JP5956960B2 - Pulsation prevention device - Google Patents

Description

  The present invention relates to a pulsation prevention device that prevents pulsation of a liquid.

  When applying a liquid from a liquid discharge tool to an object to be coated, the liquid contained in the container is supplied toward the liquid discharge tool by a pump. Examples of pump forms include a tube diaphragm type, a bellows type, a diaphragm type, and a piston type. As described in Patent Document 1, the tube diaphragm type is a pump using a tube that is elastically deformable in the radial direction as a pump member. As described in Patent Document 2, the bellows type is a pump that uses a bellows that can expand and contract in the axial direction as a pump member. If a diaphragm is used instead of the bellows, a diaphragm type pump is obtained. The piston type is a pump in which a pump chamber is expanded and contracted by a piston that linearly reciprocates in a cylinder, and is also called a syringe type.

  Such a pump is used, for example, in a liquid coating apparatus for coating a liquid such as a photoresist solution on the surface of a semiconductor wafer, a glass substrate for liquid crystal, or the like. Pumps are also used in liquid applicators that apply liquid to films, paper, and the like. Furthermore, also in the technical field which manufactures a battery, a solar cell, organic EL, a flexible display, etc., in order to apply | coat a liquid, the pump is used.

  Since the pressure and flow rate of the liquid discharged from the pump fluctuate, the liquid in the pipe that guides the liquid discharged from the pump to the object to be coated pulsates due to pressure fluctuation or the like. On the other hand, in order to increase the application accuracy of the liquid to the object to be applied, it is necessary to discharge a constant flow rate of liquid from the liquid discharge tool at a stable flow rate. In order to prevent the pulsation of the liquid flowing in the pipeline and increase the application accuracy, for example, a pulsation preventing device as described in Patent Document 3 is used.

JP 2010-380007 A JP 2009-138520 A Japanese Utility Model Publication No. 57-38987

  As described in Patent Document 3, as a pulsation preventing device, there are a piston type in which a piston is incorporated in a container and a diaphragm type in which a diaphragm is incorporated in a container. An expansion / contraction chamber communicating with the pipe line is formed by a piston and a diaphragm incorporated in the container. A spring force is applied to the piston and the diaphragm by a spring member in a direction to contract the expansion / contraction chamber. In the piston-type pulsation prevention device, since the piston is in sliding contact with the inner peripheral surface of the container, it is conceivable that wear powder generated by sliding is mixed into the liquid. On the other hand, the diaphragm-type pulsation prevention device has no sliding part, so that there is no possibility that the wear powder is mixed into the liquid.

  However, when a high pressure is applied to the diaphragm by the liquid, the diaphragm may be excessively elastically deformed against the spring force, and the diaphragm may be damaged or permanently deformed.

  The pulsation preventing device may be used for a plurality of types of liquid application devices having different liquid pressure conditions. For this reason, when an adjustment screw member for adjusting the spring force applied to the diaphragm is provided, the spring force applied to the diaphragm can be set within a range in which liquid pulsation is prevented. However, the diaphragm has a limited displacement range. In addition, since the ease (elasticity) of elastic deformation with respect to the displacement is not constant, it is necessary to set it within a range (optimum range) in which the effect of preventing pulsation is most easily exhibited. For example, if an excessive pressure is applied to the diaphragm with respect to the setting of the spring force, the diaphragm is out of the optimum range, and the diaphragm is difficult to elastically deform, and pulsation cannot be prevented. Similarly, when the setting of the spring force is excessive with respect to the pressure of the liquid, the diaphragm becomes a region in which elastic deformation is difficult and pulsation cannot be prevented.

  An object of the present invention is to provide a pulsation prevention device capable of observing from the outside whether a diaphragm is in an optimal elastic deformation range when preventing pulsation.

  The pulsation prevention device of the present invention is a pulsation prevention device that prevents pulsation of liquid, and reciprocates in the axial direction between an apparatus body in which a pulsation absorption chamber into which liquid flows is formed and a diaphragm that forms the pulsation absorption chamber. A case body that is movably accommodated, a spring member that is provided in the case body and that biases a spring force in a direction in which the pulsation absorbing chamber is contracted to the diaphragm, and is provided in the case body, A spring force adjusting member that adjusts the spring force of the spring member by changing the amount of elastic deformation, an actual position display unit that displays a position corresponding to the axial position of the diaphragm at a position away from the diaphragm, and a visual inspection from the outside An appropriate fluctuation range display unit that is provided in the case body freely and displays an appropriate fluctuation range of the diaphragm according to a pressure fluctuation of the pulsation absorption chamber.

  The diaphragm forming the pulsation absorbing chamber is elastically deformed, and the movement amount of the diaphragm corresponding to the elastic deformation amount is displayed on the actual position display unit. By comparing the positions of the actual position display section and the appropriate variation range provided in the case body, it is possible to observe from the outside whether or not the diaphragm is in the optimum elastic deformation range. By adjusting the spring force applied to the diaphragm, the diaphragm is elastically deformed within an appropriate range. Thereby, a high pulsation absorption effect is obtained.

It is sectional drawing which shows the pulsation prevention apparatus which is one embodiment of this invention. (A)-(C) are front views which show the change of the display part in the pulsation absorption state of the pulsation prevention apparatus shown in FIG. It is the schematic which shows the positional relationship of an actual position display part and the appropriate range edge part. It is a drag characteristic diagram showing the relationship between the axial displacement of the diaphragm and the drag. It is a front view which shows an example of the pump with which the pulsation prevention apparatus was mounted | worn. FIG. 6 is a sectional view taken along line 6-6 in FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 6. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 6. (A) shows the flow characteristics when the pulsation prevention device is used, and (B) shows the flow characteristics when the pulsation prevention device is not used. It is sectional drawing which shows the modification of a pulsation prevention apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the pulsation prevention device 10 has a port block 10a as a device main body. The port block 10a is provided with a primary side port 11 that communicates with the pump and a secondary side port 12 that communicates with the liquid ejection tool. Between the primary side port 11 and the secondary side port 12 of the port block 10a, the pulsation absorption chamber 13 which communicates with the flow path between the pump and the liquid discharger and into which the liquid flows is formed.

  When the port block 10a is directly attached to the pump, the primary side port 11 is connected to the discharge port of the pump, and when the liquid discharge tool is directly attached to the port block 10a, the secondary side port 12 has a liquid discharge tool. Mounted directly. On the other hand, when the pump and the port block 10a are connected by piping, the piping on the pump side is connected to the primary side port 11. When the port block 10a and the liquid discharger are connected by piping, the liquid discharger side piping is connected to the secondary side port 12. When pipes or the like are screwed to the ports 11 and 12, screw holes are formed in the ports 11 and 12, respectively. On the other hand, when the port block 10a is abutted against the pump and the pulsation prevention device 10 is attached to the pump by the screw member, the primary port 11 is not formed with a screw hole. Also about the secondary side port 12, a screw hole is not formed depending on the attachment form of a liquid discharge tool.

  As shown in FIG. 1, a case body 14 is attached to the port block 10a as the apparatus main body. The case body 14 is formed of a cylindrical member, and an opening 15 is formed at one end, and an end wall 16 is provided at the other end. A flange 17 projecting radially outward is provided at one end of the case body 14. The fixing plate 18 that is abutted against the flange 17 is fastened to the port block 10 a by a fastening screw 19. The case body 14 is fastened to the port block 10 a by a fixing plate 18.

  The opening 15 of the case body 14 is provided with a diaphragm 21 for forming the pulsation absorption chamber 13. The diaphragm 21 includes a connecting portion 21a at a radial center portion, a fixing portion 21b at a radially outer peripheral portion, and an elastic deformation portion 21c therebetween. The fixed portion 21b of the diaphragm 21 is tightened between the port block 10a and the case body 14, and the diaphragm 21 is attached to the port block 10a. A reciprocating member 22 is mounted in the case body 14 so as to freely reciprocate in the axial direction. The reciprocating member 22 has a piston shape and includes a cylindrical portion 22a and an end wall portion 22b provided at one end portion, and the other end portion of the cylindrical portion is opened. A screw hole 23 is provided in the end wall portion 22 b of the reciprocating member 22, and a male screw portion 24 provided in the connecting portion 21 a of the diaphragm 21 is screwed to the screw hole 23.

  A compression coil spring 25 is mounted in the case body 14 as a spring member for biasing the spring force in a direction in which the pulsation absorbing chamber 13 is contracted with respect to the diaphragm 21. A spring force adjusting member 26 is attached to the end wall portion 16 of the case body 14 in order to adjust the amount of elastic deformation of the compression coil spring 25. The spring force adjusting member 26 has a male screw portion 26a that is screwed into a screw hole 27 provided in the end wall portion 16, and a spring receiving portion 26b provided in the one end portion. One end of the compression coil spring 25 is abutted against the end wall portion 22b of the reciprocating member 22, and the other end is abutted against the spring receiving portion 26b. A knob portion, that is, an operation portion 26c is provided at the other end portion of the male screw portion 26a. When the spring force adjusting member 26 is rotated by operating the operating portion 26c, the amount of elastic deformation in the axial direction of the compression coil spring 25 is adjusted.

  When the operation portion 26c is rotated in one direction to shorten the distance between the end wall portion 22b and the spring receiving portion 26b, the compression coil spring 25 is elastically deformed so as to contract in the axial direction. Thereby, the spring force applied to the diaphragm 21 via the reciprocating member 22 is adjusted so as to become stronger. On the other hand, when the operation portion 26c is rotated in the reverse direction to increase the distance between the end wall portion 22b and the spring receiving portion 26b, the compression coil spring 25 is elastically deformed so as to extend in the axial direction. Thereby, the spring force applied to the diaphragm 21 via the reciprocating member 22 is adjusted to be weak. A lock nut 28 is screwed to the male screw portion 26a. When the lock nut 28 is fastened to the case body 14, the spring force adjusting member 26 is prevented from rotating.

  In order to guide the reciprocating motion of the reciprocating member 22 in the axial direction, a guide groove 29 extending in the axial direction is formed in the cylindrical portion 22 a of the reciprocating member 22, and a guide pin 30 entering the guide groove 29 is formed in the case body 14. Is provided. Thereby, the reciprocating member 22 moves in the axial direction without rotating.

  When the reciprocating member 22 moves forward toward the pulsation absorption chamber 13 by the spring force, the pulsation absorption chamber 13 is contracted. On the other hand, when the reciprocating member 22 moves backward against the spring force by the pressure of the liquid in the pulsation absorption chamber 13, the pulsation absorption chamber 13 expands. Therefore, when the pressure of the liquid supplied from the pump to the pulsation absorption chamber 13 is increased, the diaphragm 21 is elastically deformed in the direction in which the pulsation absorption chamber 13 is expanded, and the pressure increase in the pulsation absorption chamber 13 is prevented. On the other hand, when the pressure of the liquid supplied into the pulsation absorption chamber 13 is lowered, the diaphragm 21 is elastically deformed in a direction in which the pulsation absorption chamber 13 is contracted, and the pressure drop in the pulsation absorption chamber 13 is prevented. As described above, when the pressure of the liquid supplied into the pulsation absorption chamber 13 is changed, the pressure fluctuation in the pulsation absorption chamber 13 is absorbed by the elastic deformation of the diaphragm 21, so that the liquid is discharged from the secondary side port 12. The pressure of the liquid is adjusted to a constant pressure.

  An expansion restricting stopper 31 is provided on the case body 14 to restrict excessively elastic deformation of the diaphragm 21 when the pulsation absorbing chamber 13 is expanded by the pressure of the liquid. The expansion regulating stopper 31 is formed by a stepped portion formed in the case body 14 and regulates the position of the diaphragm 21 when the pulsation absorbing chamber 13 reaches the expansion limit. When the end surface on the opening side of the reciprocating member 22 contacts the stopper 31 formed of a stepped portion, the movement of the reciprocating member 22 is restricted. This prevents the diaphragm 21 from being elastically deformed excessively in the direction in which the pulsation absorbing chamber 13 is expanded.

  In order to restrict the diaphragm 21 from being excessively elastically deformed when the pulsation absorbing chamber 13 is contracted by a spring force due to a decrease in the liquid pressure, a shrinkage restricting stopper 32 is provided on the case body 14. . The stopper 32 for restricting contraction is formed by an annular or rod-like member provided so as to protrude from the inner peripheral surface of the case body 14, and the position of the diaphragm 21 when the pulsation absorbing chamber 13 reaches the contraction limit. regulate. When the end surface on the end wall portion side of the reciprocating member 22 contacts the stopper 32, the movement of the reciprocating member 22 is restricted. This prevents the diaphragm 21 from being elastically deformed excessively in the direction in which the pulsation absorbing chamber 13 is contracted.

  The case body 14 is provided with a window 33 that is shifted in the circumferential direction with respect to the guide pin 30. The window 33 is provided to allow a part of the cylindrical portion 22a of the reciprocating member 22 to be visually observed. In the cylindrical portion 22a, an actual position display portion 34 is provided so as to be exposed to the window portion 33. Thereby, the actual position display unit 34 is visible from the outside of the case body 14. The actual position display unit 34 moves away from the diaphragm 21 at a position corresponding to the actual position of the diaphragm 21 in a state where the pulsation preventing device 10 is actually used and liquid is supplied to the pulsation absorbing chamber 13. Display by position. The actual position display portion 34 is formed by providing a V-shaped recess, that is, a V notch on the outer peripheral surface of the cylindrical portion 22a. However, as the actual position display part 34, instead of the V notch, a convex part may be provided on the cylindrical part 22a, or a mark of a color different from that of the cylindrical part 22a may be provided on the cylindrical part 22a.

  A transparent cover 35 is wound around the case body 14, and the window 33 is covered with the transparent cover 35. The actual position display unit 34 is visually observed from the outside through the cover 35. In order to display the proper fluctuation range 38 of the diaphragm 21 when the pulsation preventing device 10 is actually used and the pulsation absorbing chamber 13 is expanded, the appropriate range end 36 on the expansion side is formed on the inner surface of the transparent cover 35. Is provided. The proper range end 36 corresponds to the boundary value on the expansion side of the proper variation range 38 of the diaphragm 21 when the pulsation absorbing chamber 13 is expanded.

  Furthermore, in order to display the proper variation range 38 of the diaphragm 21 when the pulsation preventing device 10 is actually used and the pulsation absorbing chamber 13 contracts, the proper range end 37 on the contraction side is formed of the transparent cover 35. It is provided on the inner surface. The appropriate range end portion 37 corresponds to the boundary value on the contraction side of the appropriate variation range 38 of the diaphragm 21 when the pulsation absorbing chamber 13 contracts.

  The appropriate range end portions 36 and 37 are formed by providing a V-shaped convex portion on the inner surface of the cover 35 as a transparent portion, and the proper variation range is between the appropriate range end portions 36 and 37. 38. However, as the appropriate range end portions 36 and 37, a convex portion may be provided on the outer surface of the cover 35, or a concave portion may be provided on the cover 35 instead of the convex portion. As described above, the appropriate range end portions 36 and 37 may be formed by concavo-convex portions similarly to the actual position display portion 34, and a mark having a color different from that of the cylindrical portion 22a is formed on the inner surface or the outer surface of the cover 35. It may be applied.

  FIG. 3 is a schematic diagram showing the positional relationship between the actual position display unit 34 and the appropriate range end portions 36 and 37. FIG. 4 is a drag characteristic diagram showing the relationship between the axial displacement of the diaphragm 21 and the drag. As shown in FIG. 3, when the actual position display unit 34 moves in the proper variation range 38 between the appropriate range end 36 on the expansion side and the proper range end 37 on the contraction side, as shown in FIG. 4. The elastic deformation region of the diaphragm 21 is a low drag region. In FIG. 4, the symbol S indicates a low drag region.

  When the actual position display unit 34 is in the middle position of the low drag region S, no pressure or force is applied to the diaphragm 21. At this time, the actual position display unit 34 is in a neutral position or a free position. By adjusting the compression amount (spring force) of the compression coil spring 25 by rotating the operation portion 26c, a force that opposes the average pressure of the pulsation absorbing chamber 13 is applied to the diaphragm 21, so that the diaphragm 21 is in a neutral position, It can be positioned as close as possible to the free position.

  If the diaphragm 21 expands beyond the position regulated by the expansion regulating stopper 31, the diaphragm 21 may be permanently deformed or damaged. Therefore, the limit position on the expansion side of the diaphragm 21 is regulated by the stopper 31. Similarly, if the diaphragm 21 contracts beyond the position regulated by the shrinkage restricting stopper 32, the diaphragm 21 may be permanently deformed or damaged. Therefore, the limit position on the contraction side of the diaphragm 21 is regulated by the stopper 31. Assuming that the movement stroke of the actual position display section 34 in the appropriate variation range 38 is S, the distance T between both stoppers 31 and 32 is set to be larger than the stroke S. Thus, when the diaphragm 21 deforms beyond the low drag region in the expansion direction, the expansion limit position is regulated by the stopper 31. When the diaphragm 21 is deformed beyond the low drag region in the contraction direction, the contraction side limit position is regulated by the stopper 32.

  FIG. 2A shows a state where the actual position display unit 34 is at an intermediate position within the appropriate variation range 38. FIG. 2B shows a state in which the actual position display unit 34 has approached the appropriate range end 36 on the expansion side. FIG. 2C shows a state in which the actual position display unit 34 has approached the appropriate range end 37 on the contraction side.

  As shown in FIG. 2, when the actual position indicator 34 is operating while being positioned between both appropriate range ends 36 and 37, that is, in the proper variation range 38 of the stroke S in FIGS. When the diaphragm 21 is moving, the diaphragm 21 is deformed and moved in response to a slight pressure fluctuation in the pulsation absorbing chamber 13. That is, the diaphragm 21 moves lightly, and an optimum pulsation absorbing function can be obtained by the diaphragm 21. On the other hand, when trying to operate the diaphragm 21 beyond the appropriate fluctuation range 38, it does not respond to the pressure of the pulsation absorption chamber 13 applied to the diaphragm 21. That is, even when the pressure of the pulsation absorbing chamber 13 applied to the diaphragm 21 increases or contracts, the deformation amount of the diaphragm 21 is very small. That is, the diaphragm 21 cannot obtain an optimal pulsation absorbing function. Since the diaphragm 21 is restricted by the stoppers 31 and 32 from being deformed excessively, there is no possibility that permanent deformation or cracking will occur in the diaphragm 21. Thereby, the durability of the diaphragm 21 can be improved.

  When the actual position display unit 34 moves to a position exceeding the appropriate range end 36 on the expansion side with the liquid supplied into the pulsation absorption chamber 13, the lock nut 28 is loosened and the operation unit 26c is moved. The compression coil spring 25 is displaced in the contraction direction by rotating. Thereby, the spring force applied to the diaphragm 21 by the compression coil spring 25 via the reciprocating member 22 is strengthened. When the spring force is strengthened, the elastic deformation range of the diaphragm 21 for absorbing the pulsation does not exceed the position of the appropriate range end 36 and elastically deforms. Thus, if the diaphragm 21 can be operated within an appropriate elastic deformation operating range, the diaphragm 21 is operated within a range in which pulsation is reliably prevented, and the pulsation absorbing effect can be enhanced.

  When the actual position display unit 34 moves to a position exceeding the appropriate range end 37 on the contraction side in a state where the liquid is supplied into the pulsation absorption chamber 13, the operation unit 26c is operated in the direction opposite to the above. Is done. Thereby, the spring force applied to the diaphragm 21 by the compression coil spring 25 via the reciprocating member 22 is weakened. When the spring force is weakened, the elastic deformation range of the diaphragm 21 for absorbing pulsation does not exceed the position of the appropriate range end 37 and elastically deforms. When the liquid pressure applied to the diaphragm 21 becomes excessively high, the reciprocating member 22 contacts the stopper 31. On the other hand, when the liquid pressure applied to the diaphragm 21 is excessively low, and when no liquid is supplied into the pulsation absorbing chamber 13, the reciprocating member 22 contacts the stopper 32. Thereby, it is possible to prevent an excessive external force from being applied to the diaphragm 21, and the diaphragm 21 can be improved in durability without causing permanent deformation.

  The pulsation prevention device 10 is used to prevent pulsation of liquid in a pipe forming a liquid supply circuit. For example, when this pulsation prevention device 10 is used in a liquid supply circuit for supplying liquid discharged from a pump to a liquid discharge tool, even if pulsation occurs in the liquid discharged from the pump, the pulsation is reduced. The liquid can be absorbed and supplied at a constant flow rate to the liquid ejection tool.

  The spring force applied to the diaphragm 21 can be adjusted according to the pressure of the liquid flowing in the pipe. The spring force is adjusted by adjusting the appropriate fluctuation range 38 for absorbing pulsation by the spring force adjusting member 26 in the initial setting stage of the pulsation preventing device 10 or in a state where liquid is actually supplied into the pipe. can do. Thus, the diaphragm 21 can be set in the appropriate fluctuation range 38 that can reliably prevent pulsation according to the pressure of the liquid in the liquid supply circuit in which the pulsation prevention device 10 is used.

  5-8 shows the pump 41 provided with the pulsation prevention apparatus 10 mentioned above. The pump 41 has a pump block 42. As shown in FIG. 7, the pump block 42 is provided with two tubes 43a and 43b that are elastically deformed in the radial direction as pump members. The pump 41 is a twin-type tube frame type. . The tubes 43a and 43b are partitioned into inner pump chambers 44a and 44b and outer drive chambers 45a and 45b. The tubes 43a and 43b serve as partition members for partitioning the pump chamber and the drive chamber. Yes.

  A supply block 46 is provided at one end of the pump block 42, and a pipe 48 is connected to a supply port 47 provided in the supply block 46 as shown in FIG. 6. . The pipe 48 is connected to the liquid storage tank 49, and the liquid L in the liquid storage tank 49 is guided to the supply port 47 through the pipe 48. As shown in FIG. 7, the supply block 46 is provided with flow paths 47a and 47b branched into two from the supply port 47. The flow path 47a communicates with the pump chamber 44a, and the flow path 47b It communicates with the pump chamber 44b.

  The above-described pulsation prevention device 10 is attached to the other end of the pump block 42. As shown in FIG. 7, the port block 10a of the pulsation preventing device 10 is provided with a primary side port 11a communicating with the pump chamber 44a and a primary side port 11b communicating with the pump chamber 44b. Each primary side port 11 a, 11 b communicates with the pulsation absorbing chamber 13. In the pulsation prevention device 10 shown in FIG. 1, only one primary side port 11 is shown. However, when the pulsation prevention device 10 is provided in the pump 41 having two pump members, the pulsation prevention device 10 is provided with two primary ports 11a and 11b. Note that when the pulsation prevention device 10 supplies liquid discharged from one pump member to the liquid ejection tool, the pulsation prevention device 10 has only one primary port.

  When the drive medium M is supplied to the drive chambers 45a and 45b, the tubes 43a and 43b contract in the radial direction, and the pump chambers 44a and 44b contract. On the other hand, when the drive medium M in the drive chambers 45a and 45b is discharged to the outside, the tubes 43a and 43b expand in the radial direction and the pump chambers 44a and 44b expand. Check valves 51a and 52a are provided in both ends of the tube 43a, and check valves 51b and 52b are provided in both ends of the tube 43b. When the tube 43a contracts, the check valve 51a closes the pump chamber 44a, the check valve 52a opens the pump chamber 44a, and the liquid L in the pump chamber 44a is supplied to the pulsation absorbing chamber 13. Conversely, when the tube 43a expands, the check valve 51a is opened, the check valve 52a is closed, and the liquid in the liquid storage tank 49 is supplied into the pump chamber 44a.

  Similarly, when the tube 43b contracts, the check valve 51b closes the pump chamber 44b, the check valve 52b opens the pump chamber 44b, and the liquid L in the pump chamber 44b is supplied to the pulsation absorbing chamber 13. Conversely, when the tube 43b expands, the check valve 51b is opened, the check valve 52b is closed, and the liquid in the liquid storage tank 49 is supplied into the pump chamber 44b. Therefore, when the pump chambers 44a and 44b are alternately expanded and contracted, the liquid L is continuously supplied to the pulsation absorption chamber 13 of the pulsation prevention device 10.

  The liquid supplied to the pulsation absorption chamber 13 becomes a constant pressure as the pressure fluctuation of the liquid is absorbed in the pulsation absorption chamber 13 by the elastic deformation of the diaphragm 21. As shown in FIG. 6, the liquid having a constant pressure is supplied to the liquid ejection tool 54 through the pipe 53 connected to the secondary side port 12, and the liquid is directed from the liquid ejection tool 54 toward the application object. Applied.

  In order to expand and contract the pump chambers 44a and 44b alternately, the pump block 42 is provided with two cylinder holes 55a and 55b. Pistons 56a and 56b are provided in the respective cylinder holes 55a and 55b so as to be capable of reciprocating in the axial direction. The front end surfaces of the pistons 56a and 56b form part of the drive chambers 45a and 45b. . Therefore, when one of the two pistons 56a and 56b is moved forward toward the pump chamber and the other is moved backward in the direction away from the pump chamber, the pump chambers 44a and 44b are alternately expanded and contracted, and the pump operation is performed. .

  As shown in FIG. 8, a drive block 57 is attached to the pump block 42. Drive rods 58a and 58b coaxial with the pistons 56a and 56b are mounted on the drive block 57 so as to be reciprocally movable in the axial direction. Protrusions 59a and 59b provided on pistons 56a and 56b are inserted into recesses provided on one end of each drive rod 58a and 58b. A cam member 62 is disposed in the cam housing chamber 61 formed in the drive block 57, and the cam member 62 has a cam shaft 62a and a cam panel 62b.

  A motor 64 is attached to the drive block 57 via a connection block 63. A cam shaft 62 a is connected to the main shaft 65 of the motor 64 via a joint 66, and the cam member 62 is rotationally driven by the motor 64. Each of the drive rods 58a and 58b is provided with drive rollers 68a and 68b that come into contact with the cam surface 67 of the cam board 62b. The respective drive rollers 68a and 68b are pressed against the cam surface 67 by the spring force of the compression coil springs 60a and 60b provided on the pistons 56a and 56b.

  As shown in FIG. 6, the cam surface 67 is an inclined surface. When the cam shaft 62 a is rotationally driven by the motor 64, the drive rollers 68 a and 68 b roll along the cam surface 67. In the half cycle of the rotation of the cam shaft 62a, one drive rod is driven forward and the other drive rod is driven backward. In the latter half cycle, one drive rod is driven backward and the other drive rod is driven forward. FIG. 8 shows a state in which the drive rods 58a and 58b are in the center of the reciprocating stroke in the axial direction. Under this condition, when the cam shaft 62a rotates, one drive rod is driven forward and the other drive rod is driven backward.

  When the drive rod 58a is driven forward, the tube 43a contracts and the liquid in the pump chamber 44a is discharged to the pulsation absorbing chamber 13 through the check valve 52a. At this time, the drive rod 58b is driven backward to expand the tube 43b. Thereby, the liquid in the liquid storage tank 49 is sucked into the pump chamber 44b through the check valve 51b. Accordingly, when the cam shaft 62a is continuously rotated, the two drive rods 58a and 58b are continuously driven in opposite directions, that is, in opposite phases. As a result, the liquid L is continuously supplied into the pulsation absorption chamber 13, and the liquid L is continuously supplied from the pulsation absorption chamber 13 to the liquid ejection tool 54.

  Thus, when the two pump members are alternately expanded and contracted, pulsation of the liquid discharged from both pump members may occur, but the diaphragm 21 forming the pulsation absorption chamber 13 is elastically deformed, Pulsation is eliminated.

  9 shows a pulsation occurrence state in the liquid supply circuit in which liquid is supplied to the liquid discharger 54 using the pump 41 shown in FIGS. It is a flow rate characteristic diagram of a pump shown in comparison with the case where there is no.

  FIG. 9A shows the flow characteristics when the pulsation prevention device 10 is used, and FIG. 9B shows the flow characteristics when the pulsation prevention device 10 is not used. As shown in FIG. 9B, in the twin type pump using two pump members, when switching from the liquid discharge due to the contraction of one tube to the liquid discharge due to the contraction of the other tube, a large Generation of pulsation was observed. On the other hand, as shown in FIG. 9A, when the pulsation prevention device 10 is provided in the liquid supply circuit, no pulsation occurs in the flow path from the pump discharge port to the liquid discharge tool, and a constant flow rate is obtained. The liquid could be applied to the member to be coated. If the application amount of the liquid to the application object is set by the application time, pulsation does not occur. Therefore, by setting the application time, a fixed amount of liquid can be applied to the application object with high accuracy.

  Therefore, when a medicine is applied to the film, the medicine is applied from the liquid ejection tool 54. When a drug is applied to the film, if a pulsation is generated in the drug discharged from the liquid discharge tool 54, the film thickness is not uniform and uneven coating occurs. On the other hand, when the pulsation preventing device 10 is used, a highly accurate uniform film thickness drug can be applied to the film.

  When the flow rate of the liquid discharged from the pump 41 changes, the discharge pressure also changes. Also, if the liquid has different viscosities, the discharge pressure will be different even if the discharge flow rate from the pump is the same. On the other hand, according to the pressure of the pulsation absorption chamber 13, the spring force urged by the diaphragm 21 can be adjusted so that the diaphragm 21 operates optimally. In addition, it can be easily observed from the outside whether or not the diaphragm 21 is in an optimum operating state.

  FIG. 10 is a cross-sectional view showing a modified example of the pulsation preventing device 10, and in FIG. 10, members that are the same as those shown in FIG.

  In the pulsation prevention device 10 shown in FIG. 1, a diaphragm 21 formed by a member different from the reciprocation member 22 is provided in the reciprocation member 22, whereas in the pulsation prevention device 10 shown in FIG. The diaphragm 21 is provided integrally with the reciprocating member 22. A stopper 32 a for restricting contraction of the diaphragm 21 is formed by a rod-like member such as a pin, and this stopper 32 a is attached to the case body 14. Except for these structures in FIG. 10, the other structures are the same as those shown in FIG.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, as the form of the pump 41, not only a tube diaphragm type as shown, but also a bellows type, a diaphragm type, a piston type, and the like can be used. The illustrated pump 41 is a twin type having two pump members. However, the pulsation preventing device 10 is also applied to a liquid supply circuit using one pump member or a pump having three or more pump members. Can be applied.

DESCRIPTION OF SYMBOLS 10 Pulsation prevention apparatus 10a Port block 11, 11a, 11b Primary side port 12 Secondary side port 13 Pulsation absorption chamber 14 Case body 21 Diaphragm 22 Reciprocating member 22a Cylindrical part 22b End wall part 25 Compression coil spring 26 Spring force adjustment member 31 Stopper 32 Stopper 33 Window portion 34 Actual position display portion 35 Cover 36 Appropriate range end portion 37 on expansion side Appropriate range end portion 38 on contraction side Appropriate variation range 41 Pump 42 Pump blocks 43a and 43b Tubes 44a and 44b Pump chambers 45a and 45b Drive chamber 49 Liquid storage tank 54 Liquid discharge tool 62 Cam member 64 Motor

Claims (6)

A pulsation prevention device for preventing pulsation of liquid,
An apparatus body in which a pulsation absorption chamber into which liquid flows is formed;
A case body that accommodates the diaphragm forming the pulsation absorbing chamber in a reciprocating manner in the axial direction;
A spring member that is provided in the case body and biases a spring force in a direction in which the pulsation absorbing chamber is contracted to the diaphragm;
A spring force adjusting member that is provided on the case body and adjusts a spring force of the spring member by changing an elastic deformation amount of the spring member;
An actual position display unit for displaying a position corresponding to the axial position of the diaphragm at a position away from the diaphragm;
An appropriate variation range display unit that is provided in the case body so as to be visible from the outside, and displays an appropriate variation range of the diaphragm according to a pressure variation of the pulsation absorption chamber;
An anti-pulsation device having   The pulsation prevention device according to claim 1, wherein when the diaphragm is elastically deformed beyond the appropriate variation range due to expansion of the pulsation absorbing chamber, an expansion restriction stopper for restricting elastic deformation on the expansion side of the diaphragm; A pulsation prevention provided on the case body with a shrinkage restricting stopper for restricting elastic deformation on the contraction side of the diaphragm when the diaphragm is elastically deformed beyond the appropriate fluctuation range due to contraction of the pulsation absorbing chamber. apparatus.   The pulsation prevention device according to claim 1 or 2, wherein the case body is provided with a reciprocating member that can reciprocate in the axial direction, and the diaphragm and the actual position display unit are provided on the reciprocating member. . The pulsation prevention device according to claim 3,
The actual position display unit is a pulsation prevention device, which is a concavo-convex part provided on an outer surface of the reciprocating member or a mark made of a color different from the outer surface.   The pulsation prevention device according to any one of claims 1 to 4, wherein a window portion for visually observing the actual position display portion is provided in the case body, and a transparent cover that covers the window portion is provided as the appropriate amount. A pulsation prevention device that uses a fluctuation range display.   6. The pulsation prevention device according to claim 5, wherein the appropriate variation range display unit is formed by an uneven portion or a mark provided on the cover.

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