JP2012057525A - Tube pump and fluid injection recording device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tube pump which enables cost reduction of a device and simplification of the configuration, and can be explosion proofed, and which can restrain progress of degradation of the tube and reduce variations in suction pressure and discharge pressure, and a fluid injection recording device having the same.SOLUTION: A tube pump M is configured to pressure-feed fluid inside a tube 102 by moving a roller 103 while squeezing the tube 102. The roller 103 is provided with an oil damper 121 which can displace the roller 103, according to a force acting on the roller 103 from the tube 102, toward a direction such that the roller 103 approaches/separates to/from the tube 102.

Description

  The present invention relates to a tube pump and a liquid jet recording apparatus including the tube pump.

2. Description of the Related Art Conventionally, a liquid jet recording apparatus that records an image, a character, or the like by jetting a liquid such as an ink droplet onto a recording medium such as a recording paper is known. A liquid jet recording apparatus includes a liquid jet head that jets liquid, a carriage that is mounted with the liquid jet head and reciprocates with respect to a recording medium such as recording paper, and a liquid container that supplies liquid to the liquid jet head. I have.
In the liquid jet recording apparatus, when recovering the non-ejection state of the liquid, the liquid jet head is sealed and the liquid is sucked from the jet nozzle, or the liquid is supplied from the liquid container to the liquid jet head. At this time, a tube pump is employed to pressurize the inside of the liquid supply pipe connecting the two (so-called pressurization and filling) and to supply ink (see, for example, Patent Documents 1 to 3).

  The tube pump includes a tube formed along the inner peripheral surface of the case formed in a cylindrical shape, a roller that presses the tube toward the inner peripheral surface of the case, and a roller along the circumferential direction of the inner peripheral surface of the case. And a rotating body that rolls. In this case, when the rotating body is rotated by the motor, the roller rolls along the inner peripheral surface of the case while crushing the tube toward the inner peripheral surface of the case. Thereby, the liquid in the tube pump is pushed out downstream.

JP-A-2005-240575 JP-A-8-28453 Japanese Patent Laid-Open No. 11-19279

By the way, in the tube pump mentioned above, in order to suppress that the pressure in a tube raises rapidly by clogging etc. in a tube, it is necessary to take an explosion-proof measure. As this explosion-proof measure, there is known a configuration in which sensors for detecting the pressure, flow rate, etc. in the tube are provided and the motor is controlled based on the detection results of these sensors, or a flow rate control valve is provided. .
However, in such a configuration, there is a problem that the cost increases due to an increase in parts and the configuration becomes complicated. In addition, since the tube pump for the liquid jet recording apparatus does not require high rotation and high stop accuracy, it is desired to employ a cheaper motor in order to reduce the cost of the apparatus.

In addition, when the tube pump is not used, if one portion of the tube is continuously pressed by the roller, there is a problem that the deterioration of the tube is caused.
Further, in the tube pump, there is a possibility that the pressure in the tube with respect to the pressing force by the roller may vary depending on the manufacturing variation of the tube and case, and there is a problem that the suction pressure and the discharge pressure vary.

  Therefore, the present invention has been made in view of the above-described problems, and can take an explosion-proof measure after reducing the cost of the apparatus and simplifying the configuration, and can further promote the deterioration of the tube. The present invention provides a tube pump that can suppress the variation in suction pressure and discharge pressure, and a liquid jet recording apparatus including the tube pump.

  In order to solve the above-described problems and achieve such an object, a tube pump according to the present invention includes a flexible tube and an axial direction of the tube while pressing the tube from the outside. And a pressing means that moves, while the pressing means moves while crushing the tube, so that the fluid stored in the tube is pumped. In accordance with a force acting on the means, there is provided a pressing force adjusting means capable of displacing the pressing means in a direction approaching and separating from the tube.

  According to this configuration, when the pressure in the tube increases, the pressing force adjusting means is pushed by the tube and displaces the pressing means in a direction away from the tube, so that the tube is restored following this. Therefore, the cross-sectional area of the tube can be enlarged and the pressure in the tube can be relaxed. Therefore, the pressure in the tube can be maintained almost constant. Thereby, explosion-proof measures can be taken without providing sensors for detecting the pressure or flow rate in the tube or providing a flow rate control valve or the like. Therefore, the cost increase of the tube pump can be suppressed and the configuration can be simplified. In addition, since it is not necessary to perform rotation control of the drive motor as an explosion-proof measure, a relatively inexpensive drive motor can be employed. Also by this, the cost increase of a tube pump can be suppressed.

Furthermore, when the tube pump is not used, the pressing of the tube by the pressing unit can be released by displacing the pressing unit in a direction away from the tube. For this reason, since it can prevent that a tube always receives the pressing force by a press means, progress of deterioration of a tube can be suppressed and the lifetime of a tube pump can be extended.
In addition, the fact that the pressure in the tube can be maintained constant means that manufacturing variations of the tube or the like can be absorbed. For this reason, variations in suction pressure and discharge pressure of the tube pump can be reduced.
Moreover, the same pressing force adjusting means can be used for various tubes having different tube diameters and thicknesses by adjusting the pressing force by the pressing means. That is, since parts can be shared, costs can be reduced and manufacturing efficiency can be improved compared to the case where parts suitable for each tube are manufactured separately.

The pressing force adjusting means includes a cylinder filled with oil, a piston movable in the cylinder, one end side connected to the piston, and the other end protruding from the cylinder to support the pressing means. The piston rod is configured to be able to advance and retreat in the cylinder in a direction approaching and separating from the tube.
According to this configuration, since the piston rod is displaced according to the force acting on the pressing means from the tube, the pressure in the tube can be maintained substantially constant.
Moreover, the pressing force of the tube by the pressing means can be changed by changing the pressure in the cylinder. As a result, manufacturing variations in tubes and the like can be absorbed, and variations in suction pressure and discharge pressure of the tube pump during normal use can be reduced.
Further, by changing the pressing force by the pressing means, the same pressing force adjusting means can be used for various tubes having different tube diameters and wall thicknesses. Therefore, compared with the case where parts suitable for each tube are manufactured separately, cost reduction and improvement in manufacturing efficiency can be achieved.
Further, by adjusting the pressure in the cylinder and separating the pressing means from the tube, the pressing of the tube by the pressing means is released. For this reason, the progress of deterioration of the tube can be suppressed, and the life of the tube pump can be extended.

The cylinder includes an inner cylinder in which the piston slides along an axial direction, and an outer cylinder that is coaxial with the inner cylinder and disposed outside.
According to this configuration, by employing a so-called double cylinder type oil damper, a sufficient stroke amount can be ensured even with a small component such as a tube pump.

The pressing force adjusting means includes a cam member attached to the rotating shaft, and a sliding member whose one end side slides on the peripheral surface of the cam member and whose other end side supports the pressing means. The sliding member is configured to be displaceable in a direction approaching and separating from the tube as the cam member rotates.
According to this configuration, since the sliding member is displaced according to the force acting on the pressing means from the tube, the pressure in the tube can be maintained almost constant.
Moreover, the pressing force of the tube by the pressing means can be changed by changing the angle of the cam member. As a result, manufacturing variations in tubes and the like can be absorbed, and variations in suction pressure and discharge pressure of the tube pump during normal use can be reduced.
Further, by changing the pressing force by the pressing means, the same pressing force adjusting means can be used for various tubes having different tube diameters and wall thicknesses. Therefore, compared with the case where the pressing force adjusting means suitable for each tube is manufactured separately, cost reduction and manufacturing efficiency can be improved.
Further, by adjusting the angle of the cam member and separating the pressing means from the tube, the pressing of the tube by the pressing means is released. For this reason, the progress of deterioration of the tube can be suppressed, and the life of the tube pump can be extended.

The pressing force adjusting means includes a spring member that urges the pressing means toward the tube, and an adjustment mechanism that adjusts the urging force of the spring member by adjusting a spring length of the spring member. It is characterized by having.
According to this configuration, the urging means is elastically deformed according to the pressure change in the tube, so that the pressure in the tube can be maintained almost constant.
Moreover, since the biasing force of the spring member can be adjusted by adjusting the spring length of the spring member by the adjusting mechanism, the pressing force of the tube by the pressing means can be changed. As a result, manufacturing variations in tubes and the like can be absorbed, and variations in suction pressure and discharge pressure of the tube pump during normal use can be reduced.
Further, by changing the pressing force by the pressing means, the same pressing force adjusting means can be used for various tubes having different tube diameters and wall thicknesses. Therefore, compared with the case where the pressing force adjusting means suitable for each tube is manufactured separately, cost reduction and manufacturing efficiency can be improved.
Further, by adjusting the urging force of the urging means and separating the pressing means from the tube, the pressing of the tube by the pressing means is released. Thereby, since the progress of deterioration of the tube can be suppressed, the life of the tube pump can be extended.

In the liquid jet recording apparatus of the present invention, the liquid container that contains the liquid, the liquid jet head that jets the liquid, and the liquid in the liquid container toward the liquid jet head through the liquid supply pipe. It has the tube pump of the said this invention pumped.
According to this configuration, since the tube pump of the present invention is provided, it is possible to provide a highly reliable liquid jet recording apparatus while reducing costs and simplifying the apparatus, and to extend the service life. be able to.

  According to the tube pump and the liquid jet recording apparatus according to the present invention, the cost of the apparatus is reduced and the configuration is simplified, and an explosion-proof measure can be taken and the progress of deterioration of the tube can be suppressed. Can be reduced.

FIG. 3 is a perspective view showing a liquid jet recording apparatus. It is a top view of the tube pump in a 1st embodiment. It is sectional drawing of an oil damper. It is operation | movement explanatory drawing at the normal time of the tube pump in 1st Embodiment. It is operation | movement explanatory drawing at the time of the raise of the tube internal pressure in 1st Embodiment. It is operation | movement explanatory drawing of a tube pump. It is operation | movement explanatory drawing of an oil damper. It is sectional drawing which shows the other structure of an oil damper. It is operation | movement explanatory drawing of an oil damper. It is a top view of the tube pump in a 2nd embodiment. It is operation | movement explanatory drawing of a tube pump. It is a top view of the tube pump in a 3rd embodiment. It is a top view which shows the other structure of a tube pump.

(First embodiment)
Next, a first embodiment of the present invention will be described with reference to the drawings.
(Liquid jet recording device)
FIG. 1 is a perspective view showing a liquid jet recording apparatus.
As shown in the figure, the liquid jet recording apparatus 1 includes a pair of transport means 2 and 3 for transporting a recording medium S such as paper, a liquid jet head 4 for jetting liquid onto the recording medium S, and a liquid jet. A liquid supply unit 5 that supplies liquid to the head 4 and a scanning unit 6 that scans the liquid ejecting head 4 in a direction (sub-scanning direction) substantially orthogonal to the conveyance direction (main scanning direction) of the recording medium S are provided. Yes. Hereinafter, the sub-scanning direction will be described as the X direction and the main scanning direction as the Y direction.

  The pair of conveying means 2 and 3 includes grid rollers 20 and 30 extending in the X direction, and pinch rollers 21 and 31 extending in parallel along the grid rollers 20 and 30, respectively, although details are not shown. And a drive mechanism such as a motor for rotating the grid rollers 20 and 30 around the axis.

  The liquid supply means 5 includes a liquid container 50 that stores liquid, and a liquid supply pipe 51 that connects the liquid container 50 and the liquid jet head 4. A plurality of liquid containers 50 are provided. Specifically, liquid tanks 50Y, 50M, 50C, and 50B that store four kinds of liquids of yellow, magenta, cyan, and black are provided side by side. A tube pump M is provided in each of the liquid tanks 50Y, 50M, 50C, and 50B, and the liquid can be pressed and moved to the liquid ejecting head 4 through the liquid supply pipe 51. The liquid supply pipe 51 is formed of a flexible hose having flexibility that can correspond to the operation of the liquid ejecting head 4 (carriage unit 62).

  The scanning means 6 extends in the X direction, a pair of guide rails 60, 61, a carriage unit 62 slidable along the pair of guide rails 60, 61, and moves the carriage unit 62 in the X direction. And a drive mechanism 63. The drive mechanism 63 rotates a pair of pulleys 64 and 65 disposed between the pair of guide rails 60 and 61, an endless belt 66 wound between the pair of pulleys 64 and 65, and one pulley 64. And a drive motor 67 to be driven.

  The pair of pulleys 64 and 65 are disposed between both ends of the pair of guide rails 60 and 61, respectively, and are disposed with an interval in the X direction. The endless belt 66 is disposed between the pair of guide rails 60 and 61, and a carriage unit 62 is connected to the endless belt 66. A plurality of liquid jet heads 4 are mounted on the base end portion 62a of the carriage unit 62. Specifically, the liquid jet heads 4Y and 4M individually correspond to four types of liquids of yellow, magenta, cyan, and black. , 4C, 4B are mounted side by side in the sub-scanning direction.

(Tube pump)
FIG. 2 is a plan view of the tube pump.
As shown in the figure, the tube pump M of this embodiment includes a housing 101, a flexible tube 102 arranged along the inner peripheral surface of the housing 101, and the tube 102 connected to the inner periphery of the housing 101. A pair of rollers (pressing means) 103 that presses toward the surface and a rotating body 104 that rolls each roller 103 along the inner peripheral surface of the housing 101 are provided.

The housing 101 is a U-shaped member in plan view, and an inner peripheral surface of the housing 101 is formed in an arc shape around a predetermined angle range (for example, about 180 degrees) around the axis O1, and an arc portion 111 And extending portions 112 extending in the tangential direction from both circumferential ends.
The tube 102 is connected to a supply port (not shown) of the liquid tank 50Y, 50M, 50C, 50B (see FIG. 1) having one end (suction port 102a) disposed on the upstream side via a tube connector (not shown). It is connected. On the other hand, the other end (discharge port 102b) of the tube 102 is connected to a liquid supply pipe 51 (see FIG. 1) disposed on the downstream side via a tube connector (not shown). The tube 102 is arranged over the entire circumference of the housing 101 so that a part of the outer circumferential surface is in contact with the inner circumferential surface of the housing 101 in a state where the axial direction of the tube 102 is aligned with the circumferential direction of the inner circumferential surface of the housing 101. It has been searched. That is, the tube 102 is held in a substantially U shape within the housing 101.

  The rotator 104 is fixed to a motor shaft 105 of a drive motor (not shown) such as a DC motor inside the housing 101 in the radial direction. The rotating body 104 is configured to rotate around the axis O1 at a predetermined speed by driving of the drive motor (G1 in FIG. 2).

FIG. 3 is a sectional view of the oil damper.
Here, as shown in the figure, the rotating body 104 includes a pair of oil dampers (pressing force adjusting means) 121 that can expand and contract in accordance with a change in pressure in the tube 102. Each oil damper 121 is a so-called double cylinder type oil damper, and extends in the opposite direction from the axis O1 toward the inner peripheral surface of the housing 101 (outward in the radial direction). Specifically, the oil damper 121 is disposed between a cylinder 124 having an outer cylinder 122 and an inner cylinder 123 arranged coaxially, and the outer cylinder 122 and the inner cylinder 123, and communicates the outer cylinder 122 and the inner cylinder 123. A base valve 126 having a communication hole 125 formed therein, a piston 127 that partitions the inner cylinder 123 in the axial direction, and a piston rod 128 that is connected to the piston 127 and extends along the axial direction of the cylinder 124. I have. In addition, two types of fluids (oil (first fluid) P and gas (second fluid) Q) that do not mix with each other are sealed in the cylinder 124, and the inner cylinder 123 and the outer cylinder are communicated through the communication hole 125 of the base valve 126. The cylinder 122 is configured to be able to circulate. In addition, what is enclosed in the cylinder 124 is not limited to oil as long as it is a fluid.

The piston 127 has a through-hole 127a that penetrates in the axial direction of the inner cylinder 123, and is configured to be slidable in the inner cylinder 123 in the axial direction.
One end of the piston rod 128 is connected to the piston 127 in the cylinder 124 (inner cylinder 123). On the other hand, the other end side of the piston rod 128 protrudes outward of the cylinder 124. The roller 103 is rotatably supported at the other end of the piston rod 128 (see FIG. 2).

  Each roller 103 is a member arranged at an interval of 180 degrees around the other end of each piston rod 128, that is, around the axis O1. The axis O2 of each roller 103 is disposed in parallel to the axis O1. Each roller 103 is configured such that its outer peripheral surface is in contact with the opposite side of the tube 102 from the housing 101. That is, the tube 102 is sandwiched between the roller 103 and the arc portion 111 of the housing 101 and pressed from the radial direction R. The roller 103 is configured to revolve around the axis O1 (G1 in FIG. 2) and rotate around the axis O2 (G2 in FIG. 2) by the rotation of the rotating body 104. In the present embodiment, the radial direction R of the tube 102 is a direction that coincides with the normal direction of the peripheral wall of the housing 101 among the directions orthogonal to the axial direction of the tube 102.

  As described above, the pair of rollers 103 are disposed to face each other at a position different by 180 degrees around the axis O1. Thereby, the tube pump M of this embodiment can press the tube 102 in the direction where the roller 103 opposes. Therefore, the pair of rollers 103 can always press the tube 102 with a constant force around the axis O1. That is, the pressing direction of the roller 103 coincides with the radial direction R of the tube 102. Thereby, the tube pump M of this embodiment can maintain the stable liquid feeding state at the time of liquid feeding. Note that, as described above, the pair of rollers 103 is shown in the present embodiment, but the embodiment described below can also be implemented using a single roller 103.

(Function)
Next, the operation of the above-described tube pump will be described. FIG. 4 is a diagram for explaining the operation of the tube pump during normal operation, and FIG.
First, as shown in FIG. 4, the drive motor is driven to rotate the rotating body 104 around the axis O1. Then, the roller 103 attached to the rotating body 104 revolves around the axis O1. The roller 103 moves along the axial direction on the tube 102 while crushing the tube 102 along the radial direction with the arc portion 111 of the housing 101. As a result, the back side (traveling direction side) of the roller 103 in the tube 102 is pressurized, and the liquid in the tube 102 is sequentially pumped toward the downstream side. At this time, the roller 103 rotates around the axis O2 due to the frictional force with the outer peripheral surface of the tube 102, and thus moves smoothly on the tube 102.

Then, the liquid pumped through the tube 102 is discharged from the discharge port 102 b of the tube 102 into the liquid supply pipe 51 and is supplied to the liquid ejecting head 4 through the liquid supply pipe 51. Thereby, pressure filling to the liquid jet head 4 can be performed.
On the other hand, when the roller 103 revolves, the front side in the revolving direction of the roller 103 becomes negative pressure. Thereby, the liquid stored in the liquid container 50 is sucked into the tube 102 from the suction port 102 a of the tube 102. Thereby, the liquid accommodated in the liquid container 50 can be sequentially sucked by the tube pump M.

  Here, when the tube pump M is operated, the roller 103 always presses the tube 102 with a constant pressing force. Specifically, the pressing force F <b> 1 acts on the tube 102 from the roller 103 along the radial direction R. Furthermore, since the roller 103 moves on the tube 102 along the axial direction by the rotation of the rotating body 104, the rotational force F2 acts on the tube 102 from the roller 103 along the axial direction. Further, when the pressing force F1 acts on the tube 102, a repulsive force acts on the roller 103 from the tube 102 so as to resist the pressing force F1. This repulsive force varies depending on the pressure change in the tube 102.

  By the way, as mentioned above, when clogging or the like occurs in the tube 102, there is a problem that the pressure in the tube 102 increases rapidly.

6 and 7 are explanatory diagrams of the operation of the tube pump, FIG. 6 is a plan view of the tube pump, and FIG. 7 is a cross-sectional view of the oil damper.
As shown in FIGS. 5 to 7, when the pressure in the tube 102 rises rapidly, the repulsive force acting on the roller 103 from the tube 102 increases in accordance with this pressure change. Then, the piston rod 128 of the oil damper 121 moves in the cylinder 124 (inner cylinder 123) in a contracted manner. As a result, the roller 103 is displaced in the radial direction of the tube 102 (a direction away from the tube 102). Therefore, when the space between the roller 103 and the housing 101 is expanded, the cross-sectional area of the tube 102 is increased, and the pressure in the tube 102 can be relieved. Therefore, the pressure in the tube 102 can be maintained almost constant.

As described above, in this embodiment, the oil damper 121 that allows the roller 103 to move in a direction away from the tube 102 according to the force acting on the roller 103 from the tube 102 is provided.
According to this configuration, when the pressure in the tube 102 increases, the piston rod 128 of the oil damper 121 is displaced in a direction away from the tube 102 by being pushed by the tube 102, so that the space between the roller 103 and the housing 101 is increased. The pressure in the tube 102 can be relaxed by enlarging. Thereby, it is possible to take an explosion-proof measure without providing sensors for detecting the pressure or flow rate in the tube 102 or providing a flow rate control valve or the like. Therefore, the cost increase of the tube pump M can be suppressed, and the configuration can be simplified. Further, since it is not necessary to control the rotation of the drive motor as an explosion-proof measure, a relatively inexpensive drive motor can be employed. Also by this, the cost increase of the tube pump M can be suppressed.

  In addition, in this embodiment, the pressing force F <b> 1 by the roller 103 can be changed by changing the pressure in the oil damper 121. Thereby, since the manufacturing variation of the tube 102, the roller 103, etc. can be absorbed, the variation of the suction pressure and discharge pressure of the tube pump M at the time of normal use can be reduced.

Further, by changing the pressing force F1 by the roller 103, the same oil damper 121 can be used for various tubes 102 having different tube diameters and wall thicknesses. That is, since the oil damper 121 can be shared, the cost can be reduced and the manufacturing efficiency can be improved as compared with the case where the oil damper 121 suitable for each tube 102 is manufactured separately.
Further, in the present embodiment, a sufficient stroke amount can be secured even with a small component such as the tube pump M by employing the double cylinder type oil damper 121 as the pressing force adjusting means.

By the way, when the tube pump M is not used, when the rotation of the tube pump M is stopped, the roller 103 continues to press one portion of the tube 102. As a result, the tube 102 may be deteriorated.
Therefore, in this embodiment, the pressure of the oil damper 121 is adjusted to separate the roller 103 from the tube 102, so that the pressing of the tube 102 by the roller 103 is released. Thereby, it can prevent that the tube 102 always receives the pressing force F1 by the roller 103. FIG. Therefore, the progress of deterioration of the tube 102 can be suppressed, and the life of the tube pump M can be extended.

  Since the liquid jet recording apparatus 1 of the present embodiment includes the tube pump M described above, the cost can be reduced and the apparatus can be simplified, and the reliability can be improved and the life can be extended. be able to.

  In the first embodiment described above, the case where the double cylinder type oil damper 121 is used as the pressing force adjusting means has been described. However, the present invention is not limited to this, and a so-called single cylinder type oil damper 130 may be used. Specifically, as shown in FIG. 8, the oil damper 130 divides the cylinder 131 and the cylinder 131 into a first chamber 131 a and a second chamber 131 b along the axial direction, and the inside of the cylinder 131 in the axial direction. A free piston 132 slidable along the axial direction, a through-hole 133 a penetrating in the axial direction, and a piston 133 slidable in the axial direction in the first chamber 131 a, and coupled to the piston 133. The piston rod 134 extends along the axial direction of the cylinder 131. Oil P is sealed in the first chamber 131a, and gas Q is sealed in the second chamber 131b.

According to this configuration, similarly to the above-described double cylinder type oil damper 121, as shown in FIG. 9, the piston rod 134 moves in the cylinder 131 in accordance with the repulsive force acting on the roller 103 from the tube 102. To do. Thereby, there can exist the same effect as a 1st embodiment mentioned above.
Further, the structure can be simplified as compared with the above-described double cylinder type oil damper 121, and the low cost tube pump M can be provided.

When the pressure increase in the tube 102 is eliminated, the roller 103 returns to a state in which the tube 102 is crushed (normal state) as shown in FIGS. In FIG.7 and FIG.9 mentioned above, the enclosed gas Q showed the form compressed. This is because the piston rods 128 and 134 are displaced in the radial direction of the tube 102 (the direction away from the tube 102) by the repulsive force of the tube 102, and the pistons 127 and 133 press the oil P.
When the pressure increase in the tube 102 is eliminated and the repulsive force is weakened, a restoring force is applied to return the compressed gas Q to the normal state. Due to this restoring force, the pistons 127 and 133, the piston rods 128 and 134, and the roller 103 are displaced in the direction opposite to the direction displaced by the repulsive force of the tube 102. As a result, when the pressure increase in the tube 102 is eliminated, the roller 103 returns to a state in which the tube 102 is crushed.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 10 is a plan view of the tube pump in the second embodiment. The present embodiment is different from the first embodiment described above in that a cam mechanism is employed as the pressing force adjusting means. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
As shown in FIG. 10, the pressing force adjusting means 151 of the present embodiment includes a casing 161 fixed to a motor shaft (rotating shaft) 105, a cam member 152 rotatably accommodated in the casing 161, and a cam member. A pair of sliding members (first sliding member 153a and second sliding member 153b) that move in the radial direction of the tube 102 while slidingly contacting the peripheral surface of the cam member 152 as the 152 rotates, and a casing 161 and a pair of urging means 154 disposed between the cam member 152 and the cam member 152.

The casing 161 is formed in a rectangular parallelepiped shape, and the motor shaft 105 is fixed to the center portion of the rear wall portion 159 (the rear wall portion in FIG. 10). The casing 161 is configured to rotate around the axis O1 by driving of a drive motor. In the casing 161, a rotating shaft 158 extending coaxially with the motor shaft 105 (axis line O1) is provided. A cam member 152 is rotatably supported on the rotation shaft 158.
The cam member 152 is an elliptical plate member having an outer peripheral surface constituted by a pair of curved surfaces 155, and the above-described rotating shaft 158 is attached to the center of the cam member 152 (intersection of the major axis and the minor axis). .

  The pair of sliding members 153 a and 153 b are inserted through the collars 157 from the positions offset in the surface direction in the opposing side wall portions 156 in the casing 161. Specifically, one end of the first sliding member 153 a is in contact with one end in the circumferential direction of one curved surface 155 of the cam member 152 in the casing 161. Further, the other end side of the first sliding member 153 a extends outward from the side wall portion 156 of the housing 101. The other end of the first sliding member 153a rotatably supports one roller 103. Further, one end of the second sliding member 153 b is in contact with one end in the circumferential direction of the other curved surface 155 of the cam member 152 in the casing 161. Furthermore, the other end side of the second sliding member 153 b extends outward from the side wall portion 156 of the housing 101. The other end of the second sliding member 153b rotatably supports the other roller 103.

  Each urging means 154 includes a coil spring or the like, and is connected to the opposite side wall portion 163 and the cam member 152 in the casing 161. Specifically, one urging means 154 has one end connected to one side wall 163. Further, the one biasing means 154 is in contact with the other end in the circumferential direction of the one curved surface 155 of the cam member 152 via the contact member 162. The other urging means 154 has one end connected to the other side wall 163. Further, the other biasing means 154 is in contact with the other end in the circumferential direction of the other curved surface 155 of the cam member 152 via the contact member 162. That is, the urging means 154 is configured to urge the cam member 152 in the direction opposite to the rotation direction G1. The contact member 162 is configured to be slidable on the peripheral surface of the cam member 152 as the cam member 152 rotates.

Next, the operation of the tube pump of the second embodiment will be described.
The drive motor is driven to rotate the casing 161 around the axis O1. Then, the pressing force adjusting means 151 and the roller 103 are integrally rotated around the axis O1 (see arrow G1 in FIG. 10). That is, the rotary shaft 158 or the motor shaft 105 and the casing 161 are fixed, and the entire pressing force adjusting means 151 rotates when the drive motor is driven. The first sliding member 153a and the second sliding member 153b are slidably supported by the collar 157, and the first sliding member 153a and the second sliding member 153b are accompanied with the rotation of the casing 161. Rotate each. At this time, a repulsive force acting on the roller 103 from the tube 102 acts on the cam member 152 in the same direction as the rotational direction G1 via the sliding members 153a and 153b. That is, the repulsive force acts so that the roller 103 is displaced in the radial direction of the tube 102 (the direction away from the tube 102). In accordance with this repulsive force, a displacement force for displacing the first sliding member 153a and the second sliding member 153b in a direction away from the tube 102 acts. Due to this displacement force, the first sliding member 153a and the second sliding member 153b respectively positioned at the tip of the curved surface 155 attempt to rotate the cam member 152 in the rotational direction G1 following the curved surface 155.

On the other hand, the urging force by the urging means 154 acts on the cam member 152 against the rotation direction G1. That is, the rotational force for rotating the cam member 152 in the rotational direction G1 and the urging force by the urging means 154 are balanced. Note that the rotational force for rotating the cam member 152 in the rotation direction G1 in a state where the roller 103 can rotate while pressing the tube 102 is known by measuring in advance. The urging force by the urging means 154 is designed as the same value as this rotational force.
Therefore, the roller 103 can always rotate while pressing the tube 102 with a constant pressing force.

FIG. 11 is an explanatory view of the operation of the tube pump.
Here, when the pressure in the tube 102 rises rapidly, the repulsive force that acts on the roller 103 from the tube 102 in accordance with this pressure change increases, and the force that rotates the cam member 152 in the rotational direction G1 increases. Then, as shown in FIG. 11, the urging means 154 is compressed via the cam member 152, and the cam member 152 rotates about the axis O1. As a result, the sliding members 153 a and 153 b are retracted into the casing 161 while sliding on the curved surfaces 155 of the cam member 152. Therefore, the roller 103 moves in the radial direction of the tube 102 (direction away from the tube 102). Therefore, the space between the roller 103 and the housing 101 can be expanded to relieve the pressure in the tube 102. Therefore, the pressure in the tube 102 can be maintained almost constant. That is, the spring constant of the coil spring does not compress and deform when the pressure in the tube 102 is within a desired value, and is strong enough to gradually compress and deform when the pressure in the tube 102 exceeds the desired value. Is set to

Thus, also in the present embodiment, the same effects as those of the first embodiment described above can be achieved.
In the present embodiment, the distance between the roller 103 and the inner peripheral surface of the housing 101 can be changed by changing the allowable rotation angle of the cam member 152 in the pressing force adjusting means 151. Thereby, the pressing force F1 by the roller 103 can be changed.

Further, in the present embodiment, by adjusting the rotation allowable angle of the cam member 152 and separating the roller 103 from the tube 102, the pressing of the tube 102 by the roller 103 is released. In this case, it is also possible to provide a stopper 170 in front of the cam member 152 in the rotation direction (see FIG. 10) and set the rotation allowable angle of the cam member 152 step by step.
Thereby, since it can prevent that the tube 102 always receives the pressing force F1 by the roller 103, the progress of deterioration of the tube 102 can be suppressed. Therefore, the lifetime of the tube pump M can be extended.

When the pressure increase in the tube 102 is eliminated, the roller 103 returns to a form (normal state) in which the tube 102 is crushed as shown in FIG. In FIG. 11 described above, the cam member 152 is rotated due to the balance between the rotational force of the cam member 152 and the biasing force of the biasing means 154 being broken. This is because the first sliding member 153a and the second sliding member 153b are displaced in the radial direction of the tube 102 (a direction away from the tube 102) by the repulsive force of the tube 102, and the cam member 152 is rotated in the rotation direction G1. This is because the power to do was increased.
When the pressure increase in the tube 102 is eliminated and the repulsive force is weakened, the urging force of the urging means 154 acts as a restoring force for returning the cam member 152 to the normal state shown in FIG. By this restoring force, the first sliding member 153a, the second sliding member 153b, and the roller 103 are displaced in the direction opposite to the direction displaced by the repulsive force of the tube 102. As described above, when the pressure increase in the tube 102 is eliminated, the roller 103 returns to a form in which the tube 102 is crushed. Since the balance between the rotational force of the cam member 152 and the biasing force of the biasing means 154 is maintained, the first sliding member 153a and the second sliding member 153b are stationary at the positions shown in FIG. The pressure adjusting means 151 rotates while crushing the tube 102 by the rotation of the motor.

(Third embodiment)
Next, a third embodiment of the present invention will be described. The third embodiment is different from the above-described embodiment in that the pressing force adjusting means is constituted by an urging means such as a coil spring. FIG. 12 is a plan view of the tube pump in the third embodiment.
As shown in the figure, the pressing force adjusting means 201 of the present embodiment includes a pair of spring members 202 extending in opposite directions from the motor shaft 105 toward the inner peripheral surface of the housing 101, and the spring members 202. A bearing member 203 that is coupled to the tip and rotatably supports the roller 103, and an adjustment mechanism 204 that adjusts the urging force of each spring member 202 are provided.

  Each spring member 202 is connected to a support member 210 attached to the motor shaft 105 on the base end side. On the other hand, the tip side of each spring member 202 is connected to the bearing member 203. Accordingly, the roller 103 is configured to be movable in a direction approaching and separating from the tube 102 in accordance with a pressure change in the tube 102 due to elastic deformation of the spring member 202.

  The adjusting mechanism 204 includes a pair of arms 212 respectively connected to the bearing members 203. Each arm 212 is configured to be bent in a crank shape, and one end side thereof is connected to each bearing member 203. On the other hand, the other end sides of the arms 212 are arranged to face each other. Further, a through hole (not shown) that penetrates in the thickness direction of the arm 212 is formed on the other end side of the arm 212. Each arm 212 is fastened to the other end side by a bolt 213 and a nut 214. Specifically, a bolt 213 is inserted into each through hole of the arm 212 from the one arm 212 side toward the other arm 212 side, and a nut 214 is inserted from the other arm 212 side.

  According to this configuration, the spring member 202 is elastically deformed in accordance with the pressure change in the tube 102, so that the arm 212 moves toward the approaching / separating direction. As a result, the roller 103 moves in a direction away from the tube 102. Therefore, the space between the roller 103 and the housing 101 is expanded, and the pressure in the tube 102 can be relieved.

When the pressure increase in the tube 102 is eliminated, the roller 103 returns to a form in which the tube 102 is crushed as shown in FIG. In the embodiment described above, the urging force of the spring member 202 is set to a value that the roller 103 rotates while pressing the tube 102. When the pressure inside the tube 102 rises, the spring member 202 contracts toward the motor shaft 105 (inward in the radial direction of the housing 101) due to the repulsive force of the tube 102.
When the pressure increase in the tube 102 is eliminated and the repulsive force is weakened, the biasing force of the spring member 202 acts as a restoring force for returning the roller 103 to the normal state shown in FIG. Due to this restoring force, the roller 103 is displaced in the direction opposite to the direction displaced by the repulsive force of the tube 102 (outside in the radial direction of the housing 101). As a result, when the pressure increase in the tube 102 is eliminated, the roller 103 returns to a state in which the tube 102 is crushed.

Further, in the present embodiment, the arms 212 move in the approaching and separating directions according to the distance between the bolt 213 and the nut 214, and the spring member 202 expands and contracts. For this reason, the space | interval of the housing 101 and the roller 103 can be adjusted. To adjust this interval, the pressing force F1 of the tube 102 by the roller 103 is adjusted.
Further, by adjusting the pressing force F1 of the tube 102 by the roller 103 by adjusting the distance between the housing 101 and the roller 103, the pressing force F1 acting on the tube 102 from the roller 103 can be reduced without changing the spring member 202 itself. Can be changed.

  Moreover, by adjusting the distance between the bolt 213 and the nut 214 to separate the roller 103 from the tube 102, the pressing of the tube 102 by the roller 103 is released. Thereby, it can prevent that the tube 102 always receives the pressing force F1 by the roller 103. FIG. Therefore, the progress of deterioration of the tube 102 can be suppressed, and the life of the tube pump M can be extended.

In the third embodiment described above, the configuration in which the spring member 202 is compressed by the adjustment mechanism 204 and the roller 103 is separated from the tube 102 has been described. However, the present invention is not limited to this, and as shown in FIG. 13, the pressing release member 220 may be provided separately.
Specifically, the pressing release member 220 is a C-shaped member, and a restricting portion 222 that is orthogonal to the extending direction of the arm portion 221 is formed at both ends of the arm portion 221. And the roller 103 can be hold | maintained in the state spaced apart from the tube 102 by pinching the bearing members 203 by each control part 222 in the state which compressed the spring member 202. FIG.

As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
For example, in the above-described embodiment, the configuration in which the tube 102 is routed in an arc along the housing 101 has been described. However, if the roller 103 moves while crushing the tube with the housing 101, Design changes can be made as appropriate. For example, the tube 102 may be routed in a straight line.

Furthermore, although the embodiment mentioned above demonstrated the structure pressurized and filled using the tube pump M, it is not restricted to this. That is, a suction cap may be provided at a position facing the ejection surface of the liquid ejecting head 4 and the tube pump M may be used when sucking the inside of the suction cap.
The pressing force adjusting means can be appropriately changed in design as long as it is configured to approach and separate from the tube 102 in accordance with the force acting on the roller 103 from the tube 102. For example, the roller 103 may be supported by the tip of a retractable arm, and the roller 103 may be urged toward the tube 102 via an elastic member. Even in this case, since the roller 103 is displaced according to the pressure in the tube 102, the same effect as that of the above-described embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Liquid jet recording apparatus 4 ... Liquid jet head 50 ... Liquid container 51 ... Liquid supply pipe 102 ... Tube 103 ... Roller (pressing means) 105 ... Motor shaft (rotating shaft) 121 ... Oil damper (pressing force adjusting means) 124 131, 201 ... Cylinder 151, 201 ... Pressure adjusting means 127, 133 ... Piston 128, 134 ... Piston rod 152 ... Cam member 153 ... Sliding member 202 ... Spring member 204 ... Adjustment mechanism M ... Tube pump P ... Oil (first) Fluid) Q ... Gas (second fluid)

Claims (6)

A flexible tube;
Pressing means for moving along the axial direction of the tube while pressing the tube from the outside;
In the tube pump that pumps the fluid in the tube by moving the pressing means while crushing the tube,
The pressing means is provided with a pressing force adjusting means capable of displacing the pressing means in a direction approaching and separating from the tube in accordance with a force acting on the pressing means from the tube. And tube pump. The pressing force adjusting means includes a cylinder in which a first fluid and a second fluid that cannot be mixed are sealed, a piston movable in the cylinder, and one end side connected to the piston while the other end side is from the cylinder. A piston rod that protrudes and supports the pressing means,
The tube pump according to claim 1, wherein the piston rod is configured to be able to advance and retreat in the cylinder in a direction approaching and separating from the tube.   The tube pump according to claim 2, wherein the cylinder includes an inner cylinder in which the piston moves and an outer cylinder coaxial with the inner cylinder and disposed on the outside. The pressing force adjusting means includes a cam member attached to the rotating shaft, and a sliding member whose one end side slides on the circumferential surface of the cam member and whose other end side supports the pressing means,
2. The tube pump according to claim 1, wherein the sliding member is configured to be displaceable in a direction in which the sliding member approaches and separates from the tube as the cam member rotates.   The pressing force adjusting means includes a spring member that urges the pressing means toward the tube, and an adjustment mechanism that adjusts the urging force of the spring member by adjusting a spring length of the spring member. The tube pump according to claim 1. A liquid container that contains liquid;
A liquid ejecting head for ejecting the liquid;
The tube pump according to any one of claims 1 to 5, wherein the liquid in the liquid container is pressure-fed toward the liquid ejecting head through a liquid supply pipe. Liquid jet recording apparatus.

Images