Peristaltic pump and blood purification device using same

Abstract

A peristaltic pump 1 comprises a stator 2 in which are formed an inlet-side tube holding part 24 and an outlet-side tube holding part 25 for holding a tube 7, wherein the tube 7, which is accommodated in a tube accommodating part 23 between the stator 2 and a rotor 3, is compressed while also being squeezed in the longitudinal direction as the rotor 3 rotates, thereby causing a fluid to flow inside the tube 7. By holding the tube 7 at both tube holding parts 24, 25 and rotating the rotor 3, the tube 7 is automatically drawn into the tube accommodating part 23 by a guide roller 32 of the rotor 3. A lock mechanism 6 is provided to lock a cover 3 to the stator 2 while the cover 3 is closed. The lock mechanism 6 is configured to lock automatically when the cover 5 is closed.

Description

Peristaltic pump and blood purification device using same

[0001] The present invention relates to a peristaltic pump and a blood purification device using the same.

[0002] Conventionally, peristaltic pumps have been used as fluid pumps for blood pumps in blood purification systems, etc. A known peristaltic pump has a stator and a rotor, and a flexible tube disposed between the stator and the rotor is compressed and squeezed in the longitudinal direction to move a fluid through the tube.

[0003] In peristaltic pumps, the tube must be set in the correct position. In recent years, autoloading peristaltic pumps have been used in which the tube is set in the stator and then the rotor is rotated, automatically drawing the tube between the stator and rotor and setting it in the correct position (see, for example, Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2020-103642

[0005] Conventional peristaltic pumps have a cover to close the opening at the top of the stator, and this cover is fixed to the stator with a magnet. In autoloading peristaltic pumps, multiple guide rollers that rotate with the rotor press the tubing downward. However, the downstream portion of the tubing (the outlet side of the stator) is positioned above the other guide rollers, creating a relatively sharp bend in the tubing. This can cause a portion of the tubing to bounce upward and push the cover open. Peristaltic pumps used as infusion pumps in blood purification systems are often controlled to forcibly stop operation when the cover opens. Therefore, there is a need to prevent unintentional cover opening during autoloading to improve user convenience.

[0006] Therefore, an object of the present invention is to provide a peristaltic pump that can prevent the cover from opening unintentionally and improve user convenience, and a blood purification device using the same.

[0007] A peristaltic pump according to one embodiment of the present invention comprises a stator having a bottom wall and a side wall surrounding the periphery of the bottom wall, the stator being formed in a box shape with an opening on a surface facing the bottom wall, the side wall being formed with notched inlet and outlet tube holding portions for holding flexible tubes for allowing a fluid to flow, a rotor rotatably provided within the stator such that the normal direction of the bottom wall surface coincides with the rotation axis, a motor for rotating the rotor, and a cover attached to the stator in an openable and closable manner to close the opening when closed. The tubes housed in tube housing portions formed between the side wall of the stator and the rotor are inserted between the side wall and the rotor. The rotor is configured to compress the tube between itself and the stator and squeeze it longitudinally as the rotor rotates, causing the fluid to flow within the tube, the rotor has a plurality of guide rollers spaced apart in the circumferential direction, each having a rotation axis aligned with the radial direction of the rotor, and is configured so that the tube is automatically drawn into the tube accommodating section by the guide rollers when the rotor is rotated with the tube held by the inlet side tube holding section and the outlet side tube holding section, and is provided with a locking mechanism that locks the cover to the stator when the cover is closed, and the locking mechanism is configured so that the locking is performed automatically when the cover is closed.

[0008] A blood purification apparatus according to one embodiment of the present invention uses the peristaltic pump as a liquid delivery pump.

[0009] According to the present invention, it is possible to provide a peristaltic pump and a blood purification device using the same that can prevent the cover from opening unintentionally and improve convenience for the user.

[0010] 8A is a schematic diagram of a blood purification device using a peristaltic pump according to one embodiment of the present invention; FIG. 9 is a perspective view of a peristaltic pump; FIG. 10 is an exploded perspective view of a peristaltic pump; FIG. 11 is a perspective view of a peristaltic pump without a cover; FIG. 12 is a top view of FIG. 4; FIG. 13 is a top view showing a state in which a tube is set in FIG. 5A; FIG. 14 is a diagram explaining autoloading; FIG. 15 is a perspective view of a cover; FIG. 16 is a schematic diagram explaining the position of a protrusion; FIG. 17 is a view showing a protrusion as viewed from arrow A in FIG. 8A; FIG. 18 is a view showing a protrusion as viewed from arrow B in FIG. 8B.

[0011] [Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0012] 1 is a schematic diagram of a blood purification apparatus 100 using a peristaltic pump 1 according to this embodiment. As shown in Fig. 1, the blood purification apparatus 100 is an apparatus that performs blood purification treatment via a blood purifier 101, and includes a dialysate supply / discharge unit 102 that supplies dialysate to the blood purifier 101 and discharges waste fluid from the blood purifier 101, and an extracorporeal circulation unit 103 that circulates the blood of a patient C extracorporeally via the blood purifier 101.

[0013] The blood purifier 101 is also called a dialyzer and contains a blood purification membrane (for example, a hollow fiber hemodialysis membrane, a hemodiafiltration membrane, a flat membrane hemodialysis membrane, or a hemofiltration membrane). The blood purifier 101 purifies blood by bringing blood into contact with a dialysate via the blood purification membrane. The blood purifier 101 has a blood inlet 101a for introducing blood and a blood outlet 101b for discharging the introduced blood, as well as a dialysate inlet 101c for introducing dialysate and a dialysate outlet 101d for discharging the introduced dialysate.

[0014] The dialysate supply / discharge unit 102 has a supply-side pipe 102a connected to the dialysate inlet 101c for supplying the dialysate to the blood purifier 101, and a discharge-side pipe 102b connected to the dialysate outlet 101d for discharging the effluent from the blood purifier 101. The dialysate supply / discharge unit 102 controls the amount of water removed from the blood by controlling the amount of dialysate supplied and the amount of effluent discharged. Although not shown, the dialysate supply / discharge unit 102 may have, for example, a pure water production unit that produces pure water, a dialysate preparation unit that prepares the dialysate from pure water and a dialysate agent, or the like.

[0015] The extracorporeal circulation unit 103 has blood piping (blood circuit) 104 that can circulate the blood of patient C extracorporeally. The blood piping 104 has an arterial blood piping 104a that guides blood collected from the patient C's blood vessels to the blood inlet 101a of the blood purifier 101, and a venous blood piping 104b that returns blood discharged from the blood outlet 101b of the blood purifier 101 to the patient C. The extracorporeal circulation unit 103 has a blood pump 105 that is disposed in the arterial blood piping 104a and circulates the blood. The blood pump 105 is composed of a peristaltic pump 1 according to this embodiment. Although not shown, the extracorporeal circulation section 103 is provided in the venous blood piping 104b and is equipped with a venous pressure detector that measures the pressure of the blood flowing through the blood piping 104, an air bubble detector that detects air bubbles in the blood, and a flow path blocking mechanism that blocks the venous blood piping 104b to interrupt the extracorporeal circulation of blood when an abnormality occurs, such as when air bubbles are detected by the air bubble detector.

[0016] (Peristaltic Pump 1) The peristaltic pump 1 according to this embodiment is used as the blood pump 105 of the blood purification apparatus 100. However, the use of the peristaltic pump 1 is not limited to this, and it may also be used as other fluid delivery pumps, such as a fluid replacement pump. The peristaltic pump 1 can also be used for purposes other than the blood purification apparatus 100.

[0017] Figure 2 is a perspective view of the peristaltic pump 1, and Figure 3 is an exploded perspective view thereof. As shown in Figures 2 and 3, the peristaltic pump 1 includes a stator 2, a rotor 3 rotatably mounted within the stator 2, a motor 4 that drives the rotor 3, and a cover 5 that closes an opening in the stator 2. The peristaltic pump 1 is configured such that a tube 7 housed in a tube housing portion 23 formed between the stator 2 and the rotor 3 is compressed between a side wall 22 of the stator 2 and the rotor 3, and is squeezed longitudinally as the rotor 3 rotates, thereby causing a fluid such as blood to flow within the tube 7. Each component will be described in detail below.

[0018] (Stator 2) The stator 2 is a component fixed to the housing (not shown) of the blood purification device 100 or the like and does not rotate with the rotation of the rotor 3. The stator 2 has a bottom wall 21 and a side wall 22 surrounding the periphery of the bottom wall 21. The stator 2 is box-shaped with an open (opening upward) surface facing the bottom wall 21. Hereinafter, the rotor 3 side of the bottom wall 21 (the upper side in FIGS. 2 and 3 ) will be referred to as the "upper" side, and the motor side of the bottom wall 21 (the lower side in FIGS. 2 and 3 ) will be referred to as the "lower" side. A through-hole 21a penetrating the bottom wall 21 is formed in the center of the bottom wall 21, and the rotor 3 and motor 4 are connected via this through-hole 21a. The rotation axis of the rotor 3 is perpendicular to the surface of the bottom wall 21. The bottom wall 21 is fixed to the housing (not shown) of the blood purification device 100 or the like by screws or the like.

[0019] Fig. 4 is a perspective view of the peristaltic pump 1 without the cover 5, Fig. 5A is a top view thereof, and Fig. 5B is a top view thereof when the tube 7 is arranged. As shown in Figs. 4, 5A, and 5B, by arranging the rotor 3 inside the stator 2, a tube accommodating portion 23 for accommodating the tube 7 is formed between the side wall 22 of the stator 2 and the rotor 3. By accommodating the tube 7 inside the tube accommodating portion 23 and driving the rotor 3 to rotate, the tube 7 is compressed between the rotor 3 and the side wall 22, and the tube 7 is squeezed in the longitudinal direction as the rotor 3 rotates, causing the fluid in the tube 7 to flow.

[0020] Furthermore, in the peristaltic pump 1 according to this embodiment, a mechanism for holding the tube 7 at the inlets and outlets where the tube 7 is introduced into or led out of the stator 2 is provided integrally with the stator 2. The stator 2 has a side wall 22 formed with notched inlet and outlet tube holding portions 24 and 25 for holding the tube 7. The inlet and outlet tube holding portions 24 and 25 have linear grooves 241 and 251 for guiding the tube 7. The grooves 241 and 251 open upward, and by pressing the lower portion of the tube 7 into the grooves 241 and 251, the tube 7 is guided to the correct position at the inlet and outlet portions of the peristaltic pump 1.

[0021] The inlet-side tube holding portion 24 and the outlet-side tube holding portion 25 have a pair of protrusions 242, 252 at their outer ends to prevent the tube 7 from slipping out upward. The pair of protrusions 242, 252 are provided facing each other in a direction perpendicular to the longitudinal direction of the tube 7 at the top of the held tube 7. The tube 7 is set in the inlet-side tube holding portion 24 and the outlet-side tube holding portion 25 by passing the tube 7 between the pair of protrusions 242, 252 while deforming it and pushing it from above to below.

[0022] The side wall 22 around the tube accommodating portion 23 is formed in a circular shape (arc shape) centered on the rotation axis of the rotor 3 in a top view. The tube 7 is configured to be bent between the inlet tube holding portion 24 and the tube accommodating portion 23 when the tube 7 is accommodated in the inlet tube holding portion 24 and the tube accommodating portion 23. The side wall 22 between the inlet tube holding portion 24 and the tube accommodating portion 23 is curved so as to convex inward to follow the curvature of the tube 7. Details of the inlet tube holding portion 24 and the inclined surface 26 formed on the side wall 22 will be described later.

[0023] (Rotor 3) The rotor 3 is rotatably provided within the stator 2 so that the normal direction to the surface of the bottom wall 21 coincides with its rotation axis. The rotor 3 has a plurality of (here, two) rollers 31 that rotate integrally with the rotor 3 and have rotation axes parallel to the rotation axis of the rotor 3. The distance between the rollers 31 and the side wall 22 of the stator 2 is set to be smaller than the outer diameter of the tube 7. The rollers 31 are also biased radially outward from the rotor 3. As a result, when the rotor 3 is rotated, the rollers 31 compress and squeeze the tube 7, causing the fluid in the tube 7 to flow.

[0024] The rotor 3 also has a plurality of guide rollers 32 spaced apart in the circumferential direction, each having a rotation axis aligned along the radial direction of the rotor 3. Here, first guide rollers 32a, which are longer in the radial direction of the rotor 3, and second guide rollers 32b, which are shorter in the radial direction of the rotor 3 than the first guide rollers 32a, are arranged alternately in the circumferential direction of the rotor 3. The guide rollers 32 are also provided facing each other above and below in the axial direction of the rotor 3. Here, a total of eight guide rollers 32 are provided, four at the top and four at the bottom. These guide rollers 32 hold the tube 7 in the correct position within the tube accommodating portion 23 and serve to prevent the tube 7 from slipping out upward, for example.

[0025] Furthermore, the two first guide rollers 32a provided on the upper part of the rotor 3 also serve to draw the tube 7 into the tube housing portion 23 when the tube 7 is set. More specifically, the tube 7 is first set and held in the inlet-side tube holding portion 24 and the outlet-side tube holding portion 25. Then, as shown in Figure 6, when the rotor 3 is rotated, the first guide rollers 32a sequentially push the tube 7 downward, and the tube 7 is automatically drawn into the tube housing portion 23 (hereinafter, this operation is referred to as auto-loading). In this way, the peristaltic pump 1 according to this embodiment is an auto-loading type peristaltic pump that has the function of automatically setting the tube 7 in the correct position.

[0026] If the first guide roller 32a is located near the entrance of the tube storage section 23, the first guide roller 32a may get in the way and make it difficult to set the tube 7. Therefore, when stopping the rotor 3, the first guide roller 32a may be controlled to stop the rotor 3 at a position where it does not get in the way of setting the tube 7.

[0027] (Motor 4) The motor 4 drives the rotor 3 to rotate. The motor 4 is disposed outside the stator 2. The motor 4 is disposed so that the rotor 3 and the motor 4 sandwich the bottom wall 21 of the stator 2, and is coupled to the motor 4 via a through-hole 21a formed in the bottom wall 21. When the bottom wall 21 of the stator 2 is attached to the housing of the blood purification device 100, the motor 4 will be disposed inside the housing.

[0028] (Cover 5) Figure 7 is a perspective view of the cover 5. The cover 5 is attached to the stator 2 via a hinge portion 51 so as to be able to open and close, and is configured to close the opening at the top of the stator 2 when the cover 5 is in a closed state. The cover 5 is made of a material that transmits visible light (a so-called transparent material) so that the internal state, such as the state of the tubes 7, can be confirmed.

[0029] In this embodiment, when the cover 5 is closed, the gap formed between the top of the rotor 3 and the cover 5 (the width of the gap along the axial direction of the rotor 3) is smaller than twice the thickness of the tube 7. This makes it impossible to close the cover 5 with the tube 7 sandwiched between the rotor 3 and the cover 5, making it possible to prevent the tube 7 from being pinched.

[0030] The peristaltic pump 1 also has a cover closure detection means 8 that detects whether the cover 5 is closed. In this embodiment, a cover detection protrusion 52 protruding downward from the cover 5 is provided, and a magnet (not shown) is attached to the tip of the cover detection protrusion 52. The stator 2 is provided with a reed switch (not shown) that is turned on by the magnet when the cover 5 is closed. When the reed switch is turned on, the peristaltic pump 1 detects that the cover 5 is closed. The rotor 3 can be rotated only when the cover 5 is closed. In this embodiment, the rotor 3 is automatically rotated for a predetermined period of time when the cover 5 is closed, thereby performing autoloading. This allows the tube 7 to be automatically set when the cover 5 is closed.

[0031] (Locking Mechanism 6) The peristaltic pump 1 according to this embodiment includes a locking mechanism 6 that locks the cover 5 to the stator 2 when the cover 5 is closed. The locking mechanism 6 keeps the cover 5 closed to prevent unintentional opening. Furthermore, in this embodiment, the locking mechanism 6 is configured to automatically lock the cover 5 when it is closed. As described above, the peristaltic pump 1 employs an autoloading system, and the tube 7 tends to bounce upward during autoloading. Therefore, if the cover 5 is secured to the stator 2 by a magnet, for example, there is a risk that the bounced-up tube 7 may push the cover 5 open unintentionally. By providing the locking mechanism 6 on the cover 5 as in this embodiment, it is possible to prevent the cover 5 from opening unintentionally during autoloading. Furthermore, the locking mechanism 6 is configured to lock the cover 5 with a single touch by simply closing the cover 5, which reduces user effort and provides high convenience.

[0032] More specifically, the locking mechanism 6 has an engaged portion 61 formed on the side wall 22 of the stator 2, a retractable engaging portion 62 formed on the cover 5 and engaged with the engaged portion 61, and a biasing member (not shown) that biases the engaging portion 62 in the direction of engaging with the engaged portion 61. Here, the engaging portion 62 is formed by a latch 621 rotatably provided on the cover 5, and the biasing member is formed by a torsion spring that biases the latch 621 to rotate in the engaging direction. The engaged portion 61 is configured such that a metal bar 611 that can engage the latch 621 is attached to the stator 2. When the cover 5 is closed, the claw of the latch 621 automatically rides up onto the bar 611 and is engaged, locking the cover 5 to the stator 2. To release the lock, the upper part of the latch 621 (the end opposite the claw) is pressed to rotate the latch 621 in the direction opposite to the locking direction against the biasing force of the biasing member, and in this state, the cover 5 is moved upward. Note that here, the locked part 61 is formed on the stator 2 side and the locking part 62 is formed on the cover 5 side, but this is not limiting, and the locking part 62 may be formed on the stator 2 side and the locked part 61 on the cover 5 side. In other words, the locked part 61 may be formed on one of the side wall 22 of the stator 2 and the cover 5, and the locking part 62 may be formed on the other of the side wall 22 of the stator 2 and the cover 5.

[0033] In this embodiment, the locking mechanism 6 is configured to fix and lock the cover 5 to the side wall 22 between the inlet-side tube holding portion 24 and the outlet-side tube holding portion 25 when the cover 5 is closed. As will be described in detail later, in this embodiment, the tube 7 is pressed downward by the protrusions 53, 54 provided on the cover 5 at two locations, near the inlet-side tube holding portion 24 and near the outlet-side tube holding portion 25, and therefore the force (reaction force) trying to open the cover 5 may be particularly large at these two locations. Therefore, by locking the cover 5 at positions close to these two locations, it is possible to more stably hold the cover 5 in the closed state.

[0034] The specific structure of the locking mechanism 6 is not limited to that shown in the drawings and can be modified as appropriate. However, in consideration of convenience, it is desirable to configure the locking mechanism 6 so that it automatically (with one touch) locks by simply closing the cover 5. Furthermore, in this embodiment, the locking mechanism 6 is configured so that mechanical locking is automatically performed when the cover 5 is closed, but this is not limiting, and the locking mechanism 6 may also be configured so that electromagnetic locking is automatically performed when the cover 5 is closed.

[0035] (Protrusion 53 and Inclined Surface 26) The tube 7 is flexible and may be stored, for example, in a wound state, which may cause the tube 7 to have a tendency to bend. Therefore, even if the tube 7 is set in both the inlet-side tube holding portion 24 and the outlet-side tube holding portion 25, the tube 7 may float above the inlet-side tube holding portion 24, preventing the first guide roller 32a from properly pushing the tube 7 downward, resulting in a failure of autoloading. Therefore, in this embodiment, a downwardly protruding protrusion 53 is provided on the cover 5 at a portion facing the inlet-side tube holding portion 24. This protrusion 53 is configured to push the tube 7 downward and into the inlet-side tube holding portion 24 when the cover 5 is closed.

[0036] 8A and 8B , in this embodiment, the protrusion 53 is formed in an H-shape when viewed from above (a plan view from one side of the rotation axis of the rotor 3). The protrusion 53 has a pair of flat plates 531 parallel to the central axis O of the tube 7 (or the central axis of the groove 241) when the tube 7 is properly positioned in the inlet-side tube holding portion 24. The centers of the pair of flat plates 531 are connected by a connecting edge 532, forming an overall H-shape. This increases the contact area between the protrusion 53 and the tube 7, making it possible to prevent the tube 7 from being crushed by the pressure of the protrusion 53. In this embodiment, because the inlet-side tube holding portion 24 is formed at an angle (described in detail below), the tip of the protrusion 53, i.e., the lower end of the flat plate 531, is also formed at an angle (inclined so as to protrude downward as it approaches the rotor 3) to be parallel to the angle of the inlet-side tube holding portion 24.

[0037] If the tube 7 climbs up onto the side wall 22, it may be possible that the tube 7 will be crushed between the upper surface of the side wall 22 and the protrusion 53 when the cover 5 is closed, making it impossible to guide the tube 7 to the inlet-side tube holding portion 24. In particular, in this embodiment, the tube 7 is configured to be bent between the inlet-side tube holding portion 24 and the tube accommodating portion 23 when the tube 7 is accommodated in the tube accommodating portion 23. This makes it easy for the tube 7 to climb up onto the side wall 22 so as to shortcut this bent portion. Therefore, in this embodiment, at least the end of the side wall 22 along the bent portion of the tube 7 on the cover 5 side (i.e., the upper portion of the side wall 22) is formed with an inclined surface 26 for guiding the tube 7 to the inlet-side tube holding portion 24 as the protrusion 53 presses it downward.

[0038] The inclined surface 26 is inclined so as to approach the bottom wall 21 as it approaches the inlet-side tube holding portion 24. The inclined surface 26 is formed by chamfering the upper corners of the side wall 22 and the inner corners of the stator 2. The inclined surface 26 is also formed with at least one (in the illustrated example, multiple) convex, linear (straight) rib 27 along the inclination direction. This reduces the contact area of ​​the tube 7 with the side wall 22, allowing the tube 7 to slide (or rotate) on the rib 27 and be guided to the inlet-side tube holding portion 24 as the protrusion 53 presses downward. The number of ribs 27 is not particularly limited, but it is preferable to set the number of ribs 27 taking into consideration the area of ​​the inclined surface 26, the material of the stator 2, and the ease of sliding of the tube 7, so that the tube 7 can be easily guided to the inlet-side tube holding portion 24. In addition to the ribs, a protrusion, such as a hemispherical protrusion, may be provided as appropriate to guide the tube 7 to the inlet-side tube holding portion 24.

[0039] Furthermore, in this embodiment, the protrusions 53 are formed so that, in a top view (a plan view seen from one side of the rotation axis of the rotor 3), their centers are offset toward the inclined surface 26 with respect to the central axis O of the tube 7 when the tube 7 is correctly positioned in the inlet tube holding portion 24. As described above, the tube 7 tends to climb up onto the side wall 22 to shortcut the bent portion, so by forming the protrusions 53 offset toward the inclined surface 26, it becomes easier to guide the tube 7 into the inlet tube holding portion 24. Furthermore, although a force is required to push the tube 7 in when closing the cover 5, forming the protrusions 53 offset allows the cover 5 to be closed with a relatively weak force.

[0040] In this embodiment, the pair of flat plates 531 of the protrusion 53 have the same protrusion length, but the pair of flat plates 531 may have different protrusion lengths. In this case, as shown in FIG. 9 , the protrusion length of the flat plate 531 on the inclined surface 26 side may be longer than the protrusion length of the other flat plate 531. This allows the protrusion length of the flat plate 531 to follow the outer shape of the tube 7 depending on the positional deviation between the central axis O of the tube 7 and the center of the protrusion 53, thereby increasing the contact area of ​​the protrusion 53 with the tube 7 and further suppressing crushing of the tube 7. To improve the sliding of the tube 7, the stator 2 is preferably made of a slippery material such as polyacetal resin.

[0041] In this embodiment, similar to the inlet-side tube holding portion 24 side, the outlet-side tube holding portion 25 side also has a downwardly projecting protrusion 54 on the cover 5 at the portion facing the outlet-side tube holding portion 25, and this protrusion 54 is configured so that when the cover 5 is closed, the tube 7 is pushed downward and into the outlet-side tube holding portion 25. This makes it possible to automatically set the tube 7 in the correct position even if, for example, the tube 7 is not firmly set in the outlet-side tube holding portion 25 and is floating. However, the protrusion 54 is not essential and can be omitted.

[0042] (Regarding the Inclination of the Inlet-Side Tube Holding Portion 24) To prevent autoloading failures caused by the influence of the bending tendency of the tube 7 or an improper installation of the tube 7, in this embodiment, the inlet-side tube holding portion 24 is inclined by 1° or more with respect to a plane perpendicular to the rotation axis of the rotor 3 so as to gradually approach the bottom wall 21 from the outside to the inside of the stator 2 (toward the rotor 3). This causes the tube 7 to be held in an inclined state such that it is guided downward as it approaches the rotor 3, making autoloading failures less likely to occur even if the tube 7 has a significant bending tendency. The outlet (the end on the rotor 3 side) of the groove 241 of the inlet-side tube holding portion 24 is adjusted so that the entire tube 7 is lower than the first guide roller 32a when the tube 7 is held.

[0043] To further reduce the risk of autoloading failures, the inclination angle of the inlet-side tube holding portion 24 (the inclination angle with respect to a plane perpendicular to the rotation axis of the rotor 3) is preferably 5° or greater, and more preferably 10° or greater. In this embodiment, the inclination angle of the inlet-side tube holding portion 24 is set to 15°. However, if the inclination angle of the inlet-side tube holding portion 24 is too large, the tube 7 may be positioned too close to the bottom wall 21 in the tube accommodating portion 23, resulting in an inability to accommodate the tube 7 in the correct position. Furthermore, the tube 7 may be significantly lifted outside the stator 2. Therefore, the inclination angle of the inlet-side tube holding portion 24 should be 45° or less, and more preferably 30° or less.

[0044] 5B , in a top view (plan view seen from one side of the rotation axis of the rotor 3), the inlet-side tube holding portion 24 is inclined toward the rotation axis of the rotor 3 with respect to a tangent T passing through the central axis of the inlet of the inlet-side tube holding portion 24 (the intersection of the outer end of the groove 241 and the central axis of the groove 241), among tangents to the central axis O of the tube 7 when the tube 7 is housed in the tube housing portion 23. In other words, the inlet-side tube holding portion 24 is formed so as to gradually approach the outlet-side tube holding portion 25 from the outside to the inside of the stator 2. This increases the bending angle of the tube 7 between the inlet-side tube holding portion 24 and the tube housing portion 23, making it easier for the tube 7 to approach the rotor 3. This makes it easier for the first guide roller 32 a to push the tube 7 downward, thereby further reducing failures in autoloading of the tube 7.

[0045] (Functions and Effects of the Embodiment) As described above, the peristaltic pump 1 according to the present embodiment is provided with the locking mechanism 6 that locks the cover 5 to the stator 2 when the cover 5 is closed, and the locking mechanism 6 is configured to automatically lock when the cover 5 is closed. This makes it possible to prevent the cover 5 from opening unintentionally due to the tube 7 bouncing up during autoloading. Furthermore, because the cover 5 can be locked simply by closing the cover 5, user convenience is improved, and a peristaltic pump 1 that is easy to handle can be realized.

[0046] Furthermore, in this embodiment, the locking mechanism 6 has an engaged portion 61 formed on one of the side wall 22 of the stator 2 and the cover 5, an engaging portion 62 formed on the other of the side wall 22 of the stator 2 and the cover 5 and movable to engage with the engaged portion 61, and a biasing member that biases the engaging portion 62 in the direction of engaging with the engaged portion 61, so that when the cover 5 is closed, the engaging portion 62 automatically engages with the engaged portion 61, thereby locking. This allows the locking mechanism 6 to be realized with a relatively simple structure.

[0047] In this embodiment, the locking mechanism 6 is configured to engage with the side wall 22 between the inlet tube holding portion 24 and the outlet tube holding portion 25 when the cover 5 is closed, thereby locking the cover 5. This makes it possible to hold the cover 5 in the closed state more firmly.

[0048] Furthermore, in this embodiment, the gap formed between the rotor 3 and the cover 5 when the cover 5 is closed is smaller than twice the thickness of the tube 7. This makes it impossible to close the cover 5 with the tube 7 sandwiched between the rotor 3 and the cover 5, thereby preventing the tube 7 from being pinched.

[0049] (Note) Although the embodiments of the present invention have been described above, the invention according to the claims is not limited to the above-described embodiments. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention. Furthermore, the present invention can be implemented with appropriate modifications within the scope of its spirit.

[0050] DESCRIPTION OF SYMBOLS 1...peristaltic pump 2...stator 21...bottom wall 21a...through hole 22...side wall 23...tube accommodating section 24...inlet side tube holding section 25...outlet side tube holding section 241, 251...groove 242, 252...projection 26...inclined surface 27...rib 3...rotor 31...roller 32...guide roller 32a...first guide roller 32b...second guide roller 4...motor 5...cover 51...hinge section 52...cover detection projection 53...projection 531...flat plate 532...connecting side 54...projection 6...locking mechanism 61...engaged section 611...bar 62...engaging section 621...latch 7...tube

Claims

1. A stator having a bottom wall and side walls surrounding the periphery of the bottom wall, formed in a box shape with an open surface facing the bottom wall, and having notched inlet and outlet tube holding portions formed in the side walls to hold flexible tubes for allowing fluid to flow; a rotor rotatably provided within the stator so that the normal direction of the bottom wall surface coincides with the rotation axis; a motor for driving the rotor to rotate; and a cover attached to the stator so as to be able to open and close, and which covers the opening when closed; wherein the tube accommodated in a tube accommodating portion formed between the side wall of the stator and the rotor is compressed between the side wall and the rotor, and squeezed in the longitudinal direction as the rotor rotates, thereby causing fluid to flow within the tube. The rotor has a plurality of guide rollers spaced apart circumferentially, each having a rotation axis aligned radially of the rotor, and is configured so that by rotating the rotor while the tube is held in the inlet side tube holding portion and the outlet side tube holding portion, the tube is automatically drawn into the tube accommodating portion by the guide rollers; the pump is further provided with a locking mechanism that locks the cover to the stator when the cover is closed, and the locking mechanism is configured to automatically lock the cover when the cover is closed.

2. The peristaltic pump according to claim 1, wherein the locking mechanism comprises an engaged portion formed on one of the side walls of the stator and the cover, a movable engaging portion formed on one of the side walls of the stator and the cover and engaged with the engaged portion, and a biasing member that biases the engaging portion in the direction of engagement with the engaged portion, and is configured so that when the cover is closed, the engaging portion automatically engages with the engaged portion, thereby achieving the locking.

3. The peristaltic pump according to claim 1, wherein the locking mechanism is configured to engage with the side wall between the inlet tube holding portion and the outlet tube holding portion when the cover is closed, thereby achieving the locking.

4. The peristaltic pump according to claim 1, wherein a gap formed between the rotor and the cover when the cover is closed is smaller than twice the thickness of the tube.

5. A blood purification device using the peristaltic pump according to any one of claims 1 to 4 as a liquid delivery pump.

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