem of whether it is possible to create a low-cost, durable irrigation header without the problems of rust and corrosion, we focused on polyvinyl chloride, which is already used as a material for water pipes, and came up with the idea of using it for irrigation headers, and completed this invention.

Irrigation headers have very different characteristics depending on the material they are made from, so if you consider that, for example, you could choose from metals such as iron, lead, copper, and stainless steel. For example, iron is the most workable metal and has sufficient strength. Iron has the advantage that it does not break easily and there is a low risk of it being damaged in an earthquake, but on the other hand, it has the major disadvantage that it rusts easily, and it is prone to oxidation, so clogging due to rust is a problem for irrigation headers. In this regard, stainless steel has the advantage that iron does not have, being strong and durable, while not rusting. However, there are still issues such as high material and processing costs, and each has its pros and cons.

In response to this, it is possible to use resin (HIVP). Resins generally have characteristics such as watertightness and high corrosion resistance, and PVC and polyethylene pipes, which are already in use as water pipes, are lightweight and highly corrosion resistant. Another major feature is that they are easy to process, and length can be easily adjusted, so production does not require much effort. However, even when simply called resin, there are many different types, each of which has its own disadvantages, so careful consideration is required when selecting a resin material. For example, polyethylene is resistant to heat and vibration and can be used for a variety of purposes, but the drawback is that it can develop holes in sunlight. If a hole develops, it will naturally have to be replaced.

When using irrigation systems for large-scale greenhouse or open-field cultivation, the systems also become quite large-scale, and in recent years, advances in IT technology have led to the construction of systems that allow irrigation times to be set in advance and irrigation to be performed remotely from anywhere using a mobile device such as a smartphone (registered trademark). However, the introduction of such systems requires a large financial burden, and depending on the size of the farm, this can pose a major cost problem.

In addition, it is desirable to have a compact irrigation header that can be easily connected to various irrigation components, such as irrigation hoses that branch off from the irrigation header, in a small space, so that it does not get in the way of installing or taking out a multi-sheet recovery device, for example, in a small greenhouse.

In addition, like other agricultural equipment, irrigation equipment requires maintenance in order to be used over the long term, but the initial investment required for irrigation equipment is relatively high, and it can take several years to recoup the investment if multiple units are installed. For this reason, there is a demand for irrigation headers that can be manufactured and installed at low cost.

In order to meet such demands, various technical proposals have been made in the past. For example, a technology entitled "Piping structure and construction method of the piping structure" has been disclosed (see Patent Document 1). Specifically, the objective of the present invention is to "provide a piping structure and a construction method of the piping structure that can easily construct prefabricated piping with stable quality," and the solution is to "provide a piping structure of prefabricated piping in which a pipe material and a joint are connected in advance and then laid in a target laying area, the piping structure has a sleeve-penetrating pipe material 7 that can penetrate a sleeve formed in the target laying area and is arranged on one side of the sleeve penetration direction, a second prefabricated piping has a connecting pipe material that can be connected to the sleeve-penetrating pipe material and is arranged on the other side of the sleeve penetration direction, and a connecting member that connects the sleeve-penetrating pipe material and the connecting pipe material." However, the invention described in Patent Document 1 has a technical feature in that the joints between the pipes are joined using a sleeve-penetrating pipe, a three-way branch joint, or a fastener clip, and does not ensure strength by welding the connection between the main water supply pipe and the branch pipe as in the present invention.

Also, a technology entitled "Joint and joint with divider, and piping system method and piping construction method using the same" has been disclosed (see Patent Document 2). Specifically, the problem to be solved is described as "A branch pipe used in a prefabricated construction method for building piping, and a piping method using the same, which is easy to position the branch and easy to join, requires a small diameter communication hole in the floor, does not require a large space for construction, and can be constructed without damaging or deforming the piping." The solution is described as "A joint with branch pipe used in a prefabricated construction method for piping. The joint with branch pipe is composed of a joint body having an upper joint and a lower joint, each of which has the same central axis, and a body, a branch part that joins a branch pipe to the body of the joint body, and a main pipe part to which a certain length of main pipe is joined to one of the upper joint and the lower joint, and is characterized in that the other connection part of the connection part to which the main pipe is joined is an electric fusion joint." However, the invention described in Patent Document 2 has in common with the present invention the joining means for the main water supply pipe and the branch pipe in that the joints where the ends of the pipes are inserted and joined are electric fusion joints, but is characterized in that the other joint of the joint joined to the main pipe is an electric fusion joint, and differs from the present invention in that the branch pipe and the main pipe are not integrated.

In addition, a technology entitled "Method and prior art device for drilling plastic pipes" has been disclosed (see Patent Document 3). Specifically, the objective is to "provide a method and device for drilling plastic pipes that suppresses heat generation and softening of the resin during cutting, and is less likely to cause cutting chips to become entangled in the blade of the rotary cutting blade. To provide a method and device for drilling plastic pipes that is less likely to leave cutting chips in the pipeline after cutting." The solution to this objective is to "connect a pipe member for branching a pipeline to the pipe opening at one end of the tubular part of the check valve in a state where it surrounds the intended drilling location in the pipe wall of the plastic pipe. A drilling device main body is attached to the pipe opening at the other end of the tubular part. The rotary cutting blade of the drilling device main body is made capable of moving in and out of the intended drilling location through the pipeline formed by the tubular part and the pipe member. With the check valve kept open, water is supplied to the intended drilling location through the water passage of the pipe member, while the wall of the plastic pipe is drilled with the rotary cutting blade of the drilling device main body. The cutting chips are collected in the body of the rotary drilling blade." However, the invention described in Patent Document 3 aims to provide a method and device for drilling plastic pipes that suppresses heat generation and softening of the resin during cutting, making it less likely that cutting chips will become entangled in the cutting edge of the rotary cutting blade. It can be used as a preliminary step to the means for connecting the main water supply pipe and the branch pipe, but it aims to solve a different problem than the means for fusing the main water supply pipe and the branch pipe of the present invention.

JP 2018-80463 A JP 2006-105389 A JP 2001-82662 A

The objective of the present invention is to provide a low-cost, durable irrigation header that has a long service life and is easy to replace and maintain.

The present invention is an irrigation header made of polyvinyl chloride that branches water supply destinations from a water pipe to multiple destinations, comprising: a polyvinyl chloride joint member for connecting to the water pipe; a polyvinyl chloride main water supply pipe; a polyvinyl chloride piping member arranged between the joint member and the main water supply pipe; a polyvinyl chloride end cap provided at the rear end of the main water supply pipe; and hose joint nipples or hose joints attached to multiple polyvinyl chloride branch pipes provided on the main water supply pipe.
The main water supply pipe and the branch pipe are joined together by welding.

The present invention can also employ a configuration in which an opening and closing cock is provided on the joint member.

The polyvinyl chloride irrigation header of the present invention has the excellent effect of being able to be manufactured at a lower cost than conventional metal irrigation headers.

The polyvinyl chloride irrigation header of the present invention has the excellent effect of preventing rust and corrosion caused by the chlorine contained in tap water.

The polyvinyl chloride irrigation header of the present invention is small, lightweight, and easy to install, and has the excellent effect of being easily installed without taking up space even in small spaces such as greenhouses.

In addition, the polyvinyl chloride irrigation header of the present invention has the excellent effect of eliminating the risk of water leakage and providing high strength, as the main water supply pipe and the branch pipe are integrated using a welding means.

In addition, when the polyvinyl chloride irrigation header of the present invention is configured with an opening and closing cock, it has the excellent effect of being able to open and close the water supply to all branch pipes.

FIG. 2 is an explanatory perspective view of the basic configuration of a polyvinyl chloride irrigation header according to the present invention. FIG. 11 is an explanatory diagram showing the configuration of another embodiment of the polyvinyl chloride irrigation header according to the present invention. FIG. 11 is an explanatory diagram showing another example of the branch pipe arrangement configuration in a polyvinyl chloride irrigation header according to the present invention. FIG. 2 is an explanatory diagram showing the use of a polyvinyl chloride irrigation header according to the present invention.

The present invention is an irrigation header made of polyvinyl chloride that branches water supply destinations from a water pipe to multiple destinations, comprising: a polyvinyl chloride joint member for connecting to the water pipe; a polyvinyl chloride main water supply pipe; a polyvinyl chloride piping member arranged between the joint member and the main water supply pipe; a polyvinyl chloride end cap provided at the rear end of the main water supply pipe; and hose joint nipples or hose joints attached to multiple polyvinyl chloride branch pipes provided on the main water supply pipe.
The main feature of the present invention is that the joint between the main water supply pipe and the branch pipe is integrated by welding. The following description will be given based on the drawings. However, the present invention is not limited to the shapes and configurations shown in the drawings, and may be modified within the scope of the effects of the invention as a creation of the technical concept.

Figure 1 is a diagram illustrating the basic configuration of a polyvinyl chloride irrigation header 1 according to the present invention. In this figure, the main water supply pipe 40 is folded back and arranged parallel to a vertically standing water pipe, and six branch pipes, three each, are arranged in the same direction. Each component will be described below based on this figure.

The water pipe 10 is a water pipe that supplies water W, which is essential for plant growth. Waterworks are also an important water supply facility, and the ministerial ordinance that prescribes the technical standards for waterworks facilities based on the Waterworks Act stipulates that the water pressure at the point where the water distribution pipe branches into the water supply pipe must be in the range of 0.15 MPa to 0.74 MPa. This water pressure is used to irrigate the water from the irrigation header through the irrigation hose 100. In addition, when taking water from the waterworks, in order to ensure a large amount of water, there is a method of storing water in a water storage tank and then sending it with an irrigation pump. Note that in the mornings and evenings, when demand from households is high, the water pressure may temporarily drop, and it may be necessary to deal with this by storing the water in a large water storage tank. If the water pipe is a thick main pipe, there is no problem, but if it is a branch pipe, the water pressure may not be enough, so care must be taken as to where the water is taken from.

The vinyl chloride 20 is the material of the basic components of the vinyl chloride irrigation header 1 according to the present invention. The term "vinyl chloride" is a general term including "vinyl chloride resin" or "polyvinyl chloride", and is also abbreviated as "PVC", a type of plastic made by polymerizing vinyl chloride (chloroethylene). In English, it is written as PVC (Poly Vinyl Chloride). Flexible PVC is also called soft vinyl or soft vinyl.
PVC is classified as one of the five major general-purpose resins, along with polyethylene (PE), polypropylene (PP), and polystyrene (PS), and although its performance is not very high, it is inexpensive and produced in large quantities. Another feature is that hard and soft products can be obtained by adjusting the amount of plasticizer added during the manufacturing process. PVC is made from ethylene and chlorine, which are inexpensive and mass-produced, and has the advantage of being able to be manufactured with less resources than other resin products made from petroleum.

Difference between polyvinyl chloride and vinyl chloride Polyvinyl chloride is a compound made by repeatedly bonding together the monomer vinyl chloride (chloroethylene), and the word "poly" in polyvinyl chloride comes from polymer and means "a lot." However, the commonly used word "vinyl chloride" often refers to polyvinyl chloride, not vinyl chloride. As mentioned above, the "vinyl chloride 20" of this invention includes both polyvinyl chloride (vinyl chloride) and vinyl chloride.

Regarding soft PVC and hard PVC, there are two types of PVC: "soft PVC" and "hard PVC". Soft PVC is a soft material, and even if it is somewhat thick, it is flexible enough to be bent by hand. On the other hand, hard PVC is hard and has excellent strength. The difference between them is not only in hardness, but also in physical properties and mechanical properties. For example, the specific gravity of soft PVC is 1.16 to 1.35, while that of hard PVC is 1.30 to 1.58. There is also a large difference in tensile strength, with soft PVC being 6.9 to 25 MPa and hard PVC being 34 to 62 MPa. Due to the difference in strength, it is desirable to use hard PVC for the polyvinyl chloride 20 according to the present invention.

Regarding the degree of polymerization (molecular weight) of PVC, a polymer is a compound formed by repeatedly bonding together monomers, which are relatively small molecules. The degree of this bonding is called the "degree of polymerization." By changing the degree of polymerization, PVC can be used for a variety of purposes.

Here, the main advantages and disadvantages of PVC 20 will be explained.
Advantages of PVC 20: Chemical resistance: Highly resistant to chemicals.
-Acid and alkali resistance: Resistant to acids and alkalis.
・Water resistance: Water does not pass through.
-Electrical insulation: Does not conduct electricity easily.
- Flame retardancy: With a high oxygen index of 45 to 49, it is classified as a self-extinguishing resin.
-Durability: Little deterioration over time under normal usage conditions.
- Coloring and printing processability: Coloring and pattern printing are possible.
・Low price: It is cheaper than other materials. It is not heavy, so transportation and management costs can be reduced.
Disadvantages of PVC 20 (heat resistance and melting point)
-Heat resistance: PVC has a heat resistance of 60 to 80°C and a melting point of about 85 to 210°C, so it has poor heat resistance.
・Impact resistance: It has poor impact resistance compared to the other five major general-purpose resins. The impact value decreases especially in low temperature environments.

Water W refers to tap water supplied through water pipe 10. Tap water in Japan meets strict hygiene standards and does not contain chemicals that would kill plants, so there is no need to worry about the water quality. Furthermore, the fresh water W supplied from this tap water has the effect of promoting plant growth. Note that this water W is not limited to tap water, but also includes rainwater.

The joint member 30 is a member for connecting and connecting the water pipe 10 and the main water supply pipe 40.

The main water supply pipe 40 is a water pipe that guides the water W supplied from the water pipe 10 to the branch pipe 90.

The piping member 50 is a member used to change the direction of the flow path when the water pipe is configured vertically. In the basic configuration shown in Figure 1, two L-shaped elbows are combined and folded back into a U-shape so that the water pipe 10 and the main water supply pipe 40 are parallel, but in a configuration in which the main water supply pipe 40 is arranged horizontally as shown in Figures 2 and 3, one elbow is sufficient. In addition, although not shown in the drawings, joint fittings and the like are installed inside. In addition, the joints of the piping members 50, which are members made of these polyvinyl chloride 20, can be made by using an adhesive for PVC pipes, and the adhesive is made by dissolving the base material (PVC resin) in an organic solvent, and a special adhesive that complies with the Japan Water Works Association standard JWWA S101 "Adhesive for rigid polyvinyl chloride pipes for water use" is used.

The end cap 60 closes the flow path of the main water supply pipe 40. It is positioned at a distance from the branch pipe 90 to ensure a fixing section for fixing the main water supply pipe 40 to a fixing frame F or the like with metal fittings after passing the branch pipe 90.

The hose joint nipple 70 is a component that connects the hose to the hose joint 71.

The hose joint 71 is a member provided for attaching the hose joint nipple 70 to the branch pipe 90. The hose joint 71 may be configured as a one-touch coupling type or a screw-in joint type.

The joint 80 is the joint between the main water supply pipe 40 and the branch pipe 90, which would have been connected by gluing or screwing in the past. In the irrigation header 1 made of polyvinyl chloride according to the present invention, the main water supply pipe 40 and the branch pipe 90 are integrated by the welding means. For the welding means, a dedicated device for PVC that uses a heat gun and a welding rod for welding is considered. This is adjusted to the optimal temperature and air pressure for PVC welding, and while melting the joint, a welding rod of the same material as the base material is used to add build-up and fuse both together. In conventional metal irrigation headers, when iron is welded to the joint, the oxidation of the welded part causes durability problems, and when the material is changed to a thin-walled stainless steel pipe from the standpoint of weight reduction and maintenance, it becomes difficult to connect the main water supply pipe 40 and the branch pipe 90. Problems arise with thinning in the joining means such as screwing and welding, such as forming the flange part by burring processing or welding stainless steel by TIG welding, which causes differences in the joining strength depending on the skill level of the welder. In addition, there are plastic irrigation headers on the market in which the main water supply pipe 40 and the branch pipes 90 are integrated by injection molding, but this requires high mold costs and does not solve the problem of the present invention, which is to reduce costs.

The branch pipe 90 is a pipe for branching the water W supplied from the main water supply pipe 40. In Figs. 1 to 4, an example in which it is branched into six pipes is shown, but the number is not limited to this and may be selected appropriately in relation to the water pressure and water volume. Furthermore, such branch pipes must be firmly fixed in place, especially since they are pushed in to connect the hose joint 71 and hose joint nipple 70 when they are detached from each other. Furthermore, they must be installed with consideration given to fatigue damage caused by repeated detachment.

The irrigation hose 100 comes in a variety of types, from those with holes made with a needle to those with very small holes made with a laser, to those with holes on one side or those with holes on both sides. The holes are also spaced finely, and there are many different types. Water W is distributed along this irrigation hose 100 to the soil. There are many types, such as a spray type that spreads water W in a soft mist, a drip type that gradually soaks water W, and a multi-type. Furthermore, the thickness of the irrigation hose 100, that is, the water pressure it can withstand, differs for each type, and it is necessary to select one according to the purpose, such as the farmland and crops. The irrigation hose 100 is used to branch the water W supplied from a water pipe and supply water W to plants S, so that it can be placed in each of the ridges of soil that are piled up in long, thin, straight lines at intervals.

Figure 2 is an explanatory diagram showing the configuration of another embodiment of the polyvinyl chloride irrigation header according to the present invention, in which the main water supply pipe 40 is bent 90 degrees horizontally relative to the vertically rising water pipe 10, six branch pipes 90 are arranged downward in groups of three in the same direction, and an opening/closing cock 31 is provided on the joint member 30 for connecting the water pipe 10 and the main water supply pipe 40. Figure 2(a) shows a front view, and Figure 2(b) shows a plan view.

The on-off cock 31 is a so-called main valve that opens and closes the supply of water to the main water supply pipe 40. The cock shown in the drawing is merely an example, and is not limited to this type of cock. It may be replaced with a valve, etc.

Figure 3 is an explanatory diagram showing another branch pipe arrangement configuration example in a polyvinyl chloride irrigation header according to the present invention. Figure 3(a) shows a front view, and Figure 3(b) shows a plan view. Figure 3 shows an example configuration in which six branch pipes 90 are linearly arranged in the same direction in a row along the longitudinal direction of the horizontally arranged main water supply pipe 40. In this arrangement example, all branch pipes 90 are aligned in one direction, resulting in a slimmer design with less depth.

Figure 4 is an explanatory diagram showing the use of the polyvinyl chloride irrigation header 1 according to the present invention. As shown in Figure 4, water W is being irrigated to plants S planted in three ridges by irrigation hoses 100, three of which are distributed to the left and right of the main water supply pipe 40. In this arrangement, the branch pipes 90 are arranged in two directions, so the length of the main water supply pipe 40 can be shortened and made compact.

The polyvinyl chloride irrigation header of the present invention is believed to have high industrial applicability, particularly in the agricultural field, because it can reduce the burden of watering, particularly in greenhouse cultivation of strawberries, and can provide an irrigation header that is low cost and has a long service life.

1 PVC irrigation header 10 Water pipe 20 PVC 30 Joint member 31 Opening/closing cock 40 Main water supply pipe 50 Piping member 60 End cap 70 Hose joint nipple 71 Hose joint 80 Joint 90 Branch pipe 100 Irrigation hose
W Water

Claims (2)

An irrigation header (1) made of polyvinyl chloride (20) that branches water (W) from a water pipe (10) to multiple supply destinations,
The water pipe (10) and a main water supply pipe (40) made of polyvinyl chloride;
A polyvinyl chloride joint member (30) for connecting the water pipe (10) and the main water supply pipe (40);
A piping member (50) made of polyvinyl chloride and arranged between the joint member (30) and the main water supply pipe (40);
An end cap (60) made of vinyl chloride provided at the rear end of the main water supply pipe (40);
A hose joint nipple (70) or a hose joint (71) to be attached to a branch pipe (90) made of vinyl chloride provided in a plurality of the main water supply pipes (40);
It consists of
The irrigation header (1) is made of polyvinyl chloride, characterized in that the connection portion (80) of the main water supply pipe (40) and the branch pipe (90) are integrated by welding. The irrigation header (1) made of polyvinyl chloride is characterized in that the joint member (30) is provided with an opening and closing cock (31).