JP2018066607A - Load detector and load detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load detector which allows a subject to be easily mounted on a mount part.SOLUTION: A load detector includes: a load detection part having a movement base part, a first beam shape load cell supported on the movement base part in a cantilevered manner to have a free end, and a mount part which is connected to the free end of the first beam shape load cell and on which the subject is mounted; and a fixation base part supporting the load detection part while allowing the load detection part to rotate around a predetermined rotation center.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a load detector including a load detector that can rotate around a predetermined center of rotation, and a load detection system including the load detector.

  In-bed detection is known in which a load applied to a bed in a hospital or a nursing facility is detected to determine whether a patient or a resident is present on the bed. The load detector for detecting the load can be arranged at various positions, for example, under the supporting leg of the bed.

  In Patent Document 1, as a load detector that can be placed under a leg of a bed, a cantilever portion to which a strain gauge is attached and a mounting plate portion attached to a base end portion of the cantilever portion. A load detector is disclosed.

Japanese Patent No. 4829020

  Some heavy objects such as beds are provided with casters so that they can be moved without lifting the heavy objects, but it is difficult to say that moving heavy objects using casters is easy. In particular, by operating four casters provided under the four legs of the bed, the four casters are simultaneously placed on the placement plate portion of the load detector as disclosed in Patent Document 1. Is a time-consuming task.

  Then, an object of this invention is to provide the load detector which can mount a test subject on a mounting part easily.

According to the first aspect of the present invention,
A moving base, a first beam-type load cell having a free end by being cantilevered on the moving base, and a mounting on which the subject is mounted and connected to the free end of the first beam-type load cell A load detector having a portion;
A load detector is provided that includes a fixed base that supports the load detector so as to be rotatable about a predetermined center of rotation.

  In the load detector according to the first aspect, the subject may be a rolling element that rolls from the front to the rear along the first direction and is placed on the placement unit, and the predetermined rotation center. May be located outside the fixed base and in front of the mounting portion in the first direction.

  In the load detector according to the first aspect, the load detection unit may further include a second beam-type load cell having a free end by being cantilevered on the moving base. Further includes a first connecting part connected to the first beam-type load cell and a second connecting part connected to the second beam-type load cell, the first beam-type load cell and the second beam-type load cell. The first connecting portion of the mounting portion may be connected to the first beam-type load cell on the free end side of the first beam-type load cell. The second connecting portion may be connected to the second beam-type load cell on the free end side of the second beam-type load cell.

  In the load detector according to the first aspect, the free end of the first beam-type load cell and the free end of the second beam-type load cell may face opposite sides.

  In the load detector according to the first aspect, the placement unit is a regulation unit that regulates movement of the subject, and the subject whose movement is regulated by the regulation unit is the first beam-type load cell. You may have a control part provided so that it may be located on the line segment which connects the free end vicinity and the said free end vicinity of a 2nd beam-type load cell.

  The load detector according to the first aspect is further fixed to the slope that guides the subject onto the placement part or the placement part, and is fixed to the moving base, and the subject is placed on the placement part. You may have a slope to guide.

According to the second aspect of the present invention,
A load detection system for detecting the load of a subject on a bed,
A plurality of load detectors of the first aspect located under a bed leg caster;
There is provided a load detection system having a control unit connected to the plurality of load detectors and calculating a load of the subject based on an output of the load detectors.

  According to the load detector of the present invention, the subject can be easily placed on the placement portion.

FIG. 1 is an exploded perspective view of a load detector according to the first embodiment of the present invention. FIG. 2 is a perspective view of the load detector according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram illustrating a state in which the caster is placed on the placement unit of the load detection unit. FIG. 4 is an explanatory diagram for explaining the relationship between the mounting position of the mounting portion on the first and second beam type load cells and the preferable mounting position of the subject on the mounting portion. FIG. 5 is a schematic plan view of a load detector having one beam-type load cell. FIG. 6 is a schematic plan view of the load detector according to the first embodiment of the present invention. Fig.7 (a)-FIG.7 (c) are top views of the load detector of a modification. FIG. 8 is a schematic diagram showing the configuration of a load detection system according to the second embodiment of the present invention.

<First Embodiment>
With reference to FIGS. 1-5, the load detector 100 of 1st Embodiment of this invention is demonstrated. In the following description, a caster CT (FIG. 3) attached to the lower ends of four legs of a bed (not shown) in order to detect the load of the subject on the bed is placed on a placement unit 3 (described later). A case where the detection is performed will be described as an example.

  As shown in FIGS. 1 and 2, the load detector 100 according to the first embodiment includes a moving base 1, first and second beam-type load cells 21 and 22 that are cantilevered in parallel by the moving base 1, 1 and a load detecting unit 100A having a mounting unit 3 supported by the second beam type load cells 21 and 22 so as to be finely movable up and down. The load detector 100 further includes a fixed base 4 that supports the load detector 100A so as to be rotatable about a center point O (center of rotation, FIG. 3).

  In the following description, the direction in which the first and second beam-type load cells 21 and 22 extend is the front-rear direction of the load detection unit 100A, and the side on which the slope 13 (described later) is disposed with respect to the placement unit 3. Is the front side and the opposite side is the rear side. The circumferential direction around the center point O is referred to as the rotation direction of the load detector 100.

  The movable base 1 is a flat bottom 10 and box-shaped first and second support bases 11 and 12 that are provided on the upper surface of the bottom 10 and cantilever-support the first and second beam load cells 21 and 22, respectively. And a slope 13 provided at the front edge of the bottom 10 and a pair of guide rails 141 and 142 provided on the lower surface of the bottom 10. The moving base 1 is made of, for example, metal.

  The bottom portion 10 is a rectangular flat plate whose longitudinal direction coincides with the front-rear direction and whose transverse direction substantially coincides with the rotational direction, and the first and second support base portions 11 and 12 are provided at diagonal portions thereof. . The first support base part 11 and the second support base part 12 are arranged such that they are separated from each other by a predetermined distance in the lateral direction, and the second support base part 12 is in front of the first support base part 11. . The separation distance in the short direction of the first and second support bases 11 and 12 is substantially equal to the width of the mounting portion 3 described later.

  The slope 13 is an inclined surface that assists the movement (rolling) of the subject such as a caster onto the placement unit 3. The slope 13 is provided at the center of the front edge of the bottom 10 so as to be positioned between the first support base 11 and the second support base 12 in the short direction.

  The lower side of the slope 13 extends to the lower surface of the bottom portion 10, and the lower edge 131 of the slope 13 is connected to the lower surface of the bottom portion 10. The lower edge 131 of the slope 13 has an arc shape along the circumference around the center point O in plan view. The upper edge 132 of the slope 13 is located slightly higher than the upper surfaces of the first and second support bases 11 and 12.

  A pair of guide grooves 141 and 142 extending in the rotation direction (that is, along the circumference around the center point O) are provided on the lower surface of the bottom portion 10.

  The first and second beam type load cells 21 and 22 have strain-generating bodies 21s and 22s having the same shape, and strain gauges 21g and 22g attached to the strain-generating bodies 21s and 22s, respectively.

  Each of the strain generating bodies 21s and 22s is a Roberval type strain generating body formed of a metal such as aluminum or iron, and has a prismatic shape having a through hole (not shown) penetrating in the width direction. One strain gauge 21g is attached to each of the upper and lower surfaces near the through hole of the strain generating body 21s. Similarly, one strain gauge 22g is attached to each of the upper and lower surfaces of the strain generating body 22s near the through hole. It is pasted one by one.

  The bottom surface of the strain generating body 21s is fixed to the first support base 11 of the moving base 1 so that the moving base 1 is cantilevered with the rear end serving as the fixed end 21s1 and the front end serving as the free end 21s2. Has been. On the other hand, the lower surface in the vicinity of the front end of the strain generating body 22s is fixed to the second support base part 12 disposed in front of the first support base part 11, whereby the front end is fixed to the fixed end 22s1 and the rear end. Is cantilevered by the movable base 1 as a free end 22s2. That is, the free end 21s2 of the strain generating body 21s and the free end 22s2 of the strain generating body 22s are opposite to each other in the front-rear direction.

  In addition, the fixed end 21s1 and the free end 21s2 of the strain body 21s are substantially at the same positions as the free end 22s2 and the fixed end 22s1 of the strain body 22s in the front-rear direction. Therefore, the support base 11 of the moving base 1 is substantially in the same position as the free end 22s2 of the strain body 22s in the front-rear direction, and the support base 12 is in the same position as the free end 21s2 of the strain body 21s.

  The placement unit 3 is a weighing pan on which casters (subjects) attached to the legs of the bed are placed. A rectangular placement plate 31 on which the subject is placed on an upper surface thereof, and a placement plate 31. And a substantially U-shaped (substantially U-shaped) wall portion 32 standing upright.

  The mounting plate 31 is a rectangular flat plate whose longitudinal direction coincides with the front-rear direction and whose transverse direction substantially coincides with the rotational direction. The wall portion 32 includes first and second long walls 321 and 322 extending in the front-rear direction in parallel with each other, and a short wall 323 extending between the rear end of the first long wall 321 and the rear end of the second long wall 322. .

  Each of the first and second long walls 321 and 322 extends forward from a substantially central portion in the long side direction of the mounting plate 31 along each long side and protrudes forward from the front end of the mounting plate 31. The short wall 323 extends along the short side direction of the mounting plate 31 throughout the short side direction. When a subject such as a caster is placed in a region surrounded by the first and second long walls 321 and 322 and the short wall 323 on the upper surface of the mounting plate 31, the first and second long walls 321 and 322 are arranged. This prevents contact between the subject and the first and second beam-type load cells 21 and 22, and the short wall 323 prevents excessive entry of the subject rearward.

  A flat plate-like first connecting portion 331 protrudes from the outer surface of the first long wall 321 protruding forward from the mounting plate 31 (the surface facing the opposite side of the mounting plate 31). A flat plate-like second connection portion 332 protrudes from the vicinity of the rear end of the long side on the second long wall 322 side. The first connecting portion 331 is connected to the lower surface near the free end 21s2 of the strain body 21s, and the second connecting portion 332 is connected to the lower surface near the free end 22s2 of the strain body 22s.

  Thus, the mounting portion 3 is disposed so as to face the opposite side in the front-rear direction via the first and second connecting portions 331 and 332 provided at substantially diagonal positions of the rectangular mounting plate 31. Are connected to the free ends 21 s 2 and 22 s 2 of the strain generating bodies 21 s and 22 s, so that they are supported by the strain generating bodies 21 s and 22 s and eventually the first and second beam-type load cells 21 and 22 so as to be movable in the vertical direction. ing. In addition, in the state where the mounting portion 3 is supported by the first and second beam-type load cells 21 and 22, the front edge of the mounting plate 31 has a gap with the upper edge 132 of the slope 13 of the moving base portion 10. Opposite.

  The fixed base 4 includes a bottom 40 that is a fan-shaped flat plate, a pair of guide rails 411 and 412 provided on the upper surface of the bottom 40, and a slope 42 provided on the inner periphery of the bottom 40. The fixed base 4 is made of, for example, metal or resin.

  A pair of guide rails 411 and 412 provided on the inner and outer peripheral edges of the sector-shaped bottom portion 40 and the upper surface of the bottom portion 40 respectively extend in the rotation direction.

  A slope 42 extending in the rotation direction along the inner peripheral edge is provided on the inner peripheral edge of the bottom portion 40. The lower edge 421 and the upper edge 422 of the slope 42 are both arcs extending in the rotation direction in plan view. The slope 42 assists the movement (rolling) of the subject such as a caster onto the placement unit 3.

  The moving base 1 of the load detecting unit 100A is placed on the upper surface of the bottom 40 of the fixed base 4 with the guide rails 411 and 412 of the fixed base 4 fitted in the guide grooves 141 and 142 of the moving base 1, respectively. Yes. Thereby, the fixed base 4 supports the movable base 1 so as to be rotatable in the rotation direction.

  In a state where the moving base 1 is supported by the fixed base 4, the lower edge 131 of the slope 13 of the moving base 1 and the upper edge 422 of the slope 42 of the fixed base 4 are close to each other, and the combination of the slope 13 and the slope 42 One smoothly connected inclined surface is defined (FIG. 2). This inclined surface is maintained even when the load detection unit 100A rotates.

  Next, the usage method and operation | movement of the load detector 100 of this embodiment are demonstrated.

  When detecting the load of the subject on the bed using the load detector 100 of the present embodiment, first, four casters provided at the lower ends of the four legs of the bed are respectively mounted on the load detector 100. Place on the placement unit 3.

  Specifically, as shown in FIG. 3, the caster CT provided at the lower end of the leg portion of the bed is arranged in front of the load detection unit 100A of the load detector 100, and the caster CT is arranged in the front-rear direction of the load detection unit 100A. Roll from front to back along

  As a result, the caster CT rolls on the slope 42 of the fixed base 4 and the slope 13 of the moving base 1 and is placed on the placement part 3 of the load detection part 100A.

  Here, the caster CT rotates about the axis X extending in the vertical direction along the leg of the bed, and the traveling direction can be freely changed. Therefore, when the caster CT is disposed in front of the load detection unit 100A, the traveling direction of the caster CT may not coincide with the front-rear direction of the load detection unit 100A as indicated by a dotted line in FIG.

  In this case, the load detection unit 100A is rotated around the center point O and moved in the direction of arrow A in FIG. 3, and the front-rear direction of the load detection unit 100A is made to match or approximate the traveling direction of the caster CT. The caster CT is placed on the placement unit 3.

  Here, the reason why the load detector 100 of the present embodiment supports the mounting portion 3 at two points using the first beam type load cell 21 and the second beam type load cell 22 will be described.

  In the load detector 100 of the present embodiment, as shown in FIG. 4, the placement unit 3 is connected to the vicinity of the free end 21 s 2 of the strain body 21 s of the first beam type load cell 21 through the first connection unit 331. And connected to the vicinity of the free end 22 s 2 of the strain body 22 s of the second beam type load cell 22 via the second connecting portion 332.

  Here, assuming that the center point of attachment of the first connecting portion 331 to the strain generating body 21s is the attachment center C1, and the center point of attachment of the second connection portion 332 to the strain generating body 22s is the attachment center C2, the placement is performed. The mounting plate 31 of the part 3 is most difficult to bend on a line segment L connecting the attachment center C1 and the attachment center C2 with the shortest distance. Therefore, by placing the bed casters CT on the line segment L, it is possible to detect the load of the subject on the bed without being affected by the deflection of the placement portion 3. In the load detector 100 of the present embodiment, the short wall 323 is disposed so that the caster CT that is in contact with the short wall 323 and is restricted from moving forward is positioned on or near the line segment L. ing.

  Here, as in the load detector 100 of the present embodiment, the mounting portion 3 is supported at two points by the first and second beam-type load cells 21 and 22 with the free ends facing the opposite side, so-called displacement. The generation of errors can be suppressed. The reason will be explained.

  As shown in FIG. 5, in the load detector 900 in which the mounting plate PT is attached to the end portion of the beam type load cell LC, the displacement error is caused by the fact that the mounting position p of the subject is the beam type load cell LC and the mounting plate. Although it is relatively small in the vicinity of the connection position C0 with PT, the placement position p becomes larger as the distance from the connection position C0 increases. This is because, as the mounting position p is separated from the connection position C0 in the longitudinal direction of the beam-type load cell LC, a bending moment having a magnitude corresponding to the separation distance about the axis extending in the width direction of the beam-type load cell LC is obtained. This is because it acts on the strain-generating body of the beam-type load cell LC, and the strain due to this bending moment causes an offset error in the strain gauge of the beam-type load cell LC. Further, as the mounting position p moves away from the connection position C0 in the width direction of the beam type load cell LC, a torsional moment having a magnitude corresponding to the separation distance around the axis extending in the longitudinal direction of the beam type load cell LC is increased. This is because an offset error occurs in the strain gauge of the beam type load cell LC due to the strain caused by the torsional moment.

On the other hand, in the load detector 100 of the present embodiment, as shown in FIG. 6, the placement plate 31 of the placement unit 3 (in FIG. 6, all the space between the first and second beam type load cells 21, 22). X _P1 is the longitudinal distance between the mounting position P and the mounting center C1 of the subject placed on the object) (shown as spreading over the area), and the longitudinal distance between the mounting position P and the mounting center C2 When the distance is referred to as _{x P2,} the sum of _{x P1} and _{x P2} is constant at substantially the entire region on the mounting plate 31 of the platform 3. Therefore, in the load detector 100 of the present embodiment, even if the placement position P moves in the front-rear direction, the displacement error due to the bending moment generated in the first beam type load cell 21 and the bending moment generated in the second beam type load cell 22. The sum of the deviation error due to is always substantially constant. Therefore, for example, in the control unit (not shown), the detection values of the first beam type load cell 21 and the second beam type load cell 22 are added, and a value having a certain ratio to the detection value is subtracted as an offset error. By performing this process, it is possible to stably detect the load to be detected in a state in which the influence of the displacement error caused by the bending moment is substantially removed.

In addition, as shown in FIG. 6, the distance in the width direction between the mounting position P of the detection target mounted on the mounting plate 31 of the mounting unit 3 and the mounting center C1 is y _P1 , and the mounting position P and the mounting When the widthwise distance between the center C2 and _{y P2,} the sum of the _{y P1} and _{y P2} is constant at substantially the entire region on the mounting plate 31 of the platform 3. Therefore, in the load detector 100 of the present embodiment, even if the mounting position P moves in the width direction, the displacement error due to the torsional moment generated in the first beam type load cell 21 and the torsional moment generated in the second beam type load cell 22. The sum of the deviation error due to is always substantially constant. Therefore, the load to be measured can be stably detected in the state where the influence of the displacement error caused by the torsional moment is substantially removed by the same processing as in the case of the bending moment.

  The effects of the load detector 100 of this embodiment are summarized below.

  In the load detector 100 of the present embodiment, the load detection unit 100A is rotated around the center point O, and the direction in which the front and rear direction of the load detection unit 100A extends (the direction in which the caster CT enters the placement unit 3). Can be easily changed. Therefore, when a subject such as a caster CT is placed on the placement unit 3 of the load detection unit 100A, the front-rear direction of the load detection unit 100A can be easily matched or approximated to the traveling direction of the caster CT. Can be placed.

  In the load detector 100 of the present embodiment, the center point O of rotation of the load detection unit 100A is defined in front of the load detection unit 100A and will be placed on the placement unit 3 of the load detection unit 100A. Is defined in the vicinity of the axis X of the caster CT. Therefore, as shown in FIG. 3, even when the load detection unit 100A is rotated in accordance with the rotation of the caster CT (change in the traveling direction), the front surface of the caster CT in the traveling direction and the slope 13 of the load detecting unit 100A are approximately. The opposing state can be maintained. Therefore, it is easy to adjust the extending direction of the load detector 100A in the front-rear direction according to the rotation of the caster CT (change in the traveling direction).

  In the load detection unit 100A of the load detector 100 of the present embodiment, the mounting unit 3 is supported by the first and second beam-type load cells 21 and 22 that are arranged so that the free ends face opposite to each other. . Therefore, in the detection of the load of the subject using the load detection unit 100A, the influence of the offset error is suppressed.

  In the load detection unit 100A of the load detector 100 of the present embodiment, the mounting plate 31 is provided via first and second connecting portions 331 and 332 provided at diagonal positions of the mounting plate 31 of the mounting unit 3. Support. Accordingly, by placing the subject on or near the line segment L connecting the attachment centers C1 and C2 of the first and second connecting portions 331 and 332 to the strain generating bodies 21s and 22s, the placement plate The influence of the 31 deflection on the detection of the load fluctuation of the subject can be suppressed. In addition, since the short wall 323 is arranged so that the caster CT that is in contact with the short wall 323 and is prevented from moving forward is located on the line segment L or in the vicinity thereof, the subject is placed on the placement plate 31. It can be easily placed at a suitable position.

<Modification>
In the load detector 100 according to the first embodiment, the following modification may be employed.

  In the load detector 100 of the first embodiment, the guide grooves 141 and 142 are provided in the moving base 1 and the guide rails 411 and 412 are provided in the fixed base 4, but the present invention is not limited to this.

  As another example, the moving base 1 may be provided with a guide rail, and the fixed base 4 may be provided with a guide groove. Alternatively, a guide groove is provided on both the lower surface of the movable base 1 and the upper surface of the fixed base 4, and the movable base 1 is disposed on the upper surface of the fixed base 4 with a guide ball sandwiched between both guide grooves. The movable base 1 can be slidably supported by the fixed base 4. In addition, the fixed base 4 may be an arbitrary support member that slidably supports the load detection unit 100A on the base. Any sliding mechanism can be used between the fixed base 4 and the movable base 1.

  In order to make the movement of the movable base 1 relative to the fixed base 4 smoother, a sliding layer may be provided on the lower surface of the movable base 1 and the upper surface of the fixed base 4. The sliding layer can be formed of, for example, polytetrafluoroethylene (PTFE).

  In the load detector 100 of the first embodiment, the center point O of rotation of the load detector 100A is the outer side of the moving base 1, the mounting portion 3 and the fixed base 4 of the load detector 100 as shown in FIG. More specifically, the load detector 100A and the placement unit 3 are defined in front of the load detector 100A, but the present invention is not limited thereto.

The center point of rotation of the load detecting unit 100A can be defined at various positions. For example, as shown in FIG. 7A, the center point O ₁ can be defined below the slope 13 of the moving base 1. Good. In this case, the load detection unit 100A, as shown by the broken line in FIG. 7 (a), rotates around the center point _{O 1.} According to the load detector 100 in which the load detection unit 100A rotates in this way, the extending direction of the load detection unit 100A in the front-rear direction can be changed without greatly changing the position of the slope 13.

As another example, as illustrated in FIG. 7B, the center point O ₂ may be defined below the placement plate 31 of the placement unit 3 (substantially the center of the load detection unit 100A). In this case, the load detection unit 100A, as shown by the broken line in FIG. 7 (b), rotates around the center point _{O 2.} According to the load detector 100 in which the load detection unit 100A rotates in this way, the load detection unit 100A rotates in a substantially fixed position. Therefore, it is possible to reduce the size of the load detector 100 by reducing the fixed base 4. it can.

As another example, as shown in FIG. 7C, the center point O ₃ may be defined outside the fixed base 4 and behind the load detector 100 </ b> A and the placement unit 3. In this case, this case, the load detection unit 100A, as shown by the broken line in FIG. 7 (c), rotated about the center point O _3. According to the load detector 100 in which the load detection unit 100A rotates in this way, the direction in which the load detection unit 100A extends in the front-rear direction can be changed, and the position of the slope 13 can be moved greatly.

7A to 7C, for example, the guide grooves 131 and 132 of the movable base 1 and the guide rails 411 and 412 of the fixed base 4 are moved to the center points O ₁ and O, respectively. _{2. It} can be realized by forming a shape along the circumference centered on O ₃ . Alternatively, it can be realized by connecting the movable base 1 to the fixed base 4 so as to be rotatable by rivets or the like at the center points O ₁ , O ₂ , O ₃ .

  In the load detector 100A of the load detector 100, the first and second load cells 21 and 22 are arranged in parallel to each other, but the first and second load cells 21 and 22 are inclined by about 5 ° with respect to each other. It may be extended.

  In the load detector 100A of the load detector 100, the first and second support bases 11 and 12 of the moving base 1 are provided at the same position in the front-rear direction, whereby the first and second load cells 21 and 22 You may support a cantilever so that a free end may face the same direction. Also in this case, the first and second connection portions 331 and 332 of the placement unit 3 are connected to the vicinity of the free ends of the first and second load cells 21 and 22, respectively.

  In the load detector 100, either the strain gauge 21g of the first beam type load cell 21 or the strain gauge 22g of the second beam type load cell 22 may be omitted. In this case, the load cell from which the strain gauge is omitted substantially functions as a beam member made of a strain generating body, not a load cell.

  In this case, since the proportion of strain generated in the strain generating bodies 21s and 22s varies depending on the mounting position of the subject on the mounting plate 31 of the mounting unit 3, the first and second beam shapes functioning as load cells. The detection value detected by one of the load cells 21 and 22 (here, described as the first beam type load cell 21) also varies depending on the mounting position of the subject. However, if the mounting position of the subject is constant during detection, the first beam type load cell 21 (load detection unit 100A) can accurately detect the variation rate of the load value.

  In the load detector 100, a restriction concave portion that is recessed from the upper surface of the placement plate 31 of the placement portion 3 is provided, and the caster is disposed on or near the line segment L connecting the attachment center C <b> 1 and the attachment center C <b> 2 by the restriction concave portion. May be. Further, the position of the restricting recess is not limited to the line segment L, and is a position on or near the line segment connecting the vicinity of the free end of the first beam type load cell 21 and the vicinity of the free end of the second beam type load cell. Also good. In the present specification and the present invention, the movement of the subject is controlled by contact with the subject such as the short wall 323 or the restriction recess, thereby the subject is placed on or near the line segment L, the first beam type load cell 21. A portion disposed on or in the vicinity of the line segment connecting the vicinity of the free end and the vicinity of the free end of the second beam type load cell is referred to as a “regulator”.

  The movement base 1 of the load detection unit 100 </ b> A may not have the slope 13. In this case, a slope may be fixed to the front edge of the placement plate 31 of the placement unit 3. The slope fixed to the front edge of the mounting plate 31 is configured such that the lower end thereof does not contact the fixed base 4 or the floor during measurement.

  In the load detector 100 of the first embodiment, the load detector 100A may be a single load cell load detector as shown in FIG.

  The moving base 1 or the fixed base 4 may be provided with a lock mechanism for prohibiting the movement of the moving base 1. Moreover, the movable base 1 and the fixed base 4 may be configured to be separable or may not be separable.

  In the description of the above-described embodiment and the modification thereof, the case where the caster attached to the leg portion of the bed is placed on the placement portion 3 has been described as an example, but the load of the present embodiment and the modification is described. According to the detector, the direction in which the load detection unit 100A extends in the front-rear direction can be easily changed, and any other subject including a rolling element and a sliding body can be easily placed on the placement unit 3. .

Second Embodiment
A load detection system 500 according to the second embodiment will be described with reference to FIG.

  The load detection system 500 mainly includes four load detectors 100 and a controller CONT. The four load detectors 100 and the controller CONT are connected by wiring.

  When using the load detection system 500, the casters CT attached to the four legs of the bed BD are respectively placed on the placement portions 3 of the four load detectors 100 (FIG. 8). Thereby, each of the four load detectors 100 detects a part of the test subject's load on the bed BD applied via the leg of the bed BD.

  The controller CONT connected to the four load detectors 100 calculates the load of the subject based on the output from the first beam type load cell 21 and the output from the second beam type load cell 22 of each load detector 100. . Further, any other processing may be performed by the controller CONT.

  Since the load detection system of the present embodiment uses the load detector 100 of the first embodiment, the same effects as the load detector 100 of the first embodiment can be obtained. In particular, the load detection unit 100A that can rotate around the center point O is rotated to easily match the direction in which the load detection unit 100A extends in the front-rear direction with the traveling direction of the caster CT. The operation of placing the detectors 100 at the same time on each of the detectors 100 can be easily performed.

  In the load detection system of the present embodiment, the number of load detectors 100 is not limited to four, and may be three or less, or five or more.

  In the load detection system of the present embodiment, the output from the load detector 100 may be transmitted to the controller CONT by radio instead of wiring. The controller CONT may be connected to a display for displaying the load determined by the controller CONT and an alarm for performing predetermined notification based on the determined load.

  As long as the characteristics of the present invention are maintained, the present invention is not limited to the above embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

  According to the load detector and the load detection system of the present invention, the load detection unit is rotated so that the extending direction in the front-rear direction coincides with the traveling direction of the subject such as a caster, and the subject such as a caster is easily mounted. It can be placed on a table. Therefore, when this is used in a hospital, a nursing facility, etc., the load detector can be easily arranged with a small number of people under the bed or the like, which can contribute to an improvement in the efficiency of medical treatment or nursing care.

DESCRIPTION OF SYMBOLS 1 Moving base, 13 Slope, 141,142 Guide groove, 21 1st beam type load cell, 22 2nd beam type load cell, 3 Mounting part, 31 Mounting plate, 32 Wall part, 4 Fixed base, 411, 412 Guide rail , 100 load detector, 100A load detector, 500 load detection system, O, O ₁ , O ₂ , O ₃ center point

Claims (7)

A moving base, a first beam-type load cell having a free end by being cantilevered on the moving base, and a mounting on which the subject is mounted and connected to the free end of the first beam-type load cell A load detector having a portion;
A load detector comprising a fixed base that supports the load detector so as to be rotatable around a predetermined center of rotation. The subject is a rolling element that rolls from the front to the rear along the first direction and is placed on the mounting portion.
2. The load detector according to claim 1, wherein the predetermined center of rotation is located outside the fixed base and in front of the mounting portion in the first direction. The load detection unit further includes a second beam-type load cell having a free end by being cantilevered on the moving base,
The mounting portion further includes a first connection portion connected to the first beam-type load cell and a second connection portion connected to the second beam-type load cell, and the first beam-type load cell and the second beam-type load cell. Are installed between the beam-type load cells
The first connecting portion of the mounting portion is connected to the first beam-type load cell on the free end side of the first beam-type load cell, and the second connecting portion of the mounting portion is connected to the second beam-type load cell. The load detector according to claim 1, wherein the load detector is connected on the free end side of the second beam-type load cell.   The load detector according to claim 3, wherein the free end of the first beam-type load cell and the free end of the second beam-type load cell are directed to opposite sides.   The placement unit is a regulation unit that regulates the movement of the subject, and the subject whose movement is regulated by the regulation unit includes the vicinity of the free end of the first beam-type load cell and the second beam-type load cell. 5. The load detector according to claim 3, further comprising a restricting portion provided so as to be positioned on a line segment that connects the vicinity of the free end of the first and second free ends.   Furthermore, it has the slope which is fixed to the said movement base part and guides the said subject on the mounting part mentioned above, or is fixed to the said mounting part, and guides the said subject on said mounting part. The load detector according to any one of 5. A load detection system for detecting the load of a subject on a bed,
A plurality of load detectors according to any one of claims 1 to 6 arranged under a caster on a bed leg;
A load detection system having a control unit connected to the plurality of load detectors and calculating the load of the subject based on the output of the load detectors.

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