JP2006104965A - Liquid delivery device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid delivery device, lightly drivable, and capable of preventing liquid leakage to an external part with a simple constitution. <P>SOLUTION: A pump 10 is operated by a driving mechanism composed of a motor part 50 and a transmission part 60, and delivers liquid sucked via a suction part 28 and filled in a pump room P via a delivery valve 11a by pushing-in operation of a piston 31. The pump 10 has a cylinder 11, the piston 31, and a cylindrical pumping member 41 deformed by following reciprocating motion of the piston. The piston 31 is arranged so as to leak the liquid from clearance G with this cylinder by fitting to the cylinder 11. First and second flanges 42 and 43 are arranged in its both end parts by molding a member 41 by an elastic material, and a tank room 47 is arranged inside this member 41 for storing the liquid leaked from the clearance G. The flange 42 is liquidtightly sandwiched by the cylinder 11 and a first pressing member 46 connected to this cylinder, and the flange 43 is liquidtightly sandwiched by the piston 31 and a second pressing member 39 connected to this piston. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fixed volume discharge type liquid discharge device, for example, injecting a chemical solution into a living body in a fixed amount or quantifying a liquid that is built in various devices having electronic components that generate heat and cools the heat generating components. The present invention relates to a liquid ejecting apparatus that can be used to send out liquids one by one, and an electronic apparatus including the liquid ejecting apparatus.

  Conventionally, a liquid discharging apparatus 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 inserted 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. As this seal ring, an O-ring capable of elastic deformation such as an elastomer is usually used.
Japanese Patent Laid-Open No. 2001-315713 (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 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 this case, the stronger the close contact 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 is more likely to proceed.

  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. Therefore, a drive mechanism that drives the pump needs to generate a large drive energy.

  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, the plunger pump described in Patent Document 1 is likely to change its discharge characteristics due to the liquid leakage. Therefore, further ingenuity is required to enable continuous use over a long period of time. 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 discharge device and an electronic apparatus that can be driven lightly and can prevent liquid leakage to the outside with a simple configuration.

  In order to solve the above problems, a liquid discharge apparatus according to the present invention includes a pump and a drive mechanism for operating the pump, and is sucked through a suction portion by a piston pushing operation with respect to a cylinder of the pump. A liquid discharge device for discharging a liquid filled in the piston, wherein the pump is provided so as to leak from the cylinder and a gap between the cylinder and the cylinder. The first flange and the second flange are individually formed at both ends and formed of an elastic material, and the first presser member connected to the cylinder and the cylinder are used to make the first flange liquid. The second flange is tightly sealed with the piston and the second presser member connected thereto, and the liquid leaking from the gap is accommodated inside. Forming a ink chamber and a tubular pumping member that is extendable to follow the reciprocating movement of the piston.

  In the present invention, with the reciprocation of the piston, a slight amount of liquid can be leaked from the cylinder to the tank chamber side formed inside the pumping member with the gap between the cylinder and the piston as a flow path. Since the flow rate passing through the gap, that is, the leakage amount can be defined by the dimensional accuracy of the piston and the piston, it can be controlled to be very small by increasing the dimensional system. Liquid enters and exits the tank chamber as the pumping member expands and contracts following the reciprocating movement of the piston. For this reason, as the piston reciprocates, the liquid leaking from the gap is accommodated in the tank chamber, and the liquid is eventually sucked into the pump chamber and discharged from the pump chamber. Thus, in the liquid discharge device of the present invention, since the cylinder does not have a seal ring that is elastically strong and rubbed against the cylinder, the driving force of the piston can be small.

  Liquid leakage to the outside of the tank chamber is prevented by a cylindrical pumping member that expands and contracts following the reciprocating movement of the piston. In this case, the flange itself can function as a seal material by connecting the both ends of the pumping member to the cylinder and the piston with the flanges at both ends of the pumping member made of an elastic material interposed therebetween. For this reason, liquid leakage to the outside of the tank chamber can be prevented with a simple configuration without requiring a special sealing member.

  In a preferred embodiment of the present invention, the first flange protrudes outside the pumping member, the second flange protrudes inside the pumping member, and the second flange is connected to the pumping member. An annular flange pressing portion provided on the piston and the second pressing member connected to the piston are closely attached.

  In the present invention, since the second flange has a smaller diameter than the first flange, the first flange is attached to the cylinder using the first presser member, and the piston using the second presser member is used. The mounting of the second flange is preferable in terms of mounting work of the pumping member in that it can be performed from the same direction toward the cylinder side.

  In a preferred embodiment of the present invention, an annular convex portion that is in close contact with the cylinder is provided integrally with the first flange, and an annular convex portion that is in close contact with the second pressing member is integrally formed with the second flange. Provided.

  In the present invention, as the first pressing member is connected to the cylinder, the connecting force is concentrated on the annular convex portion of the first flange sandwiched between the first pressing member and the convex portion is brought into close contact with the cylinder. As the second presser member is connected to the piston, the connecting force is concentrated on the annular convex portion of the second flange sandwiched between the presser member and the flange presser portion of the piston. The convex portion can be brought into close contact with the second pressing member. This is preferable in that the liquid tightness of the tank chamber can be improved.

  In a preferred embodiment of the present invention, the drive mechanism has an output gear and an electric motor that rotates the gear, and the output gear is arranged in a direction in which the pumping member extends to be arranged on the side of the pump. A motor unit, a drive member connected to the second pressing member and reciprocatingly moved in the axial direction of the piston, and a motion converting unit for converting the rotation of the output gear into the reciprocating movement of the drive member. And a transmission unit disposed across the motor unit and the pump.

  In this invention, since the motor part and the pump are connected by the transmission part arranged over them, the motor part is not continuously arranged in the axial direction with respect to the pump. As a result, a liquid discharge device having a compact configuration with a short overall length can be obtained.

  In a preferred embodiment of the present invention, the second pressing member has a protruding portion protruding outward with respect to the outer periphery of the second flange, and the driving member is fitted into the protruding portion to The pump and the transmission unit are connected.

  In the present invention, as described above, the second flange has a smaller diameter than the first flange, and the drive member is provided in the protruding portion of the second pressing member that protrudes from the outer periphery thereof. The distance between the drive member and the piston is short. For this reason, it is suppressed that the length of a transmission part becomes large in the direction where a pump and a motor part were located in a line, and it can contribute to size reduction of a liquid discharge apparatus.

  Moreover, in the preferable form of this invention, each of the said pump, a motor part, and a transmission part is made into the unit. In the present invention, since the entire apparatus can be assembled in a state where the pump, the motor unit, and the transmission unit are each a unit in advance, it is preferable in that the assembly workability can be improved.

  In order to solve the above-mentioned problems, an electronic apparatus according to the present invention incorporates the liquid discharge device according to claim 6. In this electronic device, for example, a liquid discharge device used for sending out a liquid for cooling a heat generating electronic component such as a CPU in a fixed amount is incorporated in the main body of the electronic device. Since the liquid discharge device can be assembled in a state where the pump, the motor portion, and the transmission portion constituting the liquid discharge device are each in advance as a unit, the assembly workability is good and the assembly is possible. In addition, it is preferable in that the liquid discharge device can be easily incorporated into the apparatus main body.

  According to the present invention, since a seal ring that is elastically intimately rubbed against the cylinder is not used, the tank chamber can be driven lightly and can store the liquid leaking from the gap between the cylinder and the piston. Since the tank chamber is sealed using a pumping member formed on the inside, a liquid discharge device capable of preventing liquid leakage to the outside with a simple configuration, and an electronic apparatus including the liquid discharge device are provided. it can.

  An embodiment of the present invention will be described with reference to FIGS. The liquid discharging apparatus according to this embodiment is used as a cooling liquid discharging apparatus 1 that is incorporated in, for example, an electronic device and circulates a cooling liquid that cools an electronic component that generates heat in the electronic device. An electronic component cooling device (not shown) provided with the cooling liquid discharging device 1 includes a heat receiving portion that transmits heat from an electronic component (heating element) that generates heat to a liquid, a heat radiating portion that releases heat from the liquid to the outside, A cooling liquid discharge device 1 that moves the liquid and a flow path that circulates the liquid over the heat receiving portion, the heat radiating portion, and the cooling liquid discharge device 1 are provided.

  As shown in FIGS. 3, 4, 6, etc., the coolant discharge device 1 is formed by assembling a pump 10, a motor unit 50, and a transmission unit 60 that are unitized. The coolant discharge device 1 is ultra-compact, for example, the x (vertical) dimension shown in FIG. 1 is 15 mm, the Y (horizontal) dimension shown in FIG. 2 is 10 mm, and the z (depth) shown in FIG. The dimension is 5mm. The motor unit 50 and the transmission unit 60 form a drive mechanism that drives the pump 10. The pump 10 and the motor unit 50 are disposed in the projection region of the transmission unit 60 except for the suction unit 28 described later.

  The pump 10 includes a cylinder 11 with a discharge valve 11a, an external suction portion 28, a piston 31, a pumping member 41, and the like.

  As shown in FIGS. 4 to 7, the cylinder 11 includes a cylinder body 12 and a cylinder head 13 made of a material excellent in rust prevention and wear resistance, for example, a metal material such as SUS304, and fixed parts such as a plurality of screws. 14 (see FIG. 2 and FIG. 5). The cylinder body 12 has a head sliding hole 12 a having a circular cross section in a direction perpendicular to the axis thereof, and the open end of the sliding hole 12 a is covered with the cylinder head 13.

  At the center of the back wall 12b of the cylinder body 12, a guide cylinder 15 integrated therewith projects from the head sliding hole 12a on the opposite side of the cylinder head 13. The guide cylinder portion 15 having a circular outer peripheral surface has a piston through hole 15a penetrating in the axial direction and at least one, for example, a plurality of liquid through holes 15b. Each liquid passage hole 15b is provided so as to penetrate the guide tube portion 15 in the axial direction. These liquid passage holes 15b are provided in communication with the piston through hole 15a in this embodiment, but may not be in communication. The piston through hole 15a and each liquid through hole 15b communicate with the head sliding hole 12a. Note that the guide cylinder portion 15 is preferable for suppressing the later-described inclination of the piston with respect to the axis of the cylinder body 12 and smoothing the axial movement of the piston. However, the guide tube portion 15 can be omitted, and in this case, the piston passage hole 15a and at least one liquid passage hole 15b may be provided in the rear wall 12b.

  A flange set groove 16 is provided in the back wall 12 b of the cylinder body 12. The flange set groove 16 has a larger diameter than the guide tube portion 15 and has an annular shape concentric with the guide tube portion 15, and is provided so as to surround the root portion of the guide tube portion 15 in the present embodiment. As shown in FIG. 5, the outer peripheral shape of the cylinder body 12 is a quadrangular shape, and a suction portion 28 forming a side port is screwed onto one side wall of the cylinder body 12. A plurality of positioning holes 17 and 18 are provided on the other side wall parallel to the one side wall.

  The suction portion 28 is provided for introducing a circulating cooling liquid into a suction chamber S described later. As shown in FIG. 5 and the like, the suction portion 28 is formed by connecting a suction pipe seat 28a and a suction pipe 28b with a seal ring 28c interposed therebetween, and the suction pipe seat 28a is between the one side wall. Is inserted into the cylinder body 12 with a seal ring 28d interposed therebetween. The suction pipe 28b is connected to a return pipe (not shown) that forms a flow path for returning the liquid that has passed through the heat radiating unit (not shown) to the suction chamber S.

  The cylinder head 13 is formed by connecting a head main body 20 and a discharge pipe 21 with a seal ring 22 interposed therebetween, and the head main body 20 has a seal ring 23 between the opening end of the cylinder main body 12. The fixed part 14 is shared and connected to the cylinder body 12 by being sandwiched. Connected to the discharge pipe 21 is a supply pipe (not shown) that forms a flow path for guiding the liquid to the heat receiving part (not shown).

  The discharge valve 11a is a check valve that is responsible for communication between a pump chamber, which will be described later, and the outside of the cylinder 11, and for disconnecting the communication. The discharge valve 11a is formed of a valve body, a valve body 25, and a valve body receiver 26. ing. The valve body also serves as the head body 20 and has a valve seat surface 27. The valve body 25 that comes into contact with and separates from the valve seat surface 27 is made of, for example, a ball, and is accommodated in the head body (valve body) 20. The valve body receiver 26 is attached to the head body (valve body) 20 and is formed in a lattice shape or the like so as to allow passage of liquid while preventing the valve body 25 from coming off. In the discharge valve 11 a, a spring may be sandwiched between the valve body 25 and the valve body receiver 26, and the spring may be urged so as to press the valve body 25 against the valve seat surface 27.

  The piston 31 includes a piston head 32 and a piston shaft 33 in which the head 32 is integrally formed at one end. The peripheral surfaces of the piston head 32 and the piston shaft 33 are formed by a polished surface with a predetermined surface accuracy that has been subjected to a polishing process, but it does not prevent the metal plating layer from being deposited on the peripheral surfaces. The piston 31 can be made of a material having the same hardness as that of the cylinder 11, preferably the same kind of metal material. When a metal plating layer is provided, at least the plating layer can be made the same hardness as the cylinder 11.

  The piston head 32 has a circular shape and is accommodated in the head sliding hole 12a. The piston head 32 partitions the head sliding hole 12a into a pump chamber P and a suction chamber S. The pump chamber P is formed between the piston head 32 and the back wall 12 b, and the suction chamber S is formed between the piston head 32 and the cylinder head 13. The diameter of the piston head 32 is slightly smaller than the diameter of the head sliding hole 12a, and a fitting gap G that allows leakage between the pump chamber P and the suction chamber S is provided between them.

  As shown in FIGS. 6 and 7, the piston shaft 33 having a smaller diameter than the piston head 32 has a circular cross section in a direction orthogonal to the axial direction. The piston shaft 33 slidably penetrates the piston through hole 15a and is supported by the through hole 15a.

  The piston 31 is provided with a check valve 34 that is responsible for communication between the pump chamber P and the suction chamber S and for disconnecting the communication. The check valve 34 has a valve seat surface 35a at an intermediate portion, a communication passage 35 provided in the piston 31 over the pump chamber P and the suction chamber S, and a valve body 36 that contacts and separates from the valve seat surface 35a. The valve body receiver 37 is formed. The valve body 36 is made of, for example, a ball and is accommodated in the communication path 35. The valve body receiver 37 is attached to the piston head 32, and is formed in a lattice shape or the like so as to allow passage of liquid while preventing the valve body 36 from coming off. In this check valve 34, a spring may be sandwiched between the valve body 36 and the valve body receiver 37, and the spring 36 may be urged so as to press the valve body 36 against the valve seat surface 37.

  The shaft end portion 33a of the piston shaft 33 protruding to the outside of the cylinder 11 is separate from, for example, a sliding shaft portion penetrating the piston through hole 15a, and is screwed into the sliding shaft portion and integrally connected. Yes. The shaft end portion 33 a has an annular flange pressing portion 38. The flange pressing portion 38 is formed by a flange protruding from the outer periphery of the shaft end portion 33a. In addition, the flange pressing part 38 can also be formed in the level | step difference formed by making the shaft end part 33a of the piston shaft 33 into a small diameter. A second pressing member 39 is fixed to the shaft end portion 33a by a fixing component 40 such as a screw. The second pressing member 39 is made of a disk and has an outer diameter larger than the diameter of the flange pressing portion 38. Thereby, the peripheral part of the 2nd pressing member 39 is used as the protrusion part 39a with respect to the outer periphery of the 2nd flange 43 mentioned later.

  The pumping member 41 is made of a bellows formed of a rubber-like elastic material and has liquid resistance and flexibility. The pumping member 41 has a cylindrical shape with both ends opened, and has a first flange 42 integrally at one end opening edge, and an opening edge at the other end and second flange 43 integrally. Yes. In the present invention, the term “cylindrical shape” refers to a shape in which both ends are opened, and includes an accordion shape as well as a shape in which an intermediate portion swells from both end openings as shown in the figure. .

  Examples of the rubber-like elastic material for forming the pumping member 41 include silicone rubber, EPDM, and fluororesin. When the liquid is a chemical, it is preferable to use a silicone rubber having chemical resistance. In the case where priority is given to the softness of the pumping member 41, it is preferable to use EPDM which is excellent in softness. When the pumping member 41 is made of EPDM, the pumping member 41 is easily deformed flexibly with expansion and contraction, and the expansion and contraction speed is increased, so that the pump performance can be improved and the power consumption of the motor unit 50 is also reduced. Can be reduced.

  As shown in FIG. 8, the first flange 42 projects so as to project outside the pumping member 41, and has an annular convex portion 42 a integrally on its side surface. The first flange 42 is sized to be accommodated in the flange set groove 16, and the thickness A of the first flange 42 from the annular convex portion 42a in the free state to the other side surface of the first flange 42 is: It is slightly thicker than the depth of the flange set groove 16. The second flange 43 protrudes from the inside of the pumping member 41 and has an annular protrusion 43a integrally on its side surface. The thickness B of the second flange 43 from the annular convex portion 43a to the other side surface of the second flange 43 in the free state is slightly larger than the separation distance between the flange pressing portion 38 and the second pressing member 39. By setting the second flange 43 inward, the second flange 43 side of the pumping member 41 is formed to have a smaller diameter than the first flange 42.

  Between the first flange 42 and the second flange 43 of the pumping member 41, a flexible portion is formed, and a central portion 41 a and a connecting portion 41 b between the flexible portion and the first flange 42. The thickness of the connecting portion 41c between the flexible portion and the second flange 43 is the thickness of the portion between the central portion 41a and the connecting portion 41b and the thickness of the portion between the central portion 41a and the connecting portion 41c. Thicker than. In other words, the thickness of the portion where the flexible deformation is large in the flexible portion is made thicker than the thickness of the portion where the flexible deformation is small. Thereby, durability of a site | part with a large flexible deformation can be improved. At the same time, since the portion where the deformation is small is thin, the amount of material used to form the pumping member 41 can be reduced, and the cost of the pumping member 41 can be reduced.

  The pumping member 41 is disposed across the cylinder 11 and the piston 31. That is, the first flange 42 accommodated in the flange set groove 16 penetrates the cylinder 12 with the first presser member 46 having the same outer shape as the cylinder body 12 on the outer surface of the inner wall 12 b of the cylinder 11. The fixed part 14 is shared and connected to be sandwiched between the first pressing member 46 and the inner surface of the flange set groove 16. By this clamping, the first flange 42 is elastically deformed to be brought into close contact with the inner surface of the flange set groove 16 and the first pressing member 46 to exhibit a sealing function, and the liquid tightness from the inside of the pumping member 41 to the outside. Can be secured. In this case, the force for connecting the first pressing member 46 is concentrated on the annular convex portion 42a that hits the inner surface of the flange set groove 16, so that the annular convex portion 42a is crushed and the sealing function is reliably exhibited. Is done. The first pressing member 46 has a conical relief for allowing the pumping member 41 to be flexibly deformed.

  The second flange 43 is connected to the piston shaft 33 by a fixing part 40 in a state where the second flange 43 is put on the flange pressing portion 38 of the piston shaft 33, thereby connecting the second pressing member 39 and the flange. It is sandwiched between the presser part 38. By this clamping, the second flange 43 is elastically deformed to be brought into close contact with the flange pressing portion 38 and the second pressing member 39 to exhibit a sealing function, thereby ensuring liquid tightness from the inside of the pumping member 41 to the outside. . In this case, the force for connecting the second presser member 39 is concentrated on the annular convex portion 43a hitting the second presser member 39, so that the annular convex portion 43a is crushed and the sealing function is reliably exhibited. Is done.

  A tank chamber 47 is formed between the inner surface of the pumping member 41 attached in this way and the piston shaft 33 disposed at the center thereof. The tank chamber 47 communicates with the suction chamber S through the liquid passage hole 15b. Since a part of the liquid in the pump chamber P leaks through the fitting gap G when the pressure in the pump chamber P is increased in the suction chamber S, the leaked liquid is received from the suction chamber S into the tank chamber 47 through the liquid passage hole 15b. be able to. The circulated liquid is filled in advance in the pump chamber P, the suction chamber S, the tank chamber 47, and all the flow paths (not shown).

  As shown in FIGS. 4 to 6, the motor unit 50 includes a motor base 51, an electric motor 52, and an output gear 53.

  The motor base 51 is fixed to the other side wall of the cylinder body 12. This fixing is performed by inserting the positioning pins 54 and 55 of the motor base 51 into the positioning holes 17 and 18 and positioning the fixing pins 56 shown in FIG. 12 by screwing in.

  A stepping motor is used as the electric motor 52. The electric motor 52 is driven for an appropriate time by a motor driver (not shown). The electric motor 52 is screwed to the motor base 51. An output gear 53 is fixed to the output shaft 52 a of the electric motor 52. It is also possible to make the output gear 53 integrally with the output shaft 52a by cutting teeth on the output shaft 52a. In the motor unit 50, the output shaft 52a and the output gear 53 are arranged in the direction in which the pumping member 41 extends (upward in FIGS. 4 to 6), and the motor base 51 is fixed to the cylinder body 12 as described above. By the side of the pump 10.

  As shown in FIGS. 4 to 6, the transmission unit 60 is disposed across the pump 10 and the motor unit 50. The arrangement of the transmission unit 60, the pump 10, and the motor unit 50 prevents the motor unit 50 from being continuously arranged in the axial direction with respect to the pump 10. This device 1 can be made compact.

  The transmission unit 60 includes a transmission unit base 61, a cover 62, a transmission element 63, a motion conversion unit 64, and a drive member 65.

  The transmission portion base 61 having a rectangular shape in plan view is positioned by fitting the concave and convex portions on the end surface of the motor base 51 on the output shaft 52a side so as to cover the second pressing member 39. The cover 62 having a rectangular shape in plan view is placed on the transmission base 61 from the side opposite to the motor base 51 and is positioned on the base 61 by concave and convex fitting. The superimposed transmission base 61 and cover 62 are inserted through the fixing screw 66 (see FIGS. 3 and 5) inserted into the motor base 51, and the transmission base 61 and cover 62 are inserted. The motor unit 50 and the pump 10 are connected to each other by a fixing screw 67 (see FIGS. 3 and 5) screwed into one pressing member 46. An output gear 53 is inserted into a through hole 60 a formed continuously in the transmission portion base 61 and the cover 62.

  The transmission element 63 and the motion conversion unit 64 are disposed between the transmission unit base 61 and the cover 62, respectively. The transmission element 63 is rotatably supported by a pair of bearings 67 provided corresponding to the transmission part base 61 and the cover 62, and similarly, the motion conversion part 64 is provided on each of the transmission part base 61 and the cover 62. A pair of bearings 68 provided correspondingly are rotatably supported.

  The transmission element 63 has a large gear 63a and a small gear 63b. The large gear 63 a is meshed with the output gear 53. The motion converter 64 is a cam body with a gear 64a, and the gear 64a is meshed with the small gear 63b. The motion converting portion 64 has a cam groove 64b that is inclined with respect to the axis and continues in a ring shape.

  The drive member 65 is slidably supported on the guide shaft 69 along the axial direction. As shown in FIGS. 3 to 5, the guide shaft 69 has one end connected to one corner of the cover 62 and the other end connected to one corner of the first pressing member 46. They are arranged in parallel. As a result, the guide shaft 69 is disposed obliquely with respect to the direction in which the pump 10 and the motor unit 50 are arranged, so that the guide shaft 69 and the guide shaft 69 are arranged in the projection region without increasing the size of the transmission unit 60. The supported drive member 65 can be accommodated.

  The drive member 65 has, for example, a roller 65d as a cam follower protruding laterally at one end thereof. The roller 65d is inserted so as to make rolling contact with the cam groove 64b. Since the rotational motion of the motion converting portion 64 is converted into the reciprocating motion of the drive member 65 through the engagement of the cam groove 64b and the roller 65d, the drive member 65 follows the guide shaft 69 along the axial direction of the piston 31. It is provided so that it can reciprocate. Therefore, the electric motor 52 that rotates in one direction can be used to reciprocate the piston 31 in the axial direction as will be described later.

  The driving member 65 has a first locking portion 65a and a second locking portion 65b on the other end side, and has a fitting groove 65c formed therebetween. The fitting groove 65 c is fitted to a peripheral portion of the second pressing member 39, that is, a part of the protruding portion 39 a that protrudes outward with respect to the outer periphery of the second flange 43.

  The coolant discharge apparatus 1 having the above-described configuration is used as follows while maintaining the state in which the tank chamber 47 and the portion through which the liquid passes are filled as described above.

  The state of FIG. 6 shows the pump suction process in the non-operating state and the operating state of the liquid discharging apparatus 1, and the state of FIG. 7 shows the pump discharging process in the operating state of the coolant discharging apparatus 1. In the non-operating state and the pump suction process, since the motor unit 50 is in a standby state, the pumping member 41 is held in an extended state.

  When the electric motor 52 of the motor unit 50 is operated, the rotation of the output gear 53 is decelerated and transmitted to the motion conversion unit 64 via the transmission element 63, so that the motion conversion unit 64 is rotated at a predetermined speed. Each time the motion converting portion 64 rotates 180 degrees, the drive member 65 reciprocates while reversing the sliding direction along the guide shaft 69 via the roller 65d engaged with the cam groove 64b. When the reciprocating drive member 65 moves forward toward the cylinder body 12, the first holding portion 65 a presses the second pressing member 39 close to the cylinder body 12 and moves away from the cylinder body 12. During the movement, the second pressing member 39 is pulled away from the cylinder body 12 by the second locking portion 65b.

  Since the piston 31 is pushed at the same time as the second pressing member 39 is pushed to the cylinder body 12 side by the driving member 65, the pumping member 41 can be swelled outward as shown in FIG. Deformed. As a result, the internal pressure of the tank chamber 47 is increased, and at the same time, the piston head 32 is discharged and brought closer to the valve 11a, and the pump chamber P is contracted to increase its internal pressure, while the volume of the suction chamber S is increased. The internal pressure decreases.

  As the push-in of the piston 31 proceeds, the check valve 34 of the piston 31 is closed and the internal pressure of the pump chamber P is further increased, so that the liquid filled in the pump chamber P is discharged from the valve 11a. It pushes open and is discharged outside from this valve 11a. On the other hand, a part of the liquid in the pump chamber P having a high pressure flows into the suction chamber S in which the pressure decreases through the fitting gap G between the cylinder 11 and the piston 31. At the same time, the liquid recirculated to the suction portion 28 is sucked into the suction chamber S through the suction portion 28 and a part of the liquid in the tank chamber 47 pressurized by the pumping member 41 is passed through the liquid passage hole. Inhaled through 15b. The amount of liquid leaking into the suction chamber S through the fitting gap G and the amount of liquid returned from the tank chamber 47 to the suction chamber S are compared with the amount of liquid sucked into the suction chamber S from the suction portion 28. There are few. When the amount of leakage through the fitting gap G is small, a sufficient fluid pressure for pushing and opening the discharge valve 11a can be obtained in the pump chamber P. The above-described liquid discharge ends when the piston 31 is pushed in a predetermined stroke by the cam groove 64b. Note that the leakage due to the pumping operation is not limited to the fitting gap G, and other leakage means can be employed depending on the application.

  Thereafter, since the driving member 65 is double-acted, the piston 31 is pulled back from the pushing position shown in FIG. 7 to the drawing position shown in FIG. As the piston 31 is pulled back, the piston head 32 is moved away from the cylinder head 13 and the volume of the pump chamber P is expanded and the internal pressure is decreased. On the other hand, the volume of the suction chamber S is decreased and the internal pressure is increased. The check valve 34 is opened, and the pump chamber P and the suction chamber S communicate with each other. For this reason, the liquid in the suction chamber S is supplied to the pump chamber P through the communication path 35.

  At the same time, as the piston 31 is pulled back, the pumping member 41 is flexibly deformed to be stretched, so that the internal pressure of the tank chamber 47 is lowered. Therefore, a part of the liquid in the suction chamber S having a high pressure flows into the tank chamber 47 through the liquid passage hole 15 b and is stored in the tank chamber 47.

  As described above, the coolant discharge device 1 can circulate the amount of liquid corresponding to the number of repetitions by the pump 10 as the piston 31 reciprocates with respect to the cylinder 11. In this case, the cooling liquid discharging apparatus 1 performs a liquid discharging operation in consideration of liquid leakage between the head sliding hole 12 a of the cylinder 11 and the piston head 32 of the piston 31. In other words, a small amount of liquid controlled to be a predetermined amount is discharged from the pump chamber P and discharged through the valve 11a without using a seal ring that is elastically strongly in close contact with the inner surface of the head sliding hole 12a. Yes.

  Thus, unlike the configuration using a seal ring that is elastically strongly in close contact with the inner surface of the cylinder 11, 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 31 with respect to the inner surface of the cylinder 11 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 cylinder 11 and the piston 31 as compared with a configuration using a seal ring that is elastically strongly and rubbed against the inner surface of the cylinder 11. For this reason, the driving force of the piston 31 can be small, and the electric motor 52 of the motor unit 50 can be used with a smaller electric torque and hence a small electric motor.

  In the above-described operation, the piston 31 has one axial end portion supported by the head sliding hole 12a and the axial intermediate portion supported by the piston through hole 15a. Thereby, the wobbling of the piston 31 is effectively suppressed, and the piston 31 can be stably reciprocated along the axial direction thereof, so that the quantitative discharge operation is smooth.

  Further, in the cooling liquid discharge device 1 having the above-described configuration, the liquid stored in the tank chamber 47 formed inside the cylindrical pumping member 41 is pushed by the pumping member 41 to increase the pressure in the tank chamber 47. Leakage to the outside other than the suction chamber S is prevented by the pumping member 41.

  That is, the first flange 42 of the pumping member 41 made of a rubber-like elastic material is sandwiched between the back wall 12b of the cylinder body 12 and the first pressing member 46, and the second flange 43 of the pumping member 41 is inserted. Is sandwiched between the flange pressing portion 38 of the piston 31 and the second pressing member 39, and both ends of the pumping member 41 are connected to the cylinder 11 and the piston 31, whereby the flanges 42 and 43 themselves are sealed. Can function as. For this reason, prevention of liquid leakage from the tank chamber 47 to the outside can be realized with a simple configuration without requiring a special sealing member.

  In the cooling liquid discharge device 1 having the above-described configuration, the second flange 43 has a smaller diameter than the first flange 42 of the pumping member 41 as described above, and has protruded from the outer periphery thereof. The fitting groove 65c of the drive member 65 is fitted into the protruding portion 39a of the second pressing member 39, and the pump 10 and the transmission portion 60 are connected. With this configuration, the distance between the drive member 65 and the piston shaft 33 in the radial direction of the piston 31 is shortened. For this reason, it is suppressed that the length of the transmission part 60 along the direction where the pump 10 and the motor part 50 are located in a line is suppressed, and it can contribute to size reduction of the cooling fluid discharge apparatus 1. FIG.

  In addition, since the pumping member 41 is forcibly expanded and contracted by fitting the driving member 65 to the second pressing member 39 and reciprocating the piston 31, the speed required for expansion and contraction of the pumping member 41 depends on the driving mechanism. Let me speed up. In addition, in order to extend the pumping member 41 that has been compressed, it is also possible to naturally extend by the restoring action due to the elasticity of the pumping member 41. However, in this case, since it takes a long time to restore, the number of pumping times per unit time decreases, but such a problem is not the above-described configuration. Further, in order to increase the speed of extending the compressed pumping member 41, it is conceivable to bias the pumping member 41 in the extending direction with a coil spring. However, in this case, the number of parts increases, which is not preferable, and the resistance of the coil spring is added to compress the pumping member 41, so that an electric motor having a large torque is required or pumping is required when such a motor is not used. Although the member 41 is pushed and contracted for a long time, the number of pumping times per unit time is reduced, but such a problem is not the above configuration.

  In the coolant discharge apparatus 1 having the above-described configuration, each of the pump 10, the motor unit 50, and the transmission unit 60 is a unit. Therefore, each of the pump 10, the motor unit 50, and the transmission unit 60 is a unit in advance. Since the entire coolant discharge device 1 can be assembled in this state, the assembly workability can be improved. In addition, since the second flange 43 has a smaller diameter than the first flange 42 of the pumping member 41, the first flange 42 to the cylinder 11 using the first pressing member 46 is assembled in the assembly of the pump 10. And the attachment of the second flange 43 to the piston 31 using the second pressing member 39 can be performed from the same direction toward the cylinder 11 side. In this respect, the workability of mounting the pumping member 41 in the assembly of the pump 10 is good.

  The liquid discharge apparatus of the present invention can be used for applications other than the above-described cooling liquid circulation, for example, for injecting a small amount of chemical liquid, and also for other applications.

1 is a front view showing a liquid ejection device according to an embodiment of the present invention. The bottom view which shows the liquid discharge apparatus of FIG. The perspective view which shows the liquid discharge apparatus of FIG. The perspective view which expands and shows the liquid discharge apparatus of FIG. The perspective view which decomposes | disassembles and shows the liquid discharge apparatus of FIG. Sectional drawing which shows the liquid discharge apparatus of FIG. Sectional drawing which expands and shows the pump of the liquid discharge apparatus of FIG. Sectional drawing which shows the pumping member with which the pump of FIG. 7 is provided.

Explanation of symbols

1 ... Cooling liquid discharge device (liquid discharge device)
DESCRIPTION OF SYMBOLS 10 ... Pump 11 ... Cylinder 11a ... Discharge valve 12 ... Cylinder main body 12a ... Head sliding hole 13 ... Cylinder head 15a ... Piston through-hole 15b ... Liquid through-hole 16 ... Flange set groove 20 ... Head main body 28 ... Inhalation part 31 ... Piston 32 ... Piston head 33 ... Piston shaft P ... Pump chamber S ... Suction chamber G ... Fitting gap 34 ... Check valve 35 ... Communication passage 38 ... Flange presser 39 ... Second presser member 39a ... Projection part 41 ... Pumping member 42 ... first flange 43 ... second flange 42a, 43a ... annular convex part 46 ... first pressing member 47 ... tank chamber 50 ... motor part (drive mechanism)
52 ... Electric motor 52a ... Output shaft 53 ... Output gear 60 ... Transmission section (drive mechanism)
64 ... motion conversion part 64b ... cam groove 65 ... drive member 65a ... first locking part 65b ... second locking part 65c ... fitting groove 65d ... roller 69 ... guide shaft

Claims (7)

A liquid discharge device comprising a pump and a drive mechanism for operating the pump, wherein the piston is pushed into the cylinder of the pump to discharge the liquid sucked through the suction portion and filling the pump chamber;
The pump
The cylinder;
The piston fitted to the cylinder and provided to leak from a gap between the cylinder and the cylinder;
A first flange and a second flange are individually formed at both ends and formed of an elastic material. The first presser member connected to the cylinder and the cylinder make the first flange liquid-tight. A tank chamber in which the second flange is tightly liquid-tightly provided by the piston and the second presser member connected to the piston, and the liquid leaking from the gap is accommodated inside. And a cylindrical pumping member that expands and contracts following the reciprocating movement of the piston.   The first flange protrudes outside the pumping member, the second flange protrudes inside the pumping member, and the second flange is held by an annular flange presser provided on the piston. The liquid discharging apparatus according to claim 1, wherein the liquid pressing device is closely attached by a portion and the second pressing member connected to the piston.   The annular convex part closely contacting with the cylinder is provided integrally with the first flange, and the annular convex part closely contacting with the second pressing member is provided integrally with the second flange. Liquid discharge device. The drive mechanism is
An output gear and an electric motor for rotating the gear; and a motor unit arranged on the side of the pump by arranging the output gear in a direction in which the pumping member extends,
A driving member connected to the second pressing member and reciprocatingly moved in the axial direction of the piston; and a motion converting unit for converting rotation of the output gear into reciprocating movement of the driving member; The liquid discharging apparatus according to claim 2, further comprising: a transmission unit disposed across the pump.   The second pressing member has a protruding portion that protrudes outward with respect to the outer periphery of the second flange, and the pump and the transmission portion are connected by fitting the driving member into the protruding portion. The liquid discharging apparatus according to claim 4.   The liquid discharging apparatus according to claim 4 or 5, wherein each of the pump, the motor unit, and the transmission unit is a unit.   An electronic apparatus in which the liquid ejection device according to claim 6 is incorporated.

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