JP2009154073A - Fluid discharger and fluid supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid discharger, which prevents dripping from a discharging part. <P>SOLUTION: The fluid discharger 1 comprises a pump 2 having the discharging part 6 of a fluid, and an openable and closable closing device 11 attached to the discharging part 6. The closing device 11 has a valve seat ring 16 provided around a discharge opening 6a in the discharging part 6, a valve body 17 closing the discharge opening 6a by the seating from the outward of the discharge opening 6a to the valve seat ring 16, and a coil spring 19 biasing so as to press the valve body 17 to the valve seat ring 16. When the pressure of the fluid in the discharging part 6 reaches a predetermined pressure, the valve body 17 opens the discharge opening 6a to constitute a first channel 28 through which the discharge fluid passes, and the valve body 17 is constituted to close the first channel 28 when the pressure turns to the predetermined pressure or less. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fluid discharge device that discharges a fluid such as a sealant, grease, and adhesive, for example, and a fluid supply system including the fluid discharge device.

  FIG. 5 shows an example of a fluid supply system. In this system, for example, in an automobile assembly factory or the like, a fluid discharge device (incorporated with a low-pressure pump) for supplying a high-viscosity fluid such as a sealant, grease, or adhesive to a work (not shown) such as a vehicle body (Hereinafter also referred to as a dispenser) 63 is used. In the fluid supply system including the dispenser 63, the fluid is supplied from the storage tank 61 to the dispenser 63 through the supply line 64 by the high-pressure pump 62 (see, for example, Patent Documents 1 and 2). The supply line 64 is provided with a pressure reducing valve 65 and an accumulator 66. The pressure reducing valve 65 adjusts the fluid pressurized by the high pressure pump 62 to an appropriate pressure. The accumulator 66 is for maintaining the proper pressure of the fluid supplied to the dispenser 63. The dispenser 63 pressurizes the fluid supplied at a predetermined pressure and discharges and supplies it to a predetermined part of the workpiece.

  A known uniaxial eccentric screw pump 67 as shown in FIG. 6 is generally used as the dispenser 63. 6 (a) is a partial longitudinal sectional view of the uniaxial eccentric screw pump 67, FIG. 6 (b) is a sectional view taken along the line VIB-VIB, and FIG. 6 (c) is a sectional view taken along the line VIC-VIC. is there. This uniaxial eccentric screw pump 67 is a rotary positive displacement pump, and includes a rotor 68 and a stator 69. The rotor 68 is a member having a perfect circular cross section that is spirally twisted into a male screw shape. The stator 69 is a member having an inner hole 70 having an oval cross section, which has a shape of two female threads over the entire length. The rotor 68 is inserted into the inner hole 70. The inside of the inner hole 70 is divided into a plurality of fixed volume portions 70 a along the longitudinal direction by a contact portion between the rotor 68 and the inner peripheral surface of the inner hole 70. The rotor 68 is rotationally driven by a motor 72 via, for example, a universal type eccentric joint 71. As the rotor 68 rotates, the respective volume portions 70a are moved from the fluid supply portion 73 toward the discharge portion 74, and the fluid therein is discharged.

Generally, in a low-pressure single-shaft eccentric screw pump, in order to prevent pressure loss and a decrease in discharge efficiency, the stator is often formed of rubber so that the rotor is in close contact with the inner hole of the stator without a gap. However, when a flexible material is used for the stator of a high-pressure single-shaft eccentric screw pump that discharges a high-viscosity fluid such as the sealant, there is a risk of causing wear, deformation, breakage, and the like. Therefore, hard resin, ceramic, metal or the like is selected as the material for the stator of the high-pressure pump. In that case, in order to ensure smooth rotation of the rotor 68, a slight gap is provided at the contact portion between the rotor 68 and the stator 69. On the other hand, regardless of whether the dispenser 63 is operated or stopped, the internal fluid from the accumulator 66 to the dispenser 63 through the supply line 64 is constantly pressurized to a predetermined pressure, as described above. As a result, even if the operation of the dispenser 63 is stopped, a small amount of fluid may leak to the discharge side (so-called “liquid dripping” from the discharge portion) through the gap between the rotor 68 and the inner hole 70 of the stator 69. .
JP 2004-249243 A JP 2004-298862 A

  The present invention has been made to solve the above-described problems. In the fluid supply system, even when pressurized fluid is constantly supplied from the upstream side to the fluid discharge device, Providing a fluid ejection device that can prevent fluid leakage from the ejection port by stopping the operation of the fluid ejection device and smoothly eject the fluid when reactivated, and the fluid ejection device It aims at providing the fluid supply system provided with.

The fluid ejection device of the present invention is
A pump having a fluid discharge part;
An opening and closing device attached to the discharge part of the pump,
The closing device constitutes a first flow path that opens when the pressure of the internal fluid in the discharge section reaches a predetermined pressure, and through which the discharge fluid passes, and when the pressure drops below the predetermined pressure, It is configured to close.

  According to such a configuration, by setting the set pressure of the closing device to, for example, about the set discharge pressure of the pump, when the pressure of the fluid in the discharge portion reaches the discharge pressure by the operation of the pump, the closing device opens and the fluid Can be discharged. In addition, when the pump operation is stopped and the pressure of the fluid in the discharge section drops below the discharge pressure, the closing device closes, so even if there is an internal pressure below the set discharge pressure inside the pump, the fluid from the discharge section Leakage (dripping) is prevented.

  Further, in addition to the above configuration, the closing device includes a state in which the internal pressure of the pump becomes lower than the external pressure in the discharge unit by a predetermined differential pressure when the first flow path is closed. A structure may be provided in which a second flow path is formed through which fluid to be opened and sucked passes, and the second flow path is closed when the pressure difference becomes smaller than the differential pressure. When configured in this manner, the fluid remaining outside the discharge section can be sucked into the pump again in a state where the fluid discharge device stops discharging the fluid. That is, when the pump discharge portion is set to a negative pressure by rotating the pump in the reverse direction, the fluid remaining outside and near the discharge portion can be sucked without dropping. In this case, since the discharge unit has a negative pressure, the closing device maintains the first flow path for discharge closed, and thus does not affect the suction operation.

  During the suction operation, the pressure for opening the second flow path of the closing device is set to be lower than a predetermined suction pressure (differential pressure from the external pressure, which is generally atmospheric pressure). When the fluid pressure reaches the suction pressure (negative pressure), the closing device is opened, and the fluid can be sucked. Further, when the operation of the pump is stopped and the pressure of the fluid in the discharge part becomes higher than the suction pressure (negative pressure), the second flow path is closed. Therefore, even if a negative pressure is present inside the pump, leakage of internal fluid from the discharge part serving as a suction port is prevented. Moreover, even if the fluid ejection device resumes the ejection operation, there is no adverse effect because the second flow path is closed.

  The closing device includes a first valve seat provided as a component around the discharge port in the discharge unit, and the discharge port is closed by seating on the first valve seat from the outside of the discharge port. And a first elastic member that urges the first valve body to press the first valve body against the first valve seat. In addition to this configuration, the second flow path for communicating the inside and the outside of the pump is formed in the first valve body, and a second valve seat is formed in the second flow path. A second valve body for closing the second flow path by being seated from the inside of the second flow path with respect to the valve seat is incorporated, and the second valve body is urged to be pressed against the second valve seat. A second elastic member can be further incorporated. Then, after the first flow path for discharge is closed by the first valve body, when the discharged fluid remains outside the discharge port, it can be sucked through the second flow path. it can. Further, the second flow path can be closed by the second valve body after the suction.

  In order to stabilize the closing function of the closing device, the first valve body or the second valve body may be formed from a sphere.

  In order to further improve the closing function of the closing device, the first valve seat or the second valve seat is formed with a partial conical valve seat surface that contacts the first valve body or the second valve body and seals the fluid. May be.

  The closing device includes a housing having the first valve seat, the first valve body, and the first elastic member and having a fluid outlet. The housing is detachably attached to the discharge portion of the pump. It is also possible to configure the elastic member to be exchangeable with an elastic member having different characteristics as required. Similarly, the second valve body and the second elastic member are detachably installed in the second flow path of the first valve body, and the second elastic member is configured to be exchangeable with an elastic member having different characteristics. Is also possible. Here, the characteristics of the elastic member include a spring constant, total deflection, free length, and the like. Therefore, even when the discharge pressure or the suction pressure is changed, it can be easily handled.

  A uniaxial eccentric screw pump can be used as the pump. This pump includes a stator having an inner hole with an oval cross section having two female screw shapes, and a rotor with a perfect circular section that is spirally twisted into a male screw shape, and the rotor is an inner hole of the stator. Is rotatably inserted in the.

The fluid supply system of the present invention includes:
Any one of the fluid ejection devices described above;
A fluid supply line for supplying fluid to the fluid ejection device;
A fluid pressurizing device provided in the fluid supply line for pumping fluid toward the fluid discharge device.

  According to the present invention, in the fluid supply system or the like, when the fluid discharge operation of the fluid discharge device at the tip of the fluid supply system is stopped, the discharge portion is closed, and unnecessary fluid leakage from the discharge portion is prevented. Therefore, contamination of the workpiece to be processed, the fluid supply system, etc., waste of the supply fluid, and the like are avoided.

  Hereinafter, embodiments of a fluid discharge device and a fluid supply system according to the present invention will be described with reference to the accompanying drawings. FIG. 1A is a longitudinal sectional view showing a distal end portion of a fluid ejection device (hereinafter referred to as a dispenser) 1 according to the embodiment, that is, a closing device 2. FIG.1 (b) is the II sectional view taken on the line of Fig.1 (a). FIG. 2 is a perspective view before assembly showing interior parts of the closing device 2 of FIG.

  The uniaxial eccentric screw pump 2 described above is used as the discharge driving unit of the dispenser 1 shown in the figure. Therefore, description of the configuration and function of the pump 2 is omitted. FIG. 1 shows only the stator 3 of the pump 2, the rotor 4, and the inner hole 5 of the stator 3. The inner hole 5 is partitioned into a plurality of volume portions 5 a by the rotor 4.

  A closing device 11 is detachably attached to the discharge portion 6 of the pump 2. The closing device 11 opens when the pressure of the internal fluid in the discharge unit 6 reaches a predetermined pressure set in the closing device 11, and enables the pump 2 to discharge the fluid. And it closes when the pressure of the internal fluid in the discharge part 6 becomes below the said predetermined pressure, and prevents that an internal fluid leaks from the discharge part 6 to the exterior. In order to realize this function, the closing device 11 has the following configuration.

  The closing device 11 includes a housing 12. The base end portion 12a of the housing 12 is detachably screwed to the outer peripheral side of the discharge portion 6 of the pump 2 via an O-ring 7 for sealing with the outside. A discharge nozzle 15 is detachably attached to the discharge hole 13 at the tip of the housing 12 by a union nut 14. The inner diameter of the discharge hole 13 is much smaller than the inner diameter of the housing 12. Inside the housing 12, a mechanism for elastically closing the discharge port 6a of the pump 2 is provided. This mechanism includes a valve seat ring 16, a spherical valve body 17 that is seated on the valve seat ring 16 and seals the fluid, a general spring seat member 18, a coil spring 19 as an elastic member, and a spring receiving spacer. 20. These members are arranged coaxially along the central axis CL of the housing 12 in the order described above from the pump 2 side (see also FIG. 2). The coil spring 19 is incorporated with an initial deflection, and urges the valve body 17 to press against the valve seat ring 16.

  FIG. 3 is a partially cutaway perspective view showing the inside of the housing 12. As is apparent from FIGS. 1B and 3, four ridges 21 parallel to the axis CL direction are formed on the inner peripheral surface of the housing 12 every 90 ° in the circumferential direction. The protrusion 21 is for guiding the movement of the valve element 17 in the direction of the axis CL. Of course, the protrusion 21 is not limited to four, and may be three or five or more. Even if there are two, if the width of the ridge is widened, the valve element 17 can be guided. Moreover, the concave part 22 of the partial cylindrical surface formed between the protrusions 21 is for ensuring the flow path of the fluid discharged when the closing device 11 opens. In FIG. 1A, the recess 22 is shown in the upper half of the center axis CL, and the protrusion 21 is shown in the lower half of the center axis CL. Of the inner peripheral surface of the housing 12, the protrusion 21 and the recess 22 are not formed for the spacer holding portion 23 into which the spacer 20 is inserted and the valve seat holding portion 27 into which the valve seat ring 16 is inserted. The inner circumferential surface of the protrusion 21 is formed as an inner circumferential surface having the same radius. This is because the spacer 20 and the valve seat ring 16 are fitted without play.

  As shown in FIG. 2, the spacer 20 has a central portion 20 a opened to secure a flow path for the fluid to be discharged. Furthermore, four arc-shaped notches 24 are formed on the outer peripheral surface of the spacer 20 at intervals in the circumferential direction in order to secure a flow path for the fluid to be discharged. Therefore, even if the coil spring 19 is compressed and the strands are brought into close contact with each other, a fluid flow path is secured. The notch 24, the recess 22, between the strands of the coil spring 19, and the central opening 20 a of the spacer 20 constitute a first fluid flow path 28. Further, a leg portion 25 is formed between the cutout portions 24. In FIG. 1A, the arc-shaped cutout portion 24 of the spacer 20 is shown in the upper half of the central axis CL, and the leg portion 25 is shown in the lower half of the central axis CL. The spacer 20 is positioned and held when the outer periphery of the leg portion 25 is in contact with the spacer holding portion 23 and one end portion of the leg portion 25 is in contact with the stepped portion 26 on the front end side inside the housing 12. Further, one end portion of the coil spring 19 is fitted inside the four leg portions 25 in the radial direction. The illustrated coil spring 19 employs a plate-like element wire, but is not limited to such a configuration. A strand having a circular cross section may be used. This also applies to the second coil spring 39 (FIG. 4) described later.

  The central opening of the valve seat ring 16 is a flow path through which fluid flows, and this central opening communicates with the inner hole 5 of the stator 3 of the pump 2. The valve seat ring 16 has an outer peripheral surface supported by the valve seat holding portion 27 in the housing 12, and a rear end surface supported by the end surface 3 a of the stator 3 of the pump 2. The rear end face is supported by the side end face 21a. Therefore, the valve seat ring 16 is positioned in the housing 12 while being held between the housing 12 and the stator 3 and is firmly held. The valve seat ring 16 is formed with a valve seat surface (also referred to as a seat surface) 16a for sealing a fluid when the valve body 17 is seated. The valve seat surface 16a is a partial conical surface. If the valve body 17 is seated on the valve seat surface 16a, the discharge port 6a is closed, so that the internal fluid does not flow out from the pump 2.

  As described above, the valve body 17 is elastically seated on the valve seat surface 16 a by the coil spring 19. The spring force due to the initial deflection of the coil spring 19 is smaller than the force applied to the valve body 17 by the set discharge pressure of the pump 2 and is applied to the valve body 17 by the internal pressure of the pump 2 when the pump 2 is stopped. The value is determined to be greater than the force. Therefore, when the pressure of the internal fluid of the pump 2 reaches the set discharge pressure, the force by this pressure overcomes the spring force of the coil spring 19, so that the valve body 17 is pushed and the discharge port 6a is opened to discharge the fluid. The Further, when the pump 2 is stopped and the internal pressure of the pump 2 is reduced, and the force due to this internal pressure is less than the spring force of the coil spring 19, the valve body 17 closes the discharge port 6a, preventing leakage of internal fluid. The

  Although the valve body 17 is not limited to a spherical shape, the spherical shape is particularly effective even if the valve body moves due to the influence of the fluid flow or the like, and always exhibits centripetality with respect to the valve seat ring 16. This is because stable seating on the valve seat surface 16a is possible. This also applies to the second valve element 37 (FIG. 4) described later.

  The spring seat member 18 is formed with a cylindrical convex portion 18 a that is fitted on the inner diameter side of the coil spring 19 and holds the coil spring 19 at the center of one end surface thereof. In the center of the other end surface of the spring seat member 18, a shallow concave portion 18b having a partially spherical shape for seating the valve body 17 is formed. The radius of the partial spherical surface of the recess 18b is substantially the same as or slightly larger than the radius of the valve body. Of course, the recess 18b may be formed in a partial conical shape instead of a partial spherical surface.

  As described above, the housing 12 is detachably screwed to the discharge portion 6 of the pump 2. The valve seat ring 16 is held by the housing 12 and the end surface 3 a of the stator 3. Therefore, if the housing 12 is removed from the pump 2, all the built-in components (the valve seat ring 16, the valve body 17, the spring seat member 18, the coil spring 19 and the spacer 20) can be easily taken out. That is, these parts can be replaced as necessary. For example, when changing the setting of the discharge pressure of the pump 2, the opening / closing pressure of the closing device 11 can be easily changed by changing to a coil spring having different characteristics. For example, a coil spring having a different spring constant may be changed, and its initial deflection may be changed. In that case, the spring seat member 18 and the spacer 20 are also replaced with ones having different sizes and shapes in accordance with changes in the inner diameter and initial deflection of the coil spring.

  FIG. 4 shows another dispenser 31. The dispenser 31 also includes a uniaxial eccentric screw pump 2 and a closing device 32 attached to the discharge unit 6 of the pump 2. FIG. 4A is a longitudinal sectional view showing the distal end portion of the dispenser 31, that is, the closing device 32. FIG. 4B is a cross-sectional view taken along the line IVA-IVA of FIG. The pump 2 has the same configuration as the pump 2 of the dispenser 1 of FIG. This closing device 32 is also opened when the pressure of the internal fluid in the discharge part 6 of the pump 2 reaches a predetermined pressure, and enables the pump 2 to discharge the fluid, and when the pressure of the internal fluid becomes equal to or lower than the predetermined pressure. And a function of preventing leakage of fluid from the discharge part 6. This is the same as the closing device 11. This function is achieved by a valve seat ring 16, a valve body (first valve body) 33, a coil spring 19 and a spacer 20 which will be described later.

  However, this closing device 32 has a further function not found in the closing device 11 of the dispenser 1 of FIG. 1 and a different configuration for it. The further function that the closing device 32 can exhibit is a function that allows the external fluid to be sucked through the discharge portion 6 by rotating the pump 2 backward after the dispenser 31 stops discharging the fluid. This is a function that can close the flow path for the suction.

  After the dispenser 31 stops the discharge operation, the discharge passage (first passage) is closed by the valve body 33, and the fluid in the pump 2 does not leak. However, fluid may adhere and remain outside the discharge unit 6 and in the vicinity of the discharge unit. In such a case, the closing device 32 having a suction function (suck back function) can suck the residual fluid outside the discharge unit 6 back into the pump 2 and prevent it from dripping. Moreover, as will be described later, when the suction operation is stopped, the suction flow path is closed. In this way, a further improved dripping prevention effect can be obtained. Next, the configuration of the closing device 32 will be described.

  The closing device 32 includes a housing 12. The base end portion of the housing 12 is detachably screwed to the outer peripheral side of the discharge portion 6 of the pump 2 via an O-ring 7 for sealing with the outside. Since the structure of the housing 12 is basically the same as that of the housing 12 of the closing device 11 described with reference to FIGS. 1 and 3, the same reference numerals are given and the description thereof is omitted. Further, the valve seat ring 16 accommodated in the housing 12, the coil spring 19 and the spacer 20, and the discharge nozzle 15 connected to the discharge hole 13 at the front end of the housing 12 are also shown in FIG. Since the basic configuration is the same as that of the closing device 11, the same reference numerals are given and the description thereof is omitted.

  As shown in FIG. 4, the first valve body 33 is largely different from the closing device 11 of FIG. The overall structure of the first valve body 33 is generally composed of a substantially spherical tip portion (located on the pump 2 side) 33a and a substantially cylindrical base portion 33b. The partial spherical portion of the distal end portion 33 a contacts the valve seat surface 16 a of the valve seat ring 16 and seals the fluid. A cylindrical spring receiving projection 34 to be inserted into the inner diameter side of the coil spring 19 protrudes from the base end surface of the base 33b coaxially with the base. That is, the first valve body 33 also has a function as the above-described spring seat member 18 (FIG. 1). Further, the outermost peripheral portion of the distal end portion 33 a is guided by the protrusion 21 in the housing 12. Accordingly, the movement of the valve element 33 is restricted by the coil spring 19 and the protrusion 21 and can rotate around the central axis CL (which is also the central axis of the housing), but the valve element 33 is in a plane including the central axis CL. Can not rotate greatly, and can be seated stably on the valve seat ring 16.

  A fluid passage 35 penetrating back and forth along the central axis CL is formed inside the first valve body 33. This passage 35 is a so-called second flow path for the fluid to be sucked. Inside the passage 35, a mechanism for elastically closing the passage 35 is provided. This mechanism includes a valve seat (second valve seat) 36 formed as a step on the inner periphery of the passage 35, and a spherical valve body (second valve body) that is seated on the valve seat 36 and seals fluid. 37, a general spring seat member 38, a coil spring (second coil spring) 39 as a second elastic member, a spring receiving member 40, and a snap ring 43 for detachably fixing the spring receiving member 40 in the passage 35 It is. These members are arranged coaxially along the central axis CL of the first valve body 33 in the order described above from the distal end side of the housing 12, that is, the discharge nozzle 15 side. The coil spring 39 is incorporated with an initial deflection, and urges the second valve body 37 to press against the valve seat portion 36.

  A valve seat surface (also referred to as a seat surface) 36a for sealing a fluid by the second valve element 37 being seated is formed at a corner portion of the step which is the valve seat portion 36. The valve seat surface 36a is a partial conical surface. The function of the partially conical valve seat surface 36a is the same as that of the valve seat surface 16a of the valve seat ring 16 described above, and therefore the description thereof is omitted. When the second valve body 37 is seated on the valve seat surface 36a by the coil spring 39, the passage 35 is closed. In this state, the internal fluid does not flow out of the pump 2 and the fluid does not enter from the outside through the discharge nozzle 15. Of course, this action and effect is based on the premise that the first valve body 33 closes the discharge port 6a. However, since the internal pressure of the pump 2 is low, the discharge port 6a is formed by the first valve body 33. It is closed.

  When the dispenser 31 performs a normal discharge operation, the second valve body 37 is pressed against the valve seat portion 36 by the internal pressure of the pump 2 higher than the external pressure and the spring force of the second coil spring 39, and the passage 35 is opened. Closed. Therefore, the passage 35 does not affect the discharge function and the dripping prevention function as the dispenser described above.

  The spring force due to the initial deflection of the second coil spring 39 is smaller than the valve opening force applied to the second valve body 37 due to the differential pressure between the set suction pressure of the pump 2 and the external pressure (usually atmospheric pressure), and The valve opening force applied to the second valve element 37 is set to a value greater than the differential pressure between the internal pressure of the pump 2 and the external pressure when the pump 2 is stopped. Therefore, when the force due to the differential pressure applied to the second valve element 37 during the reverse rotation of the pump 2 overcomes the spring force of the coil spring 39, the second valve element 37 is sucked toward the pump 2 and the passage 35 is opened. The fluid remaining inside the housing 12 and the discharge nozzle 15 is sucked into the pump 2. Further, when the suction operation of the pump 2 is stopped and its internal pressure rises, and the force due to the differential pressure falls below the spring force of the coil spring 39, the second valve element 37 closes the passage 35 and leaks the internal fluid. Needless to say, external fluid including the atmosphere is prevented from flowing into the pump 2.

  In actual use, the spring force of the coil spring 39 is set to a small value. This is because when the discharge operation of the dispenser 31 stops, the pump 2 is instantaneously reversely rotated to perform a short-time suction operation and stop immediately. The residual fluid inside the housing 12 and the discharge nozzle 15 is sucked back by this short-time operation. Therefore, it is preferable to reduce the spring force for closing the passage 35.

  The inner periphery of the passage 35 has a configuration similar to the inner periphery of the housing 12 described above with reference to FIG. That is, as is apparent from FIG. 4, four protrusions 41 parallel to the axis CL direction are formed on the inner peripheral surface of the passage 35 every 90 ° in the circumferential direction. This protrusion 41 is for guiding the axial movement of the second valve element 37. Moreover, the partial cylindrical surface-shaped recess 42 between the protrusions 41 is for ensuring the flow path (second flow path) of the fluid sucked when the closing device 32 is opened. However, in the inner peripheral surface of the passage 35, the protrusion 41 and the recess 42 are not formed in the portion 35a to which the spring receiving member 40 and the snap ring 43 are attached, and is continuous with the inner peripheral surface of the protrusion 41. Are formed as inner peripheral surfaces having the same radius. This is to fit the spring receiving member 40 without play.

  The snap ring 43 is detachably fitted in a fitting groove 35 b formed in the circumferential direction on the inner circumferential surface of the passage 35. Further, the spring receiving member 40 has a central portion 40a opened to secure a second flow path. On the inner periphery of the central opening 40a, a step 40b is formed as a spring receiving portion on which the end of the coil spring 39 is seated. According to the above configuration, by removing the snap ring 43 from the fitting groove 35b, other mounting parts (the spring receiving member 40, the coil spring 39, the spring seat member 38, and the second valve body in the first valve body 33 are provided. 37) can be easily removed.

  Therefore, these parts can be replaced as needed. For example, when changing the setting of the suction pressure of the pump 2, the opening / closing pressure of the closing device 32 can be easily changed by changing to a coil spring having different characteristics. For example, a coil spring having a different spring constant may be changed, and its initial deflection may be changed. In that case, the spring seat member 38 and the spring bearing member 40 are also replaced with ones having different sizes and shapes in accordance with changes in the inner diameter and initial deflection of the coil spring.

  The dispensers 1 and 31 described above can be used in a fluid supply system as shown in FIG. That is, the dispensers 1 and 31 of the above embodiment can be used in place of the conventional dispenser 63 shown in FIG. In this case, during the operation of the system, the dispenser 1 and 31 is always supplied with pressurized fluid by a booster such as the high-pressure pump 62 provided in the supply line 64 regardless of whether or not the discharge operation is being performed. Has been. However, the above-described excellent functions of the dispensers 1 and 31 provide a fluid supply system that can effectively prevent liquid dripping from the discharge port.

  In the dispenser according to the present invention, when the fluid discharge operation is stopped, the discharge portion is closed and unnecessary fluid leakage from the discharge portion is prevented. Therefore, for example, in an automobile assembly plant, etc., leakage (liquid dripping) from the discharge part of the dispenser is severely restricted, such as a fluid supply system that supplies a high-viscosity fluid such as a sealant, grease, adhesive, etc. to a workpiece such as a car body. It is useful for the user who is using it.

Fig.1 (a) is a longitudinal cross-sectional view which shows the principal part of one Embodiment of the dispenser of this invention, FIG.1 (b) is the II sectional view taken on the line of Fig.1 (a). It is a perspective view before an assembly showing the interior parts of the dispenser of FIG. It is a partially cutaway perspective view which shows the housing of the closing device in the dispenser of FIG. Fig.4 (a) is a longitudinal cross-sectional view which shows the principal part of other embodiment of the dispenser of this invention, FIG.4 (b) is the IV-IV sectional view taken on the line of Fig.4 (a). It is a piping diagram showing an example of a fluid supply system to which the dispenser of the present invention can be applied. 6A is a longitudinal sectional view showing an example of a conventional dispenser, FIG. 6B is a sectional view taken along the line VIB-VIB of FIG. 6A, and FIG. 6C is a sectional view of FIG. Is a cross-sectional view taken along line VIC-VIC of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dispenser 2 Pump 3 Stator 3a (stator) end surface 4 Rotor 5 (Stator) inner hole 5a (Stator) volume part 6 (Pump) discharge part 6a (Pump) discharge port 7 O-ring 11 Closing device 12 Housing 12a (housing) base end portion 13 discharge hole 14 union nut 15 discharge nozzle 16 valve seat ring 16a valve seat surface 17 valve body 18 spring seat member 18a convex portion 18b concave portion 19 coil spring 20 spacer 21 ridge 21a ) End face 22 Recess 23 Spacer holding part 24 Arc-shaped notch part 25 Leg part 26 Step part 27 Valve seat holding part 28 First flow path 31 Dispenser 32 Closing device 33 (First) Valve body 34 Protruding part 35 Passage 35a (Passage) Snap ring mounting part 36 Valve seat part 36a Valve seat surface 37 Second valve body 38 Spring seat part Material 39 (second) coil spring 40 spring receiving member 40a opening 40b (spring receiving member) step 40b (spring receiving member) step 41 ridge 42 recess 43 snap ring

Claims (12)

A pump having a fluid discharge part;
An opening and closing device attached to the discharge part of the pump,
The closing device constitutes a first flow path that opens when the pressure of the internal fluid in the discharge section reaches a predetermined pressure, and through which the discharge fluid passes, and when the pressure drops below the predetermined pressure, A fluid ejection device configured to close.   In the state in which the first flow path is closed, the closing device opens when the fluid that is opened and sucked passes when the internal pressure of the pump becomes lower than the external pressure in the discharge portion by a predetermined differential pressure. The fluid ejection device according to claim 1, wherein two fluid passages are configured and the second fluid passage is closed when a differential pressure smaller than the differential pressure is reached.   A first valve body provided around the discharge port in the discharge unit; and a first valve body that closes the discharge port by seating on the first valve seat from the outside of the discharge port. And a first elastic member that urges the first valve body to press against the first valve seat. A first valve body provided around the discharge port in the discharge unit; and a first valve body that closes the discharge port by seating on the first valve seat from the outside of the discharge port. And a first elastic member that urges the first valve body to press against the first valve seat,
The first valve body is formed inside thereof, the second flow path communicating between the inside and the outside of the pump, the second valve seat formed in the second flow path, and the second A second valve body that closes the second flow path by seating on the valve seat from the inside of the second flow path, and a second valve body that urges the second valve body to be pressed against the second valve seat. The fluid ejection device according to claim 2, further comprising a second elastic member.   The fluid discharge device according to claim 3, wherein the first valve body is formed of a spherical body.   The fluid ejection device according to claim 4, wherein the second valve body is formed of a spherical body.   The fluid discharge device according to claim 5, wherein the first valve seat has a partial conical valve seat surface that is in contact with the first valve body and seals fluid.   The fluid discharge device according to claim 5, wherein the second valve seat has a partially conical valve seat surface that seals fluid in contact with the second valve body. The closing device has a housing that houses the first valve seat, the first valve body, and the first elastic member,
This housing has a fluid outlet and is detachably attached to the discharge part of the pump,
The fluid ejection device according to claim 3, wherein the first elastic member is configured to be exchangeable with an elastic member having different characteristics.   The second valve body and the second elastic member are detachably mounted in the second flow path of the first valve body, and the second elastic member is configured to be exchangeable with an elastic member having different characteristics. The fluid ejection device according to claim 4.   The pump includes a stator having an oval cross-section inner hole having two female screw shapes, and a perfect circular cross-section rotor that is spirally twisted into a male screw shape, and the rotor is an inner hole of the stator. The fluid discharge device according to claim 1, wherein the fluid discharge device is constituted by a uniaxial eccentric screw pump that is rotatably fitted in the shaft. A fluid ejection device according to any one of claims 1 to 11;
A fluid supply line for supplying fluid to the fluid ejection device;
A fluid supply system, comprising: a fluid pressurization device provided in the fluid supply line for pumping fluid toward the fluid discharge device.

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