JP7135711B2 - Load detector and clamp unit - Google Patents

Description

The present invention relates to a load detector and a clamp unit that detect a load due to pressure from an object to be measured.

Conventionally, it includes a tube through which liquid flows, a load detection sensor that detects radial displacement of the tube based on the load from the load section, and a detection section that detects clogging of the tube based on the load value of the load detection sensor. A blood purification apparatus equipped with an ironing pump is known (see Patent Document 1, for example). In addition, the apparatus of Patent Document 1 can detect negative pressure and positive pressure in the tube.

JP 2014-83091 A

When the negative pressure and positive pressure of the tube are detected by detecting the radial displacement of the tube by the load generated by the movement of the load section, static electricity is generated and the load section is sometimes charged with static electricity. If the load portion is charged with static electricity, the static electricity may cause an abnormality in the output voltage of the load detection sensor, which may result in erroneous detection of the negative pressure and positive pressure of the tube. Therefore, it is desirable to be able to prevent erroneous detection of the output voltage of the load detection sensor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a load detector clamp unit that can prevent erroneous detection of the output voltage of a load detection sensor.

The present invention includes a main body and a lid that opens and closes the main body, and when the lid is closed, detects the load due to the pressure from the measurement target portion arranged between the main body and the lid. A load detector, comprising: a load portion that can move forward and backward in the axial direction by pressure from the measurement target portion; a load detection sensor that is disposed facing the tip of the load portion and detects the load from the load portion; A load comprising a contact portion arranged in contact with the outer peripheral surface of the load portion so as not to hinder the movement of the load portion in the axial direction, and a connecting portion electrically connecting the contact portion and the ground portion. Regarding detectors.

Moreover, it is preferable that the contact portion is formed in a cylindrical shape.

Moreover, it is preferable to further include a rotation preventing portion for preventing rotation of the load portion.

The load detector is provided, the measurement target part is a tube through which liquid flows, and a clamp part that can clamp the tube placed between the main body and the lid part when the lid part is closed is provided. It further relates to a clamping unit.

ADVANTAGE OF THE INVENTION According to this invention, the clamp unit which can prevent the false detection of the output voltage of a load detection sensor can be provided.

1 is a diagram showing the overall configuration of a hemodialysis apparatus according to one embodiment of the present invention; FIG. It is a front view which shows the structure of a clamp unit. It is a figure which shows the open state of a clamp unit. It is a perspective view showing a closed state of the clamp unit. It is the perspective view which looked the clamp unit from the downward side. FIG. 5 is a cross-sectional view taken along the line AA in FIG. 4; FIG. 5 is a cross-sectional view taken along the line BB in FIG. 4; 4 is a cross-sectional view showing the configuration of a load detection unit; FIG. FIG. 4 is a perspective view showing a main configuration for preventing static electricity from being generated in a load detection unit; FIG. 10 is an exploded perspective view of the load detector shown in FIG. 9; 3 is a block diagram showing the configuration of a console; FIG. 5 is a graph showing an example of an output voltage of a force sensor and an output abnormality due to the influence of static electricity; FIG. 10 is a perspective view showing the load shaft of the first modified form, where (a) is a side view and (b) is a view of the shaft body viewed from the tip side. FIG. 10A is a perspective view showing a load shaft of a second modified form, wherein (a) is a side view and (b) is a view of the shaft main body as seen from the tip side. Fig. 10 is a perspective view showing the load shaft and the C-shaped contact portion of the third modified form, where (a) is a side view and (b) is a view of the shaft main body as seen from the tip end side; FIG. 10A is a perspective view showing a load shaft and a rod-shaped contact portion of a fourth modified form, wherein (a) is a side view and (b) is a view of the shaft body viewed from the tip end side.

A preferred embodiment of a hemodialysis apparatus including a clamp unit 60 of the present invention will be described below with reference to the drawings. The hemodialysis apparatus of the present invention purifies the blood of patients with renal failure or drug addiction, removes excess water from the blood, and replenishes the blood with water (fluid replacement) as necessary.
First, the overall configuration of the hemodialysis apparatus 1 of this embodiment will be described with reference to FIG. A hemodialysis apparatus 1 as a dialysis apparatus includes a dialyzer 10 as a hemodialyzer, a blood circuit 20, a dialysate circuit 30, a replacement fluid line 38, and a console 100. The console 100 includes an operation panel 70, a clamp unit 60, a portion of the blood circuit 20, a portion of the dialysate circuit 30, a heater 40 as a temperature control unit, a chemical pump 231, a replacement fluid pump 39, and a controller 50. It is

The dialyzer 10 includes a cylindrical container body 11 and a dialysis membrane (not shown) housed inside the container body 11. The inside of the container body 11 is separated from the blood by the dialysis membrane. It is partitioned into a channel and a dialysate side channel (both not shown). The container body 11 is formed with a blood inlet 111 and a blood outlet 112 communicating with the blood-side channel, and a dialysate inlet 113 and a dialysate outlet 114 communicating with the dialysate-side channel.

The blood circuit 20 includes an arterial line 21 , a venous line 22 , a drug line 23 and an overflow line 24 . The arterial line 21, the venous line 22, the drug line 23, and the overflow line 24 are all mainly composed of flexible tubes through which liquids can flow.

In this embodiment, the tubes constituting the arterial line 21, the venous line 22, the drug line 23, and the overflow line 24 are flexible tubes made of polyvinyl chloride (PVC), silicon (Si), or the like. It is formed. As the tube, for example, a tube having an outer diameter of 5.5 mm and an inner diameter of 3.3 mm is used. The hardness of the tube is, for example, about 50 to 85 (JIS K7215).

One end of the arterial line 21 is connected to the artery of the subject (dialysis patient), and the other end is connected to the blood inlet 111 of the dialyzer 10 . A console 100 is arranged in the middle of the arterial line 21 . A clamp unit 60 and a blood pump 212 are arranged in a portion of the console 100 through which the arterial line 21 passes. An artery-side clamp section (clamp section) 65, a load detection section 66, and an artery-side air bubble sensor (air bubble detection section) 67 are arranged in a portion of the clamp unit 60 through which the arterial line 21 passes. Details of the clamp unit 60 will be described later.

The blood pump 212 is arranged downstream of the clamp unit 60 in the arterial line 21 . The blood pump 212 pumps out blood, priming liquid, or other liquid inside the arterial line 21 by squeezing the tube forming the arterial line 21 with a roller.

One end of the venous line 22 is connected to the blood outlet 112 of the dialyzer 10, and the other end is connected to the vein of the subject (dialysis patient). A venous chamber 222 and a console 100 are arranged in the middle of the venous line 22 . A clamp unit 60 is arranged in a portion of the console 100 through which the venous line 22 passes. A vein side clamp portion 69 and a vein side bubble sensor 68 are arranged in a portion of the clamp unit 60 through which the vein side line 22 passes. Details of the clamp unit 60 will be described later.

The venous chamber 222 is positioned between the dialyzer 10 and the console 100 in the venous line 22 . The vein side chamber 222 stores a predetermined amount (eg, 20 ml) of blood.

The drug line 23 supplies drugs required during hemodialysis to the arterial line 21 . One end (proximal side) of the drug line 23 is connected to a drug pump 231 that delivers drugs, and the other end (distal side) is connected between the blood pump 212 and the dialyzer 10 in the arterial line 21 .

One end side (proximal side) of the overflow line 24 is connected to the vein side chamber 222 . The overflow line 24 discharges the physiological saline solution, air, etc. flowing through the intravenous line 22 during the priming process. An overflow clamp 241 is arranged in the overflow line 24 . Overflow clamp 241 opens and closes the flow path of overflow line 24 .

According to the blood circuit 20 described above, the blood drawn from the artery of the subject (dialysis patient) flows through the arterial line 21 by the blood pump 212 and is introduced into the blood-side channel of the dialyzer 10 . The blood introduced into the dialyzer 10 is purified by the dialysate flowing through the dialysate circuit 30, which will be described later, through the dialysis membrane. The blood purified by the dialyzer 10 flows through the venous line 22 and is returned to the subject's veins.

In the present embodiment, the dialysate circuit 30 is configured by a so-called closed capacity control type dialysate circuit 30 . The dialysate circuit 30 includes a dialysate chamber 31, a dialysate supply line 32, a dialysate inlet line 33, a dialysate outlet line 34, a drain line 35, a bypass line 36, and water removal/backfiltration. a pump 37;

The dialysate chamber 31 includes a hard container 311 capable of accommodating a certain volume (eg, 300 ml to 500 ml) of dialysate, and a soft diaphragm 312 that partitions the interior of the container 311 . The inside of the dialysate chamber 31 is partitioned by a diaphragm 312 into a sent liquid containing portion 313 and a drained liquid containing portion 314 .

The dialysate supply line 32 is connected to a dialysate supply device (not shown) at its proximal end and to the dialysate chamber 31 at its distal end. The dialysate supply line 32 supplies the dialysate to the liquid supply storage portion 313 of the dialysate chamber 31 .

The dialysate inlet line 33 connects the dialysate chamber 31 and the dialysate inlet port 113 of the dialyzer 10 , and transfers the dialysate contained in the liquid supply/accommodation portion 313 of the dialysate chamber 31 to the dialysate-side channel of the dialyzer 10 . to be introduced.

The dialysate outlet line 34 connects the dialysate outlet 114 of the dialyzer 10 and the dialysate chamber 31 , and guides the dialysate discharged from the dialyzer 10 to the waste liquid container 314 of the dialysate chamber 31 .
The drainage line 35 is connected at its proximal end to the dialysate chamber 31 and discharges the drainage of the dialysate contained in the drainage storage section 314 .

A bypass line 36 connects the dialysate outlet line 34 and the drain line 35 .
A dewatering/backfiltration pump 37 is arranged in the bypass line 36 . The water removal/backfiltration pump 37 sends the dialysate inside the bypass line 36 in a direction (water removal direction) in which it flows to the drain line 35 side and in a direction (backfiltration direction) in which it flows to the dialysate lead-out line 34 side. It consists of a liquid-driven pump.

The heater 40 heats the dialysate flowing through the dialysate circuit 30 to a predetermined temperature.

Replacement fluid line 38 is a line for directly supplying dialysate to blood circuit 20 . As shown in FIG. 1 , the upstream side of replacement fluid line 38 is connected between dialysate chamber 31 in dialysate inlet line 33 of dialysate circuit 30 and dialysate inlet 113 of dialyzer 10 . The replenisher line 38 is provided with a replenisher clamp 381 . When the downstream side of the replacement fluid line 38 is connected between the blood pump 212 and the dialyzer 10 in the arterial line 21, as shown by the solid line in FIG. 1, predilution hemofiltration dialysis is performed. Further, when the downstream side of the replacement fluid line 38 is connected to the venous chamber 222 of the venous line 22 as indicated by the dashed line in FIG. 1, post-dilution hemofiltration dialysis is performed.

The clamp unit 60 will be explained.
The clamp unit 60 is unitized and attached to the console 100 as shown in FIG. The clamp unit 60 clamps and holds the tube forming the arterial line 21 and the tube forming the venous line 22 . In the clamp unit 60, on one side in the width direction H, the tube forming the arterial line 21 is vertically arranged, and on the other side in the width direction H, the tube forming the vein line 22 is vertically arranged. is placed across.

2 to 5, the clamp unit 60 includes a unit main body 61 (main body), a lid portion 62 for opening and closing the unit main body 61, a hinge portion 63, an opening/closing lever 641, and an opening/closing engaging portion 642. , a substrate 664 (see FIG. 5), and a load detector 66 (load detector). The clamp unit 60 fixes the tube by arranging the tube between the unit main body 61 and the lid portion 62 . The clamp unit 60 presses the inner surface of the lid portion 62 against the inner surface of the unit main body 61 with the tubes forming the arterial line 21 and the tubes forming the venous line 22 arranged on the inner surface of the unit main body 61 . , the tube forming the arterial line 21 and the tube forming the venous line 22 are fixed.

The inner surface of the lid portion 62 constitutes a tube fixing portion that fixes the tube forming the artery side line 21 and the tube forming the vein side line 22 with a constant force. In the member constituting the inner surface of the lid portion 62, at least the material of the portion that presses the tube is, for example, a resin material such as ABS resin (acrylonitrile-butadiene-styrene copolymer), ASA resin (butadiene of ABS resin). polymerized acrylic rubber), synthetic resins such as polypropylene, etc. are used. As a result, the inner surface of the lid portion 62 can sufficiently hold the tube forming the arterial line 21 and the tube forming the venous line 22 with an appropriate holding force that does not crush them excessively.

As shown in FIG. 2, the hinge portion 63 is arranged at the other end of the clamp unit 60 in the width direction H when the lid portion 62 is closed, and allows the lid portion 62 to rotate relative to the unit body 61. Connecting.

The opening/closing lever 641 is provided at one end in the width direction H of the lid portion 62 when the lid portion 62 is closed. As shown in FIG. 3, the opening/closing engaging portion 642 is provided at one end in the width direction H of the inner surface of the unit main body 61 so as to be able to engage with the opening/closing lever 641 when the lid portion 62 is closed. By operating the open/close lever 641, the unit main body 61 and the lid portion 62 are opened and closed.

As shown in FIG. 3, on the inner surface of the unit main body 61, a main body side artery side tube placement portion 611 (tube placement portion) and a main body side vein side tube placement portion 612 (tube placement portion) are formed. . The body-side artery-side tube placement portion 611 and the body-side vein-side tube placement portion 612 are spaced apart in the width direction H of the unit body 61 on the inner surface of the unit body 61 and extend linearly. The body-side artery-side tube placement portion 612 is arranged closer to the hinge portion 63 in the width direction H than the body-side artery-side tube placement portion 611 .

As shown in FIG. 5, a substrate 664 is attached to the outer surface 613 (see FIG. 8) of the unit body 61. As shown in FIG. A force sensor 665 (load detection sensor) of the load detection section 66 is mounted (arranged) on the first surface 664a (see FIG. 8) of the substrate 664 on the unit main body 61 side (see FIG. 8, which will be described later).

As shown in FIG. 3, on the inner surface of the lid portion 62, when the lid portion 62 is closed, a lid-side artery-side tube placement portion 621 that is arranged to face the body-side artery-side tube placement portion 611 and a body-side tube placement portion 621 are provided. A lid-side vein-side tube placement portion 622 arranged to face the vein-side tube placement portion 612 is formed. The lid-side artery-side tube arrangement portion 621 and the lid-side vein-side tube arrangement portion 622 are arranged apart from each other in the width direction H of the lid portion 62 on the inner surface of the lid portion 62 and extend linearly. The lid-side artery-side tube placement portion 622 is arranged closer to the hinge portion 63 in the width direction H than the lid-side artery-side tube placement portion 621 .

When the lid portion 62 is closed, the tube constituting the arterial line 21 is arranged between the main body side artery side tube arrangement portion 611 and the lid side artery side tube arrangement portion 621, and the main body side vein side tube arrangement is performed. Between the portion 612 and the lid-side vein-side tube placement portion 622, a tube that constitutes the vein-side line 22 is placed.

Here, first, the configuration provided in the body-side artery-side tube placement section 611 and the cover-side artery-side tube placement section 621 will be described.
As shown in FIGS. 3 and 6, when the lid portion 62 is closed, along the main body side artery side tube placement portion 611 and the lid side artery side tube placement portion 621, the artery side upstream tube holding portion 601 and the artery side A clamp section 65, a load detection section 66, an arterial air bubble sensor 67, and an arterial downstream tube pressing section 602 are arranged. In this embodiment, the artery-side upstream tube holding portion 601, the artery-side clamping portion 65, the load detecting portion 66, the artery-side air bubble sensor 67, and the artery-side downstream tube holding portion 602 are arranged in the clamp unit 60 from the upstream side to the downstream side. They are arranged side by side in this order (from the lower side to the upper side in FIGS. 1 and 3).

The body-side artery-side tube placement portion 611 is placed on the inner surface of the unit body 61, as shown in FIG. In the body-side artery-side tube arrangement portion 611, the artery-side upstream tube holding portion is arranged in order from the upstream side to the downstream side (from the bottom side to the top side in FIG. 3) of the liquid flowing through the tube constituting the artery-side line 21. 601, the arterial side movable clamp portion 651 of the arterial side clamp portion 65, the load receiving portion 662 of the load detecting portion 66, and the ultrasonic oscillator portion 671 of the arterial side bubble sensor 67 are accommodated therein. The receiving member 672 and the receiving recess 602a of the artery-side downstream tube pressing portion 602 are arranged side by side.

The lid-side artery-side tube placement section 621 is arranged on the inner surface of the lid section 62 and arranged to face the body-side artery-side tube placement section 611 when the cover section 62 is closed. In the lid-side artery-side tube arrangement portion 621, artery-side upstream tube retainers are arranged in order from the upstream side to the downstream side (from the bottom side to the top side in FIG. 3) of the liquid flowing through the tube constituting the artery-side line 21. 601, the arterial side clamp receiving portion 652 of the arterial side clamp portion 65, the load pressing portion 663 of the load detecting portion 66, and the ultrasonic wave receiving portion 673 of the arterial side air bubble sensor 67 are housed in the arterial side. The air bubble sensor pressing member 674 and the pressing protrusion 602b of the arterial downstream tube pressing portion 602 are arranged side by side.

The pressing projection 601b of the artery-side upstream tube pressing portion 601 is arranged to face the accommodation recess 601a arranged in the unit main body 61 when the lid portion 62 is closed, and prevents the liquid flowing through the artery-side line 21 in the clamp unit 60. The tube forming the arterial line 21 is pressed on the upstream side of (lower side in FIG. 3).

The artery side clamp receiving portion 652 is arranged to face the artery side movable clamp portion 651 arranged on the unit main body 61 when the cover portion 62 is closed. The artery-side clamp receiving portion 652 and the artery-side movable clamp portion 651 constitute the artery-side clamp portion 65 and sandwich and hold the tube that constitutes the artery-side line 21 .

As shown in FIGS. 3 and 6, the artery side clamp section 65 includes an artery side movable clamp section 651 arranged in the unit main body 61 and a solenoid 653 arranged in the unit main body 61 for driving the artery side movable clamp section 651. , and an arterial side clamp receiving portion 652 arranged on the lid portion 62 . The artery-side clamp receiving portion 652 is formed to protrude from the inner surface of the lid portion 62 and extends in the width direction H. As shown in FIG.

As shown in FIG. 6, the artery-side movable clamp part 651 has a flat tip extending in the width direction H and a trapezoidal shape with a narrow width on the tip side in a cross section cut in the direction in which the tube placement part extends. be done. An output shaft 653a of a solenoid 653 is connected to the rear end of the artery-side movable clamp section 651 so as to be able to advance and retreat. The arterial movable clamp 651 sandwiches and clamps the tube forming the arterial line 21 between the distal end of the arterial movable clamp 651 and the distal end of the arterial clamp receiver 652 by advancing and retracting the output shaft 653a of the solenoid 653. Alternatively, the arterial line 21 is opened and closed.

The arterial clamp section 65 configured as described above is arranged between the unit main body 61 and the lid section 62 by the arterial movable clamp section 651 and the arterial clamp receiving section 652 during normal operation of the hemodialysis apparatus 1. The tube that constitutes the arterial line 21 is clamped.
In addition, the artery side clamp section 65 is opened and closed during the priming and blood return processes using physiological saline. The arterial side clamp section 65 advances and retreats the arterial side movable clamp section 651 to crush or open the tube constituting the arterial side line 21, and opens and closes the flow path of the arterial side line 21, thereby operating the arterial side air bubble sensor. On the upstream side of 67, the flow of liquid flowing through the inside of the tube is circulated/stopped.

The load detection unit 66 can detect the load due to the pressure from the tube forming the arterial line 21 and output it as a voltage value. That is, when the tube is blocked, the pressure inside the tube becomes positive or negative, the radial direction of the tube changes, and the load changes accordingly, which is detected as a change in voltage value. As shown in FIG. 7, the load detection section 66 has a load holding section 663, a load receiving section 662, a force sensor 665 arranged on a substrate 664, and a load absorbing section 80. As shown in FIG. The load detection unit 66 constitutes a blockage detection device.

As shown in FIGS. 3, 6 and 7, the load holding portion 663 is arranged to face the load receiving portion 662 arranged on the unit main body 61 when the cover portion 62 is closed, and constitutes the artery side line 21. Hold the tube to be The load pressing portion 663 may be configured to be height-adjustable so that when the diameter of the tube is changed, the voltage value output from the load detecting portion 66 is approximately the same. , and may be configured to be replaceable with load holding portions having different heights.

The load receiving portion 662 receives a load from the pressure from the tube (measurement target portion) forming the artery side line 21 held down by the load holding portion 663 when the lid portion 62 is closed. The load receiver 662 transmits the load to the force sensor 665 arranged on the substrate 664 .

As shown in FIGS. 8 to 10, the load receiving portion 662 includes a surface sheet portion 662a, a pressing portion 662b, a load shaft 71 (load portion), a guide tube 72 (contact portion), a guide tube 72 and a ground. and a connecting member 73 (connecting portion) that connects with the metal plate 610 (earth portion). The load shaft 71, the guide tube 72, the connecting member 73, and the ground metal plate 610 are made of conductive metal members. The ground metal plate 610 is formed in a plate shape and arranged inside the unit main body 61 (see FIG. 3). As shown in FIG. 9, the ground metal plate 610 is formed in a substantially C shape with one side open in plan view. The ground metal plate 610 constitutes the ground portion of the clamp unit 60 and is grounded. For example, it is grounded to the same ground as the power supply used for clamp unit 60 .

As shown in FIG. 8, the surface sheet portion 662a is arranged on the tube side, and is brought into contact with the tube constituting the arterial line 21 when the cover portion 62 is closed.
The pressing portion 662 b , the load shaft 71 and the guide tube 72 are arranged in the communication hole 615 of the unit main body 61 . The communication hole 615 is formed so that the inner surface and the outer surface 613 of the unit main body 61 communicate with each other. The surface sheet portion 662a, the pressing portion 662b, and the load shaft 71 are arranged in this order from the inner surface side of the unit main body 61 toward the outer surface 613 side.

The load shaft 71 is guided by the guide tube 72 inside the guide tube 72 on the side of the outer surface 613 of the unit body 61 in the communication hole 615 of the unit body 61, and can advance and retreat in the axial direction by pressure from the tube. placed. As shown in FIG. 10, the load shaft 71 includes a shaft main body 711 formed in a rod shape extending in the axial direction, a top plate portion 712 forming a top plate of the shaft main body 711, and a guide groove 713 (rotation preventing portion). , has

The tip of the shaft body 711 is arranged to face the pressing surface of the force sensor 665, as shown in FIG. As the shaft body 711 advances and retreats, the force sensor 665 is pressed against the tip of the shaft body 711 .
The top plate portion 712 is connected to the rear end of the shaft body 711 and formed in a disc shape protruding in the radial direction of the shaft body 711 .
The guide groove 713 extends axially across the outer peripheral surface of the top plate portion 712 and the rear end portion of the shaft body 711 in a groove shape.

The guide tube 72 is arranged in contact with the outer peripheral surface of the shaft body 711 of the load shaft 71 so as not to hinder the movement of the load shaft 71 in the axial direction. As shown in FIG. 10 , the guide tube 72 includes a tubular main body 721 extending in the axial direction of the load shaft 71 and an annular guide ring radially extending from the outer peripheral surface of the tubular main body 721 halfway in the axial direction of the tubular main body 721 . It has a projecting cylinder-side flange portion 723 and a guide projection 724 (rotation prevention portion).

The tubular main body 721 is formed in a tubular shape surrounding the entire circumference of the outer peripheral surface of the shaft main body 711 . One end portion 722 of the tube main body 721 is inserted into a connecting hole 732 of a connecting member 73 to be described later and connected to the connecting member 73 . The outer peripheral surface of the one end portion 722 of the cylinder main body 721 is formed by connecting an arc surface 722a and a linear surface 722b (rotation restricting portion) in the circumferential direction.

The shaft body 711 is housed inside the cylinder body 721 so as to be slidable in the axial direction. The inner diameter of the cylinder main body 721 is formed slightly larger than the outer diameter of the shaft main body 711 to such an extent that it contacts the shaft main body 711 without interfering with the movement of the load shaft 71 in the axial direction. More specifically, when the shaft body 711 moves in the axial direction, the shaft body 711 contacts the inside of the cylindrical body 721 in a state in which frictional resistance is less likely to be applied to the shaft body 711 in a state of contact or non-contact. are placed. Thereby, the guide tube 72 is arranged in contact with the outer peripheral surface of the load shaft 71 so as not to hinder the movement of the load shaft 71 in the axial direction.

The guide protrusion 724 protrudes in the axial direction from the end surface of the other end opposite to the one end 722 of the tubular body 721 . The guide protrusion 724 is arranged in the guide groove 713 of the load shaft 71 . The guide protrusion 724 is arranged in the guide groove 713 of the load shaft 71 to prevent the load shaft 71 from rotating with respect to the guide tube 72 . The guide tube 72 is fixed to the unit main body 61 so as not to move in the circumferential direction. In the present embodiment, as will be described later, the guide tube 72 has a linear surface 722b (rotation restricting portion) that fits into a linear surface 732b (rotation restricting portion) of the connecting member 73, so that the unit It is fixed to the main body 61 so that its position in the circumferential direction does not move. Therefore, the guide groove 713 of the load shaft 71 and the guide projection 724 of the guide tube 72 form a rotation preventing portion that prevents the load shaft 71 from rotating with respect to the force sensor 665 fixed to the unit main body 61 . Further, the guide protrusion 724 guides the movement of the guide groove 713 of the load shaft 71 when the load shaft 71 advances and retreats inside the guide tube 72 .

By having the guide groove 713 of the load shaft 71 and the guide projection 724 of the guide tube 72, the rotation of the load shaft 71 with respect to the guide tube 72 is prevented. can be brought into contact with For this reason, for example, even if the contact point is not the center of the load shaft 71 in the longitudinal direction and the length of the load shaft 71 may vary at each contact position in the circumferential direction, the load shaft 71 and Since the contact with the force sensor 665 is made at the same position in the circumferential direction, a stable load can be continuously applied and the performance can be maintained.

The connecting member 73 electrically connects the guide cylinder 72 and the ground metal plate 610 . The connecting member 73 is formed of a plate material extending in a crank shape in plan view, and a stepped portion 731 is formed in the middle of the extended crank shape. The connecting member 73 has a connecting hole 732 formed at one end and a ground connection hole 733 formed at the other end.

The connecting hole 732 is formed through the connecting member 73 at one end of the connecting member 73 . The inner peripheral surface of the connecting hole 732 is formed by connecting an arc surface 732a and a linear surface 732b (rotation restricting portion). One end portion 722 of the cylinder body 721 on the side of the outer surface 613 of the unit body 61 of the cylinder body 721 is inserted into the connection hole 732, so that the arc surface 722a and the linear surface 722b of the one end portion 722 of the cylinder body 721 are aligned with the corresponding connection hole 732. fit into the arc surface 732a and the straight surface 732b of the . The linear surface 722b (rotation restricting portion) of the guide tube 72 is fitted into the linear surface 732b (rotation restricting portion) of the connecting member 73, thereby restricting the rotation of the guide tube 72 with respect to the connecting member 73. are fixed to the unit main body 61 so as not to move in the circumferential direction. In this state, the cylinder-side flange portion 723 is in contact with the upper surface of the connecting member 73 , so that the cylinder-side flange portion 723 is electrically connected to the connecting member 73 , and the cylinder main body 721 is connected to the connecting member 73 . be done.

A ground metal plate 610 is connected to the other end of the connecting member 73 . In this embodiment, the ground connection hole 733 and the connection hole 610a of the ground metal plate 610 are connected with the screw 74 in a state where the ground metal plate 610 is placed on the upper surface of the other end of the connecting member 73. , the other end of the connecting member 73 is electrically connected to the ground metal plate 610 . As a result, the static electricity generated in the load shaft 71 is released from the guide cylinder 72 to the ground metal plate 610 via the connecting member 73 . The static electricity released to the earth metal plate 610 is earthed (grounded) at the earth metal plate 610 .

The force sensor 665 is mounted (arranged) on a first surface 664a formed on the unit main body 61 side of the substrate 664, as shown in FIG. The force sensor 665 is arranged facing the tip of the load shaft 71 and detects the load due to the pressure from the tube due to the load from the load shaft 71 . The substrate 664 is attached to the outer surface 613 of the unit body 61 . The substrate 664 is arranged to intersect the direction in which the communication hole 615 extends so as to close the communication hole 615 . The substrate 664 has a first surface 664a on the side of the unit main body 61 that abuts against the outer surface 613 of the unit main body 61, and a second surface 664b that is opposite to the first surface 664a. It is pressed toward the unit main body 61 side.

The force sensor 665 is arranged on the extension line of the communication hole 615 on the outer surface 613 side of the unit main body 61 . The load receiving portion 662 is arranged in the communication hole 615 as described above.

When the unit main body 61 is closed by the lid portion 62, the artery side line 21 is provided between the load pressing portion 663 of the lid portion 62 and the force sensor 665 from the load pressing portion 663 side toward the force sensor 665 side. The constituent tubes and load receivers 662 are arranged in this order.

The force sensor 665 configured as described above moves the load receiving portion 662 in the radial direction of the tube due to the pressure from the tube acting on the load receiving portion 662 . Detects the load due to the pressure of As a result, the force sensor 665 outputs the pressure load of the tube forming the arterial line 21 as a voltage.

In this embodiment, the force sensor 665 detects the load due to the pressure from the tube due to the load from the load shaft 71 both when the tube has a positive pressure and when the tube has a negative pressure. do.

The load absorber 80 is located on the substrate 664 as shown in FIG. The load absorbing portion 80 is configured to apply a load greater than or equal to the allowable load (a predetermined value or more) to the force sensor 665 in a state where the unit body 61 is closed by the lid portion 62 and the tube is placed between the lid portion 62 and the force sensor 665 . When applied, the load applied to the substrate 664 via the force sensor 665 is absorbed. The load absorbing portion 80 has two guide posts 81 , 81 (guide members), two spring members 82 , 82 (biasing members), and a connection member 83 connecting the spring members 82 , 82 .

In a normal use state of the clamp unit 60, when the lid portion 62 is closed, the lid portion 62 presses the tube forming the artery side line 21 toward the force sensor 665 side, so that the force sensor 665 receives the load due to the pressure from the tube. is detected and the load is output as a voltage value. A detection value detected by the load detection unit 66 is transmitted to the control device 50 to determine whether or not the tube is blocked. Obstruction of the tube includes, for example, forgetting to remove the forceps after connecting the blood circuit, clogging of the needle tip due to thrombus during blood return during treatment, and blood vessel wall at the needle tip during blood removal/dialysis. Sticking to the bloodstream, insufficient blood flow due to vascular conditions during blood removal/dialysis/blood return, and the like can be mentioned.

As shown in FIGS. 3 and 6, the arterial air bubble sensor holding member 674 is arranged to face the arterial air bubble sensor receiving member 672 arranged in the unit main body 61 when the cover 62 is closed. The tube forming the line 21 is pressed. An ultrasonic receiver 673 is arranged inside the artery-side air bubble sensor pressing member 674 . An ultrasonic oscillator 671 is arranged inside the arterial air bubble sensor receiving member 672 . The ultrasonic wave receiving section 673 and the ultrasonic wave oscillating section 671 constitute the arterial air bubble sensor 67 . The arterial bubble sensor 67 is a sensor that detects the presence or absence of bubbles contained in the liquid flowing through the arterial line 21 . Alternatively, the ultrasonic wave receiver 673 may be arranged inside the arterial air bubble sensor receiving member 672 and the ultrasonic wave oscillator 671 may be arranged inside the arterial air bubble sensor holding member 674 .

When the lid portion 62 is closed, the arterial air bubble sensor pressing member 674 (see FIG. 3) presses the tube forming the arterial line 21 against the arterial air bubble sensor receiving member 672 side. The ultrasonic wave receiving unit 673 detects the difference in transmittance between the liquid and the air bubbles by irradiating the liquid flowing in the tube forming the arterial line 21 with the ultrasonic wave generated from the ultrasonic wave oscillating unit 671 . Detects the presence or absence of air bubbles.

The pressing projection 602b of the artery-side downstream tube pressing portion 602 is arranged to face the housing recess 602a arranged in the unit main body 61 when the lid portion 62 is closed, and passes through the artery-side line 21 of the clamp unit 60. On the downstream side of the liquid (upper side in FIG. 3), the tube forming the arterial line 21 is pressed.

Next, the configuration provided in the main body side vein tube placement section 612 and the cover side vein side tube placement section 622 when the lid section 62 is closed will be described.
As shown in FIG. 3 , when the lid portion 62 is closed, along the body side vein side tube placement portion 612 and the lid side vein side tube placement portion 622 , the vein side upstream tube holding portion 603 and the vein side bubble sensor 68 are moved. , a vein side clamp portion 69 and a vein side downstream tube holding portion 604 are arranged. In the present embodiment, the vein-side upstream tube holding portion 603, the vein-side air bubble sensor 68, the vein-side clamping portion 69, and the vein-side downstream tube holding portion 604 are arranged in the clamp unit 60 from the upstream side to the downstream side (FIGS. 1 and 4). 3) are arranged side by side in this order.

The body-side vein-side tube placement portion 612 is placed on the inner surface of the unit body 61, as shown in FIG. In the body-side vein-side tube placement portion 612, vein-side upstream tube holding portions are arranged in order from the upstream side to the downstream side (from the upper side to the lower side in FIG. 3) of the liquid flowing through the tube constituting the vein-side line 22. 603, a venous air bubble sensor receiving member 682 in which the ultrasonic oscillator 681 of the venous air bubble sensor 68 is accommodated, a venous movable clamp 691 of the venous clamp 69, and a venous downstream tube holding part. The receiving recesses 604a of 604 are arranged side by side.

The lid-side vein-side tube placement portion 622 is arranged on the inner surface of the lid portion 62 and is arranged to face the body-side vein-side tube placement portion 612 when the lid portion 62 is closed. In the lid-side vein-side tube arrangement portion 622, the vein-side upstream tube retainer is arranged in order from the upstream side to the downstream side (from the upper side to the lower side in FIG. 3) of the liquid flowing through the tube constituting the intravenous line 22. a holding convex portion 603b of the portion 603, a venous air bubble sensor holding member 684 in which an ultrasonic wave receiving portion 683 of the venous air bubble sensor 68 is accommodated, a venous side clamp receiving portion 692 of the venous side clamp portion 69, and a venous downstream tube. The pressing projections 604b of the pressing portion 604 are arranged side by side.

The pressing projection 603b of the vein-side upstream tube pressing portion 603 is arranged to face the accommodation recess 603a arranged in the unit main body 61 when the lid portion 62 is closed, and prevents the liquid flowing through the vein-side line 22 in the clamp unit 60. The tube forming the venous line 22 is pressed on the upstream side of (upper side in FIG. 3).

The venous air bubble sensor pressing member 684 is arranged to face the venous air bubble sensor receiving member 682 arranged in the unit main body 61 and presses the tube constituting the venous line 22 when the lid portion 62 is closed. An ultrasonic receiver 683 is arranged inside the venous air bubble sensor pressing member 684 . An ultrasonic oscillator 681 is arranged inside the venous air bubble sensor receiving member 682 . The ultrasonic wave receiving section 683 and the ultrasonic wave oscillating section 681 constitute the venous air bubble sensor 68 . The venous air bubble sensor 68 is a sensor that detects the presence or absence of air bubbles contained in the liquid flowing through the venous line 22 . The ultrasonic wave receiving section 683 may be arranged inside the venous air bubble sensor receiving member 682 and the ultrasonic wave oscillator 681 may be arranged inside the venous air bubble sensor receiving member 684 .

When the lid 62 is closed, the venous air bubble sensor pressing member 684 (see FIG. 3) presses the tube forming the venous line 22 against the venous air bubble sensor receiving member 682 side. The ultrasonic wave receiving unit 683 detects the difference in transmittance between the liquid and the air bubbles by irradiating the liquid flowing in the tube forming the vein side line 22 with the ultrasonic wave generated from the ultrasonic wave oscillating unit 681 . Detects the presence or absence of air bubbles.

The vein side clamp receiving portion 692 is arranged to face the vein side movable clamp portion 691 arranged on the unit main body 61 when the lid portion 62 is closed. The vein side clamp receiving portion 692 and the vein side movable clamp portion 691 constitute the vein side clamp portion 69 and sandwich and hold the tube constituting the vein side line 22 .

As shown in FIGS. 3 and 7, the vein side clamp section 69 includes a vein side movable clamp section 691 arranged in the unit main body 61 and a solenoid 693 arranged in the unit main body 61 for driving the vein side movable clamp section 691. , and a venous clamp receiving portion 692 arranged on the lid portion 62 . The vein-side clamp receiving portion 692 is formed to protrude from the inner surface of the lid portion 62 and extends in the width direction H. As shown in FIG.

The vein-side movable clamp part 691 has a flat tip extending in the width direction H and a trapezoidal shape with a narrow width on the tip side in a cross section cut in the direction in which the tube placement part extends. An output shaft 693a of a solenoid 693 is connected to the rear end of the vein side movable clamp section 691 so as to be able to advance and retreat. The movable vein clamp section 691 pinches and clamps the tube forming the vein line 22 between the tip of the movable vein clamp section 691 and the tip of the clamp receiving section 692 by advancing and retracting the output shaft 693 a of the solenoid 693 . Alternatively, the venous line 22 is opened and closed.

The vein clamp section 69 configured as described above is arranged between the unit main body 61 and the lid section 62 by the vein movable clamp section 691 and the vein clamp receiving section 692 during normal operation of the hemodialysis apparatus 1. Clamp the tube that constitutes the venous line 22 to be inserted.
In addition, the vein side clamp section 69 is controlled according to the detection result of bubbles by the vein side bubble sensor 68 or the artery side bubble sensor 67 . When the venous air bubble sensor 68 or the arterial air bubble sensor 67 detects more than a predetermined amount of air bubbles, the venous clamp section 69 advances the venous movable clamp section 691 to form the venous line 22 . By crushing the tube and closing the flow path of the intravenous line 22 , the liquid feeding inside the tube is stopped on the upstream side of the intravenous bubble sensor 68 .

When the lid portion 62 is closed, the holding projection 604b of the vein-side downstream tube holding portion 604 is arranged to face the housing recess 604a arranged in the unit main body 61, and passes through the vein-side line 22 of the clamp unit 60. On the downstream side of the liquid (lower side in FIG. 3), the tube forming the venous line 22 is pressed.

With the clamp unit 60 constructed as described above, the clamp unit 60 can be clamped by simply closing the cover 62 in a state in which the tubes constituting the arterial line 21 and the venous line 22 are arranged in the unit main body 61 . At 60 the tube can be securely clamped.

The control device 50 is configured by an information processing device (computer), and controls the operation of the dialysis machine 1 by executing a control program. The controller 50 controls and operates the hemodialysis apparatus 1 by executing control programs for various processes. Specifically, the control device 50 controls various pumps and clamps arranged in the blood circuit 20 and the dialysate circuit 30, and the operation of the heater 40, etc., to perform various processes (priming, process, blood removal process, dialysis process, fluid replacement process, blood return process, etc.). In the various steps of the hemodialysis apparatus 1 of the present embodiment, for example, the priming step, the blood removal step, the dialysis step, and the blood return step are executed in this order, and the execution time of all these steps takes about 4 to 5 hours. .

The priming step is a preparatory step for washing and cleaning the blood circuit 20 and the dialyzer 10 .
The blood removal step is a step of filling the blood circuit 20 with the patient's blood after the puncture and circulating it extracorporeally.
The dialysis step is performed following the blood removal step, and is a step of dialyzing and purifying the blood.
The fluid replacement step is a step of performing rapid fluid replacement when blood pressure drops or the like during dialysis treatment.
The blood return process is a process of returning the blood in the blood circuit 20 to the patient's body.

Here, in the present embodiment, the control device 50 performs an operation of determining blockage of the tube, an operation of correcting the reference voltage (reference value) according to the elapsed time of use of the tube, and the operation of adjusting the hardness of the tube to the clamp unit. and an operation to give an alarm when the hardness of the tube used for 60 is not met.

In order to implement the above functions, the control device 50 includes a control section 51 and a storage section 52, as shown in FIG. The control unit 51 includes a blockage determination unit 511 , a correction control unit 512 and a notification control unit 513 .

The storage unit 52 stores in advance a reference voltage (reference value) that serves as a reference for judging clogging of the tube according to the elapsed time for the liquid to flow through the tube. The reference voltage serves as a reference for judging blockage of the tube, and is the output voltage of the load detecting section 66 when no pressure is applied to the inside of the tube (when the blood pump 212 is stopped). , is the output voltage when the tube is not occluded. For example, a value obtained by subtracting a certain voltage from the reference voltage is set as a threshold value of the output voltage of the load detection unit 66 when the tube becomes negative pressure, and a value added by a certain voltage is set as a positive pressure in the tube. It can be set to the threshold value of the output voltage of the load detection unit 66 in the case. Alternatively, in consideration of negative pressure and positive pressure, a value within a range obtained by adjusting the absolute value of a constant voltage may be used as a threshold value in various steps (for example, the negative pressure determination threshold value Va shown in FIG. 12, the positive pressure determination threshold value Vb). As a result, even if the tube becomes accustomed to the liquid or changes in temperature over time, the reference voltage stored in the storage unit 52 can be updated by the correction control unit 512, which will be described later. The reference voltage stored in the storage unit 52 is obtained in advance based on experimental results or the like.
Note that the storage unit 52 may store in advance a reference voltage (reference value) that serves as a reference for judging clogging of the tube according to differences in the outer size of the tube, temperature changes, and the like.

The occlusion determination unit 511 compares the detection value detected by the load detection unit 66 with a occlusion threshold value set based on a reference voltage that serves as a reference for determining occlusion of the tube, thereby determining occlusion of the tube. do.

The correction control unit 512 updates and corrects the reference voltage according to the elapsed time, based on the reference voltage stored in the storage unit 52 and serving as a reference for determining whether the tube is clogged. The timing of the correction by the correction control unit 512 is, for example, real-time timing, timing at predetermined time intervals, predetermined timing of dialysis treatment, or the like.

When the clogging determination unit 511 determines that the tube is clogged, the notification control unit 513 issues an alarm using a notification unit such as a display screen, an indicator lamp, or a speaker.

In addition, when it is determined that the detection value detected by the load detection unit 66 when the lid unit 62 is closed is out of the preset range, the notification control unit 513 notifies, for example, a display screen, an indicator lamp, a speaker, or the like. Department will issue an alarm. As a result, an alarm is issued when the hardness, diameter, or wall thickness of the tube is not appropriate, or when the tube is deformed. values can be obtained with high accuracy.

Here, in the load receiving portion 662 of the present embodiment, the guide tube 72 is arranged in contact with the outer peripheral surface of the load shaft 71 so as not to hinder the movement of the load shaft 71 in the axial direction. The reason why it is configured to be grounded via the connecting member 73 will be described.

Conventionally, in the clamp unit 60, the load shaft 71 is charged with static electricity due to the forward/backward movement of the load shaft 71. Due to the influence of the static electricity, the output voltage of the load detection unit 66 becomes an abnormal value, and the force sensor 665 makes an erroneous detection. something happened.

For example, even though the output voltage Vs of the load detection unit 66 is within the range of the negative pressure determination threshold value Va, as shown in FIG. An output below the range of Va was generated, and output abnormalities due to the effects of static electricity sometimes occurred. In this case, the force sensor 665 makes an erroneous detection.
In addition, although the output voltage Vs of the load detector 66 is within the range of the positive pressure determination threshold value Vb, as shown in FIG. An output exceeding the range of Vb was generated, and an abnormal output was caused due to the influence of static electricity. In this case, the force sensor 665 makes an erroneous detection.

On the other hand, in the present invention, in the load receiving portion 662, the guide tube 72 is arranged in contact with the outer peripheral surface of the load shaft 71 so as not to hinder the movement of the load shaft 71 in the axial direction, and the guide tube 72 is connected to the ground via the connecting member 73, thereby allowing the static electricity generated in the load shaft 71 to escape to the ground. As a result, erroneous detection of the force sensor 665 due to static electricity is prevented without impeding the movement of the load shaft 71 in the axial direction, and the force sensor 665 accurately detects both the negative pressure and the positive pressure of the tube. can do.

In particular, in the case of single-needle dialysis in which a single needle is inserted into a patient and both blood withdrawal and blood return are performed continuously, the clamping operation and the clamp releasing operation are performed every few seconds. In the case of single-needle dialysis, static electricity is likely to occur because the clamping operation is performed every few seconds. However, even when there is an effect of static electricity generated by frequent clamping operations, according to the present invention, erroneous detection due to the effect of static electricity can be preferably prevented.

Furthermore, the load detection section 66 in the present invention has a precise structure so that the force sensor 665 can accurately detect both the negative pressure and the positive pressure of the tube. Specifically, the guide tube 72 is arranged in contact with the outer peripheral surface of the load shaft 71 so as not to hinder the movement of the load shaft 71 in the axial direction. The load shaft 71 accommodated in the guide tube 72 can move forward and backward along the guide tube 72 in the axial direction. A force sensor 665 facing the tip of the load shaft 71 detects both the load due to the pressure in the tube when the tube is under negative pressure and the pressure when the tube is under positive pressure.

Here, for example, if a wiring is attached to the load shaft 71 and static electricity is released to the ground, resistance is applied to the load shaft 71 due to the influence of the wiring attached to the load shaft 71, and the force sensor 665 is connected to the tube. Both negative and positive pressure may not be detected accurately. On the other hand, according to the configuration of the present invention, the force sensor 665 can detect both the negative pressure and the positive pressure of the tube with higher accuracy than the configuration in which a wiring is attached to the load shaft 71 to discharge static electricity to the ground.

Further, for example, if a copper foil is sandwiched between the load shaft 71 and the force sensor 665 and static electricity is released to the ground via the copper foil, the copper foils are overlapped in the moving direction of the load shaft 71. Therefore, there is a possibility that the force sensor 665 cannot accurately detect both the negative pressure and the positive pressure of the tube. In addition, it is also conceivable that the thickness of the copper foil changes due to deterioration over time, making it impossible to accurately detect both the negative pressure and the positive pressure of the tube. On the other hand, according to the configuration of the present invention, the force sensor 665 can accurately detect both negative pressure and positive pressure, and since deterioration over time is less than that of copper foil, durability can be improved, and long-term Maintains performance even when used.

Further, for example, in the case of a configuration in which a metal brush is brought into contact with the outer peripheral surface of the load shaft 71 to prevent static electricity charging, the brush portion of the metal brush comes into contact with the outer peripheral surface of the load shaft 71 and the load shaft 71 is affected. 71 may be subjected to resistance, and the metal brushes may deteriorate over time. In contrast, according to the configuration of the present invention, the force sensor 665 detects both the negative pressure and the positive pressure more accurately than the configuration in which the metal brush is brought into contact with the outer peripheral surface of the load shaft 71 to prevent electrostatic charging. Since it can be detected stably and deteriorates less over time than a metal brush, the durability can be improved. The unit 60 can be formed compactly.

According to the load detection section 66 of this embodiment described above, the following effects can be obtained.

(1) The load detection section 66 includes the unit body 61 and the lid section 62 that opens and closes the unit body 61, and is arranged between the unit body 61 and the lid section 62 when the lid section 62 is closed. A load detection unit 66 that detects the load due to the pressure from the tube that is applied, the load shaft 71 that can move forward and backward in the axial direction by the pressure from the tube, and the load shaft 71 that is disposed facing the tip of the load shaft A force sensor 665 for detecting a load, a guide cylinder 72 arranged in contact with the outer peripheral surface of the load shaft 71 so as not to hinder the movement of the load shaft 71 in the axial direction, and an electrical connection between the guide cylinder 72 and the earth plate 610. and a load detecting portion 66 having a coupling member 73 that is physically connected. As a result, the force sensor 665 can accurately detect both the negative pressure and the positive pressure of the tube without hindering the movement of the load shaft 71 in the axial direction. can be prevented. In addition, the detection performance of the force sensor 665 can be maintained even after long-term use because deterioration over time is less than in the case of using a copper foil or a metal brush, for example.

(2) The guide tube 72 is formed in a tubular shape. Therefore, since the guide tube 72 is arranged so as to surround the entire circumference of the load shaft 71 , the load shaft 71 can easily come into contact with any portion of the inner peripheral surface of the guide tube 72 . Thereby, the load shaft 71 can be brought into contact with the guide tube 72 stably. Therefore, it is possible to further prevent the force sensor 665 from making an erroneous detection due to the influence of static electricity.

(3) It further includes a guide groove 713 and a guide protrusion 724 that prevent rotation of the load shaft 71 . Since this prevents the load shaft 71 from rotating, the load shaft 71 and the force sensor 665 can always be brought into contact at the same position in the circumferential direction. Therefore, for example, even if the contact point is not the center of the load shaft 71 in the longitudinal direction and the length of the load shaft 71 may vary at each contact position in the circumferential direction, the load shaft 71 and the force Since the sensor 665 is in contact with the sensor 665 at the same position in the circumferential direction, a stable load can be continuously applied and the performance can be maintained.

(4) The clamp unit 60 is configured to include the load detection section 66 so that the tube placed between the unit main body 61 and the lid section 62 can be clamped when the lid section 62 is closed. As a result, for example, in the case of single-needle dialysis, erroneous detection of the force sensor 665 due to the effects of static electricity can be preferably prevented even when there is the effect of static electricity generated by frequent clamping operations.

Although preferred embodiments of the load detector 66 and the clamp unit 60 of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate.
For example, in the above embodiment, the load shaft 71 is formed in a cylindrical shape, but it is not limited to this. For example, the shaft main body 711A of the load shaft 71A may be formed of a square pole as in the first modified embodiment shown in FIG. It may be formed with a triangular prism.

Further, in the above-described embodiment, the contact portion is formed by the tubular guide tube 72, but the present invention is not limited to this. For example, the contact portion may be formed in a C shape that does not surround the entire circumference of the load shaft 71 like the contact portion main body 721A of the contact portion 72A of the third modification shown in FIG. It may be formed in a bar shape like the contact portion 72B of the four modified forms. When the contact portion is formed of a rod-shaped contact portion 72B, as shown in FIG. It is preferably formed into a shape.

In addition, although the connecting member 73 is formed of a plate material extending in a crank shape in plan view, the shape is not limited as long as it can be grounded (grounded). .

Further, in the above-described embodiment, the case where the load detection section (load detector) is applied to the clamp unit has been described, but the present invention is not limited to this and may be used for other applications. For example, the load detector (load detector) is preferably used in an environment where static electricity is generated.

60 clamp unit 61 unit main body (main body)
62 lid portion 66 load detection portion (load detector)
71 load shaft (load part)
72 guide tube (contact part)
73 connecting member (connecting part)
610 Ground sheet metal (ground part)
665 force sensor (load detection sensor)
713 guide groove (rotation prevention part)
724 guide projection (rotation prevention part)

Claims (4)

A load detector comprising a main body and a lid portion for opening and closing the main body, and detecting a load due to pressure from a measurement target portion disposed between the main body and the lid portion when the lid portion is closed. There is
a load portion that can advance and retreat in the axial direction by pressure from the measurement target portion;
a load detection sensor arranged to face the tip of the load portion and detecting the load from the load portion;
a contact portion arranged in contact with the outer peripheral surface of the load portion so as not to hinder the movement of the load portion in the axial direction;
A load detector comprising: a connecting portion that electrically connects the contact portion and the ground portion. The load detector according to claim 1, wherein the contact portion is cylindrical. 3. The load detector according to claim 1, further comprising a rotation preventing portion that prevents rotation of the load portion. A load detector according to any one of claims 1 to 3,
The measurement target part is a tube through which liquid flows,
A clamping unit further comprising a clamping part arranged between the main body and the lid, capable of clamping the tube when the lid is closed.

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