JP2018161113A - Method of manufacturing emitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an emitter which has a plurality of ridges constituting a wedge wire structure, the method making it possible to manufacture the plurality of ridges without forcibly pulling out the ridges.SOLUTION: The present invention relates to a method of manufacturing an emitter which comprises a water intake part for taking in an irrigation liquid, a discharge part dischargeable of the irrigation liquid, and a flow path connecting the water intake part and the discharge part and circulating the irrigation liquid, the water intake part including a screen portion with a wedge wire structure having a plurality of ridges arranged therein. The manufacturing method comprises: fabricating an intermediate molded body of the emitter, the intermediate molded body having a plurality of temporary ridges higher than the ridges in the respective positions where the ridges are disposed, respectively; and forming the plurality of ridges by plastic deformation of the plurality of temporary ridges.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a method for manufacturing an emitter.

  For some time, drip irrigation has been known as one of the methods for growing plants. The drip irrigation method is a method in which a drip irrigation tube is arranged on the soil in which plants are planted, and irrigation liquid such as water or liquid fertilizer is dropped from the drip irrigation tube to the soil. In recent years, drip irrigation has attracted particular attention because it can minimize the consumption of irrigation liquid.

  A drip irrigation tube usually has a tube formed with a plurality of through holes through which irrigation liquid is discharged, and a plurality of emitters (also referred to as “drippers”) for discharging the irrigation liquid from each through hole. . As types of emitters, there are known an emitter that is used while being joined to the inner wall surface of the tube (see, for example, Patent Document 1), and an emitter that is used by piercing the tube from the outside.

  Patent Document 1 describes an emitter joined to the inner wall surface of a tube. The emitter described in Patent Document 1 includes a water intake portion for taking in irrigation liquid, a discharge portion for discharging irrigation liquid, which faces the discharge port penetrating the tube, and the water intake portion and discharge And a flow path through which the irrigation liquid is distributed. Moreover, the emitter described in Patent Document 1 is a screen portion having a wedge wire structure in which a plurality of ridges are arranged in a water intake portion. The screen part which has the said wedge wire structure can prevent that a suspended | floating matter penetrate | invades in a flow path, and can suppress the pressure loss of the water which entered between the protruding ridges.

  Further, Patent Document 1 describes that the emitter can be manufactured by injection molding or the like.

JP 2006-154525 A

  The plurality of ridges constituting the wedge wire structure as the emitter described in Patent Document 1 has an undercut at the time of molding.

  Usually, the undercut is released from the mold by sliding the mold inward or outward. However, since the plurality of ridges are arranged adjacent to each other at a narrow interval in the concave portion constituting the water intake portion, a space for sliding the mold cannot be secured, and the normal undercut is performed. The treatment cannot be released from the mold.

  Therefore, the plurality of ridges are released from the mold by so-called unreasonable pulling out the mold in the height direction of the ridge while deforming the molded body (emitter). Since the emitter as described in Patent Document 1 is made of a flexible material, it can be released without force, and easily returns to its original shape even after force removal. However, even when an emitter is manufactured using such a material, deformation or breakage of the ridge when forcibly removed can occur.

  Therefore, an object of the present invention is to provide a method of manufacturing an emitter having a plurality of ridges constituting a wedge wire structure, and capable of manufacturing the plurality of ridges without forcibly removing them. .

  In order to solve the above-described problems, an emitter manufacturing method according to the present invention is an inner wall surface of a tube through which an irrigation liquid is circulated, and is joined to a position corresponding to a discharge port communicating between the inside and the outside of the tube, An emitter manufacturing method for quantitatively discharging the irrigation liquid in a tube from the discharge port to the outside of the tube. The emitter is provided on the first surface side of an emitter body having a first surface and a second surface that are in a reverse relation to each other, and a water intake portion for taking in the irrigation liquid, and the emitter body A irrigation unit, which is provided on the second surface side, connects the discharge unit that can discharge the irrigation liquid to the outside of the tube when arranged facing the discharge port, and the water intake unit and the discharge unit. And a flow channel through which the liquid for use flows, and the water intake portion has a plurality of ridges arranged on the first surface side so as to be wider than the second surface side. Have The manufacturing method produces an intermediate molded body of the emitter having a plurality of temporary ridges having a height higher than the ridges of the emitter at respective positions where the ridges of the water intake portion are arranged. And a step of plastically deforming the plurality of provisional ridges to form the plurality of ridges.

  The emitter manufacturing method according to the present invention can manufacture an emitter having a plurality of ridges constituting a wedge wire structure without forcibly removing the plurality of ridges.

1A and 1B are cross-sectional views of a drip irrigation tube having an emitter manufactured according to the present invention. 2A and 2B are diagrams showing the configuration of an emitter manufactured according to the present invention. 3A to 3C are diagrams showing the configuration of an emitter manufactured according to the present invention. 4A and 4B are diagrams showing the configuration of an emitter manufactured according to the present invention. FIG. 5 is an enlarged cross-sectional view of the circular portion D shown in FIG. 3C. FIG. 6 is a schematic diagram for explaining a method for manufacturing an emitter according to an embodiment of the present invention. FIG. 7 is an enlarged schematic view for explaining a method for manufacturing an emitter according to an embodiment of the present invention. FIG. 8 is an enlarged schematic view for explaining a method for manufacturing an emitter according to another embodiment of the present invention.

  Hereinafter, an example of an emitter manufactured according to the present invention and a drip irrigation tube in which the emitter is arranged will be described, and then a method for manufacturing the emitter will be described.

(Example configuration of emitter and drip irrigation tubes)
1A is a cross-sectional view in a direction along the axis of a drip irrigation tube 100 having an emitter 120 manufactured according to the present invention, and FIG. 1B is a cross-sectional view in a direction perpendicular to the axis of the drip irrigation tube 100. .

  As shown in FIG. 1, the drip irrigation tube 100 includes a tube 110 and an emitter 120.

  The tube 110 is a tube for flowing an irrigation liquid. The material of the tube 110 is not specifically limited, For example, it can be set as polyethylene. A plurality of discharge ports 112 for discharging irrigation liquid at predetermined intervals (for example, 200 to 500 mm) in the axial direction of the tube 110 are formed on the tube wall 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 be discharged, and can be 1.5 mm, for example. Emitters 120 are respectively joined to positions corresponding to the discharge ports 112 on the inner wall surface of the tube 110. 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 disposed inside the tube 110.

  The drip irrigation tube 100 is manufactured by joining the emitter 120 to the inner wall surface of the tube 110. The method for joining the tube 110 and the emitter 120 is not particularly limited. Examples of the method for joining the tube 110 and the emitter 120 include welding of a resin material constituting the emitter 120 or the tube 110, adhesion by an adhesive, and the like. In addition, although the discharge port 112 is normally formed after joining the tube 110 and the emitter 120, it may be formed before joining.

  FIG. 2A is a plan view of the emitter 120 before joining the emitter body 122 and the film 124, and FIG. 2B is a bottom view of the emitter 120 before joining the emitter body 122 and the film 124. 3A is a front view of the emitter 120 before joining the emitter body 122 and the film 124, FIG. 3B is a cross-sectional view taken along line AA shown in FIG. 2A, and FIG. 3C is a cross-sectional view of FIG. It is sectional drawing of the BB line shown. 4A is a side view of the emitter 120 before joining the emitter body 122 and the film 124, and FIG. 4B is a cross-sectional view of the emitter body 122 taken along line CC shown in FIG. 2A. FIG. 5 is an enlarged cross-sectional view of the circular portion D shown in FIG. 3C.

  As shown in FIGS. 1 to 4, 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 adhere to the inner wall surface of the tube 110 and cover the discharge port 112. In the present embodiment, the shape of the second surface 120b joined to the inner wall surface of the tube 110 in the cross section of the emitter 120 perpendicular to the axial direction of the tube 110 is such that the inner surface of the tube 110 is aligned with the inner wall surface of the tube 110. It has a substantially arc shape that is convex toward the wall surface. The planar shape of the emitter 120 is a substantially rectangular shape with four corners rounded. The size of the emitter 120 is not particularly limited. For example, the length of the emitter 120 in the long side direction can be 25 mm, the length in the short side direction can be 8 mm, and the height can be 2.5 mm.

  The emitter 120 has a first surface 120 a and a second surface 120 b that are in reverse relation to each other, and the second surface 120 b is joined to the inner wall surface of the tube 110, and the emitter body 122 is joined to the emitter body 122. And a film 124. The emitter body 122 and the film 124 are integrally formed via a hinge portion 126 (see FIGS. 2A and 2B).

  Both the emitter body 122 and the film 124 are formed of one kind of flexible material. Examples of the material of the emitter body 122 and the film 124 include resin and rubber. Examples of the resin include polyethylene and silicone. The flexibility of the emitter body 122 and the film 124 can be adjusted by using a resin material having elasticity. Examples of methods for adjusting the flexibility of the emitter body 122 and the film 124 include selection of a resin having elasticity, adjustment of a mixing ratio of a resin material having elasticity to a hard resin material, and the like.

  The emitter body 122 includes a water intake 131, a first connection groove 132 that becomes the first connection flow path 141, a first pressure reduction groove 133 that becomes the first pressure reduction flow path 142, and a second pressure that becomes the second pressure reduction flow path 144. The decompression groove 134, the second connection groove 135 serving as the second connection flow path 145, the flow rate reduction unit 136, the flow path opening / closing unit 137, and the discharge unit 138 are provided. The water intake part 131, the flow rate reduction part 136, and the flow path opening / closing part 137 are disposed on the first surface 120 a side of the emitter body 122. In addition, the first connection groove 132, the first pressure reduction groove 133, the second pressure reduction groove 134, the discharge part 138, and the second connection groove 135 are disposed on the second surface 120 b side of the emitter body 122.

  The film 124 and the emitter body 122 are joined together, and the emitter body 122 and the tube 110 are joined together, whereby the first connection groove 132, the first decompression groove 133, the second decompression groove 134, and the second connection groove 135 are joined. Are a first connection channel 141, a first decompression channel 142, a second decompression channel 144, and a second connection channel 145, respectively. In other words, the first intake passage 131, the first connection passage 141, the first decompression passage 142, the flow rate reduction portion 136, and the discharge portion 138 are formed, and the first passage 143 that connects the intake portion 131 and the discharge portion 138 is formed. The Further, the intake section 131, the first connection flow path 141, the second decompression flow path 144, the flow path opening / closing section 137, the second connection flow path 145, the flow rate reduction section 136, and the discharge section 138 are configured. A second flow path 146 that connects the portion 138 is formed. In each of the first flow path 143 and the second flow path 146, the irrigation liquid is circulated from the water intake section 131 to the discharge section 138. In addition, the emitter body 122 is connected to the flow rate reducing unit 136 downstream of the channel opening / closing unit 137 of the second channel 146, and between the flow rate reducing unit 136 and the discharge unit 138 is connected to the first channel 143 and the first channel 143. The two flow paths 146 overlap.

  The water intake unit 131 is disposed in a region on the first surface 120a side of the emitter body 122 (see FIG. 2A). In the region of the first surface 120a where the water intake portion 131 is not disposed, a flow rate reducing portion 136 and a flow path opening / closing portion 137 (film 124) are disposed. The water intake portion 131 includes a screen portion 151 and a plurality of water intake through holes 152.

  The screen portion 151 prevents floating substances in the irrigation liquid introduced into the emitter body 122 from the first surface 120a side from entering the water intake recess 153. The screen portion 151 is open to the inside of the tube 110 and has a water intake recess 153 and a ridge 154.

  The water intake recess 153 is one recess formed in the entire region where the film 124 is not bonded on the first surface 120 a of the emitter body 122. The depth of the water intake recess 153 is not particularly limited, and is appropriately set depending on the size of the emitter body 122. On the bottom surface of the water intake recess 153, a protrusion 154 is formed. In addition, a water intake through hole 152 is formed on the bottom surface of the water intake recess 153.

  The ridge 154 is disposed on the bottom surface of the water intake recess 153. The arrangement and number of the ridges 154 are not particularly limited as long as the irrigation liquid can be taken in from the opening side of the water intake recess 153 and the intrusion of suspended matter in the irrigation liquid can be prevented. The ridges 154 are arranged along the minor axis direction of the emitter body 122 and a plurality of first ridges 155 arranged in the major axis direction of the emitter body 122, and 1 arranged along the major axis direction of the emitter body 122. Two second ridges 156.

  The first ridges 155 are formed to be wider on the first surface 120a side than on the second surface 120b side (see FIG. 5). That is, the first ridge 155 is formed on the first surface 120a side when the width in the major axis direction of the emitter body 122 is measured at any two points whose positions are different in the height direction (the thickness direction of the emitter body 122). The point has two points that are wider than the point on the second surface 120b side. In addition, it is preferable that the 1st protruding item | line 155 is the widest in the top part. Moreover, the distance between the adjacent 1st protruding item | lines 155 will not be specifically limited if the above-mentioned function can be exhibited. Thereby, in the arrangement direction of the first ridges 155, a space is created between the adjacent first ridges 155 on the bottom surface side of the recess 153 for water intake, and the plurality of first ridges 155 have a so-called wedge wire structure. Configure. Therefore, the 1st protruding item | line 155 can suppress the pressure loss of the water which flowed in into the recessed part 153 for water intake.

  Similarly to the first ridge 155, the second ridge 156 may be formed so that the width increases from the bottom surface side of the water intake recess 153 toward the first surface 120a side of the emitter body 122. Further, it may be formed to have the same width from the bottom surface of the water intake recess 153 to the first surface 120 a of the emitter body 122.

  The water intake through hole 152 is formed on the bottom surface of the water intake recess 153. The shape, position, 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 122. The water intake through hole 152 is a single long hole formed along the long axis direction of the bottom surface of the water intake recess 153. The long hole is covered with a plurality of first ridges 155. Therefore, when viewed from the front side, the water intake through hole 152 appears to be divided into a large number of through holes.

  The first connection groove 132 (first connection flow path 141) connects the water intake through hole 152 (water intake portion 131), the first pressure reduction groove 133, and the second pressure reduction groove 134. The first connection groove 132 is formed in a substantially U shape along the outer edge on the second surface 120 b side of the emitter body 122. A first decompression groove 133 is connected to one end of the first connection groove 132 (the side where the water intake through hole 152 is not disposed), and the second decompression groove is located near the center of the first connection groove 132. 134 is connected. The first connection groove 132 has a zigzag plan view similar to a first decompression groove 133 and a second decompression groove 134, which will be described later, in a part of the region, and is also formed to function as a decompression groove. . By joining the tube 110 and the emitter main body 122 (emitter 120), the first connection channel 141 is formed by the first connection groove 132 and the inner wall surface of the tube 110. The irrigation liquid taken in from the water intake 131 flows through the first connection channel 141 to the first decompression channel 142 and the second decompression channel 144.

  The first pressure reducing groove 133 (first pressure reducing flow path 142) is disposed in the first flow path 143 upstream of the flow rate reducing unit 136, and the flow rate decreases with the first connection groove 132 (first connection flow path 141). The unit 136 is connected. The first depressurization groove 133 (first depressurization flow path 142) reduces the pressure of the irrigation liquid taken from the water intake unit 131 and guides it to the flow rate reduction unit 136. The first decompression groove 133 is disposed along the major axis direction at the outer edge portion on the second surface 120b side. The upstream end of the first pressure reducing groove 133 is connected to the first connecting groove 132, and the flow rate reducing through-hole 161 communicating with the flow rate reducing unit 136 is disposed at the downstream end. The shape of the first decompression groove 133 is not particularly limited as long as the above-described function can be exhibited. In the present embodiment, the plan view shape of the first decompression groove 133 is a zigzag shape. In the first decompression grooves 133, convex portions 162 having a substantially triangular prism shape protruding from the inner surface are alternately arranged along the direction in which the irrigation liquid flows. The convex portion 162 is arranged so that the tip does not exceed the central axis of the first decompression groove 133 when viewed in plan. By joining the tube 110 and the emitter body 122 (emitter 120), the first decompression channel 142 is formed by the first decompression groove 133 and the inner wall surface of the tube 110. Of the irrigation liquid taken in from the water intake unit 131, at least a part of the irrigation liquid is decompressed by the first decompression flow path 142 and guided to the flow rate reduction unit 136.

  The second depressurization groove 134 (second depressurization flow path 144) is disposed in the second flow path 146 upstream of the flow path opening / closing part 137, and flows with the first connection groove 132 (first connection flow path 141). The road opening / closing part 137 is connected. The second decompression groove 134 (second decompression channel 144) guides the irrigation liquid taken from the water intake unit 131 to the channel opening / closing unit 137. The upstream end of the second decompression groove 134 is connected to the connection groove 132, and a flow passage opening / closing through hole 163 communicating with the flow passage opening / closing portion 137 is formed at the downstream end. The second decompression groove 134 has a zigzag planar view similar to the first decompression groove 133 in a part of the region, and is formed so as to function as a decompression groove. By joining the tube 110 and the emitter main body 122 (emitter 120), the second decompression channel 144 is formed by the second decompression groove 134 and a part of the inner wall surface of the tube 110. Among the irrigation liquid taken in from the water intake unit 131, a part of the irrigation liquid passes through the second decompression channel 144 and is guided to the channel opening / closing unit 137.

  The flow rate reduction unit 136 is disposed in the first channel 143 between the first decompression channel 142 (first decompression groove 133) and the discharge unit 138, and on the first surface 120a side of the emitter body 122. Has been placed. The flow rate reduction unit 136 sends the irrigation liquid to the discharge unit 138 while reducing the flow rate of the irrigation liquid according to the pressure of the irrigation liquid in the tube 110. The configuration of the flow rate reduction unit 136 is not particularly limited as long as the above-described function can be exhibited. The flow rate reducing portion 136 includes a flow rate reducing through hole 161 communicated with the first pressure reducing groove 133 (first pressure reducing flow path 142), a flow rate reducing recess portion 171, a first valve seat portion 172, a communication groove 173, A discharge through-hole 174 communicating with the discharge unit 138, a first diaphragm 175 that is a part of the film 124, a first connection hole 176 communicating with the second connection groove 135 (second connection channel 145), Have

  The plan view shape of the flow rate reducing recess 171 is substantially circular. On the bottom surface of the flow rate reducing recess 171, a flow rate reducing through hole 161, a discharge through hole 174, a first connection hole 176, and a first valve seat portion 172 are arranged. The depth of the flow rate reducing recess 171 is not particularly limited as long as it is equal to or greater than the depth of the communication groove 173.

  The discharge through-hole 174 is disposed at the center of the bottom surface of the flow rate reducing recess 171 and communicates with the discharge portion 138.

  The first valve seat 172 is disposed on the bottom surface of the flow rate reducing recess 171 so as to surround the discharge through-hole 174. The first valve seat portion 172 is formed so that the first diaphragm portion 175 can be in close contact when the pressure of the irrigation liquid flowing through the tube 110 is high. When the first diaphragm portion 175 comes into contact with the first valve seat portion 172, the flow rate of the irrigation liquid flowing from the flow rate reducing recess portion 171 into the discharge portion 138 is reduced. The shape of the 1st valve seat part 172 will not be specifically limited if the above-mentioned function can be exhibited, For example, it can be set as an annular | circular shaped convex part. More specifically, the shape of the first valve seat portion 172 can be a shape in which the valve seat surface is inclined from the opening portion of the discharge through hole 174 toward the bottom surface of the flow rate reducing recess portion 171. . A communication groove 173 that connects the inside of the flow rate reducing recess 171 and the discharge through-hole 174 is formed in a part of the region where the first diaphragm portion 175 of the first valve seat portion 172 can be in close contact.

  The flow rate reducing through hole 161 connected to the first pressure reducing groove 133 (first pressure reducing channel 142) and the first connection hole 176 communicating with the second connection groove 135 (second connecting channel 145) are used for reducing the flow rate. The bottom surface of the recess 171 is formed in a region where the first valve seat 172 is not disposed.

  The first diaphragm portion 175 is a part of the film 124. When the film 124 is joined to the emitter body 120, the first diaphragm portion 175 is arranged so as to partition the inside of the flow rate reducing recess 171 and the inside of the tube 110, and covers the upper surface of the flow rate reducing recess 171. A part of the flow path wall in the flow rate reducing portion 136 is formed. The first diaphragm portion 175 is deformed so as to contact the first valve seat portion 172 in accordance with the pressure of the irrigation liquid in the tube 110. Specifically, the first diaphragm portion 175 deforms toward the first valve seat portion 172 as the pressure of the irrigation liquid increases, and eventually comes into contact with the first valve seat portion 172. Even if the first diaphragm portion 175 is in close contact with the first valve seat portion 172, the first diaphragm portion 175 does not block the flow rate reducing through hole 161, the discharge through hole 174, and the communication groove 173. The irrigation liquid sent from the flow rate reducing through-hole 161 can be sent to the discharge section 138 through the communication groove 173 and the discharge through-hole 174. Note that the first diaphragm portion 175 is disposed adjacent to a second diaphragm portion 183 described later.

  The channel opening / closing part 137 is disposed in the second channel 146 between the second decompression channel 144 (second decompression groove 134) and the second connection groove 135 (second connection channel 145), The emitter body 122 is disposed on the first surface 120a side. The channel opening / closing unit 137 opens the second channel 146 according to the pressure in the tube 110 and sends the irrigation liquid to the discharge unit 138. The downstream of the channel opening / closing unit 137 is connected to the flow rate reducing unit 136 through the second connection groove 135 (second connection channel 145), and the irrigation liquid from the second decompression channel 144 (second decompression groove 134). Reaches the discharge part 138 through the second connection groove 135 (second connection flow path 145) and the flow rate reduction part 136. The channel opening / closing part 137 includes a channel opening / closing through hole 163 communicating with the second decompression channel 144 (second decompression groove 134), a channel opening / closing recess 181, a second valve seat 182, and a film 124. 2nd diaphragm part 183 and 2nd connection hole 184 connected to the 2nd connection slot 135 (2nd connection channel 145).

  The shape of the channel opening / closing recess 181 in plan view is substantially circular. On the bottom surface of the channel opening / closing recess 181, there are a channel opening / closing through hole 163, a second valve seat portion 182, and a second connection hole 184 communicating with the second connection groove 135 (flow rate reducing portion 136). Has been placed. The bottom surface of the channel opening / closing recess 181 is disposed closer to the first surface 120 a than the bottom surface of the flow rate reducing recess 171. That is, the channel opening / closing recess 181 is formed shallower than the flow rate reducing recess 171. The top portion of the second valve seat portion 182 is disposed on the first surface 120 a side from the top portion of the first valve seat portion 172. Accordingly, when the film 124 is deformed by the pressure of the irrigation liquid, the film 124 comes into contact with the second valve seat portion 182 before the first valve seat portion 172. The planar shape of the channel opening / closing recess 181 may be the same size and the same shape as the flow rate reducing recess 171 or may be smaller than the flow rate reducing recess 171. The flow rate reducing recess 171 and the flow path opening / closing recess 181 are arranged side by side in the major axis direction of the emitter body 122. The irrigation liquid that has flowed from the second decompression flow path 144 through the flow path opening / closing through-hole 163 into the flow path opening / closing recess 181 has the second connection hole 184, the second connection flow path 145, and the first connection hole 176. To flow into the flow rate reduction unit 136.

  The channel opening / closing through hole 163 communicating with the second pressure reducing groove 134 is formed in the bottom surface of the channel opening / closing recess 181 in a region where the second valve seat 182 is not disposed. A second opening / closing through-hole 163 communicating with the second decompression groove 134 is disposed so as to be surrounded by the second valve seat portion 182, and a second communicating with the second connection groove 135 (second connection channel 145). The connection hole 184 may be disposed outside the second valve seat portion 182.

  The second valve seat portion 182 is disposed on the bottom surface of the flow path opening / closing recess 181 so as to surround the second connection hole 184. Further, the second valve seat portion 182 faces the second diaphragm portion 183 and is disposed in a non-contact manner. When the film 124 is deformed by the pressure of the irrigation liquid flowing through the tube 110, the second diaphragm portion 183 is in close contact with the second valve seat portion 182. It is formed to be able to. At this time, the second diaphragm portion 183 is in close contact with the second valve seat portion 182 to close the flow passage opening / closing through hole 163, and as a result, closes the second flow passage 146. The shape of the 2nd valve seat part 182 will not be specifically limited if the above-mentioned function can be exhibited. In the present embodiment, the second valve seat 182 is a part of the bottom surface of the channel opening / closing recess 181 provided with the channel opening / closing through hole 163. The second valve seat portion 182 may be an annular convex portion disposed so as to surround the second connection hole 184.

  The second diaphragm portion 183 is a part of the film 124 and is disposed adjacent to the first diaphragm portion 175. When the film 124 is joined to the emitter main body 120, the second diaphragm portion 183 is arranged so as to partition the inside of the channel opening / closing recess 181 and the inside of the tube 110, and the upper surface of the channel opening / closing recess 181 is formed. A part of the flow path wall in the flow rate reducing portion 136 is covered. The second diaphragm portion 183 is deformed so as to contact the second valve seat portion 182 according to the pressure of the irrigation liquid in the tube 110. Specifically, the second diaphragm portion 183 deforms toward the second valve seat portion 182 and contacts the second valve seat portion 182 as the pressure of the irrigation liquid increases. Thereby, the 2nd flow path 146 (2nd connection hole 184) is obstruct | occluded.

  The ejection unit 138 is disposed on the second surface 120b side of the emitter body 122. The discharge unit 138 sends the irrigation liquid from the discharge through-hole 174 to the discharge port 112 of the tube 110. The configuration of the discharge unit 138 is not particularly limited as long as the above function can be exhibited. In the present embodiment, the discharge unit 138 includes a discharge recess 191 and an intrusion prevention unit 192.

  The discharge recess 191 is disposed on the second surface 120 b side of the emitter body 122. The shape of the discharge recess 191 in plan view is substantially rectangular. A discharge through hole 174 and an intrusion prevention portion 192 are disposed on the bottom surface of the discharge recess 191.

  The intrusion prevention unit 192 prevents entry of foreign matter from the discharge port 112. The intrusion prevention unit 192 is not particularly limited as long as it can exhibit the above-described function. In the present embodiment, the intrusion prevention unit 192 has a plurality of ridges 193 arranged adjacent to each other. The plurality of ridges 193 are disposed so as to be positioned between the discharge through hole 174 and the discharge port 112 when the emitter body 122 (emitter 120) is joined to the tube 110.

  The film 124 has a first diaphragm portion 175 and a second diaphragm portion 183, and constitutes the upper surface (flow channel wall) of the flow rate reducing portion 136 and the flow channel opening / closing portion 137 when joined to the emitter body 122. The thickness of the film 124 is 0.3 mm, for example.

  The hinge portion 126 is connected to a part of the first surface 120 a of the emitter body 122. The hinge portion 126 has the same thickness as the film 124 and is formed integrally with the emitter body 122 and the film 124. The film 124 may be prepared as a separate body from the emitter body 122 and bonded to the emitter body 122.

(Operation of drip irrigation tube and emitter)
Next, the operation of the drip irrigation tube 100 will be described. First, irrigation liquid is fed into the tube 110. Examples of irrigation liquids include water, liquid fertilizers, pesticides and mixtures thereof. The pressure of the irrigation liquid fed 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 131. Specifically, the irrigation liquid in the tube 110 enters the water intake recess 153 through the gap between the first ridges 155 and passes through the water intake through hole 152. At this time, since the water intake part 131 has the screen part 151 (gap between the 1st protruding item | lines 155), the suspended | floating matter in the irrigation liquid can be removed. Moreover, since the so-called wedge wire structure is formed in the water intake part 131, the pressure loss of the water at the time of taking-in of the water to the water intake part 131 is suppressed.

  The irrigation liquid taken from the water intake unit 131 reaches the first connection channel 141. The irrigation liquid that has reached the first connection channel 141 flows into the first decompression channel 142 and the second decompression channel 144.

  The irrigation liquid that has flowed into the first decompression flow path 142 reaches the flow rate reduction unit 136 through the flow rate reduction through-hole 161. The irrigation liquid that has flowed into the flow rate reduction unit 136 flows into the discharge unit 138. The irrigation liquid that has flowed into the discharge unit 138 is discharged from the discharge port 112 of the tube 110 to the outside of the tube 110.

  On the other hand, the irrigation liquid that has flowed into the second decompression channel 144 flows into the channel opening / closing part 137 through the channel opening / closing through hole 163. The irrigation liquid that has flowed into the flow path opening / closing unit 137 flows into the discharge unit 138 through the flow rate reducing unit 136. The irrigation liquid that has flowed into the discharge unit 138 is discharged from the discharge port 112 of the tube 110 to the outside of the tube 110.

  As described above, the flow rate reducing unit 136 and the flow path opening / closing unit 137 communicate with each other. Further, in the flow rate reduction unit 136, the flow rate of the irrigation liquid is controlled by the first diaphragm unit 175 according to the pressure of the irrigation liquid in the tube 110, and in the flow path opening / closing unit 137, the irrigation liquid in the tube 110 is controlled. The flow rate of the irrigation liquid is controlled by the second diaphragm unit 183 in accordance with the pressure. Therefore, the operation of the flow path opening / closing unit 137 and the flow rate reducing unit 136 according to the pressure of the irrigation liquid in the tube 110 will be described.

  Before the irrigation liquid is fed into the tube 110, the pressure of the irrigation liquid is not applied to the film 124, so the first diaphragm portion 175 and the second diaphragm portion 183 are not deformed.

  When the pressure of the irrigation liquid is low, the irrigation liquid is discharged out of the tube through both the first flow path 143 and the second flow path 146. As the pressure of the irrigation liquid increases, the first diaphragm portion 175 deforms toward the first valve seat portion 172 and the second diaphragm portion 183 deforms toward the second valve seat portion 182. When the pressure of the irrigation liquid increases, the second diaphragm portion 183 comes into contact with the second valve seat portion 182 and the second flow path 146 is closed. When the second flow path 146 is closed, the irrigation liquid is discharged only through the first flow path 143. As described above, when the pressure of the irrigation liquid is further increased, the flow rate of the irrigation liquid from the flow rate reduction unit 136 is controlled to a flow rate according to the passage amount of the first flow path 143, and from the discharge port, the first flow rate is increased. Only the irrigation liquid having a flow rate corresponding to the passage amount of the flow path 143 is discharged.

  When the pressure of the irrigation liquid in the tube is further increased, the first diaphragm portion 175 is further deformed toward the first valve seat portion 172 and eventually comes into close contact with the valve seat surface of the first valve seat portion 172. In the emitter 120, since the valve seat surface of the first valve seat portion 172 is inclined downward toward the outer edge, the first diaphragm portion 175 has the valve seat as the pressure of the irrigation liquid increases. The flow path formed by the communication groove 173 and the first diaphragm portion 175 is gradually lengthened, and the opening on the outer edge side is gradually narrowed. As described above, when the pressure of the irrigation liquid is further increased, the flow rate of the irrigation liquid from the flow rate reduction unit 136 is controlled to a flow rate according to the opening area of the flow path, and finally from the discharge port, Only irrigation liquid with a flow rate corresponding to the opening area is discharged.

  As described above, the emitter 120 increases the flow rate of the irrigation liquid due to the pressure of the irrigation liquid, and blocks the second flow path 146 and decreases the opening area of the flow path in the first flow path 143. Since the decrease in the flow rate is offset, the amount of the irrigation liquid discharged from the discharge port does not increase even when the pressure of the irrigation liquid increases. Therefore, the drip irrigation tube 100 can discharge a certain amount of irrigation liquid out of the tube 110 regardless of whether the pressure of the irrigation liquid is low or high.

(Emitter manufacturing method)
In the present invention, as shown in FIG. 7 which is an enlarged view of a region F indicated by a broken line in FIG. 6 and FIG. 6, the emitter body 122 insert-molds and injects an intermediate molded body 222 having substantially the same shape as the emitter body 122. It is manufactured by using a mold by a method such as molding and compression molding, and then plastically deforming the intermediate molded body 222 into the shape of the emitter body 122 by secondary processing.

  The intermediate molded body 222 has provisional ridges 256 whose height from the bottom surface of the water intake recess 153 is higher than that of the first ridges 155 at each position where the first ridges 155 are disposed.

  It is preferable that the temporary convex stripe 256 does not have an overhanging portion that becomes an undercut. Thereby, since the temporary protruding item | line 256 does not become an undercut which requires unreasonable removal, it is easy to release by pulling out from a metal mold | die. For this reason, the intermediate molded body 222 having such provisional ridges 256 is unlikely to be deformed or damaged during release. At this time, the provisional ridge 256 has a width in the height direction (thickness direction of the intermediate molded body 222) (a width from the second surface 120b side to the first surface 120a side when the emitter body 122 is secondarily processed). You may form so that it may have the substantially rectangular parallelepiped area | region which does not change in at least one part of the height direction. Further, the provisional ridge 256 has at least a part in the height direction in a width reduction region in which the width on the first surface 120a side becomes narrower than the second surface 120b side when the emitter body 122 is secondarily processed. You may form so that it may have. In other words, the provisional ridge 256 has the first surface at any two points when the width in the major axis direction of the intermediate formed body 222 (same as the major axis direction of the emitter 120) is measured at two arbitrary points. The width on the 120a side and the width on the second surface 120b side may be the same, or the first surface 120a side may be formed to be narrower than the second surface 120b side. Among these, the provisional protrusion 256 is formed so that the width on the first surface 120a side is narrower than that on the second surface 120b side from the viewpoint of easier release from the mold. It is preferable that there is no widened region in the height direction in which the width on the first surface 120a side is wider than the second surface 120b side when the emitter body 122 is secondarily processed.

  In addition, since the area | region of the bottom face side of the recessed part 153 for water intake among the temporary protrusions 256 is hard to deform | transform at the time of a secondary process, it is the substantially same shape as the said area | region in the 1st protrusion 155 of the emitter 120 to manufacture. It is preferable.

  The intermediate molded body 222 is preferably formed integrally with the hinge portion 126 and the film 124.

  Thereafter, the intermediate molded body 222 having the provisional ridges 256 is plastically deformed into the shape of the emitter body 122 by secondary processing. Specifically, the intermediate protrusion 222 is plastically deformed into the shape of the emitter body 122 by plastically deforming the temporary protrusions 256 to form the first protrusions 155 constituting the wedge wire structure.

  The plastic deformation is such that the width of the first ridge 155 at the top of the emitter body 122 on the first surface 120a side is larger than the width of the first ridge 155 at an arbitrary height on the second surface 120b side. What is necessary is just to carry out by the method which can carry out the plastic deformation of the top part of the temporary protruding item | line 256, and can make it spread in the width direction. For example, the plastic deformation can be performed by a method such as hot plate pressing, physical compression and ultrasonic pressing. Among these methods, the hot plate press is preferable because the plastic deformation of the top of the provisional ridge 256 can be performed inexpensively and effectively.

  The emitter 120 is then configured by rotating the film 124 around the hinge 126 and joining the film 124 to the first surface 120a of the emitter body 122. The joining method of the emitter body 122 and the film 124 is not particularly limited. Examples of the method for joining the emitter body 122 and the film 124 include welding of a resin material constituting the film 124 and adhesion with an adhesive. The hinge portion 126 may be cut after the emitter body 122 and the film 124 are joined. The film 124 may be prepared as a separate body from the emitter body 122 and bonded to the emitter body 122.

(effect)
According to the manufacturing method described above, deformation and breakage of the first ridge 155 (temporary ridge 256) at the time of releasing from the mold can be suppressed.

  Moreover, according to the manufacturing method mentioned above, the shape of the wedge wire structure by the 1st protruding item | line 155 can be adjusted more easily by changing the height of the temporary protruding item | line 256 and the degree of plastic deformation. In other words, according to the manufacturing method described above, the width at the top of the first ridge 155 and an arbitrary height on the second surface 120b side are suppressed while suppressing the breakage and deformation of the first ridge 155 at the time of manufacture. It is also easy to increase the ratio of the width at. Therefore, according to the manufacturing method described above, it is possible to manufacture an emitter in which suspended matter in the irrigation liquid is less likely to enter the inside and the pressure loss of water that has entered the intake portion 131 is less.

(First Modification of Emitter Manufacturing Method)
As shown in FIG. 8, the intermediate molded body 222 has a cut portion 257 provided with a cut in a direction substantially orthogonal to the arrangement direction of the plurality of temporary convex stripes 256 when viewed from above at the top of the temporary convex stripes 256. You may have. The provisional ridge 256 having the cut portion 257 opens in the direction of the adjacent temporary ridge 256 from the cut portion 257 during plastic deformation (particularly during physical compression), so that the shape of the wedge wire structure is easier. Can be produced.

(Second Modification of Emitter Manufacturing Method)
In the manufacturing method described above, the intermediate molded body 222 is plastically deformed into the shape of the emitter body 122 and then the film 124 is bonded to the first surface 120a of the emitter body 122. However, the plastic deformation of the intermediate molded body 222 and the bonding of the film 124 are performed. May be performed as the same process. In other words, at the time of heating for welding the resin material constituting the film 124 or bonding with an adhesive, it is possible to simultaneously hot plate press the provisional ridge 256 and plastically deform it into the shape of the first ridge 155. is there. Therefore, according to this modification, the emitter manufacturing process can be shortened, and the emitter can be efficiently manufactured in a shorter time.

  The shape of the emitter 120 is not limited to the above description, and the present invention is applicable to any shape of the emitter 120 having the first protrusion 155 constituting the wedge wire structure in the water intake portion 131. Is possible.

  Further, when the second ridge 156 constitutes a wedge wire structure, an intermediate molded body having temporary ridges is formed at each position where the second ridge 156 of the emitter body 122 is disposed, and the temporary protrusion is formed. The strip may be plastically deformed to form the second ridge 156.

  According to the present invention, when the emitter is manufactured, the screen portion having the wedge wire structure is not easily damaged, and the design of the wedge wire structure at the time of manufacturing the emitter is increased. It is possible to manufacture an emitter in which the amount of dripping is not likely to change unintentionally and the pressure loss of water entering the inside of the water intake portion is less because it is less likely to enter the inside. Therefore, according to the present invention, it is expected that the emitter will be spread to a technical field that requires long-term dripping, and further development of the technical field will be expected.

100 Tube for drip irrigation 110 Tube 112 Discharge port 120 Emitter 120a First surface 120b Second surface 122 Emitter body 124 Film 126 Hinge portion 131 Water intake portion 132 First connection groove 133 First pressure reduction groove 134 Second pressure reduction groove 135 Second connection Groove 136 Flow reduction part 137 Flow path opening / closing part 138 Discharge part 141 First connection flow path 142 First pressure reduction flow path 143 First flow path 144 Second pressure reduction flow path 145 Second connection flow path 146 Second flow path 151 Screen part 152 Water intake through-hole 153 Water intake recess 154 Projection 155 First projecting strip 156 Second projecting strip 161 Flow reduction through-hole 162 Projection 163 Flow channel opening / closing through-hole 171 Flow rate decrease recess 172 First valve seat 173 Communication groove 174 Discharge through hole 175 First diaphragm portion 176 First connection hole 18 DESCRIPTION OF SYMBOLS 1 Flow path opening / closing recessed part 182 2nd valve seat part 183 2nd diaphragm part 184 2nd connection hole 191 Discharge recessed part 192 Intrusion prevention part 193 Projection part 222 Intermediate molded object 256 Temporary projection 257 Cut part

Claims (5)

It is an inner wall surface of a tube through which the irrigation liquid is circulated, and is joined to a position corresponding to a discharge port communicating between the inside and the outside of the tube, and quantitatively discharges the irrigation liquid in the tube from the discharge port. A method of manufacturing an emitter for discharging to
The emitter is
A water intake portion for taking in the irrigation liquid, provided on the first surface side of the emitter body having a first surface and a second surface that are in reverse relation to each other;
A discharge part provided on the second surface side of the emitter body, and capable of discharging the irrigation liquid to the outside of the tube when arranged facing the discharge port;
A channel for connecting the water intake unit and the discharge unit and circulating the irrigation liquid,
The water intake portion has a screen portion on which a plurality of protrusions formed so as to be wider on the first surface side than on the second surface side are arranged,
The manufacturing method includes:
A step of producing an intermediate molded body of the emitter having a plurality of provisional ridges having a height higher than the ridges of the emitter at respective positions where the ridges of the water intake section are disposed;
Forming the plurality of ridges by plastically deforming the plurality of provisional ridges;
A method for manufacturing an emitter, comprising:   The step of producing the intermediate molded body is formed such that the width on the first surface side is the same as the width on the second surface side, or the width on the first surface side is narrower than that on the second surface side. The method for manufacturing an emitter according to claim 1, which is a step of manufacturing an intermediate formed body having a plurality of provisional ridges.   The step of producing the intermediate molded body includes an intermediate molded body having a cut portion provided with a cut in a direction perpendicular to the arrangement direction of the plurality of convex strips on the upper end surface of the temporary convex strip on the first surface side. The method of manufacturing an emitter according to claim 1, wherein The emitter further includes a film disposed on the first surface and constituting at least a part of a channel wall of the channel,
The method of manufacturing an emitter according to any one of claims 1 to 3, wherein the step of forming the ridge is performed integrally with the pressure bonding of the film. The method for manufacturing an emitter according to claim 4, wherein the film is integrally formed with the intermediate molded body in the step of producing the intermediate molded body.

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