Abstract:
Provided is an emitter ( 120 ) comprising a flow path that leads from an intake path ( 221 ) for taking in irrigation liquid that is within a tube to a recessed section ( 252 ). The flow path comprises opening/closing sections ( 248 ) that are arranged with a gap ( 249 ) therebetween. The gap ( 249 ) communicates with a discharge section. When the opening/closing sections ( 248 ) are pushed by the pressure of the irrigation fluid within a recessed section ( 242 ), the tip sections of each of the opening/closing sections ( 248 ) are brought into contact and one part of the gap ( 249 ) is blocked. The flow rate of the irrigation fluid within the emitter ( 120 ) is controlled by the remaining amount of said irrigation fluid that is capable of passing through the gap ( 249 ).

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an emitter and a trickle irrigation tube including the emitter. 
       BACKGROUND ART 
       [0002]    A trickle irrigation method is known as a method for culturing plants. In the trickle irrigation method, for example, a trickle irrigation tube is disposed on the soil in which plants are planted, and irrigation liquid such as water and liquid fertilizer is slowly supplied from the trickle irrigation tube to the soil. The trickle irrigation method can minimize the consumption amount of the irrigation liquid, and has been increasingly attracting attention in recent years. 
         [0003]    The trickle irrigation tube typically has a tube and an emitter (also called “dripper”). The emitter typically supplies the soil with the irrigation liquid in the tube at a predetermined rate at which the irrigation liquid is dropped to the soil. Emitters which are pierced into the tube from the outside, and emitters joined to the inner wall surface of the tube are known. 
         [0004]    For example, the latter emitter has a channel including a pressure reduction channel for allowing the irrigation liquid having entered the emitter from the internal space of the tube toward the through hole of the tube while reducing the pressure of the liquid, and a diaphragm part configured to change the volume of a portion of the channel where the irrigation liquid having reduced pressure flows in accordance with the pressure of the liquid in the tube. The emitter is composed of a member which is joined to the inner wall surface of the tube, a member which is disposed on the member joined to the inner wall surface, and a diaphragm part which is disposed between the two members. The diaphragm part is composed of an elastic film such as a silicone rubber film (see, for example, PTL 1). 
         [0005]    The emitter can suppress variation of the discharge rate of the irrigation liquid regardless of change of the pressure of the irrigation liquid in the tube. Therefore, the emitter is advantageous from the viewpoint of uniformly growing multiple plants. 
       CITATION LIST 
     Patent Literature 
     PTL 1 
     Japanese Patent Application Laid-Open No. 2010-46094 
     SUMMARY OF INVENTION 
     Technical Problem 
       [0006]    The emitter is formed by assembling three components. In view of this, the emitter may cause assembling error. In particular, the assembling error of the diaphragm part may cause variation of the operation of the diaphragm part, and variation of the discharge rate of the irrigation liquid. 
         [0007]    In addition, the emitter is typically a molded article of an inexpensive resin such as polyethylene and polypropylene, and the diaphragm part is composed of a more expensive elastic material such as a silicone rubber film. The use of components of different materials has a room for improvement in material cost reduction. 
         [0008]    Generally, in a trickle irrigation tube, hundreds of emitters are disposed in one tube in some cases. In a long trickle irrigation tube, the supply pressure of irrigation liquid to the tube is required to be increased, and consequently the discharge rate of the irrigation liquid of the emitter may not be stable. In view of this, control of the discharge rate of the irrigation liquid of the emitter in accordance with the pressure of the irrigation liquid in the tube is desired. 
         [0009]    Furthermore, from the viewpoint of reducing the material cost and the manufacturing cost of the emitter, an emitter which can be manufactured with a single inexpensive material and fewer number of components is desired. 
         [0010]    An object of the present invention is to provide an emitter which can stabilize the discharge rate of the irrigation liquid and can further reduce the manufacturing cost. In addition, another object of the present invention is to provide a trickle irrigation tube having the emitter. 
       Solution to Problem 
       [0011]    The present invention provides an emitter to be disposed on a tube for allowing irrigation liquid to flow therethrough, the emitter being configured for quantitatively discharging the irrigation liquid in the tube to outside of the tube, the emitter including: an intake part for receiving the irrigation liquid in the tube; a pressure reduction channel for allowing the irrigation liquid received from the intake part to flow therethrough while reducing a pressure of the irrigation liquid; a flow rate controlling part for controlling a flow rate of the irrigation liquid supplied from the pressure reduction channel in accordance with a pressure of the irrigation liquid supplied from the pressure reduction channel; a discharging part configured to be supplied with the irrigation liquid which is to be discharged to the outside of the tube and has a flow rate controlled by the flow rate controlling part. The flow rate controlling part includes a gap opening in a linear shape at a channel on a downstream side of the pressure reduction channel and communicated with the discharging part, a movable part having flexibility and including a free end facing the gap and a fixed end, the fixed end having a straight line shape and connecting both ends of the gap, and a protrusion protruding along the free end from the movable part toward the channel on the downstream side; and, when the pressure of the irrigation liquid in the channel is equal to or higher than a predetermined value, the movable part bends and the protrusion reduces a channel area of a channel of the irrigation liquid constituted by the gap. 
         [0012]    Furthermore, the present invention provides a trickle irrigation tube of an embodiment of the present invention which includes: a tube; and at least one emitter disposed on the tube, the emitter being the above-mentioned emitter 
       Advantageous Effects of Invention 
       [0013]    The emitter according to the present invention controls the discharge rate of the irrigation liquid in accordance with the pressure of the irrigation liquid in the trickle irrigation tube, and thus can stabilize the discharge rate of the irrigation liquid. In addition, since the emitter according to the present invention can be formed with one or two components by injection molding of a resin material, the manufacturing cost can be further reduced in comparison with conventional emitters composed of three parts. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0014]      FIG. 1  is a schematic sectional view of a trickle irrigation tube according to a first embodiment of the present invention; 
           [0015]      FIG. 2A  illustrates a top surface, a front surface and a side surface of an emitter according to the embodiment, and  FIG. 2B  illustrates a bottom surface, a front surface and a side surface of the emitter; 
           [0016]      FIG. 3A  is a plan view of the emitter according to the embodiment,  FIG. 3B  is a back view of the emitter, and  FIG. 3C  is a side view of the emitter; 
           [0017]      FIG. 4A  is a sectional view of the emitter according to the embodiment taken along line A-A of  FIG. 3A , and  FIG. 4B  is a sectional view of the emitter taken along line B-B of  FIG. 3A ; 
           [0018]      FIG. 5A  is a bottom view of the emitter according to the embodiment, and  FIG. 5B  is a sectional view of the emitter taken along line A-A of  FIG. 5A ; 
           [0019]      FIG. 6A  illustrates a top surface, a front surface and a side surface of the emitter according to the embodiment in the state before a film is joined to an emitter main body, and  FIG. 6B  illustrates a bottom surface, a front surface and a side surface of the emitter; 
           [0020]      FIG. 7A  is a plan view of the emitter according to the embodiment in the state before a film is joined to the emitter main body,  FIG. 7B  is a rear view of the emitter, and  FIG. 7C  is a side view of the emitter; 
           [0021]      FIG. 8A  is a sectional view of the emitter according to the embodiment taken along line A-A of  FIG. 7A  in the state before the film is joined to emitter the main body, and  FIG. 8B  is a sectional view of the emitter taken along line B-B of  FIG. 7A ; 
           [0022]      FIG. 9A  is a bottom view of the emitter according to the embodiment in the state before the film is joined to an emitter main body, and  FIG. 9B  is a sectional view of the emitter taken along line A-A of  FIG. 9A ; 
           [0023]      FIG. 10A  illustrates part A of  FIG. 4B  in an enlarged manner in the case where the pressure of the irrigation liquid in the tube is equal to or higher than a first pressure value and lower than a second pressure value,  FIG. 10B  illustrates part A of  FIG. 4B  in an enlarged manner in the case where the pressure of the irrigation liquid in the tube is equal to or higher than the second pressure value and lower than the third pressure value, and  FIG. 10C  illustrates part A of  FIG. 4B  in an enlarged manner in the case where the pressure of the irrigation liquid in the tube is equal to or higher than the third pressure value; 
           [0024]      FIG. 11  is a schematic sectional view of a trickle irrigation tube according to a second embodiment of the present invention; 
           [0025]      FIG. 12A  is a perspective view of the emitter according to the embodiment as viewed from the tube side, and  FIG. 12B  is a perspective view of the emitter as viewed from a side opposite to the tube; 
           [0026]      FIG. 13A  is a plan view of the emitter according to the embodiment,  FIG. 13B  is a front view of the emitter,  FIG. 13C  is a bottom view of the emitter, and  FIG. 13D  is a side view of the emitter; 
           [0027]      FIG. 14A  is a sectional view of the emitter according to the embodiment taken along line A-A of  FIG. 13A , and  FIG. 14B  is a sectional view of the emitter taken along line B-B of  FIG. 13A ; 
           [0028]      FIG. 15A  is a plan view of a first member according to the embodiment,  FIG. 15B  is a front view of the first member, and  FIG. 15C  is a bottom view of the first member; 
           [0029]      FIG. 16A  is a sectional view of the first member according to the embodiment taken along line A-A of  FIG. 15A , and  FIG. 16B  is a sectional view of the first member taken along line B-B of  FIG. 15A ; 
           [0030]      FIG. 17A  is a plan view of a second member according to the embodiment,  FIG. 17B  is a front view of the second member,  FIG. 17C  is a bottom view of the second member, and  FIG. 17D  is a side view of the second member; 
           [0031]      FIG. 18  is a sectional view of the second member according to the embodiment taken along line A-A of  FIG. 17A ; 
           [0032]      FIG. 19A  illustrates part A of  FIG. 14A  in an enlarged manner in the case where the pressure of the irrigation liquid in the tube is equal to or higher than a first pressure value and lower than a second pressure value,  FIG. 19B  illustrates part A of  FIG. 14A  in an enlarged manner in the case where the pressure of the irrigation liquid in the tube is equal to or higher than the second pressure value and lower than the third pressure value, and  FIG. 19C  illustrates part A of  FIG. 14A  in an enlarged manner in the case where the pressure of the irrigation liquid in the tube is equal to or higher than the third pressure value; 
           [0033]      FIG. 20A  schematically illustrates a first modification of a discharging part of the emitter according to the embodiment, and  FIG. 20B  schematically illustrates a second modification of the discharging part; and 
           [0034]      FIG. 21A  is a sectional view schematically illustrating a first modification of a protrusion of the first and second embodiments of the present invention, and  FIG. 21B  is a sectional view schematically illustrating a second modification of the protrusion. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0035]    In the following, embodiments of the present invention are described in detail with reference to the accompanying drawings. It is to be noted that the shapes in plan view, the size, the angle and the pressure in the following embodiments are merely examples, and may be appropriately changed as long as desired functions of the components of the embodiments are achieved. 
       Embodiment 1 
     Configuration 
       [0036]      FIG. 1  is a schematic sectional view of a trickle irrigation tube according to Embodiment 1 of the present invention. Trickle irrigation tube  100  is composed of tube  110  and emitter  120 . Tube  110  is made of polyethylene, for example. Emitter  120  is disposed at a predetermined interval (for example, 200 to 500 mm) in the axial direction of tube  110 . Each emitter  120  is joined on the inner wall surface of tube  110 . Emitter  120  is disposed at a position where emitter  120  covers discharge port  130  of tube  110 . Discharge port  130  is a hole which extends through the tube wall of tube  110 . The hole diameter of discharge port  130  is, for example, 1.5 mm. It is to be noted that arrow F indicates the direction of flow of the irrigation liquid in tube  110 . 
         [0037]      FIG. 2A  illustrates a top surface, a front surface and a side surface of emitter  120 , and  FIG. 2B  illustrates a bottom surface, a front surface and a side surface of emitter  120 . In addition,  FIG. 3A  is a plan view of emitter  120 ,  FIG. 3B  is a rear view of emitter  120 , and  FIG. 3C  is a side view of emitter  120 . In addition,  FIG. 4A  is a sectional view of emitter  120  taken along line A-A of  FIG. 3A , and  FIG. 4B  is a sectional view of emitter  120  taken along line B-B of  FIG. 3A . In addition,  FIG. 5A  is a bottom view of emitter  120 , and  FIG. 5B  is a sectional view of emitter  120  taken along line A-A of  FIG. 5A . It is to be noted that the X direction is the axial direction of tube  110  or the longitudinal direction of emitter  120 , the Y direction is the short (width) direction of emitter  120 , and the Z direction is the height direction of emitter  120 . In addition, the direction of arrow F is parallel to the X direction. 
         [0038]    As illustrated in  FIG. 2A  and  FIG. 2B , emitter  120  has a cuboid-like external shape. For example, the length of emitter  120  is 30 mm in the X direction, 10 mm in the Y direction, and 3 mm in the Z direction. Emitter  120  includes emitter main body  200  to be joined to the inner wall surface of tube  110 , and film  300  which is formed integrally with emitter main body  200 . 
         [0039]      FIG. 6A  illustrates a top surface, a front surface and a side surface of emitter  120  in the state before film  300  is joined to emitter main body  200 , and  FIG. 6B  illustrates a bottom surface, a front surface and a side surface of emitter  120 . In addition,  FIG. 7A  is a plan view of emitter  120  in the state before film  300  is joined to emitter main body  200 ,  FIG. 7B  is a rear view of the emitter  120 , and  FIG. 7C  is a side view of the emitter  120 . Further,  FIG. 8A  is a sectional view of emitter  120  taken along line A-A of  FIG. 7A  in the state before film  300  is joined to emitter main body  200 , and  FIG. 8B  is a sectional view of the emitter  120  taken along line B-B of  FIG. 7A . In addition,  FIG. 9A  is a bottom view of emitter  120  in the state before film  300  is joined to emitter main body  200 , and  FIG. 9B  is a sectional view of the emitter  120  taken along line A-A of  FIG. 9A . 
         [0040]    As illustrated in  FIG. 3B  and  FIG. 3C , emitter main body  200  includes first surface  201  and second surface  202 . First surface  201  is one surface which is joined to film  300  in the Z direction of emitter main body  200 . Second surface  202  is the other surface which is joined to the inner wall surface of tube  110  in the Z direction of emitter main body  200 . 
         [0041]    As illustrated in  FIG. 6A ,  FIG. 6B ,  FIG. 7A  and  FIG. 8A , emitter main body  200  includes recesses  211  and  212  formed on first surface  201 , linear protrusions  213  and  214  disposed in recesses  211  and  212 , intake channel  221  extending through emitter main body  200  in the Z direction, and flow rate regulation valve  223  disposed in intake channel  221 . 
         [0042]    As illustrated in  FIG. 6A  and  FIG. 7A , recess  211  is a recess located at a center portion of first surface  201 . The shape (hereinafter also referred to as “shape in plan view”) of recess  211  as viewed from the Z direction is a rectangular shape. 
         [0043]    Recess  212  is a recess located at first surface  201  and configured to connect recess  211  and intake channel  221 . As illustrated in  FIG. 7B , the length of recess  212  in the Y direction is equal to the diameter of an opening part of intake channel  221  described later. 
         [0044]    As illustrated in  FIG. 6A  and  FIG. 7A , linear protrusions  213  are a plurality of linear protrusions disposed in recess  211  side by side in the X direction, and the longitudinal direction of protrusions  213  is aligned in the Y direction. In plan view, linear protrusion  213  has a rectangular shape. A gap is provided between linear protrusions  213  in the X direction, and between linear protrusion  213  and the wall surface of recess  211  in the Y direction. 
         [0045]    Linear protrusions  214  are a plurality of linear protrusions disposed side by side in the Y direction in recess  212 , and the longitudinal direction of linear protrusions  214  is aligned with the X direction. In plan view, linear protrusion  214  has a shape which is obtained by cutting out one end of a rectangular in an arc shape. A gap is provided between linear protrusions  214  in the Y direction, and between an end of linear protrusion  214  and linear protrusion  213  adjacent to linear protrusion  214  in the X direction. 
         [0046]    The distance from the bottom surface of recesses  211  and  212  to the tip end surface of linear protrusions  213  and  214  (the height of linear protrusion  213  and linear protrusion  214 , which is the depth of recesses  211  and  212 ) is, for example, 0.5 mm. 
         [0047]    The shape of the opening of intake channel  221  at first surface  201  is a circular shape as illustrated in  FIG. 7A . Intake channel  221  has an opening diameter of, for example, 5 mm. As illustrated in  FIG. 9A , the shape of the opening of intake channel  221  at second surface  202  is a shape (bell shape) which is formed with a semicircle of the above-mentioned circle and a rectangular which has a width of the diameter of the opening and extends in the Y direction from the diameter of the semicircle. 
         [0048]    As illustrated in  FIG. 7A  and  FIG. 9A , flow rate regulation valve  223  is composed of four flexible opening-closing parts which close intake channel  221 . As illustrated in  FIG. 8A  and  FIG. 9A , the opening-closing parts have a form in which a substantially hemisphere thin dome protruding from first surface  201  side toward second surface  202  side is divided with slits in a cross shape. The opening-closing part has a thickness of, for example, 0.5 mm, and, normally, the slit has a width of, for example, 0 mm. 
         [0049]    As illustrated in  FIG. 6B ,  FIG. 9A  and  FIG. 9B , emitter main body  200  further includes, on second surface  202 , three grooves  231 ,  232  and  233  and hole  234  communicating between groove  233  and the first surface  201  side. 
         [0050]    As illustrated in  FIG. 5A  and  FIG. 9A , groove  231  is connected with intake channel  221 . Groove  231  is a linear groove formed on second surface  202  and extending along the X direction. 
         [0051]    As illustrated in  FIG. 5A  and  FIG. 9A , groove  232  is connected with groove  231 . Groove  232  is a groove formed on second surface  202  and extending along the X direction. In plan view, groove  232  has a zigzag shape. In the zigzag shape, protrusions having a substantially triangular shape protruding from the side surface of groove  232  are alternately disposed along the extending direction (the X direction) of groove  232 . The protrusions are disposed such that the tip of each protrusion does not exceed the central line of groove  232  in plan view. Groove  232  has a depth of, for example, 0.5 mm, and groove  232  has a width (W in  FIG. 5 ) of, for example, 0.5 mm. 
         [0052]    As illustrated in  FIG. 5A  and  FIG. 9A , groove  233  is connected with groove  232 . Groove  233  is a linear groove formed on second surface  202  and extending along the X direction. 
         [0053]    As illustrated in  FIG. 5A  and  FIG. 9A , hole  234  opens at an end portion of groove  233 . The opening shape of hole  234  is a rectangular shape. As illustrated in  FIG. 5B  and  FIG. 9B , hole  234  opens at first surface  201 . Grooves  231  and  233  and hole  234  have a width (the length in the Y direction) of, for example, 1 mm. 
         [0054]    As illustrated in  FIG. 6A ,  FIG. 7A  and  FIG. 8A , emitter main body  200  further includes groove  241  formed on first surface  201 , recess  242  formed on first surface  201 , and flow rate control valve  244  disposed on the bottom of recess  242 . 
         [0055]    As illustrated in  FIG. 7A , groove  241  is a linear groove formed on first surface  201  and extending along the Y direction and in plan view, groove  241  has a rectangular shape. Hole  234  opens at one end of groove  241  and recess  242  is connected with the other end of groove  241 . 
         [0056]    As illustrated in  FIG. 7A , recess  242  is a bottomed recess formed on first surface  201 . In plan view, recess  242  has a circular shape. The opening diameter of recess  242  is, for example, 6 mm, and the depth of recess  242  is, for example, 2 mm Recess  251  described later is located on a side opposite to recess  242  in the Z direction. The bottom of recess  242  has a thickness of, for example, 0.2 mm. 
         [0057]    As illustrated in  FIG. 7A  and  FIG. 8B , flow rate control valve  244  has a configuration in which a square pyramid is divided along the sides of the square pyramid with slits in a cross shape into four right angle triangular pyramids. That is, flow rate control valve  244  includes four opening-closing parts  248  and gap  249  formed between each opening-closing parts  248 . 
         [0058]    As illustrated in  FIG. 7A ,  FIG. 8A  and  FIG. 8B , opening-closing part  248  has a right angle triangular pyramid-like shape whose bottom surface has a rectangular equilateral triangular shape. In opening-closing part  248 , the oblique side of the rectangular equilateral triangle of the bottom is a fixed end, the remaining two sides thereof orthogonal to each other are free ends. Opening-closing part  248  is composed of the bottom surface, a side surface having a right triangular-like shape, and a tilted surface having an isosceles triangular (regular triangular) shape. The side surface has a shape with the short side of the bottom surface having a rectangular equilateral triangular-like shape, a side orthogonal to the bottom surface, and an oblique side connecting the other two sides. The distance between bottom sides of opposite two opening-closing parts  248  (the distance between fixed ends of opposite two opening-closing parts  248 , that is, the length of one side of the square pyramid) is, for example, 3.1 mm. In addition, the height of opening-closing part  248  from the bottom of recess  242  is, for example, 1.3 mm. Further, the distance from the apex of opening-closing part  248  to the opening part of recess  242  in the Z direction is 0.2 mm. In addition, the angle of the tilted surface of opening-closing part  248  with respect to the bottom surface of recess  242  is, for example, 45°. 
         [0059]    As illustrated in  FIG. 7A  and  FIG. 9A , gap  249  is formed in a cross shape with two linear slits orthogonal to each other. Gap  249  also opens at recess  251  described later. That is, gap  249  communicates between recess  242  and recess  251 . The width of gap  249  in the XY plane is large at a center portion of the cross shape, and gradually decreases toward end portions thereof from the center portion. The length of the linear slit is, for example, 4.9 mm, and the width of the center portion of the slit (the maximum width of gap  249 ) is, for example, 0.3 mm. In addition, the angle ( 0  in  FIG. 7A ) defined by both end edges from one end to the center portion of the slit is, for example, 5.0 to 15.0°. 
         [0060]    As illustrated in  FIG. 5A  and  FIG. 9A , emitter main body  200  further includes linear protrusion  254  and recesses  251 ,  252  and  253  formed on second surface  202 . 
         [0061]    As illustrated in  FIG. 9A , each of recesses  251 ,  252  and  253  is a recess formed on second surface  202 . In plan view, recess  251  has a circular shape, and gap  249  opens at the bottom of recess  251 . In plan view, recess  252  has a rectangular shape, and linear protrusion  254  is disposed on the bottom of recess  252 . Recess  253  is a recess which connects recess  251  and recess  252 , and is shallower than the recesses. In the Y direction, recess  253  has a length smaller than the length of recess  252 . 
         [0062]    As illustrated in  FIG. 9A , linear protrusion  254  is a slender linear protrusion extending along the Y direction. In plan view, linear protrusion  254  has a rectangular shape, and the length of linear protrusion  254  in the Y direction is smaller than the length of recess  252  in the Y direction and is substantially equal to the length of recess  253  in the Y direction. In the X direction, linear protrusion  254  is disposed at a position near recess  253  but is separated from recess  253 . Thus, as viewed from recess  252  side along the X direction, linear protrusion  254  is disposed at a position where linear protrusion  254  overlaps recess  253 . 
         [0063]    As illustrated in  FIG. 7A  and  FIG. 9A , film  300  is disposed integrally with emitter main body  200  through hinge part  301 . Hinge part  301  is disposed at an edge of first surface  201  of emitter main body  200  in the Y direction. For example, hinge part  301  is a portion having a thickness equal to that of film  300  and a width of 0.5 mm, and is formed integrally with emitter main body  200  and film  300 . 
         [0064]    As illustrated in  FIG. 7A  and  FIG. 9A , film  300  further includes rectangular opening part  302  at a position corresponding to first recess  211  in the state where film  300  covers first surface  201 . For example, the thickness of film  300  may be determined by a computer simulation or an experiment using a trial product or the like on the basis of the deformation amount under a pressure described later, and may be, for example, 0.15 mm. 
         [0065]    Each of emitter main body  200  and film  300  is molded with one material having flexibility such as polypropylene, for example. Examples of the material include resin and rubber, and examples of the resin include polyethylene and silicone. The flexibility of emitter main body  200  and film  300  can be adjusted with use of elastic resin materials, and for example, can be adjusted by the type of an elastic resin, the mixing ratio of an elastic resin material to a hard resin material, and the like. Emitter  120  can be manufactured as an integrally molded member by injection molding, for example. 
       (Operation) 
       [0066]    Film  300  turns about hinge part  301 , and is closely joined on first surface  201  of emitter main body  200 . For example, the joining is performed by welding of a resin material of emitter main body  200  or film  300 , by bonding using an adhesive agent, by pressure bonding of film  300  to emitter main body  200  or the like. 
         [0067]    As illustrated in  FIG. 2A  and  FIG. 4A , when film  300  is joined to first surface  201 , intake channel  221  and recess  212  are sealed with film  300 , and the gap between linear protrusions  214  opens at recess  211  and constitutes a plurality of channels connected with intake channel  221 . Thus, when film  300  is joined to first surface  201 , intake channel  221  and the gap constitute an intake part for receiving the irrigation liquid in tube  110 . 
         [0068]    In addition, when film  300  is joined to first surface  201 , groove  241  and recess  242  are sealed with film  300  as illustrated in  FIG. 4A  and  FIG. 4B . The gap between recess  242  and film  300  serves as a channel for irrigation liquid. The bottom of recess  242  has flexibility of the material of emitter main body  200 . When film  300  is joined to first surface  201 , recess  242 , opening-closing part  248  and gap  249  constitute a flow rate controlling part for controlling the flow rate of the irrigation liquid supplied from a pressure reduction channel described later in accordance with the flow rate of the irrigation liquid supplied from the pressure reduction channel. 
         [0069]    At the bottom of recess  242  which constitutes a part of a channel on the downstream side relative to the pressure reduction channel of irrigation liquid, gap  249  opens in a form of two lines intersecting each other, and is connected with a discharging part described later. Opening-closing parts  248  are disposed with gap  249  therebetween, and are composed of right angle triangular pyramid-like parts uprightly provided in the Z direction in recess  242 . That is, opening-closing part  248  includes free ends facing gap  249  and a linear fixed end connecting the both ends of gap  249 , and, includes a movable part having flexibility and a protrusion protruding from the movable part along the free end toward the channel (recess  242 ) on the downstream side. 
         [0070]    Second surface  202  is joined to the inner wall surface of tube  110 . This joining is performed by welding of the resin material of emitter main body  200  or tube  110 , by bonding using adhesive agent, by pressure bonding of emitter main body  200  to tube  110 , or the like. 
         [0071]    When second surface  202  is joined to the inner wall surface of tube  110 , second surface  202  makes close contact with tube  110 , and intake channel  221  and grooves  231  to  233  are sealed with tube  110 . When grooves  231  to  233  is sealed with tube  110 , grooves  231  to  233  and hole  234  constitute a channel through which the irrigation liquid received from the intake part flows. Among them, groove  232  constitutes as a pressure reduction channel for allowing the irrigation liquid to flow therethrough while reducing the pressure of the irrigation liquid. 
         [0072]    In addition, when second surface  202  is joined to the inner wall surface of tube  110 , recesses  251 ,  252  and  253  are sealed with tube  110 . Discharge port  130  is disposed at a position where tube  110  seals recess  252 . In this manner, when second surface  202  is joined to tube  110 , recess  252  constitutes as a discharge part to which the irrigation liquid having a flow rate controlled by the flow rate controlling part is supplied and which is configured to face discharge port  130 . 
         [0073]    Normally, emitter  120  is joined to the inner periphery wall of tube  110  before discharge port  130  is formed, and thereafter, discharge port  130  is formed at a position corresponding to a discharge part (recess  252 ) of tube  110 . Alternatively, emitter  120  may be joined to the inner wall surface of tube  110  such that emitter  120  is located at the position of preliminarily provided discharge port  130 . 
         [0074]    Next, discharge of irrigation liquid by emitter  120  is described.  FIG. 10A  illustrates part A of  FIG. 4B  in an enlarged manner in the case where the pressure of the irrigation liquid in tube  110  is equal to or higher than a first pressure value and lower than a second pressure value,  FIG. 10B  illustrates part A of  FIG. 4B  in an enlarged manner in the case where the pressure of the irrigation liquid in tube  110  is equal to or higher than the second pressure value and lower than the third pressure value, and  FIG. 10C  illustrates part A of  FIG. 4B  in an enlarged manner in the case where the pressure of the irrigation liquid in tube  110  is equal to or higher than the third pressure value. 
         [0075]    Supply of irrigation liquid to trickle irrigation tube  100  is performed in a range where the pressure of the irrigation liquid do not exceed 0.1 MPa in view of preventing damaging of tube  110  and emitter  120 , for example. When the irrigation liquid is supplied into tube  110 , the irrigation liquid reaches recess  212  covered with film  300  through the gap between recess  211  and linear protrusion  213 , and reaches intake channel  221  through the gap between recess  212  and linear protrusion  214 . Recess  211  and linear protrusion  213 , and recess  212  and linear protrusion  214  constitute a channel for the irrigation liquid and prevent intrusion of floating materials in the irrigation liquid larger than the gap between the linear protrusions. Thus, recesses  211  and  212  and linear protrusions  213  and  214  function as a filter. 
         [0076]    When the pressure of the irrigation liquid in tube  110  is equal to or higher than the first pressure value (for example, 0.005 MPa), flow rate regulation valve  223  is pushed to second surface  202  side, and the slit of flow rate regulation valve  223  is expanded. In this manner, the irrigation liquid reaching intake channel  221  is received into emitter main body  200  from intake channel  221 . Flow rate regulation valve  223  suppresses inflow of the irrigation liquid to emitter main body  200  when the pressure value of the irrigation liquid is lower than the first pressure. Thus, high-pressure supply of the irrigation liquid to tube  110  can be achieved, and therefore the configuration in which emitter  120  has flow rate regulation valve  223  is favorable for forming trickle irrigation tube  100  having a greater length, for example. 
         [0077]    The irrigation liquid received from intake channel  221  is supplied to groove  232  (pressure reduction channel) through groove  231 . The pressure of the irrigation liquid flowing through groove  232  is reduced as a result of pressure loss caused by the shape (zigzag shape) in plan view of groove  232 . In addition, floating materials in the irrigation liquid are entangled in the turbulent flow generated between the protrusions of groove  232  and are retained in groove  232 . In this manner, the floating materials are further removed from the irrigation liquid by pressure reduction channel  230 . 
         [0078]    In addition, since the tip of the protrusion is disposed in such a manner that the tip does not exceed the center line of groove  232  in plan view, a space which is not blocked by the protrusion is formed at the center of groove  232  while the width of the space is small, and thus the irrigation liquid easily flow through groove  232 . Accordingly, in addition to the effect of reducing pressure and the effect of removing the floating material, groove  232  is favorable for allowing irrigation liquid to flow with a greater flow rate. 
         [0079]    The irrigation liquid having passed through groove  232  in which the pressure is reduced and the floating materials are removed is supplied to recess  242  through groove  233 , hole  234 , and groove  241 . As illustrated in  FIG. 10A , the gap between film  300  and recess  242  is filled with the irrigation liquid, and the irrigation liquid reaches recess  251  through gap  249  between opening-closing parts  248 . 
         [0080]    The irrigation liquid having reached recess  251  reaches recess  252  through recess  253  and is then discharged out of tube  110  through discharge port  130  which faces recess  252  and opens at recess  252 . 
         [0081]    It is to be noted that foreign matters such as soil may intrude into recess  252  from discharge port  130 , intrusion of such foreign matters into gap  249  is blocked by linear protrusion  254  disposed in recess  252 . 
         [0082]    As the pressure of the irrigation liquid in tube  110  increases, the flow rate of the irrigation liquid received into emitter main body  200  from intake channel  221  increases, and the discharge rate of the irrigation liquid from discharge port  130  increases. 
         [0083]    When the pressure of the irrigation liquid in tube  110  is equal to or higher than the second pressure value (for example 0.02 MPa), the pressure of the irrigation liquid in recess  242  increases, and opening-closing part  248  is pushed by the irrigation liquid in recess  242  as illustrated in  FIG. 10B . As a result, the bottom side part of the tilted surface of opening-closing part  248  bends (with the bottom side part as a fixed end) and opening-closing parts  248  are brought closer to each other, thus reducing gap  249 . For example, the maximum width of gap  249  is changed to 0.15 mm Consequently, the area of the channel of gap  249  for irrigation liquid and the amount of the irrigation liquid passing through gap  249  are reduced, and thus increase of the discharge rate of the irrigation liquid from discharge port  130  is suppressed. 
         [0084]    When the pressure of the irrigation liquid in tube  110  is equal to or higher than a third pressure value (for example 0.05 MPa), the pressure of the irrigation liquid in recess  242  further increases, and, as illustrated in  FIG. 10C , opening-closing part  248  is further pushed by the irrigation liquid in recess  242 , and tip end portions of opening-closing part  248  make close contact with each other while gap  249  still remain on the fixed end side between opening-closing parts  248 . Thus, gap  249  is reduced to a minimum size. The irrigation liquid in recess  242  is supplied to recess  251  through gap  249  having the minimum size. Consequently, the amount of the irrigation liquid which passes through the flow rate controlling part is restricted to a flow rate which can pass through gap  249  having the minimum size, and the discharge rate of the irrigation liquid from discharge port  130  becomes substantially constant. In this manner, emitter  120  quantitatively discharges the irrigation liquid from tube  110  supplied with the irrigation liquid. 
         [0085]    When the pressure of the irrigation liquid in tube  110  is returned to the second pressure value, opening-closing part  248  is returned to the state illustrated in  FIG. 10B , and when the pressure of the irrigation liquid in tube  110  is returned to the first pressure value, opening-closing part  248  is returned to the state illustrated in  FIG. 10A . In this manner, in emitter  120 , the amount of the irrigation liquid passing through gap  249  is controlled in accordance with the pressure of the irrigation liquid of recess  242 . As described above, the pressure of the irrigation liquid in recess  242  varies in accordance with the pressure of the irrigation liquid in tube  110 . Thus, according to emitter  120 , the discharge rate of the irrigation liquid is controlled in accordance with the pressure of the irrigation liquid in tube  110 . 
       (Effect) 
       [0086]    As described, emitter  120  is an emitter to be disposed on a tube  110  for allowing irrigation liquid to flow therethrough, emitter  120  being configured for quantitatively discharging the irrigation liquid in tube  110  to outside of tube  110 , emitter  120  comprising: the intake part for receiving the irrigation liquid in tube  110 ; the pressure reduction channel for allowing the irrigation liquid received from the intake part to flow therethrough while reducing a pressure of the irrigation liquid; the flow rate controlling part for controlling a flow rate of the irrigation liquid supplied from the pressure reduction channel in accordance with a pressure of the irrigation liquid supplied from the pressure reduction channel; and, the discharging part configured to be supplied with the irrigation liquid which is to be discharged to the outside of tube  110  and has a flow rate controlled by the flow rate controlling part. The flow rate controlling part includes gap  249  opening in a linear shape at recess  242  which is a channel on a downstream side of the pressure reduction channel and communicated with the discharging part, a movable part having flexibility and including a free end facing gap  249  and a fixed end, the fixed end having a straight line shape and connecting both ends of gap  249 , and a protrusion protruding along the free end from the movable part toward recess  242 ; and, when the pressure of the irrigation liquid in the channel is equal to or higher than a predetermined value, the movable part bends and the protrusion reduces a channel area of a channel of the irrigation liquid constituted by gap  249 . Accordingly, emitter  120  controls the discharge rate of the irrigation liquid in accordance with the pressure of the irrigation liquid in the channel on the downstream side which varies depending on the pressure of the irrigation liquid in tube  110 , and thus can stabilize the discharge rate of the irrigation liquid. Further, emitter  120  can be constituted with two injection-molded articles at most, or with one injection-molded article at least. Therefore, emitter  120  can further reduce manufacturing cost in comparison with conventional emitters composed of three parts. 
         [0087]    In addition, emitter  120  is an emitter for quantitatively discharging the irrigation liquid in tube  110  from discharge port  130 , emitter  120  being configured to be joined to an inner wall surface of tube  110  at a position corresponding to the discharge port  130  configured to communicate between inside and outside of tube  110 ; the flow rate controlling part includes: recess  242  for constituting a part of a channel of the irrigation liquid on a downstream side of the pressure reduction channel in emitter  120 , recess  242  opening at a surface of emitter  120  at a position (first surface  201 ) where the surface of emitter  120  is not joined to the inner wall surface; and lid part (film  300 ) configured to seal the opening part and block communication between the channel on the downstream side of the pressure reduction channel and the inside of tube  110 ; recess  242  has a bottom having flexibility; and gap  249  opens at the bottom of recess  242 . This configuration is further effective from the viewpoint of constituting an emitter which can achieve the above-mentioned effects and which is to be disposed inside tube  110 . 
         [0088]    In addition, the protrusion has a shape like a triangular pyramid cut out from a polygonal pyramid along adjacent two sides of the polygonal pyramid which connect a tip end point and a bottom surface of the polygonal pyramid, and one of bottom sides of the triangular pyramid which is common to a bottom side of the polygonal pyramid is the fixed end, and each of remaining two sides is the free end. This configuration makes it possible to constitute the flow rate controlling part which operates in the above-mentioned manner by injection molding with one component, and therefore the configuration is further effective from the standpoint of reducing the manufacturing cost. 
         [0089]    In addition, with the configuration in which the intake part further includes flow rate regulation valve  223  for expanding the channel for the irrigation liquid when the pressure of the irrigation liquid in tube  110  is equal to or higher than a predetermined value, the irrigation liquid can be supplied to tube  110  with a higher pressure, and therefore the configuration is favorable from the standpoint of forming trickle irrigation tube  100  having a greater length. 
         [0090]    In addition, with the configuration in which emitter  120  is molded with one material having flexibility and film  300  is integrally molded as a part of emitter  120 , emitter  120  can be produced as one component by injection molding, and therefore the configuration is further effective from the standpoint of reducing manufacturing cost. 
         [0091]    In addition, since opening-closing part  248  is formed in a right angle triangular pyramid-like shape, the boundary between opening-closing part  248  and the bottom of recess  242  is a base end edge of opening part  248  in the tilted surface, and has a straight line shape. Consequently, since the configuration in which the boundary between opening-closing part  248  and the bottom surface of recess  242  is a straight line is favorable for performing the opening and closing of the protrusion (opening-closing part  248 ) with a smaller force, the configuration is further effective from the viewpoint of precisely setting a predetermined discharge rate of the irrigation liquid in emitter  120 . 
         [0092]    When emitter  120  is joined to the inner wall surface of tube  110 , trickle irrigation tube  100  including tube  110  and emitter  120  disposed to tube  110  is provided. Trickle irrigation tube  100  can discharge irrigation liquid at a desired discharge rate. Accordingly, trickle irrigation tube  100  is favorably used for growing plants. 
       (Modification) 
       [0093]    In trickle irrigation tube  100 , the above-described configurations may be partially changed, or other configurations may be additionally provided as long as the above-described effect is achieved. 
         [0094]    For example, tube  110  may be a seamless tube, or a tube composed of slender sheet(s) joined together along the longitudinal direction. 
         [0095]    In addition, discharge port  130  may be a gap formed at the above-mentioned joining part of the sheets so as to communicate between the inside and the outside of tube  110 , or a pipe sandwiched by the sheets at the joining part. Further, the shape of the discharge port in an axial direction thereof may not be a straight line shape. Examples of the tube having the discharge port include a tube in which a depression having a desired shape and serving as a channel is formed on the surface of the above-mentioned sheet, and a discharge port composed of the channel is formed at the joining part when the sheets are joined together. 
         [0096]    While intake channel  221  of emitter  120  is located at a position on the upstream side in the flow direction of the irrigation liquid in tube  110 , intake channel  221  may be located at a position on the downstream side. In addition, the orientations of a plurality of emitters  120  in one tube  110  may be identical to one another or different from one another. 
         [0097]    In addition, the resin material of emitter main body  200  and the resin material of film  300  may be identical to each other or different from each other. 
         [0098]    While emitter main body  200  is integrally molded by injection molding of resin, emitter main body  200  may be composed of two components of a first surface  201  side component and a second surface  202  side component. In this case, the components on the first surface  201  side are molded integrally with film  300 . With the configuration in which emitter main body  200  is composed of the two components, the pressure reduction channel can be disposed inside emitter main body  200 , for example. Further, the two components may be integrally molded through a hinge part. 
         [0099]    In addition, the channel connecting intake channel  221  and recess  242  which include the pressure reduction channel may be composed of a groove on first surface  201  covered with film  300  in emitter main body  200 . 
         [0100]    In addition, second surface  202  may be a curved surface extending along the inner wall of tube  110  (for example, a surface defined by the arc whose arc radius is the internal diameter of tube  110  in the YZ plane). 
         [0101]    Further, since it suffices to appropriately dispose flow rate regulation valve  223  in accordance with the pressure of the irrigation liquid supplied to tube  110 , emitter  120  may not be provided with flow rate regulation valve  223 . 
         [0102]    While emitter  120  preferably include a pressure reduction channel having the above-mentioned shape from the viewpoint of ensuring a predetermined discharge rate, emitter  120  may not be provided with the pressure reduction channel. For example, while opening-closing part  248  operates with the pressure of the irrigation liquid in recess  242 , the pressure reduction channel may not have the above-described shape (for example, may be a simple linear channel) as long as the channel from the intake part to the flow rate regulation part is a channel which generates the above-mentioned pressure for achieving a desired operation of opening-closing part  248 . 
         [0103]    In addition, flow rate control valve  244  may have polygonal shapes other than a square in plan view. For example, flow rate control valve  244  may have a triangular shape, or a hexagonal shape in plan view. Flow rate control valve  244  having a plan shape with a small number of angles is favorable for facilitating the contact between opening-closing parts  248  which operate with a high pressure, and flow rate control valve  244  having a plan shape with a large number of angles is favorable for increasing the difference of the flow rate of the irrigation liquid by the operation of opening-closing part  248 . 
         [0104]    In addition, opening-closing part  248  may not be a triangular pyramid-like member as long as opening-closing part  248  operates with the pressure of the irrigation liquid in recess  242  in the above-mentioned manner. For example, as illustrated in  FIG. 21A , opening-closing part  248  may include hollow part  255  which opens at the bottom surface of the triangular pyramid-like member (to recess  251  side), or, as illustrated in  FIG. 21B , may include a hollow part  245  which opens at the tilted surface of the triangular pyramid-like member (to recess  242  side). The configuration in which opening-closing part  248  is provided with the above-mentioned hollow part is favorable for constituting opening-closing part  248  with a molded article having a constant thickness, and therefore the configuration is further effective from the viewpoint of increasing the productivity of emitter  120  by injection molding. 
         [0105]    In addition, one or a plurality of opening-closing parts  248  may be provided. For example, it is possible to adopt a configuration in which only a part of opening-closing parts  248  having a structure of a polygonal pyramid body divided with gap  249  is movable and the remaining parts are integrally provided such that gap  249  is not formed. Alternatively, it is possible to adopt a configuration in which only a part of opening-closing parts  248  is movable, and the remaining parts are fixed to each other with gap  249  therebetween. The opening and closing of opening-closing part  248  can be further readily designed with the configuration in which the number of movable opening-closing parts  248  is small, and the configuration in which the number of movable opening-closing part  248  is large is favorable for increasing the difference of the flow rate of the irrigation liquid by the operation of opening-closing part  248 . It is to be noted that, when only one opening-closing part  248  is movable, the opening shape of gap  249  may be a V-shape composed of two linear slits intersecting each other. In addition, gap  249  may not be linear. In this manner, the opening shape of gap  249  may be a folded shape or a curved shape which sections opening-closing part  248 . 
       Embodiment 2 
       [0106]    Now Embodiment 2 of the present invention is described. 
       (Configuration) 
       [0107]      FIG. 11  is a schematic sectional view of trickle irrigation tube  500  according to Embodiment 2 of the present invention. Trickle irrigation tube  500  is composed of tube  110  and emitter  320 . The configuration of tube  110  is identical to that of the above-described Embodiment 1. The configuration of tube  110  is identical to that of the above-described Embodiment 1. 
         [0108]      FIG. 12A  is a perspective view of emitter  320  in  FIG. 1  as viewed from tube  110  side, and  FIG. 12B  is a perspective view of emitter  320  in  FIG. 1  as viewed from a side opposite to tube  110 .  FIG. 13A  is a plan view of emitter  320 ,  FIG. 13B  is a front view of emitter  320 ,  FIG. 13C  is a bottom view of emitter  320 , and  FIG. 13D  is a side view of emitter  320 . In addition,  FIG. 14A  is a sectional view of emitter  320  taken along line A-A of  FIG. 13A , and  FIG. 14B  is a sectional view of emitter  320  taken along line B-B of  FIG. 13A . 
         [0109]    Emitter  320  includes first cylindrical part  410 , flange part  420  connected with first cylindrical part  410 , and second cylindrical part  430  connected with flange part  420  on a side opposite to first cylindrical part  410  side. Flange part  420  is composed of a combination of first plate part  450  and second plate part  460 . It is to be noted that the Z direction is a direction along the axis of first cylindrical part  410 , and includes the direction along which emitter  320  is inserted to tube  110 . The X direction is one direction orthogonal to the Z direction, and the Y direction is a direction orthogonal to both of the Z direction and the X direction. 
         [0110]    As illustrated in  FIG. 12A , first cylindrical part  410  is a cylindrical member uprightly provided on the surface of first plate part  450 . As illustrated in  FIG. 13A  and  FIG. 13B , first cylindrical part  410  is disposed at a center portion of flange part  420  in plan view. 
         [0111]    As illustrated in  FIG. 14A , barb  411  is formed at a tip end portion of first cylindrical part  410 . Barb  411  is composed of large diameter part  412  which expands from the outer peripheral surface of first cylindrical part  410  along XY plane, and tapered surface  413  whose outer diameter gradually decreases from large diameter part  412  toward the tip end of first cylindrical part  410 . For example, first cylindrical part  410  has an internal diameter of 2 mm, large diameter part  412  has an outer diameter of 3.2 mm, an end of tapered surface  413  has an outer diameter of 2.6 mm, and first cylindrical part  410  has a height from the surface of flange part  420  of 5 mm. 
         [0112]    As viewed along the Z direction (as the shape in plan view), flange part  420  has a circular shape. For example, flange part  420  has a thickness of 3 mm, and flange part  420  has an outer diameter of 16 mm. 
         [0113]    As illustrated in  FIG. 12B , second cylindrical part  430  is a cylindrical member uprightly provided on the second surface of second plate part  460 . As illustrated in  FIG. 13B  and  FIG. 13C , second cylindrical part  430  is disposed at a position shifted from the center of flange part  420  in the X direction in plan view on a side opposite to first cylindrical part  410 . As illustrated in  FIG. 14A , second cylindrical part  430  includes an opening of recess  463  described later on the second surface. That is, second cylindrical part  430  is communicated with recess  463 . The internal diameter of second cylindrical part  430  is equal to the diameter of recess  463 . 
         [0114]    As illustrated in  FIG. 14A  and  FIG. 14B , barb  431  is formed at an end portion of second cylindrical part  430  as with first cylindrical part  410 . Barb  431  is composed of large diameter part  432  which expands from the outer peripheral surface of second cylindrical part  430  along the XY plane, and tapered surface  433  whose outer diameter gradually decreases from large diameter part  432  toward an end of second cylindrical part  430 . For example, second cylindrical part  430  has an internal diameter of 3 mm, large diameter part  432  has an outer diameter of 5 mm, the end of tapered surface  433  has an outer diameter of 4 mm, and second cylindrical part  430  has a height from the second surface of second plate part  460  of 12 mm. 
         [0115]      FIG. 15A  is a plan view of an integrally molded article (hereinafter also referred to as “first member”) of first cylindrical part  410  and first plate part  450 ,  FIG. 15B  is a front view of the first member, and  FIG. 15C  is a bottom view of the first member. In addition,  FIG. 16A  is a sectional view of the first component taken along line A-A of  FIG. 15A , and  FIG. 16B  is a sectional view of the first component taken along line B-B of  FIG. 15A . 
         [0116]    As illustrated in  FIG. 15C ,  FIG. 16A  and  FIG. 16B , first plate part  450  includes hole  451  opening at the surface, and recesses  453  and  454 , grooves  455  and  456  and linear protrusion  457  formed on the bottom surface. First plate part  450  further includes flow rate regulation valve  458  which covers hole  451  at the boundary part between hole  451  and recess  453 . 
         [0117]    As illustrated in  FIG. 14B  and  FIG. 16B , hole  451  opens at a center portion of the surface of first plate part  450 , and opens at recess  453  described later. In addition, the opening of hole  451  on the surface of first plate part  450  is included in first cylindrical part  410 . That is, hole  451  communicates between first cylindrical part  410  and recess  453 . In plan view, hole  451  has a circular shape as illustrated in  FIG. 13A . The diameter of hole  451  is equal to the internal diameter of first cylindrical part  410 . 
         [0118]    As illustrated in  FIG. 16A  and  FIG. 16B , recess  453  is a recess formed at a center portion of the bottom surface of first plate part  450 . In plan view, recess  453  has a circular shape as illustrated in  FIG. 15C . The diameter of recess  453  is slightly greater than the internal diameter of first cylindrical part  410 . Recess  453  has a depth from the bottom surface of first plate part  450  of, for example, 0.5 mm. 
         [0119]    As illustrated in  FIG. 15C , groove  455  is a groove formed on the bottom surface of first plate part  450  and connected with recess  453 . As illustrated in  FIG. 15C , groove  455  extends along the radial direction on the bottom surface of first plate part  450  from recess  453  to a peripheral portion of the bottom surface of first plate part  450 . In plan view, groove  455  has a zigzag shape similar to that of the groove  232 , and groove  455  has a width (in  FIG. 15C  W) of, for example, 0.45 mm. 
         [0120]    As illustrated in  FIG. 15C , recess  454  is a recess formed independently from recess  453  on the bottom surface of first plate part  450  at a position adjacent to recess  453  in the X direction. In plan view, recess  454  has a rectangular shape. Recess  454  has a depth from the bottom surface of first plate part  450  of, for example, 0.2 mm. 
         [0121]    As illustrated in  FIG. 15C , groove  456  is a groove formed on the bottom surface of first plate part  450 , and connects groove  455  and recess  454 . In plan view, groove  456  has an L shape, and groove  456  is connected with groove  455  at an end of the short side of the L-shape and with recess  454  at an end portion of the long side of the L-shape. 
         [0122]    As illustrated in  FIG. 15C , linear protrusion  457  is disposed at a peripheral portion of the bottom surface of first plate part  450 , and as illustrated in  FIG. 16 , linear protrusion  457  protrudes from the bottom surface of first plate part  450 . In plan view, linear protrusion  457  has a ring shape as illustrated in  FIG. 15C . Linear protrusion  457  has a height from the bottom surface of first plate part  450  of, for example, 1 mm. 
         [0123]    As with the above-described flow rate regulation valve  223 , flow rate regulation valve  458  is composed of four opening-closing parts. As illustrated in  FIG. 16A  and  FIG. 16B , the opening-closing part has a form similar to the form in which a substantially hemisphere thin dome covering the opening of recess  453  side of hole  451  and protruding toward recess  453  is divided with slits in a cross shape. The slit has a width of, for example, 0 mm, and the opening-closing part has a thickness of, for example, 0.2 mm. 
         [0124]      FIG. 17A  is a plan view of an integrally formed member (hereinafter also referred to as “second member”) of second cylindrical part  430  and second plate part  460 ,  FIG. 17B  is a front view of the second member,  FIG. 17C  is a bottom view of the second member, and  FIG. 17D  is a side view of the second member. In addition,  FIG. 18  is a sectional view of the second member taken along line A-A of  FIG. 17A . 
         [0125]    As illustrated in  FIG. 18 , second plate part  460  includes recess  461  and linear recess  462  formed on one surface of (first surface) and recess  463  formed on the other surface (second surface). Recess  461  includes flow rate control valve  464  disposed on the bottom thereof. 
         [0126]    As illustrated in  FIG. 18 , recess  461  is a bottomed recess which opens at the first surface of second plate part  460 . In plan view, recess  461  has a circular shape. Recess  463  described later is disposed on a side opposite to recess  461  with second plate part  460  therebetween as illustrated in  FIG. 18  and  FIG. 17A . The bottom of recess  461  has a thickness of, for example, 0.2 mm. 
         [0127]    As illustrated in  FIG. 17A  and  FIG. 18 , flow rate control valve  464  has a configuration in which a square pyramid is divided along the sides of the square pyramid with slits in a cross shape into four right angle triangular pyramids. That is, flow rate control valve  464  includes four opening-closing parts  468  and gap  469  formed between each opening-closing parts  248 . 
         [0128]    As illustrated in  FIG. 17A , opening-closing part  468  has a right angle triangular pyramid-like shape whose bottom surface has a rectangular equilateral triangular shape. As illustrated in  FIG. 18 , in opening-closing part  468 , the oblique side of the rectangular equilateral triangle of the bottom is a fixed end, and the remaining two sides thereof orthogonal to each other are free ends. Opening-closing part  468  is composed of the bottom surface, a side surface having a right triangular-like shape, and a tilted surface having an isosceles triangular (regular triangular) shape. The side surface has a shape with the short side of the bottom surface having a rectangular equilateral triangular-like shape, a side orthogonal to the bottom surface, and an oblique side connecting the other two sides. The distance between bottom sides of opposite two opening-closing parts  468  (the distance between fixed ends of opposite two opening-closing parts  468 , that is, the length of one side of the square pyramid) is, for example, 2.0 mm. In addition, the height of opening-closing part  468  from the bottom of recess  461  is, for example, 0.8 mm. Further, the distance from the apex of opening-closing part  468  to the opening part of recess  461  in the Z direction is 0.2 mm. In addition, the angle of the tilted surface of opening-closing part  468  with respect to the bottom surface of recess  461  is, for example, 45°. 
         [0129]    As illustrated in  FIG. 17A , gap  469  is formed in a cross shape with two linear slits orthogonal to each other. Gap  469  also opens at recess  463  described later. That is, gap  469  communicates between recess  463  and recess  251 . The width of gap  469  in the XY plane is large at a center portion of the cross shape, and gradually decreases toward end portions thereof from the center portion. The width of the center portion of the slit (the maximum width of gap  469 ) is, for example, 0.3 mm. In addition, the angle ( 0  in  FIG. 17C ) defined by both end edges from one end to the center portion of the slit is, for example, 5.0 to 15.0°. 
         [0130]    As illustrated in  FIG. 17A , linear recess  462  is disposed at the peripheral portion of the first surface, and is depressed from the second surface as illustrated in  FIG. 17B  and  FIG. 17D . In plan view, linear recess  462  has a ring shape as illustrated in  FIG. 17A . Linear recess  462  has a depth from the second surface of, for example, 1 mm. 
         [0131]    As illustrated in  FIG. 18 , recess  463  is disposed at a position where recess  463  overlaps recess  461  in the Z direction in the second surface. As is obvious from  FIG. 17C  and  FIG. 18 , recess  463  has a circular shape in plan view. Gap  469  opens at the bottom surface of recess  463 . 
         [0132]    As with emitter main body  200  of Embodiment 1, each of the first component and the second component is integrally molded by injection molding using one resin material having flexibility (for example, polypropylene). Examples of the material of the first component and the second component include resin and rubber, and examples of the resin include polyethylene and silicone. The flexibility of the material is properly adjusted by the type of the resin material, mixture of two or more resin materials or the like in accordance with the flexibility required for flow rate control valve  464  (opening-closing part  468 ). 
       (Operation) 
       [0133]    The first member and the second member are combined with each other by fitting linear protrusion  457  of first plate part  450  with linear recess  462  of second plate part  460 , and thus emitter  320  is constituted as illustrated in  FIG. 12A  and  FIG. 12B . The bottom surface of first plate part  450  and the first surface of the second plate part may be further bonded by welding of a resin material, by bonding using an adhesive agent, by pressure bonding of one of them to the other or the like. 
         [0134]    As illustrated in  FIG. 14A  and  FIG. 14B , when the first member and the second member are combined with each other, grooves  455  and  456  illustrated in  FIG. 15C  are sealed with the surface of second plate part  460 , and thus the channel for irrigation liquid is constituted. In addition, the intake part for receiving the irrigation liquid in tube  110  is composed with first cylindrical part  410 , hole  451  and recess  453 . Groove  455  constitutes as the pressure reduction channel for allowing the irrigation liquid received from the intake part to flow therethrough while reducing the pressure of the irrigation liquid. 
         [0135]    In addition, recess  454  illustrated in  FIG. 15C  and recess  461  illustrated in  FIG. 17A  constitute a part of a channel on the downstream side relative to the pressure reduction channel of the irrigation liquid when the first member and the second member are combined with each other. In addition, opening-closing part  468  and gap  469  constitute a flow rate controlling part for controlling the flow rate of the irrigation liquid supplied from the pressure reduction channel in accordance with the pressure of the irrigation liquid supplied from the pressure reduction channel. 
         [0136]    In the flow rate controlling part, the bottom of recess  461  has flexibility of the material of the second member. At the bottom of recess  461  which constitutes a part of a channel on the downstream side relative to the pressure reduction channel of irrigation liquid, gap  469  opens in a form of two lines intersecting each other, and is connected with a discharging part described later. Opening-closing parts  468  are disposed with gap  469  therebetween, and are composed of right angle triangular pyramid-like parts uprightly provided in the Z direction in recess  461 . That is, opening-closing part  468  includes free ends facing gap  469  and a linear fixed end connecting the both ends of gap  469 , and, includes a movable part having flexibility and a protrusion protruding from the movable part along the free end toward the channel (recess  461 ) on the downstream side. 
         [0137]    It is to be noted that second cylindrical part  430  is communicated with recess  461  and constitutes as the discharge part which is supplied with irrigation liquid which is to be discharged out of tube  110  and has a flow rate controlled by the flow rate controlling part. 
         [0138]    As illustrated in  FIG. 11 , emitter  320  is attached to tube  110  by inserting first cylindrical part  410  to the pipe wall of tube  110 . Attaching of emitter  320  may be performed by penetrating the pipe wall of tube  110  with first cylindrical part  410 , or by inserting first cylindrical part  410  to an opening part for insertion which is preliminarily formed on the pipe wall of tube  110 . The former is favorable for arbitrarily disposing emitter  320  on tube  110 , and the latter is favorable for preventing leakage of irrigation liquid from tube  110 . Since first cylindrical part  410  includes a barb at an end portion thereof, dropping of emitter  320  from tube  110  is prevented. 
         [0139]    It is to be noted that second cylindrical part  430  of emitter  320  includes barb  431  as illustrated in  FIG. 14A  and  FIG. 14B . Accordingly, barb  431  can be inserted to a mulching film covering the soil, or barb  431  can be inserted to a fibrous cultivation bed. Insertion of barb  431  to the cultivation bed is favorable for specifying the position of dropping of irrigation liquid to the cultivation bed, and for fixing trickle irrigation tube  500  on the cultivation bed. 
         [0140]    Next, discharge of irrigation liquid by emitter  320  is described.  FIG. 19A  illustrates part A of  FIG. 14A  in an enlarged manner in the case where the pressure of the irrigation liquid in tube  110  is equal to or higher than a first pressure value and lower than a second pressure value.  FIG. 19B  illustrates part A of  FIG. 14A  in an enlarged manner in the case where the pressure of the irrigation liquid in tube  110  is equal to or higher than the second pressure value and lower than the third pressure value.  FIG. 19C  illustrates part A of  FIG. 14A  in an enlarged manner in the case where the pressure of the irrigation liquid in tube  110  is equal to or higher than the third pressure value. 
         [0141]    Supply of irrigation liquid to trickle irrigation tube  500  is performed in a range where the pressure of the irrigation liquid does not exceed 0.1 MPa for example in view of preventing the damaging of tube  110  and emitter  320 . When the irrigation liquid is supplied into tube  110 , the irrigation liquid reaches flow rate regulation valve  458  through first cylindrical part  410 . 
         [0142]    When the pressure of the irrigation liquid in tube  110  is equal to or higher than a first pressure value (for example 0.005 MPa), flow rate regulation valve  458  is pushed toward second plate part  460 , and the slit of flow rate regulation valve  458  expands. In this manner, the irrigation liquid flows into flange part  420 . Flow rate regulation valve  458  suppresses inflow of irrigation liquid into flange part  420  in the case where the pressure of the irrigation liquid is lower tm the first pressure value. The pressure of the irrigation liquid is lower tm the first pressure value. Thus, irrigation liquid can be supplied to the tube  110  with high pressure, and therefore the configuration in which emitter  320  includes flow rate regulation valve  458  is favorable for forming trickle irrigation tube  500  having a greater length, for example. 
         [0143]    The irrigation liquid having passed through flow rate regulation valve  458  is supplied to groove  455  (pressure reduction channel). The pressure of the irrigation liquid flowing through groove  455  is reduced as a result of pressure loss caused by the shape (zigzag shape) in plan view of groove  455 . In addition, floating materials in the irrigation liquid are entangled in the turbulent flow generated between the protrusions of groove  455  and are retained in groove  455 . In this manner, the floating materials are further removed from the irrigation liquid by groove  455 . 
         [0144]    In addition, since the tip of the protrusion is disposed such that the tip of the protrusion does not exceed the center line of groove  455  in plan view, a space which is not blocked by the protrusion is formed at the center of groove  455  while the width of the space is small, and thus the irrigation liquid easily flow through groove  455 . Accordingly, in addition to the effect of reducing pressure and the effect of removing the floating material, groove  455  is favorable for allowing irrigation liquid to flow with a greater flow rate. 
         [0145]    The irrigation liquid having passed through groove  455  in which the pressure is reduced and the floating materials are removed is supplied into recess  461  through groove  456 . Recesses  454  and  461  are filled with the irrigation liquid, and the irrigation liquid passes through gap  469  ( FIG. 19A ). 
         [0146]    The irrigation liquid having passed through gap  469  reaches second cylindrical part  430  through recess  463 , and is discharged out of tube  110  through second cylindrical part  430 . 
         [0147]    As the pressure of the irrigation liquid in tube  110  increases, the flow rate of the irrigation liquid received into emitter  320  from first cylindrical part  410  increases, and consequently the discharge rate of the irrigation liquid from second cylindrical part  430  increases. 
         [0148]    When the pressure of the irrigation liquid in tube  110  is equal to or higher than the second pressure value (for example 0.02 MPa), the pressure of the irrigation liquid in recess  461  increases, and opening-closing part  468  is pushed by the irrigation liquid in recess  461  as illustrated in  FIG. 19B . As a result, the bottom side part of the tilted surface of opening-closing part  468  bends (with the bottom side part as a fixed end) and opening-closing parts  468  are brought closer to each other, thus reducing gap  469 . For example, the maximum width of gap  469  is changed to 0.15 mm Consequently, the area of the channel of gap  469  for irrigation liquid and the amount of the irrigation liquid passing through gap  469  are reduced, and thus increase of the discharge rate of the irrigation liquid from second cylindrical part  430  is suppressed. 
         [0149]    When the pressure of the irrigation liquid in tube  110  is equal to or higher than a third pressure value (for example 0.05 MPa), the pressure of the irrigation liquid in recess  461  further increases, and, as illustrated in  FIG. 19C , opening-closing part  468  is further pushed by the irrigation liquid in recess  461 , and tip end portions of opening-closing part  468  make close contact with each other while gap  469  on the fixed ends of opening-closing parts  468  still remain. Thus, gap  469  is reduced to a minimum size. The irrigation liquid in recess  461  is supplied to recess  463  through gap  469  having the minimum size. Consequently, the amount of the irrigation liquid which passes through the flow rate controlling part is restricted to a flow rate which can pass through gap  469  having the minimum size, and the discharge rate of the irrigation liquid from second cylindrical part  430  becomes substantially constant. In this manner, emitter  320  quantitatively discharges the irrigation liquid from tube  110  supplied with the irrigation liquid. 
         [0150]    When the pressure of the irrigation liquid in tube  110  is returned to the second pressure value, opening-closing part  468  is returned to the state illustrated in  FIG. 19B , and when the pressure of the irrigation liquid in tube  110  is returned to the first pressure value, opening-closing part  468  is returned to the state illustrated in  FIG. 19A . In this manner, in emitter  320 , the amount of the irrigation liquid passing through gap  469  is controlled in accordance with the pressure of the irrigation liquid of recess  461 . As described above, the pressure of the irrigation liquid in recess  461  varies in accordance with the pressure of the irrigation liquid in tube  110 . Thus, according to emitter  320 , the discharge rate of the irrigation liquid is controlled in accordance with the pressure of the irrigation liquid in tube  110 . 
       (Effect) 
       [0151]    As described, emitter  320  is an emitter to be disposed on a tube  110  for allowing irrigation liquid to flow therethrough, emitter  320  being configured for quantitatively discharging the irrigation liquid in tube  110  to outside of tube  110 , emitter  320  comprising: the intake part for receiving the irrigation liquid in tube  110 ; the pressure reduction channel for allowing the irrigation liquid received from the intake part to flow therethrough while reducing a pressure of the irrigation liquid; the flow rate controlling part for controlling a flow rate of the irrigation liquid supplied from the pressure reduction channel in accordance with a pressure of the irrigation liquid supplied from the pressure reduction channel; the discharging part configured to be supplied with the irrigation liquid which is to be discharged to the outside of tube  110  and has a flow rate controlled by the flow rate controlling part. The flow rate controlling part includes gap  469  opening in a linear shape at recess  461  which is a channel on a downstream side of the pressure reduction channel and connected with the discharging part, a movable part having flexibility and including a free end facing gap  469  and a fixed end, the fixed end having a straight line shape and connecting both ends of gap  469 , and a protrusion protruding along the free end from the movable part toward recess  461 ; and, when the pressure of the irrigation liquid in the channel is equal to or higher than a predetermined value, the movable part bends and the protrusion reduces a channel area of a channel of the irrigation liquid constituted by gap  469 . Accordingly, emitter  320  controls the discharge rate of the irrigation liquid in accordance with the pressure of the irrigation liquid in the channel on the downstream side which varies depending on the pressure of the irrigation liquid in tube  110 , and thus can stabilize the discharge rate of the irrigation liquid. Further, emitter  320  can be constituted with two injection-molded articles. Therefore, emitter  320  can further reduce manufacturing cost in comparison with conventional emitters composed of three parts. 
         [0152]    In addition, emitter  320  includes: first cylindrical part  410  for constituting the intake part; flange part  420  for forming the pressure reduction channel and the flow rate controlling part, flange part  420  being connected with one end of first cylindrical part  410  and extending outward from the one end of first cylindrical part  410 ; and second cylindrical part  430  for constituting the discharge part, second cylindrical part  430  being connected on a side opposite to first cylindrical part  410  of flange part  420 ; emitter  320  is disposed on tube  110  by inserting first cylindrical part  410  into tube  110  from outside of tube  110 ; flange part  420  is composed of a combination of first plate part  450  connected with first cylindrical part  410  and second plate part  460  connected with second cylindrical part  430 ; first plate part  450  includes the pressure reduction channel; second plate part  460  includes recess  461  opening at a channel on a downstream side of the pressure reduction channel; recess  461  has a bottom having flexibility; and gap  469  opens at the bottom of recess  461 . This configuration is further effective from the viewpoint of constituting emitter which can achieve the above-mentioned effect and is to be disposed on the outside of tube  110 . 
         [0153]    In addition, the protrusion has a shape like a triangular pyramid cut out from a polygonal pyramid along adjacent two sides of the polygonal pyramid which connect a tip end point and a bottom surface of the polygonal pyramid, and one of bottom sides of the triangular pyramid which is common to a bottom side of the polygonal pyramid is the fixed end, and each of remaining two sides is the free end. This configuration makes it possible to constitute the flow rate controlling part which operates in the above-mentioned manner by injection molding with one component, and is further effective from the viewpoint of reducing manufacturing cost. 
         [0154]    In addition, with the configuration in which the intake part further includes flow rate regulation valve  458  for expanding the channel for the irrigation liquid when the pressure of the irrigation liquid in tube  110  is equal to or higher than a predetermined value, the irrigation liquid can be supplied to tube  110  with a higher pressure, and therefore the configuration is favorable from the standpoint of forming trickle irrigation tube  500  having a greater length. 
         [0155]    In addition, with the configuration in which emitter  320  is molded with one material having flexibility, emitter  320  can be produced as one component by injection molding, and therefore the configuration is further effective from the standpoint of reducing manufacturing cost. 
         [0156]    In addition, since opening-closing part  468  is formed in a right angle triangular pyramid-like shape, the boundary between opening-closing part  468  and the bottom of recess  461  is a base end edge of opening part  468  in the tilted surface, and has a straight line shape. Consequently, since the configuration in which the boundary between opening-closing part  468  and the bottom surface of recess  461  is a straight line is favorable for performing the opening and closing of the protrusion (opening-closing part  468 ) with a smaller force, the configuration is further effective from the viewpoint of precisely setting a predetermined discharge rate of the irrigation liquid in emitter  320 . 
         [0157]    When first cylindrical part  410  is inserted into tube  110  from the external side of tube  110 , trickle irrigation tube  500  including tube  110  and emitter  320  disposed to tube  110  is provided. Trickle irrigation tube  500  can discharge irrigation liquid at a desired discharge rate. Accordingly, trickle irrigation tube  500  is favorably used for growing plants. 
       (Modification) 
       [0158]    In trickle irrigation tube  500 , the above-described configurations may be partially changed, or other configurations may be additionally provided as long as the above-described effect is achieved. 
         [0159]    For example, second cylindrical part  430  may not have barb  431  as illustrated in  FIG. 20A , and may be an opening part which opens at the second surface of second plate part  460  as illustrated in  FIG. 20B . 
         [0160]    In addition, tube  110  may be a seamless tube, a tube composed of slender sheet(s) joined together along the longitudinal direction, or a tube having a gap formed at the above-mentioned joining part of the sheets so as to communicate between the inside and the outside of tube  110 , or a pipe sandwiched by the sheets at the joining part. 
         [0161]    In addition, the first component and the second component may be integrally formed so as to be turnable about a hinge part integrally formed with the first component and the second component. In this case, the number of components of emitter  320  can be further reduced, that is, emitter  320  can be produced with one component. 
         [0162]    While emitter  320  preferably include a pressure reduction channel having the above-mentioned shape from the viewpoint of ensuring a predetermined discharge rate, emitter  320  may not be provided with the pressure reduction channel. For example, while opening-closing part  468  operates with the pressure of the irrigation liquid in recess  461 , the pressure reduction channel may not have the above-described shape (for example, may be a simple linear channel) as long as the channel from the intake part to the flow rate regulation part is a channel which generates the above-mentioned pressure for achieving a desired operation of opening-closing part  468 . 
         [0163]    In addition, flow rate control valve  464  may have polygonal shapes other than a square in plan view. For example, flow rate control valve  464  may have a triangular shape, or a hexagonal shape in plan view. Flow rate control valve  464  having a plan shape with a small number of angles is favorable for facilitating the contact between opening-closing parts  468  which operate with a high pressure, and flow rate control valve  464  having a plan shape with a large number of angles is favorable for increasing the difference of the flow rate of the irrigation liquid by the operation of opening-closing part  468 . 
         [0164]    In addition, as with opening-closing part  248  in Embodiment 1, opening-closing part  468  may include a hollow part illustrated in  FIG. 21A  and  FIG. 21B . The configuration in which opening-closing part  468  is provided with the above-mentioned hollow part is favorable for constituting opening-closing part  468  with a molded article having a constant thickness, and therefore the configuration is further effective from the viewpoint of increasing the productivity of emitter  320  by injection molding. 
         [0165]    In addition, one or a plurality of opening-closing parts  468  may be provided. For example, it is possible to adopt a configuration in which only a part of opening-closing parts  468  having a structure of a polygonal pyramid body divided with gap  469  is movable and the remaining parts are integrally provided such that gap  469  is not formed. Alternatively, it is possible to adopt a configuration in which only a part of opening-closing parts  468  is movable, and the remaining parts are fixed to each other with gap  469  therebetween. The opening and closing of opening-closing part  468  can be further readily designed with the configuration in which the number of movable opening-closing parts  468  is small, and the configuration in which the number of movable opening-closing part  468  is large is favorable for increasing the difference of the flow rate of the irrigation liquid by the operation of opening-closing part  468 . It is to be noted that, when only one opening-closing part  468  is movable, the opening shape of gap  469  may be a V-shape composed of two linear slits intersecting each other. In addition, gap  469  may not be linear. In this manner, the opening shape of gap  469  may be a folded shape or a curved shape which sections opening-closing part  468 . 
         [0166]    This application is entitled to and claims the benefit of Japanese Patent Application No. 2014-003264 filed on Jan. 10, 2014, the disclosure each of which including the specification, drawings and abstract is incorporated herein by reference in its entirety. 
       INDUSTRIAL APPLICABILITY 
       [0167]    According to the present invention, an emitter which can discharge liquid with an appropriate speed by the pressure of the liquid to be discharged can be easily provided. Accordingly, popularization of the above-mentioned emitter in technical fields of trickle irrigations, endurance tests and the like where long-term discharging is required, and further development of the technical fields can be expected. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           100 ,  500  Trickle irrigation tube 
           110  Tube 
           120 ,  320  Emitter 
           130  Discharge port 
           200  Emitter main body 
           201  First surface 
           202  Second surface 
           211 ,  212 ,  242 ,  251 ,  252 ,  253 ,  453 ,  454 ,  461 ,  463  Recess 
           213 ,  214 ,  254 ,  457  Linear protrusion 
           221  Intake channel 
           223 ,  458  Flow rate regulation valve 
           231 ,  232 ,  233 ,  241 ,  455 ,  456  Groove 
           234 ,  451  Hole 
           244 ,  464  Flow rate control valve 
           245 ,  255  Hollow part 
           248 ,  468  Opening-closing part 
           249 ,  469  Gap 
           300  Film 
           301  Hinge part 
           302  Opening part 
           410  First cylindrical part 
           411 , 431  Barb 
           412 ,  432  Large diameter part 
           413 ,  433  Tapered part 
           420  Flange part 
           430  Second cylindrical part 
           450  First plate part 
           460  Second plate part 
           462  Linear recess