Patent Publication Number: US-11389813-B2

Title: Trigger type liquid ejector

Description:
TECHNICAL FIELD 
     The present invention relates to a trigger type liquid ejector. 
     Priority is claimed on Japanese Patent Application No. 2018-105653, filed May 31, 2018, and Japanese Patent Application No. 2018-105654, filed May 31, 2018, the contents of which are incorporated herein by reference. 
     BACKGROUND ART 
     A trigger type liquid ejector having configurations disclosed in the following Patent Document 1 is known. The trigger type liquid ejector includes an ejector body mounted on a container body in which liquid is accommodated, and a nozzle disposed in front of the ejector body and in which an ejection hole configured to eject the liquid is formed. 
     The ejector body includes a vertical supply pipe, an ejection barrel, and a trigger mechanism, the vertical supply pipe extends in an upward/downward direction and is configured to suction the liquid in the container body, the ejection barrel is disposed in front of the vertical supply pipe and is configured to guide the liquid in the vertical supply pipe to the ejection hole, and the trigger mechanism has a trigger disposed in front of the vertical supply pipe to be movable rearward in a state where the trigger is biased forward. 
     The above-described trigger mechanism includes a cylinder and a piston, the cylinder communicates with the inside of the ejection barrel through the vertical supply pipe, and the piston is linked to the trigger and is configured to slide inside the cylinder in a forward/rearward direction according to forward and rearward movement of the trigger. The inside of the cylinder inside is pressurized and depressurized according to forward and rearward movement of the piston. 
     In the above-described trigger type liquid ejector, as the trigger is pulled rearward, the piston is moved rearward while being guided by a piston guide formed in the cylinder. Thereby, the inside of the cylinder is pressurized, and liquid in the cylinder passes through the vertical supply pipe and the ejection barrel and is ejected from the ejection hole. 
     In the above-described trigger type liquid ejector, for example when the amount of the liquid remained in the container body gets fewer, air may enter the cylinder together with the liquid. The air entering the cylinder is tends to remain in the cylinder as air bubbles by the air being mixed with the liquid in the cylinder. The air bubbles in the cylinder may cause ejection failure. 
     Therefore, in the trigger type liquid ejector, a configuration is considered in which a recovery passage is provided to bring the inside of the cylinder in communication with the inside of the container body via the inside of the piston guide, the inside of the vertical supply pipe, and the like, for example when the piston is moved to the most retracted position. 
     The above-described vertical supply pipe is formed in a double tubular shape having an inner tube and an outer tube. A valve seat that protrudes from an inner circumferential surface of the inner tube is formed on the inner tube. A ball valve is accommodated in an accommodation space inside the inner tube, which is defined by the valve seat and a ceiling wall of the outer tube, in a state where the ball valve is configured to come in contact with and separate from the valve seat. The accommodation space communicates with the inside of the cylinder and the inside of the ejection barrel via a connection passage formed between an outer circumferential surface of the inner tube and an inner circumferential surface of the outer tube. 
     The operation when the trigger is moved is described in detail. As the trigger is pulled rearward, the piston is moved rearward while being guided by the piston guide formed in the cylinder. Thereby, the inside of the cylinder is pressurized. When the inside of the cylinder is pressurized, as the liquid in the cylinder flows into the accommodation space via the connection passage, the ball valve is pressed against the valve seat. Thereby, communication between the inside of the container body and the connection passage is blocked, and accordingly the liquid in the cylinder passes through the vertical supply pipe and the ejection barrel and is ejected from the ejection hole. 
     Further, as the piston is moved forward according to forward movement (return) of the trigger, the inside of the cylinder is depressurized. When the inside of the cylinder is depressurized, as the liquid in the container body is suctioned into the inner tube, the ball valve is pushed up. Accordingly, the ball valve is separated from the valve seat, and the liquid flows into the cylinder via a gap between the ball valve and the valve seat. 
     DOCUMENT OF RELATED ART 
     Patent Document 
     
         
         Patent Document 1: Japanese Unexamined Patent Application, First Publication No. 2017-47350 
         Patent Document 2: Japanese Unexamined Patent Application, First Publication No. 2007-175609 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     In the above-described trigger type liquid ejector, an upright and inverted posture adaptor may be provided in a lower end portion of the vertical supply pipe in order to enable to eject the liquid in both of the upright and inverted postures (for example refer to Patent Document 2). 
     When the upright and inverted posture adaptor is provided in the trigger type liquid ejector having the recovery passage, communication between the recovery passage and the container body is blocked by the upright and inverted posture adaptor. In this case, the recovery passage may be filled with air bubbles which has been discharged to the recovery passage from the cylinder. Due to air bubbles which cannot pass through a space between the vertical supply pipe and the upright and inverted posture adaptor, the overflow (so-called dripping) of the liquid in the cylinder to the outside, for example via an external air introduction hole of the cylinder may occur. 
     Further, when the trigger type liquid ejector having the upright and inverted posture adaptor is used in the inverted posture, the ball valve separates from the valve seat due to its own weight. In this state, when the piston is moved rearward for ejection, the liquid in the cylinder or the connection passage may flow toward the container body via a gap between the ball valve and the valve seat. That is, in the inverted posture, since it is difficult to efficiently supply the liquid in the cylinder or the connection passage to the ejection barrel, it may be difficult to eject a desired amount of the liquid according to the movement amount of the piston. As a result, variation in the ejection amount of the trigger type liquid ejector may occur between the upright posture and the inverted posture. 
     An object of the present invention is to provide a trigger type liquid ejector capable of suppressing dripping of liquid. 
     An object of the present invention is to provide a trigger type liquid ejector capable of suppressing variation in ejection amount between an upright posture and an inverted posture. 
     Solution to Problem 
     A trigger type liquid ejector according to an aspect of the present invention includes: an ejector body which is mounted on a container body in which a liquid is accommodated; and a nozzle which is disposed in front of the ejector body, and in which an ejection hole configured to eject the liquid is formed, in which the ejector body includes: a vertical supply pipe which extends in an upward/downward direction, and is configured to suction the liquid in the container body; an ejection barrel which is disposed in front of the vertical supply pipe, and is configured to guide the liquid in the vertical supply pipe to the ejection hole; a trigger which is disposed in front of the vertical supply pipe to be movable rearward in a state where the trigger is biased forward; a piston which has a tubular piston body to which the trigger is linked and a sliding portion connected to the piston body, and is configured to move forward and rearward according to forward and rearward movement of the trigger; and a cylinder which has a piston guide inserted into the piston body, and inside of which is pressurized and depressurized by the sliding portion sliding on the cylinder according to forward and rearward movement of the piston, in which a recovery passage is formed in the ejector body, the recovery passage being configured to bring an inside of the cylinder in communication with an inside of the vertical supply pipe via a space between the piston body and the piston guide, in which the vertical supply pipe has a mounting tube into which the recovery passage opens, in which the trigger type liquid ejector further comprises an upright and inverted posture adaptor which is attached into the mounting tube in a state where communication between the recovery passage and an inside of the container body is blocked, in which the upright and inverted posture adaptor includes: an adaptor body which defines a first space and a second space, the first space being configured to bring the inside of the container body in communication with the inside of the vertical supply pipe via an upright posture introduction port, the second space being configured to bring the inside of the container body in communication with the first space via an inverted posture introduction port; and a first switching valve which is configured to block communication between the first space and the second space when the container body, on which the ejector body is mounted, is upright, and is configured to allow communication between the first space and the second space when the container body, on which the ejector body is mounted, is inverted, in which a communication passage is formed between an outer circumferential surface of the upright and inverted posture adaptor and an inner circumferential surface of the mounting tube, the communication passage being configured to bring the recovery passage in communication with the inside of the container body, and in which a minimum value of a flow passage cross-sectional area of the communication passage is larger than a minimum value of a flow passage cross-sectional area of the recovery passage. 
     With this configuration, air bubbles discharged from the cylinder into the recovery passage pass through the communication passage and are discharged into the container body. As a result, it is possible to eject the liquid in both of the upright and inverted postures of the trigger type liquid ejector, and it is possible to suppress dripping of liquid via an external air introduction hole or the like due to air bubbles remaining in the recovery passage or an intermediate space. 
     Particularly, in the aspect, as the minimum value of the flow passage cross-sectional area of the communication passage is larger than the minimum value of the flow passage cross-sectional area of the recovery passage, air bubbles can be efficiently discharged into the container body. 
     In the trigger type liquid ejector according to the aspect, the nozzle may include an accumulator valve which is disposed to be movable rearward in a state where the accumulator valve is biased forward, and is configured to openably close a front end opening portion of the ejection barrel. 
     With this configuration, when the pressure acting on the accumulator valve is equal to or more than a predetermined value, the accumulator valve is moved rearward to allow communication between the ejection hole and the inside of the ejection barrel. Accordingly, it is possible to secure the ejection pressure of the liquid ejected from the ejection hole. 
     Further, even if air bubbles or liquid that cannot be ejected from the ejection hole remains in the cylinder when the pressure acting on the accumulator valve is less than the predetermined value, the air bubbles or liquid remaining in the cylinder can be returned into the container body via the recovery passage and the communication passage. Accordingly, it is possible to suppress dripping of liquid while stabilizing the ejection operation. 
     In the trigger type liquid ejector according to the aspect, the inverted posture introduction port may be disposed on a first side with respect to a center of the upright and inverted posture adaptor in the forward/rearward direction, and the communication passage may be disposed on a second side with respect to the center of the upright and inverted posture adaptor in the forward/rearward direction. 
     With this configuration, the inverted posture introduction port and the communication passage are separated from each other in the forward/rearward direction. Accordingly, for example at the time of the ejection operation in the inverted posture, it is possible to easily suppress air bubbles discharged from the communication passage from flowing again into the cylinder via the inverted posture introduction port. 
     In the trigger type liquid ejector according to the aspect, the upright and inverted posture adaptor may be attached to a lower end portion of the ejector body, the vertical supply pipe may be formed in a topped tubular shape, the vertical supply pipe may include: an inner tube which communicates with the container body, and has the mounting tube and a valve seat protruding from an inner circumferential surface of the inner tube; and an outer tube which surrounds the inner tube, wherein a connection passage is formed between the outer tube and an outer circumferential surface of the inner tube, the connection passage being configured to communicate with the inside of the ejection barrel and the inside of the cylinder, a second switching valve may be accommodated in an accommodation space inside the inner tube, the accommodation space being defined by the valve seat and a ceiling wall of the vertical supply pipe and being configured to communicate with the connection passage, the second switching valve being configured to come in contact with and separate from the valve seat, and where D 1  is a minimum valve of a cross-sectional area of a gap between the second switching valve and the valve seat in a state where the second switching valve separates from the valve seat and comes in contact with the ceiling wall due to its own weight when the container body is inverted, in a direction perpendicular to the valve seat when seen from a vertical cross-sectional view along the upward/downward direction, and D 2  is a minimum valve of an opening area of the valve seat, D 1  and D 2  may be set that 0.62≤D 2 /D 1 ≤3.62. 
     With this configuration, by setting D 2 /D 1  to equal to or more than 0.62, the cross-sectional area D 1  can be made relatively small. This makes it difficult for the liquid flowing in the connection passage to pass through the gap between the second switching valve and the valve seat at the time of the ejection operation in the inverted posture. That is, by making the flow of the liquid into the ejection barrel dominant, among the liquid flowing in the connection passage, as compared with the flow of the liquid through the gap, the liquid can be efficiently introduced into the ejection barrel. As a result, it is possible to suppress the variation in the ejection amount of the trigger type liquid ejector between the upright posture and the inverted posture. 
     By setting D 2 /D 1  to equal to or less than 3.62, it is possible to set the size of the gap such that the liquid suctioned from the container body when the pressure in the cylinder becomes a negative pressure can pass through the gap. Thereby, the piston can be smoothly moved, and therefore the liquid can be efficiently introduced into the cylinder and the operability of the trigger can be improved. 
     In the trigger type liquid ejector according to the aspect, the cross-sectional area D 1  may be set that 1.7 mm 2 ≤D 1 ≤10.0 mm 2 . 
     With this configuration, by setting D 1  to equal to or less than 10.0 mm 2 , the cross-sectional area D 1  can be made relatively small. Accordingly, it is possible to secure the ejection amount in the inverted posture as is described above, and it is possible to suppress the variation in the ejection amount of the trigger type liquid ejector between the upright posture and the inverted posture. 
     By setting D 1  to equal to or more than 17 mm 2 , the liquid can be efficiently introduced into the cylinder when the pressure in the cylinder becomes a negative pressure, and the operability of the trigger can be improved. 
     In the trigger type liquid ejector according to the aspect, the specific gravity of the second switching valve may be larger than that of water. 
     With this configuration, the second switching valve can reliably seat on the valve seat at the time of the upright posture. Thereby, the ejection amount in the upright posture can be stabilized. 
     Advantageous Effects of Invention 
     According to each aspect of the present invention, it is possible to suppress dripping of liquid in the trigger type liquid ejector. 
     According to each aspect of the present invention, it is possible to suppress variation in the ejection amount of the trigger type liquid ejector between the upright posture and the inverted posture. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a partially cross-sectional view of an ejection container according to a first embodiment. 
         FIG. 2  is a plan view of an upright and inverted posture adaptor according to the first embodiment. 
         FIG. 3  is a side view of the upright and inverted posture adaptor and an inner tube according to the first embodiment. 
         FIG. 4  is a cross-sectional view of a vertical supply pipe and an ejection barrel according to the first embodiment. 
         FIG. 5  is a plan view of an upright and inverted posture adaptor according to a second embodiment. 
         FIG. 6  is a side view of the upright and inverted posture adaptor and an inner tube according to the second embodiment. 
         FIG. 7  is a plan view of an upright and inverted posture adaptor according to a modified example of the second embodiment. 
         FIG. 8  is a side view of the upright and inverted posture adaptor and an inner tube according to the modified example of the second embodiment. 
         FIG. 9  is a plan view of an upright and inverted posture adaptor according to another modified example of the second embodiment. 
         FIG. 10  is a side view of the upright and inverted posture adaptor and an inner tube according to the modified example of the second embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings. In the following description, an ejection container formed by attaching a trigger type liquid ejector according to the present invention to a container body will be described. Further, in each of the following embodiments, the same reference numerals may be given to corresponding components, and a description thereof may be omitted. 
     First Embodiment 
     An ejection container  1  shown in  FIG. 1  includes a container body  2  in which a liquid is accommodated, and a trigger type liquid ejector (which will hereinafter be simply referred to as “ejector  3 ”) which is detachably attached to a mouth portion  2   a  of the container body  2 . 
     The ejector  3  includes an ejector body  10 , a nozzle  11  and an upright and inverted posture adaptor  12 . As the liquid accommodated in the container body  2  of the present embodiment, a detergent (which contains a surfactant and becomes in a foamy state) used in a bathroom, a toilet or the like, and having a viscosity equivalent to that of water is preferably used. However, the liquid accommodated in the container body  2  can be appropriately changed. 
     The ejector body  10  includes a vertical supply pipe  14 , an ejection barrel  15 , and a trigger mechanism  16 , and the vertical supply pipe  14  is configured to suction the liquid in the container body  2 , the ejection barrel  15  is configured to guide the liquid suctioned by the vertical supply pipe  14  to the nozzle  11 , and the trigger mechanism  16  is configured to cause the liquid to flow inside the vertical supply pipe  14  and the ejection barrel  15 . 
     In the following description, a direction along a first axis O 1  of the vertical supply pipe  14  (an upper outer tube part  23  to be described later) is referred to as an upward/downward direction. In the upright posture of the ejection container  1 , a side of the container body  2  in the upward/downward direction is referred to as a lower side, and a side of the ejector  3  in the upward/downward direction is referred to as an upper side. In a plan view seen in the upward/downward direction, a direction intersecting the first axis O 1  is referred to as a radial direction. One direction in the radial direction is referred to as a forward/rearward direction, a direction toward which the ejection barrel  15  extends from the vertical supply pipe  14  is referred to as a front side, and an opposite direction thereof is referred to as a rear side. A direction in the radial direction perpendicular to the forward/rearward direction is referred to as a leftward/rightward direction. In the drawings, the first axis O 1  is eccentric rearward with respect to a container axis of the container body  2 . The first axis O 1  may be coaxial with the container axis. 
     The vertical supply pipe  14  includes an outer tube  21  and an inner tube  22 . 
     The outer tube  21  is formed in a multi-stage tubular shape having parts whose diameter increases toward a lower side. Specifically, the outer tube  21  includes an upper outer tube part  23 , and a lower outer tube part  24  extending downward from the upper outer tube part  23 . In the present embodiment, the upper outer tube part  23  and the lower outer tube part  24  are formed in a topped tubular shape. 
     A discharge port  26  which opens forward is formed in an upper portion of a circumferential wall of the upper outer tube part  23 . 
     A supply port  27  and an exhaust port  28  are formed in a middle portion in the upward/downward direction of the circumferential wall of the upper outer tube part  23 , and the supply port  27  and the exhaust port  28  open forward. The supply port  27  is positioned above the exhaust port  28 . The supply port  27  may be positioned below the exhaust port  28 . 
     A communication groove  29  which extends in the upward/downward direction is formed on an inner circumferential surface of the upper outer tube part  23  (the circumferential wall). An upper end portion of the communication groove  29  communicates with the exhaust port  28 . A lower end portion of the communication groove  29  at a lower end edge of the upper outer tube part  23  is opened. The circumferential wall of the upper outer tube part  23  penetrates a top wall of the lower outer tube part  24 . 
     The inner tube  22  is fitted into the outer tube  21  from a lower side of the outer tube  21 . The inner tube  22  is formed in a multi-stage tubular shape having parts whose diameter increases toward a lower side. Specifically, the inner tube  22  includes an upper inner tube part  31 , and a lower inner tube part (a mounting tube)  32  extending downward from the upper inner tube part  31 . 
     The upper inner tube part  31  is disposed coaxially with the upper outer tube part  23 . The upper inner tube part  31  is fitted into the upper outer tube part  23  from a lower side of the upper outer tube part  23 . An upper portion of the upper inner tube part  31  constitutes a small diameter part  34  having an outer diameter smaller than a lower portion of the upper inner tube part  31 . A connection passage S 1  is formed between the inner circumferential surface of the upper outer tube part  23  (the circumferential wall) and an outer circumferential surface of the small diameter part  34 . The connection passage S 1  connects the discharge port  26  and the supply port  27  to each other. An upper end edge of the small diameter part  34  is close to or in contact with a ceiling wall  23   a  of the upper outer tube part  23  from a lower side of the upper outer tube part  23 . 
     As shown in  FIG. 4 , an upper end portion of the small diameter part  34  has an outer diameter that gradually decreases toward an upper side. A rib  33  that protrudes inward in the radial direction is formed on the upper end portion of the small diameter part  34 . The rib  33  extends in the upward/downward direction, and a plurality of the ribs  33  are formed at intervals in the circumferential direction. 
     A valve seat  35  that protrudes inward in the radial direction is provided on the small diameter part  34 , and the valve seat  35  is positioned at a lower end portion of the rib  33 . The valve seat  35  is formed in a tapered tubular shape that extends downward as it goes inward in the radial direction. An accommodation space  40  which accommodates a ball valve (a second switching valve)  41  is formed inside the inner tube  22  and defined by the small diameter part  34 , the valve seat  35 , and the ceiling wall  23   a  of the upper outer tube part  23 . The ball valve  41  is configured to come in contact with and separate from the valve seat  35  due to the pressure inside the accommodation space  40  and its own weight. The ball valve  41  of the present embodiment is formed of a material that has a specific gravity larger than that of water or the liquid accommodated in the container body  2  and is capable of seating on the valve seat  35  by its own weight when the ejection container  1  is in the upright posture. Examples of the material preferably used for the ball valve  41  of the present embodiment include metal (for example, stainless steel). The ball valve  41  may be formed of a material (for example, glass) other than metal as long as it satisfies the above conditions. 
     The accommodation space  40  communicates with the connection passage S 1  via a notch  42  formed in the upper end edge of the small diameter part  34 . When the ball valve  41  seats on the valve seat  35 , the accommodation space  40  blocks communication between the inside of the upper inner tube part  31  and the connection passage S 1 . When the ball valve  41  separates from the valve seat  35 , the accommodation space  40  allows communication between the inside of the upper inner tube part  31  and the connection passage S 1 . 
     The lower inner tube part  32  is fitted into the lower outer tube part  24  from a lower side of the lower outer tube part  24 . A through-hole  48  that passes through the top wall  45  of the lower inner tube part  32  in the upward/downward direction is formed in an inner circumferential portion of the top wall  45 . A lower end portion (a portion protruding from the lower outer tube part  24 ) of the circumferential wall of the upper outer tube part  23  is inserted into the through-hole  48 . The circumferential wall of the upper outer tube part  23  partitions an inside space of the through-hole  48  in the radial direction. An inner portion of the through-hole  48 , which is positioned on an inner side in the radial direction with respect to the circumferential wall of the upper outer tube part  23 , communicates with the inside of the communication groove  29 . An outer portion of the through-hole  48 , which is positioned on an outer side in the radial direction with respect to the circumferential wall of the upper outer tube part  23 , communicates with an external air communication hole  82  (to be described below) via a space defined by the lower outer tube part  24  and the lower inner tube part  32 . 
     An outward flange  51  which protrudes outward in the radial direction is formed on the circumferential wall of the lower inner tube part  32 . In the present embodiment, for example, an axis (which is hereinafter referred to as “second axis O 2 ”) of the lower outer tube part  24  and the lower inner tube part  32  is eccentric forward with respect to the first axis O 1 . 
     The ejector body  10  includes a mounting cap  52  used for attaching the ejector  3  to the container body  2 . The mounting cap  52  is formed in a tubular shape extending in the upward/downward direction. The mounting cap  52  is mounted (for example, screwed) on the mouth portion  2   a  in a state where the outward flange  51  of the lower inner tube part  32  is sandwiched between the mounting cap  52  and an upper end edge of the mouth portion  2   a.    
     The ejection barrel  15  is formed integrally with the upper outer tube part  23 . The ejection barrel  15  protrudes forward from an upper end portion of the upper outer tube part  23 . The inside of the ejection barrel  15  communicates with the connection passage S 1  via the discharge port  26 . 
     The trigger mechanism  16  includes a pump unit  61  having a cylinder  71  and a piston  72 , a cover  62 , a trigger  63 , and an elastic plate  64 . 
     The cylinder  71  has a bottomed tubular shape that opens forward. In the following description, a central axis of the cylinder  71  is referred to as a cylinder axis O 3 . The cylinder axis O 3  extends in the forward/rearward direction. 
     The cylinder  71  includes a housing tube  77 , a piston guide  78 , and a bottom wall  79 , the housing tube  77  and the piston guide  78  extend coaxially with the cylinder axis O 3 , and the bottom wall  79  connects a rear end edge of the housing tube  77  and a rear end edge of the piston guide  78  to each other. 
     The housing tube  77  is fitted into a tube portion  75  for a cylinder which is formed below the ejection barrel  15 . An external air introduction hole  80  is formed in the housing tube  77 , and external air is introduced into the container body  2  via the external air introduction hole  80  according to inflow of the liquid into the cylinder  71 . The tube portion  75  for a cylinder is formed integrally with the vertical supply pipe  14  and the ejection barrel  15 . The tube portion  75  for a cylinder opens forward, and a rear end opening of the tube portion  75  is closed by the upper outer tube part  23 . Both end portions in the forward/rearward direction of the housing tube  77  come in close contact with an inner circumferential surface of the tube portion  75  for a cylinder. In a middle portion in the forward/rearward direction of the housing tube  77 , an annular gap P 1  is formed between an outer circumferential surface of the housing tube  77  and the inner circumferential surface of the tube portion  75  for a cylinder. The gap P 1  communicates with the inside of the cylinder  71  via the external air introduction hole  80 . The gap P 1  communicates with the through-hole  48  via the external air communication hole  82  formed in the tube portion  75  for a cylinder. 
     A communication port  81  that communicates with the supply port  27  is formed in the bottom wall  79 . 
     The piston guide  78  protrudes forward from an inner circumferential edge of the bottom wall  79 . The piston guide  78  is formed in a topped tubular shape that opens rearward. A rear end opening of the piston guide  78  communicates with the exhaust port  28 . A through-hole  83  that passes through a top wall of the piston guide  78  in the forward/rearward direction is formed in the top wall of the piston guide  78 . A depression  84  which recesses inward in the radial direction of the cylinder axis O 3  is formed in a rear end portion of the piston guide  78 . The depression  84  is formed in the piston guide  78  throughout the circumference of the piston guide  78 . The depression  84  may be formed intermittently. 
     The piston  72  is housed inside the housing tube  77  to be movable forward and rearward. The piston  72  includes a piston body  91 , an inner sliding portion  92 , and an outer sliding portion  93 . 
     The piston body  91  is formed in a topped tubular shape that opens rearward. The piston guide  78  is inserted into the piston body  91 . 
     The inner sliding portion  92  extends, from a rear end opening edge of the piston body  91 , inward in the radial direction as it goes rearward. A rear end portion of the inner sliding portion  92  is configured to slide on an outer circumferential surface of the piston guide  78  according to forward and rearward movement of the piston  72 . When the piston  72  reaches the most retracted position, the inner sliding portion  92  separates from the outer circumferential surface of the piston guide  78 . Thereby, the inside of the piston body  91  and the inside of the cylinder  71  come in communication with each other via a space between the inner sliding portion  92  and the depression  84 . 
     The outer sliding portion  93  is connected to a lower end portion of the piston body  91 . The outer sliding portion  93  surrounds the piston body  91 . The outer sliding portion  93  is formed in a tapered tubular shape whose diameter gradually increases, from a middle portion thereof in the forward/rearward direction, as it goes forward and rearward. Front and rear end portions of the outer sliding portion  93  are configured to slide on an inner circumferential surface of the housing tube  77  according to forward and rearward movement of the piston  72 . When the piston  72  is at the frontmost position, the outer sliding portion  93  closes the external air introduction hole  80 . As the piston  72  moves rearward, the outer sliding portion  93  opens the external air introduction hole  80 . 
     The cover  62  covers the vertical supply pipe  14  and the ejection barrel  15  from an upper side, a rear side, and left and right sides. 
     The trigger  63  extends to curve forward as it goes downward. An upper end portion of the trigger  63  is linked to the ejection barrel  15  to be rotatable about an axis C 1  extending in the leftward/rightward direction. A middle portion in the upward/downward direction of the trigger  63  is linked to a front end portion of the piston body  91  to be rotatable about an axis C 2  extending in the leftward/rightward direction and to be movable in the upward/downward direction. The piston  72  moves forward and backward with respect to the cylinder  71  according to the rotational motion of the trigger  63  about the axis C 1 . 
     The elastic plate  64  is interposed between the ejection barrel  15  and the trigger  63 . The elastic plate  64  biases the trigger  63  forward about the axis C 1 . 
     The nozzle  11  protrudes forward from the ejection barrel  15 . The nozzle  11  includes a connecting member  100 , a nozzle body  101 , and an accumulator valve  102 . 
     The connecting member  100  is formed in a topped tubular shape that opens rearward. A front end portion of the ejection barrel  15  is fitted into a circumferential wall of the connecting member  100 . A communication hole  105  that passes through a front wall of connecting member  100  in the forward/rearward direction is formed in the front wall of connecting member  100 . The communication hole  105  communicates with the inside of the ejection barrel  15  via a front end opening portion  15   a  of the ejection barrel  15 . 
     A fitting tube  110  is formed on the front wall of the connecting member  100 . The fitting tube  110  is formed in a tubular shape extending forward and is eccentric downward with respect to an axis of the ejection barrel  15 . 
     The nozzle body  101  is formed in a topped tubular shape that opens rearward. The fitting tube  110  is fitted into a circumferential wall of the nozzle body  101 . A space defined by the connecting member  100  and the nozzle body  101  constitutes an accumulator chamber  115 . 
     A nozzle cap  112  having an ejection hole  112   a  is mounted on a front wall of the nozzle body  101 . 
     The accumulator valve  102  is accommodated in the accumulator chamber  115  to be movable rearward in a state where the accumulator valve  102  is biased forward by a coil spring  120 . The accumulator valve  102  seats on a valve seat  121  formed on the front wall of the nozzle body  101  to close the ejection hole  112   a . A small diameter piston portion  102   a  is formed in a rear half portion of the accumulator valve  102 , and a large diameter piston portion  102   b  is formed in a front half portion of the accumulator valve  102 . The accumulation valve  102  is configured such that the pressure of the liquid introduced into the accumulation chamber  115  via the communication hole  105  is applied to both piston portions  102   a  and  102   b . When this pressure is equal to or more than a predetermined value, due to the difference in pressure receiving area between the piston portions  102   a  and  102   b , the accumulator valve  102  is moved rearward to open the ejection hole  112   a.    
     The trigger type liquid ejector  3  of the present embodiment includes a lid  130  as a blocking member configured to block communication between the inside of the nozzle  11  and the outside via the ejection hole  112   a . The lid  130  is provided at the nozzle  11 , and closes the ejection hole  112   a  so as to be capable of opening and closing the ejection hole  112   a  from the front. An upper end portion of the lid  130  is mounted on the front wall of the nozzle body  101  to be rotatable about an axis extending in the leftward/rightward direction. The blocking member is not limited to the lid  130 , and for example, a configuration in which communication between the inside of the nozzle body  101  and the outside via the ejection hole  112   a  is blocked by relatively rotating the nozzle body  101  with respect to the connecting member  100  may be employed. 
     The upright and inverted posture adaptor  12  is mounted on a lower end portion of the vertical supply pipe  14 . The upright and inverted posture adaptor  12  enables the ejection container  1  in both of the upright posture (a posture in which the mouth portion  2   a  is directed upward) and the inverted posture (a posture in which the mouth portion  2   a  is directed downward) to eject the liquid in the container body  2 . 
     The upright and inverted posture adaptor  12  includes a first fitting member  140 , a second fitting member  141 , and a partition member  142 , the first fitting member  140  and the second fitting member  141  are assembled in the upward/downward direction, and the partition member  142  partitions a space between the first fitting member  140  and the second fitting member  141 . The first fitting member  140 , the second fitting member  141 , and the partition member  142  constitute an adaptor body of the present embodiment. 
     The first fitting member  140  is formed in a multi-stage tubular shape having parts whose diameter decreases toward an upper side. Specifically, the first fitting member  140  includes a small diameter part  145 , a middle diameter part  146 , and a large diameter part  147 . 
     The small diameter part  145  is disposed coaxially with the first axis O 1 . An upper portion of the small diameter part  145  is fitted into the upper inner tube part  31 . A first flange  150  that protrudes outward in the radial direction is formed on the small diameter part  145 , and the first flange  150  is positioned above a lower end edge of the small diameter part  145 . 
     The middle diameter part  146  extends downward from an outer circumferential edge of the first flange  150 . The middle diameter part  146  is disposed coaxially with the second axis O 2 . The middle diameter part  146  is fitted into the lower inner tube part  32  from a lower side of the lower inner tube part  32 . Thereby, a lower end opening of the lower inner tube part  32  is closed. A second flange  152  that protrudes outward in the radial direction is formed on a lower end edge of the middle diameter part  146 . The second flange  152  is close to or in contact with a lower end edge of the lower inner tube part  32  from a lower side of the lower inner tube part  32 . 
     The large diameter part  147  extends downward from an outer circumferential edge of the second flange  152 . An inverted posture introduction port  153  that passes through the large diameter part  147  in the radial direction is formed in a front portion (a portion positioned on a front side of the second axis O 2 ) of the large diameter part  147 . 
     The partition member  142  includes a first communication tube  160  and a second communication tube  161 . 
     The first communication tube  160  is disposed coaxially with the first axis O 1 . A lower end portion (a portion protruding downward from the first flange  150 ) of the small diameter part  145  is fitted into the first communication tube  160  from an upper side of the first communication tube  160 . 
     The second communication tube  161  is connected to the front of the first communication tube  160 . The second communication tube  161  has a diameter that gradually decreases toward a lower side. In the present embodiment, a space defined by the second communication tube  161  and the first fitting member  140  constitutes a valve chamber (a second space)  165 . The valve chamber  165  communicates with the inside of the container body  2  via the inverted posture introduction port  153 . A ball valve (a first switching valve)  164  is accommodated in the valve chamber  165 . As the ball valve  164  comes in contact with and separates from a lower end opening edge of the second communication tube  161 , the ball valve  164  opens and closes a lower end opening of the second communication tube  161 . 
     The second fitting member  141  includes a blocking portion  170  and a fixing tube  171 . 
     The blocking portion  170  is formed in a bottomed tubular shape that opens upward. The blocking portion  170  is fitted into the large diameter part  147  in a state where the partition member  142  is sandwiched between the blocking portion  170  and the large diameter part  147 . 
     The fixing tube  171  passes through a bottom wall of the blocking portion  170  in a rear portion (at a position coaxially with the first axis O 1 ) of the blocking portion  170 . A suction pipe  175  is fitted into a lower portion of the fixing tube  171 . An upper end opening (an upright posture introduction port)  171   a  of the fixing tube  171  communicates with the inside of the first communication tube  160 . Therefore, the first communication tube  160  communicates with the inside of the container body  2  via the fixing tube  171 . The second communication tube  161  communicates with the inside of the container body  2  via the inverted posture introduction port  153 . 
     A space defined by the blocking portion  170 , the fixing tube  171  and the second communication tube  161  constitutes a connection flow path  180  that connects the valve chamber  165  and the fixing tube  171  to each other. The connection flow path  180  communicates with the inside of the fixing tube  171  via a slit  182  formed in the fixing tube  171 . A space extending from the connection flow path  180  to the small diameter part  145  via the slit  182  constitute a first space of the present embodiment. 
     Here, in the present embodiment, a flow path extending through the through-hole  83  of the piston guide  78 , the inside of the piston guide  78 , the exhaust port  28 , the communication groove  29 , and the through-hole  48  constitutes a recovery passage S 2  that is configured to return air bubbles and the like remaining in the cylinder  71  to the inside of the container body  2 . The recovery passage S 2  communicates, via the through-hole  48 , with an intermediate space S 3  defined by the lower inner tube part  32  and the first fitting member  140 . 
     As shown in  FIGS. 2 and 3 , a communication passage S 4  that is configured to bring the intermediate space S 3  in communication with the inside of the container body  2  is formed in the first fitting member  140 . The communication passage S 4  is formed by recessing the middle diameter part  146 , the large diameter part  147 , the first flange  150  and the second flange  152 . Specifically, the communication passages S 4  are formed on both right and left sides of the small diameter part  145 , and each communication passage S 4  is disposed rearward with respect to the second axis O 2  (the center in the forward/rearward direction of the upright and inverted posture adaptor  12 ). Each communication passage S 4  opens upward, rearward, and outward in the radial direction. A lower end portion of the communication passage S 4  is disposed below the lower inner tube part  32  and communicates with the inside of the container body  2 . 
     In the present embodiment, the minimum value of the flow passage cross-sectional area (cross-sectional area perpendicular to an opening direction) of the communication passage S 4  is larger than the minimum value of the flow passage cross-sectional area of the recovery passage S 2 . The minimum value of the flow passage cross-sectional area of the recovery passage S 2  is the minimum valve among the flow passage cross-sectional areas perpendicular to the opening direction of the through-hole  83  of the piston guide  78 , the inside of the piston guide  78 , the exhaust port  28 , the communication groove  29 , and the through-hole  48 . In the present embodiment, the minimum value of the flow passage cross-sectional area of the communication passage S 4  is set to be larger than air bubbles generated in the cylinder  71 . 
     When the ball valve  41  seats on the valve seat  35 , the accommodation space  40  blocks communication between the inside of the upper inner tube part  31  (a portion below the accommodation space  40 ) and the connection passage S 1 . As shown in  FIG. 4 , when the ball valve  41  separates from the valve seat  35 , a gap between an inner circumferential surface of the valve seat  35  and the ball valve  41  is formed in the accommodation space  40 . Accordingly, the inside of the upper inner tube part  31  comes in communication with the connection passage S 1  via the gap P 2 . 
     Here, the cross-sectional area of the gap P 2  when the ball valve  41  is in contact with the ceiling wall  23   a  of the upper outer tube part  23  at a position on the axis O 1  is denoted by D 1 . That is, the cross-sectional area D 1  is a flow passage cross-sectional area of an annular space (the gap P 2 ) formed between the ball valve  41  and the valve seat  35 , in a direction perpendicular to a seat surface (a contact surface with the ball valve  41 ) of the valve seat  35  when seen from a vertical cross-sectional view along the upward/downward direction. In the present embodiment, the cross-sectional area D 1  is preferably set to 1.7 mm 2 ≤D 1 ≤10.0 mm 2 , and is more preferably set to 34 mm 2 ≤D 1 ≤6.9 mm 2  In the ejector  3  of the present embodiment, the cross-sectional area D 1  is 1.7 mm 2  when the movement amount of the ball valve  41  (the movement amount of the ball valve  41  from a state of seating on the valve seat  35  to a state of coming in contact with the ceiling wall  23   a ) is 0.3 mm, and the cross-sectional area D 1  is 10.0 mm 2  when the movement amount is 1.5 mm. 
     The opening area (the minimum opening area) of a lower end opening portion of the valve seat  35  is denoted by D 2 . In the present embodiment, the diameter φ of the lower end opening portion of the valve seat  35  is set to 2.8 mm. 
     In this case, in the present embodiment, the relationship of the cross-sectional area D 1  with respect to the opening area D 2  satisfies the following condition.
 
0.62≤ D   2 / D   1 ≤ 3 . 62   (1)
 
     In the present embodiment, the minimum cross-sectional area D 3  of the discharge port  26  is set to 5.31 mm 2 . In this case, the relationship of the cross-sectional area D 1  with respect to the minimum cross-sectional area D 3  satisfies the following condition.
 
0.53≤ D   3 / D   1 ≤ 3 . 1   (2)
 
     By setting D 3 /D 1  to equal to or more than 0.53, during the ejection operation in the inverted posture, it is possible to increase the flow amount of the liquid flowing into the ejection barrel  15 , among the liquid flowing in the connection passage S 1 , as compared with the flow amount of the liquid passing through the gap P 2 . As a result, it is possible to suppress the variation in the ejection amount of the ejector  3  between the upright posture and the inverted posture. 
     By setting D 3 /D 1  to equal to or less than 3.1, the liquid can be efficiently introduced into the cylinder  71 . It is more preferable that 0.77≤D 3 /D 1 ≤1.5 is satisfied in order to exert the effects described above. 
     Next, the operation of the ejection container  1  will be described. First, the ejection operation in the upright posture will be described. When the ejection container  1  is in the upright posture, the ball valve  41  seats on the valve seat  35  due to its own weight, and the ball valve  164  seats on the lower end opening edge of the second communication tube  161  due to its own weight. That is, the ball valve  164  blocks communication between the first space and the valve chamber  165  when the container body  2 , on which the ejector body  10  is mounted, is upright. 
     When the ejection container  1  is in the upright posture, in order to eject the liquid in the container body  2 , the trigger  63  is pulled rearward against a biasing force of the elastic plate  64 . The piston  72  is moved rearward according to rearward movement of the trigger  63 , and therefore the inside of the cylinder  71  is pressurized. As the inside of the cylinder  71  is pressurized, the liquid in the cylinder  71  flows into the accommodation space  40  via the connection passage S 1 , and thereby the ball valve  41  is pressed against the valve seat  35 . Accordingly, communication between the inside of the container body  2  and the connection passage S 1  is blocked. As a result, the liquid in the cylinder  71  is introduced into the ejection barrel  15  via the connection passage S 1 . As the liquid is introduced into the ejection barrel  15 , the inside of the ejection barrel  15  is pressurized. As a result, the insides of the small diameter piston portion  102   a  and the large diameter piston portion  102   b  in the accumulator valve  102  are pressurized through the communication hole  105 . 
     In the present embodiment, the inner diameter of the large diameter piston portion  102   b  is larger than the inner diameter of the small diameter piston portion  102   a . Therefore, due to the difference in pressure receiving area between the small diameter piston portion  102   a  and the large diameter piston portion  102   b , pressure directed rearward is applied to the accumulator valve  102 . When the pressure in the small diameter piston portion  102   a  and the large diameter piston portion  102   b  is equal to or more than a predetermined value, the accumulator valve  102  is moved rearward against a forward biasing force by the coil spring  120 . As a result, a front end portion of the accumulator valve  102  is separated from the valve seat  121 , and thereby the inside of the ejection barrel  15  comes in communication with the ejection hole  112   a  via the communication hole  105 , the inside of the accumulator valve  102 , and a gap between the front end portion of the accumulator valve  102  and the valve seat  121 . Accordingly, the liquid is ejected from the ejection hole  112   a.    
     When the operation of pulling the trigger  63  is stopped, the supply of the liquid from the cylinder  71  into the ejection barrel  15  via the connection passage S 1  of the vertical supply pipe  14  is stopped. At this time, as the accumulator valve  102  is moved forward due to the forward biasing force by the coil spring  120 , the front end portion of the accumulator valve  102  seats on the valve seat  121 , and communication between the inside of the ejection barrel  15  and the ejection hole  112   a  is blocked. 
     The trigger  63  is biased forward to return to its original position by the elastic recovering force of the elastic plate  64 . As the piston  72  is moved forward according to forward movement of the trigger  63 , the pressure in the cylinder  71  becomes a negative pressure. At this time, due to the negative pressure in the cylinder  71 , the liquid in the container body  2  flows into the upright and inverted posture adaptor  12  via the suction pipe  175 . The liquid flowing into the upright and inverted posture adaptor  12  flows through the inside of the inner tube  22  and pushes up the ball valve  41 . Accordingly, the ball valve  41  is separated from the valve seat  35 , and the liquid is introduced into the cylinder  71  via the connection passage S 1  and the communication port  81  (the supply port  27 ). Accordingly, the liquid can be provided upon the next ejection. 
     Next, the ejection operation in the inverted posture will be described. When the ejection container  1  is in the inverted posture, the ball valve  41  separates from the valve seat  35  due to its own weight, and the ball valve  164  separates from the lower end opening edge of the second communication tube  161  due to its own weight. That is, the ball valve  164  allows communication between the first space and the valve chamber  165  when the container body  2 , on which the ejector body  10  is mounted, is inverted. 
     When the ejection container  1  is in the inverted posture, as the trigger  63  is pulled rearward, the inside of the cylinder  71  is pressurized. As a result, the liquid in the cylinder  71  and the connection passage S 1  is introduced into the ejection barrel  15  and the accommodation space  40 . Here, the gap P 2  between the ball valve  41  and the valve seat  35  is formed such that the flow resistance of the liquid passing through the ejection barrel  15  is smaller than the flow resistance of the liquid passing through the gap P 2 . As a result, the liquid is positively introduced into the ejection barrel  15  and is ejected from the ejection hole  112   a  as is described above. 
     When the trigger  63  returns forward after the liquid is ejected, similar to the case of the upright posture, the pressure in the cylinder  71  becomes a negative pressure. As a result, the liquid flowing into the valve chamber  165  via the inverted posture introduction port  153  flows into the first communication tube  160  via the lower end opening of the second communication tube  161 , the connection flow path  180 , and the slit  182 . The liquid flowing into the first communication tube  160  flows through the inside of the inner tube  22 , and then is introduced into the cylinder  71  via the connection passage S 1  and the communication port  81  (the supply port  27 ). Accordingly, the liquid can be provided upon the next ejection. 
     Here, in the ejection container  1 , for example when the remaining amount of the liquid in the container body  2  gets fewer, there is a possibility that air may enter the cylinder  71  together with the liquid. The air entering in the cylinder  71  tends to remain in the cylinder  71  as air bubbles, which may cause ejection failure. 
     In the present embodiment, when the trigger  36  is moved to the most retracted position, the inside of the piston body  91  comes in communication with the inside of the cylinder  71  via the space between the inner sliding portion  92  and the depression  84 . As a result, air bubbles remained in the cylinder  71  flows into the piston body  91  via the space between the inner sliding portion  92  and the depression  84 . The air bubbles flowing into the piston body  91  are discharged from the piston body  91  by passing through the recovery passage S 2  (the flow path extending through the through-hole  83 , the inside of the piston guide  78 , the exhaust port  28 , the communication groove  29 , and the through-hole  48 ). The air bubbles passing through the recovery passage S 2  reach the intermediate space S 3  and then are discharged into the container body  2  via the communication passage S 4 . 
     The trigger type liquid ejector  3  according to the present embodiment includes the ejector body  10  mounted on the container body  2  in which the liquid is accommodated, and the nozzle  11  disposed in front of the ejector body  10  and in which the ejection hole  112   a  configured to eject the liquid is formed. The ejector body  10  includes the vertical supply pipe  14 , the ejection barrel  15 , the trigger  63 , the piston  72 , and the cylinder  71 , the vertical supply pipe  14  extends in the upward/downward direction and is configured to suction the liquid in the container body  2 , the ejection barrel  15  is disposed in front of the vertical supply pipe  14  and is configured to guide the liquid in the vertical supply pipe  14  to the ejection hole  112   a , the trigger  63  is disposed in front of the vertical supply pipe  14  to be movable rearward in a state where the trigger  63  is biased forward, the piston  72  has the piston body  91  which is formed in a tubular shape and to which the trigger  63  is linked, and the inner sliding portion  92  and the outer sliding portion  93  which are connected to the piston body  91 , the piston  72  is configured to move forward and rearward according to forward and rearward movement of the trigger  63 , the cylinder  71  has the piston guide  78  which is inserted into the piston body  91 , and the inside of the cylinder  71  is pressurized and depressurized by the inner sliding portion  92  and the outer sliding portion  93  sliding on the cylinder  71  according to forward and rearward movement of the piston  72 . The recovery passage S 2  is formed in the ejector body  10  and is configured to bring the inside of the cylinder  71  in communication with the inside of the vertical supply pipe  14  via the space between the piston body  91  and the piston guide  78 . The vertical supply pipe  14  has the lower inner tube part  32  into which the recovery passage S 2  opens. The trigger type liquid ejector  3  includes the upright and inverted posture adaptor  12  which is attached into the lower inner tube part  32  in a state where communication between the recovery passage S 2  and the inside of the container body  2  is blocked. The upright and inverted posture adaptor  12  has the first fitting member  140 , the second fitting member  141 , the partition member  142 , and the ball valve  164 , the first fitting member  140 , the second fitting member  141 , and the partition member  142  define the first space which is configured to bring the inside of the container body  2  in communication with the inside of the vertical supply pipe  14  via the upper end opening  171   a , and the valve chamber  165  which is configured to bring the inside of the container body  2  in communication with the first space via the inverted posture introduction port  153 , and the ball valve  164  is configured to block communication between the first space and the valve chamber  165  when the container body  2 , on which the ejector body  10  is mounted, is upright, and is configured to allow communication between the first space and the valve chamber  165  when the container body  2 , on which the ejector body  10  is mounted, is inverted. The communication passage S 4  is formed between the outer circumferential surface of the upright and inverted posture adaptor  12  and the inner circumferential surface of the lower inner tube part  32 , and is configured to bring the recovery passage S 2  in communication with the inside of the container body  2 . The minimum value of the flow passage cross-sectional area of the communication passage S 4  is larger than the minimum value of the flow passage cross-sectional area of the recovery passage S 2 . 
     In the present embodiment, the upright and inverted posture adaptor  12  is attached into the lower end portion of the vertical supply pipe  14  in a state where communication between the recovery passage S 2  and the inside of the container body  2  is blocked, and the communication passage S 4  that is configured to bring the recovery passage S 2  in communication with the inside of the container body  2  is formed between the upright and inverted posture adaptor  12  and the vertical supply pipe  14 . 
     According to this configuration, air bubbles discharged from the cylinder  71  into the recovery passage S 2  pass through the communication passage S 4  and are discharged into the container body  2 . As a result, it is possible for the ejection container  1  to eject the liquid in the container body  2  in both of the upright and inverted postures, and it is possible to suppress dripping of the liquid via the external air introduction hole  80  or the like due to air bubbles filled inside the recovery passage S 2 . 
     Particularly, in the present embodiment, as the minimum value of the flow passage cross-sectional area of the communication passage S 4  is larger than the minimum value of the flow passage cross-sectional area of the recovery passage S 2 , air bubbles can be efficiently discharged into the container body  2 . 
     Further, particularly in the ejector  3  having the accumulator valve  102 , when priming (an operation of discharging air from the cylinder  71  and introducing liquid into the cylinder  71 ) is performed, there is a possibility that air discharged from the cylinder  71  does not completely go out from the ejection hole  112   a , and may wander between the inside of the cylinder  71  and the inside of the vertical supply pipe  14  or the inside of the ejection barrel  15 . In this case, it may be difficult to smoothly introduce the liquid into the cylinder  71 . 
     In the present embodiment, even in this case, by moving the trigger  63  to the most retracted position to bring the inside of the piston body  91  in communication with the inside of the cylinder  71 , air in the cylinder  71  is discharged into the container body  2  via the recovery passage S 2 , the intermediate space S 3 , and the communication passage S 4 . Accordingly, it becomes easier to discharge the air from the cylinder  71  at the time of the priming, and the liquid can be smoothly introduced into the cylinder  71 . 
     In the present embodiment, the nozzle  11  includes the accumulator valve  102  that is disposed to be movable rearward in a state where the accumulator valve  102  is biased forward, and is configured to openably close the front end opening portion  15   a  of the ejection barrel  15 . 
     With this configuration, when the pressure acting on the accumulator valve  102  is equal to or more than a predetermined value, the accumulator valve  102  allows communication between the ejection hole  112   a  and the inside of the ejection barrel  15 , and accordingly, it is possible to secure the ejection pressure of the liquid ejected from the ejection hole  112   a.    
     Further, even if air bubbles or liquid that cannot be ejected from the ejection hole  112   a  remains in the cylinder  71  when the pressure acting on the accumulator valve  102  is less than the predetermined value, the air bubbles or liquid remaining in the cylinder  71  can be returned into the container body  2  via the recovery passage S 2  and the communication passage S 4 . Accordingly, it is possible to suppress dripping of liquid while stabilizing the ejection operation. 
     In the present embodiment, the inverted posture introduction port  153  is disposed forward with respect to the second axis O 2 , and the communication passage S 4  is disposed rearward with respect to the second axis O 2 . 
     With this configuration, the inverted posture introduction port  153  and the communication passage S 4  are separated from each other in the forward/rearward direction. Accordingly, for example at the time of the ejection operation in the inverted posture, it is possible to easily suppress the air bubbles discharged from the communication passage S 4  from flowing again into the cylinder  71  via the inverted posture introduction port  153 . 
     In the present embodiment, the relationship of the cross-sectional area D 1  with respect to the opening area D 2  is set that 0.62≤D 2 /D 1 ≤3.62. 
     With this configuration, by setting D 2 /D 1  to equal to or more than 0.62, the cross-sectional area D 1  can be made relatively small. This makes it difficult for the liquid flowing in the connection passage S 1  to pass through the gap P 2  between the ball valve  41  and the valve seat  35  at the time of the ejection operation in the inverted posture. That is, by making the flow of the liquid into the ejection barrel  15  dominant, among the liquid flowing in the connection passage S 1 , as compared with the flow of the liquid through the gap P 2 , the liquid can be efficiently introduced into the ejection barrel  15 . As a result, it is possible to suppress the variation in the ejection amount of the ejector  3  between the upright posture and the inverted posture. 
     By setting D 2 /D 1  to equal to or less than 3.62, it is possible to set the size of the gap P 2  such that the liquid suctioned from the container body  2  when the pressure in the cylinder  71  becomes a negative pressure can pass through the gap P 2 . Thereby, the piston  72  can be smoothly moved, and therefore the liquid can be efficiently introduced into the cylinder  71  and the operability of the trigger  63  can be improved. 
     Further, in the present embodiment, the cross-sectional area D 1  is set that 1.7 mm 2 ≤D 1 ≤10.0 mm 2 . 
     With this configuration, by setting D 1  to equal to or less than 100 mm 2 , the cross-sectional area D 1  can be made relatively small. Accordingly, it is possible to secure the ejection amount of the ejector  3  in the inverted posture, and it is possible to suppress the variation in the ejection amount of the ejector  3  between the upright posture and the inverted posture. 
     By setting D 1  to equal to or more than 1.7 mm 2 , the liquid can be efficiently introduced into the cylinder  71  when the pressure in the cylinder  71  becomes a negative pressure, and the operability of the trigger  63  can be improved. 
     In the present embodiment, the specific gravity of the ball valve  41  is larger than that of water. 
     With this configuration, the ball valve  41  can reliably seat on the valve seat  35  at the time of the upright posture. Thereby, the ejection amount of the ejector  3  in the upright posture can be stabilized. 
     Second Embodiment 
     Next, a second embodiment according to the present invention will be described. 
     As shown in  FIGS. 5 and 6 , in the present embodiment, the communication passages S 4  are formed in the first fitting member  140  on left and right sides with respect to the second axis O 2 . Each communication passage S 4  is formed in a fan shape whose width gradually increases toward an outer side (a direction away from the second axis O 2 ) in the leftward/rightward direction. Each communication passage S 4  opens upward and outward in the leftward/rightward direction. 
     A partition wall  300  that bulges upward from a bottom wall of the communication passage S 4  is formed on a front half portion of the communication passage S 4 . The partition wall  300  is formed flush with the second flange  152  and the large diameter part  147 . An upper end surface of the partition wall  300  and the second flange  152  are close to or in contact with the lower end edge of the lower inner tube part  32  from a lower side of the lower inner tube part  32 . The partition wall  300  may be positioned inside the second flange  152  and the large diameter part  147 . 
     According to this configuration, the same effects as those of the above-described embodiment are exhibited, and the following effects are further exhibited. 
     Since the partition wall  300  is disposed between the communication passage S 4  and the inverted posture introduction port  153 , even when the distance between the communication passage S 4  and the inverted posture introduction port  153  becomes smaller, it is possible to suppress air bubbles discharged from the communication passage S 4  from flowing into the inverted posture introduction port  153 . 
     Note that, as shown in  FIGS. 7 and 8 , the height of the bottom wall of the communication passage S 4  can be appropriately changed as long as at least a portion of the communication passage S 4  communicates with the inside of the container body  2 . 
     Further, in the above embodiment, the configuration in which the partition wall  300  is provided on the front half portion of the communication passage S 4  has been described, but a configuration without the partition wall  300  as shown in  FIGS. 9 and 10  may be employed. In addition, the size, position, number, and the like of the communication passage S 4  can be appropriately changed. 
     While preferred embodiments of the present invention have been described and illustrated above, it should be understood that these embodiments are not to be considered as limiting the present invention. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. The present invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims. 
     In the above embodiments, the configuration in which, when the piston  72  reaches the most retracted position, the inside of the piston body  91  and the inside of the cylinder  71  come in communication with each other via the depression  84  has been described, but the present invention is not limited thereto. The position of the piston  72  is not limited as long as at least a portion of the inside of the piston body  91  communicates with the inside of the cylinder  71 . For example, a groove or the like may be formed in the piston guide  78  or the inner sliding portion  92  to bring the inside of the piston body  91  in communication with the inside of the cylinder  71  via the groove or the like. 
     In the above embodiments, the configuration in which the communication passage S 4  is formed in the upright and inverted posture adaptor  12  has been described, but the present invention is not limited thereto. The communication passage S 4  may be formed in at least one of the upright and inverted posture adaptor  12  and the vertical supply pipe  14 , between the outer circumferential surface of the upright and inverted posture adaptor  12  and the inner circumferential surface of the vertical supply pipe  14  (the lower inner tube part  32 ). 
     In the above embodiments, the configuration in which the ball valve  41  is used as the second switching valve has been described, but the present invention is not limited thereto, and any configuration can be employed as the second switching valve as long as it can come in contact with and separate from the valve seat. 
     In the above embodiments, the configuration in which the ball valve  41  is configured to come in contact with the ceiling wall  23   a  of the outer tube  21  formed in a topped tubular shape has been described, but the inner tube  22  may be formed in a topped tubular shape. 
     Besides, it is possible to appropriately replace the constituent elements in the above embodiments with well-known constituent elements, and the above-described modified examples may be combined as appropriate without departing from the scope of the present invention. 
     INDUSTRIAL APPLICABILITY 
     The present invention can be applied to a trigger type liquid ejector. 
     REFERENCE SIGNS LIST 
     
         
         
           
               2  Container body 
               2   a  Mouth portion 
               3  Trigger type liquid ejector 
               10  Ejector body 
               11  Nozzle 
               12  Upright and inverted posture adaptor 
               14  Vertical supply pipe 
               15  Ejection barrel 
               15   a  Front end opening portion 
               21  Outer tube 
               22  Inner tube 
               23   a  Ceiling wall 
               32  Lower inner tube part (mounting tube) 
               35  Valve seat 
               40  Accommodation space 
               41  Ball valve (second switching valve) 
               63  Trigger 
               71  Cylinder 
               72  Piston 
               78  Piston guide 
               91  Piston body 
               92  Inner sliding portion (sliding portion) 
               93  Outer sliding portion (sliding portion) 
               102  Accumulator valve 
               112   a  Ejection hole 
               140  First fitting member (adaptor body) 
               141  Second fitting member (adaptor body) 
               142  Partition member (adaptor body) 
               153  Inverted posture introduction port 
               164  Ball valve (first switching valve) 
               165  Valve chamber (second space) 
               171   a  Upper end opening (upright posture introduction port) 
             S 1  Connection passage 
             S 2  Recovery passage 
             S 4  Communication passage