Liquid feeding device and inkjet recording apparatus

Abstract

To provide a liquid feeding device which prevents foreign objects from getting caught in a valve at the liquid discharge side in a diaphragm pump to improve ink conveyance performance.SOLUTION: A liquid feeding device 20 includes a diaphragm pump 21, a suction unit 22, a discharge unit 23, and a filter unit 24. The filter unit 24 is disposed between the suction unit 22 and the discharge unit 23 and includes a filter 241 covering a flow cross section of an ink. 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 the ink face a diaphragm 213 on one side in a reciprocating direction of the diaphragm 213 with the filter unit 24 sandwiched therebetween.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 possibility of foreign matter getting caught in the outlet valve of the outlet. In the conventional technology, there was a concern that the performance of the pump in terms of transporting liquid would be significantly reduced if foreign matter got caught in the outlet valve of the outlet.

[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 are capable of suppressing foreign matter from getting caught in the valve on the liquid ejection side of the diaphragm pump and improving the liquid transport performance. [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 a filter unit. The diaphragm pump transports liquid by reciprocating movement of a diaphragm. The suction unit includes 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 includes a discharge check valve that allows the liquid to flow only in the discharge direction relative to the diaphragm, and an outflow chamber into which the liquid that flows in from the inflow chamber flows out toward the discharge check valve. The filter unit is disposed between the suction unit and the discharge unit, and includes a filter that covers a cross section of the liquid flow. The suction unit and the discharge unit are disposed overlapping each other with the filter unit sandwiched therebetween, such that the inflow chamber and the outflow chamber face the diaphragm on one side of the reciprocating direction of the diaphragm. The filter unit includes the filter, an upstream case, a downstream case, and an inner seal member. The upstream case and the downstream case sandwich the filter from the upstream side and the downstream side in a liquid flow direction through the filter. The inner seal member is disposed between the upstream case and the downstream case and prevents the liquid from leaking from the filter unit to the outside. Effect of the Invention

[0008] According to the configuration of the present invention, the filter unit is disposed upstream in the liquid flow direction of the discharge unit on the liquid discharge side relative to the diaphragm. This allows the filter unit to remove foreign matter contained in the liquid that has flowed into the suction unit. This makes it possible to prevent foreign matter from getting caught in the discharge check valve of the discharge unit, thereby improving the liquid transport performance. [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 bottom view of the filter unit of FIG. 12. [Figure 15]13 is a perspective view of the filter unit of FIG. 12 as viewed from the upstream side in the ink flow direction. FIG. [Figure 16] 13 is a bottom view of the downstream case of the filter unit of FIG. 12. [Figure 17] 13 is a perspective view of a downstream case of the filter unit in FIG. 12 as viewed from the upstream side in the ink flow direction. [Figure 18] 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 unit 24, the direction away from the diaphragm 213 (upward in FIG. 8) along the radial direction Dr is the ink flow direction. In detail, with respect to the suction unit 22, the discharge unit 23, and the filter unit 24, 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 a filter unit 24.

[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 unit 24 interposed between them. 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 unit 24. 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 in which ink flows out from the outflow chamber 232 to the outside.

[0032] The filter unit 24 is 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 unit 24 has a filter 241 that covers the ink flow cross section. The filter unit 24 removes foreign matter contained in the ink flowing from the suction unit 22 to the discharge unit 23 by the filter 241.

[0033] Next, a 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.

[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 the suction housing 221, the inflow chamber 222, and the suction check valve 223, as described above.

[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 24 via the opening 222b. Ink flows into the inflow chamber 222 from the outside via a suction check valve 223.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] The valve body accommodating portion 2232 accommodates a seal member 2234 , a valve body 2235 , and a biasing member 2236 .

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] The discharge unit 23 is connected to the filter unit 24. The discharge unit 23 has the discharge housing 231, the outflow chamber 232, and the discharge check valve 233, as described above.

[0054] 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 are the same as the size and shape of the outer shapes (rectangle) of the diaphragm containing portion 216, the suction housing 221, and the filter unit 24 when viewed from the radial direction Dr. The ejection housing 231 is connected to a downstream case 243 (described later) of the filter unit 24 with the ink sealed therein.

[0055] 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. One face of the outflow chamber 232 at one end of the radial direction Dr of the output shaft 211x is open, and an opening 232a is formed. The outflow chamber 232 communicates with the filter unit 24 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 24.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] The valve body accommodating portion 2332 accommodates a seal member 2334 , a valve body 2335 , and a biasing member 2336 .

[0060] 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 material 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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 unit 24 sandwiched therebetween. In detail, the suction unit 22 and the discharge unit 23 are arranged overlapping with the filter unit 24 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 unit 24 are detachable from one another.

[0068] In this embodiment, the diaphragm pump 21 (diaphragm accommodating portion 216), the suction unit 22, the filter unit 24, 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.

[0069] According to the above configuration, 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.

[0070] The filter unit 24 includes a filter 241 , an upstream case 242 , a downstream case 243 , and an inner seal member 244 .

[0071] 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 disposed between the upstream case 242 and the downstream case 243, and covers the cross section through which the ink flows.

[0072] The upstream case 242 is disposed on the upstream side (suction unit 22 side) of the ink flow direction relative to the filter 241. The downstream case 243 is disposed on the downstream side (ejection unit 23 side) of the ink flow direction relative to the filter 241. The upstream case 242 and the downstream case 243 are formed in a substantially rectangular parallelepiped shape with a rectangular outer shape when viewed from the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x of the motor 211. The size and shape of the outer shape (rectangle) of the upstream case 242 and the downstream case 243 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 ejection housing 231 when viewed from the radial direction Dr.

[0073] The upstream case 242 and the downstream case 243 sandwich the filter 241 therebetween in the ink flow direction, and hold the filter 241 .

[0074] The inner seal member 244 is disposed between the upstream case 242 and the downstream case 243. More specifically, the inner seal member 244 is disposed adjacent to the outer periphery of the cylindrical portion 2421 of the upstream case 242. The inner seal member 244 is an O-ring made of an elastic body such as rubber, and an inner periphery thereof is in close contact with the outer periphery wall of the cylindrical portion 2421 of the upstream case 242. The outer periphery of the inner seal member 244 which is an O-ring is in close contact with the downstream case 243. The inner seal member 244 prevents ink from leaking from the filter unit 24 to the outside.

[0075] According to the above configuration, the filter unit 24 is disposed upstream in the ink flow direction of the ejection unit 23 on the ink ejection side relative to the diaphragm 213. This allows the filter unit 24 to remove foreign matter contained in the ink that has flowed into the suction unit 22. This makes it possible to prevent foreign matter from getting caught in the ejection check valve 233 of the ejection unit 23, thereby improving the ink transport performance. In addition, it is possible to prevent the ink ejected from the ejection unit 23, i.e., the ink supply device 20, from containing foreign matter, thereby making it possible to prevent damage to the recording head 52, etc., and deterioration of image quality.

[0076] Further, the detailed configuration of the filter unit 24 will be described with reference to Fig. 12 as well as Fig. 13 to Fig. 17. Figs. 13, 14 and 15 are a top view, a bottom view and a perspective view of the filter unit 24 in Fig. 12 as viewed from the upstream side in the ink flow direction. Figs. 16 and 17 are a bottom view and a perspective view of the downstream case 243 of the filter unit 24 in Fig. 12 as viewed from the upstream side in the ink flow direction.

[0077] The upstream case 242 of the filter unit 24 has a cylindrical portion 2421 , a flat plate portion 2422 , an upstream holding portion 2423 , an upstream opposing portion 2424 , a plurality of upstream communication holes 2425 , and a plurality of upstream protrusions 2426 .

[0078] The cylindrical portion 2421 is disposed in the center of the upstream case 242. The cylindrical portion 2421 extends in a radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x of the motor 211. Ink flows inside the cylindrical portion 2421 along the radial direction Dr.

[0079] The flat plate portion 2422 spreads outwardly of the cylindrical 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 2422 is rectangular when viewed from the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The flat plate portion 2422 faces and contacts the flat plate portion 2432 of the downstream case 243 in the ink flow direction.

[0080] The upstream holding portion 2423 is formed at the downstream end in the ink flow direction of the outer periphery of the cylindrical portion 2421. The upstream holding portion 2423 is configured as an annular flat surface facing the downstream case 243. The upstream holding portion 2423 contacts the downstream case 243 across the outer periphery of the ink flow path of the filter 241.

[0081] The upstream facing portion 2424 is located on the inner side of the ink flow path of the cylindrical portion 2421 relative to the upstream holding portion 2423. The upstream facing portion 2424 is located upstream of the ink flow direction and spaced apart from the filter 241 relative to the downstream end of the cylindrical portion 2421 in the ink flow direction. The upstream facing portion 2424 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 upstream facing portion 2424 faces the filter 241 in the ink flow direction.

[0082] The upstream side circulation holes 2425 are formed in the upstream facing portion 2424. The upstream side circulation holes 2425 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 upstream side circulation holes 2425 penetrate the upstream facing portion 2424 in the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. Ink flows through the upstream side circulation holes 2425. That is, the ink that has reached the filter unit 24 from the inflow chamber 222 of the suction unit 22 passes through the upstream side circulation holes 2425 and heads toward the filter 241.

[0083] The upstream protrusions 2426 are formed on the upstream facing portion 2424. More specifically, the upstream protrusions 2426 are formed on a surface of the upstream facing portion 2424 facing the filter 241 on the downstream side in the ink flow direction. The upstream protrusions 2426 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 upstream protrusions 2426 protrude toward the downstream side in the ink flow direction toward the filter 241 in the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The protrusion length of the upstream protrusions 2426 is preferably a length that just contacts the filter 241, but may be shorter than the length that contacts the filter 241.

[0084] 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 upstream protrusions 2426. This makes it possible to suppress displacement and deformation of the filter 241. Therefore, it is possible to achieve favorable ink transport performance.

[0085] The downstream case 243 of the filter unit 24 has a cylindrical portion 2431 , a flat plate portion 2432 , a downstream holding portion 2433 , a downstream opposing portion 2434 , a plurality of downstream communication holes 2435 , and a plurality of downstream protrusions 2436 .

[0086] The cylindrical portion 2431 is disposed in the center of the downstream case 243. The cylindrical portion 2431 extends in a radial direction Dr (a reciprocating direction of the diaphragm 213) of the output shaft 211x of the motor 211. The cylindrical portion 2431 also includes a downstream portion in the ink flow direction of the cylindrical portion 2421 of the upstream case 242. The ink flows inside the cylindrical portion 2431 along the radial direction Dr.

[0087] The flat plate portion 2432 spreads outwardly of the cylindrical portion 2431 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 2432 is rectangular when viewed from the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The flat plate portion 2432 faces and contacts the flat plate portion 2422 of the upstream case 242 in the ink flow direction.

[0088] The downstream holding portion 2433 is formed on the downstream portion in the ink flow direction of the inner periphery of the cylindrical portion 2431. The downstream holding portion 2433 is configured as an annular flat surface facing the cylindrical portion 2421 of the upstream case 242 contained in the cylindrical portion 2431. The downstream holding portion 2433 contacts the upstream case 242 across the outer periphery of the ink flow path of the filter 241.

[0089] The downstream facing portion 2434 is located on the inner side of the ink flow path of the cylindrical portion 2431 relative to the downstream holding portion 2433. The downstream facing portion 2434 is located downstream in the ink flow direction relative to the downstream end of the cylindrical portion 2431 in the ink flow direction and spaced apart from the filter 241. The downstream facing portion 2434 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 downstream facing portion 2434 faces the filter 241 in the ink flow direction.

[0090] The downstream side circulation holes 2435 are formed in the downstream side facing portion 2434. The downstream side circulation holes 2435 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 downstream side circulation holes 2435 penetrate the downstream side facing portion 2434 in the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. Ink flows through the downstream side circulation holes 2435. That is, the ink that has passed through the filter 241 in the filter unit 24 passes through the downstream side circulation holes 2435 and heads toward the outflow chamber 232 of the discharge unit 23.

[0091] The downstream protrusions 2436 are formed on the downstream facing portion 2434. More specifically, the downstream protrusions 2436 are formed on a surface of the downstream facing portion 2434 facing the filter 241 on the upstream side in the ink flow direction. The downstream protrusions 2436 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 downstream protrusions 2436 protrude toward the upstream side in the ink flow direction toward the filter 241 in the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. The protrusion length of the downstream protrusions 2436 is preferably a length that just contacts the filter 241, but may be shorter than the length that contacts the filter 241.

[0092] 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 downstream protrusions 2436. This makes it possible to suppress displacement and deformation of the filter 241. Therefore, it becomes possible to achieve favorable ink transport performance.

[0093] Further, each of the multiple upstream protrusions 2426 and each of the multiple downstream protrusions 2436 are disposed at the same position in a direction perpendicular to the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. That is, each of the multiple upstream protrusions 2426 and each of the multiple downstream protrusions 2436 have their protruding tips facing each other in the ink flow direction.

[0094] According to the above configuration, the filter 241 can be sandwiched in the ink flow direction between the respective tips of the multiple upstream protrusions 2426 and the multiple downstream protrusions 2436. This enhances the effect of suppressing the displacement and deformation of the filter 241. Therefore, it becomes possible to maintain favorable ink transport performance.

[0095] The downstream case 243 also has an annular rib portion 2437. The annular rib portion 2437 is formed on a surface of the flat plate portion 2432 that faces the flat plate portion 2422 of the upstream case 242. The annular rib portion 2437 is disposed radially outward from a circular edge portion at the upstream end, in the ink flow direction, of the cylindrical portion 2431. The annular rib portion 2437 protrudes upstream in the ink flow direction toward the flat plate portion 2422 of the upstream case 242.

[0096] The upstream case 242 has an annular recess 2427 that houses the annular rib portion 2437. The annular recess 2427 is formed on a surface of the flat plate portion 2422 that faces the flat plate portion 2432 of the downstream case 243. The annular recess 2427 is disposed radially outward of the cylindrical portion 2421 along the outer circumferential surface of the cylindrical portion 2421. The annular recess 2427 is recessed toward the upstream side in the ink flow direction. When the upstream case 242 and the downstream case 243 are connected, the annular recess 2427 houses the annular rib portion 2437.

[0097] The annular rib portion 2437 sandwiches the inner seal member 244 between itself and the cylindrical portion 2421 of the upstream case 242 in a direction perpendicular to the radial direction Dr (the reciprocating direction of the diaphragm 213) of the output shaft 211x. In other words, the downstream case 243 has the annular rib portion 2437 that sandwiches the inner seal member 244 between itself and the upstream case 242. Note that the annular rib portion may be provided on the upstream case 242, and the inner seal member 244 may be sandwiched between the annular rib portion of the upstream case 242 and the downstream case 243.

[0098] According to the above configuration, it is possible to prevent ink leakage from the connecting portion between the upstream case 242 and the downstream case 243. Therefore, it is possible to suppress a decrease in ink transport performance, and further to prevent ink contamination inside the inkjet recording apparatus 1.

[0099] The ink supply device 20 also includes two outer seal members 25A and 25B. The two outer seal members 25A and 25B are O-rings made of an elastic body such as rubber.

[0100] The outer seal member 25A is disposed between the filter unit 24 and the suction unit 22. In detail, the outer seal member 25A is disposed between the outer edge of the upstream part of the ink flow direction of the cylindrical portion 2421 of the filter unit 24 and the inner edge of the opening 222b of the suction unit 22.

[0101] The outer seal member 25B is disposed between the filter unit 24 and the discharge unit 23. To be more specific, the outer seal member 25B is disposed between the outer edge of the downstream part in the ink flow direction of the cylindrical portion 2431 of the filter unit 24 and the inner edge of the opening 232a of the discharge unit 23.

[0102] The two outer seal members 25A, 25B are disposed between the filter unit 24 and the suction unit 22 and between the filter unit 24 and the discharge unit 23, 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.

[0103] 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.

[0104] 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.

[0105] 12, 14, and 15, 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.

[0106] 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 2422 of the upstream case 242 and the flat plate portion 2432 of the downstream case 243. The unit positioning holes 245 do not communicate with the inside of the cylindrical portion 2421 and the inside of the cylindrical portion 2431. The four unit positioning shafts 234 are individually inserted into the four unit positioning holes 245, respectively.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] According to the above configuration, it is possible to properly position the suction unit 22, the filter unit 24, and the discharge unit 23 with respect to the diaphragm pump 21 (the diaphragm housing portion 216). It is also possible to prevent ink from leaking from the connection portions between the suction unit 22, the filter unit 24, the discharge unit 23, and the diaphragm housing portion 216.

[0113] 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. 18 is a perspective view of the plate-shaped member 27 of the ink supply device 20 in FIG. 6.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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. [Industrial Applicability]

[0118] The present invention can be used in a liquid supplying apparatus and an inkjet recording apparatus. [Explanation of symbols]

[0119] 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 24 Filter Unit 25A, 25B 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 231 Discharge housing 232 Outflow chamber 233 Discharge check valve 234 Unit positioning shaft 241 Filters 242 Upstream Case 243 Downstream Case 244 Inner seal material 245 Unit positioning hole 271 Plate-shaped member positioning hole 2421 Cylindrical part 2422 Flat plate part 2423 Upstream holding section 2424 Upstream facing part 2425 Upstream flow hole 2426 Upstream protrusion 2427 Annular recess 2431 Cylindrical part 2432 Flat plate part 2433 Downstream holding section 2434 Downstream facing part 2435 Downstream flow hole 2436 Downstream protrusion 2437 Circular rib 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; a filter unit disposed between the suction unit and the discharge unit and having a filter covering a cross section of the liquid; Equipped with the suction unit and the discharge unit are arranged one on top of the other with the filter unit sandwiched therebetween such that the inflow chamber and the outflow chamber face the diaphragm on one side in a reciprocating direction of the diaphragm, The filter unit comprises: The filter; an upstream case and a downstream case sandwiching the filter from the upstream side and downstream side in a liquid flow direction relative to the filter; an inner seal member disposed between the upstream case and the downstream case, the inner seal member preventing leakage of the liquid from the filter unit to the outside; A liquid supply device comprising:

2. 2. The liquid supplying device according to claim 1, wherein the suction unit, the discharge unit, and the filter unit are detachable from one another.

3. 2. The liquid supply device according to claim 1, wherein one of the upstream case and the downstream case has an annular rib portion that sandwiches the inner seal member between the upstream case and the downstream case and the other case.

4. 2. The liquid supply device according to claim 1, further comprising two outer seal members disposed between the filter unit and the suction unit and between the filter unit and the discharge unit, respectively, for preventing leakage of the liquid to the outside.

5. The upstream case is an upstream holding portion that is in contact with the downstream case across an outer periphery of a liquid flow path of the filter; an upstream opposing portion that is located inside the liquid flow path with respect to the upstream holding portion, is spaced apart from the filter on the upstream side of the liquid flow direction, and faces the filter in the liquid flow direction; a plurality of upstream flow holes formed in the upstream facing portion, through which the liquid flows; a plurality of upstream protrusions formed on the upstream facing portion and protruding toward the filter; The liquid supply device according to claim 1 , further comprising:

6. The downstream case is a downstream holding portion that is in contact with the upstream case across an outer periphery of a liquid flow path of the filter; a downstream side opposing portion that is located inside the liquid flow path with respect to the downstream side holding portion, is spaced from the filter downstream in the liquid flow direction, and faces the filter in the liquid flow direction; a plurality of downstream flow holes formed in the downstream opposing portion and through which the liquid flows; A plurality of downstream protrusions formed on the downstream opposing portion and protruding toward the filter; The liquid supply device according to claim 1 , further comprising:

7. 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 filter 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 filter 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.

8. 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.

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

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

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

Images