JP6973973B2 - Liquid pump - Google Patents

Description

The present invention relates to a liquid pump that sucks in and discharges a liquid.

Conventionally, there is a liquid pump that sucks and discharges a liquid by reciprocating the diaphragm by the rotation of a variable speed motor (see Patent Document 1). In the liquid pump described in Patent Document 1, it is stated that the discharge amount of the liquid can be controlled from a small amount to a large amount by adjusting the rotation speed of the variable speed motor.

Japanese Unexamined Patent Publication No. 11-1553224

By the way, when bubbles are present in the liquid, the discharge amount of the liquid cannot be accurately controlled. Further, in the liquid pump that reciprocates the diaphragm, pulsation occurs in the flow of the liquid, which may reduce the controllability of the discharge amount. Therefore, the liquid pump described in Patent Document 1 still has room for improvement. It is conceivable to measure and control the discharge amount of the liquid with a flow meter, but it is inevitable that the size and cost of the device will increase.

The present invention has been made to solve the above problems, and to provide a liquid pump capable of accurately controlling the discharge amount of a liquid and reducing the size even when a flow meter is not used. Is the main purpose.

The first means for solving the above-mentioned problem is a liquid pump.
The first suction flow path and
The first pressure chamber connected to the first suction flow path and
The first discharge flow path connected to the first pressure chamber and
The second suction flow path and
A second pressure chamber connected to the second suction flow path and
The second discharge flow path connected to the second pressure chamber and
A suction side connection flow path that is connected to the inflow port into which the liquid flows and connects the first suction flow path and the second suction flow path,
A discharge side connection flow path that connects the first discharge flow path and the second discharge flow path and is connected to the outlet from which the liquid flows out.
With the motor
A drive mechanism that alternately reduces the first pressure chamber and the second pressure chamber, and expands the first pressure chamber and reduces the second pressure chamber based on the rotation of the motor.
A bubble sensor attached to at least one of the suction side connection flow path and the discharge side connection flow path and detecting bubbles contained in the liquid flowing in the attached flow path, and a bubble sensor.
A control unit that adjusts the rotation speed of the motor to control the discharge amount of the liquid on condition that the bubble is not detected by the bubble sensor.
To prepare for.

According to the above configuration, the suction side connection flow path is connected to the inflow port where the liquid flows in, and connects the first suction flow path and the second suction flow path. Further, the discharge side connection flow path connects the first discharge flow path and the second discharge flow path, and is connected to the outlet where the liquid flows out. Then, the drive mechanism alternately reduces the first pressure chamber and the second pressure chamber, and expands the first pressure chamber and reduces the second pressure chamber based on the rotation of the motor. Therefore, the liquid can be alternately discharged from the first pressure chamber and the second pressure chamber, and the pulsation of the liquid can be suppressed as compared with the case where the liquid is discharged from only one pressure chamber. That is, the pulsation of the liquid can be suppressed by intentionally discharging the same liquid instead of discharging different liquids from the two pressure chambers.

Further, since the liquid can be circulated from the inflow port to the first suction flow path and the second suction flow path by the suction side connection flow path, the space for arranging the suction side flow path can be reduced. Similarly, since the liquid can be circulated from the first discharge flow path and the second discharge flow path to the outlet by the discharge side connection flow path, the space for arranging the discharge side flow path can be reduced. Moreover, the first pressure chamber and the second pressure chamber are reduced and expanded by the common drive mechanism. Therefore, the liquid pump can be miniaturized.

Here, the bubble sensor is attached to at least one of the suction side connection flow path and the discharge side connection flow path, and detects bubbles contained in the liquid flowing in the attached flow path. Then, the control unit adjusts the rotation speed of the motor to control the discharge amount of the liquid on condition that the bubble is not detected by the bubble sensor. Therefore, it is possible to accurately control the discharge amount of the liquid by adjusting the rotation speed of the motor in a state where the liquid does not contain air bubbles. Therefore, even when the flow meter is not used, the discharge amount of the liquid can be accurately controlled. On the other hand, when the liquid contains air bubbles, the discharge amount of the liquid is not controlled by adjusting the rotation speed of the motor, so that it is possible to prevent the discharge amount of the liquid from becoming inaccurate.

The bubbles contained in the liquid flowing through the suction side connection flow path are alternately sucked into the first pressure chamber and the second pressure chamber and discharged. Therefore, basically, bubbles contained in the liquid can be detected by a bubble sensor attached to at least one of the suction side connection flow path and the discharge side connection flow path.

In the second means, at least one of the suction side connection flow path and the discharge side connection flow path includes a tube portion formed of a transparent resin tube, and the bubble sensor is an optical bubble sensor. It is attached to the tube portion, and the tube portion is housed in a housing that blocks ultraviolet rays.

According to the above configuration, at least one of the suction side connection flow path and the discharge side connection flow path includes a tube portion formed of a transparent resin tube. The optical bubble sensor is attached to a transparent tube portion. Therefore, the bubble sensor can detect bubbles based on the light transmitted through the transparent tube portion. According to the transparent resin tube, the light transmitting portion required for the optical bubble sensor can be easily formed.

However, generally transparent resin tubes have the property of whitening when exposed to ultraviolet rays for a long period of time. In that case, the accuracy of bubble detection by the bubble sensor may decrease. In this respect, since the tube portion is housed in a housing that blocks ultraviolet rays, it is possible to prevent the tube portion from whitening. Further, the optical bubble sensor can be made smaller than the microwave type bubble sensor, the ultrasonic type bubble sensor, or the like.

If the tube portion formed of the transparent resin tube is flexible, the tube portion may bend and hang down. In that case, there is a possibility that the attachment of the tube portion may be hindered or the liquid may easily leak from the connection portion of the tube portion.

In this respect, in the third means, in the tube portion, a metal tube is fitted on the outer periphery of a portion other than the portion to which the bubble sensor is attached. Therefore, the tube portion can be supported by the metal tube, and the tube portion can be prevented from hanging down. Further, by fixing the metal tube, the tube portion can be easily fixed. Therefore, the tube portion can be easily attached, and the liquid can be prevented from easily leaking from the connection portion of the tube portion.

In the fourth means, the suction side connection flow path and the discharge side connection flow path include the tube portion, respectively, and the bubble sensor is connected to the inflow port in the tube portion of the suction side connection flow path. A first bubble sensor attached between the second suction flow path and a second bubble attached between the first discharge flow path and the outlet in the tube portion of the discharge side connection flow path. Includes sensors.

According to the above configuration, the bubble sensor is the first bubble sensor attached between the inflow port and the second suction flow path in the tube portion of the suction side connection flow path, and the first bubble sensor in the tube portion of the discharge side connection flow path. 1 Includes a second bubble sensor mounted between the discharge channel and the outlet. Therefore, the bubbles contained in the liquid that sequentially flows from the inlet to the suction side connection flow path, the second suction flow path, the second pressure chamber, the second discharge flow path, the discharge side connection flow path, and the outlet are first. It can be detected by the bubble sensor. On the other hand, the bubbles contained in the liquid that sequentially flows from the inlet to the suction side connection flow path, the first suction flow path, the first pressure chamber, the first discharge flow path, the discharge side connection flow path, and the outlet are the second bubbles. It can be detected by a sensor. Therefore, even when the air bubbles flow in only one of the first suction flow path and the second suction flow path, the air bubbles can be detected without leakage.

In the fifth means, the drive mechanism reciprocates a first reciprocating member that reciprocates so as to reduce and expand the first pressure chamber, and a second reciprocating member that reciprocates so as to expand and contract the second pressure chamber. A reciprocating member, a connecting member for connecting the first reciprocating member and the second reciprocating member, and connecting the first pressure chamber and the second pressure chamber based on the rotation of the motor. The connecting member is reciprocated in the direction, and the longitudinal direction of the portion connecting the first suction flow path and the second suction flow path in the suction side connection flow path, and the first in the discharge side connection flow path. The longitudinal direction of the portion connecting the one discharge flow path and the second discharge flow path is parallel to the reciprocating direction of the connecting member.

According to the above configuration, the first reciprocating member that reciprocates so as to reduce and expand the first pressure chamber and the second reciprocating member that reciprocates so as to expand and contract the second pressure chamber are connected. It is connected by a member. Then, based on the rotation of the motor, the connecting member is reciprocated in the direction connecting the first pressure chamber and the second pressure chamber. Therefore, based on the rotation of the motor, the first reciprocating member reduces the first pressure chamber, and the second reciprocating member expands the second pressure chamber. Further, based on the rotation of the motor, the first reciprocating member expands the first pressure chamber, and the second reciprocating member reduces the second pressure chamber. Therefore, the liquid can be alternately discharged from the first pressure chamber and the second pressure chamber.

Further, in the suction side connection flow path, the longitudinal direction of the portion connecting the first suction flow path and the second suction flow path, and in the discharge side connection flow path, the first discharge flow path and the second discharge flow path are connected. The longitudinal direction of the portion is parallel to the longitudinal direction of the connecting member. Therefore, the suction side connection flow path, the discharge side connection flow path, and the bubble sensor can be arranged on the side of the space where the connecting member reciprocates. Therefore, the connecting member, the suction side connection flow path, the discharge side connection flow path, and the bubble sensor can be efficiently arranged, and the liquid pump can be miniaturized.

In the sixth means, the connecting member includes a plate-shaped portion formed in a rectangular plate shape, and the first sliding member is attached to each diagonal of the first main surface of the plate-shaped portion. The second sliding member is attached diagonally to the second main surface of the plate-shaped portion so as not to overlap with the first sliding member, and the first sliding member faces the first main surface. The second sliding member slides on the first sliding member arranged in parallel with the plate-shaped portion, and the second sliding member is arranged in parallel with the plate-shaped portion facing the second main surface. It slides with the sliding member.

According to the above configuration, the connecting member includes a plate-shaped portion formed in a rectangular plate shape, and the first sliding member is attached diagonally to the first main surface of the plate-shaped portion, respectively, and the plate-shaped portion is attached. The second sliding member is attached diagonally to the second main surface of the above so as not to overlap with the first sliding member. That is, in the plate-shaped portion, the diagonal to which the first sliding member is attached is different from the diagonal to which the second sliding member is attached. Therefore, the first sliding member and the second sliding member do not overlap each other via the plate-shaped portion, and the mounting member (for example, a screw) for mounting the first sliding member and the mounting for mounting the second sliding member are mounted. It is possible to prevent the member from interfering with the member. Therefore, the structure in which the plate-shaped portion, the first sliding member, and the second sliding member are assembled can be thinned, and the liquid pump can be miniaturized. The first main surface and the second main surface are the two largest surfaces of the rectangular plate-shaped plate-shaped portion, and the second main surface is the back surface of the first main surface.

Then, the first sliding member slides on the first sliding member arranged in parallel with the plate-shaped portion facing the first main surface, and the second sliding member faces the second main surface. Then, it slides on the second sliding member arranged in parallel with the plate-shaped portion. Therefore, the first sliding member is attached to two of the four corners of the first main surface, and the second sliding member is attached to two of the four corners of the second main surface. Even so, it is possible to suppress the rotation of the connecting member around the center line of the connecting member.

In the seventh means, the first suction flow path, the first discharge flow path, the second suction flow path, the second discharge flow path, the suction side connection flow path, and the discharge side connection flow path are They are arranged along a common plane. Therefore, the flow path of the liquid pump can be efficiently arranged along a common plane, and the liquid pump can be made thinner.

Eighth means comprises a three-way switching valve having a valve inlet, a first valve outlet, and a second valve outlet, the valve inlet being directly connected to the outlet, and the first valve outlet being the first valve outlet. The outlet for discharging the liquid, and the outlet for the second valve is an outlet for discharging bubbles contained in the liquid, and is open upward.

According to the above configuration, the valve inlet of the three-way switching valve is directly connected to the outlet from which the liquid flows out. Therefore, a pipe connecting the outlet and the valve inlet is not required, and the liquid pump can be miniaturized. Since the first valve outlet is an outlet for discharging the liquid, the liquid can be discharged from the first valve outlet by connecting the valve inlet and the first valve outlet with a three-way switching valve. Further, the second valve outlet is an outlet for discharging air bubbles contained in the liquid, and is open upward. Therefore, by connecting the valve inlet and the second valve outlet with a three-way switching valve, air bubbles can be easily discharged from the second valve outlet that opens upward.

In the ninth means, when the bubble is detected by the bubble sensor, the control unit connects the valve inlet and the second valve outlet by the three-way switching valve, and the bubble sensor connects the valve inlet and the second valve outlet. Is determined to be abnormal when the period in which is detected exceeds a predetermined period.

According to the above configuration, the control unit connects the valve inlet and the second valve outlet by the three-way switching valve when the bubble is detected by the bubble sensor. Therefore, when the liquid temporarily contains air bubbles, the air bubbles can be discharged. Further, the control unit determines that the abnormality is obtained when the period in which the bubble is detected by the bubble sensor exceeds a predetermined period. Therefore, if the end of the pipe or the like connected to the inflow port of the liquid is above the liquid level of the liquid tank, or if it is not possible to prevent the mixing of air bubbles, it can be determined to be abnormal.

The tenth means is a liquid pump,
The suction flow path connected to the inflow port where the liquid flows in,
A pressure chamber connected to the suction flow path and
A discharge flow path connecting the pressure chamber and the outlet from which the liquid flows out,
With the motor
A drive mechanism that alternately reduces and expands the pressure chamber based on the rotation of the motor.
A bubble sensor attached to at least one of the suction flow path and the discharge flow path and detecting bubbles contained in the liquid flowing in the attached flow path, and a bubble sensor.
A control unit that adjusts the rotation speed of the motor to control the discharge amount of the liquid on condition that the bubble is not detected by the bubble sensor.
Equipped with
At least one of the suction flow path and the discharge flow path includes a tube portion formed of a transparent resin tube.
The bubble sensor is an optical bubble sensor, which is attached to the tube portion.
The tube portion is housed in a housing that blocks ultraviolet rays.

According to the above configuration, the suction flow path is connected to the inlet where the liquid flows in and is connected to the pressure chamber. Further, the discharge flow path connects the pressure chamber and the outlet from which the liquid flows out. Then, the drive mechanism alternately reduces and expands the pressure chamber based on the rotation of the motor. Therefore, the liquid can be sucked into the pressure chamber and the liquid can be discharged from the pressure chamber.

Here, a bubble sensor is attached to at least one of the suction flow path and the discharge flow path, and detects bubbles contained in the liquid flowing in the attached flow path. Then, the control unit adjusts the rotation speed of the motor to control the discharge amount of the liquid on condition that the bubble is not detected by the bubble sensor. Therefore, it is possible to accurately control the discharge amount of the liquid by adjusting the rotation speed of the motor in a state where the liquid does not contain air bubbles. Therefore, even when the flow meter is not used, the discharge amount of the liquid can be accurately controlled. On the other hand, when the liquid contains air bubbles, the discharge amount of the liquid is not controlled by adjusting the rotation speed of the motor, so that it is possible to prevent the discharge amount of the liquid from becoming inaccurate.

Further, at least one of the suction flow path and the discharge flow path includes a tube portion formed of a transparent resin tube. The optical bubble sensor is attached to a transparent tube portion. Therefore, the bubble sensor can detect bubbles based on the light transmitted through the transparent tube portion. According to the transparent resin tube, the light transmitting portion required for the optical bubble sensor can be easily formed.

However, generally transparent resin tubes have the property of whitening when exposed to ultraviolet rays for a long period of time. In that case, the accuracy of bubble detection by the bubble sensor may decrease. In this respect, since the tube portion is housed in a housing that blocks ultraviolet rays, it is possible to prevent the tube portion from whitening. Further, the optical bubble sensor can be made smaller than the microwave type bubble sensor, the ultrasonic type bubble sensor, or the like.

In the eleventh means, in the tube portion, a metal tube is fitted on the outer periphery of a portion other than the portion to which the bubble sensor is attached.

According to the above configuration, the same effect as that of the third means can be obtained.

Perspective view of the liquid pump. Partial perspective perspective of the liquid pump. A vertical sectional view showing a crank mechanism. A vertical cross-sectional view showing a flow path, a pressure chamber, and a connecting member.

Hereinafter, an embodiment embodied in a liquid pump used in a liquid fertilizer supply system will be described with reference to the drawings. As shown in FIGS. 1 and 2, the liquid pump 10 includes a motor unit 20, a pump unit 30, and a control unit 90. The control unit 90 is a microcomputer including a CPU, a ROM, a RAM, a drive circuit, an input / output interface, and the like. The liquid pump 10 controls the drive state of the motor unit 20 by the control unit 90, so that the pump unit 30 sucks and discharges liquid fertilizer (liquid).

The motor unit 20 includes a motor, a speed reducer that reduces the rotational speed of the motor, and the like. The rotation speed (driving state) of the motor is controlled by the control unit 90. As shown in the vertical sectional view of FIG. 3, the output shaft 21 of the motor unit 20 is inserted inside the pump unit 30. The pump unit 30 includes a crank mechanism 40. The crank shaft 41 of the crank mechanism 40 is connected to the output shaft 21. The center line of the output shaft 21 and the center line of the crank shaft 41 coincide with each other. The crank shaft 41 is rotatably supported by the main body 31 of the pump portion 30 via the bearing 22. The main body 31 is formed of a metal or the like that blocks ultraviolet rays. The main body 31 is formed in a rectangular parallelepiped shape (box shape), and a space is formed inside the main body 31.

A crank pin 42 is connected to the crank shaft 41. The crank pin 42 is connected to the crank shaft 41 at a position eccentric from the center line of the output shaft 21 (crank shaft 41). Therefore, when the output shaft 21 rotates, the crank pin 42 revolves around the output shaft 21.

A roller 45 is attached to the outer periphery of the crankpin 42 by a bolt 43 via a bearing 44. That is, the roller 45 is rotatably supported by the crankpin 42 via the bearing 44.

As shown in the vertical cross-sectional view of FIG. 4, a first flow path block 50 and a second flow path block 60 are attached to both ends of the main body 31 in the longitudinal direction (left-right direction in the figure), respectively. The first and second flow path blocks 50 and 60 are formed in substantially the same shape by a resin or the like that blocks ultraviolet rays.

The first flow path block 50 is formed with a first suction flow path 53, a first pressure chamber 55, and a first discharge flow path 57. An inflow flow path 51 is formed in the first flow path block 50. One end of the inflow flow path 51 is connected to an inflow port 52 opened to the outside of the first flow path block 50, and the other end of the inflow flow path 51 is connected to the first suction flow path 53. One end of a pipe or the like is connected to the inflow port 52, and the other end of the pipe or the like is inserted into the liquid fertilizer stored in the liquid fertilizer tank. A first suction flow path 53 is connected to one end of the first pressure chamber 55, and a first discharge flow path 57 is connected to the other end of the first pressure chamber 55. The first pressure chamber 55 is partitioned by a first diaphragm 54 (first reciprocating member).

Similarly, the second flow path block 60 is formed with a second suction flow path 63, a second pressure chamber 65, and a second discharge flow path 67. A second suction flow path 63 is connected to one end of the second pressure chamber 65, and a second discharge flow path 67 is connected to the other end of the second pressure chamber 65. The second discharge flow path 67 is connected to an outlet 68 through which liquid fertilizer flows out. The second pressure chamber 65 is partitioned by a second diaphragm 64 (second reciprocating member).

The first suction flow path 53 and the second suction flow path 63 are provided with check valves 71 and 72 for circulating liquid fertilizer only in the directions of flowing into the first pressure chamber 55 and the second pressure chamber 65, respectively. The first discharge flow path 57 and the second discharge flow path 67 are provided with check valves 73 and 74 for circulating liquid fertilizer only in the direction of outflow from the first pressure chamber 55 and the second pressure chamber 65, respectively.

The first suction flow path 53 and the second suction flow path 63 are connected by a tube 75. The tube 75 (tube portion) is formed of a transparent resin tube. A bubble sensor 81 is attached to the tube 75. That is, in the tube 75, the bubble sensor 81 is attached between the inflow port 52 and the second suction flow path 63. The bubble sensor 81 (first bubble sensor) is an optical bubble sensor and is fixed to the main body 31. The bubble sensor 81 detects bubbles contained in the liquid fertilizer flowing in the tube 75 based on the light transmitted through the tube 75. The bubble sensor 81 outputs the detection result of bubbles to the control unit 90. The inflow flow path 51 and the tube 75 form a suction side connection flow path.

Similarly, the first discharge flow path 57 and the second discharge flow path 67 are connected by a tube 76. The tube 76 (tube portion) is formed of a transparent resin tube. A bubble sensor 82 is attached to the tube 76. That is, in the tube 76, the bubble sensor 82 is attached between the second discharge flow path 67 and the outlet 68. The bubble sensor 82 (second bubble sensor) is fixed to the main body 31. The bubble sensor 82 is a bubble sensor similar to the bubble sensor 81. The bubble sensor 82 outputs the detection result of bubbles to the control unit 90. The tube 76 constitutes a discharge-side connection flow path.

The tubes 75 and 76 are flexible and may bend and hang down due to their own weight. In that case, there is a possibility that the attachment of the tubes 75 and 76 may be hindered and the liquid may easily leak from the connection portion of the tubes 75 and 76.

In this regard, stainless steel tubes 77A and 77B (metal tubes) are fitted on the outer periphery of the portion of the tube 75 other than the portion to which the bubble sensor 81 is attached. Similarly, in the tube 76, stainless steel tubes 78A and 78B (metal tubes) are fitted on the outer periphery of the portion other than the portion to which the bubble sensor 82 is attached. One end of the stainless steel tubes 77A and 78B is fixed to the main body 31. One end of the stainless steel tubes 77B and 78A is fixed to the main body 31. The tubes 75 and 76 are housed inside the main body 31, the first flow path block 50, the second flow path block 60, and the lid 39 (see FIG. 3).

The inflow flow path 51, the first suction flow path 53, the first discharge flow path 57, the second suction flow path 63, the second discharge flow path 67, the tube 75, and the tube 76 are arranged along a common plane. There is. Specifically, the central axes of the inflow flow path 51, the first suction flow path 53, the first discharge flow path 57, the second suction flow path 63, the second discharge flow path 67, the tube 75, and the tube 76 are common. It is arranged on the plane of.

The first diaphragm 54 and the second diaphragm 64 are connected by a connecting member 46. The connecting member 46 includes rod portions 47A and 47B and a plate-shaped portion 48. The rod portions 47A and 47B are formed in a columnar shape. The plate-shaped portion 48 is formed in a rectangular plate shape. One end of the rod portion 47A is connected to the first diaphragm 54, and the other end of the rod portion 47A is connected to the plate-shaped portion 48. One end of the rod portion 47B is connected to the second diaphragm 64, and the other end of the rod portion 47B is connected to the plate-shaped portion 48.

As shown in FIG. 3, the main body 31 has a protruding portion 32 protruding to the opposite side of the motor portion 20. The end surface 32a of the protrusion 32 (first sliding member) is perpendicular to the output shaft 21. The main surface 48a (first main surface) facing the end surface 32a in the plate-shaped portion 48 is parallel to the end surface 32a. In the plate-shaped portion 48, the main surface 48b (second main surface), which is the back surface of the main surface 48a, is parallel to the main surface 48a. The main surfaces 48a and 48b are the two largest surfaces of the rectangular plate-shaped plate-shaped portion 48.

The guide member 34 is arranged so as to face the main surface 48b. The guide member 34 (second sliding member) is fixed to the main body 31. The surface 34a of the guide member 34 facing the main surface 48b is parallel to the main surface 48b.

The first sliding member 35 is attached to each diagonal of the main surface 48a of the plate-shaped portion 48. As shown in FIG. 4, the second sliding member 36 is attached to each diagonal of the main surface 48b of the plate-shaped portion 48 so as not to overlap with the first sliding member 35. That is, the first sliding member 35 and the second sliding member 36 are attached to the front surface and the back surface of the plate-shaped portion 48, respectively. Further, the first sliding member 35 and the second sliding member 36 are attached to the plate-shaped portion 48 at positions where they do not overlap. The sliding members 35 and 36 are formed in a plate shape by a material having a small coefficient of friction with the protruding portion 32 and the guide member 34, for example, fluororesin or the like. The sliding members 35 and 36 are attached to the plate-shaped portion 48 by screws (mounting members), respectively. The sliding members 35 and 36 are slidable with respect to the protrusion 32 and the guide member 34, respectively. Further, the rotation of the connecting member 46 around the rod portions 47A and 47B is regulated by the sliding members 35 and 36, the protruding portion 32, and the guide member 34.

A through hole 49 is formed in the plate-shaped portion 48. The crankpin 42 and the roller 45 are inserted into the through hole 49. The width Wx of the through hole 49 in the x direction (direction of the center line of the rod portions 47A and 47B) connecting the first pressure chamber 55 and the second pressure chamber 65 is substantially equal to the outer diameter of the roller 45. The width Wy of the through hole 49 in the y direction perpendicular to the crank pin 42 and perpendicular to the x direction is wider than the range in which the roller 45 moves in the y direction when the roller 45 revolves around the crank shaft 41. ..

The rod portions 47A and 47B are supported by the support portions 37A and 37B of the main body 31 so as to be reciprocating in the x direction, respectively. Further, the rotation of the connecting member 46 around the crank shaft 41 or the crank pin 42 is regulated by the support portions 37A and 37B. The functions of the support portions 37A and 37B may be realized by a support member such as a bearing.

Then, by rotating the output shaft 21 of the motor unit 20, the connecting member 46 is reciprocated in the x direction. As a result, the first pressure chamber 55 is reduced by the first diaphragm 54, and the second pressure chamber 65 is expanded by the second diaphragm 64. Therefore, the liquid fertilizer is discharged from the first pressure chamber 55, and the liquid fertilizer is sucked into the second pressure chamber 65. Subsequently, the first pressure chamber 55 is expanded by the first diaphragm 54, and the second pressure chamber 65 is reduced by the second diaphragm 64. Therefore, the liquid fertilizer is sucked into the first pressure chamber 55, and the liquid fertilizer is discharged from the second pressure chamber 65. That is, liquid fertilizer is alternately discharged from the pressure chambers 55 and 65. The crank mechanism 40 is composed of a crank shaft 41, a crank pin 42, a bearing 44, a roller 45, and a connecting member 46. The drive mechanism is composed of a crank mechanism 40, sliding members 35 and 36, a guide member 34, a main body 31 (protruding portions 32, support portions 37A and 37B), and diaphragms 54 and 64.

The longitudinal direction of the tube 75 and the longitudinal direction of the tube 76 are parallel to the reciprocating direction (x direction) of the connecting member 46. That is, in the space inside the main body 31, the tube 75, the bubble sensor 81 and the tube 76, and the bubble sensor 82 are arranged on both sides of the connecting member 46, respectively. As shown in FIG. 3, this space is closed by a lid 39. The lid 39 is formed in a plate shape by a resin or the like that blocks ultraviolet rays. The housing is composed of the main body 31, the first flow path block 50, the second flow path block 60, and the lid 39.

The liquid pump 10 includes a three-way switching valve 84. The three-way switching valve 84 has a valve inlet 85, a first valve outlet 86, and a second valve outlet 87, and switches the connection state of the valve inlet 85, the first valve outlet 86, and the second valve outlet 87. It is a well-known switching valve. The valve inlet 85 is directly connected to the outlet 68, and the liquid fertilizer flowing out from the outlet 68 flows into the valve inlet 85. The first valve outlet 86 is an outlet for discharging liquid fertilizer, and is connected to a pipe or the like for sending liquid fertilizer to a device or the like that uses liquid fertilizer. The second valve outlet 87 is an outlet for discharging air bubbles contained in the liquid fertilizer, and is open upward. That is, the liquid pump 10 is arranged so that the second valve outlet 87 faces upward. Therefore, the suction flow paths 53 and 63 and the discharge flow paths 57 and 67 are parallel to each other in the vertical direction (y direction). The tubes 75 and 76 are parallel to each other in the horizontal direction (x direction). The connection state of the three-way switching valve 84 is controlled by the control unit 90.

The control unit 90 adjusts the rotation speed (rotational speed of the motor) of the output shaft 21 of the motor unit 20 to control the discharge amount of liquid fertilizer. However, the control unit 90 connects the valve inlet 85 and the second valve outlet 87 by the three-way switching valve 84 when the bubble is detected by the bubble sensor 81 or the bubble sensor 82. In this case, the liquid fertilizer is not discharged from the first valve outlet 86, and the liquid discharge amount is not controlled by adjusting the rotation speed of the output shaft 21. Further, the control unit 90 determines that the abnormality occurs when the period in which the bubble is detected by the bubble sensor 81 or the bubble sensor 82 exceeds a predetermined period. When the control unit 90 determines that the abnormality is found, the control unit 90 notifies the abnormality by a warning light or an alarm. That is, the control unit 90 controls the discharge amount of the liquid fertilizer by adjusting the rotation speed of the output shaft 21 of the motor unit 20 on condition that no bubbles are detected by the bubble sensor 81 and the bubble sensor 82.

The present embodiment described in detail above has the following advantages.

By the drive mechanism including the crank mechanism 40 and the diaphragms 54 and 64, the first pressure chamber 55 is reduced and the second pressure chamber 65 is expanded and the first pressure chamber 55 is expanded based on the rotation of the output shaft 21 of the motor unit 20. The expansion of the second pressure chamber 65 and the reduction of the second pressure chamber 65 are alternately performed. Therefore, the liquid fertilizer can be alternately discharged from the first pressure chamber 55 and the second pressure chamber 65, and the pulsation of the liquid fertilizer can be suppressed as compared with the case where the liquid fertilizer is discharged from only one pressure chamber. .. That is, the pulsation of the liquid fertilizer can be suppressed by intentionally discharging the same liquid fertilizer instead of discharging different liquid fertilizers from the two pressure chambers.

-Since the liquid can be circulated from the inflow port 52 to the first suction flow path 53 and the second suction flow path 63 by the tube 75, the space for arranging the flow path on the suction side can be reduced. Similarly, since the liquid can be circulated from the first discharge flow path 57 and the second discharge flow path 67 to the outlet 68 by the tube 76, the space for arranging the flow path on the discharge side can be reduced. Moreover, the first pressure chamber 55 and the second pressure chamber 65 are reduced and expanded by the common drive mechanism. Therefore, the liquid pump 10 can be miniaturized.

The control unit 90 controls the discharge amount of the liquid fertilizer by adjusting the rotation speed of the output shaft 21 of the motor unit 20 on condition that no bubbles are detected by the bubble sensors 81 and 82. Therefore, it is possible to accurately control the discharge amount of the liquid fertilizer by adjusting the rotation speed of the output shaft 21 of the motor unit 20 in a state where the liquid fertilizer does not contain air bubbles. Therefore, even when the flow meter is not used, the discharge amount of the liquid fertilizer can be accurately controlled. On the other hand, when the liquid fertilizer contains air bubbles, the liquid fertilizer discharge amount is not controlled by adjusting the rotation speed of the output shaft 21 of the motor unit 20, so that the liquid fertilizer discharge amount is suppressed from becoming inaccurate. can do.

The liquid fertilizer flow path includes tubes 75,76 formed of transparent resin tubes. The optical bubble sensors 81 and 82 are attached to the transparent tubes 75 and 76, respectively. Therefore, the bubble sensors 81 and 82 can detect bubbles based on the light transmitted through the transparent tubes 75 and 76. According to the transparent resin tube, the light transmitting portion required for the optical bubble sensors 81 and 82 can be easily formed.

-Generally, transparent resin tubes have the property of whitening when exposed to ultraviolet rays for a long period of time. In that case, the accuracy of bubble detection by the bubble sensors 81 and 82 may decrease. In this respect, since the tubes 75 and 76 are housed in the main body 31, the flow path blocks 50 and 60, and the lid 39 that block ultraviolet rays, it is possible to prevent the tubes 75 and 76 from whitening. Further, the optical bubble sensors 81 and 82 can be made smaller than the microwave type bubble sensor, the ultrasonic type bubble sensor, and the like.

-In the tube 75, stainless steel tubes 77A and 77B are fitted on the outer periphery of a portion other than the portion to which the bubble sensor 81 is attached. In the tube 76, stainless steel tubes 78A and 78B are fitted on the outer periphery of a portion other than the portion to which the bubble sensor 82 is attached. Therefore, the stainless steel tubes 77A and 77B can support the tube 75 and prevent the tube 75 from hanging down. The stainless steel tubes 78A and 78B can support the tube 76 and prevent the tube 76 from hanging down. Further, by fixing the stainless steel tubes 77A to 78B, the tubes 75 and 76 can be easily fixed. Therefore, the tubes 75 and 76 can be easily attached, and it is possible to prevent the liquid fertilizer from easily leaking from the connection portion of the tubes 75 and 76.

The liquid pump 10 is attached between the bubble sensor 81 attached between the inflow port 52 and the second suction flow path 63 in the tube 75, and between the first discharge flow path 57 and the outflow port 68 in the tube 76. It is equipped with a bubble sensor 82. Therefore, the bubbles contained in the liquid fertilizer flowing in order from the inflow port 52 to the inflow flow path 51, the tube 75, the second suction flow path 63, the second pressure chamber 65, the second discharge flow path 67, and the outflow port 68 are bubbled. It can be detected by the sensor 81. On the other hand, the bubble sensor contains bubbles contained in the liquid fertilizer that flows in order from the inflow port 52 to the inflow flow path 51, the first suction flow path 53, the first pressure chamber 55, the first discharge flow path 57, the tube 76, and the outflow port 68. It can be detected by 82. Therefore, even when the air bubbles flow only in one of the first suction flow path 53 and the second suction flow path 63, the air bubbles can be detected without leakage.

The longitudinal direction of the tube 75 and the longitudinal direction of the tube 76 are parallel to the longitudinal direction of the connecting member 46. Therefore, the tubes 75, 76 and the bubble sensors 81, 82 can be arranged on the side of the space where the connecting member 46 reciprocates. Therefore, the connecting member 46, the tubes 75, 76, and the bubble sensors 81, 82 can be efficiently arranged in the main body 31, and the liquid pump 10 can be miniaturized.

The connecting member 46 includes a plate-shaped portion 48 formed in a rectangular plate shape, and the first sliding member 35 is attached diagonally to the main surface 48a of the plate-shaped portion 48, respectively, to form the plate-shaped portion 48. The second sliding member 36 is attached diagonally to the main surface 48b so as not to overlap with the first sliding member 35. That is, in the plate-shaped portion 48, the diagonal to which the first sliding member 35 is attached is different from the diagonal to which the second sliding member 36 is attached. Therefore, the first sliding member 35 and the second sliding member 36 do not overlap with each other via the plate-shaped portion 48, and the screw for attaching the first sliding member 35 and the screw for attaching the second sliding member 36 are attached. Can be prevented from interfering with. Therefore, the structure in which the plate-shaped portion 48, the first sliding member 35, and the second sliding member 36 are assembled can be thinned, and the liquid pump 10 can be miniaturized.

The first sliding member 35 slides on the protruding portion 32 arranged in parallel with the plate-shaped portion 48 facing the main surface 48a, and the second sliding member 36 faces the main surface 48b and is a plate. It slides on the guide member 34 arranged in parallel with the shaped portion 48. Therefore, the first sliding member 35 is attached to two of the four corners of the main surface 48a, and the second sliding member 36 is attached to two of the four corners of the main surface 48b. Even so, the rotation of the connecting member 46 about the center line of the rod portions 47A and 47B can be suppressed.

The inflow flow path 51, the first suction flow path 53, the first discharge flow path 57, the second suction flow path 63, the second discharge flow path 67, and the tubes 75, 76 are arranged along a common plane. There is. Therefore, the flow path of the liquid pump 10 can be efficiently arranged along a common plane, and the liquid pump 10 can be made thinner.

The valve inlet 85 of the three-way switching valve 84 is directly connected to the outlet 68 from which the liquid fertilizer flows out. Therefore, a pipe connecting the outlet 68 and the valve inlet 85 is not required, and the liquid pump 10 can be miniaturized. Since the first valve outlet 86 is an outlet for discharging liquid fertilizer, the liquid fertilizer can be discharged from the first valve outlet 86 by connecting the valve inlet 85 and the first valve outlet 86 with the three-way switching valve 84. can. Further, the second valve outlet 87 is an outlet for discharging air bubbles contained in the liquid fertilizer, and is open upward. Therefore, by connecting the valve inlet 85 and the second valve outlet 87 with the three-way switching valve 84, air bubbles can be easily discharged from the second valve outlet 87 opened upward.

When a bubble is detected by the bubble sensor 81 or the bubble sensor 82, the control unit 90 connects the valve inlet 85 and the second valve outlet 87 by the three-way switching valve 84. Therefore, when the liquid fertilizer temporarily contains air bubbles, the air bubbles can be discharged. Further, the control unit 90 determines that the abnormality is obtained when the period in which the bubble is detected by the bubble sensor 81 or the bubble sensor 82 exceeds a predetermined period. Therefore, if it is not possible to prevent the mixing of air bubbles, such as when the pipe connected to the liquid fertilizer inflow port 52 is disconnected or the liquid fertilizer in the liquid fertilizer tank is emptied, it can be determined to be abnormal. ..

It should be noted that the above embodiment can be modified and implemented as follows. The same parts as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.

-The second valve outlet 87 of the three-way switching valve 84 can also be opened in the horizontal direction.

When a bubble is detected by the bubble sensor 81 or the bubble sensor 82, the control unit 90 connects the valve inlet 85 and the second valve outlet 87 by the three-way switching valve 84, and the bubble sensor 81 or the bubble sensor. When the period in which bubbles are detected by 82 exceeds a predetermined period, only one of determining that it is abnormal may be performed. When the control unit 90 only determines that the bubble is abnormal when the period in which the bubble is detected by the bubble sensor 81 or the bubble sensor 82 exceeds a predetermined period, the three-way switching valve 84 may be omitted. can.

-Only a part of the first suction flow path 53, the first discharge flow path 57, the second suction flow path 63, the second discharge flow path 67, and the tubes 75, 76 is arranged along a common plane. You may.

-It is also possible to adopt a configuration in which the longitudinal direction of the tube 75 and the longitudinal direction of the tube 76 are not parallel to the longitudinal direction of the connecting member 46.

The first sliding member 35 can be attached to each of the four corners of the main surface 48a of the plate-shaped portion 48, and the second sliding member 36 can be attached to the four corners of the main surface 48b of the plate-shaped portion 48, respectively.

-One of the bubble sensors 81 and 82 can be omitted. Even in that case, the bubbles contained in the liquid fertilizer flowing through the inflow flow path 51 are alternately sucked into the first pressure chamber 55 and the second pressure chamber 65 and discharged. Therefore, basically, the bubble sensor attached to at least one of the tubes 75 and 76 can detect the bubble contained in the liquid fertilizer.

-The tube 75 and the bubble sensor 81 may be omitted, and the first discharge flow path 57 may be connected to an outlet different from the outlet 68. Then, liquid fertilizer can be discharged from the two outlets to different devices or the like. Even in this case, it has the same advantages as those in the above embodiment, except that the pulsation of the liquid fertilizer can be suppressed and the bubbles can be detected without leakage.

-The tubes 75, 76 and the bubble sensors 81, 82 are omitted, the second suction flow path 63 is connected to an inflow port different from the inflow port 52, and the first discharge flow path 57 is connected to an outflow port different from the outflow port 68. You can also connect. Then, different liquid fertilizers can be sucked from the two inlets, and the liquid fertilizers can be discharged from the two outlets to different devices or the like. In this case, at least one of the first suction flow path 53 and the first discharge flow path 57 may include a tube portion formed of a transparent resin tube, and the bubble sensor 82 may be attached to the tube portion. Further, at least one of the second suction flow path 63 and the second discharge flow path 67 may include a tube portion formed of a transparent resin tube, and the bubble sensor 81 may be attached to the tube portion.

Even with the above configuration, it is possible to accurately control the discharge amount of liquid fertilizer by adjusting the rotation speed of the output shaft 21 of the motor unit 20 in a state where the liquid does not contain air bubbles. Therefore, even when the flow meter is not used, the discharge amount of the liquid fertilizer can be accurately controlled. On the other hand, when the liquid fertilizer contains air bubbles, the liquid fertilizer discharge amount is not controlled by adjusting the rotation speed of the output shaft 21 of the motor unit 20, so that the liquid fertilizer discharge amount is avoided to be inaccurate. be able to. Further, according to the tube portion formed of the transparent resin tube, the light transmitting portion required for the optical bubble sensor can be easily formed. Further, since the tube portion is housed in the main body 31, the first flow path block 50, the second flow path block 60, and the lid 39 that block ultraviolet rays, whitening of the tube portion can be suppressed. Further, the optical bubble sensor can be made smaller than the microwave type bubble sensor, the ultrasonic type bubble sensor, or the like.

-The stainless steel tubes 77A and 78B may be simply sandwiched between the main body 31 and the bubble sensor 81. The stainless steel tubes 77B and 78A may be simply sandwiched between the main body 31 and the bubble sensor 82. Further, the stainless steel tubes 77A to 78B fitted in the tubes 75 and 76 can be omitted.

-As the bubble sensors 81 and 82, an ultrasonic bubble sensor or a microwave bubble sensor can also be adopted. In that case, opaque piping can be used instead of the tubes 75 and 76.

-A piston (reciprocating member) and a cylinder can be adopted instead of the diaphragms 54 and 64. That is, the liquid pump 10 may be a piston type liquid pump.

-The liquid pump 10 is not limited to liquid fertilizer, and may inhale and discharge other liquids such as chemicals and pure water.

10 ... Liquid pump, 20 ... Motor part (motor), 21 ... Output shaft, 30 ... Pump part, 31 ... Main body, 32 ... Protruding part (first sliding member), 32a ... End face, 34 ... Guide member (No. 1) 2 sliding member), 34a ... surface, 35 ... first sliding member, 36 ... second sliding member, 37A ... support part, 37B ... support part, 39 ... lid, 40 ... crank mechanism, 42 ... crankpin , 44 ... bearing, 45 ... roller, 46 ... connecting member, 47A ... rod part, 47B ... rod part, 48 ... plate-shaped part, 48a ... main surface (first main surface), 48b ... main surface (second main surface) ), 49 ... through hole, 50 ... first flow path block, 52 ... inflow port, 53 ... first suction flow path, 54 ... first diaphragm (first reciprocating moving member), 55 ... first pressure chamber, 57 ... 1st discharge flow path, 60 ... 2nd flow path block, 63 ... 2nd suction flow path, 64 ... 2nd diaphragm (second reciprocating moving member), 65 ... 2nd pressure chamber, 67 ... 2nd discharge flow path, 68 ... Outlet, 75 ... Tube (tube part), 76 ... Tube (tube part), 81 ... Bubble sensor (first bubble sensor), 82 ... Bubble sensor (second bubble sensor), 84 ... Three-way switching valve, 85 ... valve inlet, 86 ... first valve outlet, 87 ... second valve outlet, 90 ... control unit.

Claims (9)

The first suction flow path and
The first pressure chamber connected to the first suction flow path and
The first discharge flow path connected to the first pressure chamber and
The second suction flow path and
A second pressure chamber connected to the second suction flow path and
The second discharge flow path connected to the second pressure chamber and
A suction side connection flow path that is connected to the inflow port into which the liquid flows and connects the first suction flow path and the second suction flow path,
A discharge side connection flow path that connects the first discharge flow path and the second discharge flow path and is connected to the outlet from which the liquid flows out.
With the motor
A drive mechanism that alternately reduces the first pressure chamber and the second pressure chamber, and expands the first pressure chamber and reduces the second pressure chamber based on the rotation of the motor.
A bubble sensor attached to at least one of the suction side connection flow path and the discharge side connection flow path and detecting bubbles contained in the liquid flowing in the attached flow path, and a bubble sensor.
A control unit that adjusts the rotation speed of the motor to control the discharge amount of the liquid on condition that the bubble is not detected by the bubble sensor.
Equipped with
At least one of the suction side connection flow path and the discharge side connection flow path includes a tube portion formed of a transparent resin tube.
The bubble sensor is an optical bubble sensor, which is attached to the tube portion.
The tube portion is housed in a housing that blocks ultraviolet rays.
A liquid pump in which a metal tube is fitted on the outer periphery of a portion of the tube portion other than the portion to which the bubble sensor is attached. The suction side connection flow path and the discharge side connection flow path include the tube portion, respectively.
The bubble sensor is a first bubble sensor attached between the inflow port and the second suction flow path in the tube portion of the suction side connection flow path, and the tube portion of the discharge side connection flow path. The liquid pump according to claim 1, further comprising a second bubble sensor mounted between the first discharge flow path and the outlet. The drive mechanism includes a first reciprocating member that reciprocates so as to reduce and expand the first pressure chamber, a second reciprocating member that reciprocates so as to expand and contract the second pressure chamber, and the above. A connecting member for connecting the first reciprocating member and the second reciprocating member is provided.
Based on the rotation of the motor, the connecting member is reciprocated in the direction connecting the first pressure chamber and the second pressure chamber.
The longitudinal direction of the portion connecting the first suction flow path and the second suction flow path in the suction side connection flow path, and the first discharge flow path and the second discharge flow path in the discharge side connection flow path. The liquid pump according to claim 1 or 2 , wherein the longitudinal direction of the portion connecting the and is parallel to the reciprocating direction of the connecting member. The connecting member includes a plate-shaped portion formed in a rectangular plate shape, and includes a plate-shaped portion.
The first sliding member is attached to the diagonal of the first main surface of the plate-shaped portion, and the second sliding member is attached to the diagonal of the second main surface of the plate-shaped portion so as not to overlap with the first sliding member. The parts are attached and
The first sliding member slides on the first sliding member arranged in parallel with the plate-shaped portion facing the first main surface, and the second sliding member is the second main surface. The liquid pump according to claim 3 , wherein the liquid pump slides on a second sliding member arranged in parallel with the plate-shaped portion facing the surface. The first suction flow path and
The first pressure chamber connected to the first suction flow path and
The first discharge flow path connected to the first pressure chamber and
The second suction flow path and
A second pressure chamber connected to the second suction flow path and
The second discharge flow path connected to the second pressure chamber and
A suction side connection flow path that is connected to the inflow port into which the liquid flows and connects the first suction flow path and the second suction flow path,
A discharge side connection flow path that connects the first discharge flow path and the second discharge flow path and is connected to the outlet from which the liquid flows out.
With the motor
A drive mechanism that alternately reduces the first pressure chamber and the second pressure chamber, and expands the first pressure chamber and reduces the second pressure chamber based on the rotation of the motor.
A bubble sensor attached to at least one of the suction side connection flow path and the discharge side connection flow path and detecting bubbles contained in the liquid flowing in the attached flow path, and a bubble sensor.
A control unit that adjusts the rotation speed of the motor to control the discharge amount of the liquid on condition that the bubble is not detected by the bubble sensor.
Equipped with
The drive mechanism includes a first reciprocating member that reciprocates so as to reduce and expand the first pressure chamber, a second reciprocating member that reciprocates so as to expand and contract the second pressure chamber, and the above. A connecting member for connecting the first reciprocating member and the second reciprocating member is provided.
Based on the rotation of the motor, the connecting member is reciprocated in the direction connecting the first pressure chamber and the second pressure chamber.
In the suction side connection flow path, the longitudinal direction of the portion connecting the first suction flow path and the second suction flow path, and in the discharge side connection flow path, the first discharge flow path and the second discharge flow path. The longitudinal direction of the portion connecting the and is parallel to the reciprocating direction of the connecting member.
The connecting member includes a plate-shaped portion formed in a rectangular plate shape, and includes a plate-shaped portion.
The first sliding member is attached to the diagonal of the first main surface of the plate-shaped portion, and the second sliding member is attached to the diagonal of the second main surface of the plate-shaped portion so as not to overlap with the first sliding member. The parts are attached and
The first sliding member slides on the first sliding member arranged in parallel with the plate-shaped portion facing the first main surface, and the second sliding member is the second main surface. A liquid pump that slides on a second sliding member that faces the surface and is arranged in parallel with the plate-shaped portion. The first suction flow path, the first discharge flow path, the second suction flow path, the second discharge flow path, the suction side connection flow path, and the discharge side connection flow path are along a common plane. The liquid pump according to any one of claims 1 to 5 , which is arranged. Equipped with a three-way switching valve having a valve inlet, a first valve outlet, and a second valve outlet.
The valve inlet is directly connected to the outlet and
The first valve outlet is an outlet for discharging the liquid, and is an outlet.
The liquid pump according to any one of claims 1 to 6 , wherein the second valve outlet is an outlet for discharging bubbles contained in the liquid and is open upward. When the bubble is detected by the bubble sensor, the control unit connects the valve inlet and the second valve outlet by the three-way switching valve, and the period during which the bubble is detected by the bubble sensor is The liquid pump according to claim 7 , wherein it is determined to be abnormal when the predetermined period is exceeded. The suction flow path connected to the inflow port where the liquid flows in,
A pressure chamber connected to the suction flow path and
A discharge flow path connecting the pressure chamber and the outlet from which the liquid flows out,
With the motor
A drive mechanism that alternately reduces and expands the pressure chamber based on the rotation of the motor.
A bubble sensor attached to at least one of the suction flow path and the discharge flow path and detecting bubbles contained in the liquid flowing in the attached flow path, and a bubble sensor.
A control unit that adjusts the rotation speed of the motor to control the discharge amount of the liquid on condition that the bubble is not detected by the bubble sensor.
Equipped with
At least one of the suction flow path and the discharge flow path includes a tube portion formed of a transparent resin tube.
The bubble sensor is an optical bubble sensor, which is attached to the tube portion.
The tube portion is housed in a housing that blocks ultraviolet rays.
A liquid pump in which a metal tube is fitted on the outer periphery of a portion of the tube portion other than the portion to which the bubble sensor is attached.

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