JP6831741B2 - Emitter and drip irrigation tubes - Google Patents

Description

The present invention relates to an emitter and a drip irrigation tube having the emitter.

The drip irrigation method is known as one of the plant cultivation methods. The drip irrigation method is a method in which a drip irrigation tube is placed on or in the soil where plants are planted, and an irrigation liquid such as water or liquid fertilizer is dropped from the drip irrigation tube to the soil. One of the advantages of the drip irrigation method is that the consumption of irrigation liquid can be minimized.

The drip irrigation tube includes a tube in which a plurality of through holes are formed and a plurality of emitters (also referred to as "drippers") that are joined to the inner wall surface of the tube and for quantitatively discharging irrigation liquid from each through hole. (See, for example, Patent Document 1). The irrigation liquid is pumped into the tube, for example, and discharged out of the tube through the through hole via the emitter.

The emitter described in Patent Document 1 has a first member, a second member, and a film member arranged between the first member and the second member. The first member has an intake for taking in the irrigation liquid into the emitter, and a wall portion arranged inside the first member so as to surround the intake. The second member has an outlet for discharging the irrigation liquid to the outside of the emitter. By stacking the first member, the membrane member, and the second member in this order, a flow path through which the flow irrigation liquid can move is provided between the first member and the membrane member and between the second member and the membrane member. It is formed. The membrane member has a through hole for moving the liquid taken into the emitter from the intake port from the flow path between the first member and the membrane member to the flow path between the second member and the membrane member. Has been done.

Further, in the emitter described in Patent Document 1, the intake port is closed when the membrane member comes into contact with the wall portion. In the emitter, when the pressure of the irrigation liquid in the tube becomes equal to or higher than a predetermined value, the membrane member blocking the intake port is pressed by the irrigation liquid and deformed. The irrigation liquid flows into the emitter through the gap created between the membrane member and the wall portion due to the deformation of the membrane member.

Japanese Unexamined Patent Publication No. 2010-046094

In general, the irrigation liquid in the tube is continuously discharged to the outside of the tube for a certain period of time even after the liquid feeding into the tube is stopped. When the drip irrigation tube is placed in a place with a height difference, the amount of irrigation liquid discharged from the emitter at a lower position is larger than the amount of irrigation liquid discharged from the emitter at a higher position. .. As a result, the pressure in the tube at a high position becomes negative. As a result, a fluid such as air or water containing fine soil may flow back from the outside of the tube into the flow path of the emitter. As described above, the backflow phenomenon of the fluid (hereinafter, also referred to as “siphon phenomenon”) that may occur due to the negative pressure in the tube may contaminate the inside of the emitter or cause clogging.

On the other hand, in the emitter described in Patent Document 1, when the pressure of the irrigation liquid in the tube becomes less than a predetermined value after the liquid feeding is stopped, the intake port is closed by the membrane member. Therefore, the occurrence of the siphon phenomenon can be suppressed. However, in the emitter described in Patent Document 1, if the pressure in the tube is too low, the intake port is blocked by the membrane member, so that there is a problem that the irrigation liquid cannot be properly discharged.

An object of the present invention is to provide an emitter and a drip irrigation tube capable of suppressing the occurrence of the siphon phenomenon and appropriately discharging the irrigation liquid even when the pressure of the irrigation liquid in the tube is low. ..

In order to solve the above problems, the emitter according to the present invention has a first surface and a second surface which are in a front-to-back relationship with each other, and communicates inside and outside the tube on the inner wall surface of the tube through which the irrigation liquid flows. It is an emitter for quantitatively discharging the irrigation liquid in the tube to the outside of the tube from the discharge port, which is joined at a position corresponding to the discharge port, and is arranged on the first surface and the irrigation. A water intake section for taking in the liquid for irrigation, a discharge section arranged on the second surface for discharging the irrigation liquid, the water intake section and the discharge section are connected, and the irrigation liquid is circulated. It has a flow path and a water sealing accommodating portion arranged in the flow path and accommodating the sealing water.

In order to solve the above problems, the drip irrigation tube according to the present invention is joined to a tube having a discharge port for discharging an irrigation liquid at a position corresponding to the discharge port on the inner wall surface of the tube. , The emitter according to the present invention.

According to the emitter and the drip irrigation tube according to the present invention, the occurrence of the siphon phenomenon can be suppressed, and the irrigation liquid can be appropriately discharged even if the pressure of the irrigation liquid in the tube is low.

1A and 1B are cross-sectional views showing an example of the configuration of a drip irrigation tube according to an embodiment. 2A to 2C are diagrams showing the configuration of the emitter or the emitter main body according to the embodiment. FIG. 3 is a diagram showing a configuration of an emitter according to an embodiment. 4A to 4C are schematic cross-sectional views for explaining the operation of the flow rate reducing portion. 5A and 5B are views showing an example of the configuration of the integrally molded cover and film according to the first modification. 6A and 6B are views showing an example of the configuration of the integrally molded cover and film according to the second modification.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[Construction of drip irrigation tube and emitter]
1A and 1B are cross-sectional views showing an example of the configuration of the drip irrigation tube 100 according to the present embodiment. FIG. 1A is a cross-sectional view of the drip irrigation tube 100 in the axial direction, and FIG. 1B is a cross-sectional view of the drip irrigation tube 100 in the direction perpendicular to the axial direction. The drip irrigation tube 100 has a tube 110 and an emitter 120.

The tube 110 is a tube for flowing an irrigation liquid. The irrigation liquid is pumped into the tube 110, for example. A plurality of discharge ports 112 for discharging the irrigation liquid to the outside of the tube 110 are formed on the tube wall of the tube 110 at predetermined intervals (for example, 200 to 500 mm) in the axial direction of the tube 110. The diameter of the opening of the discharge port 112 is not particularly limited as long as the irrigation liquid can pass through. In the present embodiment, the diameter of the opening of the discharge port 112 is 1.5 mm. Emitters 120 are joined to positions of the inner wall surface of the tube 110 corresponding to the discharge port 112. The cross-sectional shape and cross-sectional area perpendicular to the axial direction of the tube 110 are not particularly limited as long as the emitter 120 can be arranged inside the tube 110.

The material of the tube 110 is not particularly limited. In this embodiment, the material of the tube 110 is polyethylene.

Examples of irrigation liquids include water, liquid fertilizers, pesticides and mixtures thereof.

2A to 2C are views showing the configuration of the emitter 120 or the emitter main body 121 according to the present embodiment. 2A is a plan view of the emitter body 121, FIG. 2B is a plan view of the emitter 120, and FIG. 2C is a bottom view of the emitter 120. FIG. 3 is a diagram showing the configuration of the emitter 120 according to the present embodiment. FIG. 3 is a cross-sectional view taken along the line AA shown in FIG. 2B.

As shown in FIG. 1A, the emitter 120 is joined to the inner wall surface of the tube 110 so as to cover the discharge port 112. The shape of the emitter 120 is not particularly limited as long as it can be brought into close contact with the inner wall surface of the tube 110 and cover the discharge port 112. In the present embodiment, the shape of the back surface of the emitter 120 joined to the inner wall surface of the tube 110 in the cross section in the direction perpendicular to the axial direction of the tube 110 is the inner wall surface of the tube 110 so as to follow the inner wall surface of the tube 110. It has a substantially arc shape that is convex toward. The plan-view shape of the emitter 120 is a substantially rectangular shape with four corners chamfered. The size of the emitter 120 is not particularly limited. In the present embodiment, the length of the emitter 120 in the long side direction is 25 mm, the length in the short side direction is 8 mm, and the height is 2.5 mm.

The emitter 120 according to the present embodiment is composed of at least an emitter body 121, a film 122, and a cover 123. Details of the function of the emitter 120 will be described later.

The emitter body 121 (emitter 120) has a first surface 1211 and a second surface 1212 that are in a front-to-back relationship with each other. In the present embodiment, the first surface 1211 is located on the front surface side (irrigation liquid side) of the emitter 120, and the second surface 1212 is located on the back surface side (tube 110 side) of the emitter 120.

Recesses, grooves, protrusions and through holes are appropriately formed in the emitter body 121 within a range in which the effects of the present embodiment can be obtained. Although details will be described later, in the present embodiment, at least a water intake recess 153, a flow rate reduction recess 161 and a backflow prevention recess 171 are formed on the first surface 1211 of the emitter body 121 (FIG. 2A). reference). Further, at least the first connection groove 131, the first decompression groove 132, the second connection groove 133, the second decompression groove 134, and the discharge recess 181 are formed on the second surface 1212 of the emitter body 121 (FIG. See 2C).

The emitter body 121 may be made of a flexible material or a rigid material. Examples of materials for the emitter body 121 include resins and rubber. Examples of such resins include polyethylene and silicone. The flexibility of the emitter body 121 can be adjusted by the use of an elastic resin material. Examples of the method for adjusting the flexibility of the emitter body 121 include selection of an elastic resin, adjustment of a mixing ratio of the elastic resin material with respect to the hard resin material, and the like. The emitter body 121 can be manufactured, for example, by injection molding.

The film 122 is joined to a part of the first surface 1211 of the emitter body 121. The film 122 is arranged on the emitter body 121 so as to close the opening of the flow rate reducing recess 161. That is, the film 122 is bonded to the emitter body 121 at a portion outside the opening. The film 122 is flexible and deforms under the pressure of the irrigation liquid.

The shape and size of the film 122 can be appropriately set according to the shape and size of the emitter body 121, the shape and size of the opening of the flow rate reducing recess 161 formed in the emitter body 121, and the like. The thickness of the film 122 can be appropriately set according to the desired flexibility.

The film 122 is made of a flexible resin material. The material of the film 122 can be appropriately set according to the desired flexibility. Examples of such resins include polyethylene and silicone. The flexibility of film 122 can also be adjusted by the use of elastic resin material. An example of the method of adjusting the flexibility of the film 122 is the same as the method of adjusting the flexibility of the emitter body 121. The film 122 can be manufactured, for example, by injection molding.

The emitter body 121 and the film 122 may be integrated or separate. For example, the emitter body 121 and the film 122 may be integrally formed via a hinge portion, respectively. The film 122 may be rotated around the hinge portion to join the film 122 to the first surface 1211 of the emitter body 121. The method of joining the emitter body 121 and the film 122 is not particularly limited. Examples of the joining method include welding of a resin material, bonding with an adhesive, and the like. The hinge portion may be cut after joining the emitter body 121 and the film 122.

The cover 123 is joined to a part of the first surface 1211 of the main body of the emitter 121. The cover 123 is arranged on the emitter body 121 so as to close the opening of the backflow prevention recess 171. That is, the cover 123 is joined to the emitter body 121 at a portion outside the opening. The shape and size of the cover 123 can be appropriately set according to the shape and size of the emitter body 121, the shape and size of the opening of the backflow prevention recess 171 formed in the emitter body 121, and the like.

A ridge 124 is formed on one surface of the cover 123. The ridge 124 is arranged so as to project toward the backflow prevention recess 171 formed in the emitter body 121. Further, as shown in FIG. 3, the ridge 124 is arranged in the cover 123 at a position corresponding to the dent 172 arranged on the bottom surface of the backflow prevention recess 171. Specifically, the ridge 124 is arranged in the ridge 172 so as to be separated from the inner surface of the ridge 172, and extends along the ridge 172. In other words, the ridge 124 extends along a direction that traverses the flow direction of the irrigation liquid. A gap is formed between the ridge 124 and the dent 172. The gap forms part of the flow path through which the irrigation liquid can move.

Although the details will be described later, a liquid (sealing water) for blocking the flow path in the middle can be accommodated between the ridges 124 and the ridges 172. The position, shape, size and number of the ridges 124 are not particularly limited as long as the sealing water can be accommodated between the ridges 124 and the ridges 172, and are appropriately set according to the shape and size of the ridges 172. Can be done. Examples of the shape of the ridge 124 include a cylindrical shape and a square tubular shape. In the present embodiment, the shape of the ridge 124 is a cylindrical shape. In the present embodiment, the number of ridges 124 is two. The two ridges 124 are arranged concentrically.

The cover 123 may be made of a flexible material or a rigid material. Examples of materials for the cover 123 include resins, rubbers and metals. Examples of such resins include polyethylene and silicone. The flexibility of the cover 123 is the same as the method of adjusting the flexibility of the emitter body 121. The cover 123 can be manufactured, for example, by injection molding. From the viewpoint of suppressing the deformation of the cover 123 due to the pressure of the irrigation liquid and keeping the size of the gap (a part of the flow path) between the ridges 124 and the ridges 172 constant, the cover 123 is , Preferably made of a rigid material. In this embodiment, the cover 123 is made of a rigid material.

In the present specification, the “rigid material” means a material having a rigidity such that the member formed by the material is not deformed by the pressure of the irrigation liquid. For example, when the cover 123 is made of a rigid material, the material means a material having such a rigidity that the distance between the ridges 124 and the ridges 172 is substantially unchanged by the pressure of the irrigation liquid. To do.

The emitter body 121 and the cover 123 may be integrated or separate. The example of the method of joining the emitter body 121 and the cover 123 is the same as the example of the method of joining the emitter body 121 and the film 122.

The film 122 and the cover 123 may be integrated (see Modifications 1 and 2 described later), or may be separate bodies. When the film 122 and the cover 123 are integrated, the film 122 and the cover 123 are both flexible. In this embodiment, the film 122 and the cover 123 are separate bodies. From the viewpoint of imparting rigidity to the cover 123, it is preferable that the film 122 and the cover 123 are separate bodies.

The drip irrigation tube 100 is made by joining the back surface of the emitter 120 to the inner wall surface of the tube 110. The method of joining the tube 110 and the emitter 120 is not particularly limited. Examples of the joining method include welding of resin materials constituting the emitter 120 or the tube 110, bonding with an adhesive, and the like. Normally, the discharge port 112 is formed after joining the tube 110 and the emitter 120, but it may be formed before joining.

The emitter 120 includes a water intake unit 150, a first connection flow path 141, a first decompression flow path 142, a second connection flow path 143, a second decompression flow path 144, a flow rate reduction unit 160, a backflow prevention unit 170, and a discharge unit 180. Have. The water intake unit 150, the flow rate reduction unit 160, and the backflow prevention unit 170 are arranged on the surface of the emitter 120 (first surface 1211 of the emitter body 121). Further, the first connection flow path 141, the first decompression flow path 142, the second connection flow path 143, the second decompression flow path 144, and the discharge portion 180 are located on the back surface of the emitter 120 (the second surface 1212 of the emitter body 121). It is arranged.

By joining the emitter 120 and the tube 110 to each other, the water intake section 150, the first connection flow path 141, the first decompression flow path 142, the second connection flow path 143, the second decompression flow path 144, the flow rate reduction section 160, The backflow prevention portion 170 and the discharge portion 180 are formed. Further, in the emitter 120, a flow path connecting the water intake unit 150 and the discharge unit 180 is also formed. The flow path allows the irrigation liquid to flow from the intake section 150 to the discharge section 180.

The water intake unit 150 takes in the irrigation liquid into the emitter 120. The water intake unit 150 is arranged in a region of about half of the first surface 1211 of the emitter body 121 (see FIGS. 2A and 2B). The water intake unit 150 has a water intake side screen unit 151 and a water intake through hole 152.

The water intake side screen portion 151 prevents suspended matter in the irrigation liquid taken into the emitter 120 from entering the emitter 120. The water intake side screen portion 151 is open to the inside of the tube 110 and has a water intake recess 153, a plurality of slits 154, and a plurality of screen protrusions 155.

The water intake recess 153 is a recess formed in a region where the film 122 is not joined on the first surface 1211 of the emitter body 121. The depth of the water intake recess 153 is not particularly limited, and is appropriately set according to the size of the emitter 120. A plurality of slits 154 are formed on the outer peripheral wall of the water intake recess 153, and a plurality of screen protrusions 155 are formed on the bottom surface of the water intake recess 153. Further, a water intake through hole 152 is formed on the bottom surface of the water intake recess 153.

The plurality of slits 154 connect the inner surface of the water intake recess 153 and the outer surface of the emitter body 121, and while taking in the irrigation liquid from the side surface of the emitter body 121 into the water intake recess 153, the irrigation liquid is contained. Prevents the suspended matter from entering the water intake recess 153. The shape of the slit 154 is not particularly limited as long as it can exhibit the above-mentioned functions. In the present embodiment, the shape of the slit 154 is formed so that the width increases from the outer surface of the emitter body 121 toward the inner surface of the water intake recess 153 (see FIGS. 2A and 2B). As described above, since the slit 154 is configured to have a so-called wedge wire structure, the pressure loss of the irrigation liquid flowing into the water intake recess 153 is suppressed.

The plurality of screen protrusions 155 are arranged on the bottom surface of the water intake recess 153. The arrangement and number of the ridges 155 for the screen are not particularly limited as long as the irrigation liquid can be taken in from the opening side of the intake recess 153 and the intrusion of suspended matter in the irrigation liquid can be prevented. In the present embodiment, the plurality of screen ridges 155 are arranged so that the major axis direction of the screen ridge 155 is along the minor axis direction of the emitter 120. Further, the ridge portion 155 for the screen is formed so that the width decreases from the first surface 1211 of the emitter main body 121 toward the bottom surface of the water intake recess 153. That is, in the arrangement direction of the screen ridges 155, the space between the adjacent screen ridges 155 has a so-called wedge wire structure. Further, the distance between the adjacent projections 155 for the screen is not particularly limited as long as the above-mentioned functions can be exhibited. As described above, since the space between the adjacent screen protrusions 155 is configured to have a so-called wedge wire structure, the pressure loss of the irrigation liquid flowing into the water intake recess 153 is suppressed.

The water intake through hole 152 is formed on the bottom surface of the water intake recess 153. The shape and number of the water intake through holes 152 are not particularly limited as long as the irrigation liquid taken into the water intake recess 153 can be taken into the emitter body 121. In the present embodiment, the water intake through hole 152 is one elongated hole formed along the long axis direction of the emitter 120 on the bottom surface of the water intake recess 153. Since this elongated hole is partially covered by a plurality of screen protrusions 155, the water intake through hole 152 is divided into a large number of through holes when viewed from the first surface 1211 side. appear.

The irrigation liquid that has flowed through the tube 110 is taken into the emitter body 121 while the water intake side screen portion 151 prevents suspended matter from entering the water intake recess 153.

The first connection flow path 141 (first connection groove 131) is arranged in the flow path, and connects the water intake portion 150 (water intake through hole 152) and the first decompression flow path 142 (first decompression groove 132). Connecting. The first connection flow path 141 (first connection groove 131) is linearly arranged along the long axis direction of the emitter 120 at the outer edge of the second surface 1212 of the emitter body 121. By joining the tube 110 and the emitter 120, the first connection flow path 141 is formed by the first connection groove 131 and the inner wall surface of the tube 110. The irrigation liquid taken in from the water intake unit 150 flows to the first decompression flow path 142 through the first connection flow path 141.

The first decompression flow path 142 (first decompression groove 132) is arranged downstream of the first connection flow path 141 in the flow path, and is the first connection flow path 141 (first connection groove 131) and the second connection flow. It connects to the road 143 (second connection groove 133). The first decompression flow path 142 reduces the pressure of the irrigation liquid taken in from the intake unit 150 and leads to the second connection flow path 143. The first decompression flow path 142 (first decompression groove 132) is linearly arranged along the long axis direction of the emitter 120 at the outer edge of the second surface 1212 of the emitter body 121. In the present embodiment, the upstream end of the first decompression flow path 142 is connected to the first connection flow path 141, and the downstream end of the first decompression flow path 142 is connected to the upstream end of the second connection flow path 143. ing.

The shape of the first pressure reducing groove 132 is not particularly limited as long as it can exhibit the above-mentioned functions. In the present embodiment, the plan view shape of the first decompression groove 132 is a zigzag shape. In the first decompression groove 132, first convex portions 1361 having a substantially triangular prism shape protruding from the inner side surface are alternately arranged along the flow direction of the irrigation liquid. The first convex portion 1361 is arranged so that the tip does not exceed the central axis of the first decompression groove 132 when viewed in a plan view. By joining the tube 110 and the emitter 120 to each other, the first decompression flow path 142 is formed by the first decompression groove 132 and the inner wall surface of the tube 110. The irrigation liquid taken in from the water intake unit 150 is decompressed by the first decompression flow path 142 and guided to the second connection flow path 143 (second connection groove 133).

The second connection flow path 143 (second connection groove 133) is arranged downstream of the first decompression flow path 142 in the flow path, and is the first decompression flow path 142 (first decompression groove 132) and the second decompression flow path 142. It is connected to the flow path 144 (second pressure reducing groove 134). The second connection flow path 143 is formed linearly along the minor axis direction of the emitter 120 at the outer edge of the second surface 1212 of the emitter body 121. By joining the tube 110 and the emitter 120, the second connection flow path 143 is formed by the second connection groove 133 and the inner wall surface of the tube 110. The irrigation liquid taken in from the water intake unit 150, guided to the first connecting flow path 141, and decompressed by the first decompression flow path 142 passes through the second connection flow path 143 and is guided to the second decompression flow path 144. Irrigation.

The second decompression flow path 144 (second decompression groove 134) is arranged downstream of the second connection flow path 143 in the flow path, and includes the second connection groove 133 (second connection flow path 143) and the flow rate reducing unit. Connect with 160. The second decompression flow path 144 reduces the pressure of the irrigation liquid flowing in from the second connection flow path 143 and leads it to the flow rate reduction unit 160. The second decompression flow path 144 (second decompression groove 134) is arranged along the major axis direction of the emitter 120 at the outer edge of the second surface 1212 of the emitter body 121. The upstream end of the second decompression groove 134 is connected to the downstream end of the second connection groove 133, and the downstream end of the second decompression flow path 144 is connected to the first connection through hole 164 of the flow rate reducing portion 160. ..

The shape of the second pressure reducing groove 134 is not particularly limited as long as it can exhibit the above-mentioned functions. In the present embodiment, the plan view shape of the second decompression groove 134 is a zigzag shape similar to the shape of the first decompression groove 132. In the second decompression groove 134, second convex portions 1362 having a substantially triangular prism shape protruding from the inner side surface are alternately arranged along the direction in which the irrigation liquid flows. The second convex portion 1362 is arranged so that its tip does not exceed the central axis of the second pressure reducing groove 134 when viewed in a plan view. By joining the tube 110 and the emitter 120, the second decompression flow path 144 is formed by the second decompression groove 134 and the inner wall surface of the tube 110. The irrigation liquid taken in from the water intake unit 150 is decompressed by the first decompression flow path 142 and the second decompression flow path 144, and is guided to the flow rate reduction unit 160.

The flow rate reducing unit 160 is arranged upstream of the backflow prevention unit 170 and downstream of the second decompression flow path 144 in the flow path, and is arranged on the surface side of the emitter 120. The flow rate reducing unit 160 sends the irrigation liquid to the backflow prevention unit 170 while reducing the flow rate of the irrigation liquid according to the deformation of the film 122 due to the pressure of the irrigation liquid in the tube 110.

The configuration of the flow rate reducing unit 160 is not particularly limited as long as the above functions can be exhibited. In the present embodiment, the flow rate reducing portion 160 has a flow rate reducing recess 161, a valve seat portion 162, a communication groove 163, a first connection through hole 164, a second connection through hole 165, and a diaphragm portion 166.

The flow rate reducing recess 161 is arranged on the first surface 1211 of the emitter body 121. The plan view shape of the flow rate reducing recess 161 is not particularly limited, and is, for example, a substantially circular shape. The depth of the flow rate reducing recess 161 is not particularly limited, and may be equal to or greater than the depth of the communication groove 163. A first connection through hole 164 and a second connection through hole 165 are opened on the inner surface of the flow rate reduction recess 161. In the present embodiment, the first connection through hole 164 and the second connection through hole 165 are open to the bottom surface of the flow rate reduction recess 161.

The valve seat portion 162 is arranged on the bottom surface of the flow rate reducing recess 161. In the present embodiment, the valve seat portion 162 is arranged in a non-contact manner facing the diaphragm portion 166 so as to surround the opening of the second connection through hole 165. The valve seat portion 162 is configured so that the diaphragm portion 166 can be brought into close contact with the valve seat portion 162 when the pressure of the irrigation liquid flowing through the tube 110 exceeds a set value. When the diaphragm portion 166 comes into contact with the valve seat portion 162, the flow rate of the irrigation liquid flowing from the flow rate reducing recess 161 into the backflow prevention portion 170 is reduced.

The shape of the valve seat portion 162 is not particularly limited as long as it can exhibit the above-mentioned functions. In the present embodiment, the valve seat portion 162 is a cylindrical convex portion. In the present embodiment, the height of the end surface of the convex portion from the bottom surface of the flow rate reducing recess 161 decreases from the inside to the outside.

The communication groove 163 communicates the inside of the flow rate reducing recess 161 with the second connection through hole 165 surrounded by the valve seat portion 162. The communication groove 163 is arranged on a part of the surface of the valve seat portion 162 to which the diaphragm portion 166 can be brought into close contact.

The first connection through hole 164 communicates with the upstream side of the flow path in the flow rate reducing portion 160. In the present embodiment, the first connection through hole 164 communicates with the second decompression flow path 144 (second decompression groove 134). The first connection through hole 164 is arranged on the inner surface of the flow rate reducing recess 161. The first connection through hole 164 is arranged, for example, on the bottom surface or the side surface of the flow rate reducing recess 161. In the present embodiment, the first connection through hole 164 is arranged on the bottom surface of the flow rate reducing recess 161 in a region where the valve seat portion 162 is not arranged.

The second connection through hole 165 communicates with the downstream side of the flow path in the flow rate reducing portion 160. In the present embodiment, the second connection through hole 165 communicates with the backflow prevention unit 170. The second connection through hole 165 is arranged on the inner surface of the flow rate reducing recess 161. The second connection through hole 165 is arranged, for example, on the bottom surface or the side surface of the flow rate reducing recess 161. In the present embodiment, the second connection through hole 165 is arranged in the central portion of the bottom surface of the flow rate reducing recess 161.

The positions of the first connection through hole 164 and the second connection through hole 165 are not limited to the embodiment of the present embodiment. For example, the second connection through hole 165 may be arranged outside the valve seat portion 162 instead of the first connection through hole 164. Further, instead of the second connection through hole 165, the first connection through hole 164 may be arranged so as to be surrounded by the valve seat portion 162.

The diaphragm portion 166 is a part of the film 122. The diaphragm portion 166 is arranged so as to block the communication between the inside of the flow rate reducing recess 161 and the inside of the tube 110 and to close the opening of the flow rate reducing recess 161. The diaphragm portion 166 is flexible and deforms so as to come into contact with the valve seat portion 162 in response to the pressure of the irrigation liquid in the tube 110. For example, the diaphragm portion 166 is distorted toward the flow rate reducing recess 161 when the pressure of the irrigation liquid flowing in the tube 110 exceeds a set value. Specifically, the diaphragm portion 166 deforms toward the valve seat portion 162 as the pressure of the irrigation liquid increases, and eventually comes into contact with the valve seat portion 162. Even when the diaphragm portion 166 is in close contact with the valve seat portion 162, the diaphragm portion 166 does not block the first connection through hole 164, the second connection through hole 165, and the communication groove 163. The irrigation liquid from the connection through hole 164 can be sent to the backflow prevention unit 170 through the communication groove 163 and the second connection through hole 165.

The backflow prevention unit 170 is arranged in the flow path downstream of the flow rate adjusting unit 160 and upstream of the discharge unit 180, and is arranged on the surface side of the emitter 120. The backflow prevention unit 170 sends the irrigation liquid to the discharge unit 180, and prevents the fluid flowing back from the discharge unit 180 into the flow path when the liquid supply is stopped from flowing upstream of the backflow prevention unit 170.

Backflow prevention from the viewpoint of suppressing the inside of the flow path of the component for adjusting the discharge amount from the emitter 120 from being contaminated or clogged by the fluid flowing back from the discharge unit 180 into the flow path. The portion 170 is preferably arranged on the downstream side of the flow path. That is, the backflow prevention unit 170 is preferably arranged downstream of the component for adjusting the discharge amount from the emitter 120, and more preferably arranged at a position where it directly communicates with the discharge unit 180. In the present embodiment, since the backflow prevention unit 170 is arranged downstream of the flow rate adjusting unit 160, the fluid that has flowed back into the flow path does not flow into the flow rate adjusting unit 160.

The configuration of the backflow prevention unit 170 is not particularly limited as long as it can exhibit the above-mentioned functions. In the present embodiment, the backflow prevention unit 170 includes a backflow prevention recess 171, a recess 172, a third connection through hole 173 (referred to as a "first through hole" in the claims), and a fourth. It has a connection through hole 174 (referred to as a "second through hole" in the claims), a water sealing accommodating portion 175, and a ridge 124.

The backflow prevention recess 171 is arranged on the first surface 1211 of the emitter body 121. The plan view shape of the backflow prevention recess 171 is not particularly limited, and is, for example, a substantially circular shape. The depth of the backflow prevention recess 171 is not particularly limited. A third connection through hole 173, a fourth connection through hole 174, and a recess 172 are opened on the inner surface of the backflow prevention recess 171. In the present embodiment, the third connection through hole 173, the fourth connection through hole 174, and the recess 172 are open to the bottom surface of the backflow prevention recess 171.

The recess 172 opens at the bottom of the flow path and extends along a direction traversing the flow direction of the irrigation liquid. The recess 172 is arranged on the bottom surface of the backflow prevention recess 171 so as to open toward the first surface 1211 of the emitter body 121. That is, the recess 172 has a bottom portion on the second surface 1212 side of the emitter body 121. Further, in the present embodiment, the recess 172 is arranged so as to surround the opening of the fourth connection through hole 174. As described above, the recess 172 is arranged so that the outer surface of the protrusion 124 and the inner surface of the backflow prevention recess 171 are separated from each other. That is, the recess 172 is arranged so as to form a gap between the recess 172 and the convex 124. As a result, the flow rate of the irrigation liquid flowing from the flow rate reducing recess 161 to the discharge unit 180 can be secured.

The position, shape, size and number of the ridges 172 are not particularly limited as long as the sealing water can be accommodated between the ridges 124 and the ridges 172, and are appropriately set according to the shape and size of the ridges 124. Can be done. Examples of the shape of the recess 172 include a cylindrical shape and a square tubular shape. In the present embodiment, the recess 172 is a cylindrical recess. In this embodiment, the number of recesses 172 is two. The two recesses 172 are arranged concentrically.

The third connection through hole 173 communicates with the upstream side of the flow path in the backflow prevention portion 170. In the present embodiment, the third connection through hole 173 communicates with the flow rate reducing portion 160. The third connection through hole 173 is arranged on the inner surface of the backflow prevention recess 171. The third connection through hole 173 is arranged, for example, on the bottom surface or the side surface of the backflow prevention recess 171. In the present embodiment, the third connection through hole 173 is arranged on the bottom surface of the backflow prevention recess 171.

The fourth connection through hole 174 communicates with the downstream side of the flow path in the backflow prevention portion 170. In the present embodiment, the fourth connection through hole 174 communicates with the discharge portion 180. The fourth connection through hole 174 is arranged on the inner surface of the backflow prevention recess 171. The fourth connection through hole 174 is arranged, for example, on the bottom surface or the side surface of the backflow prevention recess 171. In the present embodiment, the fourth connection through hole 174 is arranged in the central portion of the bottom surface of the backflow prevention recess 171.

The positions of the third connection through hole 173 and the fourth connection through hole 174 are not limited to the embodiment of the present embodiment. For example, instead of the fourth connection through hole 174, the third connection through hole 173 may be arranged so as to be surrounded by the recess 172.

The ridge 124 is a part of the cover 123 and is arranged in the ridge 172 so as to be separated from the inner surface of the dent 172. The distance (shortest distance) between the ridges 124 and the ridges 172 may be such that the flow rate of the irrigation liquid to the discharge portion 180 can be secured and a sufficient amount of sealing water can be accommodated. The interval can be appropriately changed depending on the size of the emitter 120, the intended flow rate of the irrigation liquid, and the like.

The sealed water accommodating unit 175 accommodates the sealed water. In the present embodiment, the water sealing accommodating portion 175 is composed of recesses 172 and protrusions 124. As described above, the ridge 124 is arranged in the ridge 172 so as to be separated from the inner surface of the ridge 172. As a result, the liquid (sealing water) is contained between the recesses 172 and the ridges 124 so as to block the flow path in the middle.

The discharge unit 180 discharges the irrigation liquid to the outside of the emitter 120. The discharge portion 180 is arranged on the second surface 1212 side of the emitter main body 121 so as to face the discharge port 112 of the tube 110. The discharge unit 180 sends the irrigation liquid in the emitter 120 to the discharge port 112 of the tube 110. As a result, the discharge unit 180 can discharge the irrigation liquid to the outside of the emitter 120. The configuration of the discharge unit 180 is not particularly limited as long as it can exhibit the above-mentioned functions. In the present embodiment, the discharge unit 180 has a discharge recess 181 and an intrusion prevention unit 182.

The discharge recess 181 is arranged on the second surface 1212 of the emitter body 121. The plan view shape of the discharge recess 181 is substantially rectangular. A fourth connection through hole 174 and an intrusion prevention portion 182 are arranged on the bottom surface of the discharge recess 181.

The intrusion prevention unit 182 prevents the intrusion of foreign matter from the discharge port 112. The intrusion prevention unit 182 is not particularly limited as long as it can exhibit the above-mentioned functions. In the present embodiment, the intrusion prevention portion 182 is four convex portions arranged adjacent to each other. The four protrusions are arranged so as to be located between the fourth connection through hole 174 and the discharge port 112 when the emitter 120 is joined to the tube 110.

[Operation of drip irrigation tube]
Next, the operation of the drip irrigation tube 100 will be described.

First, the irrigation liquid is sent into the tube 110. The pressure of the irrigation liquid sent to the drip irrigation tube 100 is preferably 0.1 MPa or less so that the drip irrigation method can be easily introduced and the tube 110 and the emitter 120 are prevented from being damaged. .. The irrigation liquid in the tube 110 is taken into the emitter 120 from the water intake 150. Specifically, the irrigation liquid in the tube 110 enters the water intake recess 153 through the slit 154 or the gap between the screen protrusions 155 and passes through the water intake through hole 152. At this time, since the water intake unit 150 has the water intake side screen unit 151 (the gap between the slit 154 and the screen ridge portion 155), suspended matter in the irrigation liquid can be removed. Further, since the intake portion 150 is formed with a so-called wedge wire structure, the pressure loss of the irrigation liquid flowing into the intake portion 150 is suppressed.

The irrigation liquid taken in from the water intake unit 150 reaches the first connection flow path 141. The irrigation liquid that has reached the first connection flow path 141 passes through the first decompression flow path 142 and reaches the second connection flow path 143. The irrigation liquid that has reached the second connecting flow path 143 flows into the second decompression flow path 144. The irrigation liquid that has flowed into the second decompression flow path 144 flows into the flow rate reducing portion 160 through the first connection through hole 164. The irrigation liquid that has flowed into the flow rate reducing unit 160 flows into the backflow prevention unit 170 through the second connection through hole 165 and the third connection through hole 173. The irrigation liquid that has flowed into the backflow prevention unit 170 flows into the discharge unit 180 through the fourth connection through hole 174. The irrigation liquid that has flowed into the discharge unit 180 is discharged from the discharge port 112 of the tube 110 to the outside of the tube 110.

(Operation of flow rate reduction part)
Here, the operation of the flow rate reducing unit 160 according to the pressure of the irrigation liquid in the tube 110 will be described. 4A to 4C are schematic cross-sectional views for explaining the operation of the flow rate reducing unit 160. 4A to 4C are partially enlarged cross-sectional views taken along the line AA shown in FIG. 2B. FIG. 4A is a cross-sectional view when the irrigation liquid is not sent to the tube 110, and FIG. 4B is a cross-sectional view when the pressure of the irrigation liquid in the tube 110 is the first pressure. 4C is a cross-sectional view when the pressure of the irrigation liquid in the tube 110 is a second pressure exceeding the first pressure.

In the flow rate reducing portion 160, the flow rate of the irrigation liquid is controlled by deforming the diaphragm portion 166 so as to distort toward the flow rate reducing recess 161 side according to the pressure of the irrigation liquid in the tube 110. In the present embodiment, since the cover 123 is made of a rigid material, it is not deformed by the pressure of the irrigation liquid.

Before the irrigation liquid is sent into the tube 110, the diaphragm portion 166 is not deformed because the pressure of the irrigation liquid is not applied to the film 122 (see FIG. 4A).

When the irrigation liquid begins to flow into the tube 110, the diaphragm portion 166 begins to deform (see FIG. 4B). However, when the diaphragm portion 166 is not in contact with the valve seat portion 162, the irrigation liquid taken in from the intake portion 150 passes through the flow path in the emitter 120 and goes out from the discharge port 112 of the tube 110 to the outside. It is discharged. As described above, at the start of feeding the irrigation liquid into the tube 110 or when the pressure of the irrigation liquid in the tube 110 is lower than the predetermined pressure, the irrigation taken into the emitter 120 from the intake unit 150 The irrigation liquid is discharged to the outside through the flow path.

When the pressure of the irrigation liquid in the tube 110 is further increased, the diaphragm portion 166 is further deformed toward the valve seat portion 162. Normally, as the pressure of the irrigation liquid increases, the amount of the irrigation liquid flowing through the flow path should increase, but in the emitter 120 according to the present embodiment, the first decompression flow path 142 and the second decompression flow path 142 and the second decompression. By reducing the pressure of the irrigation liquid in the flow path 144 and narrowing the distance between the diaphragm portion 166 and the valve seat portion 162, an excessive increase in the amount of the irrigation liquid flowing through the flow path is prevented (Fig.). See 4B). Then, when the pressure of the irrigation liquid in the tube 110 is equal to or higher than a predetermined value (second pressure), the diaphragm portion 166 comes into contact with the valve seat portion 162 (see FIG. 4C). Even in this case, since the diaphragm portion 166 does not block the first connection through hole 164, the second connection through hole 165, and the communication groove 163, the irrigation liquid taken in from the intake portion 150 is the communication groove. It is discharged to the outside from the discharge port 112 of the tube 110 through 163. As described above, when the pressure of the irrigation liquid in the tube 110 is equal to or higher than the second pressure, the flow rate reducing portion 160 causes the diaphragm portion 166 to come into contact with the valve seat portion 162 to bring the irrigation liquid flowing through the flow path. Suppresses the increase in liquid volume.

In this way, the flow rate reducing unit 160 adjusts the flow rate of the irrigation liquid discharged from the discharge port 112 of the tube 110 according to the deformation of the film 122 due to the pressure of the irrigation liquid in the tube 110. Therefore, the drip irrigation tube 100 according to the present embodiment can discharge a certain amount of the irrigation liquid to the outside of the tube 110 regardless of whether the pressure of the irrigation liquid is low pressure or high pressure.

(Function of backflow prevention part)
Here, the function of the backflow prevention unit 170 will be described. First, for comparison, a comparative emitter having no backflow prevention unit 170 will be described. As described above, when the drip irrigation tube is placed in a place where there is a difference in elevation, when the delivery of the irrigation liquid into the tube 110 is stopped, the irrigation liquid discharged from the emitter at a high position There is a difference between the amount and the amount of irrigation liquid discharged from the emitter at a lower position. As a result, the inside of the tube 110 becomes negative pressure due to the height difference, and as a result, in the drip irrigation tube having the emitter for comparison, a fluid such as air or water containing fine soil is released from the outside of the tube. , A so-called siphon phenomenon may occur in which a backflow flows into the flow path of the emitter.

On the other hand, the emitter 120 according to the present embodiment has a backflow prevention unit 170 including a water sealing unit 175. When the feeding of the irrigation liquid into the tube 110 is stopped, the irrigation liquid is stored as the sealing water in the sealing water accommodating portion 175. As a result, in the emitter 120, the flow path on the upstream side of the sealing water accommodating portion 175 and the flow path on the downstream side of the sealing water accommodating portion 175 are blocked by the sealing water. As a result, it is possible to prevent fluids such as air and water, which are present outside the tube 110 and include fine soil, from flowing upstream of the sealing water accommodating portion 175.

(effect)
As described above, the emitter 120 according to the present embodiment has a water sealing accommodating portion 175 for accommodating the sealing water. As a result, the emitter 120 can suppress the occurrence of the siphon phenomenon and can appropriately discharge the irrigation liquid even if the pressure of the irrigation liquid in the tube 110 is low. Therefore, according to the drip irrigation tube 100 having the emitter 120 according to the present embodiment, it is possible to suppress the occurrence of clogging of the flow path due to the siphon phenomenon even in a place having a height difference, and the inside of the tube. Even when the pressure of the irrigation liquid is low, the irrigation liquid can be discharged quantitatively.

[Modification example]
In the above embodiment, the aspect in which the film 122 and the cover 123 are separate bodies has been described, but in the present invention, the film and the cover may be integrated.

5A and 5B are views showing an example of the configuration of the integrally molded product 125a of the cover and the film according to the first modification. FIG. 5A is a bottom view of the integrally molded product 125a according to the first modification, and FIG. 5B is a cross-sectional view taken along the line BB of FIG. 5A. 6A and 6B are views showing an example of the configuration of the integrally molded product 125b of the cover and the film according to the second modification. FIG. 6A is a bottom view of the integrally molded product 125b according to the modified example 2, and FIG. 6B is a cross-sectional view taken along the line BB of FIG. 6A.

As shown in FIGS. 5A, B and 6A, B, the integrally molded articles 125a, 125b have ridges 124 and diaphragms 166 arranged adjacent to each other. Further, the size and the external visual shape of the integrally molded products 125a and 125b can be appropriately changed according to the size of the emitter body 121. The externally visible shape of the integrally molded product 125a may be rectangular, and the externally visible shape of the integrally molded product 125b may be oval.

Further, in the above embodiment, the mode in which the shapes of the ridges 124 and the ridges 172 constituting the water sealing storage portion 175 are cylindrical, respectively, has been described, but the ridges 124 and the ridges 172 according to the present invention have been described. The shape may be a rectangular parallelepiped shape. In this case, the recess 172 is not arranged so as to surround the opening of the fourth connection through hole 174, but is arranged so that both ends of the recess 172 are connected to the side wall surface of the backflow prevention recess 171. ing. For example, when the backflow prevention recess 171 is viewed in a plan view, the recess 172 has an opening of a third connection through hole 173 and a fourth connection through hole that are open to the bottom surface of the backflow prevention recess 171. It is arranged along a direction orthogonal to the virtual line segment connecting the opening of 174.

Further, the configuration of the emitter and the drip irrigation tube according to the present invention is not limited to the emitter 120 and the drip irrigation tube 100 according to the above embodiment. For example, the emitter is a first decompression flow path 142 and a second decompression channel 142. It is not necessary to have the flow path 144 and the flow rate adjusting unit 160. In this case, the emitter is composed of at least an emitter body and a cover.

Further, in the above embodiment, the emitter 120 and the tube 110 are joined to form the first connection flow path 141, the first decompression flow path 142, the second connection flow path 143, and the second decompression flow path 144. However, even if the first connection flow path 141, the first decompression flow path 142, the second connection flow path 143, and the second decompression flow path 144 are previously formed as flow paths in the emitter 120, Good.

According to the emitter according to the present invention, it is possible to suppress the occurrence of clogging due to the backflow of the fluid outside the tube into the flow path even in a place having a height difference. Therefore, further development of drip irrigation is expected.

100 Drip irrigation tube 110 Tube 112 Discharge port 120 Emitter 121 Emitter body 1211 1st surface 1212 2nd surface 122 Film 123 Cover 124 Convex 125a, 125b Integral molding 131 1st connection groove 132 1st decompression groove 133 2nd connection Groove 134 2nd decompression groove 1361 1st convex part 1362 2nd convex part 141 1st connection flow path 142 1st decompression flow path 143 2nd connection flow path 144 2nd decompression flow path 150 Water intake part 151 Water intake side screen part 152 Water intake Through hole 153 Water intake recess 154 Slit 155 Screen ridge 160 Flow reduction 161 Flow reduction recess 162 Valve seat 163 Communication groove 164 First connection through hole 165 Second connection through hole 166 Diaphragm part 170 Backflow Prevention part 171 Backflow prevention recess 172 Concave 173 Third connection through hole 174 Fourth connection through hole 175 Water seal storage part 180 Discharge part 181 Discharge recess 182 Intrusion prevention part

Claims (9)

It has a first surface and a second surface that are in a front-to-back relationship with each other, and is joined at a position corresponding to a discharge port that communicates inside and outside the tube on the inner wall surface of the tube through which the irrigation liquid flows. An emitter for quantitatively discharging the irrigation liquid from the discharge port to the outside of the tube.
An intake unit arranged on the first surface and for taking in the irrigation liquid,
A discharge unit arranged on the second surface and for discharging the irrigation liquid,
A flow path for connecting the water intake part and the discharge part and allowing the irrigation liquid to flow,
A water-sealing accommodating portion for accommodating water-sealing, which is arranged in the flow path,
Has an emitter. The water sealing housing is
A recess that opens at the bottom of the flow path and extends along a direction that traverses the flow direction of the irrigation liquid.
A ridge that is arranged in the dent so as to be separated from the inner surface of the dent and extends along the dent.
The emitter according to claim 1. The emitter is composed of at least an emitter body having the first surface and the second surface, and a cover joined to the first surface and having the ridges.
The emitter is
A backflow prevention recess, which is arranged on the first surface and whose opening is closed by the cover,
A first through hole that opens on the inner surface of the backflow prevention recess and communicates with the upstream side of the flow path.
A second through hole that opens in the inner surface of the backflow prevention recess and communicates with the discharge portion.
Have more
The recess is arranged on the bottom surface of the backflow prevention recess.
The ridges are arranged on the cover so as to project toward the backflow prevention concave portion side.
The emitter according to claim 2. The emitter according to claim 3, wherein the recess is arranged so as to surround an opening of either the first through hole and the second through hole. The emitter is composed of at least the emitter body, the cover, and a flexible resin film bonded to the first surface.
The emitter is arranged upstream of the water sealing portion in the flow path to reduce the flow rate of the irrigation liquid in response to deformation of the film due to the pressure of the irrigation liquid in the tube. Further has a flow rate reduction part of
The emitter according to claim 3 or 4. The emitter according to claim 5, wherein the cover and the film are separate bodies. The emitter according to any one of claims 3 to 6, wherein the cover is made of a rigid material. The emitter according to claim 5, wherein the cover and the film are integrated. A tube with a discharge port for discharging irrigation liquid,
The emitter according to any one of claims 1 to 8, which is joined to a position corresponding to the discharge port on the inner wall surface of the tube.
Have a drip irrigation tube.

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