JP2005098280A - Liquid discharging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid discharging device lightly driven and preventing liquid from leaking to the outside. <P>SOLUTION: In the liquid discharging device 3, the liquid is sucked through an intake part 25, filled in a pump chamber P, and is discharged through a discharge valve 31 by pushing operation of a piston 41. The piston 41 is slidably supported by a cylinder 21, so that liquid can slightly leaks through a fitting clearance between the cylinder 21 and the piston 41 along with the pushing operation of the piston 41. Further, a pumping member 51 is connected with a cylinder 21, and the pumping member has a tank chamber 53 therein whose capacity is changed according to reciprocating motions of the piston 41, and which receives the liquid leaked from the fitting clearance. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a quantitative discharge type liquid discharge device, for example, for injecting a chemical solution into a living body in a fixed amount, or to incorporate a liquid for cooling the heat generating component incorporated in various devices having a heat generating electronic component. The present invention relates to a liquid ejecting apparatus that can be suitably used for sending a fixed amount.

  Conventionally, a liquid discharge device using a plunger pump for discharging a predetermined amount of liquid is known (see, for example, Patent Document 1).

In the liquid discharge device described in Patent Document 1, a plunger-type piston is slidably fitted into a cylinder hole in which one end of a cylinder is closed, and an intake valve and a discharge valve are attached to the cylinder. The suction valve is a check valve that opens so that liquid is sucked into the pump chamber when the pressure of the pump chamber formed by the piston and the cylinder is reduced during the pulling-out operation of the piston. The discharge valve is a check valve that opens so that liquid is discharged from the pump chamber due to an increase in pressure in the pump chamber when the piston is pushed in. A seal ring for improving the close contact with the inner surface of the cylinder hole is attached to the tip and center of the piston. For this seal ring, an O-ring capable of elastic deformation such as an elastomer is usually used.
JP 2001-315713 A (paragraphs 0008-0011, FIGS. 1-2)

  By the way, a treatment for injecting a drug solution into a diabetic patient with a portable small pump is known as CSII (Continuous subcutaneous Insulin Infusion), that is, a continuous subcutaneous insulin infusion treatment. In this treatment, the drug solution injection speed is extremely fast, and the amount of the drug solution injected is as small as several μcc. This small amount of high-speed chemical injection must be guaranteed by the discharge operation of the small pump.

  The plunger pump described in Patent Document 1 uses a seal ring to partition the fitting gap between the cylinder and the piston so that there is no liquid leakage, and the entire chemical liquid filled in the pump chamber is pushed in as the piston is pushed. By pressurizing, the chemical solution is discharged from the discharge valve.

  The seal ring that is elastically in close contact with the cylinder hole inner surface strongly rubs the cylinder hole inner surface every time the piston is reciprocated. Due to this sliding friction, it is inevitable that as the plunger pump is used for a longer period of time, the wear of the soft seal ring advances as compared with the cylinder, and the sealing performance decreases. In addition, the stronger the intimate force of the seal ring to the inner surface of the cylinder hole, the more the sliding friction increases, and the wear of the seal ring easily proceeds.

  Thus, the plunger pump described in Patent Document 1 has a large frictional resistance because the seal ring that is elastically in close contact with the cylinder hole inner surface strongly rubs the cylinder hole inner surface every time the piston is reciprocated. For this reason, the thing which generate | occur | produces big drive energy is required for the drive part which drives a pump.

  Moreover, the plunger pump described in Patent Document 1 is capable of discharging an accurate amount at the beginning of use, but with the deterioration due to wear of the seal ring due to prolonged use, Liquid leakage occurs.

  In addition, the amount of liquid leakage gradually increases as wear of the seal ring progresses. As a result, when the plunger pump described in Patent Document 1 is applied as a CSII pump, there is a possibility that the discharge characteristics may change due to the liquid leakage, so that it can be used continuously for a long period of time. However, further ingenuity is required. In particular, when the CSII pump is used in a form of implantation embedded in a living body, the period of implantation is assumed to be several years or more. For this reason, the plunger pump described in Patent Document 1 is not suitable for assuring accurate chemical discharge over the implantation period.

  The problem to be solved by the present invention is to provide a liquid ejection device that can be driven lightly and can prevent liquid leakage to the outside.

  In order to solve the above problems, a liquid discharge device of the present invention is a liquid discharge device that discharges a liquid filled in a pump chamber by a push-in operation of a piston with respect to a cylinder, and with the push-in operation of the piston, Liquid is leaked through a fitting gap between the cylinder and the piston, and a pumping member that forms a tank chamber for receiving the leaked liquid is connected to the cylinder.

  In this invention, with the reciprocating movement of the piston, the fitting gap between the cylinder and the piston is used as a flow path, and the pumping member can leak from the cylinder to the tank chamber formed inside, but more Liquid leakage to the outside is prevented by a pumping member. Since the flow rate passing through the fitting gap, that is, the leakage amount can be defined by the piston and the dimensional accuracy of the piston, the leakage amount can be managed constant while obtaining a sufficient hydraulic pressure to push the discharge valve. . The liquid leaking into the tank chamber enters and exits the fitting gap with the reciprocation of the piston, and is eventually sucked into the pump chamber and discharged from the pump chamber. As described above, in the liquid ejection device of the present invention, the cylinder does not have a seal ring that is elastically strong and rubbed against the cylinder, so that the driving force of the piston can be small.

  In order to solve the above problems, the present invention provides a cylinder in which the cylinder has a cylinder main body having a head sliding hole and a piston through hole communicating with the head sliding hole and is connected to the cylinder main body. A head that is slidable in the head sliding hole by partitioning the inside of the head sliding hole into the pump chamber that communicates with the discharge valve and a suction chamber that communicates with the suction portion. A shaft portion that is continuous with the head and is slidably penetrated into the piston through hole, and a fitting clearance between the head sliding hole and the head, and a fitting clearance between the piston through hole and the shaft portion. A tank chamber for receiving a liquid leaking from the latter fitting gap at least in the latter fitting gap, and leaking with the pushing operation of the piston. A pumping member which is deformed following the movement is linked to the cylinder.

  In this invention, with the reciprocating movement of the piston, it is possible to leak into the tank chamber inside the pumping member using the fitting gap between the piston through hole and the shaft portion of the piston as a flow path. Liquid leakage to the outside is prevented by a pumping member. The liquid leaking into the tank chamber enters and exits the fitting gap with the reciprocation of the piston, and is eventually sucked into the pump chamber and discharged from the pump chamber. As described above, in the liquid discharge device of the present invention, the piston does not have a seal ring that is elastically strongly and closely rubbed against the cylinder, so that the driving force of the piston can be small.

  In order to solve the above problems, the present invention is a liquid discharge device that discharges, through a discharge valve, a liquid that is sucked through a suction portion and filled in a pump chamber by a pushing operation of a piston into a cylinder. The cylinder has a piston through-hole, and the shaft portion of the piston is slidably supported by the piston through-hole, and liquid is leaked from the fitting clearance between the piston through-hole and the piston as the piston is pushed in. A reservoir that forms a reservoir chamber that receives liquid leaking from the fitting gap is connected to the cylinder, a tank chamber that communicates with the reservoir chamber is provided inside, and the reservoir chamber is deformed following the reciprocating movement of the piston. A pumping member is connected to the reservoir.

  In this invention, with the reciprocating movement of the piston, it is possible to leak into the reservoir chamber inside the reservoir using the fitting gap between the piston through hole and the shaft portion of the piston as a flow path. Liquid leakage into the tank is prevented by a pumping member having a tank chamber communicating with the reservoir chamber. The liquid leaking into the reservoir chamber enters and exits the fitting gap as the piston reciprocates, and eventually is sucked into the pump chamber and discharged from the pump chamber. As described above, in the liquid discharge device of the present invention, the piston does not have a seal ring that is elastically strongly and closely rubbed against the cylinder, so that the driving force of the piston can be small.

  In the preferred embodiment of the present invention, the fitting gap is formed between the piston through hole and the shaft portion having a circular cross section formed narrower than the piston through hole.

  In a preferred embodiment of the present invention, the piston passage has a fluid passage groove extending along the axial direction of the piston, and the inner surface of the piston passage hole is divided into a plurality of regions by the fluid passage groove. .

  In order to solve the above problems, the present invention is a liquid discharge device that discharges, through a discharge valve, a liquid that is sucked through a suction portion and filled in a pump chamber by a pushing operation of a piston into a cylinder. Liquid is leaked from a fitting gap between the head sliding hole of the cylinder and the head of the piston, and a tank chamber for receiving liquid leaking from the fitting gap is provided on the inner side, and the piston is deformed following the reciprocating movement of the piston. A pumping member to be connected to the cylinder, the suction portion is provided in communication with the pump chamber, and a check valve is provided in the suction portion that opens when the pump chamber becomes low pressure and closes when the pressure becomes high. .

  In this invention, with the reciprocating movement of the piston, the fitting clearance between the cylinder head sliding hole and the piston head can be used as a flow path, and the pumping member can leak liquid from the cylinder to the tank chamber formed inside it. However, liquid leakage to the outside is prevented by the pumping member. The liquid leaking into the tank chamber enters and exits the fitting gap with the reciprocation of the piston, and is eventually sucked into the pump chamber and discharged from the pump chamber. As described above, the liquid discharge apparatus of the present invention has a small piston driving force because the cylinder does not have a seal ring that is elastically strongly and rubbed against the cylinder head sliding hole. That's it.

  In a preferred embodiment of the present invention, the pumping member is a bellows.

  Moreover, in the preferable form of this invention, the biasing body which urges | biases the said bellows in the direction extended in the axial direction is provided.

  In a preferred embodiment of the present invention, a reservoir tank communicating with the tank chamber is provided.

  In order to solve the above-mentioned problem, the liquid discharge device of the present invention is a liquid discharge device that discharges the liquid sucked through the suction portion and filled in the pump chamber through the discharge valve by pushing the piston into the cylinder. The piston is slidably supported by the piston through-hole of the cylinder, and the liquid is leaked from the fitting clearance between the piston through-hole and the piston as the piston is pushed in. And a reservoir chamber that communicates with the reservoir chamber through a liquid return portion, and the volume is changed following the reciprocating movement of the piston, and the liquid supplied to the pump chamber is supplied to the suction portion by the volume change. And a tank chamber for sucking and collecting from the tank.

  In this invention, the pump chamber is not completely sealed, and the liquid filled in the pump chamber leaks into the reservoir chamber and the tank chamber using the piston through-hole and the piston fitting gap as a flow path when the piston is pushed in. Is possible. The flow rate that passes through the fitting gap, that is, the amount of leakage can be defined by the piston through hole and piston dimensional accuracy, etc., so that the amount of leakage can be managed uniformly while obtaining sufficient fluid pressure to open the discharge valve. It is. Accordingly, a fixed amount of liquid can be discharged from the pump chamber through the discharge valve each time the piston is pushed in without the piston having a seal ring that is elastically and strongly in close contact with the cylinder. The liquid leaking into the reservoir chamber does not continue to be stored in the reservoir chamber, and is returned through the liquid return portion to the tank chamber whose volume is expanded when the piston is pulled out. As a result, the liquid leaking into the reservoir chamber is eventually supplied from the tank chamber to the pump chamber and repeatedly discharged from the pump chamber through the discharge valve as described above. Liquid leaking from the gap does not leak outside. As described above, since the piston does not have a seal ring, the driving force of the piston can be reduced.

  In the present invention, the reservoir chamber can be provided also as a storage portion for storing the end portion to which the piston is pushed out during the pushing operation of the piston. However, the reservoir chamber is provided in communication with the storage portion separately from the storage portion. Is also possible. In the present invention, the reservoir chamber can also serve as a part of the liquid return portion. In the present invention, the liquid return portion is preferably provided so as to penetrate the cylinder, but may be constituted by piping or the like that bypasses the cylinder. In the present invention, it is not hindered to provide a suction valve in the suction part. The present invention is suitable for injecting a very small amount of a chemical into a living body, but can also be applied to applications in which a relatively small amount of liquid is quantitatively discharged.

  According to a preferred embodiment of the present invention, there is provided a liquid discharge device that discharges, through a discharge valve, a liquid that is sucked through a suction portion and filled in a pump chamber by pushing a piston into a cylinder. And a piston through hole having a second guide hole portion communicating with a discharge passage having a larger cross section than the first guide hole portion and the discharge valve disposed therein. The cylinder having a cylinder cover to be formed, a first shaft portion guided by the first guide hole portion, and a section larger than the first shaft portion is inserted into and removed from the second guide hole portion. A piston having a second shaft portion guided by the second guide hole portion and penetrating through the piston through-hole so as to reciprocate, and a tank chamber for storing the liquid sucked through the suction portion on the inner side Yes And a pumping member that is deformed following the reciprocal movement of the piston and changes the volume of the tank chamber by this deformation, and the piston is located at a position where the second shaft portion is pulled out from the second guide hole. A liquid introducing means for communicating between the tank chamber and the second guide hole when disposed; and the reservoir chamber and the tank chamber communicating with a fitting gap between the first guide hole and the first shaft portion. And a liquid return portion that communicates with each other.

  In a preferred embodiment of the present invention, the liquid return portion includes a communication hole that penetrates the cylinder.

  Moreover, in the preferable form of this invention, the said cylinder and the said piston are made from the material of the same hardness.

  In a preferred embodiment of the present invention, the liquid introducing means is a groove provided in the axial direction on a peripheral portion between the first shaft portion and the second shaft portion of the piston, and the groove is And open to the peripheral surface of the piston and open toward the first shaft portion.

  In a preferred embodiment of the present invention, the cross section of the first guide hole and the cross section of the first shaft part are each circular, and the cross section of the second guide hole is larger than the cross section of the first guide hole. And the pump chamber closed by the second shaft portion when the piston is pushed in has a circular shape with a cross section of the second shaft portion larger than that of the first shaft portion. It is formed between the guide hole and the first shaft portion.

  In a preferred embodiment of the present invention, the pumping member is a bellows.

  Further, in a preferred embodiment of the present invention, the discharge flow path has a conical valve seat portion and a circular hole continuous to the downstream side of the valve seat portion, and the discharge valve is the conical valve seat portion. And a valve body having a plurality of ribs projecting from a peripheral surface of the valve body and slidingly contacting the circular hole.

  According to the present invention, since a seal ring that is elastically intimately rubbed against the cylinder is not used, it is possible to drive lightly, and to allow liquid leaking from between the cylinder and the piston to Alternatively, since the liquid is received in the reservoir chamber of the reservoir, the reservoir tank, or the reservoir chamber between the cylinder and the cylinder cover, a liquid discharge device capable of preventing liquid leakage to the outside can be provided.

(First embodiment)
The first embodiment of the present invention will be described below with reference to FIGS.

  Reference numeral 1 in FIG. 1 indicates a liquid injection unit used for, for example, CSII treatment as a liquid injection unit. The chemical solution injection unit 1 can be suitably used, for example, by being embedded in a human body (living body), but can also be used by being attached to the body surface of the living body using an attaching tool such as a belt.

  The chemical injection unit 1 is formed in a sealed case 2 with a chemical discharge device 3, a drive mechanism 4, a liquid storage tank 5, a control device 6, a power source 7, and the like as a liquid discharge device built therein.

  One end of a suction pipe 11 is connected to the chemical liquid discharge device 3, and the other end of the suction pipe 11 is connected to a liquid storage tank 5. A discharge pipe 12 that functions as a catheter is connected to the chemical liquid discharge device 3, and a distal end portion 12 c of the discharge pipe 12 has a needle shape, for example, to discharge a chemical liquid (liquid) discharged from the chemical liquid discharge device 3. It is connected to an appropriate place such as a blood vessel in a living body to be injected. By operating the chemical liquid discharge device 3, when the chemical liquid discharge device 3 is discharging, a fixed amount of chemical liquid to be discharged is discharged into the living body through the pipe 12, and when the chemical liquid discharge device 3 is inhaling, A chemical solution corresponding to the injected liquid amount is supplied from the storage tank 5 to the chemical solution discharge device 3 through the suction pipe 11.

  The liquid storage tank 5 for storing a predetermined amount of chemical liquid preferably has a bellows capable of changing the tank volume so that the pressure of the chemical liquid inside thereof is kept substantially constant, and the chemical liquid is stored at a predetermined pressure. It is also preferable to pre-load. However, the pressure of the chemical solution may be atmospheric pressure. A supply pipe 13 is connected to the liquid storage tank 5. A detachable supply cap 13 a is attached to the tip of the supply pipe 13. When the chemical injection unit 1 is embedded in the body, the supply cap 13a is disposed on the body surface. By opening the replenishment cap 13a in a timely manner, the chemical solution can be replenished to the liquid storage tank 5 through the replenishment pipe 13.

  The drive mechanism 4 includes a drive motor 15, a feed screw 16, a movable nut 17, and a connecting member 18. As the drive motor 15, an electric motor capable of forward / reverse rotation capable of position control, such as a stepping motor, can be preferably used. The feed screw 16 is connected to the rotation shaft of the drive motor 15. The movable nut 17 is screwed to the feed screw 16 and is fixed to the connecting member 18. The connecting member 18 is slidably fitted to a guide member 19 fixed to the motor frame of the drive motor 15 and is prevented from rotating. For this reason, the movable nut 17 and the connecting member 18 are reciprocated at high speed in the axial direction of the feed screw 16 as the drive motor 15 rotates forward and backward.

  The drive mechanism 4 and the chemical solution discharge device 3 are arranged in parallel so as to be positioned on an extension line of each central axis. The distal end portion of the connecting member 18 is connected to the joint 3 a of the chemical liquid discharging device 3. Therefore, the chemical liquid discharge device 3 can be operated by the power of the drive mechanism 4.

  The control device 6 includes a macro processor and a memory 6a. Drive profile data is stored in advance in the memory 6a. The drive profile data includes a plurality of types of liquid discharge pattern data, such as chemical injection pattern data, such as total injection amount per day, injection amount for each time zone of the day, and injection amount before and after a meal. Includes data such as upper and lower limits. This drive profile data is selected in advance according to the user. Detection signals from the position sensors 8 and 9 are input to the control device 6. The position sensor 8 detects, for example, the forward position (piston push-in position) of the connecting member 18, and the position sensor 9 detects the backward position (piston withdrawal position) of the connecting member 18. The control device 6 controls the drive of the drive motor 15 via the driver circuit 6b of the control device 6 based on the detection signals of the position sensors 8, 9 and the drive profile data stored in the memory 6a in advance. .

  As the power source 7, it is preferable to use a battery, for example, a primary battery that can be used continuously over several years. However, when the chemical solution injection unit 1 is not embedded in the living body, a secondary battery can be used. The power of the power source 7 is supplied to the control device 6 and the drive motor 15 of the drive mechanism 4.

  The chemical liquid ejection device 3 will be described with reference to FIGS. The chemical liquid discharge device 3 includes a cylinder 21 having a cylinder cover 61, a discharge valve 31, a piston 41, a pumping member 51, a groove 71 functioning as a liquid introduction means, and a communication hole 81 as a liquid return portion, for example. ing.

  The cylinder 21 is made of a material excellent in rust prevention and wear resistance and chemical resistance, for example, a metal, and more preferably stainless steel such as SUS304. The shape of the cylinder 21 viewed from the front is, for example, a quadrangular shape with four corners chamfered, and the size of one side is, for example, 10 mm.

  A piston through hole 22 that functions as a cylinder hole is provided at the center of the cylinder 21 so as to penetrate in the thickness direction of the cylinder 21, for example. As shown in FIGS. 3 to 6, the piston through-hole 22 has a first guide hole 22a and a second guide hole 22b continuous to one end of the hole 22a. The cross section of the second guide hole 22b is larger than the cross section of the first guide hole 22a. In order to easily obtain this relationship by round hole drilling, the cross sections of both guide hole portions 22a and 22b are, for example, similar in shape. Specifically, both the holes 22a and 22b are made of circular holes that share the central axis, and the diameter of the second guide hole 22b is larger than the diameter of the first guide hole 22a. .

  The first and second guide hole portions 22a and 22b are not limited to circular holes and can be made of square holes. In order to obtain the cross-sectional relationship between the guide hole portions 22a and 22b, a circular hole or a square hole is formed in the cylinder 21, and the inner surface of the through hole is centered from one end of the through hole to an intermediate position in the longitudinal direction. It is also possible to provide one or more grooves extending in the axial direction, and the hole area with the groove may be the second guide hole part 22b, and the hole area without the groove may be the first guide hole part 22a. In this case, the cross section of the second guide hole portion 22b is larger than the first guide hole portion 22a by the cross section of the groove.

  The hole diameter of the second guide hole portion 22b is, for example, 1 mm. The cylinder 21 is provided with a recess 23 that opens to the front surface 21a. A first guide hole 22 a is opened at the center of the recess 23. The recess 23 can be omitted. The second guide hole portion 22 b is opened on the back surface 21 b of the cylinder 21.

  The cylinder 21 is provided with a suction part 25. The suction part 25 is made of a hole provided so as to face the piston through hole 22 from the peripheral surface of the cylinder 21. A connector 11 a included in the suction pipe 11 is screwed into the suction portion 25. Since the inside of the connector 11a communicates with the suction part 25, the chemical solution is introduced into the suction part 25 through the connector 11a. 2 to 4, reference numeral 11b denotes a square nut portion used when the connector 11a is screwed, and reference numeral 26 denotes a seal ring for making the periphery of the screwed portion of the connector 11a liquid-tight.

  A discharge passage 27 is provided in the cylinder 21. The discharge flow path 27 is made of, for example, a hole that is located on the opposite side of the suction portion 25 with the piston passage hole 22 as a boundary and is provided so as to face the piston passage hole 22 from the peripheral surface of the cylinder 21. 2 Opened in the guide hole 22b. A connector 12 a included in the discharge pipe 12 is screwed into the discharge channel 27. Since the inside of the connector 12a communicates with the second guide hole portion 22b via the discharge channel 27, the chemical solution is led through the connector 12a. 2 to 4, reference numeral 12b denotes a square nut portion used when the connector 12a is screwed, and reference numeral 28 denotes a seal ring for liquid-tightening around the screwed portion of the connector 12a.

  As shown in FIGS. 2 and 6, the discharge flow path 27 includes a small-diameter inlet portion 27a communicating with the second guide hole portion 22b, and a conical valve continuous to the downstream side (drug outflow side) of the inlet portion 27a. It has a seat portion 27b and a large-diameter circular hole portion 27c continuous on the downstream side of the valve seat portion 27b.

  A discharge valve 31 is attached to the circular hole 27 c of the discharge flow path 27. Each of the discharge valves 31 includes a metal valve body 32 and a coil spring 33. The valve body 32 has a cylindrical valve body 32a and a plurality of, for example, three or more ribs 32b.

  As shown in FIGS. 2 and 6, the valve main body 32 a has a cylindrical shape and has a conical end portion 32 ah that is brought into contact with and separated from the conical valve seat portion 27 b at one end thereof. The maximum diameter of the end portion 32ah is larger than the diameter of the inlet portion 27a, which is the minimum diameter of the conical valve seat portion 27b, and smaller than the diameter of the circular hole portion 27c, which is the maximum diameter of the conical valve seat portion 27b. Therefore, the maximum diameter of the valve body 32a is smaller than the diameter of the circular hole portion 27c. Each rib 32b extends from the peripheral surface of the valve main body 32a in the axial direction of the valve main body 32a so as to project integrally. These ribs 32b can be slidably contacted with the inner surface of the circular hole 27c.

  The coil spring 33 is sandwiched between the valve body 32a and the connector 12a in a compressed state. The conical end portion 32ah is pressed against the conical valve seat portion 27b by the elastic force of the coil spring 33. For this reason, the discharge valve 31 maintains the valve closed state until the hydraulic pressure in the second guide hole 22 b becomes larger than the elastic force of the coil spring 33, and the hydraulic pressure becomes larger than the elastic force of the coil spring 33. The valve is in an open state only for as long as it is.

  The piston 41 passes through the piston through hole 22 so as to be capable of reciprocating in the axial direction thereof, and is slidably supported by the through hole 22. As shown in FIGS. 3 to 6, the piston 41 has a first shaft portion 42 and a second shaft portion 43.

  The first shaft portion 42 includes a shaft portion guided by the first guide hole portion 22a and has a cross section corresponding to the cross section of the first guide hole portion 22a. A fitting gap (not shown) is provided between the first shaft portion 42 and the first guide hole portion 22a, and a slight amount of liquid leakage is enabled through this gap.

  The cross section of the second shaft portion 43 has a cross section corresponding to the cross section of the second guide hole portion 22 b and is larger than the cross section of the first shaft portion 42. The second shaft portion 43 is a shaft portion that is inserted into and removed from the second guide hole portion 22b from the back surface 21b side in accordance with the axial movement of the piston 41 and is guided to the second guide hole portion 22b in the inserted state.

  When the second shaft 43 is inserted into the second guide hole 22b, that is, when the piston 41 is pushed into the piston through hole 22, the opening of the second guide hole 22b to the back surface 21b is closed. By closing the second guide hole portion 22b in this way, a pump chamber P (see FIG. 4) is formed between the second guide hole portion 22b and the first shaft portion.

  One end of the pump chamber P located in the pushing direction of the piston 41 is closed by a step portion formed at the boundary between the first and second guide hole portions 22a and 22b. The other end side portion of the pump chamber P located in the pulling direction of the piston 41 is closed by the second shaft portion 43 as described above. The pump chamber P is formed as a cylindrical volume-variable space corresponding to a difference in diameter between the second guide hole portion 22b and the first shaft portion 42 having a circular cross section.

  A fitting gap (not shown) is also provided between the second shaft portion 43 and the second guide hole portion 22b, and a small amount of liquid can be leaked through this gap. The amount of liquid leakage between this part and the first shaft portion 42 and the first guide hole portion 22a can be set arbitrarily. However, in consideration of the concentration of the chemical solution and the moving speed of the piston 41, at most, It is desirable to set it to 20% or less of the discharged liquid amount.

  The inner surface of the piston through-hole 22 and the peripheral surfaces of the first and second shaft portions 42 and 43 of the piston 41 are made of a polished surface with a predetermined surface accuracy that has been subjected to a polishing process. It does not prevent the plating layer from being applied. The cylinder 21 and the piston 41 may be made of a material having the same hardness, preferably the same metal material, in order to suppress mutual wear as much as possible. However, the present invention is not limited to this, and the piston 41 can be made of a hard synthetic resin having the same hardness as that of the cylinder 21. Further, a metal plating layer having the same hardness as the other may be provided on one of the inner surface of the piston through hole 22 and the peripheral surface of the piston 41 without using the same hardness as the whole.

  The piston 41 is provided with a liquid introducing means for guiding the chemical liquid to the second guide hole portion 22b opened to the back surface 21b when the piston 41 is in the drawing position shown in FIGS. It has been. The liquid introducing means is composed of one or more grooves 71 provided in the peripheral portion between the first shaft portion 42 and the second shaft portion 43 so as to extend in the axial direction of the piston 41. In this configuration, only the groove 71 is precisely machined in the peripheral portion of the piston 41, and no special parts are required to make the liquid introduction means, and the liquid introduction means is provided easily and at low cost by the groove machining. Excellent in terms.

  As shown in detail in FIG. 6, these grooves 71 are opened on the peripheral surface of the piston 41 and are opened toward the first shaft portion 42. For example, at least a portion near the first shaft portion 42 of the rib-like portion 45 (see FIG. 6) that partitions the groove 71 is always inserted in a state of being guided by the second guide hole portion 22b. For this reason, in the state where the groove end 71a on the second shaft portion 43 side of the groove 71 protrudes from the back surface 21b, the chemical liquid can be introduced from the tank chamber described later through the groove 71. The introduction of the chemical solution is stopped when the groove 71 is completely immersed in the second guide hole portion 22b, in other words, when the second shaft portion 43 is inserted into the second guide hole portion 22b.

  A retaining ring 46 is attached to the distal end portion of the first shaft portion 42 that forms one end of the piston 41. When the retaining ring 46 hits the bottom of the recess 23, further pulling out of the piston 41 is restricted.

  A member presser 47 is attached to the distal end portion of the second shaft portion 43 forming the other end of the piston 41 via a screw 48, and the screw is passed through a holding plate 49 screwed to the member presser 47. 50 is rotatably mounted. The joint 3a is screwed onto the screw 50. Therefore, the piston 41 is reciprocated at a high speed with respect to the cylinder 21 in the axial direction via the joint 3 a that is advanced and retracted by the drive mechanism 4.

  The pumping member denoted by reference numeral 51 in FIGS. 3 to 5 is made of, for example, a cylindrical bellows having both ends opened. The pumping member 51 has chemical resistance and flexibility. An end 51a on the large-diameter portion side of the pumping member 51 is fitted into an annular groove 21c provided on the back surface 21b of the cylinder 21, and is liquid-tightly connected to the cylinder 21 by an annular press plate 52 screwed to the back surface 21b. It is fixed. An end 51 b on the small diameter side of the pumping member 51 is sandwiched between the other end of the piston 41 and the member presser 47, and is fixed to the other end of the piston 41 in a liquid-tight manner.

  Accordingly, the pumping member 51 is provided with the tank chamber 53 formed between the pump 21 and the piston 41 so as to be deformed following the reciprocating movement of the piston 41. The volume of the tank chamber 53 is changed with the flexible deformation of the pumping member 51. The tank chamber 53 covers and hides the protruding portion of the piston 41 from the cylinder 21.

  As the pumping member 51, a flexible bellows capable of expanding and contracting can be used instead of the bellows, and flexible deformation is easy, which is preferable in terms of a small driving load. However, using a bellows has a simple structure. In addition, the increase in the hydraulic pressure when deformed so as to reduce the volume is not concentrated locally and can be received by the entire bellows, so that the durability is excellent. Therefore, it is preferable in terms of obtaining durability of the chemical liquid discharging device 3.

  The cylinder 21 has a cylinder cover 61 screwed to the front surface 21a. The cover 61 is made of a chemical-resistant metal or synthetic resin, and forms a reservoir chamber 62 in the cylinder 21. The reservoir chamber 62 receives a chemical that leaks through a fitting gap (not shown) between the first guide hole portion 22a and the first shaft portion. At the center of the cylinder cover 61, there is provided a concave accommodating portion 63 that accommodates the tip end portion of the first shaft portion 42 when the piston 41 is pushed in. The wall surface 62a of the housing portion 63 is a stopper surface that prevents the piston 41 from being pushed further when the retaining ring 46 comes into contact when the piston 41 is pushed in for a predetermined stroke (for example, 3 mm) or more for some reason. It is supposed to function as. 3 to 6, reference numeral 64 indicates a seal ring that is fitted into an annular groove 21 d provided on the front surface 21 a of the cylinder 21 and is pressed by the cylinder cover 61, whereby the liquid tightness of the reservoir chamber 62 is indicated. Is held.

  The reservoir chamber 62 and the tank chamber 53 communicate with each other through one or more communication holes 81. That is, a plurality of communication holes 81 are formed around the piston passage hole 22 and penetrate the cylinder 21 in the thickness direction. Therefore, one end of each communication hole 81 opens into the reservoir chamber 62, and the other end opens into the tank chamber 53. One of the communication holes 81 is provided so as to intersect with the suction part 25. As a result, the suction portion 25 is communicated with the reservoir chamber 62 and the tank chamber 53 via the communication hole 81 intersecting with the suction portion 25.

  Note that the passage that communicates the suction portion 25 and the tank chamber 53 and the communication hole 81 may be provided separately. The configuration in which the liquid return portion is formed by the communication hole 81 opened in the cylinder 21 does not require a member for the liquid return portion, and does not require time and effort such as mounting. For this reason, it is excellent in that the configuration is simple, it does not become a factor of enlargement or failure, and can be realized at low cost.

  The chemical solution ejection device 3 having the above configuration is used as follows while maintaining a state where the chemical solution including the tank chamber 53 and the reservoir chamber 62 is filled with the chemical solution.

  3 and 5 show the non-operating state of the chemical liquid ejecting apparatus 3, and FIG. 4 shows the operating state of the chemical liquid ejecting apparatus 3.

  In the non-operating state, the drive mechanism 4 is in a standby state, the piston 41 is pulled out, and the second shaft portion 43 is disposed outside the piston through hole 22. For this reason, the second shaft portion 43 side of the groove 71 protrudes into the tank chamber 53, and the tank chamber 53 and the second guide hole portion 22 b communicate with each other through the groove 71. The pumping member 51 is held in an extended state, and the discharge valve 31 is held in a closed state. Further, it is determined by the control device 6 that the position sensor 9 detects the connecting member 18 and is in the piston extraction position.

  When the drive mechanism 4 is operated, the piston 41 fitted in the piston through hole 22 is pushed. Along with the movement of the piston 41, the pumping member 51 is flexibly deformed so as to shorten its length while expanding outward, and the internal pressure of the tank chamber 53 is increased. However, the discharge valve 31 does not open with the hydraulic pressure at this time.

  Under this state, when the second shaft portion 43 of the piston 41 is inserted into the second guide hole portion 22b of the piston through-hole 22, the second guide hole portion 22b is closed and the pump chamber P filled with the chemical solution. Is formed. The pump chamber P is formed in a cylindrical shape between the inner surface of the second guide hole portion 22b and the peripheral surface of the first shaft portion 42 facing the second guide hole portion 22b, and one end of the pump chamber P is a boundary between the guide hole portions 22a and 22b. The other end is closed by the second shaft portion 43 as described above.

  With the pushing operation of the piston 41 further progressing from this point, the chemical liquid already filled in the pump chamber P is pressurized by the second shaft portion 43, and the liquid pressure is given by the coil spring 33 of the discharge valve 31. It will be better than the valve closing force. As a result, the discharge valve 31 is opened and the chemical solution in the pump chamber P is discharged and injected into the blood vessel of the living body through the pipe 12. The pushing operation of the piston 41 is continued until the position sensor 8 detects the connecting member 18 and the control device 6 determines that it is in the piston pushing position.

  The amount of the chemical liquid discharged from the pump chamber P through the discharge valve 31 is based on the pushing stroke of the piston 41 regardless of the volume change of the pump chamber P accompanying the flexible deformation of the pumping member 51. In this case, a very small amount of chemical liquid is leaked into the reservoir chamber 62 through a fitting gap (not shown) between the first guide hole portion 22a and the first shaft portion 42 fitted therein, and the second guide hole portion. A very small amount of chemical solution is also leaked into the tank chamber 53 through a fitting gap (not shown) between the second shaft portion 43 and the second shaft portion 43 fitted therein. Since these leakage amounts can be defined by the dimensional accuracy of each part of the piston through-hole 22 and each part of the piston 41, the pushing speed of the piston 41, etc., the leakage amount is obtained while obtaining a sufficient fluid pressure to open the discharge valve 31. It can be managed to a certain extent. For this reason, it is possible to accurately discharge and inject a small amount of chemical solution.

  Moreover, the first shaft portion 42 is passed through the pump chamber P. As a result, since the pump chamber P is formed in a cylindrical shape, the volume of the pump chamber P is small, and the pump chamber P has a small volume. Long length. Since the second shaft portion 43 is pushed into the small-volume pump chamber P with a predetermined stroke to perform the discharge operation, it is possible to ensure a long pushing stroke of the second shaft portion 43. Thereby, the influence of the variation in the movement amount of the piston 41 is suppressed, and a more accurate amount of the chemical solution can be discharged.

  At the time of the above-described chemical solution discharge operation, the discharge valve 31 is opened by sliding the plurality of ribs 32b on the inner surface of the circular hole portion 27c of the outflow passage 27. The valve body 32 does not tilt. As a result, there is no possibility that the valve body 32 may be galvanized by the inner surface of the circular hole portion 27c, and the discharge valve 31 can be normally and reliably opened and discharged to discharge the chemical liquid.

  When the valve is opened, the chemical solution flows out through a gap formed between the inner surface of the circular hole 27c and the peripheral surface of the valve body 32a. Furthermore, when the valve is closed, the conical end portion 32ah of the valve main body 32a is seated on the conical valve seat portion 27b, so that the seating state can be stabilized. The conical valve seat portion 27b may be omitted, and the conical end portion 32ah may be inserted into the inlet portion 27a to close the inlet portion 27a.

  When the liquid pressure in the pump chamber P becomes lower than the valve closing force as the chemical liquid is discharged, the discharge valve 31 is closed by the valve closing force, so that the discharge of the chemical liquid is completed. Thereafter, the drive motor 15 of the drive mechanism 4 is reversely operated, and the piston 41 is returned to the drawing position. Thereby, one injection of the chemical solution is completed, and such an operation is repeated by the control device 6 at predetermined time intervals, for example.

  As the piston 41 is pulled back to the pulled-out position, the pumping member 51 is flexibly deformed so as to be extended, and the hydraulic pressure in the tank chamber 53 inside thereof is lowered. For this reason, a part of the chemical solution filled in the reservoir chamber 62 is returned to the tank chamber 53 through each communication hole 81, and an amount of the chemical solution corresponding to the injection amount passes through the suction pipe 11 and the suction part 25. The tank chamber 53 is replenished from the liquid storage tank 5.

  In this case, the second shaft portion 43 protrudes from the second guide hole portion 22b through the stage in which the hydraulic pressure in the pump chamber P gradually decreases as the piston 41 is pulled out, and the groove end 71a side of the groove 71 enters the tank chamber 53. Protruding. For this reason, since the tank chamber 53 and the second guide hole 22b communicate with each other through the groove 71, the liquid in the tank chamber 53 flows in and is filled so as to be sucked into the second guide hole 22b. Prepare for discharge operation.

  As described above, the chemical liquid discharge device 3 that discharges a quantity in consideration of the liquid leakage between the piston through hole 22 and the piston 41 is a seal ring that is elastically and strongly in close contact with the inner surface of the piston through hole 22. Without using the fixed amount, the fixed amount of chemical solution can be discharged from the pump chamber P through the discharge valve 31. Thus, unlike the configuration using the seal ring that is elastically strongly rubbed against the inner surface of the piston through-hole 22, there is no change in the discharge amount due to wear of the seal ring. In addition, the wear caused by the sliding of the piston 41 with respect to the piston through hole 22 can be suppressed by the chemical solution that is about to leak from between the two.

  Therefore, the change in the discharge amount based on the wear over a long period of use over several years is suppressed, and the stable quantitative discharge performance of the chemical solution can be maintained over a long period of time. At the same time, the driving force of the piston 41 can be reduced, and a motor having a smaller torque and hence a smaller size can be used as the driving motor 15. As described above, since the piston 41 does not have a seal ring that is elastically strongly and rubbed against the inner surface of the piston through-hole 22, there is a possibility that the abrasion powder of the seal ring accompanying wear is mixed into the chemical liquid. Absent.

  The chemical liquid leaking into the reservoir chamber 62 is returned through the communication hole 81 to the tank 53 chamber whose volume is enlarged when the piston 41 is pulled out as described above. For this reason, the chemical liquid does not continue to increase in the reservoir chamber 62 with the repeated pushing operation of the piston 41. That is, the volume of the reservoir chamber 62 does not require a volume sufficient to store the chemical liquid that leaks over the entire period of the chemical liquid ejection device 3, and may be much smaller than that. Therefore, the provision of the reservoir chamber 62 is not a factor for increasing the size of the chemical liquid ejection device 3. Thereby, it is suitable for downsizing of the chemical liquid ejection device 3.

  Further, as described above, the liquid leaked from the fitting gap into the reservoir chamber 62 and the liquid leaked from the fitting gap and received in the tank chamber 53 will eventually be removed from the tank chamber 53 with the repeated pushing operation. Since the liquid is supplied to the pump chamber P and discharged through the discharge valve 31, the liquid leaking from the fitting gap does not leak outside.

  In the above-described operation of the chemical liquid ejection device 3, the piston 41 is not only supported by the first guide hole portion 22a at the first shaft portion 42 at all times, but also is a rib-like portion 45 that partitions the groove 71 in the piston withdrawn state. Is supported by the second guide hole 22b, and the second shaft 43 is supported by the second guide hole 22b when the piston is pushed in. As described above, the piston 41 is supported by the piston through-hole 22 at both sides thereof with the communicating portion of the discharge flow path 27 with respect to the second guide hole 22b as a boundary. Thereby, there is no fear of wobbling as in the case where the piston 41 is cantilevered, and the reciprocating movement along the axial direction can be performed stably, and the quantitative discharge operation is smooth.

  Further, as described above, the piston 41 is pushed in so that the second shaft portion 43 closes the second guide hole portion 22b and the pump chamber P is formed. Therefore, the suction valve for sealing the pump chamber P is provided. There is no particular need. For this reason, since only one valve is required as the chemical solution discharge device 3, the structure is simple, the number of parts and the number of assembling steps can be reduced, and the cost can be reduced.

  Second and third embodiments of the present invention will be described. Since these embodiments are basically the same as those of the first embodiment, the same portions are denoted by the same reference numerals as those of the first embodiment, description of the configuration and operation thereof will be omitted, and different portions will be described below. To do.

(Second Embodiment)
7 to 9 show a second embodiment of the present invention. The second embodiment is different from the first embodiment in that the liquid introducing means is provided not on the piston 41 side but on the cylinder 21 side.

  That is, the rear surface 21b side portion of the cylinder 21 facing the tank chamber 53 is provided with a mounting recess 91 concentric with the second guide hole portion 22b and having a stepped hole having a diameter larger than the second guide hole portion 22b. A bush 92 that functions as introduction means is fitted and fixed. A gap S for absorbing variations in processing accuracy is provided between the front end surface 92a of the bush 92 and the inner surface 91a of the mounting recess 91. However, the gap S may be omitted. The inner diameter D of the bush 92 is the same as the hole diameter of the second guide hole portion 22b. The bush 92 is provided with a plurality of grooves 93 opened on the inner surface thereof, for example, at intervals of 90 °. These grooves 93 penetrate in the axial direction of the bush 92 and are open at both ends. One end opening communicates with the second guide hole portion 22b through the gap S, and the other end opening faces the tank chamber 53. .

  The end portion of the second shaft portion 43 of the piston 41 near the first shaft portion 42 is disposed so as to be supported by the bush 92 when the piston 41 is in the extended position. It is pushed into the second shaft portion 43 up to the position indicated by the middle two-dot chain line. In the state where the second shaft portion 43 is supported by the bush 92, the second guide hole portion 22b and the tank chamber 53 are communicated with each other via the groove 93, so that the chemical solution in the tank chamber 53 is transferred to the second shaft portion. 43 can be introduced. When the second shaft portion 43 passes through the gap S and is inserted into the second guide hole portion 22b, the pump chamber P is formed. Configurations other than those described above are the same as those in the first embodiment, including configurations not shown in FIGS.

  Therefore, even in the configuration of the second embodiment, the problem to be solved by the present invention can be solved by obtaining the same operation as that of the first embodiment. In the second embodiment, instead of omitting the bush 92, it is possible to provide grooves corresponding to a plurality of grooves on the back surface 21b side portion of the cylinder 21 facing the tank chamber 53.

(Third embodiment)
FIG. 10 shows a third embodiment of the present invention. In this embodiment, the concave portion 23 is formed deep in accordance with the movement stroke of the piston 41 to function as a storage portion and a reservoir chamber. Furthermore, the front surface 21a of the cylinder 21 is provided with a plurality of cut grooves 85 (only one is shown) for individually communicating the recess 23 and each communication hole 81. The communication hole 81 and the cut groove 85 form a liquid return portion. The cylinder cover 61 is a flat plate. Configurations other than those described above are the same as those in the first embodiment, including configurations not shown in FIG.

  Therefore, even in the configuration of the third embodiment, the problem to be solved by the present invention can be solved by obtaining the same operation as that of the first embodiment. Moreover, in the third embodiment, the configuration of the cylinder cover 61 can be simplified.

(Fourth embodiment)
A fourth embodiment of the present invention will be described. The liquid ejection device according to this embodiment is incorporated in, for example, an electronic device and used to circulate a cooling liquid that cools an electronic component that generates heat in the electronic device. In the following description, parts having the same configuration or function as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment.

  11A, 11B, and 12 includes a cylinder 21, a discharge valve 31, a piston 41, an external suction portion 25, a pumping member 51, and the like. ing.

  A cylinder 21 made of a material excellent in rust prevention and wear resistance, for example, metal, preferably stainless steel such as SUS304, has a cylinder body 121 and a cylinder cover 161 screwed thereto. Reference numeral 64 denotes a seal ring sandwiched between mating surfaces of the cylinder body 121 and the cylinder cover 161.

  The cylinder body 121 has a head sliding hole 121a having a circular cross section in a direction perpendicular to the axis thereof. The opening of the head sliding hole 121a is closed by a cylinder cover 161. The cylinder cover 161 is provided with a piston through hole 22 that passes through the cylinder cover 161 in the thickness direction and communicates with the head sliding hole 121a. The piston through hole 22 is a round hole having a smaller diameter than the head sliding hole 121a, and these axes coincide with each other. The head sliding hole 121 a and the piston through hole 22 form a cylinder hole of the cylinder 21.

  The piston 41 has a head 141 and a shaft portion 42 in which the head 141 is integrally formed at one end. The peripheral surfaces of the head 141 and the shaft portion 42 are made of a polished surface of a predetermined surface system that has been subjected to polishing, and it is not hindered to deposit a metal plating layer as necessary. The piston 41 and the cylinder 21 may be made of the same hardness material, preferably the same kind of metal material, in order to suppress mutual wear as much as possible. However, the piston 41 and the cylinder 21 are not limited to this, and the piston 41 and the cylinder 21 have the same hardness. It is also possible to use a hard synthetic resin. In addition, a metal plating layer having the same hardness as the other may be provided on one of the inner surface of the piston through hole 22 and the peripheral surface of the shaft portion 42 without using a material having the same hardness as the whole. .

  The head 141 has a circular shape, and the outer periphery thereof is slidably fitted into the inner periphery of the head sliding hole 121a. The head sliding hole 121a is partitioned into a pump chamber P and a suction chamber 121b by the head 141 accommodated in the head sliding hole 121a.

  The shaft portion 42 having a diameter smaller than that of the head 141 is a shaft portion having a circular cross section in a direction orthogonal to the axial direction, and passes through the piston through hole 22 and is supported by the through hole 22. As shown in FIG. 11B, the shaft portion 42 is slightly thinner than the piston through hole 22. Thereby, an annular fitting gap G is formed between the two for enabling liquid leakage. The fitting gap G communicates with the suction chamber 121b.

  The piston 41 is provided with, for example, a ball check valve 142 as a check valve that is responsible for communication between the suction chamber 121b and the pump chamber P and for disconnecting this communication. The check valve 142 has a conical valve seat surface 143a and a communication passage 143 provided between the suction chamber 121b and the pump chamber P, and is movably accommodated in the communication passage 143 so that the valve seat surface 143a. A ball 144 that forms a valve body that opens and closes the communication passage 143 by contacting and separating the ball and a valve body receiver 145 that allows the liquid to pass while preventing the ball 144 from coming off.

  A member presser 47 is attached to the tip of the shaft portion 42 that forms the other end of the piston 41 via a screw 48, and a screw 50 is attached via a holding plate 49 screwed to the member presser 47. It is mounted rotatably. A joint 3 a that is advanced and retracted by a drive mechanism (not shown) is screwed onto the screw 50. Therefore, the piston 41 is reciprocated relative to the cylinder 21 in the axial direction via the drive mechanism.

  The discharge valve 31 is a check valve that is responsible for communication between the pump chamber P and the outside of the cylinder 21 and for disconnecting the communication, and is screwed into a screw hole formed in the end wall of the cylinder body 121. The discharge valve 31 that communicates with the pump chamber P has a conical valve seat surface 131a and a communication passage 131 that communicates between the pump chamber P and the outside of the cylinder 21, and is movably accommodated in the communication passage 131. It has a ball 132 that forms a valve body that opens and closes the communication passage 131 by contacting and separating from the valve seat surface 131a, and a valve body receiver 133 that allows the liquid to pass while preventing the ball 132 from coming off.

  A discharge pipe (not shown) is connected to the discharge valve 31 and the liquid discharged through the pipe is led out to the outside. In the check valve 142 and the discharge valve 31, the balls forming the respective valve bodies may be biased toward the valve seat by a coil spring.

  The suction portion 25 communicates with the suction chamber 121b and is screwed into a screw hole formed in the peripheral wall of the cylinder body 121. A return pipe (not shown) is connected to the suction portion 25, and a liquid used for cooling an electronic component (not shown) is introduced into the suction chamber 121b through the pipe.

  The suction part 25 is provided close to the cylinder cover 161 and is away from the discharge valve 31. As a result, the pump chamber P and the suction chamber 121b partitioned by the head 141 of the piston 41 do not communicate with each other even when the piston 41 is pushed in the maximum, and the head 141 and the head in the same pushed-in state The dimension L1 between the sliding hole 121a and the back end face can be reduced without being restricted by the suction portion 25. In other words, the axial length of the cylinder 21 to which the suction portion 25 as a side port is attached can be shortened, and the liquid ejection device 3 can be reduced in size accordingly.

  Moreover, the check valve 142 that prevents the backflow of the liquid when the liquid in the pump chamber P is compressed is incorporated in the piston 41 and is not incorporated in the suction portion 25. Accordingly, the suction portion 25 does not need to have a large diameter sufficient to incorporate the check valve 142 therein, and the suction portion 25 only needs to have a small diameter. Therefore, the dimensions for attaching the suction portion 25 to the cylinder 21 can be shortened. Also in this respect, the axial length of the cylinder 21 to which the suction portion 25 that is a side port is attached can be shortened, and the liquid ejection device 3 can be downsized accordingly.

  The pumping member 51 is made of, for example, a cylindrical bellows having both ends opened. The pumping member 51 has liquid resistance and flexibility. An end 51 a on the large diameter side of the pumping member 51 is fitted in an annular groove 21 c provided in the cylinder cover 161, and is fixed in a liquid-tight manner to the cylinder 21 by an annular presser plate 52 screwed to the cylinder cover 161. Has been. An end 51 b on the small diameter side of the pumping member 51 is sandwiched between the other end of the piston 41 and the member presser 47, and is fixed to the other end of the piston 41 in a liquid-tight manner.

  As a result, the pumping member 51 is provided with a tank chamber 53 formed between the cylinder 21 and the cylinder cover 161, and is connected to the piston 41 so as to be able to deform following the reciprocating movement of the piston 41. ing. The tank chamber 53 is communicated with the fitting gap G. The volume of the tank chamber 53 which the pumping member 51 has is changed with the flexible deformation of the pumping member 51. The tank chamber 53 covers and hides the protruding portion of the piston 41 from the cylinder 21.

  The coolant discharge apparatus 300 having the above-described configuration is used as follows while maintaining the state in which the tank chamber 53 and the portion through which the liquid passes are filled with the liquid. 11A shows a non-operating state of the liquid ejection device 3, and FIG. 12 shows an operating state of the coolant ejection device 300.

  In a non-operating state, a driving mechanism (not shown) is in a standby state, and the pumping member 51 is held in an extended state. When the drive mechanism is operated, the piston 41 fitted into the cylinder 21 is pushed in, so that the pumping member 51 is flexibly deformed so as to shorten its length while expanding outward. As a result, the internal pressure of the tank chamber 53 is increased, and at the same time, the head 141 of the piston 41 is brought closer to the discharge valve 31 and the pump chamber P is contracted to increase its internal pressure, while the volume of the suction chamber 121b is increased. Then, the internal pressure decreases.

  As the pushing of the piston 41 proceeds, the check valve 142 of the piston 41 is closed and the internal pressure of the pump chamber P is further increased, so that the liquid filled in the pump chamber P pushes the discharge valve 31. The valve 31 is opened and discharged from the valve 31 to the outside. On the other hand, in the suction chamber 121b where the pressure decreases, the liquid recirculated to the suction portion 25 is sucked through the suction portion 25 and the liquid is stored in the tank chamber 53 pressurized by the pumping member 51. Part is fitted and sucked through gap G. The suction chamber 121b that receives the liquid returned through the fitting gap G in this manner functions as a reservoir chamber. The amount of liquid returned from the tank chamber 53 to the suction chamber 121b through the fitting gap G is small compared to the amount of liquid returning from the suction portion 25.

  The liquid discharge ends when the piston 41 is pushed in a predetermined stroke. Thereafter, the electric motor capable of rotating in the forward and reverse directions included in the drive mechanism (not shown) is rotated in the reverse direction, so that the piston 41 is pulled back to the drawing position shown in FIG. Such an operation is repeated at predetermined time intervals by a control device (not shown) at an appropriate time that requires cooling.

  As the piston 41 is pulled back to the drawing position from the state shown in FIG. 12, the head 141 is moved closer to the cylinder cover 161, the volume of the pump chamber P is expanded and the internal pressure is decreased, while the volume of the suction chamber 121b is decreased. As the internal pressure rises, the check valve 142 opens and the pump chamber P communicates with the suction chamber 121b. Therefore, the liquid in the suction chamber 121b is supplied to the pump chamber P through the communication path 143.

  At the same time, as the piston 41 is pulled back to the drawing position, the pumping member 51 is flexibly deformed so as to be extended, so that the internal pressure of the tank chamber 53 decreases. Therefore, a part of the liquid in the suction chamber 121 b having a high pressure flows into the tank chamber 53 through the fitting gap G and is stored in the tank chamber 53. Therefore, the liquid leaking from the fitting gap G with the reciprocating movement of the piston 41 does not leak to the outside of the coolant discharge device 300.

  As described above, the coolant discharge device 300 that discharges in consideration of the liquid leakage between the piston through hole 22 and the shaft portion 42 of the piston 41 is elastically and strongly in contact with the inner surface of the piston through hole 22. A small amount of liquid controlled to be a predetermined amount can be discharged from the pump chamber P through the discharge valve 31 without using a seal ring. Thus, unlike the configuration using the seal ring that is elastically strongly rubbed against the inner surface of the piston through-hole 22, there is no change in the discharge amount due to wear of the seal ring. In addition, wear due to the sliding of the piston 41 with respect to the piston through hole 22 can be suppressed by the liquid leaking from the fitting gap G between them. Therefore, the change in the discharge amount based on the wear during long-term use is suppressed, and stable quantitative discharge performance can be maintained over a long period of time.

  At the same time, there is no friction loss between the piston through-hole 22 and the piston 41 as compared with a configuration using a seal ring that is elastically strongly and rubbed against the inner surface of the piston through-hole 22. For this reason, the driving force of the piston 41 can be reduced, and an electric motor having a smaller torque and hence smaller size can be used for the electric motor of the driving mechanism.

  In the above-described operation, the piston 41 is supported at one end in the axial direction by the head sliding hole 121a and supported at the piston through hole 22 at the shaft portion 42 at the intermediate portion in the axial direction. Thereby, there is no fear that the piston 41 will wobble, and the reciprocating movement along the axial direction can be performed stably, so that the quantitative discharge operation is smooth.

(Fifth embodiment)
A fifth embodiment of the present invention shown in FIGS. 13A and 13B will be described. Since the coolant discharge apparatus 300 according to this embodiment is basically the same as that of the fourth embodiment, the same portions are denoted by the same reference numerals as those of the fourth embodiment, and description of the configuration and operation thereof is omitted. In the following, different parts will be described.

  In this fifth embodiment, the piston through hole 22 is made non-circular, and due to the relationship with the shaft part 42 having a circular cross section passing through the piston hole 22, there is no liquid between the shaft part 42 and the piston through hole 22. A fitting gap G for leaking is formed. Specifically, the piston passage hole 22 has a plurality of liquid passage grooves 122 extending along the axial direction of the piston 41. As shown in FIG. 13B, the liquid passage groove 122 divides the inner surface of the piston passage hole 22 into a plurality of regions. The configuration other than the points described above is the same as that of the fourth embodiment.

  Therefore, also in the configuration of the fifth embodiment, the same effect as that of the fourth embodiment can be obtained to solve the problem of the present invention. Moreover, by providing the liquid passage groove 122, it extends between the suction chamber 121 b that functions as a reservoir chamber whose volume expands and contracts as the piston 41 reciprocates, and the tank chamber 53 inside the pumping member 51. The liquid can be more smoothly distributed through the gap G. For this reason, it is excellent in that the expansion and contraction operation of the pumping member 51 becomes smooth and the driving force of the piston 41 can be further reduced.

(Sixth embodiment)
A sixth embodiment of the present invention shown in FIG. 14 will be described. Since the coolant discharge apparatus 300 according to this embodiment is basically the same as that of the fourth embodiment, the same portions are denoted by the same reference numerals as those of the fourth embodiment, and description of the configuration and operation thereof is omitted. In the following, different parts will be described.

  In the sixth embodiment, a reservoir tank 111 communicating with the tank chamber 53 is provided, and a reservoir path is provided for this communication.

  That is, the passage 112 is provided in the cylinder cover 161. One end of the passage 112 opens into the tank chamber 53, and a pipe joint 113 that protrudes outside the cylinder cover 161 is connected to the other end. Further, a pipe joint 114 is connected to a reservoir tank 111 that is installed away from the cylinder 21 and a pipe 115 is connected across the pipe joints 113 and 114. One of the pipe joints 113, 114, for example, the pipe joint 113 also serves as a throttle for narrowing the flow path. It is desirable that the flow path resistance at this restriction is smaller than the flow path resistance at the fitting gap G. The configuration other than the points described above is the same as that of the fourth embodiment.

  Therefore, also in the configuration of the sixth embodiment, the same effect as that of the fourth embodiment can be obtained to solve the problem of the present invention. In addition, by providing the reservoir tank 111, when the piston 41 is pushed in and the liquid in the tank chamber 53 is compressed, the liquid is transferred from the tank chamber 53 to the reservoir tank 111 through the reservoir path when the pressure exceeds the predetermined pressure. Since the pressure can be released with the outflow, the driving force required for the pushing force of the piston 41 can be reduced.

(Seventh embodiment)
A seventh embodiment of the present invention shown in FIGS. 15 and 16 will be described. Since the coolant discharge apparatus 300 according to this embodiment is basically the same as that of the fourth embodiment, the same portions are denoted by the same reference numerals as those of the fourth embodiment, and description of the configuration and operation thereof is omitted. In the following, different parts will be described.

  In the seventh embodiment, the reservoir 201 is liquid-tightly connected to the cylinder cover 161 of the cylinder 21. The reservoir 201 has a reservoir chamber R formed therein, and the reservoir chamber R communicates with the suction chamber 121b through a fitting gap G. As already described in the seventh embodiment, the piston 41 is provided with the communication between the suction chamber 121b and the pump chamber P and the check valve 142 that cuts off this communication.

  The reservoir 201 has a through hole 202. The shaft portion 42 of the piston 41 is passed through the through hole 202. The shaft portion 42 is slightly narrower than the through hole 202, and an annular fitting gap g that allows the liquid to flow therethrough is formed between them.

  An end 51 a of a pumping member 51 that finally contains the leaked liquid is fixed to the reservoir 201 by a presser plate 52 screwed to the reservoir 201. The pumping member 51 is formed in a bellows shape by, for example, a chemical resistant material, has flexibility and stretchability, and both ends thereof have, for example, the same diameter. An end 51 b of the pumping member 51 is fixed to a receiving plate 47 a sandwiched between them by a member presser 47 that is screwed to the holding plate 49. The inner side 53a of the pumping member 51 communicates with the reservoir chamber R through the fitting gap g. Therefore, in the sixth embodiment, the reservoir chamber R and the inner side 53a of the pumping member 51 function as a tank chamber that receives liquid leakage. However, the reservoir chamber R that mainly receives liquid leakage is not related to the pumping member 51 but the reservoir 201. Therefore, the substantial tank chamber and the pumping member 51 are provided separately. The screw 48 is connected to the shaft portion 42 through the receiving plate 47a. The configuration other than the points described above is the same as that of the fourth embodiment.

  Therefore, also in the configuration of the seventh embodiment, the same effect as that of the fourth embodiment can be obtained to solve the problem of the present invention. In this case, a seal ring is not used between the through hole 202 of the reservoir 201 and the shaft portion 42 of the piston 41 penetrating the reservoir 201, and a small amount is passed through the fitting gap g between the through hole 202 and the shaft portion 42. Since the liquid is leaked, the driving force required for the reciprocating motion of the piston 41 can be reduced as in the fourth embodiment.

(Eighth embodiment)
An eighth embodiment of the present invention shown in FIGS. 17 and 18 will be described. Since the coolant discharge apparatus 300 according to this embodiment is basically the same as that of the fourth embodiment, the same portions are denoted by the same reference numerals as those of the fourth embodiment, and description of the configuration and operation thereof is omitted. In the following, different parts will be described.

  In the eighth embodiment, a fitting gap G1 that allows leakage between the pump chamber P and the suction chamber 121b is provided between the head sliding hole 121a of the cylinder 121 and the head 141 of the piston 41. The fitting gap G1 is formed between the piston through hole 22 of the cylinder cover 161 and the shaft portion 42 of the piston 41, and has the same width as the fitting gap G that allows leakage between the suction chamber 121b and the tank chamber 53. However, it is also possible to make it narrower than the fitting gap G. When the fitting gap G1 is narrower than the fitting gap G, it is preferable in that the liquid can be easily discharged at a predetermined pressure when the piston 41 is pushed. The configuration other than the points described above is the same as that of the fourth embodiment.

  Therefore, also in the configuration of the eighth embodiment, the same effect as that of the fourth embodiment can be obtained to solve the problem of the present invention.

  In addition, compared with the sliding area between the cylinder through hole 22 and the shaft portion 42 that slidably passes therethrough, the space between the head sliding hole 121a and the head 141 slidably inserted in the head sliding hole 121a. Although the sliding area is large, the sliding resistance at the latter sliding portion can be reduced by the fitting gap G1. For this reason, it is preferable in that the driving force of the coolant discharge device 300 can be further reduced as the piston 41 with respect to the cylinder 121 can slide easily.

(Ninth embodiment)
A ninth embodiment of the present invention shown in FIGS. 19 and 20 will be described. Since the coolant discharge apparatus 300 according to this embodiment is basically the same as that of the eighth embodiment, the same portions are denoted by the same reference numerals as those of the eighth embodiment, and description of the configuration and operation thereof is omitted. In the following, different parts will be described.

  In the ninth embodiment, the suction portion 25 is provided facing the pump chamber P toward the discharge valve 31 and away from the cylinder cover 161. A check valve 142 is incorporated in the suction portion 25 communicating with the pump chamber P, and the communication path and the check valve are not provided in the piston 41 correspondingly. The check valve 142 opens when the pump chamber P becomes low pressure and closes when the pressure becomes high. When the piston 41 is moved in the drawing direction and the pump chamber P becomes a low pressure, the liquid is directly sucked from the suction portion 25. For this reason, the pump chamber P also serves as a suction chamber. The configuration other than the points described above is the same as that of the eighth embodiment.

  Therefore, also in the configuration of the ninth embodiment, the same effect as that of the eighth embodiment can be obtained to solve the problem of the present invention.

  In addition, since the check valve 142 is provided in the suction portion 25 and not in the piston 41, the processing and configuration of the piston 41 are simplified, the cost can be reduced, and the diameter of the piston 41 and the cylinder 21 is reduced. This is advantageous because the check valve 142 is not a restriction.

(10th Embodiment)
A tenth embodiment of the present invention shown in FIGS. 21 and 22 will be described. Since the coolant discharge apparatus 300 according to this embodiment is basically the same as that of the ninth embodiment, the same parts are denoted by the same reference numerals as those of the ninth embodiment, and description of the configuration and operation thereof is omitted. In the following, different parts will be described.

  In the tenth embodiment, the cylinder 21 does not include a cylinder cover. Therefore, only a fitting gap G1 that allows leakage due to pumping is provided between the head 141 of the piston 41 and the head sliding hole 121a, and a fitting gap is provided around the shaft portion 42. Not. An end 51a on the large-diameter portion side of the pumping member 51 is fitted into an annular groove 21c provided on the back surface 21b of the cylinder 21, and is fixed to the cylinder 21 with an annular presser plate 52 screwed to the back surface 21b. Has been. Therefore, the back surface of the head 141 of the piston 41 slidably inserted into the head sliding hole 121a of the cylinder 21 and the inner surface of the pumping member 51 are opposed to each other. The configuration other than the points described above is the same as that of the ninth embodiment.

  Therefore, also in the configuration of the tenth embodiment, the same effect as that of the ninth embodiment can be obtained to solve the problem of the present invention.

  Moreover, since the cylinder 21 is not provided with a cylinder cover, the axial length of the coolant discharge device 300 is shortened by an amount corresponding to the thickness of the cylinder cover, so that the coolant discharge device 300 can be reduced in size and the number of parts can be reduced. This simplifies the configuration and reduces costs. Further, the coolant discharge apparatus 300 according to the tenth embodiment can be suitably used as a means for ensuring a predetermined discharge flow rate with a light discharge pressure.

(Eleventh embodiment)
An eleventh embodiment of the present invention shown in FIG. 23 will be described. Since the coolant discharge apparatus 300 according to this embodiment is basically the same as that of the fourth embodiment, the same portions are denoted by the same reference numerals as those of the fourth embodiment, and description of the configuration and operation thereof is omitted. In the following, different parts will be described.

  The liquid ejection device 3 according to the eleventh embodiment includes, for example, a coil spring 301 as an urging body that urges the piston 41 in a direction to push back the piston 41 during the ejection process. For example, a compression coil spring is used as the coil spring 301. The coil spring 301 is built in the liquid ejection device 3 and is sandwiched between, for example, the head 141 of the piston 41 and the cylinder cover 161 facing the back surface. As the piston 41 is pushed into the cylinder 121 while compressing and deforming the bellows pumping member 51, the coil spring 301 reduces the spring force and gives a pushing back force to the piston 41. The configuration other than the points described above is the same as that of the fourth embodiment.

  Therefore, also in the configuration of the eleventh embodiment, the same effect as that of the fourth embodiment can be obtained to solve the problem of the present invention.

  Moreover, having the coil spring 301 is preferable in the following points. That is, in the discharging step, the bellows pumping member 51 is compressed and deformed, so that the restoring force for the pumping member 51 to return to the original state gradually increases. This restoring force becomes a load with respect to the driving force of the liquid ejection device 3. However, as described above, the spring force of the coil spring 301 that decreases as the piston 41 is pushed into the cylinder 121 is given to the piston 41 as a pushing-back force in the same direction as the pulling-out direction of the piston 41 by the drive unit. This pushing back force can reduce the load. Thereby, the driving force of the liquid ejection device 3 can be further reduced.

  Note that the use of a compression coil spring as the coil spring 301 has an advantage of good assembly, but instead, a tension coil spring is sandwiched between, for example, the head 141 of the piston 41 and the cylinder cover 161 facing the back surface. It is also possible to set up. In this case, as the piston 41 is pushed into the cylinder 121 while compressing and deforming the bellows pumping member 51, the tension coil spring 301 increases the spring force. It is excellent in the point that can be given.

(Twelfth embodiment)
A twelfth embodiment of the present invention shown in FIG. 24 will be described. Since the coolant discharge apparatus 300 according to this embodiment is basically the same as that of the eleventh embodiment, the same portions are denoted by the same reference numerals as those of the eleventh embodiment, and description of the configuration and operation thereof is omitted. In the following, different parts will be described.

  In the coolant discharge apparatus 300 of the twelfth embodiment, for example, a coil spring 301 as an urging member that urges the piston 41 back in the discharge process is externally attached to the coolant discharge apparatus 300, for example, a joint 3a. And a fixing member 302 opposite to this. As the coil spring 301, either a compression coil spring or a tension coil spring can be used. The configuration other than the points described above is the same as that of the eleventh embodiment.

  Therefore, even in the configuration of the twelfth embodiment, the same effect as that of the eleventh embodiment can be obtained to solve the problem of the present invention.

  In addition, the liquid discharge apparatus of the present invention can be applied to uses other than the above-described chemical liquid injection or cooling liquid circulation.

The figure which shows the structure of the chemical | medical solution injection | pouring unit provided with the chemical | medical solution discharge apparatus which concerns on 1st Embodiment of this invention. Sectional drawing which shows the chemical | medical solution discharge apparatus which concerns on 1st Embodiment. Sectional drawing which shows the chemical | medical solution discharge apparatus of a piston drawing-out state along the ZZ line in FIG. Sectional drawing which shows the chemical | medical solution discharge apparatus of a piston pushing state along the ZZ line in FIG. FIG. 3 is a side view showing a part of the chemical liquid ejection device in a piston pulled-out state along a line YY in FIG. 2. FIG. 3 is a perspective view showing a cross section of a part of the chemical liquid ejection device in FIG. 2. Sectional drawing which shows the chemical | medical solution discharge apparatus which concerns on 2nd Embodiment of this invention in a piston drawing-out state. Sectional drawing which shows a part of chemical | medical solution discharge apparatus of FIG. Sectional drawing which follows the XX line in FIG. Sectional drawing which shows the chemical | medical solution discharge apparatus which concerns on 3rd Embodiment of this invention in a piston drawing-out state. (A) is sectional drawing which shows the cooling fluid discharge apparatus which concerns on 4th Embodiment of this invention in a piston drawer | drawing-out state. (B) is sectional drawing which follows the WW line in FIG. 11 (A). Sectional drawing which shows the coolant discharge apparatus of FIG. 11 (A) in a piston pushing state. (A) is sectional drawing which shows the cooling fluid discharge apparatus which concerns on 5th Embodiment of this invention in a piston drawing-out state. (B) is sectional drawing which follows the VV line in FIG. 13 (A). Sectional drawing which shows the cooling-liquid discharge apparatus which concerns on 6th Embodiment of this invention in a piston drawing-out state. Sectional drawing which shows the cooling-liquid discharge apparatus which concerns on 7th Embodiment of this invention in a piston drawing-out state. Sectional drawing which shows the cooling fluid discharge apparatus which concerns on 7th Embodiment in piston pushing state. (A) is sectional drawing which shows the cooling fluid discharge apparatus which concerns on 8th Embodiment of this invention in a piston drawing-out state. (B) is sectional drawing which follows the TT line | wire in FIG. 17 (A). (C) is sectional drawing which follows the SS line | wire in FIG. 17 (A). Sectional drawing which shows the coolant discharge apparatus which concerns on 8th Embodiment of this invention in a piston pushing state. (A) is sectional drawing which shows the cooling fluid discharge apparatus which concerns on 9th Embodiment of this invention in a piston drawing-out state. (B) is sectional drawing which follows the RR line | wire in FIG. 19 (A). (C) is sectional drawing which follows the QQ line in FIG. 19 (A). Sectional drawing which shows the cooling fluid discharge apparatus which concerns on 9th Embodiment of this invention in a piston pushing state. (A) is sectional drawing which shows the cooling fluid discharge apparatus which concerns on 10th Embodiment of this invention in a piston drawer | drawing-out state. (B) is sectional drawing which follows the PP line in FIG. 20 (A). A sectional view showing a cooling fluid discharge device concerning a 10th embodiment of the present invention in a piston pushing state. Sectional drawing which shows the cooling fluid discharge apparatus which concerns on 11th Embodiment of this invention in a piston drawing-out state. A sectional view showing a cooling fluid discharge device concerning a 12th embodiment of the present invention in a piston drawer state.

Explanation of symbols

3 ... Chemical liquid discharge device (liquid discharge device)
DESCRIPTION OF SYMBOLS 21 ... Cylinder 22 ... Piston through-hole 22a ... 1st guide hole part 22b ... 2nd guide hole part 23 ... Recessed part (liquid return part)
DESCRIPTION OF SYMBOLS 25 ... Suction part 27 ... Discharge flow path 27a ... Inlet part 27b ... Conical valve seat part 27c ... Circular hole part 31 ... Discharge valve 32 ... Valve body 32a ... Valve main body 32ah ... Conical end part 32b ... Rib 33 ... Coil spring DESCRIPTION OF SYMBOLS 41 ... Piston 42 ... 1st axial part 43 ... 2nd axial part P ... Pump chamber 51 ... Pumping member 53 ... Tank chamber 61 ... Cylinder cover 62 ... Reservoir chamber 63 ... Escape recessed part 71 ... Groove (liquid introduction means)
81. Communication hole (liquid return part)
85 ... notch groove (liquid return part)
92 ... Bush (liquid introducing means)
93 ... Bush groove (liquid introducing means)
DESCRIPTION OF SYMBOLS 111 ... Reservoir tank 121 ... Cylinder body 121a ... Head sliding hole 121b ... Suction chamber 141 ... Head 161 ... Cylinder cover G ... Fitting gap G1 ... Fitting gap 201 ... Reservoir R ... Reservoir chamber g ... Fitting gap 300 ... Cooling Liquid discharge device (liquid discharge device)
301 ... Coil spring (biasing body)

Claims (17)

A liquid discharge device that discharges, through a discharge valve, a liquid that is sucked through a suction portion and filled in a pump chamber by a pushing operation of a piston with respect to a cylinder,
A pumping member configured to leak from a fitting gap between the cylinder and the piston, and to have a tank chamber for receiving liquid leaking from the fitting gap, and to be deformed following the reciprocating movement of the piston; Liquid discharge device connected to the cylinder. A liquid discharge device that discharges, through a discharge valve, a liquid that is sucked through a suction portion and filled in a pump chamber by a pushing operation of a piston with respect to a cylinder,
The cylinder includes a cylinder body having a head sliding hole, and a cylinder cover having a piston through hole communicating with the head sliding hole and connected to the cylinder body.
The piston divides the inside of the head sliding hole into the pump chamber communicating with the discharge valve and the suction chamber communicating with the suction portion, and a head that can slide the head sliding hole, and is continuous with the head. A shaft portion slidably passed through the piston through hole,
Among the fitting clearance between the head sliding hole and the head and the fitting clearance between the piston through-hole and the shaft portion, at least the latter fitting clearance is allowed to leak along with the pushing operation of the piston. ,
A liquid ejecting apparatus having a tank chamber for receiving liquid leaking from the latter fitting gap and having a pumping member which is deformed following the reciprocating movement of the piston connected to the cylinder. A liquid discharge device that discharges, through a discharge valve, a liquid that is sucked through a suction portion and filled in a pump chamber by a pushing operation of a piston with respect to a cylinder,
The cylinder has a piston hole;
The piston shaft is slidably supported by the piston through hole, and the piston is inserted into the piston through hole and the piston is allowed to leak from the fitting gap.
A reservoir forming a reservoir chamber for receiving liquid leaking from the fitting gap is connected to the cylinder;
A liquid discharge apparatus having a tank chamber in communication with the reservoir chamber on the inside and a pumping member deformed following the reciprocating movement of the piston connected to the reservoir.   The liquid ejection device according to claim 2 or 3, wherein the fitting gap is formed between the piston through hole and the shaft portion having a circular cross section formed narrower than the piston through hole.   The inside of the hole which the said piston through-hole has the fluid passage groove | channel extended along the axial direction of the said piston, and supports the said piston by this fluid passage groove | channel is divided into the some area | region. The liquid discharge apparatus according to any one of the above. A liquid discharge device that discharges, through a discharge valve, a liquid that is sucked through a suction portion and filled in a pump chamber by a pushing operation of a piston with respect to a cylinder,
Leakage from the fitting gap between the cylinder head sliding hole and the piston head,
A pumping member that has a tank chamber that receives liquid leaking from the fitting gap inside and is deformed following the reciprocating movement of the piston is connected to the cylinder,
Providing the suction part in communication with the pump chamber;
A liquid discharge device provided with a check valve in the suction portion that opens when the pump chamber becomes low pressure and closes when the pressure becomes high.   The liquid discharging apparatus according to claim 1, wherein the pumping member is a bellows.   The liquid ejecting apparatus according to claim 7, further comprising a biasing body that biases the bellows in a direction extending in an axial direction thereof.   The liquid discharge apparatus according to claim 1, further comprising a reservoir tank communicating with the tank chamber. A liquid discharge device that discharges, through a discharge valve, a liquid that is sucked through a suction portion and filled in a pump chamber by a pushing operation of a piston with respect to a cylinder,
The piston is slidably supported in the piston through hole of the cylinder, and the piston is leaked from the fitting clearance between the piston through hole and the piston in accordance with the pushing operation of the piston.
A reservoir chamber for receiving this liquid,
A tank that communicates with the reservoir chamber through the liquid return portion, changes in volume following the reciprocating movement of the piston, and stores the liquid supplied to the pump chamber by suction from the suction portion due to the volume change. Room,
A liquid ejection device comprising: A liquid discharge device that discharges, through a discharge valve, a liquid that is sucked through a suction portion and filled in a pump chamber by a pushing operation of a piston with respect to a cylinder,
A piston through hole having a second guide hole portion communicating with the first guide hole portion and a discharge flow path having a larger cross section than the first guide hole portion and disposed with the discharge valve is provided therethrough, The cylinder having a cylinder cover forming a reservoir chamber;
A first shaft portion guided by the first guide hole portion, and a second section having a larger cross section than the first shaft portion and inserted into and removed from the second guide hole portion and guided in the second guide hole portion in the inserted state. The piston having a shaft portion and penetrated through the piston through hole so as to reciprocate;
A pumping member that has a tank chamber for storing the liquid sucked through the suction portion inside and is deformed following the reciprocating movement of the piston and changes the volume of the tank chamber by the deformation;
Liquid introduction means for communicating the tank chamber and the second guide hole when the piston is disposed at a position where the second shaft is pulled out from the second guide hole;
A liquid return portion communicating the reservoir chamber and the tank chamber communicating with the fitting gap between the first guide hole portion and the first shaft portion;
A liquid ejection apparatus comprising:   The liquid ejection device according to claim 10 or 11, wherein the liquid return portion includes a communication hole penetrating the cylinder.   The liquid ejecting apparatus according to claim 10, wherein the cylinder and the piston are made of a material having the same hardness.   The liquid introducing means is a groove that extends in the axial direction in a circumferential portion between the first shaft portion and the second shaft portion of the piston, and the groove is opened to the circumferential surface of the piston. 14. The liquid ejection device according to claim 11, wherein the liquid ejection device is open toward the first shaft portion.   A cross section of the first guide hole portion and a cross section of the first shaft portion are each circular, and a cross section of the second guide hole portion is larger than a cross section of the first guide hole portion, and the second shaft portion. The cross section of the pump chamber is larger than the cross section of the first shaft portion, and the pump chamber closed by the second shaft portion when the piston is pushed in includes the second guide hole portion and the first shaft portion. The liquid ejecting apparatus according to claim 11, wherein the liquid ejecting apparatus is formed between the liquid ejecting apparatus and the liquid ejecting apparatus.   The liquid discharging apparatus according to claim 11, wherein the pumping member is a bellows.   The discharge flow path has a conical valve seat portion and a circular hole continuous to the downstream side of the valve seat portion, and the discharge valve has a conical end portion that contacts and separates from the conical valve seat portion. 15. The valve body according to claim 11, further comprising: a valve body including a valve body having a plurality of ribs protruding from a peripheral surface of the valve body and slidingly contacting the circular hole portion. Liquid discharge device.

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