JP2018091673A - Load detector and load detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load detector that is usable for subjects of various sizes and is compact.SOLUTION: A load detector comprises a first beam-shaped strain generating body, a second beam-shaped strain generating element arranged facing the first beam-shaped strain generating body, a placement unit having a first connection part and a second connection part and provided between the first beam-shaped strain generating body and the second beam-shaped strain generating body, and a strain gauge attached to at least one of the beam-shaped strain generating bodies. The first and second connection parts of the placement unit are connected to the free end of each beam-shaped strain generating body, respectively. The placement unit has a first placement part on which at least one of subjects is placed and a second placement part on which at least some other of the subjects are placed, the first placement part and the second placement part being connected so as to be able to move relatively in a direction in which the first beam-shaped strain generating body and the second beam-shaped strain generating body face each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a load detector including a beam-type load cell and a load detection system including the load detector.

  As a method of managing patients and residents in hospitals and nursing homes, etc., the load applied to the bed is detected, and based on this, it is determined whether there are patients and residents on the bed, and patients on the bed And methods for measuring the respiratory rate and pulse rate of residents are known.

  Patent Document 1 discloses a biological physiology detection device that obtains a subject's respiratory rate and pulse rate based on a load fluctuation state measured by a load measuring means disposed under a leg of a bed. In Patent Document 2, as a load detector that can be arranged 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. 4883380 Japanese Patent No. 4829020

  A caster for facilitating movement is generally provided on a leg portion of a bed used in a hospital or a care facility, and a caster width (a dimension of the caster in the rotation axis direction) is different for each bed. Therefore, if it is intended to provide a load detector with high versatility that can be used with various beds, the size of the weighing pan has to be increased, and as a result, the load detector itself is increased in size.

  Therefore, an object of the present invention is to provide a compact load detector that can be used for subjects having various dimensions.

According to the first aspect of the present invention,
A first beam-shaped strain body having a free end by being cantilevered on a first support;
A second beam-shaped straining body disposed opposite to the first beam-shaped straining body and having a free end by being cantilevered on a second support;
A mounting unit on which a subject is mounted, the first connecting unit connected to the first beam-shaped strain body and the second connecting unit connected to the second beam-shaped strain body. And at least one of the mounting portion provided between the first beam-shaped strain generator and the second beam-shaped strain body, and the first beam-shaped strain body and the second beam-shaped strain body. A load detector comprising a strain gauge attached to the
In the direction in which the first beam-shaped strain body extends, the free end of the second beam-shaped strain body is located on the opposite side of the free end of the first beam-shaped strain body. ,
The first connecting part of the mounting part is connected to the first beam-shaped straining body on the free end side of the first beam-shaped straining body, and the second connecting part of the mounting part is a second connecting part. The beam-type strain body is connected to the free end side of the second beam-shape strain body,
The placement unit has a first connection part and a first placement part and a second connection part on which at least a part of the subject is placed, and at least another part of the subject is placed A second placement portion to be placed;
The first mounting portion and the second mounting portion are provided with a load detector in which the first beam-shaped strain body and the second beam-shaped strain body are connected so as to be movable relative to each other. Is done.

  In the load detector according to the first aspect, the first placement unit includes a first placement plate on which at least a part of the subject is placed, and a first guide for guiding the at least part to the first placement plate. A second placement unit, the second placement plate on which at least another part of the subject is placed, and the at least another part on the second placement plate. You may have the 2nd slope to guide.

  In the load detector according to the first aspect, at least one of the first slope and the second slope has a first position in which a tip portion is in contact with an installation surface on which the load detector is installed with a predetermined peristaltic axis as a center. The tip may be swingable between a second position spaced from the installation surface.

  In the load detector according to the first aspect, the mounting portion extends from at least one of the first slope and the second slope that can be swung to the side opposite to the tip portion with respect to the peristaltic shaft. A lever may be further included.

According to the second aspect of the present invention,
A first beam-shaped strain body having a free end by being cantilevered on a first support;
A second beam-shaped strain body extending at an angle with respect to the first beam-shaped strain body and having a free end by being cantilevered on a second support base;
A mounting unit on which a subject is mounted, the first connecting unit connected to the first beam-shaped strain body and the second connecting unit connected to the second beam-shaped strain body. A placing portion provided between the first beam-shaped strain body and the second beam-shaped strain body,
A load detector comprising a strain gauge attached to at least one of the first beam-shaped strain body and the second beam-shaped strain body,
In the direction of the bisector of the angle defined between the extending direction of the first beam-shaped strained body and the extending direction of the second beam-shaped strained body, the first beam-shaped strained body The free end of the body is on the free end side of the second beam-shaped strain body, and the fixed end of the first beam-shaped strain body is on the fixed end side of the second beam-shaped strain body,
The distance between the free end of the first beam-type strainer and the free end of the second beam-type strainer is such that the fixed end of the first beam-type strainer and the second beam shape Greater than the distance between the fixed end of the strain body,
The first connecting portion of the first mounting portion is connected to the first beam-shaped strain generating body on the free end side of the first beam-shaped strain generating body, and the second connecting portion of the second mounting portion is the first connecting portion. Connected to the free end side of the second beam-shaped strain body and the second beam-shaped strain body,
The placement unit has a first connection part and a first placement part and a second connection part on which at least a part of the subject is placed, and at least another part of the subject is placed A second placement portion to be placed;
The first mounting portion and the second mounting portion are formed with the angle defined between the extending direction of the first beam-shaped strained body and the extending direction of the second beam-shaped strained body. A load detector is provided that is coupled to be movable relative to the direction of magnitude change.

  In the load detector according to the second aspect, the first placement unit includes a first placement plate on which at least a part of the subject is placed, and a first guide for guiding the at least part to the first placement plate. A second placement unit, the second placement plate on which at least another part of the subject is placed, and the at least another part on the second placement plate. You may have the 2nd slope to guide.

  In the load detector according to the first and second aspects, the first mounting portion has a first side wall that is adjacent to the first beam-shaped strained body and extends along the first beam-shaped strained body. Alternatively, the second placement unit may have a second side wall that is adjacent to the second beam-shaped strain body and extends along the second beam-shaped strain body.

  In the load detector according to the first and second aspects, the strain gauge may be attached to both the first beam-shaped strain body and the second beam-shaped strain body. In addition, the first placement unit may be provided with a first movement restriction unit that restricts movement of at least a part of the subject, and the second placement unit includes at least another part of the subject. A second movement restriction unit that restricts movement may be provided.

According to a third aspect of the invention,
A load detection system for detecting the load of a subject on a bed,
A plurality of load detectors of the first and / or second aspects disposed 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.

  The load detector of the present invention can be used for subjects of various sizes and is compact.

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 exploded perspective view of the placement unit. FIG. 4 is an explanatory view for explaining a method of placing a caster on the placement unit. FIG. 4A shows a state in which a relatively narrow caster is placed on the placement unit in the closed state. (B) shows a state in which a relatively wide caster is placed on a fully open placement part. FIG. 5 is a schematic plan view of a load detector having one beam-type load cell. FIG. 6 is an explanatory diagram showing distances in the front-rear direction and the width direction between the position of the subject placed on the placement unit and the mounting position of the placement unit on the load cell. 7A and 7B are plan views of the load detector according to the second embodiment of the present invention, in which FIG. 7A shows the placement part in the closed state, and FIG. 7B shows the placement part in the fully open state. Indicates. FIG. 8 is a plan view of a mounting unit according to a modified example. FIG. 8A shows the mounting unit in the closed state, and FIG. 8B shows the mounting unit in the fully opened state. FIG. 9 is a perspective view showing a part of a mounting portion of a modified example having a movable slope. 10A and 10B are explanatory diagrams for explaining the operation of the movable slope attached to the mounting portion. FIG. 10A shows a state where the lower end of the movable slope is in contact with the floor surface, and FIG. 10B shows the movable slope. The state where the lower end of is separated from the floor surface is shown. FIG. 11 is a schematic diagram showing a configuration of a load detection system according to the third embodiment of the present invention.

<First Embodiment>
With reference to FIGS. 1-6, the load detector 100 of 1st Embodiment of this invention is demonstrated. In the following, casters (not shown) attached to the lower ends of four legs of a bed (not shown) to detect the magnitude of the load value of the subject on the bed and fluctuations in the load value are placed on the placement unit 3. Although the case where it detects by mounting on (after-mentioned) is demonstrated as an example, a test subject is not restricted to a caster, Other arbitrary rolling elements, a sliding body, etc. may be sufficient.

  As shown in FIGS. 1 and 2, the load detector 100 according to the first embodiment is a first and second base portions 11 and 12, and a first cantilevered in parallel by the first and second base portions 11 and 12. , Second beam type load cells 21, 22, and mounting unit 3 that is supported by first and second beam type load cells 21, 22 so as to be finely movable in the vertical direction and has slope 33.

  In the following description, the extending direction of the first and second beam-type load cells 21 and 22 is the front-rear direction of the load detector 100, the side where the slope 33 is located is the front side, and the opposite side is the rear side. The direction in which the first and second beam type load cells 21 and 22 face each other is the width direction of the load detector 100.

  The first and second bases 11 and 12 are respectively flat plate portions 11a and 12a that are long flat plates extending in the front-rear direction, and box-shaped support base portions 11b and 12b provided on the upper surfaces of the flat plate portions 11a and 12a. And have. The support base part 11b is provided at the rear end of the flat plate part 11a, and the support base part 12b is provided at the front end of the flat plate part 12a.

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

  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 lower surface in the vicinity of the rear end of the strain generating body 21s is fixed to the support base portion 11b of the first base portion 11, thereby the first base portion 11 (support base portion) having the rear end as a fixed end 21s1 and the front end as a free end 21s2. 11b) is cantilevered. On the other hand, the lower surface in the vicinity of the front end of the strain generating body 22s is fixed to the support base 12b of the second base 12, so that the front end is the fixed end 22s1, and the rear end is the free end 22s2. The support base 12b) is cantilevered. 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. Accordingly, the support base portion 11b of the first base portion 11 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 portion 12b of the second base portion 12 is in contact with the free end 21s2 of the strain body 21s. It is in almost the same position.

The placement unit 3 is a weighing pan on which a caster (subject) attached to the leg of the bed is placed, and is slidable as shown in FIGS. 3, 4 (a) and 4 (b). Including a first portion 3 _i and a second portion 3 _ii connected to each other.

The first portion _{3 i} includes the first mounting plate 31 _i flat rectangular, and the side wall 321 _i and the first stop wall 323 _i upstanding from the first mounting plate 31 _i, the first loading plate It mainly includes a first slope portion 33 _i extending obliquely from 31 _i . The first side wall 321 _i has a first connecting portion 34 _i for connecting the first portion 3 _i (mounting portion 3) to the first beam-type load cell 21, and the first mounting plate 31 _i includes A connection plate 35 _i for connecting (linking) the first part 3 _i and the second part 3 _ii is fixed. In FIG. 3, in order to clearly show that the first mounting plate 31 _i and the connection plate 35 _i are displaced in the thickness direction, the first slope portion 33 _i is drawn with a broken line, and this is seen through. doing.

The first side wall 321 _i is provided over the entire long side along one long side of the first placement plate 31 _i , and the first stop wall portion 323 _i is provided in the first placement plate 31 _i. Along one of the short sides, the entire short side is provided.

The first slope portion 33 _i is provided on the short side of the first placement plate 31 _i opposite to the short side on which the first stop wall portion 323 _i is provided. The first slope portion 33 _i is a state in which the subject on the platform 3 is placed (i.e., the state in the detection load of subjects) even at the lower end of the first slope portion 33 _i (tip) of the load It is comprised so that it may not contact the installation surface (floor surface) in which the detector 100 was installed.

The first connecting portion 34 _i is fixed to the outer surface of the first side wall 321 _i at the end portion close to the first slope portion 33 _i (the surface facing the first mounting plate 31 _i side). It is a flat plate parallel to the first placement plate 31 _i .

The connection plate 35 _i is a rectangular flat plate, the length in the long side direction is equal to the length in the long side direction of the first placement plate 31 _i , and the length in the short side direction is the first placement plate 31 _i. It is larger than the length in the short side direction. The connection plate 35 _i is provided with two slits s extending in the short side direction and spaced apart in the long side direction. The number of slits s may be one or three or more.

The connection plate 35 _i has the long side direction aligned with the long side direction of the first placement plate 31 _i and the upper surface thereof is flush with the lower surface of the first placement plate 31 _i. The mounting plate 31 _i is fixed to the long side where the first side wall 321 _i is not provided.

The second portion _{3 ii} includes a second mounting plate _{31 ii} flat rectangular, and the side wall _{322 ii} and second restraining wall portion _{323 ii} upstanding from the second mounting plate _{31 ii,} the second loading plate It mainly includes a second slope portion 33 _ii extending obliquely from 31 _ii . Further, a second connecting portion 34 _ii for connecting the second portion 3 _ii (mounting portion 3) to the second beam type load cell 22 is fixed to the second side wall 322 _ii .

The dimension in the long side direction of the second mounting plate 31 _ii is equal to the dimension in the long side direction of the first mounting plate 31 _i and the connection plate 35 _i . On the other hand, the dimension in the short side direction of the second mounting plate 31 _ii is larger than the dimension in the short side direction of the first mounting plate 31 _i and the connection plate 35 _ii . The thickness of the second mounting plate 31 _ii is equal to the thickness of the first mounting plate 31 _i . The lower surface of the one long side near the second mounting plate 31 _ii, are provided screw holes h are two. The number of screw holes h corresponds to the number of slits s, and may be one or three or more.

The second side wall 322 _ii is provided in the entire area of the second mounting plate 31 _ii along the long side opposite to the long side where the screw hole h is provided in the vicinity. The second stop wall portion 323 _ii is provided on the entire short side along one short side of the second mounting plate 31 _ii .

The second slope portion 33 _ii is provided on the short side of the second mounting plate 31 _ii opposite to the short side on which the second stop wall portion 323 _ii is provided, and the first slope portion 33 _i Similarly, even when the subject is placed on the placement unit 3, the lower end of the second slope portion 33 _ii is configured not to contact the installation surface on which the load detector 100 is installed.

The second connecting portion 34 _ii was fixed to the outer surface of the second side wall 322 _ii at the end close to the second stop wall 323 _ii (the surface facing the side opposite to the second mounting plate 31 _ii side). a parallel flat plate and the first mounting plate _{31 ii.}

The first part 3 _i and the second part 3 _ii are slidably and integrally connected (coupled) to form the placement unit 3. Specifically, for example, on the connecting plate 35 _i of the first portion _{3 i} overlapping the second mounting plate _{31 ii} of the second portion _{3 ii,} from the lower connection plate 35 _i, the connection pin cp, slit Screw into the screw hole h through s. Accordingly, the first portion 3 _i and the second portion 3 _ii are slidable in the direction in which the slit s extends (that is, the short side direction of the first mounting plate 31 _i and the second mounting plate 31 _ii ). Connected.

In a state where the first portion 3 _i and the second portion 3 _ii are connected, the upper surface of the first mounting plate 31 _{i and} the upper surface of the second mounting plate 31 _ii are flush with each other, and the first blocking wall 323 _i The inner surface (the surface facing the first mounting plate 31 _i side) and the inner surface of the second stop wall 323 _ii (the surface facing the second mounting plate 31 _ii side) are flush with each other, and the upper surface of the first slope portion 33 _i And the upper surface of the second slope portion 33 _ii are flush with each other.

The first and second connecting portions 34 _i and 34 _ii of the mounting portion 3 are respectively connected to the lower surfaces of the first and second beam-type load cells 21 and 22 near the free ends 21 s 2 and 22 s 2 of the strain generating bodies 21 s and 22 s. ing. In a state in which the placement unit 3 is connected to the first and second beam-type load cells 21 and 22, the first and second side walls 321 _i and 322 _ii of the placement unit 3 are the first and second beam types, respectively. Adjacent to the load cells 21, 22, it extends in the front-rear direction along the first and second beam-type load cells 21, 22. The short side direction of the first and second mounting plates 31 _i and 31 _ii , that is, the direction in which the first portion 3 _i and the second portion 3 _ii slide is the same as the width direction of the load detector 100.

  The load detector 100 and the placement unit 3 are deformed as follows to change the dimension in the width direction.

The connection pin cp attached to the second portion 3 _ii of the placement portion 3 is in contact with the end portion on the first placement plate 31 _i side of the slit s provided in the first portion 3 _i (see FIG. 4 (a)), the first mounting plate 31 _i and the second mounting plate 31 _ii are in contact with each other to define a rectangular mounting plate 31, and the first stop wall 323 _i The second stop wall 323 _ii is in contact with each other to define a continuous stop wall 323, and the first slope portion 33 _i and the second slope portion 33 _ii are in contact with each other to define a continuous slope 33. doing. Hereinafter, this state is referred to as a closed state of the load detector 100 and the placement unit 3. When the load detector 100 and the placement unit 3 are in the closed state, the width of the placement plate 31 (the dimension in the width direction between the first side wall 321 _i and the second side wall 322 _ii ) is minimized.

On the other hand, in a state where the connection pin cp is in contact with the end of the slit s opposite to the first mounting plate 31 _i (FIG. 4B), the first mounting plate 31 _i and the first mounting plate 31 _i The two mounting plates 31 _ii define a mounting plate 31 that is spaced apart from each other in the width direction, and the first stopping wall 323 _i and the second stopping wall 323 _ii include the stopping walls 323 that are spaced from each other in the width direction. The first slope portion 33 _i and the second slope portion 33 _ii define a slope 33 that is spaced apart from each other in the width direction. Hereinafter, this state is referred to as a fully opened state of the load detector 100 and the placement unit 3. When the load detector 100 and the placement unit 3 are in the fully open state, the width of the placement plate 31 is maximized.

  Next, the usage method of the load detector 100 of this embodiment is 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, the following procedure is followed.

  First, after adjusting the width of the mounting portion 3 according to the width of the caster, the load detector 100 is disposed in the vicinity of each of the four casters. As an example, when the caster attached to the bed is a single-wheel caster CT1 as shown in FIG. 4A, the load detector 100 in which the placement unit 3 is closed is disposed. On the other hand, when the caster attached to the bed is a twin-wheel caster CT2 as shown in FIG. 4B, the load detector 100 in which the placement unit 3 is fully opened is disposed. In addition, according to the width | variety of a caster, it is good also considering the mounting part 3 as the arbitrary states (henceforth an "open state") between the full open states of a closed state.

  Both the single-wheel caster CT1 and the twin-wheel caster CT2 are guided by the slope 33 of the mounting portion 3 to reach the mounting plate 31 and come into contact with the stop wall 323 and stop on the mounting plate 31. (Casters CT1, CT2 indicated by broken lines in the figure).

The first and second side walls 321 _i , 322 have a slight gap between the casters CT1 and CT2 and the side surfaces of the casters CT1 and CT2 on both sides in the width direction of the casters CT1 and CT2 placed on the placement plate 31. _ii is located. Accordingly, the casters CT1 and CT2 have only a slight change in posture (in other words, a change in the traveling direction, or rotation of the casters CT1 and CT2 around the vertical axis). , In contact with at least one of the second side walls 321 _i and 322 _ii . This contact suppresses changes in the postures of the casters CT1 and CT2. Suppressing the change in the posture of the casters CT1 and CT2 placed on the placement plate 31 leads to error suppression in load detection.

  In addition, in the mounting part 3 in the fully open state and the open state, the mounting plate 31, the blocking wall 323, and the slope 33 are all configured by two parts that are separated in the width direction, and the center part in the width direction. However, there is no mounting plate 31, stop wall 323 and slope 33, but the two-wheel caster CT2 is also composed of two casters (wheels) spaced apart in the width direction. There is no part. Therefore, the absence of the mounting plate 31, the restraining wall 323 and the slope 33 in the center in the width direction means that when the two-wheel caster is mounted on the mounting unit 3, the mounting ease and the detection result The detection accuracy is not affected. In addition, when the caster is a single wheel, the placement unit 3 may be fully open or open. In this case, the caster is not provided in a portion where the placement plate 31 or the like at the center in the width direction of the placement unit 3 is not present. It is desirable that there is no fear of insertion. This is because the influence on the ease of placement and the detection result is avoided.

  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 FIGS. 4A and 4B, the placement unit 3 is placed on the placement plate 31 in any of the closed state, the open state, and the fully open state. Are connected to the strain generating bodies 21s and 22s of the first and second beam-type load cells 21 and 22 via the first and second connecting portions 34 _i and 34 _ii at the diagonal positions.

Here, assuming that the center point of attachment of the first connecting portion 34 _{i to} the strain generating body 21 s is the attachment center C 1, and the center point of attachment of the second connection portion 34 _{ii to} the strain generating body 22 s is the attachment center C 2, The placement plate 31 of the placement portion 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 arranging the casters CT1 and CT2 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 unit 3. In the load detector 100 of the present embodiment, the restraining wall 323 is arranged so that the casters CT1 and CT2 that are in contact with the restraining wall 323 are positioned on the line segment L. Moreover, you may arrange | position the stop wall 323 so that the gravity center of caster CT1 and CT2 which contacted the stop wall 323 may be located on the line segment L. FIG.

  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 this embodiment, as shown in FIG. 6, before and after the mounting position P and the mounting center C1 of the subject mounted on the mounting plate 31 of the mounting unit 3 the distance in the direction of the _{x P1,} the distance in the longitudinal direction between the loading position P and the mounting center C2 When _{x P2,} the sum of _{x P1} and _{x P2} are substantially the entire area of the mounting plate 31 of the platform 3 It becomes constant at. 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. Further, this relationship holds even if the width of the mounting plate 31 changes. 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. Further, this relationship holds even if the width of the mounting plate 31 changes. 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.

  The load detector 100 according to the present embodiment has a placement unit 3 that can be deformed between a fully open state and a closed state, and a subject such as a caster is placed by deforming the placement unit 3. It is possible to change the width of the mounting plate 31 and thus the width of the load detector 100. Accordingly, the width of the mounting plate 31 can be adjusted to be used for casters (subjects) of various widths such as single wheel casters and twin wheel casters, and the mounting unit 3 and the load detector 100 are closed when not in use. The load detector 100 can be made compact.

In the placement unit 3 included in the load detector 100 of the present embodiment, first and second side walls 321 _i and 322 _ii are provided on both sides in the width direction of the placement plate 31. Therefore, the width of the mounting plate 31 is changed according to the width of the subject caster, and the first and second side walls 321 _i , 322 _ii are located in the vicinity of both sides of the caster mounted on the mounting plate 31. if you adjusted to be the first, suppressing a change in the attitude of the caster CT by the second sidewall ₃₂₁ i, _{322 ii.} That is, according to the load detector 100 of the present embodiment, by simply adjusting the width of the mounting plate 31 according to the width of the caster, the load of the caster having various widths can be changed in a state in which the posture change is suppressed, and thus Detection is possible in a state in which measurement errors are suppressed.

Second Embodiment

  The load detector 200 according to the second embodiment includes first and second base portions 11 and 12 and first and second beam-type load cells 21 and 22 that are cantilevered by the first and second base portions 11 and 12. However, the relative arrangement relationship between the first beam type load cell 21 and the second beam type load cell 22 is the same as that of the load detector 100 of the first embodiment. Unlike the arrangement relationship of the second beam type load cells 21, 22, the placement unit 4 is included instead of the placement unit 3.

  Hereinafter, with reference to FIG. 7A and FIG. 7B, the load detector 200 of the second embodiment will be described focusing on differences from the load detector 100 of the first embodiment.

The mounting portion 4 included in the load detector 200 of the second embodiment has a shape obtained by substantially bending the mounting portion 3 of the first embodiment into a fan shape, as shown in FIGS. As shown in b), it includes a first part 4 _i and a second part 4 _ii slidably connected.

The first portion _{4 i} is a first loading plate 41 _i fan tabular having a center _{O 41i,} a first side wall 421 _i upstanding from the first mounting plate 41 _i, the first mounting plate 41 _i The first slope portion 43 _i extending mainly is included. The first side wall 421 _i has a first connecting portion 44 _i for connecting the first portion 4 _i (mounting portion 4) to the first beam type load cell 21, and the first mounting plate 41 _i includes A connection plate 45 _i for connecting the first part 4 _i and the second part 4 _ii is fixed.

The first side wall 421 _i is provided over the entire area of the first placement plate 41 _i along one of the pair of radially extending sides, and the first slope portion 43 _i is formed on the first mounting plate 41 _i. Along the arcuate side on the outer peripheral side of the mounting plate 41 _i , it is provided over the entire arcuate side.

The first connecting portion 44 _i is fixed to the outer surface of the first side wall 421 _i on the outer peripheral side from the center portion (the surface facing the side opposite to the first mounting plate 41 _i side). It is a flat plate parallel to _i .

Connecting plate 45 _i is a sector flat plate having a circumferential length the same shape as the first mounting plate 41 _i, except longer points to than the length in the circumferential direction of the first mounting plate 41 _i. The connection plate 45 _i is provided with two slits s extending in the circumferential direction so as to be separated from each other in the radial direction. The number of slits s may be one or three or more.

Connecting plate 45 _i, the center _{O 45i} matches the center _{O 41i} of the first mounting plate 41 _i, and in a state where the upper surface and the lower surface flush with the first mounting plate 41 _i, the first mounting The mounting plate 41 _i is fixed to the side opposite to the side where the first side wall 421 _i is provided.

The second part _{4 ii} is a second mounting plate _{41 ii} fan tabular having a center _{O 41Ii,} a second sidewall _{422 ii} upstanding from the second mounting plate _{41 ii,} the second mounting plate _{41 ii} It mainly includes a second slope portion 43 _ii that extends. Further, a second connecting portion 44 _ii for connecting the second portion 4 _ii (mounting portion 4) to the second beam type load cell 22 is fixed to the second side wall 422 _ii .

The second mounting plate 41 _ii has the first mounting plate 41 _i and the connection plate 45 _i except that the circumferential length is longer than the circumferential length of the first mounting plate 41 _i and the connection plate 45 _i. Have the same shape. The thickness of the second mounting plate 41 _ii is equal to the thickness of the first mounting plate 41 _i . Two screw holes h are provided on the lower surface of the second mounting plate 41 _ii in the vicinity of one of the pair of sides extending in the radial direction. The number of screw holes h corresponds to the number of slits s, and may be one or three or more.

The second side wall 422 _ii is provided over the entire side of the second mounting plate 41 _ii along the side opposite to the side where the screw hole h is provided in the vicinity. 43 _ii along the outer periphery of the arcuate edge of the second mounting plate 41 _ii, is provided on the entire area of the arcuate sides.

The second connecting portion 44 _ii is a second mounting plate fixed to the outer surface of the second side wall 422 _ii on the outer peripheral side of the central portion (the surface facing the side opposite to the second mounting plate 41 _ii side). 41 is a flat plate parallel to _ii .

The first part _{4 i} and the second part _{4 ii,} slidably connected with the center _{O 41i} and a state of being matched with the center _{O 41Ii} the second mounting plate _{41 ii} of the first mounting plate 41 _i The mounting unit 4 is configured. The connection between the first part 4 _i and the second part 4 _ii is, for example, similar to the connection between the first part 3 _i and the second part 3 _ii in the load detector 100 according to the first embodiment. Can be used.

In a state where the first portion 4 _i and the second portion 4 _ii are connected, the upper surface of the first mounting plate 41 _{i and} the upper surface of the second mounting plate 41 _ii are flush with each other. Further, the upper surface of the first slope portion 43 _{i and} the upper surface of the second slope portion 43 _ii are flush with each other.

The first beam type load cell 21 cantilevered by the first base portion 11 has an extending direction of the first beam type load cell 21 and an extending direction of the first side wall 421 _i of the first portion 4 _i of the mounting portion 4. It arrange | positions adjacent to the mounting part 4 so that it may correspond. The first connecting portion 44 _i of the mounting portion 4 is connected to the lower surface near the free end 21 s 2 of the strain body 21 s of the first beam type load cell 21.

The second beam type load cell 22 cantilevered by the second base 12 is such that the extending direction of the second beam type load cell 22 is the extending direction of the second side wall 422 _ii of the second portion 4 _ii of the mounting portion 4. It is arranged adjacent to the placement part 4 so as to match. The second connecting portion 44 _ii of the mounting portion 4 is connected to the lower surface near the free end 22 s 2 of the strain body 22 s of the second beam type load cell 22.

The load detector 200 and the mounting portion 4 are deformed as follows around the centers O _41i , O _41ii , and O _45i to change the dimensions in the circumferential direction.

The connection pin cp attached to the second portion 4 _ii of the placement portion 4 is in contact with the end portion on the first placement plate 41 _i side of the slit s provided in the first portion 4 _i (FIG. 7 (a)), the first mounting plate 41 _i and the second mounting plate 41 _ii are in contact with each other to define a fan-shaped mounting plate 41, and the first slope portion 43 _i and the first mounting plate 41 _i The two slope portions 43 _ii are in contact with each other to define a continuous slope 43. Hereinafter, this state is referred to as a closed state of the load detector 200 and the placement unit 4. When the load detector 200 and the mounting portion 4 are in the closed state, the circumferential dimension of the mounting plate 41 (the interval between the extending direction of the first side wall 421 _{i and} the extending direction of the second side wall 422 _ii is defined. The size of the corners formed is minimal.

On the other hand, when the connection pin cp is in contact with the end of the slit s opposite to the first mounting plate 41 _i side (FIG. 7B), the first mounting plate 41 _i and the first mounting plate 41 _i The two mounting plates 41 _ii define the mounting plates 41 that are spaced apart from each other in the circumferential direction, and the first slope portions 43 _i and the second slope portions 43 _ii define the slopes 43 that are spaced apart from each other in the circumferential direction. It is made. Hereinafter, this state is referred to as a fully opened state of the load detector 200 and the placement unit 4. When the load detector 200 and the placement unit 4 are in the fully open state, the dimension of the placement plate 41 in the circumferential direction is maximized.

  In the state where the first and second beam type load cells 21 and 22 are connected to the placement unit 4, the first and second beam types can be used regardless of whether the placement unit 4 is in the closed state or the fully open state. The load cells 21 and 22 (distortion bodies 21s and 22s) are inclined and extended with respect to each other. In the present specification and the present invention, “an element extends at an incline with respect to another element” means between an extending direction of an element and an extending direction of another element. It means that there is an angle greater than 0 ° and smaller than 180 °.

  Further, in the direction of the angle bisector defined between the extending direction of the first beam-type load cell 21 and the extending direction of the second beam-type load cell 22 (the front-rear direction of the load detector 200), The free ends 21s1, 22s2 of the strain generating bodies 21s, 22s of the first and second beam type load cells 21, 22 face the same side. The distance between the free end 21s2 of the strain body 21s and the free end 22s2 of the strain body 22s is larger than the distance between the fixed end 21s1 of the strain body 21s and the fixed end 22s1 of the strain body 22s.

  The load detector 200 of the second embodiment can also be used similarly to the load detector 100 of the first embodiment. Specifically, for example, when used for a narrow caster such as a single-wheel caster, the mounting portion 4 is used in a closed state as shown in FIG. When using it for a wide caster, the mounting portion 4 is used in a fully open state as shown in FIG.

In any case, the caster reaches the mounting plate 41 through the slope 43, contacts the first and second side walls 421 _i and 422 _ii , and is disposed at an appropriate position on the mounting plate 41. The Specifically, the appropriate position is, for example, a position on the line segment L that connects the connection centers C1 and C2 between the first and second connecting portions 44 _i and 44 _ii and the strain generating bodies 21s and 22s. In use, the caster (preferably its center of gravity) in contact with the first and second side walls 421 _i and 422 _ii on the placement plate 41 is placed in advance according to the width of the caster so as to be positioned on the line segment L. The circumferential dimension of the plate 31 is adjusted.

  Even with the load detector 200 of the second embodiment, the same effect as that of the load detector 100 of the first embodiment can be obtained.

In addition, in the mounting portion 4 included in the load detector 200 of the second embodiment, the mounting plate 41 has a fan shape, and the interval between the front end portions of the first and second side walls 421 _i , 422 _ii (that is, casters) The opening for introduction onto the mounting plate 41 is wide. Therefore, when the traveling direction of the caster is shifted with respect to the front-rear direction of the load detector 200, for example, when the caster is aligned with the extending direction of the first and second beam-type load cells 21, 22, The caster can be easily guided onto the mounting plate 41.

<Modification>
In the load detector 100 and the load detector 200 of the above-described embodiment, the following modification can be adopted.

  In the load detectors 100 and 200 of the first and second embodiments, placement units having various structures can be used instead of the placement units 3 and 4. As an example, the placement unit 5 shown in FIGS. 8A and 8B can be used instead of the placement unit 3 of the load detector 100 of the first embodiment.

The placement unit 5 includes a first portion 5 _i and a second portion 5 _ii . A first loading plate 51 _i first portion _{5 i} are flat convex shape (T-shape) shape, a first side wall 521 _i and the first stop wall _{523 ii} upstanding from the first loading plate 51 _i Have. A second loading plate _{51 ii} second portion _{5 ii} is a flat plate of the recess (U-shaped) shape, the second side wall _{522 ii} and second restraining wall portion _{523 ii} upstanding from the second loading plate _{51 ii} .

In the mounting portion 5 of the modified example, the first and second side walls 521 _i and 522 _ii are opposed to the pair of sides that define the concave portion of the second mounting plate 51 _ii of the second portion 5 _ii , respectively. A slit ss extending in the first portion 5 _i is provided, and a flat plate-like protruding piece pp is provided on each of a pair of opposing sides of the convex portion of the first mounting plate 51 _i of the first portion 5 _i . The projecting piece pp of the first mounting plate 51 _i is slidably fitted in the slit ss of the second mounting plate 51 _ii , so that the first and second portions 5 _i , 5 _ii The first and second side walls 521 _i and 522 _ii are slidably connected in opposite directions.

In the mounting portion 5 of the modified example, the shape of the portion other than the convex portion of the first mounting plate 51 _i and the shape of the convex portion are each fan-shaped, and the second mounting plate 51 _ii is defined as a fan-shaped concave portion. If the fan-shaped flat plate is used, the placement unit 5 can be used in place of the placement unit 4 in the load detector 200 of the second embodiment.

  As another example, instead of the placement units 3 and 4 of the load detectors 100 and 200 according to the first embodiment, a first placement plate on which a part of the subject is placed and the other part of the subject It is possible to use a mounting portion obtained by connecting the second mounting plate on which the is mounted with a telescopic nested cylindrical member. As a modification of the placement units 3 and 4, a mode in which a gap is generated between the first placement plate and the second placement plate in the closed state is not excluded.

  In the placement units 3 and 4 of the first and second embodiments, the amount of displacement from the closed state to the fully open state can be arbitrarily set. Even when the mounting portion 4 of the second embodiment is in a closed state, the first and second beam-type load cells 21 and 22 connected to the mounting portion 4 can be configured not to be parallel.

  In the load detectors 100 and 200 of the first and second embodiments, the load detectors 100 and 200 are fixed to the first base portion 11 and / or the second base portion 12 in place of the slopes 33 and 43 provided in the placement portions 3 and 4. You may have a slope. Such a slope opposes the front edges of the placement plates 31 and 41 of the placement portions 3 and 4 with a gap.

  In the load detector 100 of the first embodiment, the slope 33 of the placement unit 3 is fixed to the placement plate 31, but is not limited thereto. The slope 33 may be swingable with respect to the mounting plate 31.

Specifically, for example, as shown in FIG. 9, the second portion 3 _ii of the placement portion 3 does not have the second slope portion 33 _ii , and instead the guide portion G is attached to the second portion 3 _ii. It may be done. In this case, the second mounting plate 31 _ii may be provided with the concave portion R and the shaft support portion S. Recess R is recess substantially U (U-shaped) shape provided on the top surface of the second mounting plate 31 _ii. Shaft support portion S is a portion of the substantially rectangular parallelepiped was provided et the short side of the second stop wall 323 _ii of the second mounting plate 31 _ii is not provided, on its side surface, a second mounting plate 31 _ii Boss (not shown) protruding on both sides in the short side direction is provided. In FIG. 9, the guide part G is seen through in order to clearly show the shape of the second portion _3ii .

  The guide part G is a plate-like member having a slope part SL and a lever part LV integrally connected to the slope part SL.

  The slope portion SL has a substantially rectangular shape in plan view, and a notch n having a substantially rectangular shape in plan view is defined at the center of the long side (one end) to which the lever portion LV is connected. A pair of opposing surfaces that define the short side of the portion n are each provided with a recess (not shown). The slope portion SL is thicker than the lever portion LV (see FIG. 10), and the slope portion SL is tapered so that the tip (front end, lower end) SLT is thin.

  The lever portion LV includes a first arm portion AM1 and a second arm portion AM2 connected to the long sides of the rectangular slope portion SL at both ends thereof, and a first arm portion AM1 and a first arm portion on the opposite side of the slope portion SL. It has a rectangular part (contact part) RC connected to the two-arm part AM2, and is substantially U-shaped (substantially U-shaped) in plan view.

The guide part G is rotatably attached to the second part _3ii . Specifically, the boss of the shaft support portion S of the second mounting plate 31 _ii is fitted into the concave hole of the notch portion n of the slope portion SL, so that the guide portion G is in contact with the second portion 3 _ii. Thus, it is rotatably connected around a rotation axis X (FIGS. 10A and 10B) connecting the boss and the recessed hole. As described above, the thickness of the slope portion SL and the lever portion LV in the guide portion G is different in the front-rear direction, so that the weight on the front side (the tip SLT side of the slope portion SL) from the concave hole is on the rear side (lever portion LV). It is configured to be heavier than the weight of the side). Therefore, as long as no load is applied to the lever portion LV, the guide portion G rotates about the rotation axis X in the direction in which the tip SLT descends downward, and the tip SLT is in contact with the installation surface. Instead of configuring the slope portion SL so that the weight on the tip SLT side is heavier than the weight on the lever portion LV side, a mechanism for biasing the tip SLT toward the installation surface by a spring, a magnet, or the like may be provided. good.

The planar view shape of the recess R provided in the second mounting plate 31 _ii and the planar view shape of the lever portion LV of the guide portion G are substantially equal, and the guide portion G rotates with respect to the second placement plate 31 _ii . dynamic and, when the lever portion LV of the guide portion G is in contact with the second mounting plate _{31 ii,} lever LV is disposed in the recess R (Figure 10 (b)). At this time, the upper surface of the lever portion LV may become flush with the upper surface of the second mounting plate 31 _ii.

When the caster CT is on the installation surface (floor surface) in front of the second mounting plate 31 _ii , the guide portion G is in a state where the tip SLT of the slope portion SL is in contact with the installation surface (FIG. 10A )). Therefore, the caster CT can easily ride on the slope portion SL without a step. On the other hand, in the state where the caster CT reaches the second mounting plate 31 _ii , the guide portion G is in a state where the tip SLT of the slope portion SL is separated from the installation surface because the caster CT pushes down the lever portion LV. (FIG. 10 (b)). Therefore, no measurement error due to the contact between the guide portion G and the installation surface occurs during load detection.

Similar guide portion G in addition to the second portion _{3 ii,} or in place of the second part _{3 ii,} it may be employed in the first portion _{3 i.} Moreover, the guide part G does not need to have a lever part. In this case, a biasing member such as a torsion spring that biases the tip SLT of the slope part SL in a direction away from the installation surface is mounted on the guide part G. You may provide in a connection part with a mounting plate. When the caster rides up, the caster pushes down the slope portion SL and brings the tip SLT into contact with the installation surface against the biasing force of the biasing member.

In the load detector 100 of the first embodiment, the dimensions of the first placement plate 31 _{i included} in the first portion 3 _i of the placement section 3 and the dimensions of the second placement plate 31 _{ii included} in the second portion 3 _ii. As in the first embodiment, it is not essential to make the dimensions of the first mounting plate 31 _{i different from} the dimensions of the second mounting plate 31 _ii . The same applies to the first and second mounting plates 41 _i and 41 _ii of the second embodiment.

In the mounting portion 3 of the first embodiment, the first blocking wall portion 323 _i and the second blocking wall portion 323 _ii are configured to be nested, and the continuous blocking wall 323 is formed even when the mounting portion 3 is in the open state. It may be defined. The same applies to the first and second slope portions 33 _i and 33 _ii , and the same applies to the mounting portion 4 of the second embodiment.

The placement portion 3 of the first embodiment does not have to include the restraining wall 323, while the placement portion 4 of the second embodiment has the restraining wall that connects the first and second side walls 421 _i and 422 _ii. You may do it. In addition, the placement units 3 and 4 may have restriction recesses on the top surfaces of the placement plates 31 and 41 for restraining the subject to a desired place. A structure provided on the placement portions 3 and 4 to restrain the movement of the subject, such as a restraining wall and a restriction recess, is referred to as a movement restriction portion. It is desirable that the movement restricting portions are provided as the first movement restricting portion and the second movement restricting portion in the first portions 3 _i , 4 _i and the second portions 3 _ii , 4 _ii , respectively.

  In the load detector 100 of the first embodiment, 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 200 according to the second embodiment, a first connection portion that protrudes rearward from the first base portion 11 (on the fixed end 21s1 side of the first beam-type load cell) and a rearward portion from the second base portion 12 (second beam shape). A second connecting portion projecting to the fixed end 22s1 side of the load cell is pivotally connected at the center in the width direction, and the first and second beam type load cells 21 and 22 are rotated around the connecting point. It is good also as a structure which makes it change and the dimension of the circumferential direction of the mounting part 4 is changed. In this case, the slit s of the mounting portion 4 has a shape extending in the circumferential direction around the connection point between the first connection portion and the second connection portion.

  In the load detectors 100 and 200 of the first and second embodiments, one of the strain gauges 21g and 22g of the first and second beam-type load cells 21 and 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. Even in this case, the load detectors 100 and 200 can perform load detection.

  For example, in the case where the structures of the strain generating bodies 21s and 22s are the same and the spring constants thereof are the same, when the caster is placed at the midpoint between the connection center C1 and the connection center C2, the strain generation body 21s. , 22s have the same amount of deflection. Therefore, the load of the subject can be detected by doubling the detection value of one of the first and second beam type load cells 21 and 22 functioning as a load cell. When the load detectors 100 and 200 are load detectors that detect not only the absolute value of the subject's load but only the change in the subject's load, the load detectors 100 and 200 are arranged on the caster placement plates 31 and 41. The mounting position at is not particularly limited.

<Third Embodiment>
A load detection system 1000 according to the third embodiment will be described with reference to FIG.

  The load detection system 1000 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 1000, the casters CT attached to the four legs of the bed BD are placed on the placement portions 3 of the four load detectors 100, respectively. 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 value 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. .

  Since the load detection system 1000 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 the load detection system 1000 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. Further, instead of or in addition to the load detector 100, the load detector 200 of the second embodiment and the load detector of each modification may be used.

  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. .

  Since the load detector of the present invention is highly versatile and can be suitably used for various beds, it can contribute to the spread of state management based on load detection in hospitals, care facilities, and the like.

DESCRIPTION OF SYMBOLS 11 1st base, 12 2nd base, 21 1st beam type load cell, 22 2nd beam type load cell, 3, 4, 5 mounting part, 31, 41 mounting plate, 33,43 slope, 100,200 Load detection vessel

Claims (10)

A first beam-shaped strain body having a free end by being cantilevered on a first support;
A second beam-shaped straining body disposed opposite to the first beam-shaped straining body and having a free end by being cantilevered on a second support;
A mounting unit on which a subject is mounted, the first connecting unit connected to the first beam-shaped strain body and the second connecting unit connected to the second beam-shaped strain body. And at least one of the mounting portion provided between the first beam-shaped strain generator and the second beam-shaped strain body, and the first beam-shaped strain body and the second beam-shaped strain body. A load detector comprising a strain gauge attached to the
In the direction in which the first beam-shaped strain body extends, the free end of the second beam-shaped strain body is located on the opposite side of the free end of the first beam-shaped strain body. ,
The first connecting part of the mounting part is connected to the first beam-shaped straining body on the free end side of the first beam-shaped straining body, and the second connecting part of the mounting part is a second connecting part. The beam-type strain body is connected to the free end side of the second beam-shape strain body,
The placement unit has a first connection part and a first placement part and a second connection part on which at least a part of the subject is placed, and at least another part of the subject is placed A second placement portion to be placed;
The first mounting portion and the second mounting portion are load detectors that are connected so as to be relatively movable in a direction in which the first beam-shaped strained body and the second beam-shaped strained body face each other.   The first placement unit includes a first placement plate on which at least a part of the subject is placed, and a first slope that guides the at least part to the first placement plate. 2. The unit according to claim 1, further comprising: a second placement plate on which at least another part of the subject is placed; and a second slope that guides at least another part of the subject to the second placement plate. Load detector.   At least one of the first slope and the second slope is centered on a predetermined peristaltic axis, the first position where the tip contacts the installation surface on which the load detector is installed, and the tip is separated from the installation surface The load detector according to claim 2, wherein the load detector can swing between the second position and the second position.   The said mounting part further contains the lever extended on the opposite side to the said front-end | tip part with respect to the said peristaltic axis from at least one of the said 1st slope and the 2nd slope which can be swung. Load detector. A first beam-shaped strain body having a free end by being cantilevered on a first support;
A second beam-shaped strain body extending at an angle with respect to the first beam-shaped strain body and having a free end by being cantilevered on a second support base;
A mounting unit on which a subject is mounted, the first connecting unit connected to the first beam-shaped strain body and the second connecting unit connected to the second beam-shaped strain body. A placing portion provided between the first beam-shaped strain body and the second beam-shaped strain body,
A load detector comprising a strain gauge attached to at least one of the first beam-shaped strain body and the second beam-shaped strain body,
In the direction of the bisector of the angle defined between the extending direction of the first beam-shaped strained body and the extending direction of the second beam-shaped strained body, the first beam-shaped strained body The free end of the body is on the free end side of the second beam-shaped strain body, and the fixed end of the first beam-shaped strain body is on the fixed end side of the second beam-shaped strain body,
The distance between the free end of the first beam-type strainer and the free end of the second beam-type strainer is such that the fixed end of the first beam-type strainer and the second beam shape Greater than the distance between the fixed end of the strain body,
The first connecting portion of the first mounting portion is connected to the first beam-shaped strain generating body on the free end side of the first beam-shaped strain generating body, and the second connecting portion of the second mounting portion is the first connecting portion. Connected to the free end side of the second beam-shaped strain body and the second beam-shaped strain body,
The placement unit has a first connection part and a first placement part and a second connection part on which at least a part of the subject is placed, and at least another part of the subject is placed A second placement portion to be placed;
The first mounting portion and the second mounting portion are formed with the angle defined between the extending direction of the first beam-shaped strained body and the extending direction of the second beam-shaped strained body. A load detector connected so as to be relatively movable in the direction in which the size changes.   The first placement unit includes a first placement plate on which at least a part of the subject is placed, and a first slope that guides the at least part to the first placement plate. The unit according to claim 5, further comprising: a second placement plate on which at least another part of the subject is placed; and a second slope that guides the other at least part to the second placement plate. Load detector.   The first mounting portion has a first side wall that is adjacent to the first beam-shaped strain body and extends along the first beam-shaped strain body, and the second placement portion has a second beam shape. The load detector according to any one of claims 1 to 6, further comprising a second side wall adjacent to the strain body and extending along the second beam-shaped strain body.   The load detector according to any one of claims 1 to 7, wherein the strain gauge is attached to both the first beam-shaped strain body and the second beam-shaped strain body.   The first placement part is provided with a first movement restriction part that restricts movement of at least a part of the subject, and the second placement part restricts movement of at least another part of the subject. The load detector as described in any one of Claims 1-8 in which the 2nd movement control part is provided. 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 7 disposed 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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