Sensor unit and pump device

Abstract

To provide a sensor unit in which while respective functions of a discharge sensor and a relief valve are secured, both members can be compactly arranged, and a pump device.SOLUTION: A sensor unit 10 according to the present invention acquires liquid information related to liquid L discharged from a pump device. The sensor unit has: a flow passage block body 100 containing a flow passage 170 through which the liquid flows; a discharge sensor 200 for acquiring liquid information of the liquid flowing through the flow passage; and a relief valve 400 opened / closed according to pressure applied to the liquid flowing through the flow passage. The flow passage comprises: a sensor flow passage 173 for guiding the liquid to the discharge sensor; a relief flow passage 174 for guiding the liquid to the relief valve; and an introduction flow passage communicating with the sensor flow passage and the relief flow passage, and for guiding the liquid discharged from the pump device to the sensor flow passage and the relief flow passage. The discharge sensor and the relief valve are each attached to the flow passage block body.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a sensor unit and a pump device.

Background Art

[0002] A metering pump such as a reciprocating pump conveys a liquid quantitatively by varying the pressure in a pump chamber provided in the metering pump and repeating the suction and discharge of the liquid in the pump chamber. In a metering pump, if the liquid to be suctioned contains air bubbles, an air bubble accumulation may occur in the pump chamber, and the discharge amount of the liquid from the metering pump may become unstable. Therefore, a discharge sensor (for example, a flow meter) for monitoring the liquid discharged from the metering pump may be attached to a flow path on the discharge side of the metering pump (hereinafter referred to as a "discharge flow path").

[0003] In addition, when problems such as clogging of the discharge flow path and an increase in back pressure from the connection destination of the discharge flow path occur, the flow of the liquid in the discharge flow path stagnates, and the pressure applied to the liquid from the pump chamber to the discharge flow path increases. As a result, the metering pump may malfunction or the discharge flow path may be damaged. Therefore, a relief valve for releasing pressure may also be attached to the discharge flow path.

[0004] The discharge sensor and the relief valve are individually attached to the discharge flow path to ensure each function. Therefore, in the space where the metering pump and the discharge flow path are arranged, not only the discharge sensor and the relief valve, but also members (joints, branch pipes, etc.) for attaching the discharge sensor and the relief valve, and members (pedestals, etc.) for fixing the discharge sensor and the relief valve in the space are arranged. As a result, a relatively large space is required for the arrangement of the discharge flow path to which the discharge sensor and the relief valve are attached. However, usually, the metering pump and the discharge flow path are often arranged in a relatively narrow space such as below a storage tank in which the liquid to be conveyed is stored or beside the storage tank.

[0005] Conventionally, technologies for compactly arranging a discharge sensor and a relief valve on the discharge side of a metering pump have been proposed (see, for example, Patent Document 1).

[0006] In the technology disclosed in Patent Document 1, a discharge sensor is directly connected to the discharge port of a metering pump, and a low-pressure valve and a relief valve are directly connected to the downstream side of the discharge sensor. That is, in this technology, a vertically long space for arranging the metering pump to the relief valve in series linearly is required. However, as described above, the space where the metering pump and the discharge flow path are arranged is generally narrow, and it is difficult to secure a space for arranging the metering pump to the relief valve in series linearly.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] An object of the present invention is to provide a sensor unit and a pump device capable of compactly arranging both members while ensuring the functions of a discharge sensor and a relief valve.

Means for Solving the Problems

[0009] A sensor unit according to an embodiment of the present invention is a sensor unit that acquires liquid information regarding a liquid discharged from a pump device, and includes a flow path block body that encloses a flow path through which the liquid flows, a discharge sensor that acquires the liquid information of the liquid flowing through the flow path, and a relief valve that opens and closes according to a pressure applied to the liquid flowing through the flow path. The flow path includes a sensor flow path that guides the liquid to the discharge sensor, a relief flow path that guides the liquid to the relief valve, an introduction flow path that communicates with the sensor flow path and the relief flow path and guides the liquid discharged from the pump device to the sensor flow path and the relief flow path. One branch point connected to the sensor flow path, the relief flow path, and the introduction flow path comprises, and the discharge sensor Part of and the relief valve are each attached to the flow path block body Inside respectively. The discharge sensor includes a float that floats and sinks according to the flow of the liquid, and a sensor body that detects the flow of the liquid based on the floating and sinking of the float. The flow path block body communicates with the sensor flow path and includes a float chamber in which the float is accommodated. The sensor body is attached to the outer surface of the flow path block body, and a part of the flow path block body that constitutes the float chamber functions as a housing of the discharge sensor in which the float is accommodated .

[0010] A pump device according to an embodiment of the present invention includes a pump head that sucks a liquid and discharges the sucked liquid, and the above-described sensor unit connected to the pump head.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a sensor unit and a pump device in which each function of the discharge sensor and the relief valve is ensured and the two members can be arranged compactly.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the sensor unit and the pump device according to the present invention will be described with reference to the drawings. In each figure, the same members and elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0014] In the following description and drawings, unless otherwise specified, when three axes mutually orthogonal in space are defined as the X-axis, Y-axis, and Z-axis respectively, the "X-axis direction" is the direction along the X-axis, which is the left-right direction (the width direction of the sensor unit) in the sensor unit according to the present invention. The "Y-axis direction" is the direction along the Y-axis, which is the front-back direction (the depth (thickness) direction of the sensor unit) in the sensor unit. The "Z-axis direction" is the direction along the Z-axis, which is the up-down direction (the height direction of the sensor unit) in the sensor unit. Also, in the sensor unit, the "+X-axis direction" is to the left, the "-X-axis direction" is to the right, the "+Y-axis direction" is to the front, the "-Y-axis direction" is to the back, the "+Z-axis direction" is upward, and the "-Z-axis direction" is downward.

[0015] ●Sensor unit (1)● First, an embodiment of the sensor unit according to the present invention will be described.

[0016] ●Connection example of sensor unit (1) FIG. 1 is a schematic diagram showing a connection example of the sensor unit according to the present invention.

[0017] The sensor unit 10 acquires liquid information (in this embodiment, the presence or absence of the flow of the liquid L) regarding the liquid L discharged from the metering pump P. The sensor unit 10 is connected to the discharge flow path FR1 via the joint 31, connected to the connection flow path FR2 via the joint 32, and connected to the external discharge flow path FR3 via the joint 33.

[0018] The metering pump P is, for example, an electromagnetic drive type diaphragm pump. The metering pump P is an example of a pump device that discharges the liquid L for which the sensor unit 10 acquires liquid information.

[0019] The liquid L is, for example, an aqueous sodium hypochlorite solution added to water.

[0020] "Liquid information" is information regarding the liquid L, and includes, for example, information regarding the dynamic state of the liquid L such as the presence or absence of the flow of the liquid L, and information indicating physical quantities of the liquid L such as the flow rate of the liquid L. In the present embodiment, the liquid information is the presence or absence of the flow of the liquid L.

[0021] The joints 31 to 33 are known hose joints that detachably connect tubular bodies (such as hoses and tubes). At one end of each of the joints 32 and 33, for example, male threaded surfaces 32a and 33a (see FIG. 4) that can be screwed into corresponding female threaded surfaces (female threaded holes) are arranged. Here, the configuration of each of the joints 31 to 33 may be common or different according to the corresponding connection destination.

[0022] The discharge flow path FR1 is a flow path through which the liquid L discharged from the metering pump P flows. The connection flow path FR2 is a flow path through which the liquid L for which liquid information has been acquired by the sensor unit 10 flows. The external discharge flow path FR3 is a flow path through which the liquid L discharged from a relief valve 400 (see FIG. 2) described later flows. The discharge flow path FR1, the connection flow path FR2, and the external discharge flow path FR3 are, for example, tubes made of synthetic resin.

[0023] ● Configuration of the sensor unit (1) FIG. 2 is a perspective view showing an embodiment of the sensor unit according to the present invention. This figure also shows the three joints 31 to 33 attached to the sensor unit 10.

[0024] The sensor unit 10 includes a flow path block body 100, a discharge sensor 200, a stopper 300, a relief valve 400, and an air vent valve 500.

[0025] FIG. 3 is a cross-sectional view of the sensor unit 10 in FIG. 2 in a virtual plane. FIG. 4 is an exploded cross-sectional view of the sensor unit 10 in FIG. 2 in a virtual plane. Here, the "virtual plane" is a plane (XZ plane parallel to the X-axis direction and the Z-axis direction) passing through the center in the front-rear direction of the sensor unit 10. FIGS. 3 and 4 show together the three joints 31 to 33 attached to the sensor unit 10. Further, FIG. 3 shows the discharge flow path FR1, the connection flow path FR2, and the external discharge flow path FR3 respectively connected to the sensor unit 10 via the joints 31 to 33 by thick dashed lines.

[0026] The flow path block body 100 encloses a flow path 170 described later and also functions as a housing for the discharge sensor 200 and the relief valve 400. The shape of the flow path block body 100 is a substantially rectangular parallelepiped shape that is flat in the front-rear direction (depth direction). The length of the flow path block body 100 in the vertical direction (height direction) is shorter than the length in the left-right direction (width direction). The flow path block body 100 is made of a transparent synthetic resin such as PMMA (Polymethyl methacrylate) or PVC (Polyvinyl chloride). The flow path block body 100 includes a first joint attachment portion 110, a second joint attachment portion 120, a third joint attachment portion 130, a float accommodation portion 140, a relief valve attachment portion 150, an air vent valve attachment portion 160, a flow path 170, and a sensor attachment portion 180.

[0027] The first joint attachment portion 110 is a portion of the flow path block body 100 to which the joint 31 is attached. The first joint attachment portion 110 is disposed in the right half of the lower surface 100c of the flow path block body 100. The first joint attachment portion 110 projects downward from the lower surface 100c of the flow path block body 100 in a substantially cylindrical shape. The first joint attachment portion 110 includes a fitting hole 110a into which a part (upper portion) of the joint 31 is fitted. The fitting hole 110a is a frustum-shaped hole that extends along the vertical direction and expands in diameter downward. The fitting hole 110a (in other words, the first joint attachment portion 110) is disposed at the lower end portion within the flow path block body 100.

[0028] The second joint attachment portion 120 is a portion of the flow path block body 100 where the joint 32 is attached. The second joint attachment portion 120 is a vertically-flattened cylindrical hole along the vertical direction. The second joint attachment portion 120 is disposed in the left half of the upper surface 100a of the flow path block body 100 and opens upward. That is, the second joint attachment portion 120 is disposed at the upper end portion within the flow path block body 100. The inner peripheral surface 120a of the second joint attachment portion 120 is a female screw surface corresponding to the male screw surface 32a of the joint 32.

[0029] The third joint attachment portion 130 is a portion of the flow path block body 100 where the joint 33 is attached. The third joint attachment portion 130 is a horizontally-flattened cylindrical hole along the horizontal direction. The third joint attachment portion 130 is disposed in the upper half of the right surface 100b of the flow path block body 100 and opens rightward. That is, the third joint attachment portion 130 is disposed at the right end portion within the flow path block body 100. The inner peripheral surface 130a of the third joint attachment portion 130 is a female screw surface corresponding to the male screw surface 33a of the joint 33.

[0030] The float accommodation portion 140 is a portion of the flow path block body 100 where a float 210 and a stopper 300, which will be described later, are accommodated. The float accommodation portion 140 is a cylindrical hole along the vertical direction. The float accommodation portion 140 is disposed below the second joint attachment portion 120 within the flow path block body 100. In a top view, the center line of the float accommodation portion 140 overlaps with the center line of the second joint attachment portion 120. The inner diameter of the upper portion (hereinafter referred to as the "large-diameter portion") 141 of the float accommodation portion 140 is larger than the inner diameter of the other portion (hereinafter referred to as the "small-diameter portion") 142 of the float accommodation portion 140. The large-diameter portion 141 communicates with the second joint attachment portion 120. The small-diameter portion 142 defines a float chamber R1 that accommodates the float 210. The large-diameter portion 141 defines a stopper chamber R2 that accommodates the stopper 300. A groove 142a along the vertical direction is disposed on the inner peripheral surface of the small-diameter portion 142.

[0031] The relief valve mounting portion 150 is a portion of the flow path block body 100 where the relief valve 400 is mounted. The relief valve mounting portion 150 is a cylindrical hole along the vertical direction. The relief valve mounting portion 150 is disposed in the right half of the upper surface 100a of the flow path block body 100 and opens upward. The relief valve mounting portion 150 is disposed above the fitting hole 110a and to the right of the float accommodating portion 140 within the flow path block body 100. In a top view, the center line of the relief valve mounting portion 150 overlaps with the center line of the fitting hole 110a. A part of the inner peripheral surface 151a of the upper half 151 of the relief valve mounting portion 150 is a female thread surface corresponding to the male thread surface (outer peripheral surface 431a) of a retainer 430 described later. The lower half 152 of the relief valve mounting portion 150 defines a valve chamber R3 that houses a valve body 410 and a biasing member 420 described later. The lower end surface 152a of the relief valve mounting portion 150 is an inclined surface in the shape of an inverted frustum of a cone.

[0032] The air vent valve mounting portion 160 is a portion of the flow path block body 100 where the air vent valve 500 is mounted. The air vent valve mounting portion 160 is a cylindrical hole along the left - right direction. The air vent valve mounting portion 160 is disposed in the lower half of the right surface 100b of the flow path block body 100 and opens to the right. That is, the air vent valve mounting portion 160 is disposed at the right end within the flow path block body 100. The inner peripheral surface 160a of the air vent valve mounting portion 160 is a female thread surface corresponding to the male thread surface (outer peripheral surface 500a) of the air vent valve 500 described later.

[0033] The flow path 170 guides the liquid L to the float chamber R1 and the valve chamber R3 in the flow path block body 100. The flow path 170 is disposed within the flow path block body 100. That is, the flow path block body 100 encloses the flow path 170. The flow path 170 includes an introduction flow path 171, a branch portion 172, a sensor flow path 173, a relief flow path 174, an air vent flow path 175, and a discharge flow path 176.

[0034] The introduction flow path 171 guides the liquid L from the discharge flow path FR1 to the sensor flow path 173, the relief flow path 174, and the air venting flow path 175. The introduction flow path 171 is a cylindrical hole along the vertical direction. The lower end of the introduction flow path 171 is connected to the upper end of the fitting hole 110a of the first joint attachment portion 110. The upper end of the introduction flow path 171 is connected to the branch portion 172. That is, the introduction flow path 171 communicates with the fitting hole 110a and the branch portion 172. That is, the fitting hole 110a communicates with the branch portion 172 via the introduction flow path 171.

[0035] The branch portion 172 is a four-way branch point connected to each of the introduction flow path 171, the sensor flow path 173, the relief flow path 174, and the air venting flow path 175. That is, each of the introduction flow path 171, the sensor flow path 173, the relief flow path 174, and the air venting flow path 175 communicates with each other via the branch portion 172.

[0036] The sensor flow path 173 guides the liquid L from the introduction flow path 171 to the float chamber R1. The sensor flow path 173 includes a first sensor flow path 173a and a second sensor flow path 173b.

[0037] The first sensor flow path 173a is a cylindrical hole along the horizontal direction. The left end of the first sensor flow path 173a is connected to the branch portion 172. The right end of the first sensor flow path 173a is connected to the lower end of the second sensor flow path 173b. That is, the first sensor flow path 173a communicates with the branch portion 172 and the second sensor flow path 173b. That is, the branch portion 172 communicates with the second sensor flow path 173b via the first sensor flow path 173a.

[0038] The second sensor flow path 173b is a columnar hole along the vertical direction. The upper end of the second sensor flow path 173b is connected to the lower end of the float chamber R1. That is, the second sensor flow path 173b communicates with the first sensor flow path 173a and the float chamber R1. That is, the first sensor flow path 173a communicates with the float chamber R1 via the second sensor flow path 173b. The portion of the sensor flow path 173 on the branch portion 172 side extends along the horizontal direction, and the portion on the float chamber R1 side extends along the vertical direction. That is, in a front view, the shape of the sensor flow path 173 is L-shaped.

[0039] The relief flow path 174 guides the liquid L from the introduction flow path 171 to the valve chamber R3. The relief flow path 174 is a columnar hole along the vertical direction. The upper end of the relief flow path 174 is connected to the lower end of the valve chamber R3. The lower end of the relief flow path 174 is connected to the branch portion 172. That is, the relief flow path 174 communicates with the branch portion 172 and the valve chamber R3. That is, the branch portion 172 communicates with the valve chamber R3 via the relief flow path 174.

[0040] The air vent flow path 175 guides the bubbles in the flow path 170 to the outside of the flow path block body 100. The air vent flow path 175 is a columnar hole along the horizontal direction. The right end of the air vent flow path 175 is connected to the left end of the air vent valve mounting portion 160. The left end of the air vent flow path 175 is connected to the branch portion 172. That is, the air vent flow path 175 communicates with the branch portion 172 and the air vent valve mounting portion 160. That is, the branch portion 172 communicates with the air vent valve mounting portion 160 via the air vent flow path 175.

[0041] Here, the air vent valve mounting portion 160 and the air vent flow path 175 are processing holes (so-called waste holes) required when forming the first sensor flow path 173a in the flow path block body 100. In the sensor unit 10, such processing holes can be effectively utilized as air vent holes.

[0042] The discharge flow path 176 guides the liquid L from the valve chamber R3 to the third joint attachment portion 130. The discharge flow path 176 is a cylindrical hole along the left - right direction. The right end of the discharge flow path 176 is connected to the right end of the third joint attachment portion 130. The left end of the discharge flow path 176 is connected to the right end (inner peripheral surface) of the valve chamber R3. That is, the discharge flow path 176 communicates with the valve chamber R3 and the third joint attachment portion 130. In other words, the valve chamber R3 communicates with the third joint attachment portion 130 via the discharge flow path 176.

[0043] In the flow path block body 100, the center lines of the introduction flow path 171, the sensor flow path 173, the relief flow path 174, the air vent flow path 175, and the discharge flow path 176 are arranged on a common virtual plane (XZ plane) together with the center lines of the fitting hole 110a, the second joint attachment portion 120, the third joint attachment portion 130, the float accommodation portion 140, the relief valve attachment portion 150, and the air vent valve attachment portion 160 respectively. In other words, the center lines of the fitting hole 110a, the second joint attachment portion 120, the third joint attachment portion 130, the float accommodation portion 140, the relief valve attachment portion 150, the air vent valve attachment portion 160, the introduction flow path 171, the sensor flow path 173, the relief flow path 174, the air vent flow path 175, and the discharge flow path 176 are arranged without deviation in the front - rear direction. As a result, even when these elements are arranged in the flow path block body 100, the thickness (length in the front - rear direction) of the flow path block body 100 can be made small. The center lines of the fitting hole 110a, the relief valve attachment portion 150, the introduction flow path 171, and the relief flow path 174 are arranged on the same virtual straight line C1. The center lines of the second joint attachment portion 120, the float accommodation portion 140, and the second sensor flow path 173b are arranged on the same virtual straight line C2. The center lines of the first sensor flow path 173a and the air vent flow path 175 are arranged on the same virtual straight line C3. The center line of the first sensor flow path 173a is orthogonal to the center lines of the introduction flow path 171 and the relief flow path 174 respectively. The virtual straight line C1 and the virtual straight line C2 are parallel in the up - down direction. The virtual straight line C3 is parallel in the left - right direction and is orthogonal to the virtual straight lines C1 and C2.

[0044] The length of the introduction channel 171 is the same as the length of the relief channel 174. The length of the first sensor channel 173a is longer than the length of the relief channel 174 (for example, about 3.4 times). The length of the second sensor channel 173b is longer than the length of the relief channel 174 (for example, about 2.9 times). That is, the length of the sensor channel 173 is longer than the length of the relief channel 174 (for example, about 6.3 times). The length of the first sensor channel 173a is longer than the length of the second sensor channel 173b (for example, about 1.2 times).

[0045] Among the inner diameters of the channels 170, the inner diameter of the relief channel 174 is larger than the inner diameters of the introduction channel 171, the sensor channel 173, and the air vent channel 175 respectively, and is the same as the inner diameter of the discharge channel 176.

[0046] The sensor mounting portion 180 is a portion of the flow path block body 100 where the sensor main body 220 of the discharge sensor 200 described later is mounted. The sensor mounting portion 180 is a recess in which a part of the left surface 100d of the flow path block body 100 is recessed in a rectangular shape toward the right (the side where the float chamber R1 is arranged). The sensor mounting portion 180 is arranged at the center of the left surface 100d in the vertical direction. The upper half of the sensor mounting portion 180 is arranged to the left of the lower half of the float housing portion 140. That is, the sensor mounting portion 180 is arranged to the left of the float chamber R1. The lower half of the sensor mounting portion 180 is arranged to the left of the second sensor channel 173b. In the vertical direction, the sensor mounting portion 180 has a length such that when the float 210 described later sinks, the sensor main body 220 described later can be arranged on the side of the magnet 212 described later. The sensor mounting portion 180 is provided with two female screw holes 180a (one is not shown. The same applies hereinafter).

[0047] The female screw hole 180a is a hole corresponding to the mounting screw 250 described later. The female screw holes 180a are arranged side by side in the front-rear direction of the lower half of the sensor mounting portion 180. The female screw holes 180a extend forward and backward respectively toward the front and rear of the second sensor channel 173b.

[0048] The discharge sensor 200 acquires liquid information. The discharge sensor 200 is, for example, a flow sensor that detects the presence or absence of the flow of the liquid L. The discharge sensor 200 includes a float 210, a sensor body 220, a cable 230, a cover 240, and two mounting screws 250 (see also FIG. 2).

[0049] The float 210 floats (moves) up and down according to the flow of the liquid L in the float chamber R1. The float 210 includes a float body 211 and a magnet 212. The float 210 is housed in the float chamber R1 (small-diameter portion 142) of the flow path block body 100. That is, a part (float 210) of the discharge sensor 200 is attached inside the flow path block body 100.

[0050] The float body 211 is made of a synthetic resin such as PP (polypropylene) or PVC, for example. The shape of the float body 211 is, for example, columnar along the vertical direction.

[0051] The magnet 212 is a permanent magnet such as a neodymium magnet, for example. The magnet 212 is, for example, disk-shaped. The magnet 212 is disposed (embedded) inside the float body 211 with its S pole facing downward, for example.

[0052] The sensor body 220 detects the presence or absence of the flow of the liquid L based on the floating and sinking of the float 210. The sensor body 220 is a known magnetic sensor that detects the magnitude of a magnetic field that changes based on the position of the magnet 212 of the float 210, for example.

[0053] The cable 230 is a signal line that transmits an electrical signal from the sensor body 220.

[0054] The cover 240 protects the sensor body 220. The cover 240 is made of a synthetic resin such as PP, for example. The shape of the cover 240 is a rectangular parallelepiped shape that is flat in the left - right direction. The cover 240 includes a housing portion 241 that houses the sensor body 220, and two insertion holes (not shown; the same applies hereinafter) through which the mounting screw 250 is inserted. The housing portion 241 is disposed in the upper half of the right surface of the cover 240. The insertion holes are arranged side - by - side in the front - rear direction in the lower half of the cover 240 and penetrate the cover 240 in the left - right direction.

[0055] The mounting screw 250 is a screw for attaching the cover 240 to the sensor mounting portion 180. The mounting screw 250 is, for example, a Urya screw.

[0056] The sensor body 220 is attached to the sensor mounting portion 180 by screwing the mounting screw 250 inserted through the insertion hole into the female screw hole 180a of the sensor mounting portion 180. At this time, the sensor body 220 is disposed to the left of the lower end of the float chamber R1. That is, the sensor body 220 is disposed to the left of the float 210 when the float 210 has settled and is located at the lower end of the float chamber R1.

[0057] In this way, when the discharge sensor 200 is attached to the flow path block body 100, when there is no flow of the liquid L in the float chamber R1, the float 210 is located (settled) at the lower end of the float chamber R1. At this time, the sensor body 220 does not output an electrical signal indicating that there is a flow. On the other hand, when there is a flow of the liquid L in the float chamber R1, the float 210 moves (floats) toward the upper end of the float chamber R1. When the float 210 moves (floats) beyond a predetermined position, the sensor body 220 outputs an electrical signal.

[0058] The stopper 300 restricts the upward movement of the float 210. The stopper 300 is made of a synthetic resin such as PP, for example. The shape of the stopper 300 is, for example, a cylindrical shape along the up - down direction. The inner diameter of the lower end portion of the stopper 300 is smaller than the outer diameter of the float 210. The stopper 300 is housed in the stopper chamber R2.

[0059] The relief valve 400 is a known relief valve that opens and closes in response to the pressure applied to the liquid L in the flow path 170 (particularly, the relief flow path 174). The relief valve 400 opens, for example, when the pressure applied to the liquid L in the flow path 170 exceeds a predetermined value (the value of the biasing force described later), and closes when the pressure is below the predetermined value. The relief valve 400 includes a valve body 410, a biasing member 420, and a retainer 430.

[0060] The valve body 410 is a valve that opens and closes in response to the pressure applied to the liquid L in the flow path 170. The valve body 410 includes an inverted conical lid portion 411, a columnar shaft portion 412, and an O-ring 413. The shaft portion 412 projects upward from the upper surface of the lid portion 411. The O-ring 413 is attached to the conical surface of the lid portion 411.

[0061] The biasing member 420 biases the valve body 410 in the direction in which the valve body 410 closes (downward). The biasing member 420 is, for example, a coil spring.

[0062] The retainer 430 holds the biasing member 420 in the valve chamber R3. The retainer 430 includes, for example, a columnar fixing portion 431 and a columnar shaft portion 432. The outer peripheral surface 431a of the lower half of the fixing portion 431 is a male screw surface corresponding to the female screw surface of the upper half 151 of the relief valve mounting portion 150. The shaft portion 432 projects downward from the lower surface of the fixing portion 431.

[0063] The valve body 410 is accommodated in the valve chamber R3 with the conical surface facing downward. The biasing member 420 is accommodated in the valve chamber R3 and is disposed above the valve body 410. The retainer 430 is screwed into the upper half 151 of the relief valve mounting portion 150 from the opening of the relief valve mounting portion 150. Thus, the relief valve 400 is attached to the relief valve mounting portion 150. In other words, a part of the relief valve 400 (the valve body 410, the biasing member 420, and a part of the retainer 430) is attached within the flow path block body 100. As a result, the lower half 152 of the relief valve mounting portion 150 and the retainer 430 define the valve chamber R3. Further, the biasing member 420 is compressed downward by the retainer 430 and biases the valve body 410 downward with a predetermined force (hereinafter referred to as "biasing force"). At this time, the shaft portions 412 and 432 are disposed inside the biasing member 420 and function as shafts when the biasing member 420 expands and contracts. The biasing force is adjusted, for example, by the screwing amount of the retainer 430. The value of the biasing force is, for example, 1 MPa.

[0064] The air vent valve 500 is a valve that is opened, for example, by a user (hereinafter referred to as "user") of the sensor unit 10 when removing (generating) air bubbles that have entered the flow path 170. The shape of the air vent valve 500 is a columnar shape along the left-right direction. The outer peripheral surface 500a of the left half of the air vent valve 500 is a male screw surface corresponding to the female screw surface of the inner peripheral surface 160a of the air vent valve mounting portion 160. The air vent valve 500 is screwed into the air vent valve mounting portion 160.

[0065] In the flow path 170, the sensor flow path 173 and the relief flow path 174 are connected in parallel to the introduction flow path 171. In the left-right direction, the lower half of the float chamber R1 is arranged side by side with the upper half of the valve chamber R3. The sensor body 220 is disposed to the left of the lower end of the float chamber R1. Further, the center line of the float chamber R1 is parallel to the center line of the valve chamber R3. Therefore, the discharge sensor 200 is arranged side by side with the relief valve 400 in the left-right direction.

[0066] In the sensor unit 10 configured as described above, the joint 31 is fitted into the first joint mounting portion 110, the joint 32 is screwed into the second joint mounting portion 120, and the joint 33 is screwed into the third joint mounting portion 130. The discharge flow path FR1 is connected to the joint 31, the connection flow path FR2 is connected to the joint 32, and the external discharge flow path FR3 is connected to the joint 33. As a result, the discharge flow path FR1 communicates with the introduction flow path 171 via the joint 31. The connection flow path FR2 communicates with the stopper chamber R2 via the joint 32. The external discharge flow path FR3 communicates with the discharge flow path 176 via the joint 33.

[0067] ● Operation of the sensor unit (1) Next, with reference to FIGS. 3 to 5, the operation of the sensor unit 10 will be described.

[0068] FIG. 5 is a schematic diagram of the sensor unit 10 connected to the metering pump P. FIG. 5(a) shows a state where the metering pump P is not operating, FIG. 5(b) shows a state where the metering pump P is operating, and FIG. 5(c) shows a state where a pressure equal to or greater than the biasing force is applied to the liquid L in the flow path 170 in the state of FIG. 5(b). In the figure, the portions through which the liquid L is flowing in each of the flow paths 170, FR1 to FR3 are indicated by thick solid lines.

[0069] First, when the metering pump P is not operating, as shown in FIG. 5(a), the liquid L does not flow into the sensor unit 10. Therefore, the liquid L does not flow in the flow path 170. Accordingly, the float 210 is located at the lower end (non-detection position) of the float chamber R1. At this time, the sensor main body 220 does not detect the movement (rise) of the float 210 (magnet 212) and does not output an electrical signal.

[0070] Next, when the metering pump P is operating, as shown in FIG. 5(b), the liquid L is guided to the flow path 170 of the sensor unit 10 through the discharge flow path FR1 and the joint 31. At this time, the pressure applied to the liquid L in the flow path 170 is smaller than the biasing force, and the relief valve 400 is closed. As a result, the sensor unit 10 guides the liquid L to the joint 32 (connection flow path FR2) through the introduction flow path 171, the branch portion 172, the sensor flow path 173, the float chamber R1, and the stopper chamber R2.

[0071] When the liquid L flows through the float chamber R1, the float 210 moves (rises) toward the upper end of the float chamber R1 according to the flow of the liquid L. When the float 210 moves (rises) beyond a predetermined position (detection position), the sensor main body 220 detects the movement (rise) of the float 210 (magnet 212) and outputs an electrical signal. The detection position is set in advance.

[0072] Next, in the state shown in FIG. 5(b), for example, when the connection flow path FR2 is clogged, the pressure applied to the liquid L in the flow path 170 increases due to the liquid L discharged from the metering pump P. Then, when the metering pump P operates and a pressure equal to or greater than the biasing force is applied to the liquid L in the flow path 170, the valve body 410 rises against the biasing force, and the relief valve 400 opens. As a result, as shown in FIG. 5(c), the sensor unit 10 guides the liquid L to the joint 33 (external discharge flow path FR3) through the introduction flow path 171, the branch portion 172, the relief flow path 174, the valve chamber R3, and the discharge flow path 176. At this time, the float 210 sinks and is located at the non-detection position. Therefore, the sensor main body 220 does not output an electrical signal.

[0073] Next, for example, when the clogging of the connection flow path FR2 is resolved and the pressure applied to the liquid L in the flow path 170 becomes less than the biasing force, the valve body 410 is pressed against the lower end surface (lower end surface 152a) of the valve chamber R3 by the biasing force, and the relief valve 400 closes. As a result, the flow of the liquid L returns to the state shown in FIG. 5(b).

[0074] In this way, by arranging the float chamber R1, the valve chamber R3, the flow path 170, and the sensor mounting portion 180 in one flow path block body 100, the functions of the discharge sensor 200 and the relief valve 400 are integrated into one sensor unit 10. As a result, the discharge sensor 200 and the relief valve 400 are compactly arranged within one flow path block body 100 while ensuring their respective functions.

[0075] ● Summary (1) According to the embodiment described above, the sensor unit 10 includes a flow path block body 100, a discharge sensor 200, and a relief valve 400. The flow path block body 100 encloses a flow path 170 through which the liquid L flows. The discharge sensor 200 acquires liquid information of the liquid L flowing through the flow path 170. The relief valve 400 opens and closes according to the pressure applied to the liquid L flowing through the flow path 170. The flow path 170 includes a sensor flow path 173 that guides the liquid L to the discharge sensor 200, a relief flow path 174 that guides the liquid L to the relief valve 400, and an introduction flow path 171 that guides the liquid L discharged from the metering pump P to the sensor flow path 173 and the relief flow path 174. A part of each of the discharge sensor 200 and the relief valve 400 is mounted within the flow path block body 100. According to this configuration, the functions of the discharge sensor 200 and the relief valve 400 are integrated into one flow path block body 100. As a result, the sensor unit 10 can compactly arrange both members while ensuring the respective functions of the discharge sensor 200 and the relief valve 400.

[0076] Also, according to the embodiment described above, the flow path block body 100 includes a valve chamber R3 that communicates with the relief flow path 174 and houses the valve body 410 and the biasing member 420. According to this configuration, the valve body 410 and the biasing member 420 included in the relief valve 400 are housed (mounted) within the flow path block body 100. As a result, the flow path block body 100 functions as a housing for the relief valve 400. That is, the relief valve 400 is integrated with the flow path block body 100. Therefore, the sensor unit 10 can compactly arrange both members while ensuring the respective functions of the discharge sensor 200 and the relief valve 400.

[0077] Furthermore, according to the embodiment described above, the flow path block body 100 includes a float chamber R1 that communicates with the sensor flow path 173 and houses the float 210. According to this configuration, the float 210 included in the discharge sensor 200 is housed (attached) within the flow path block body 100. As a result, the flow path block body 100 functions as a housing of the discharge sensor 200 (flow meter). That is, the portion of the discharge sensor 200 that contacts the liquid L is integrated with the flow path block body 100. Therefore, the sensor unit 10 can arrange both members compactly while ensuring the respective functions of the discharge sensor 200 and the relief valve 400.

[0078] Moreover, according to the embodiment described above, the introduction flow path 171 and the relief flow path 174 are arranged on the same virtual straight line C1. According to this configuration, the liquid L is guided to the relief valve 400 without bending even once in the flow path 170. Therefore, the pressure loss from the flow path 170 to the liquid L guided to the relief valve 400 is suppressed as compared with the case where the flow path is bent. As a result, the increase and decrease of the pressure applied to the liquid L flowing through the flow path 170 are efficiently transmitted to the relief valve 400. That is, the relief valve 400 operates (opens and closes) quickly and appropriately. Therefore, the accuracy of the opening and closing timing of the relief valve 400 with respect to the increase and decrease of the pressure applied to the liquid L is improved. Therefore, the influence on the flow path 170 and the connection flow path FR2 due to the increase in the pressure applied to the liquid L is reduced.

[0079] Furthermore, according to the embodiments described above, the inner diameter of the relief flow path 174 is larger than the inner diameters of the introduction flow path 171 and the sensor flow path 173, respectively. Generally, the pressure loss (frictional loss) of a liquid flowing through a pipe body is inversely proportional to the inner diameter of the pipe body. Therefore, according to this configuration, in the flow path 170, the liquid L is more likely to flow into the relief flow path 174 than into the sensor flow path 173. Thus, when the relief valve 400 opens, the liquid L is less likely (or does not flow) to flow toward the sensor flow path 173, and the floating and sinking of the float 210 are suppressed. As a result, when the relief valve 400 is open, the discharge sensor 200 does not detect the flow of the liquid L. As a result, the user can grasp the clogging on the discharge side with higher accuracy.

[0080] Furthermore, according to the embodiments described above, the length of the sensor flow path 173 is longer than the length of the relief flow path 174. According to this configuration, the pressure applied to the liquid L from the metering pump P is transmitted to the valve body 410 before reaching the float 210. Also, generally, the pressure loss (frictional loss) of a liquid flowing through a pipe body is proportional to the length of the pipe body. Therefore, according to this configuration, in the flow path 170, the liquid L is more likely to flow into the relief flow path 174 than into the sensor flow path 173. Thus, when the relief valve 400 opens, the liquid L is less likely (or does not flow) to flow into the float chamber R1, and the floating and sinking of the float 210 are suppressed. As a result, when the relief valve 400 is open, the discharge sensor 200 does not detect the flow of the liquid L. As a result, the user can grasp the clogging on the discharge side with higher accuracy.

[0081] Furthermore, according to the embodiments described above, the center line of the sensor channel 173 is orthogonal to the center line of the relief channel 174. Here, the channel 170 is formed in the channel block body 100 by machining using, for example, a drill. Therefore, the channel 170 is composed of a combination of a plurality of linear holes. Thus, if the sensor channel 173 is arranged inclined with respect to the relief channel 174, either the sensor channel 173 or the air vent channel 175 extends obliquely downward from the branch portion 172. Therefore, the portion extending obliquely downward can become a liquid pool or an extra machining hole (waste hole). However, according to this configuration, when either the sensor channel 173 or the relief channel 174 is arranged along the vertical direction, the other is arranged along the horizontal direction. Therefore, no liquid pool is formed in the sensor channel 173 and the relief channel 174, and it is difficult to form unnecessary machining holes in the channel block body 100. Therefore, the sensor unit 10 can efficiently form (arrange) the channel 170 in the channel block body 100. Therefore, the sensor unit 10 can arrange the channel 170, the discharge sensor 200, and the relief valve 400 in one channel block body 100 while suppressing an increase in the volume of the channel block body 100. As a result, the sensor unit 10 can arrange both members compactly while ensuring the respective functions of the discharge sensor 200 and the relief valve 400.

[0082] Furthermore, according to the embodiments described above, the discharge sensor 200 is arranged side by side with the relief valve 400 in a direction (left - right direction) orthogonal to the opening and closing direction (up - down direction) of the relief valve 400. According to this configuration, in the up - down direction, the length of the flow path block body 100 can be determined based on the length of either the discharge sensor 200 or the relief valve 400. Also, the float chamber R1 extends along the up - down direction, and the opening and closing direction of the relief valve 400 also extends along the up - down direction. Therefore, even when the discharge sensor 200 and the relief valve 400 are arranged side by side in the left - right direction, the length of the flow path block body 100 can be made shorter compared to the case where a discharge sensor and a relief valve that are separate from each other are arranged side by side. Thus, the sensor unit 10 can arrange both members compactly while ensuring the respective functions of the discharge sensor 200 and the relief valve 400.

[0083] Furthermore, according to the embodiments described above, the flow path block body 100 includes a sensor attachment portion 180 to which the sensor main body 220 is attached. The sensor attachment portion 180 is arranged on the left surface 100d of the flow path block body 100 and is constituted by a recess that is recessed toward the float chamber R1 side. According to this configuration, the sensor main body 220 does not protrude from the flow path block body 100. Also, the distance between the sensor main body 220 and the float 210 is shortened. Therefore, the sensitivity of the sensor main body 220 to detect the floating (movement) of the float 210 is improved.

[0084] Furthermore, according to the embodiments described above, the flow path block body 100 is made of a transparent synthetic resin. According to this configuration, the user can visually observe the liquid L in the flow path 170 enclosed in the flow path block body 100. As a result, the user can immediately grasp the behavior of the float 210 and the presence or absence of air bubbles in the flow path 170.

[0085] Furthermore, according to the embodiment described above, the retainer 430 is screwed into the opening of the valve chamber R3 of the flow path block body 100. According to this configuration, at least a part of the retainer 430 is attached inside the flow path block body 100. As a result, the sensor unit 10 can arrange the discharge sensor 200 and the relief valve 400 more compactly. Also, according to this configuration, the biasing force of the biasing member 420 can be adjusted according to the screwing amount of the retainer 430.

[0086] ●Sensor unit (2)● Next, another embodiment of the sensor unit according to the present invention (hereinafter referred to as "second embodiment") will be described centering on the parts different from the embodiment described above (hereinafter referred to as "first embodiment"). In the second embodiment, the configuration of the flow path block body is different from that of the first embodiment. In the following description, elements common to the first embodiment and elements that differ only in posture (position and orientation) from the first embodiment are given the same reference numerals, and part or all of the description thereof is omitted.

[0087] ●Configuration of the sensor unit (2) FIG. 6 is a cross-sectional view in a virtual plane (XZ plane) showing another embodiment (second embodiment) of the sensor unit according to the present invention. FIG. 7 is an exploded cross-sectional view in the virtual plane of the sensor unit of FIG. 6. FIGS. 6 and 7 show together three joints 31 to 33 attached to the sensor unit 10A. Also, FIG. 6 shows the discharge flow path FR1, the connection flow path FR2, and the external discharge flow path FR3 each by a broken line.

[0088] The sensor unit 10A acquires liquid information (in this embodiment, the presence or absence of the flow of the liquid L) of the liquid L discharged from the metering pump P. The sensor unit 10A includes a flow path block body 100A, a discharge sensor 200, a stopper 300, and a relief valve 400.

[0089] The flow path block body 100A defines a flow path 170A described later and also functions as a housing for the discharge sensor 200 and the relief valve 400. The shape of the flow path block body 100A is a substantially rectangular parallelepiped shape that is flat in the front-rear direction. The flow path block body 100A is made of a transparent synthetic resin such as PMMA, for example. The flow path block body 100A includes a first joint attachment portion 110, a second joint attachment portion 120, a third joint attachment portion 130, a float accommodation portion 140, a relief valve attachment portion 150A, a flow path 170A, and a sensor attachment portion 180.

[0090] The first joint attachment portion 110 is disposed in the left half of the lower surface 100Ac of the flow path block body 100A. The first joint attachment portion 110 includes a fitting hole 110a.

[0091] The second joint attachment portion 120 is disposed in the left half of the upper surface 100Aa of the flow path block body 100A and is open upward. The second joint attachment portion 120 is disposed above the fitting hole 110a. In a top view, the center line of the second joint attachment portion 120 overlaps with the center line of the first joint attachment portion 110.

[0092] The third joint attachment portion 130 is a vertically extending, vertically flattened cylindrical hole. The third joint attachment portion 130 is disposed in the right half of the upper surface 100Aa of the flow path block body 100A and is open upward. As a result, in the left-right direction, the third joint attachment portion 130 is disposed side by side with the second joint attachment portion 120 at the upper end portion within the flow path block body 100A.

[0093] The float accommodation portion 140 is disposed below the second joint attachment portion 120 within the flow path block body 100A. In a top view, the center line of the float accommodation portion 140 overlaps with the center line of the second joint attachment portion 120. The large-diameter portion 141 of the float accommodation portion 140 defines a stopper chamber R2, and the small-diameter portion 142 of the float accommodation portion 140 defines a float chamber R1.

[0094] The relief valve mounting portion 150A is the portion of the flow path block body 100A where the relief valve 400 is mounted. The relief valve mounting portion 150A is a cylindrical hole along the lower left and right direction. The relief valve mounting portion 150A is disposed in the lower half of the right surface 100Ab of the flow path block body 100A and opens toward the right. The relief valve mounting portion 150A is disposed below the third joint mounting portion 130 within the flow path block body 100A. A part of the inner peripheral surface 151Aa of the right half portion 151A of the relief valve mounting portion 150A is a female thread surface corresponding to the male thread surface (outer peripheral surface 431a) of the retainer 430. The left half portion 152A of the relief valve mounting portion 150A defines a valve chamber R3A that houses the valve body 410 and the biasing member 420. The left end surface 152Aa of the relief valve mounting portion 150A is an inclined surface in the shape of an inverted frustum of a cone.

[0095] The flow path 170A guides the liquid L to the float chamber R1 and the valve chamber R3A in the flow path block body 100A. The flow path 170A is disposed within the flow path block body 100A. The flow path 170A includes an introduction flow path 171A, a branch portion 172A, a sensor flow path 173A, a relief flow path 174A, and a discharge flow path 176A.

[0096] The introduction flow path 171A guides the liquid L from the discharge flow path FR1 to the sensor flow path 173A and the relief flow path 174A. The introduction flow path 171A is a cylindrical hole along the vertical direction. The lower end of the introduction flow path 171A is connected to the upper end of the fitting hole 110a of the first joint mounting portion 110. The upper end of the introduction flow path 171A is connected to the branch portion 172A. That is, the introduction flow path 171A communicates with the fitting hole 110a and the branch portion 172A. That is, the fitting hole 110a communicates with the branch portion 172A via the introduction flow path 171A.

[0097] The branch portion 172A is a three-way branch point connected to the introduction flow path 171A, the sensor flow path 173A, and the relief flow path 174A respectively. That is, the introduction flow path 171A, the sensor flow path 173A, and the relief flow path 174A communicate with each other via the branch portion 172A.

[0098] The sensor flow path 173A guides the liquid L from the introduction flow path 171A to the float chamber R1. The sensor flow path 173A is a columnar hole along the vertical direction. The lower end of the sensor flow path 173A is connected to the branch portion 172A. The upper end of the sensor flow path 173A is connected to the lower end of the float chamber R1. That is, the sensor flow path 173A communicates with the branch portion 172A and the float chamber R1. That is, the branch portion 172A communicates with the float chamber R1 via the sensor flow path 173A.

[0099] The relief flow path 174A guides the liquid L from the introduction flow path 171A to the valve chamber R3A. The relief flow path 174A is a columnar hole along the horizontal direction. The right end of the relief flow path 174A is connected to the left end of the valve chamber R3A. The left end of the relief flow path 174A is connected to the branch portion 172A. That is, the relief flow path 174A communicates with the branch portion 172A and the valve chamber R3A. That is, the branch portion 172A communicates with the valve chamber R3A via the relief flow path 174A.

[0100] The discharge flow path 176A guides the liquid L from the valve chamber R3A to the third joint mounting portion 130. The discharge flow path 176A is a columnar hole. The upper end of the discharge flow path 176A is connected to the lower end of the third joint mounting portion 130. The lower end of the discharge flow path 176A extends obliquely downward to the left from the third joint mounting portion 130 and is connected to the upper end (inner peripheral surface) of the valve chamber R3A. That is, the discharge flow path 176A communicates with the valve chamber R3A and the third joint mounting portion 130. That is, the valve chamber R3A communicates with the third joint mounting portion 130 via the discharge flow path 176A.

[0101] In the flow path block body 100A, the center lines of the introduction flow path 171A, the sensor flow path 173A, the relief flow path 174A, and the discharge flow path 176A are arranged on a common virtual plane (XZ plane) together with the center lines of the insertion hole 110a, the second joint mounting portion 120, the third joint mounting portion 130, the float housing portion 140, and the relief valve mounting portion 150A, respectively. In other words, the center lines of the introduction flow path 171A, the sensor flow path 173A, the relief flow path 174A, the discharge flow path 176A, the insertion hole 110a, the second joint mounting portion 120, the third joint mounting portion 130, the float housing portion 140, and the relief valve mounting portion 150 are arranged without deviation in the front-rear direction. As a result, even when these elements are arranged in the flow path block body 100A, the thickness of the flow path block body 100A can be reduced. The center lines of the insertion hole 110a, the introduction flow path 171A, the sensor flow path 173A, the float housing portion 140, and the second joint mounting portion 120 are arranged on the same virtual straight line C1A. The center lines of the relief flow path 174A and the relief valve mounting portion 150A are arranged on the same virtual straight line C2A. The center line of the relief flow path 174A is orthogonal to the center lines of the introduction flow path 171A and the sensor flow path 173A, respectively. The virtual straight line C1A is parallel to the vertical direction. The virtual straight line C2A is parallel to the left-right direction and is orthogonal to the virtual straight line C1A.

[0102] The length of the introduction flow path 171A is longer than the length of the relief flow path 174A (for example, about 6 times). The length of the sensor flow path 173A is longer than the length of the relief flow path 174A (for example, about 2 times). The length of the introduction flow path 171A is longer than the length of the sensor flow path 173A (for example, about 3 times). That is, in a state where the relief valve 400 is closed, the length of the relief flow path 174A is the shortest among the flow paths 170A through which the liquid L flows. Therefore, when the pressure of the liquid L flowing through the flow path 170A increases or decreases, the increase or decrease in pressure is quickly transmitted to the valve body 410. As a result, the relief valve 400 operates (opens and closes) quickly and appropriately, and the influence on the introduction flow path 171A and the sensor flow path 173A due to the increase in the pressure applied to the liquid L is reduced.

[0103] Among the inner diameters of the flow path 170A, the inner diameter of the introduction flow path 171A is the same as the inner diameter of the sensor flow path 173A. The inner diameter of the relief flow path 174A is larger than the inner diameters of the introduction flow path 171A and the sensor flow path 173A, respectively. The inner diameter of the relief flow path 174A is the same as the inner diameter of the discharge flow path 176A.

[0104] The sensor mounting portion 180 is disposed in the lower half of the left surface 100Ad of the flow path block body 100A. The upper half of the sensor mounting portion 180 is disposed to the left of the lower half of the float accommodating portion 140. The lower half of the sensor mounting portion 180 is disposed to the left of the upper half of the introduction flow path 171A, the branch portion 172A, and the sensor flow path 173A, respectively. In the vertical direction, the sensor mounting portion 180 has a length such that when the float 210 is settled, the sensor body 220 can be disposed on the side of the magnet 212. The sensor mounting portion 180 includes two female screw holes 180a (one is not shown; the same applies hereinafter).

[0105] The female screw holes 180a extend forward and backward of the branch portion 172A, respectively.

[0106] The discharge sensor 200 includes a float 210, a sensor body 220, a cable 230, a cover 240, and two mounting screws 250 (see also FIG. 2). The float 210 is accommodated in the float chamber R1. The sensor body 220 is attached to the sensor mounting portion 180.

[0107] The stopper 300 is accommodated in the stopper chamber R2.

[0108] The relief valve 400 includes a valve body 410, a biasing member 420, and a retainer 430.

[0109] The biasing member 420 biases the valve body 410 in the direction in which the valve body 410 closes (leftward).

[0110] The retainer 430 includes a columnar fixing portion 431 and a shaft portion 432. The outer peripheral surface 431a of the left half portion of the fixing portion 431 is a male thread surface corresponding to the female thread surface of the right half portion 151A of the relief valve mounting portion 150A. The shaft portion 432 protrudes leftward from the left surface of the fixing portion 431.

[0111] The valve body 410 is accommodated in the valve chamber R3A with the conical surface facing leftward. The biasing member 420 is accommodated in the valve chamber R3A and is disposed to the right of the valve body 410. The retainer 430 is screwed into the right half portion 151A of the relief valve mounting portion 150A. As a result, the biasing member 420 is compressed leftward by the retainer 430 and biases the valve body 410 leftward with a predetermined biasing force.

[0112] In the flow path 170A, the sensor flow path 173A and the relief flow path 174A are connected in parallel to the introduction flow path 171A. In the left - right direction, the lower end of the float chamber R1 is disposed to the left of the upper end of the valve chamber R3A. The sensor main body 220 is disposed to the left of the lower end of the float chamber R1. The center line of the valve chamber R3A is directed toward the lower half portion of the sensor mounting portion 180. Therefore, the discharge sensor 200 is disposed side by side with the relief valve 400 in the left - right direction. As a result, in the sensor unit 10A, the discharge sensor 200 and the relief valve 400 are disposed compactly.

[0113] Also, the first joint mounting portion 110 protrudes downward from the lower surface 100Ac of the flow path block body 100A. The second joint mounting portion 120 and the third joint mounting portion 130 are arranged side by side on the upper surface 100Aa of the flow path block body 100A in the left - right direction. As a result, the joints 31 - 33 protrude only in the vertical direction of the flow path block body 100A. That is, in the sensor unit 10A, the joints 31 - 33 do not protrude in the left - right direction of the flow path block body 100A. As a result, the sensor unit 10A can be disposed in a space smaller in the left - right direction than the sensor unit 10 in the first embodiment. Also, the shape of the flow path block body 100A can be formed into a horizontally long shape that is longer in the left - right direction than the flow path block body 100 in the first embodiment.

[0114] ●Operation of the sensor unit (2) Next, with reference to FIGS. 6 to 8, the operation of the sensor unit 10A will be described.

[0115] FIG. 8 is a schematic diagram of the sensor unit 10A connected to the metering pump P. FIG. 8(a) shows a state where the metering pump P is not operating, FIG. 8(b) shows a state where the metering pump P is operating, and FIG. 8(c) shows a state where a pressure equal to or greater than the biasing force is applied to the liquid L in the flow path 170A in the state of FIG. 8(b). In this figure, the portions through which the liquid L is flowing in each of the flow paths 170A, FR1 to FR3 are indicated by thick solid lines.

[0116] First, the operation of the sensor unit 10A in a state where the metering pump P is not operating is the same as that in the first embodiment. That is, the float 210 is located at the non-detection position, and the sensor main body 220 does not output an electric signal.

[0117] Next, the operation of the sensor unit 10A in a state where the metering pump P is operating is also the same as that in the first embodiment. That is, the relief valve 400 is closed, and the sensor main body 220 outputs an electric signal. At this time, the sensor unit 10A guides the liquid L to the joint 32 (connection flow path FR2) through the introduction flow path 171A, the branch portion 172A, the sensor flow path 173A, the float chamber R1, and the stopper chamber R2.

[0118] Next, in the state shown in FIG. 8(b), for example, when the connection flow path FR2 is clogged, the pressure applied to the liquid L in the flow path 170A increases due to the liquid L discharged from the metering pump P. Then, when the metering pump P is operating and a pressure equal to or greater than the biasing force is applied to the liquid L in the flow path 170A, as shown in FIG. 8(c), the valve body 410 moves to the right against the biasing force, and the relief valve 400 opens. As a result, the sensor unit 10A guides the liquid L to the joint 33 (external discharge flow path FR3) through the introduction flow path 171A, the branch portion 172A, the relief flow path 174A, the valve chamber R3A, and the discharge flow path 176A.

[0119] As described above, the sensor flow path 173A and the relief flow path 174A are connected in parallel to the introduction flow path 171A. The length of the sensor flow path 173A is longer than the length of the relief flow path 174A. Therefore, the pressure applied to the liquid L from the metering pump P is transmitted to the valve body 410 before reaching the float 210. Also, as described above, the liquid L is more likely to flow into the relief flow path 174A than into the sensor flow path 173A. On the other hand, as described above, the center lines of the float chamber R1, the introduction flow path 171A, and the sensor flow path 173A are arranged on the same virtual straight line C1A. That is, the shape of the portion of the flow path 170A from the introduction flow path 171A to the float chamber R1 is linear. Therefore, the pressure applied to the liquid L from the metering pump P can also be transmitted to the float 210. That is, since a flow of the liquid L can occur in the float chamber R1, the float 210 can float and sink. Here, the pressure applied to the liquid L increases according to the discharge amount (liquid feed amount) of the metering pump P. Therefore, in the second embodiment, the discharge amount of the metering pump P is limited to an amount that can suppress the movement of the float 210 to a position lower than the detection position.

[0120] Next, for example, when the blockage of the connection flow path FR2 is resolved and the pressure applied to the liquid L in the flow path 170A becomes less than the biasing force, the valve body 410 is pressed against the left end surface (left end surface 152Aa) of the valve chamber R3A by the biasing force, and the relief valve 400 closes. As a result, the flow of the liquid L returns to the state shown in FIG. 8(b).

[0121] In this way, since the float chamber R1, the valve chamber R3A, the flow path 170A, and the sensor mounting portion 180 are arranged in one flow path block body 100A, the functions of the discharge sensor 200 and the relief valve 400 are integrated into one sensor unit 10A, and the discharge sensor 200 and the relief valve 400 are arranged compactly.

[0122] ● Summary (2) According to the embodiments described above, the sensor unit 10A includes a flow path block body 100A, a discharge sensor 200, and a relief valve 400. According to this configuration, similar to the first embodiment, the functions of the discharge sensor 200 and the relief valve 400 are aggregated in one flow path block body 100A. As a result, the sensor unit 10A can compactly arrange both members while ensuring the functions of the discharge sensor 200 and the relief valve 400.

[0123] Also, according to the embodiments described above, the flow path block body 100A includes a valve chamber R3A that communicates with the relief flow path 174A and houses a valve body 410 and a biasing member 420. According to this configuration, similar to the first embodiment, the flow path block body 100A functions as a housing for the relief valve 400. That is, the relief valve 400 is integrated with the flow path block body 100A. Therefore, the sensor unit 10A can compactly arrange both members while ensuring the functions of the discharge sensor 200 and the relief valve 400.

[0124] Furthermore, according to the embodiments described above, the flow path block body 100A includes a float chamber R1 that communicates with the sensor flow path 173A and houses a float 210. According to this configuration, similar to the first embodiment, the flow path block body 100A functions as a housing for the discharge sensor 200 (flow meter). That is, the portion of the discharge sensor 200 that contacts the liquid L is integrated with the flow path block body 100A. Therefore, the sensor unit 10A can compactly arrange both members while ensuring the functions of the discharge sensor 200 and the relief valve 400.

[0125] Furthermore, according to the embodiment described above, the flow path 170A includes an introduction flow path 171A. The introduction flow path 171A communicates with the sensor flow path 173A and the relief flow path 174A, and guides the liquid L discharged from the metering pump P to the sensor flow path 173A and the relief flow path 174A. The introduction flow path 171A and the sensor flow path 173A are arranged on the same virtual straight line C1A. According to this configuration, the liquid L is guided to the float chamber R1 without bending even once in the flow path 170A. Therefore, the pressure loss from the flow path 170A to the liquid L guided to the float chamber R1 is suppressed as compared with the case where the flow path is bent. As a result, the flow of the liquid L from the introduction flow path 171A to the float chamber R1 is efficiently transmitted to the float 210. Therefore, the accuracy of the timing of the floating and sinking of the float 210 with respect to the flow of the liquid L is improved.

[0126] Furthermore, according to the embodiment described above, the inner diameter of the relief flow path 174A is larger than the inner diameters of the introduction flow path 171A and the sensor flow path 173A, respectively. According to this configuration, as in the first embodiment, when the relief valve 400 is open, the floating and sinking of the float 210 are suppressed. As a result, when the relief valve 400 is open, the discharge sensor 200 does not detect the flow of the liquid L. As a result, the user can grasp the clogging on the discharge side with higher accuracy.

[0127] Furthermore, according to the embodiment described above, the length of the sensor flow path 173A is longer than the length of the relief flow path 174A. According to this configuration, as in the first embodiment, when the relief valve 400 is open, the discharge sensor 200 does not detect the flow of the liquid L. As a result, the user can grasp the clogging on the discharge side with higher accuracy.

[0128] Furthermore, according to the embodiment described above, the center line of the sensor channel 173A is orthogonal to the center line of the relief channel 174A. According to this configuration, similar to the first embodiment, no liquid pool is formed in the sensor channel 173A and the relief channel 174A, and it is difficult to form unnecessary processing holes in the channel block body 100A. Therefore, the sensor unit 10A can efficiently form (arrange) the channel 170A in the channel block body 100A. Therefore, the sensor unit 10A can arrange the channel 170A, the discharge sensor 200, and the relief valve 400 in one channel block body 100A while suppressing an increase in the volume of the channel block body 100A. As a result, the sensor unit 10A can arrange both members compactly while ensuring the respective functions of the discharge sensor 200 and the relief valve 400.

[0129] Furthermore, according to the embodiment described above, the discharge sensor 200 is arranged side by side with the relief valve 400 in the opening / closing direction (vertical direction) of the relief valve 400. According to this configuration, in the vertical direction, the length of the channel block body 100A can be determined based on the length of either the discharge sensor 200 or the relief valve 400. Also, in the horizontal direction, even when the discharge sensor 200 and the relief valve 400 are arranged side by side, the length of the channel block body 100A can be made shorter compared to the case where the discharge sensor and the relief valve, which are separate from each other, are arranged side by side. Therefore, the sensor unit 10A can arrange both members compactly while ensuring the respective functions of the discharge sensor 200 and the relief valve 400.

[0130] Furthermore, according to the embodiment described above, the channel block body 100A includes a sensor mounting portion 180 to which the sensor main body 220 is attached. According to this configuration, similar to the first embodiment, the sensor main body 220 does not protrude from the channel block body 100A. Also, the sensitivity of the sensor main body 220 to detect the floating (movement) of the float 210 is improved.

[0131] Furthermore, according to the embodiments described above, the flow path block body 100A is made of a transparent synthetic resin. According to this configuration, the user can visually observe the liquid L in the flow path 170A included in the flow path block body 100A.

[0132] Furthermore, according to the embodiments described above, the retainer 430 is fitted into the flow path block body 100A. According to this configuration, similarly to the first embodiment, the sensor unit 10A can arrange the discharge sensor 200 and the relief valve 400 more compactly.

[0133] ●Other Embodiment Examples● In addition, in each of the embodiments described above, the liquid in the present invention is not limited to an aqueous solution of sodium hypochlorite. That is, for example, the liquid in the present invention may be water, or may be other chemical solutions.

[0134] Also, in each of the embodiments described above, the liquid information in the present invention is not limited to the flow of the liquid. That is, for example, the liquid information in the present invention may be the flow rate of the liquid. In this case, the discharge sensor in the present invention may be a flow meter. Here, the discharge sensor in the present invention can also function as a flow meter if the flow rate per one reciprocating motion of the diaphragm is known.

[0135] Furthermore, in each of the embodiments described above, the shape of the flow path block body in the present invention is not limited to a rectangular parallelepiped shape. That is, for example, the shape of the flow path block body in the present invention may be an elliptical column shape or a cylindrical shape.

[0136] Furthermore, in each of the embodiments described above, the flow path block body in the present invention does not have to be made of a transparent material. That is, for example, the flow path block body in the present invention may be made of a translucent material, or may be made of an opaque material.

[0137] Furthermore, in each of the embodiments described above, the flow path block body in the present invention may be made of a transparent glass material.

[0138] Furthermore, in each of the embodiments described above, the first joint attachment portion in the present invention may protrude toward the side of the flow path block body, or may not protrude from the flow path block body.

[0139] Furthermore, in each of the embodiments described above, the discharge sensor in the present invention may not include a float. That is, for example, the discharge sensor in the present invention may be an ultrasonic or electromagnetic flow meter. In this case, the flow path block body in the present invention may include an attachment portion for an ultrasonic transmitter / receiver, a coil attachment portion, or an electrode attachment portion according to the detection method of the discharge sensor.

[0140] Furthermore, in each of the embodiments described above, the discharge sensor in the present invention is not limited to a flow meter. That is, for example, the discharge sensor in the present invention may be a pressure sensor, a thermometer, or a conductivity meter. In this case, an electrode may be disposed in the float chamber (for example, through a hole communicating with the flow chamber) in the flow path block body in the present invention instead of a float, for example.

[0141] Furthermore, in the first embodiment described above, the sensor unit according to the present invention may not include an air vent valve. That is, for example, the flow path block body in the present invention may not include an air vent valve attachment portion. In this case, the end of the air vent flow path in the present invention is blocked with, for example, an adhesive or the like.

[0142] Furthermore, in each of the embodiments described above, the inner diameters of the flow paths (introduction flow path, sensor flow path, relief flow path, and discharge flow path) in the present invention may be the same. That is, for example, the inner diameter of the relief flow path in the present invention may be the same as the inner diameters of the introduction flow path and the sensor flow path, respectively.

[0143] Furthermore, in each of the embodiments described above, the center line of the sensor flow path in the present invention may be connected to the center line of the relief flow path in an inclined state. That is, for example, in the first embodiment, the first sensor flow path in the present invention may extend obliquely upward to the left from the branch point. In this case, the air vent flow path in the present invention extends obliquely downward to the right from the branch point.

[0144] Furthermore, in each of the embodiments described above, the sensor flow path and the relief flow path in the present invention may not be arranged on the same virtual straight line as the introduction flow path. That is, for example, each of the sensor flow path and the relief flow path in the present invention may extend in the left and right directions respectively from the branch point.

[0145] Furthermore, in each of the embodiments described above, if the float does not move to the detection position while the relief valve is open, the length of the sensor flow path in the present invention may be less than or equal to the length of the relief flow path.

[0146] Furthermore, in each of the embodiments described above, the sensor mounting portion in the present invention may have a size such that the sensor body can be arranged on the side of the float (magnet) when the float is floating. That is, for example, in the vertical direction, the upper end of the sensor mounting portion in the present invention may extend to the side of the stopper chamber.

[0147] Furthermore, in each of the embodiments described above, the sensor body in the present invention may be arranged on the side of the float (magnet) when the float is floating. In this case, the sensor body in the present invention may output an electrical signal when no liquid is flowing in the float chamber.

[0148] Furthermore, in each of the embodiments described above, the discharge sensor according to the present invention may include a float biasing member (e.g., a coil spring) that biases the float in the reverse direction of the liquid flow. In this case, the float biasing member is housed in the float chamber and abuts against the float and the stopper. Also, for example, the discharge sensor according to the present invention may include another magnet that attracts and repels the magnet of the float. In this case, the other magnet is disposed at or near the end of the float chamber. According to this configuration, the orientation of the float chamber is not limited to the vertical direction, and the degree of freedom in arranging the float chamber is improved.

[0149] Furthermore, in each of the embodiments described above, the sensor unit according to the present invention may not include a stopper. In this case, for example, the joint in the present invention may function as a stopper.

[0150] Furthermore, in each of the embodiments described above, the sensor unit according to the present invention may include each joint.

[0151] Furthermore, in each of the embodiments described above, the discharge sensor and the relief valve in the present invention may be connected in series. That is, for example, the sensor flow path in the present invention may communicate with the valve chamber.

[0152] FIG. 9 is a cross-sectional view in a virtual plane (XZ plane) showing a modified example of an embodiment of the sensor unit according to the present invention.

[0153] In the sensor unit 10B in the modification example, the discharge sensor 200 and the relief valve 400 are arranged in series. Specifically, the third joint mounting portion 130 is arranged in the vicinity of the first joint mounting portion 110. The introduction flow path 171B is connected to the third joint mounting portion 130. The relief valve mounting portion 150B is arranged on the side of the third joint mounting portion 130. The relief flow path 174B is connected to the third joint mounting portion 130 and the relief valve mounting portion 150B. The center lines of the third joint mounting portion 130, the relief flow path 174B, and the relief valve mounting portion 150B are arranged on the same virtual straight line C1B along the left - right direction. The float housing portion 140 is arranged above the valve chamber R3B. The sensor flow path 173B is connected to the valve chamber R3B. As a result, the introduction flow path 171B communicates with the relief flow path 174B via the third joint mounting portion 130. Also, the introduction flow path 171B communicates with the sensor flow path 173B via the third joint mounting portion 130, the relief flow path 174B, and the valve chamber R3B. The center lines of the float housing portion 140 and the sensor flow path 173B are arranged on the same virtual straight line C2B along the up - down direction.

[0154] When the pressure applied to the liquid L in the external discharge flow path FR3 is less than the biasing force, the relief valve 400 is closed and the liquid L is guided to the external discharge flow path FR3. On the other hand, when a pressure equal to or greater than the biasing force is applied to the liquid L in the external discharge flow path FR3, the relief valve 400 opens. When the relief valve 400 opens, the sensor unit 10B guides the liquid L to the joint 32 (connection flow path FR2) via the introduction flow path 171B, the third joint mounting portion 130, the relief flow path 174B, the valve chamber R3B, the sensor flow path 173B, and the float chamber R1. In this case, the discharge sensor 200 detects the flow of the liquid L guided from the relief valve 400. According to this configuration, the sensor unit 10B can compactly arrange both members in one flow path block body 100B while ensuring the respective functions of the discharge sensor 200 and the relief valve 400 in the up - down direction.

[0155] ● Pump device ● Next, with reference to the drawings, embodiments of the pump device according to the present invention will be described. In the following description, the pump device according to the present invention is assumed to have the sensor unit in the first embodiment. Also, in the following description, elements common to the first embodiment are denoted by the same reference numerals, and part or all of the description thereof is omitted.

[0156] ●Configuration of the pump device FIG. 10 is a cross-sectional view showing an embodiment of the pump device according to the present invention. For convenience of explanation, this figure shows a simplified illustration of a part of the pump device 1.

[0157] The pump device 1 sucks the liquid L from the outside of the pump device 1 (for example, a storage tank for the liquid L) and discharges the sucked liquid L to the sensor unit 10. The pump device 1 includes a sensor unit 10, a pump body 20, and joints 31C, 32, 33.

[0158] The sensor unit 10 is the sensor unit 10 in the first embodiment.

[0159] The pump body 20 is, for example, an electromagnetic drive type diaphragm pump. The pump body 20 includes a pump head 21 and a drive unit 22.

[0160] The pump head 21 sucks the liquid L from the outside and discharges the sucked liquid L to the sensor unit 10. The pump head 21 includes a pump chamber 21a, a diaphragm 21b, a suction part 21c, and a discharge part 21d.

[0161] The pump chamber 21a houses the diaphragm 21b.

[0162] The diaphragm 21b reciprocates in the left-right direction within the pump chamber 21a to increase or decrease the volume (pressure) within the pump chamber 21a. As a result, the liquid L is sucked from the suction part 21c into the pump chamber 21a, and the sucked liquid L is discharged from the pump chamber 21a to the discharge part 21d.

[0163] The suction part 21c guides the liquid L from the outside to the pump chamber 21a. The suction part 21c includes a suction part flow path 21c1 that communicates with the pump chamber 21a.

[0164] The discharge part 21d guides the liquid L from the pump chamber 21a to the sensor unit 10. The discharge part 21d includes a discharge part flow path 21d1 that communicates with the pump chamber 21a.

[0165] The drive part 22 reciprocates the diaphragm 21b. The drive part 22 is, for example, a known electromagnetic actuator.

[0166] The joint 31C is attached to the discharge-side end (the upper end in this embodiment) of the discharge part 21d, and connects the sensor unit 10 and the discharge part 21d. The joint 31C is, for example, a known screw plug. In this embodiment, the sensor unit 10 is directly connected to the pump head 21 via the joint 31C. As a result, the discharge part flow path 21d1 communicates with the introduction flow path 171 of the sensor unit 10 via the joint 31C. At this time, as described above, the first joint attachment part 110 protrudes downward from the lower surface 100c of the flow path block body 100. Therefore, when the sensor unit 10 is directly connected to the pump head 21, physical interference of the flow path block body 100 with respect to the pump body 20 is avoided.

[0167] ● Operation of the pump device The operation of the pump device 1 is common to the operation of the sensor unit 10 in the first embodiment. Therefore, details of the operation of the pump device 1 are omitted.

[0168] ● Summary According to the embodiment described above, the pump device 1 includes the sensor unit 10 in the first embodiment. Therefore, similar to the first embodiment, the pump device 1 can arrange the two members compactly while ensuring the functions of the discharge sensor 200 and the relief valve 400.

[0169] Further, according to the embodiment described above, the sensor unit 10 is directly connected to the pump head 21 via the joint 31C. According to this configuration, the sensor unit 10 is supported by the pump head 21 only via the joint 31C. Therefore, members such as a pedestal for supporting the sensor unit 10 become unnecessary. Further, according to this configuration, the discharge sensor 200 is arranged side by side with the relief valve 400 in the left - right direction. Therefore, even if the sensor unit 10 is directly attached to the pump head 21, compared with a conventional pump device (hereinafter referred to as "conventional device") in which the discharge sensor and the relief valve are arranged in series above the pump head, an increase in the height of the pump device 1 is suppressed. Furthermore, according to this configuration, the distance from the pump chamber 21a to the relief valve 400 can be made as short as possible. As a result, the pressure loss of the liquid L guided from the pump chamber 21a to the relief valve 400 is more suppressed compared with the first embodiment. As a result, an increase or decrease in the pressure applied to the liquid L flowing through the flow path 170 is efficiently transmitted to the relief valve 400. Therefore, the accuracy of the opening and closing timing of the relief valve 400 with respect to the pressure applied to the liquid L is improved.

[0170] ●Other Embodiment Examples● In addition, in the embodiment described above, the pump device 1 according to the present invention includes the sensor unit 10 in the first embodiment. Instead of this, the pump device according to the present invention may include the sensor unit in the second embodiment or the sensor unit in other embodiments.

[0171] Also, in the embodiments described above, the pump body in the present invention is not limited to an electromagnetic - drive type diaphragm pump. That is, for example, the pump body in the present invention may be a tube pump, a centrifugal pump, a motor - drive type diaphragm pump, a plunger pump, or a piston pump.

[0172] ●Embodiments of the Present Invention● Next, regarding the embodiments of the present invention grasped from the above - described embodiments, while using the terms and reference numerals described in each embodiment, the following will be described.

[0173] The first embodiment of the present invention is a sensor unit (for example, sensor units 10, 10A, 10B) that acquires liquid information (for example, presence or absence of flow) regarding a liquid (for example, liquid L) discharged from a pump device (for example, metering pump P, pump body 20), including a flow path block body (for example, flow path block bodies 100, 100A, 100B) that encloses a flow path (for example, flow paths 170, 170A, 170B) through which the liquid flows, a discharge sensor (for example, discharge sensor 200) that acquires the liquid information of the liquid flowing through the flow path, and a relief valve (for example, relief valve 400) that opens and closes according to the pressure applied to the liquid flowing through the flow path. The flow path includes a sensor flow path (for example, sensor flow paths 173, 173A, 173B) that guides the liquid to the discharge sensor, a relief flow path (for example, relief flow paths 174, 174A, 174B) that guides the liquid to the relief valve, and an introduction flow path (for example, introduction flow paths 171, 171A, 171B) that communicates with the sensor flow path and the relief flow path and guides the liquid discharged from the pump device to the sensor flow path and the relief flow path. Each of the discharge sensor and the relief valve is a sensor unit mounted within the flow path block body. According to this configuration, the functions of each of the discharge sensor and the relief valve are integrated into one flow path block body. As a result, the sensor unit can compactly arrange both members while ensuring the functions of the discharge sensor and the relief valve.

[0174] The second embodiment of the present invention is, in the first embodiment, the sensor unit in which the relief valve includes a valve body (for example, valve body 410) that opens and closes according to the pressure of the liquid, and a biasing member (for example, biasing member 420) that biases the valve body in a direction in which the valve body closes, and the flow path block body includes a valve chamber (for example, valve chambers R3, R3A, R3B) that communicates with the relief flow path and houses the valve body and the biasing member. According to this configuration, the relief valve is integrated with the flow path block body. Therefore, the sensor unit can arrange both members compactly while ensuring the functions of the discharge sensor and the relief valve.

[0175] In the third embodiment of the present invention, in the first or second embodiment, the discharge sensor includes a float (for example, float 210) that floats and sinks according to the flow of the liquid, and the flow path block body communicates with the sensor flow path and includes a float chamber (for example, float chamber R1) in which the float is accommodated, and is a sensor unit. According to this configuration, the portion of the discharge sensor that contacts the liquid is integrated with the flow path block body. Therefore, the sensor unit can arrange both members compactly while ensuring the functions of the discharge sensor and the relief valve.

[0176] In the fourth embodiment of the present invention, in any one of the first to third embodiments, either one of the sensor flow path or the relief flow path and the introduction flow path are arranged on the same virtual straight line (for example, virtual straight lines C1, C1A), and is a sensor unit. According to this configuration, the accuracy of the opening and closing timing of the relief valve with respect to the increase and decrease of the pressure applied to the liquid is improved.

[0177] In the fifth embodiment of the present invention, in any one of the first to fourth embodiments, the inner diameter of the relief flow path is larger than the inner diameters of the introduction flow path and the sensor flow path respectively, and is a sensor unit. According to this configuration, when the relief valve is open, the discharge sensor does not detect the flow of the liquid. In addition, the user can grasp the clogging on the discharge side with higher accuracy.

[0178] In the sixth embodiment of the present invention, in any one of the first to fifth embodiments, the length of the sensor flow path is longer than the length of the relief flow path, and is a sensor unit. According to this configuration, when the relief valve is open, the discharge sensor does not detect the flow of the liquid. In addition, the user can grasp the clogging on the discharge side with higher accuracy.

[0179] The seventh embodiment of the present invention is a sensor unit in any one of the first to sixth embodiments, wherein the center line of the sensor flow path is orthogonal to the center line of the relief flow path. According to this configuration, the sensor unit can suppress an increase in the volume of the flow path block body while arranging the flow path, the discharge sensor, and the relief valve in one flow path block body. As a result, the sensor unit can arrange both members compactly while ensuring the functions of the discharge sensor and the relief valve.

[0180] The eighth embodiment of the present invention is a sensor unit in any one of the first to seventh embodiments, wherein the discharge sensor is arranged side by side with the relief valve in the opening / closing direction of the relief valve or in a direction orthogonal to the opening / closing direction. According to this configuration, the sensor unit can arrange both members compactly while ensuring the functions of the discharge sensor and the relief valve.

[0181] The ninth embodiment of the present invention is the same as the third embodiment, wherein the discharge sensor includes a sensor body (for example, sensor body 220) that detects the flow of the liquid based on the floating and sinking of the float, the flow path block body includes a recess (for example, sensor mounting portion 180) to which the sensor body is attached, the recess is arranged on the outer surface (for example, left surfaces 100d, 100Ad) of the flow path block body, and is recessed toward the float chamber side, and is a sensor unit. According to this configuration, the sensor body does not protrude from the flow path block body. Also, the sensitivity of the sensor body to detect the floating (movement) of the float is improved.

[0182] The tenth embodiment of the present invention is a pump device (for example, pump device 1) including a pump head (for example, pump head 21) that sucks a liquid and discharges the sucked liquid, and the sensor unit according to any one of claims 1 to 9 connected to the pump head. According to this configuration, the pump device can arrange both members compactly while ensuring the functions of the discharge sensor and the relief valve.

Explanation of Signs

[0183] 1 Pump device 10 Sensor unit 100 Flow path block body 100d Left surface (outer surface) 170 Flow path 171 Introduction flow path 173 Sensor flow path 174 Relief flow path 180 Sensor mounting part (recess) 200 Discharge sensor 210 Float 220 Sensor body 400 Relief valve 410 Valve body 420 Biasing member 430 Retainer 20 Pump body 21 Pump head R1 Float chamber R3 Valve chamber C1 Virtual straight line 10A Sensor unit 100A Flow path block body 100Ad Left surface (outer surface) 170A Flow path 171A Introduction flow path 173A Sensor flow path 174A Relief flow path R3A Valve chamber C1A Virtual straight line 10B Sensor unit 100B Flow path block body 170B Flow path 171B Introduction flow path 173B Sensor flow path 174B Relief flow path R3B Valve chamber

Claims

1. A sensor unit that acquires liquid information regarding the liquid discharged from a pump device, comprising: A flow path block body that encloses a flow path through which the liquid flows; A discharge sensor that acquires the liquid information of the liquid flowing through the flow path; A relief valve that opens and closes according to the pressure applied to the liquid flowing through the flow path; And having: The flow path includes: A sensor flow path that guides the liquid to the discharge sensor; A relief flow path that guides the liquid to the relief valve; An introduction flow path that communicates with the sensor flow path and the relief flow path and guides the liquid discharged from the pump device to the sensor flow path and the relief flow path; One branch point connected to the sensor flow path, the relief flow path, and the introduction flow path; And comprising: A part of the discharge sensor and each of the relief valves are attached inside the flow path block body; The discharge sensor includes: A float that floats and sinks according to the flow of the liquid; A sensor body that detects the flow of the liquid based on the floating and sinking of the float; And comprising: The flow path block body includes: A float chamber that communicates with the sensor flow path and houses the float; And comprising: The sensor body is attached to the outer surface of the flow path block body; A part of the flow path block body that constitutes the float chamber functions as a housing of the discharge sensor in which the float is housed; Sensor unit.

2. The relief valve includes: A valve body that opens and closes according to the pressure of the liquid; A biasing member that biases the valve body in the direction in which the valve body closes; And comprising: The flow path block body includes: A valve chamber that communicates with the relief flow path and houses the valve body and the biasing member; And comprising: The sensor unit according to Claim 1.

3. Either one of the sensor flow path or the relief flow path and the introduction flow path are arranged on the same virtual straight line; The sensor unit according to Claim 1 or 2.

4. The inner diameter of the relief flow path is larger than the inner diameters of the introduction flow path and the sensor flow path respectively; The sensor unit according to any one of Claims 1 to 3.

5. The length of the sensor flow path is longer than the length of the relief flow path; The sensor unit according to any one of Claims 1 to 4.

6. The center line of the sensor flow path is orthogonal to the center line of the relief flow path; The sensor unit according to any one of Claims 1 to 5.

7. The discharge sensor is arranged side by side with the relief valve in the opening / closing direction of the relief valve or in a direction orthogonal to the opening / closing direction. The sensor unit according to any one of claims 1 to 6.

8. The flow path block body comprises a recess to which the sensor body is attached. The recess is arranged on the outer surface of the flow path block body and is recessed toward the float chamber side. The sensor unit according to claim 1.

9. A pump head that sucks in a liquid and discharges the sucked liquid, the sensor unit according to any one of claims 1 to 8 connected to the pump head, and a pump device.

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