Liquid feeding device and inkjet recording apparatus

Abstract

To provide a liquid feeding device which suppresses deterioration in quality of a liquid discharged from a diaphragm pump or achieves improvement of the quality of the liquid.SOLUTION: An ink feeding device 20 includes a diaphragm pump 21, a suction unit 22, a discharge unit 23, and filter units 24A, 24B. The suction unit 22 and the discharge unit 23 are arranged in a stacking manner so that an inflow chamber 222 and an outflow chamber 232 for an ink face a diaphragm 213 on one side in a reciprocating direction of the diaphragm 213 with the filter units 24A, 24B sandwiched therebetween. The suction unit 22, the discharge unit 23, and the filter units 24A, 24B unit are attachable to and detachable from each other.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a liquid supplying device and an inkjet recording apparatus. [Background technology]

[0002] Inkjet recording devices, which eject ink onto a recording medium such as paper to record an image, are widely used as recording devices such as printers and copiers because they can record high-definition images. In such inkjet recording devices, a pump transports ink from an ink container that contains the ink to a recording head that ejects the ink onto the recording medium. A diaphragm pump is known as such a pump.

[0003] For example, a conventional diaphragm pump disclosed in Patent Document 1 includes a pump chamber and a diaphragm provided in the pump chamber. An inlet and an outlet for liquid are connected to the internal space of the pump chamber. The diaphragm reciprocates to increase and decrease the volume of the internal space of the pump chamber. As a result, the liquid flows into the internal space of the pump chamber through the inlet and flows out of the internal space of the pump chamber through the outlet, and is transported. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-23436 A Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional diaphragm pumps have an issue in that they do not take into consideration the prevention of deterioration of the liquid flowing into the internal space of the pump chamber and flowing toward the outlet, or the improvement of the liquid quality. As a result, there is concern that the conventional technology may cause problems such as a decrease in the pump's performance in transporting the liquid.

[0006] The present invention has been made in consideration of the above-mentioned points, and aims to provide a liquid supply device and an inkjet recording device that can suppress deterioration of the quality of the liquid ejected from a diaphragm pump or improve the quality of the liquid. [Means for solving the problem]

[0007] In order to solve the above problems, the liquid supply device of the present invention includes a diaphragm pump, a suction unit, a discharge unit, and an optional unit. The diaphragm pump transports liquid by reciprocating movement of a diaphragm. The suction unit has a suction check valve that allows the liquid to flow only in the suction direction relative to the diaphragm, and an inflow chamber into which the liquid flows via the suction check valve. The discharge unit has a discharge check valve that allows the liquid to flow only in the discharge direction relative to the diaphragm, and an outflow chamber from which the liquid that flows in from the inflow chamber flows out toward the discharge check valve. The optional unit is disposed between the suction unit and the discharge unit. The suction unit and the discharge unit are disposed overlapping with each other, with at least one optional unit sandwiched therebetween, so that the inflow chamber and the outflow chamber face the diaphragm on one side of the reciprocating direction of the diaphragm. The suction unit, the discharge unit, and the optional unit are detachable from each other. Effect of the Invention

[0008] According to the configuration of the present invention, an optional unit is disposed upstream in the liquid flow direction of the discharge unit on the liquid discharge side relative to the diaphragm. The optional unit can be configured to perform various treatments on the flowing liquid. Therefore, it is possible to prevent deterioration of the liquid discharged from the diaphragm pump or to improve the quality of the liquid. [Brief description of the drawings]

[0009] [Figure 1]1 is a schematic sectional front view of an inkjet recording apparatus according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a plan view of the periphery of a recording unit of the inkjet recording apparatus of FIG. [Diagram 3] 2 is an explanatory diagram showing the configuration of a control system and an ink supply system in the periphery of a printing unit of the inkjet printing apparatus of FIG. [Figure 4] FIG. 4 is a front view of the ink supply device of FIG. [Diagram 5] FIG. 4 is a top view of the ink supply device of FIG. [Figure 6] FIG. 4 is a side view of the ink supply device of FIG. [Figure 7] FIG. 4 is a perspective view of the ink supply device of FIG. [Figure 8] 7 is a vertical cross-sectional side view of the ink supply device of FIG. 6. [Figure 9] 9 is a vertical cross-sectional side view of the ink supply device of FIG. 8, showing a state in which the components are disassembled. [Figure 10] 9 is a vertical cross-sectional side view of a discharge unit of the ink supply device of FIG. 8. [Figure 11] 9 is a vertical cross-sectional side view of a suction unit of the ink supply device of FIG. 8. [Figure 12] 9 is a vertical cross-sectional side view of a filter unit of the ink supply device of FIG. 8. [Figure 13] FIG. 13 is a top view of the filter unit of FIG. 12. [Figure 14] FIG. 13 is a top view of the filter unit of FIG. 12 with the filter removed. [Figure 15] FIG. 13 is a top view of the option unit of the first modified example. [Figure 16] FIG. 11 is a top view of an option unit according to the second modified example. [Figure 17] 7 is a perspective view of a plate-shaped member of the ink supply device of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following.

[0011] Fig. 1 is a schematic cross-sectional front view of an inkjet recording device 1 of an embodiment. Fig. 2 is a plan view of the periphery of a recording unit 5 of the inkjet recording device 1 of Fig. 1. The inkjet recording device 1 is, for example, an inkjet recording printer. As shown in Figs. 1 and 2, the inkjet recording device 1 includes a device main body 2, a paper supply unit 3, a paper transport unit 4, a recording unit 5, a drying unit 6, a paper discharge unit 7, and a control unit 8.

[0012] The paper supply unit 3 is disposed, for example, at the bottom of the device main body 2. The paper supply unit 3 stores a plurality of sheets of paper (recording media) S, and separates and sends out the sheets of paper S one by one during recording.

[0013] The paper transport section 4 is disposed downstream of the paper supply section 3 in the paper transport direction, and transports the paper S sent out from the paper supply section 3. The paper transport section 4 transports the paper S to the recording section 5 and drying section 6, and then discharges the paper S after recording and drying to the paper discharge section 7. The paper transport section 4 has, for example, a reversing transport section 4r. When double-sided recording is performed, the paper transport section 4 distributes the paper S after recording and drying on the first side to the reversing transport section 4r, and then switches the transport direction to revert the paper S and transport it again to the recording section 5 and drying section 6.

[0014] The paper conveying section 4 includes a first belt conveying section 41 and a second belt conveying section 42. The first belt conveying section 41 has a first conveying belt 411 formed in an endless shape. The second belt conveying section 42 has a second conveying belt 421 formed in an endless shape. The first belt conveying section 41 and the second belt conveying section 42 adsorb and hold the paper S on the outer surface (upper surface) of the upper side of the first conveying belt 411 and the second conveying belt 421, respectively, and convey the paper S. The first belt conveying section 41 is disposed below the recording section 5 and conveys the paper S. The second belt conveying section 42 is disposed downstream of the first belt conveying section 41 in the paper conveying direction, and is disposed in the drying section 6 and conveys the paper S.

[0015] The recording unit 5 is located downstream of the paper supply unit 3 in the paper conveying direction, and is disposed opposite the first belt conveying unit 41. The recording unit 5 faces the paper S that is adsorbed and held on the upper surface of the first conveying belt 411 and conveyed, and is disposed above the first conveying belt 411 with a predetermined gap therebetween. In other words, the recording unit 5 faces the paper S conveyed by the paper conveying unit 4.

[0016] 2, the recording unit 5 holds head units 51B, 51C, 51M, and 51Y corresponding to the four colors of black, cyan, magenta, and yellow, respectively. The head units 51B, 51C, 51M, and 51Y are arranged side by side along the paper transport direction Dc so that their longitudinal directions are parallel to the paper width direction Dw that is perpendicular to the paper transport direction Dc. Note that the four head units 51B, 51C, 51M, and 51Y have the same basic configuration, so in the following explanation, the identification symbols "B", "C", "M", and "Y" representing each color may be omitted unless there is a particular need to limit them.

[0017] Each of the head units 51 for each color has a line-type inkjet recording head 52. In each of the head units 51 for each color, a plurality of recording heads 52 (for example, three (52a, 52b, 52c)) are arranged in a staggered pattern along the paper width direction Dw.

[0018] The recording head 52 has a plurality of ink ejection nozzles 521 at its bottom. The plurality of ink ejection nozzles 521 are arranged in a row along the paper width direction Dw, and can eject ink over the entire recording area on the paper S. That is, the recording head 52 has a plurality of ink ejection nozzles 521 that eject ink onto the paper S. The recording unit 5 sequentially ejects ink from each of the recording heads 52 of the four color head units 51B, 51C, 51M, and 51Y toward the paper S transported by the first transport belt 411, and records a full-color image or a monochrome image on the paper S.

[0019] The drying unit 6 is disposed downstream of the recording unit 5 in the paper transport direction, and is provided with a second belt transport unit 42. The paper S on which an ink image has been recorded in the recording unit 5 is adsorbed and held by the second transport belt 421 in the drying unit 6, during which the ink is dried while being transported. The dried paper S is discharged to the paper discharge unit 7.

[0020] The control unit 8 includes a CPU, a memory unit, and other electronic circuits and electronic components (all not shown). The CPU controls the operation of each component provided in the inkjet recording device 1 based on control programs and data stored in the memory unit to perform processing related to the functions of the inkjet recording device 1. The paper supply unit 3, paper transport unit 4, recording unit 5, and drying unit 6 each receive commands individually from the control unit 8 and perform recording on the paper S in cooperation with each other. The memory unit is composed of a combination of a non-volatile storage device such as a program ROM (Read Only Memory) and a data ROM, and a volatile storage device such as a RAM (Random Access Memory).

[0021] Next, the configuration around the recording unit 5 will be described with reference to Fig. 3. Fig. 3 is an explanatory diagram showing the configuration of a control system and an ink supply system around the recording unit 5 of the inkjet recording apparatus 1 of Fig. 1. The inkjet recording apparatus 1 includes an ink container 10, an ink supply device (liquid supply device) 20, a sub-tank 30, and a head drive board 53.

[0022] The ink container 10 is detachably provided to the apparatus main body 2. The ink container 10 contains ink to be supplied to the subtank 30. The ink (liquid) in the ink container 10 is transported to the recording head 52 via the subtank 30.

[0023] The ink supply device 20 is disposed downstream of the ink container 10 in the ink transport direction. The ink supply device 20 includes a diaphragm pump 21, and sucks ink from the ink container 10 and ejects the ink toward the subtank 30. The operation of the diaphragm pump 21 is controlled by the control unit 8. A detailed configuration of the ink supply device 20 will be described later.

[0024] The subtank 30 stores ink to be supplied to the recording head 52. The subtank 30 is provided with an ink amount sensor (not shown). The control unit 8 controls the diaphragm pump 21 to control the amount of ink supplied from the ink container 10 to the subtank 30 depending on the driving time of the diaphragm pump 21. If the amount of ink in the subtank 30 detected by the ink amount sensor does not exceed a predetermined value even after a certain driving time of the diaphragm pump 21 has elapsed, the control unit 8 determines that the ink in the ink container 10 is empty. The amount of ink in the subtank 30 is managed so that the head difference with the recording head 52 is constant.

[0025] The head drive board 53 is disposed adjacent to the recording head 52, and transmits a drive signal to the recording head 52. The recording head 52 includes a drive element (not shown) for the ink ejection nozzle 521. The head drive board 53 transmits a drive signal having a predetermined drive waveform and drive voltage to the drive element of the ink ejection nozzle 521. The drive waveform of the drive element of the ink ejection nozzle 521 is prepared in advance according to the gradation value of the pixel (dot) of the image recorded by the ejected ink droplets. The control unit 8 controls the head drive board 53, and can change the ejection speed of the ink ejected from the recording head 52. In this way, the control unit 8 controls the operation of the recording head 52, and records an image on the paper S.

[0026] Next, the configuration of the ink supply device (liquid supply device) 20 will be outlined with reference to Fig. 4 to Fig. 8. Fig. 4, Fig. 5, Fig. 6 and Fig. 7 are a front view, a top view, a side view and a perspective view of the ink supply device 20 in Fig. 3. Fig. 8 is a vertical cross-sectional side view of the ink supply device 20 in Fig. 6.

[0027] In the following figures, arrows are appropriately drawn to indicate a radial direction Dr of the motor 211 (output shaft 211x) corresponding to the reciprocating direction of the diaphragm 213 described later. In the suction unit 22, the discharge unit 23, and the filter units (optional units) 24A and 24B, the direction away from the diaphragm 213 along the radial direction Dr (the upward direction in FIG. 8) is the ink flow direction. In detail, with respect to the suction unit 22, the discharge unit 23, and the filter units (optional units) 24A and 24B, the lower side in FIG. 8 is the upstream side of the ink flow direction, and the upper side in FIG. 8 is the downstream side of the ink flow direction.

[0028] The ink supply device 20 includes a diaphragm pump 21, a suction unit 22, a discharge unit 23, and filter units (optional units) 24A and 24B.

[0029] The diaphragm pump 21 includes a motor 211 and a diaphragm mechanism 212. The diaphragm mechanism 212 houses a diaphragm 213. The diaphragm pump 21 causes the diaphragm 213 to reciprocate by the motor 211, and the reciprocating movement of the diaphragm 213 transports ink (liquid).

[0030] The suction unit 22 is connected to the diaphragm mechanism 212 of the diaphragm pump 21 so as to be adjacent to the diaphragm 213. The suction unit 22 has an inflow chamber 222 and a suction check valve 223, which are provided in the suction housing 221. The inflow chamber 222 communicates with the inside of the diaphragm mechanism 212. Ink flows into the inflow chamber 222 from the outside via the suction check valve 223. The suction check valve 223 allows ink to flow only in the suction direction relative to the diaphragm 213, i.e., in the direction flowing from the outside into the inflow chamber 222.

[0031] The discharge unit 23 is connected to the suction unit 22. In other words, the discharge unit 23 is disposed with respect to the diaphragm mechanism 212 of the diaphragm pump 21, with the suction unit 22 and the filter units 24A and 24B separated from each other. The discharge unit 23 has an outflow chamber 232 and a discharge check valve 233 provided in a discharge housing 231. The outflow chamber 232 communicates with the inflow chamber 222 via the filter units 24A and 24B. In the outflow chamber 232, ink that has flowed in from the inflow chamber 222 flows out toward the discharge check valve 233. The discharge check valve 233 allows ink to flow only in the discharge direction relative to the diaphragm 213, i.e., in the direction flowing out from the outflow chamber 232 to the outside.

[0032] The filter units 24A and 24B are disposed between the suction unit 22 and the discharge unit 23 in the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x of the motor 211. The filter units 24A and 24B each have a filter 241A or 241B that covers the cross section of the ink flow. The filter units 24A and 24B remove foreign matter contained in the ink flowing from the suction unit 22 to the discharge unit 23 by the filters 241A or 241B.

[0033] Next, the detailed configuration of the ink supply device 20 will be described with reference to Figs. 9 to 12. Fig. 9 is a vertical cross-sectional side view of the ink supply device 20 of Fig. 8, showing a state in which the components are disassembled. Fig. 10 is a vertical cross-sectional side view of the ejection unit 23 of the ink supply device 20 of Fig. 8. Fig. 11 is a vertical cross-sectional side view of the suction unit 22 of the ink supply device 20 of Fig. 8. Fig. 12 is a vertical cross-sectional side view of the filter unit 24 of the ink supply device 20 of Fig. 8. Note that in Fig. 12, the identification symbols "A" and "B" of the filter unit 24 are omitted.

[0034] The diaphragm mechanism 212 of the diaphragm pump 21 is connected to a portion from which an output shaft 211x of the motor 211 protrudes. The diaphragm mechanism 212 includes, in addition to the diaphragm 213, an eccentric cam 214 and a connecting member 215.

[0035] The eccentric cam 214 is fixed to an output shaft 211x of the motor 211. The eccentric cam 214 is formed in a circular shape that spreads outward in the radial direction Dr when viewed from the axial direction of the output shaft 211x, for example. The eccentric cam 214 is fixed to the output shaft 211x at a position eccentric from the center in the radial direction Dr with respect to the outer periphery of the circle. The motor 211 rotates the eccentric cam 214 around the axis of the output shaft 211x.

[0036] The connecting member 215 extends outward in the radial direction Dr of the output shaft 211x toward the diaphragm 213. The connecting member 215 is connected to the eccentric cam 214 and the diaphragm 213. A hole 215h is formed at one end of the connecting member 215, through which the outer periphery of the eccentric cam 214 penetrates in the axial direction of the output shaft 211x. The hole 215h of the connecting member 215 and the outer periphery of the eccentric cam 214 are connected to be smoothly slidable. When the eccentric cam 214 is rotated by the motor 211, the connecting member 215 reciprocates along the radial direction Dr of the output shaft 211x.

[0037] Further, the diaphragm mechanism 212 has a diaphragm accommodating portion 216. The diaphragm accommodating portion 216 is located outside the connecting member 215 with respect to the radial direction Dr of the output shaft 211x. The diaphragm accommodating portion 216 is formed in a rectangular parallelepiped shape when viewed from the radial direction Dr of the output shaft 211x. The diaphragm accommodating portion 216 has an opening on one side facing the suction unit 22 and the discharge unit 23.

[0038] The diaphragm accommodating portion 216 accommodates the diaphragm 213. The diaphragm 213 is fixed inside the diaphragm accommodating portion 216. The diaphragm 213 is disposed so as to face the suction unit 22 and the discharge unit 23 through the opening of the diaphragm accommodating portion 216.

[0039] The diaphragm 213 is a sheet-like member that is elastically deformable. The diaphragm 213 is formed, for example, in a circular shape that spreads in a direction perpendicular to the radial direction Dr of the output shaft 211x. The outer periphery of the diaphragm 213 is fixed to the diaphragm accommodating portion 216. The other end of the connecting member 215, which is opposite to the one end to which the eccentric cam 214 is connected, is connected to the center of the diaphragm 213.

[0040] When the eccentric cam 214 is rotated by the motor 211, the diaphragm 213 reciprocates along the radial direction Dr of the output shaft 211x via the connecting member 215. This causes the volumes of the inlet chamber 222 of the suction unit 22 and the outlet chamber 232 of the discharge unit 23 to increase and decrease. The diaphragm pump 21 transports ink by the reciprocating movement of the diaphragm 213.

[0041] The suction unit 22 is connected to the diaphragm accommodating portion 216 so as to be adjacent to the diaphragm 213. The suction unit 22 has a suction housing 221, an inflow chamber 222, and a suction check valve 223.

[0042] Suction housing 221 is formed into a rectangular parallelepiped shape with a rectangular outer shape when viewed from the radial direction Dr of output shaft 211x of motor 211. The size and shape of the outer shape (rectangle) of suction housing 221 when viewed from the radial direction Dr is the same as the size and shape of the outer shape (rectangle) of diaphragm accommodating section 216 when viewed from the radial direction Dr. Suction housing 221 is connected to diaphragm accommodating section 216 with ink sealed inside.

[0043] The inflow chamber 222 is formed as an internal space of the suction housing 221. The inflow chamber 222 is formed in a cylindrical shape extending in the radial direction Dr of the output shaft 211x. The inflow chamber 222 is open at one end and the other end in the radial direction Dr of the output shaft 211x, and openings 222a and 222b are formed. The inflow chamber 222 communicates with the diaphragm accommodating portion 216 via the opening 222a and faces the diaphragm 213. The inflow chamber 222 also communicates with the filter unit 24A via the opening 222b. Ink flows into the inflow chamber 222 from the outside via the suction check valve 223.

[0044] Further, in the inflow chamber 222, a filter 225, an inner cylinder portion 2222, a partition wall 2223, a filter holding portion 2224, a filter opposing portion 2225, a plurality of communication holes 2226, and a plurality of protrusions 2227 are provided.

[0045] The inner cylinder portion 2222 is disposed radially inside the inflow chamber 222 and in the radial center. The inner cylinder portion 2222 is disposed in the inflow chamber 222 downstream of the position where the suction check valve 223 is disposed in the ink flow direction. The inner cylinder portion 2222 is formed in a cylindrical shape extending in the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x of the motor 211. The ink flows inside the inner cylinder portion 2222 along the radial direction Dr.

[0046] The partition wall 2223 is disposed at an upstream portion of the inner cylinder portion 2222 in the ink flow direction. The partition wall 2223 is formed in a circular flat plate shape that spreads outwardly of the inner cylinder portion 2222 in a flange shape in a direction perpendicular to the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. An inner edge portion of the partition wall 2223 is connected to an upstream portion of the outer circumferential surface of the inner cylinder portion 2222 in the ink flow direction. An outer edge portion of the partition wall 2223 is connected to the inner circumferential surface of the inflow chamber 222.

[0047] The filter holding portion 2224 is formed at the downstream end in the ink flow direction of the inner tube portion 2222. The filter holding portion 2224 is configured as an annular flat surface facing the downstream side in the ink flow direction. The outer periphery of the ink flow path of the filter 241 is attached to the filter holding portion 2224. As a result, the filter holding portion 2224 holds the outer periphery of the ink flow path of the filter 225.

[0048] The filter facing portion 2225 is located inside the inner tube portion 2222 and on the inside of the ink flow path relative to the filter holding portion 2224. The filter facing portion 2225 is located on the upstream side of the downstream end of the inner tube portion 2222 in the ink flow direction and spaced apart from the filter 225. The filter facing portion 2225 is formed in a circular plate shape that spreads along the ink flow cross section in a direction perpendicular to the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The filter facing portion 2225 faces the filter 225 in the ink flow direction.

[0049] The plurality of circulation holes 2226 are formed in the filter facing portion 2225. The plurality of circulation holes 2226 are arranged in parallel at predetermined positions in a direction perpendicular to the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The plurality of circulation holes 2226 penetrate the filter facing portion 2225 in the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. Ink flows through the plurality of circulation holes 2226. That is, for example, ink that flows into the inflow chamber 222 via the suction check valve 223 passes through the plurality of circulation holes 2226 toward the filter 225.

[0050] The multiple protrusions 2227 are formed on the filter facing portion 2225. More specifically, the multiple protrusions 2227 are formed on a surface of the filter facing portion 2225 that faces the filter 225 in the ink flow direction. The multiple protrusions 2227 are juxtaposed at predetermined positions in a direction perpendicular to the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The multiple protrusions 2227 protrude in the ink flow direction toward the filter 225 in the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The protrusion length of the protrusions 2227 is preferably a length that just contacts the filter 225, but may be shorter than the length that contacts the filter 225.

[0051] Suction check valve 223 is attached to suction housing 221. Suction check valve 223 is, for example, a ball-type check valve in which a valve body is constituted by a ball. Suction check valve 223 includes a suction portion 2231, a valve body accommodating portion 2232, a liquid guide tube 2233, a seal member 2234, a valve body 2235, and a biasing member 2236.

[0052] The suction part 2231 protrudes toward the outside of the suction housing 221. The suction part 2231 is formed in a cylindrical shape, and is connected to a liquid supply tube (not shown) for transporting ink, etc. The suction unit 22 is connected to the ink container 10 (see FIG. 3) via the liquid supply tube.

[0053] The valve body accommodating portion 2232 is continuous with the suction portion 2231 and is disposed downstream of the suction portion 2231 in the ink flow direction. The liquid guide tube 2233 is continuous with the valve body accommodating portion 2232 and is disposed downstream of the valve body accommodating portion 2232 in the ink flow direction. The valve body accommodating portion 2232 and the liquid guide tube 2233 are formed in a cylindrical shape extending in the ink flow direction. The liquid guide tube 2233 communicates with the inflow chamber 222.

[0054] The valve body accommodating portion 2232 accommodates a seal member 2234 , a valve body 2235 , and a biasing member 2236 .

[0055] The seal member 2234 is disposed adjacent to the inner circumferential wall of the valve body accommodating portion 2232, on the upstream side (suction portion 2231 side) of the valve body 2235 in the ink flow direction. The seal member 2234 is an O-ring made of an elastic body such as rubber, and its outer circumferential portion is in close contact with the inner circumferential wall of the valve body accommodating portion 2232. The outer diameter of the seal member 2234 is larger than the inner diameter of the suction portion 2231. The inner diameter of the seal member 2234 is smaller than the outer diameter of the valve body 2235.

[0056] The valve body 2235 is configured as a ball (spherical shape) and is movable in the ink flow direction within the valve body housing portion 2232. When the valve body 2235 moves upstream in the ink flow direction, it comes into contact with the inner periphery of the seal member 2234 and closes the suction portion 2231. In this way, the suction check valve 223 allows ink to flow through the diaphragm 213 only in the suction direction, preventing the backflow of ink.

[0057] The urging member 2236 is disposed downstream in the ink flow direction (on the liquid guide tube 2233 side) of the valve body 2235. The urging member 2236 is formed of, for example, a compression coil spring, and the coil axis extends along the central axis of the valve body accommodating portion 2232.

[0058] An upstream end of the urging member 2236 in the ink flow direction comes into contact with the valve body 2235 which is a ball. A downstream end of the urging member 2236 in the ink flow direction comes into contact with a wall surface at the downstream end of the valve body accommodating section 2232 in the ink flow direction which faces the valve body 2235. This causes the urging member 2236 to urge the valve body 2235 toward the upstream side in the ink flow direction in a direction in which it comes into contact with the seal member 2234. The suction check valve 223 causes the valve body 2235 to come into contact with the inner periphery of the seal member 2234 by the urging member 2236, thereby allowing ink to flow through the diaphragm 213 only in the suction direction and preventing backflow of ink.

[0059] When the diaphragm pump 21 is operated, the suction force of the valve body 2235 moves downstream in the ink flow direction against the biasing force of the biasing member 2236, and ink flows from the outside of the suction unit 22 through the suction check valve 223 into the inflow chamber 222. When the diaphragm pump 21 is stopped, the biasing force of the biasing member 2236 moves the valve body 2235 upstream in the ink flow direction and contacts the seal member 2234, preventing the backflow of ink.

[0060] The discharge unit 23 is connected to the filter unit 24B. The discharge unit 23 has the discharge housing 231, the outflow chamber 232, and the discharge check valve 233, as described above.

[0061] The ejection housing 231 is formed in a substantially rectangular parallelepiped shape with a rectangular outer shape when viewed from the radial direction Dr of the output shaft 211x of the motor 211. The size and shape of the outer shape (rectangle) of the ejection housing 231 when viewed from the radial direction Dr is the same as the size and shape of the outer shapes (rectangle) of the diaphragm containing section 216, the suction housing 221, and the filter units 24A and 24B when viewed from the radial direction Dr. The ejection housing 231 is connected to a filter case 242B (described later) of the filter unit 24B with the ink sealed therein.

[0062] The outflow chamber 232 is formed as an internal space of the discharge housing 231. The outflow chamber 232 is formed in a cylindrical shape extending in the radial direction Dr of the output shaft 211x. The outflow chamber 232 has one surface at one end of the radial direction Dr of the output shaft 211x open, and an opening 232a is formed. The outflow chamber 232 communicates with the filter unit 24B via the opening 232a. In the outflow chamber 232, ink that has flowed in from the inflow chamber 222 of the suction unit 22 flows out toward the discharge check valve 233 via the filter unit 24B.

[0063] Further, a plurality of protrusions 2327 are provided in the outflow chamber 232. The plurality of protrusions 2327 are arranged in the outflow chamber 232 upstream of the arrangement position of the discharge check valve 233 in the ink flow direction. More specifically, the plurality of protrusions 2327 are formed on an end wall facing the upstream side in the ink flow direction in the outflow chamber 232. Each of the plurality of protrusions 2327 is juxtaposed at a predetermined position in a direction perpendicular to the radial direction Dr of the output shaft 211x (the reciprocating direction of the diaphragm 213).

[0064] The multiple protrusions 2327 protrude toward the upstream side in the ink flow direction in the radial direction Dr of the output shaft 211x (the reciprocating direction of the diaphragm 213). More specifically, the multiple protrusions 2327 protrude in the ink flow direction toward the filter 241 provided in the filter unit 24 adjacent to the output shaft 211x in the radial direction Dr. The protrusion length of the protrusions 2327 is preferably a length that just contacts the filter 241, but may be shorter than the length that contacts the filter 241.

[0065] The discharge check valve 233 is attached to the discharge housing 231. The discharge housing 231 is, for example, a ball-type check valve in which the valve body is formed of a ball. The discharge check valve 233 includes a discharge portion 2331, a valve body accommodating portion 2332, a liquid guide tube 2333, a seal member 2334, a valve body 2335, and a biasing member 2336.

[0066] The ejection part 2331 protrudes toward the outside of the ejection housing 231. The ejection part 2331 is formed in a cylindrical shape, and is connected to a liquid supply tube (not shown) for transporting ink, etc. The ejection unit 23 is connected to the subtank 30 (see FIG. 3) via the liquid supply tube.

[0067] The valve body accommodating portion 2332 is continuous with the ejection portion 2331 and is disposed upstream of the ejection portion 2331 in the ink flow direction. The liquid guide tube 2333 is continuous with the valve body accommodating portion 2332 and is disposed upstream of the valve body accommodating portion 2332 in the ink flow direction. The valve body accommodating portion 2332 and the liquid guide tube 2333 are formed in a cylindrical shape extending in the ink flow direction. The liquid guide tube 2333 communicates with the outflow chamber 232.

[0068] The valve body accommodating portion 2332 accommodates a seal member 2334 , a valve body 2335 , and a biasing member 2336 .

[0069] The seal member 2334 is disposed adjacent to the inner circumferential wall of the valve body accommodating portion 2332, upstream of the valve body 2335 in the ink flow direction (on the liquid guide tube 2333 side). The seal member 2334 is an O-ring made of an elastic body such as rubber, and its outer circumferential portion is in close contact with the inner circumferential wall of the valve body accommodating portion 2332. The outer diameter of the seal member 2334 is larger than the inner diameter of the liquid guide tube 2333. The inner diameter of the seal member 2334 is smaller than the outer diameter of the valve body 2335.

[0070] The valve element 2335 is configured as a ball (spherical shape) and is movable in the ink flow direction within the valve element housing portion 2332. When the valve element 2335 moves upstream in the ink flow direction, it comes into contact with the inner periphery of the seal member 2334 and closes the liquid guide tube 2333. In this way, the discharge check valve 233 allows ink to flow through the diaphragm 213 only in the discharge direction, preventing backflow of ink.

[0071] The biasing member 2336 is disposed downstream in the ink flow direction (on the ejection portion 2331 side) of the valve body 2335. The biasing member 2336 is formed of, for example, a compression coil spring, and the coil axis extends along the central axis of the valve body accommodating portion 2332.

[0072] An upstream end of the urging member 2336 in the ink flow direction comes into contact with the valve body 2335 which is a ball. A downstream end of the urging member 2336 in the ink flow direction comes into contact with a wall surface at the downstream end of the valve body accommodating section 2332 in the ink flow direction which faces the valve body 2335. As a result, the urging member 2336 urges the valve body 2335 toward the upstream side in the ink flow direction in a direction in which it comes into contact with the seal member 2334. The discharge check valve 233 allows ink to flow relative to the diaphragm 213 only in the discharge direction and prevents backflow of ink by bringing the valve body 2335 into contact with the inner periphery of the seal member 2334 by the urging member 2336.

[0073] When the diaphragm pump 21 is operated, the suction force of the valve body 2335 moves downstream in the ink flow direction against the biasing force of the biasing member 2336, and ink flows out of the outflow chamber 232 through the discharge check valve 233 to the outside of the discharge unit 23. When the diaphragm pump 21 is stopped, the biasing force of the biasing member 2336 moves the valve body 2335 upstream in the ink flow direction and makes contact with the seal member 2334, thereby preventing the backflow of ink.

[0074] By using ball-type check valves, in which the valve body is a ball, as the suction check valve 223 and the discharge check valve 233, it is possible to prevent backflow of ink with high precision. Therefore, it is possible to improve the ink transport performance of the ink supply device 20.

[0075] Furthermore, the suction check valve 223 is detachable from the suction housing 221 of the suction unit 22. Furthermore, the discharge check valve 233 is detachable from the discharge housing 231 of the discharge unit 23. With these configurations, the configuration of the check valve can be easily changed. For example, if there is a low risk of foreign matter being mixed into the ink, an umbrella valve or a duckbill valve may be used instead of the ball-type check valve. This allows the cost of the ink supply device 20 to be reduced.

[0076] 8, the suction unit 22 and the discharge unit 23 are arranged overlapping with the diaphragm pump 21 on one side in the reciprocating direction of the diaphragm 213 (upper side in the vertical direction in FIG. 8) with the filter units 24A and 24B sandwiched therebetween. In detail, the suction unit 22 and the discharge unit 23 are arranged overlapping with the filter units 24A and 24B sandwiched therebetween so that the inflow chamber 222 and the outflow chamber 232 face the diaphragm 213 on one side in the reciprocating direction of the diaphragm 213. The suction unit 22, the discharge unit 23 and the filter units 24A and 24B are detachable from each other.

[0077] In this embodiment, the diaphragm pump 21 (diaphragm accommodating portion 216), the suction unit 22, the filter units 24A and 24B, and the discharge unit 23 are connected in this order, but the suction unit 22 and the discharge unit 23 may be interchanged. In this case, the external shapes of the suction housing 221 and the discharge housing 231 are changed so that the diaphragm pump 21 (diaphragm accommodating portion 216), the discharge unit 23, and the suction unit 22 can be connected in this order. Alternatively, the suction check valve 223 and the discharge check valve 233 may be interchanged.

[0078] Furthermore, it is sufficient that at least one of the optional filter units 24A and 24B is provided.

[0079] According to the above configuration, the option units (filter units 24A, 24B) are disposed upstream in the ink flow direction of the ejection unit 23 on the ink ejection side relative to the diaphragm 213. The option units can be configured to perform various treatments on the circulating ink. Therefore, it is possible to prevent deterioration of the ink ejected from the diaphragm pump 21 or to improve the quality of the ink.

[0080] The optional units are filter units 24A and 24B having filters 241A and 241B that cover the cross section of the ink flow. With this configuration, foreign matter contained in the ink that has flowed into the suction unit 22 can be removed by the filters 241A and 241B. This prevents the ink discharged from the discharge unit 23, i.e., the ink supply device 20, from containing foreign matter, making it possible to suppress damage to the recording head 52 and the like and deterioration of image quality.

[0081] In addition, one of the suction unit 22, which is an ink suction portion for the diaphragm 213, and the discharge unit 23, which is a discharge portion, is disposed adjacent to the diaphragm 213 so as to face the diaphragm 213, and the other is disposed overlapping the one. Either the suction unit 22 or the discharge unit 23 can be disposed adjacent to the diaphragm 213. In other words, the respective positions of the ink suction portion and the discharge portion for the diaphragm pump 21 can be changed as desired, improving the degree of freedom in the configuration of the ink flow path. As a result, the ink supply device 20 can efficiently transport ink in response to the various configurations of the inkjet recording device 1 in which it is installed.

[0082] The filter unit 24A has a filter 241 A and a filter case 242 A. The filter unit 24B has a filter 241 B and a filter case 242 B. The filter unit 24A is disposed upstream of the filter unit 24B in the ink flow direction.

[0083] Filter units 24A and 24B have the same basic configuration, except for the mesh size of filters 241A and 241B. Therefore, in the following description, the identification symbols "A" and "B" may be omitted unless otherwise specified.

[0084] The filter 241 is a sheet-like member that extends in a direction perpendicular to the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x of the motor 211 and parallel to the diaphragm 213. The filter 241 is made of, for example, a metal mesh filter. The filter 241 is held by a filter case 242 and covers the cross section through which ink flows.

[0085] The filters 241A and 241B have different mesh sizes (openings, aperture ratio). For example, the filter 241B has finer mesh (smaller openings, aperture ratio) than the filter 241A located upstream in the ink flow direction. That is, the two filter units 24A and 24B have finer meshes from the suction unit 22 side to the discharge unit 23 side.

[0086] According to the above configuration, foreign matter of different sizes contained in the ink can be removed in sequence by the two filter units 24A and 24B. In this way, by adjusting the mesh size of the filters 241A and 241B, foreign matter contained in the ink can be removed more effectively. It is also possible to prevent clogging of the filters 241A and 241B.

[0087] More specifically, the filter 241A has finer mesh (smaller mesh opening rate) than the filter 225 of the suction unit 22 located upstream in the ink flow direction. That is, the mesh of the three filters 225, 241A, 241B becomes finer from the suction unit 22 side toward the discharge unit 23 side.

[0088] According to the above configuration, foreign matter of different sizes contained in the ink can be removed in order by the three filters 225, 241A, and 241B. By adjusting the mesh size of the filters 225, 241A, and 241B in this way, foreign matter contained in the ink can be removed more effectively. It is also possible to prevent clogging of the filters 225, 241A, and 241B.

[0089] Furthermore, the detailed configuration of filter unit 24 will be described with reference to Fig. 13 and Fig. 14 in addition to Fig. 12. Fig. 13 is a top view of filter unit 24 in Fig. 12. Fig. 14 is a top view of filter unit 24 in Fig. 12, showing a state in which filter 241 has been removed. Note that in Figs. 13 and 14, the identification symbols "A" and "B" of filter unit 24 have been omitted.

[0090] The filter case 242 of the filter unit 24 has an outer cylinder portion 2421 , an inner cylinder portion 2422 , a flat plate portion 2423 , a filter holding portion 2424 , a filter opposing portion 2425 , a plurality of communication holes 2426 , and a plurality of protrusions 2427 .

[0091] The outer cylinder portion 2421 is disposed in the center of the filter case 242. The inner cylinder portion 2422 is disposed radially inside the outer cylinder portion 2421. The outer cylinder portion 2421 and the inner cylinder portion 2422 are formed in a cylindrical shape extending in the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x of the motor 211. With respect to the ink flow direction in the filter unit 24, the inner cylinder portion 2422 is disposed in the upstream portion, and the outer cylinder portion 2421 is disposed in the downstream portion. The insides of the outer cylinder portion 2421 and the inner cylinder portion 2422 communicate with each other at approximately the center portion in the ink flow direction. The downstream portion of the inner cylinder portion 2422 in the ink flow direction protrudes downstream in the outer cylinder portion 2421. Ink flows in the inner cylinder portion 2422 and the outer cylinder portion 2421 in this order along the radial direction Dr.

[0092] The flat plate portion 2423 spreads outwardly of the outer cylinder portion 2421 in a flange shape in a direction perpendicular to the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The outer shape of the flat plate portion 2423 is rectangular when viewed from the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The size and shape of the outer shape (rectangle) of the flat plate portion 2423 when viewed from the radial direction Dr is the same as the size and shape of the outer shape (rectangle) of the suction housing 221 and the discharge housing 231 when viewed from the radial direction Dr. The flat plate portion 2423 faces and comes into contact with the flat plate portions 2423 of the other filter units 24, the suction housing 221, and the discharge housing 231 in the ink flow direction.

[0093] The filter holding portion 2424 is formed at the downstream end of the inner tube portion 2422 that protrudes downstream in the ink flow direction inside the outer tube portion 2421. The filter holding portion 2424 is configured as an annular flat surface facing downstream in the ink flow direction. The outer periphery of the ink flow path of the filter 241 is attached to the filter holding portion 2424. As a result, the filter holding portion 2424 holds the outer periphery of the ink flow path of the filter 241.

[0094] The filter facing portion 2425 is located inside the inner tube portion 2422 and on the inside of the ink flow path relative to the filter holding portion 2424. The filter facing portion 2425 is located upstream of the downstream end of the inner tube portion 2422 in the ink flow direction and spaced apart from the filter 241. The filter facing portion 2425 is formed in a circular plate shape that spreads along the ink flow cross section in a direction perpendicular to the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The filter facing portion 2425 faces the filter 241 in the ink flow direction.

[0095] The plurality of circulation holes 2426 are formed in the filter facing portion 2425. The plurality of circulation holes 2426 are arranged in parallel at predetermined positions in a direction perpendicular to the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The plurality of circulation holes 2426 penetrate the filter facing portion 2425 in the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. Ink flows through the plurality of circulation holes 2426. That is, for example, ink that has reached the filter unit 24 from the inflow chamber 222 of the suction unit 22 passes through the plurality of circulation holes 2426 toward the filter 241.

[0096] The multiple protrusions 2427 are formed on the filter facing portion 2425. Specifically, the multiple protrusions 2427 are formed on each of a surface of the filter facing portion 2425 that faces the filter 241 in the ink flow direction and a surface on the opposite side thereof. The multiple protrusions 2427 are juxtaposed at predetermined positions in a direction perpendicular to the radial direction Dr of the output shaft 211x (the reciprocating direction of the diaphragm 213).

[0097] The multiple protrusions 2427 protrude in the ink flow direction toward the filter 241 in the radial direction Dr of the output shaft 211x (the reciprocating direction of the diaphragm 213). In detail, the multiple protrusions 2427 formed on the surface of the filter facing part 2425 facing the filter 241 protrude toward the filter 241. On the other hand, the multiple protrusions 2427 formed on a surface of the filter facing part 2425 opposite to the surface facing the filter 241 protrude toward the filter 241 provided in another filter unit 24 adjacent in the radial direction Dr of the output shaft 211x, or the filter 225 provided in the suction unit 22. The protrusion length of the protrusion 2427 is preferably a length that just contacts the filters 241 and 225, but may be shorter than the length that contacts the filters 241 and 225.

[0098] According to the above configuration, the filter 241, which tends to be displaced in the ink flow direction due to pressure during ink flow, can be supported by the multiple protrusions 2427. This makes it possible to suppress displacement and deformation of the filter 241. Therefore, it becomes possible to achieve favorable ink transport performance.

[0099] In addition, each of the multiple protrusions 2427 formed on one side of the filter facing portion 2425 and each of the multiple protrusions 2427 formed on the other side are arranged at the same position in a direction perpendicular to the radial direction Dr (reciprocating direction of the diaphragm 213) of the output shaft 211x with respect to the ink flow direction. In addition, each of the multiple protrusions 2227 formed on the suction unit 22 and each of the multiple protrusions 2327 formed on the discharge unit 23 are also arranged at the same position as each of the multiple protrusions 2427 formed on the filter unit 24 in a direction perpendicular to the radial direction Dr (reciprocating direction of the diaphragm 213) of the output shaft 211x. That is, each of the multiple protrusions 2427, 2227, 2327 has a protruding tip portion facing each other in the ink flow direction.

[0100] According to the above configuration, the filters 241 and 225 can be sandwiched in the ink flow direction between the tips of the multiple protrusions 2427, 2227, and 2327. This enhances the effect of suppressing displacement and deformation of the filters 241 and 225. Therefore, it becomes possible to maintain favorable ink transport performance.

[0101] Next, modified examples of the ink supply device 20 will be described. Fig. 15 is a top view of an optional unit (heater unit 24C) of modified example 1. Fig. 16 is a top view of an optional unit (heater unit 24D) of modified example 2. Note that the basic configuration of the modified examples is the same as that of the embodiment previously described using Figs. 1 to 14, and therefore common components may be given the same reference numerals or names as before and their description may be omitted.

[0102] The ink supply device 20 may be provided with heater units 24C and 24D shown in FIG. 15 or FIG. 16 as optional units.

[0103] 15, the heater unit 24C has a heating section 246, for example, inside an inner cylinder section 2422. The heating section 246 is configured by a coil that is installed in the inner cylinder section 2422 in a direction perpendicular to the radial direction Dr of the output shaft 211x of the motor 211. The ink passing through the inner cylinder section 2422 of the heater unit 24C is heated by the heating section 246.

[0104] 16, the heater unit 24D has a heating part 247, for example, inside the inner cylinder part 2422. The heating part 247 is configured by a ceramic heater attached to the filter facing part 2425 inside the inner cylinder part 2422. The ink passing through the inner cylinder part 2422 of the heater unit 24C is heated by the heating part 247.

[0105] As described above, the optional units may be heater units 24C, 24D having heating sections 246, 247 for heating ink. With this configuration, the ink that has flowed into the suction unit 22 can be heated by the heating sections 246, 247. This allows proper temperature management of the ink discharged from the discharge unit 23, i.e., the ink supply device 20, and makes it possible to improve image quality.

[0106] 8 and 9, the ink supply device 20 includes three outer seal members 25A, 25B, and 25C. The three outer seal members 25A, 25B, and 25C are O-rings made of an elastic body such as rubber.

[0107] The outer seal member 25A is disposed between the suction unit 22 and the filter unit 24A. Specifically, the outer seal member 25A is disposed between the inner edge of the opening 222b of the suction unit 22 and the outer edge of the upstream part in the ink flow direction of the inner cylinder portion 2422 of the filter unit 24A.

[0108] The outer seal member 25B is disposed between the filter unit 24A and the filter unit 24B. Specifically, the outer seal member 25B is disposed between an inner edge portion of a downstream portion in the ink flow direction of an outer cylinder portion 2421 of the filter unit 24A and an outer edge portion of an upstream portion in the ink flow direction of an inner cylinder portion 2422 of the filter unit 24B.

[0109] The outer seal member 25C is disposed between the filter unit 24B and the discharge unit 23. In detail, the outer seal member 25C is disposed between an inner edge portion of a downstream portion in the ink flow direction of the outer cylinder portion 2421 of the filter unit 24B and an outer edge portion of the opening 232a of the discharge unit 23.

[0110] The three outer seal members 25A, 25B, and 25C are disposed between the suction unit 22, the discharge unit 23, and the filter units 24A and 24B, respectively, to prevent ink from leaking to the outside. With this configuration, it is possible to suppress a decrease in ink transport performance, and further to prevent ink contamination inside the inkjet recording apparatus 1.

[0111] 6, 7, and 10, the discharge unit 23 has a plurality of unit positioning shafts 234. The unit positioning shafts 234 are disposed at the four corners of the discharge housing 231 that is rectangular when viewed from the radial direction Dr of the output shaft 211x of the motor 211 (see FIG. 7). That is, the discharge unit 23 has four unit positioning shafts 234.

[0112] The four unit positioning shafts 234 extend toward the filter unit 24, the suction unit 22, and the diaphragm pump 21. In other words, the four unit positioning shafts 234 extend along the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. A male screw is formed on the outer periphery of the tip of the unit positioning shaft 234.

[0113] 12 and 13, the filter unit 24 has a plurality of unit positioning holes 245. The plurality of unit positioning holes 245 are arranged at four corners of the filter unit 24, which is rectangular when viewed from the radial direction Dr of the output shaft 211x of the motor 211. That is, the filter unit 24 has four unit positioning holes 245.

[0114] The four unit positioning holes 245 extend toward the discharge unit 23, the suction unit 22, and the diaphragm pump 21. In other words, the four unit positioning holes 245 extend along the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x, and penetrate the filter unit 24. In detail, the four unit positioning holes 245 penetrate the flat plate portion 2423 of the filter case 242. The unit positioning holes 245 do not communicate with the inside of the outer cylinder portion 2421 and the inside of the inner cylinder portion 2422. The four unit positioning shafts 234 are individually inserted into each of the four unit positioning holes 245.

[0115] 6 and 11, the suction unit 22 has a plurality of unit positioning holes 224. The unit positioning holes 224 are arranged at the four corners of the suction housing 221 that is rectangular when viewed from the radial direction Dr of the output shaft 211x of the motor 211. That is, the suction unit 22 has four unit positioning holes 224.

[0116] The four unit positioning holes 224 extend toward the filter unit 24, the discharge unit 23, and the diaphragm pump 21. In other words, the four unit positioning holes 224 extend along the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x, and penetrate the suction housing 221. The unit positioning holes 224 do not communicate with the inflow chamber 222. Four unit positioning shafts 234 are individually inserted into the four unit positioning holes 224, respectively.

[0117] 6, the diaphragm accommodating portion 216 has a plurality of unit positioning holes 2161. The unit positioning holes 2161 are arranged at the four corners of the diaphragm accommodating portion 216 which is rectangular when viewed from the radial direction Dr of the output shaft 211x of the motor 211. That is, the diaphragm accommodating portion 216 has four unit positioning holes 2161.

[0118] The four unit positioning holes 2161 extend toward the suction unit 22, the filter unit 24, and the discharge unit 23. In other words, the four unit positioning holes 2161 extend along the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x, and penetrate the diaphragm accommodating portion 216. Note that the unit positioning holes 2161 do not communicate with the ink flow region in the diaphragm accommodating portion 216. The four unit positioning shafts 234 are individually inserted into the four unit positioning holes 2161, respectively.

[0119] The tips of the four unit positioning shafts 234 protrude outward from one surface (the lower side in FIG. 6 ) opposite the diaphragm accommodating portion 216 with respect to the suction unit 22, the filter unit 24, and the discharge unit 23. The four unit positioning shafts 234 are inserted into four nuts 26 arranged on the opposite side of the diaphragm accommodating portion 216 with respect to the suction unit 22, the filter unit 24, and the discharge unit 23, and fasten the suction unit 22, the filter unit 24, the discharge unit 23, and the diaphragm accommodating portion 216 together.

[0120] According to the above configuration, it is possible to properly position the suction unit 22, the filter unit (optional unit) 24, and the discharge unit 23 with respect to the diaphragm pump 21 (diaphragm containing portion 216). It is also possible to prevent ink from leaking from the connection portions between the suction unit 22, the filter unit (optional unit) 24, the discharge unit 23, and the diaphragm containing portion 216.

[0121] 6 and 7, a plate-shaped member 27 is disposed on one surface of the suction unit 22, the filter unit 24, and the discharge unit 23 on the opposite side of the diaphragm accommodating portion 216 (the lower side in FIG. 6). The plate-shaped member 27 is disposed between the diaphragm accommodating portion 216 and the four nuts 26. FIG. 17 is a perspective view of the plate-shaped member 27 of the ink supply device 20 in FIG. 6.

[0122] The plate-like member 27 is formed in a C-shape when viewed from a radial direction Dr (reciprocating direction of the diaphragm 213) of the output shaft 211x of the motor 211. The outer shape of the plate-like member 27 is substantially rectangular when viewed from the radial direction Dr of the output shaft 211x, and is substantially the same as the size and shape of the outer shape (rectangle) of the diaphragm accommodating portion 216 when viewed from the radial direction Dr. The plate-like member 27 is attached so as to fit along the diaphragm accommodating portion 216 by inserting an open part of the C-shape in a plan view into the diaphragm mechanism portion 212.

[0123] The plate-shaped member 27 has a plurality of plate-shaped member positioning holes 271. The plate-shaped member positioning holes 271 are arranged at the four corners of the plate-shaped member 27, which has a substantially rectangular outer shape when viewed from the radial direction Dr of the output shaft 211x. That is, the plate-shaped member 27 has four plate-shaped member positioning holes 271. The four plate-shaped member positioning holes 271 penetrate the plate-shaped member 27 in the radial direction Dr of the output shaft 211x (the reciprocating direction of the diaphragm 213). The four unit positioning shafts 234 are individually inserted into each of the four plate-shaped member positioning holes 271.

[0124] By providing the plate-like member 27 adjacent to the diaphragm housing portion 216, it is possible to increase the fastening strength of the suction unit 22, the filter unit 24, the discharge unit 23, and the diaphragm housing portion 216 by the unit positioning shaft 234. Therefore, it is possible to effectively suppress leakage of ink from the connection portions between the suction unit 22, the filter unit 24, the discharge unit 23, and the diaphragm housing portion 216.

[0125] Although an embodiment of the present invention has been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention.

[0126] For example, in the above embodiment, the ink supply device 20 is provided with two filter units 24A and 24B as optional units, but is not limited to this configuration. The number of optional units may be three or more. For example, the ink supply device 20 may further include one of the heater units 24C and 24D in addition to the two filter units 24A and 24B. [Industrial Applicability]

[0127] The present invention can be used in a liquid supplying apparatus and an inkjet recording apparatus. [Explanation of symbols]

[0128] 1 Inkjet recording device 5 Recording section 10 Ink Container 20 Ink supply device (liquid supply device) 21 Diaphragm Pump 22 Inhalation unit 23 Discharge unit 24A, 24B Filter Unit (Optional Unit) 24C, 24D heater unit (optional unit) 25A, 25B, 25C Outer seal material 26 Nut 27 Plate-shaped members 30 Subtank 52 Recording head 211 Motor 211x output shaft 212 Diaphragm mechanism 213 Diaphragm 216 Diaphragm housing 221 Intake housing 222 Inflow chamber 223 Intake check valve 224 Unit positioning hole 225 Filter 231 Discharge housing 232 Outflow chamber 233 Discharge check valve 234 Unit positioning shaft 241A, 241B Filters 245 Unit positioning hole 246, 247 Heating section 271 Plate-shaped member positioning hole 2161 Unit positioning hole 2222 Inner cylinder 2223 Bulkhead 2224 Filter holder 2225 Filter opposing part 2226 Flow hole 2227 Protrusion 2327 Protrusion 2421 Outer cylinder 2422 Inner cylinder 2423 Flat plate part 2424 Filter holder 2425 Filter opposing part 2426 Flow hole 2427 Protrusion Dr radial direction

Claims

1. a diaphragm pump that transports liquid by reciprocating movement of a diaphragm; a suction unit including an intake check valve that allows the liquid to flow through the diaphragm only in a suction direction, and an inflow chamber into which the liquid flows via the intake check valve; a discharge unit including a discharge check valve that allows the liquid to flow only in a discharge direction relative to the diaphragm, and an outflow chamber through which the liquid that has flowed in from the inflow chamber flows out toward the discharge check valve; an optional unit disposed between the suction unit and the discharge unit; Equipped with the suction unit and the discharge unit are arranged in a stacked manner with at least one optional unit sandwiched therebetween, such that the inflow chamber and the outflow chamber face the diaphragm continuously on one side of the reciprocating direction of the diaphragm, The liquid supplying device, wherein the suction unit, the discharge unit, and the option unit are detachable from one another.

2. 2. The liquid supply device according to claim 1, wherein the optional unit is a filter unit having a filter that covers a cross section of the liquid flow.

3. A plurality of filter units having filters with different mesh sizes are disposed between the suction unit and the discharge unit, 3. The liquid supplying device according to claim 2, wherein the mesh of the filters of the plurality of filter units becomes finer from the suction unit side to the discharge unit side.

4. The filter unit comprises: The filter; A filter retaining part that retains an outer periphery of a liquid flow path of the filter; a filter facing portion that is located inside the liquid flow path relative to the upstream holding portion and faces the filter in the liquid flow direction while being spaced apart from the filter in the liquid flow direction; A plurality of flow holes formed in the filter facing portion through which the liquid flows; A plurality of protrusions formed on the filter facing portion and protruding toward the filter; The liquid supply device according to claim 2, further comprising:

5. 2. The liquid supply device according to claim 1, wherein the optional unit is a heater unit having a heating portion for heating the liquid.

6. one of the suction unit and the discharge unit has a plurality of unit positioning shafts that are inserted into a plurality of unit positioning holes that the other of the suction unit and the discharge unit and the optional unit have; The diaphragm pump has a diaphragm accommodating portion that accommodates the diaphragm, a plate-like member disposed on an opposite side of the diaphragm accommodating portion with respect to the suction unit, the discharge unit, and the optional unit, the plate-like member being formed in a C-shape as viewed from a reciprocating direction of the diaphragm; 2. The liquid supply apparatus according to claim 1, wherein the plate-like member has a plurality of plate-like member positioning holes into which a plurality of the unit positioning shafts are inserted.

7. 2. The liquid supply device according to claim 1, wherein the discharge check valve is a ball-type check valve having a valve body made of a ball.

8. 2. The liquid supply device according to claim 1, wherein the suction check valve is detachable from a housing of the suction unit.

9. 2. The liquid supplying apparatus according to claim 1, wherein the discharge check valve is detachable from a housing of the discharge unit.

10. a recording head that ejects ink to record an image; A liquid supplying device according to any one of claims 1 to 9, which supplies ink to the recording head; An inkjet recording apparatus comprising:

Images