JP6453396B2 - Load detector and load detection system - Google Patents

Description

  The present invention relates to a load detector including a slope 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. Although load detection can be performed by arranging load detectors at various positions, as an example, Patent Document 1 discloses disposing a load detector under a support leg that supports a bed. .

JP-A-2005-300368

  Patent Document 1 describes that a heavy object such as a bed is placed on a measurement dish of a load scale, but it cannot be said that a heavy object can be easily placed on a measurement dish. It is desirable that the load detector, such as a support leg of the bed, can be easily arranged below the load detection target.

  An object of this invention is to provide the load detector which can mount a detection target object easily, and the load detection system containing this load detector.

According to the first aspect of the present invention,
A beam-type load cell that is cantilever-supported on a support table, and a main body unit that includes a mounting table connected to the beam-type load cell; and a slope that is connected to the main body unit and guides the subject to the mounting table.
A load detector is provided in which the end of the slope and the end of the mounting table face each other in a non-contact manner.

  The load detector according to the first aspect may further include an elastic sheet that is attached to a bottom surface of the main body portion and a bottom surface of the slope and connects the main body portion and the slope.

  The load detector according to the first aspect may further include a rigid sheet attached to the bottom surface of the main body portion and the bottom surface of the slope to connect the main body portion and the slope.

  In the load detector according to the first aspect, the main body and the slope may be connected so as to be relatively movable in a direction in which the end of the slope and the end of the mounting table face each other.

  In the load detector according to the first aspect, the mounting table may include a concave portion that restrains the subject placed on the mounting table.

  In the load detector according to the first aspect, the beam type load cell is opposed to the first beam type load cell having a free end by being cantilevered on the first support base, and the first beam type load cell. And a second beam-type load cell having a free end by being cantilevered on the second support table, wherein the table is further connected to the first beam-type load cell. The first beam-type load cell may be provided between the first beam-type load cell and the second beam-type load cell. In the direction in which the shaped load cell extends, the free end of the second beam shaped load cell may be located on the opposite side of the free end of the first beam shaped load cell. Department The first beam-type load cell is connected to the free end side of the first beam-type load cell, and the second connecting portion of the mounting table is connected to the second beam-type load cell and the second beam-type load cell on the free end side. May be.

  In the load detector according to the first aspect, the first beam-type load cell and the second beam-type load cell may be arranged in parallel.

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 disposed under the legs of the bed;
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 easily place an object to be detected.

FIG. 1 is a perspective view of a load detector according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the load detector according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram for explaining a state in which the guide portion and the plate portion of the mounting table are engaged in a non-contact manner. FIG. 4 is an enlarged plan view showing a state in which the guide portion and the plate portion of the mounting table are engaged with each other in a non-contact manner, FIG. 4 (a) shows an embodiment, and FIG. 4 (b) shows a modification. An aspect is shown. FIG. 5 is a vertical cross-sectional view at the center in the width direction of the load detector, and shows a state where a bed caster is placed on the placing table. FIG. 6 is an explanatory diagram for explaining the relationship between the mounting position of the mounting table on the load cell and the preferable mounting position of the subject on the mounting table. FIG. 7 is an explanatory diagram showing the mounting position of the subject on the mounting plate in the load detector using one beam-type load cell. FIG. 8 is an explanatory diagram showing distances in the longitudinal direction and the width direction between the position of the subject placed on the mounting table and the mounting position of the mounting table on the load cell. FIG. 9 is an explanatory view showing a modification of the non-contact engagement portion. FIG. 10 is a perspective view showing a modification of the connecting portion of the mounting table. FIG. 11 is a schematic diagram showing the configuration of the load detection system according to the second embodiment of the present invention.

<First Embodiment>
An embodiment of the present invention will be described with reference to FIGS.

  As illustrated in FIGS. 1 and 2, the load detector 100 according to the embodiment includes a main body 100M, a guide 100G that guides a subject to the main body 100M, and a seat 100S on which the main body 100M and the guide 100G are installed. Including.

  The main body 100M includes first and second bases 11 and 12, beam-shaped first and second load cells 21 and 22 connected to the first and second bases 11 and 12, respectively, and first and second load cells. The mounting table 3 is mainly supported between the first and second load cells 21 and 22 by 21 and 22.

  In the following description, the beam extending direction of the beam-shaped first and second load cells 21 and 22 is referred to as the longitudinal direction of the load detector 100, and the side where the guide portion 100G is located in the longitudinal direction is referred to as the front side. . Further, a direction orthogonal to the longitudinal direction in the plane of the sheet 100S is referred to as a width direction. The surface on which the load detector 100 is installed is called a floor surface.

  The first base portion 11 of the main body portion 100M is a member that cantilever-supports the first load cell 21, and a flat plate portion 11a having a rectangular shape that is substantially the same as the first load cell 21 and an upward direction from the rear end of the flat plate portion 11a. And a support base portion 11b protruding from the bottom.

  Two screw holes Th are formed in the top surface 11bt of the support base portion 11b. The first load cell 21 is fixed to the support base portion 11b via a screw T and a screw hole Th.

  The second base portion 12 has the same shape as the first base portion 11 and includes a flat plate portion 12a and a support base portion 12b. The second base 12 is spaced apart from the first base 11 by a predetermined distance and is disposed facing the first base 11 (in parallel in this example), but the support base 11b of the first base 11 is a flat plate portion. The support base 12b of the second base 12 is provided in front of the flat plate portion 12a, whereas it is provided in the rear of 11a. That is, the position where the support base 11b is connected to the flat plate portion 11a of the first base 11 and the position where the support base 12b is connected to the flat plate portion 12a of the second base 12 are opposite to each other in the longitudinal direction. The second load cell 22 is fixed to the support base portion 12b through a screw T and a screw hole Th formed in the top surface 12bt of the support base portion 12b.

  The first load cell 21 is a beam-type load cell having a prismatic strain generating body 21s having a through hole h and a strain gauge 21g attached to the strain generating body 21s. The first load cell 21 detects the strain generated in the strain generating body 21s as a change in the resistance value of the strain gauge 21g, and thereby detects the load applied to the first load cell 21.

  The strain generating body 21s is a long prism formed of a metal such as aluminum or iron. A through hole h penetrating in the width direction is formed in the longitudinal center of the strain generating body 21s. The through-hole h has two circular holes hc having a circular cross-sectional shape and a rectangular hole hr having a substantially rectangular cross-sectional shape that connects the two circular holes hc in the longitudinal direction. A thin portion 21th whose thickness in the vertical direction is reduced due to the presence of the through hole h is defined in portions of the strain body 21s located above and below the through hole h.

  In the vicinity of the rear end 21ss of the strain body 21s, two screw holes Th penetrating in the vertical direction are formed. The rear end 21 ss of the strain body 21 is fixed to the support base portion 11 b of the first base portion 11 through the screw T and the screw hole Th. Thus, the strain generating body 21s is cantilevered by the first base 11 (support base 11b) with the rear end 21ss as a fixed end and the front end 21sf as a free end.

  Two screw holes Th penetrating in the vertical direction are also formed near the front end 21sf of the strain body 21s. The mounting table 3 is fixed to the lower surface 21 sd near the front end 21 sf of the strain body 21 s via a screw T and a screw hole Th. That is, the strain body 21s (first load cell 21) supports the mounting table 3 so as to be movable in the vertical direction in the vicinity of the front end 21sf which is a free end.

  Two strain gauges 21g are attached to the thin portion 21th of the strain body 21s. More specifically, one strain gauge 21g is attached to each of the upper surface 21st and the lower surface 21sd of the strain-generating body 21s at approximately the center in the longitudinal direction of the strain-generating body 21s. The strain gauge 21g is connected to an external control unit via a lead wire (not shown).

  The second load cell 22 has the same structure as the first load cell 21, and has a prismatic strain body 22s in which a through hole h penetrating in the width direction is formed at the center, and a thin portion 22th of the strain body 22s. And two strain gauges 22g attached to the. The second load cell 22 is spaced apart from the first load cell 21 by a predetermined distance, and is disposed opposite to the first load cell 21 (in this example, in parallel).

  Two screw holes Th penetrating in the vertical direction are formed in the vicinity of the front end 22ss of the strain body 22s. The front end 22ss of the strain body 22 is fixed to the support base portion 12b of the second base portion 12 via the screw T and the screw hole Th. As a result, the strain body 22s is cantilevered by the second base portion 12 (support base portion 12b) with the front end 22ss as a fixed end and the rear end 22sf as a free end.

  Two screw holes Th penetrating in the vertical direction are also formed near the rear end 22sf of the strain body 22s. The mounting table 3 is fixed to the lower surface 22sd in the vicinity of the rear end 22sf of the strain body 22s via a screw T and a screw hole Th. That is, the strain body 22s (second load cell 22) supports the mounting table 3 so as to be movable in the vertical direction in the vicinity of the rear end 22sf which is a free end. Looking at the positional relationship with the strain generating body 21s, the front end (fixed end) 22ss of the strain generating body 22s is at the same position as the front end (free end) 21sf of the strain generating body 21s in the longitudinal direction. The rear end (free end) 22sf is at the same position as the rear end (fixed end) 21ss of the strain body 21s in the longitudinal direction.

  That is, the strain-generating body 21s and the strain-generating body 22s extend in the same direction while facing each other, but the directions of the free ends with respect to their fixed ends are opposite to each other. Further, the support base portion 11b that supports the strain generating body 21s and the rear end (free end) 22sf of the strain generating body 22s are substantially at the same position in the longitudinal direction, and the support base portion 12b that supports the strain generating body 22s and the base The front end (free end) 21sf of the distorted body 21s is substantially at the same position in the longitudinal direction.

  The mounting table 3 is a weighing pan for mounting a subject when a load is detected using the load detector 100. The mounting table 3 includes a plate part P on which the subject is placed, a wall part W surrounding the plate part P in three directions, and a first connection part C1 and a second connection part C2 provided on the wall part W. Prepare.

  The plate portion P has a rectangular shape with the long side direction as the long side direction. In the center of the upper surface of the plate portion P, a concave portion R having a rectangular shape in plan view for restraining the subject as a rolling element is provided. As will be described later, the recess R is provided at a position where the subject is restrained on a line segment L connecting the mounting positions A1 and A2 (FIG. 6) to the first and second load cells 21 and 22 of the mounting table 3. ing.

  As shown in FIG. 3, the front end Pf of the plate portion P is provided with a plurality of recesses r arranged in the width direction. Details of the recess r will be described later. 1 and 2, the illustration of the recess r is omitted, and the illustration of the wall portion W is omitted in FIG. 3.

  The wall portion W is provided orthogonal to the plate portion P. The first long wall portion WL1, the second long wall portion WL2 extending along a pair of long sides of the plate portion P, and the rear of the plate portion P, respectively. A short wall portion WS extending along the end and connecting the rear end of the first long wall portion WL1 and the rear end of the second long wall portion WL2 is included.

  The first long wall portion WL1 and the second long wall portion WL2 protrude forward beyond the plate portion P. Hereinafter, the protruding portions of the first and second long wall portions WL1 and WL2 are referred to as first and second protruding portions WL1p and WL2p, respectively. The mutually opposing inner surfaces of the first protrusion WL1p and the second protrusion WL2p are configured as tapered surfaces so that the distance between the inner surfaces increases as the distance from the plate portion P increases in the longitudinal direction.

  On the outer surface of the first protrusion WL1p, a first connecting portion C1 having a plate shape parallel to the plate portion P is provided. The first connecting portion C1 is substantially square in plan view, and two screw holes Th are formed in a substantially central portion. The first connecting portion C1 is fixed to the lower surface 21sd of the strain body 21s in the vicinity of the front end 21sf (free end) of the strain body 21s of the first load cell 21 via the screw T and the screw hole Th (see FIG. 1, FIG. 2).

  On the outer surface of the short wall portion WS facing the side opposite to the side where the plate portion P is located, a second connecting portion C2 having a plate shape parallel to the plate portion P is provided. The second connecting portion C2 has a rectangular shape whose longitudinal direction is the width direction, and two screw holes Th are formed in the protruding portion protruding beyond the second long wall portion WL2. The second connecting portion C2 is fixed to the lower surface 22sd of the strain generating body 22s in the vicinity of the rear end 22sf (free end) of the strain generating body 22s of the second load cell 22 via the screw T and the screw hole Th (FIG. 1). , FIG. 2). As shown in FIG. 6, the screw hole Th of the first connecting part C1 and the screw hole of the second connecting part C2 are arranged so as to sandwich the plate part P in the diagonal direction.

  The guide portion 100G is a wedge-shaped (or triangular prism-shaped) member, and its upper surface is an inclined surface (slope) S that guides rolling elements such as casters CT (FIG. 5) from the floor surface to the mounting table 3. . A plurality of convex portions p arranged in the width direction are provided on the upper end St of the inclined surface S (FIG. 3). Details of the convex portion p will be described later. In FIG. 1 and FIG. 2, the protrusion p is not shown.

  The upper end St of the inclined surface S of the guide portion 100G is positioned so as to face the front end Pf of the plate portion P, and the first and second protrusions WL1p and WL2p extend on both sides in the width direction of the inclined surface S. ing. Therefore, when the subject is guided to the plate portion P by the inclined surface S, the subject is also guided in the width direction by the tapered surfaces inside the first and second protrusions WL1p and WL2p, and ascends the inclined surface S. As a result, it is led to the center in the width direction.

  The sheet 100S is a rectangular elastic sheet that shields vibrations from the floor surface and prevents the main body portion 100M and the guide portion 100G from sliding against the floor surface, and the bottom surfaces of the first and second base portions 11 and 12 and the guides. Affixed to the bottom surface of the portion 100G. Therefore, the main body portion 100M and the guide portion 100G are connected via the sheet 100S. The sheet 100S can be formed of synthetic rubber such as urethane rubber or silicone rubber, for example.

  Here, FIG. 3 and FIG. 4 are shown with respect to the facing portion between the plate portion P of the mounting table 3 having a plurality of concave portions r at the front end Pf and the inclined surface S of the guide portion 100G having the plurality of convex portions p at the upper end St. The description will be given with reference.

  As shown in FIG. 3, the plurality of convex portions p of the guide portion 100G project horizontally from the upper end St of the inclined surface S toward the rear. Each of the convex portions p has a shape in which the front end side (rear end side) short side of the rectangle whose long side is the long side direction is a semicircle in plan view, and the thickness (vertical dimension) is the plate portion P It is approximately equal to the thickness. Hereinafter, the end surface on the upper end St side of the inclined surface S including the side surface of the convex portion p is referred to as a slope end surface Se. The slope end surface Se is a vertical surface extending in a zigzag shape while reciprocating in the longitudinal direction.

  The plurality of concave portions r of the plate portion P are recessed from the front end Pf toward the rear. Each concave part r has a shape similar to the convex part p in plan view, and its dimension is slightly larger than the dimension of the convex part p. Hereinafter, the end surface on the front end Pf side of the plate portion P including the surface defining the recess r is referred to as a plate end surface Pe. Similar to the slope end surface Se, the plate end surface Pe is a vertical surface extending in a zigzag manner while reciprocating in the longitudinal direction.

  In a state where the main body portion 100M and the guide portion 100G are connected by the sheet 100S, the slope end surface Se and the plate end surface Pe are in contact with each other in a state where the plurality of convex portions p are respectively located inside the plurality of concave portions r. They face each other (FIG. 4 (a)). That is, the sheet 100S positions the main body portion 100M and the guide portion 100G so as to maintain a non-contact state as shown in FIG. The upper surface of the convex part p is flush with the upper surface of the plate part P. As shown in FIG. 4A, a region where the slope end surface Se extending in the longitudinal direction and the plate end surface Pe extending in the longitudinal direction are opposed to each other in the width direction, in other words, the projection p in the longitudinal direction is the plate portion P. The overlapping region is called a non-contact engagement region En. In the non-contact engagement region En, a part of the end portion of the plate portion P of the mounting table 3 enters a part of the end portion of the inclined surface S of the guide portion 100G in a non-contact manner.

  As described above, the inclined surface and the mounting table are referred to as “a portion in which the upper end of the inclined surface and one end of the mounting table overlap in the longitudinal direction without contacting each other” in the present specification. The state realized by the non-contact engagement part is called a “non-contact engagement” state. In this definition, the upper end of the inclined surface includes a portion provided integrally with the inclined surface at the upper end of the inclined surface, and one end of the mounting table includes a portion provided integrally with the mounting table at one end of the mounting table. Other examples of the non-contact engagement portion will be described later.

  Next, regarding the method of using the load detector 100, the subject is a subject on the bed, and a moving caster CT attached to the lower end of the bed leg BL (FIG. 5) is placed on the mounting table 3. The case where it is placed will be described as an example. In this case, the caster CT is also a part of the subject.

  When performing load detection using the load detector 100, first, the load detector 100 is installed at four locations on the floor corresponding to the leg BL, and then the caster CT is mounted on the plate portion P of the mounting table 3. Placed on. The caster CT is placed by guiding the caster CT on the floor surface onto the inclined surface S of the guide portion 100G from the floor surface and rolling it obliquely upward on the inclined surface S, and then the non-contact engagement region En. It moves by moving on the plate part P via.

  Here, when the caster CT is on the inclined surface S, all of the load of the caster CT is applied to the guide part 100G, and when the caster CT is on the plate part P, all of the load is applied to the main body part 100M. On the other hand, when the caster CT is in the non-contact engagement region En, the caster CT is simultaneously supported by the convex portion p and the plate portion P provided in the guide portion 100G, and therefore the load of the caster CT is the guide portion. 100G and the main body 100M are distributed and added. Therefore, by moving the caster CT to the plate portion P via the non-contact engagement region En, it is possible to prevent abrupt addition of the full load of the caster CT to the main body portion 100M.

  Further, in the present embodiment, in the non-contact engagement region En, the slope end surface Se and the plate end surface Pe are configured to face each other in a zigzag shape, and the facing portion between the slope end surface Se and the plate end surface Pe is in the width direction. The length extending in a straight line is smaller than the width of the caster CT. Therefore, unlike the aspect in which a linear gap across the width direction is formed in the facing portion between the inclined surface and the mounting table, the caster CT moving from the inclined surface S to the plate portion P falls into the gap, and the subject There is no impact.

  The caster CT that has moved onto the plate portion P moves rearward on the plate portion P, fits into the recess R, and stops. Thereby, the placement of the caster CT on the plate portion P is completed. The caster CT is held in a state in which movement is restricted by being restrained by the recess R.

  The casters attached to the other legs of the bed are also placed on the other load detectors 100 in the same manner.

  The load of the subject on the bed is applied to the strain body 21 s of the first load cell 21 and the strain body 22 s of the second load cell 22 that support the mounting table 3 via the bed leg BL, the caster CT, and the mounting table 3. Communicated. At the time of load detection, the mounting table 3 moves downward under the load of the subject. At this time as well, the slope end surface Se of the upper end St of the inclined surface S and the plate portion P of the mounting table 3 in the non-contact engagement region En. The plate end surface Pe does not come into contact with each other, and the non-contact state between the inclined surface S and the plate portion P is maintained.

  Strain is generated in each of the strain generating body 21s and the strain generating body 22s to which the load is transmitted, and the strain gauges 21g and 22g detect the strain as a change in resistance value. The detected change in resistance value is output to the outside or a control unit (not shown) provided in the first base 11 or the second base 12 via a lead wire (not shown). By performing arithmetic processing in the control unit, the load of the subject can be obtained.

  Here, in the load detector 100 of the present embodiment, the reason why the mounting table 3 is supported at two points using the first load cell 21 and the second load cell 22 will be described.

  In the load detector 100 of the present embodiment, as shown in FIG. 6, the mounting table 3 is supported in the vicinity of the front end 21 sf of the strain body 21 s of the first load cell 21 via the first connecting portion C <b> 1 so as to be vertically movable. The second load cell 22 is supported in the vicinity of the rear end 22sf of the second load cell 22 through the second connecting portion C2 so as to be vertically movable.

  Here, if the center point of attachment of the first connecting portion C1 to the strain generating body 21s is the attachment center A1, and the center point of attachment of the second connecting portion C2 to the strain generating body 22s is the attachment center A2, the mounting table 3 is most difficult to bend on the line segment L connecting the attachment center A1 and the attachment center A2 with the shortest distance. Therefore, by placing the bed caster CT on the line segment L, it is possible to detect the load of the subject on the bed while suppressing the influence of the deflection of the mounting table 3.

  As described above, the concave portion R is formed in the plate portion P of the mounting table 3 so as to restrain the subject on the line segment L. Therefore, by simply disposing the caster CT in the recess R, the caster CT can be stably disposed on or near the line segment L, and the load of the subject can be detected stably and accurately.

  Here, the reason why the load detector of the present invention can detect the load stably and accurately as compared with the load detector using the conventional beam type load cell is shown in FIG. The description will be given with reference. As shown in FIG. 7, in the load detector 900 in which the mounting plate PT is attached to the end of the beam-type load cell LC, the displacement error is caused by the fact that the mounting position pn 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 A0 with the PT, the placement position pn increases as the distance from the connection position A0 increases. This is because 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 as the mounting position pn is separated from the connection position A0 in the longitudinal direction of the beam type load cell LC. 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 pn is separated from the connection position A0 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. 8, the longitudinal direction between the mounting position PN and the mounting center A1 of the subject placed on the plate part P of the mounting table 3 is shown. distance _{x P1,} if the longitudinal distance between the placement position PN and the mounting center A2 and _{x P2,} the sum of _{x P1} and _{x P2} is constant at substantially the entire region on the plate portion P of the table 3 . Therefore, in the load detector 100 according to the present embodiment, even if the placement position PN moves in the front-rear direction, the displacement error due to the bending moment generated in the first load cell 21 and the displacement error due to the bending moment generated in the second load cell 22. The sum of and is always substantially constant. Therefore, for example, the control unit (not shown) adds the detection values of the first load cell 21 and the second load cell 22 and subtracts a predetermined value as the deviation error, thereby affecting the influence of the deviation error due to the bending moment. It is possible to stably detect the load of the subject in a state in which is substantially removed.

Further, as shown in FIG. 8, the distance in the width direction between the mounting position PN and the mounting center A1 of the subject mounted on the plate part P of the mounting table 3 is y _P1 , and the mounting position PN and the mounting center A2. When the distance in the width direction and y _P2 with the sum of y _P1 and y _P2 is constant at substantially the entire region on the plate portion P of the table 3. Therefore, in the load detector 100 according to the present embodiment, even if the placement position PN moves in the width direction, the deviation error due to the torsional moment generated in the first load cell 21 and the deviation error due to the torsional moment generated in the second load cell 22. The sum of and is always substantially constant. Therefore, for example, by adding the detection results of the first load cell 21 and the second load cell 22 in the control unit (not shown) and subtracting a predetermined constant value as the displacement error, the displacement error due to the torsional moment is reduced. The load to be measured can be stably detected in a state where the influence is substantially removed.

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

  Since the load detector 100 of this embodiment has the guide part 100G which has the inclined surface S, the test subject which is rolling elements, such as caster CT, can be easily introduce | transduced on the mounting base 3. FIG. In addition, since the slope end surface Se of the guide portion 100G and the plate end surface Pe of the mounting table 3 face each other in a non-contact manner, and the guide portion 100G is not in contact with the mounting table 3, measurement due to interference of the guide portion 100G. There is no error.

  The load detector 100 of the present embodiment is easy to carry because the main body 100M and the guide 100G are integrally connected by the seat 100S.

  In the load detector 100 of the present embodiment, a plurality of convex portions p of the guide portion 100G and the plate portion P are non-overlapping regions in the longitudinal direction at the facing portion between the guide portion 100G and the plate portion P. A contact engagement area En is defined. Therefore, the total load of the subject moving from the inclined surface S onto the plate part P is prevented from being suddenly applied to the plate part P. This leads to a long life of the load detector 100. Further, since there is no linear gap between the inclined surface S and the plate portion P that exceeds the width of the caster CT, that is, a gap in which the caster CT can be fitted when passing, the caster CT is smoothly placed on the plate portion P. Can move.

  Since the load detector 100 of the present embodiment includes the seat 100S, measurement errors due to floor vibrations are suppressed. In addition, measurement errors that can be caused by slipping of the main body 100M with respect to the floor are also suppressed.

  In the load detector 100 of this embodiment, the mounting table 3 is supported at two points by the first load cell 21 and the second load cell 22 via the first connection part C1 and the second connection part C2. Therefore, by placing the subject on the line segment L connecting the two support points, the influence of the deflection of the mounting table 3 (particularly the plate portion P) can be suppressed and the load of the subject can be detected well. Moreover, since the recessed part R is provided in the plate part P, a test subject can be arrange | positioned on the line segment L easily.

  In the load detector 100 of the present embodiment, the total value of the deviation errors generated in the first and second load cells 21 and 22 due to the bending moment, and the first and second load cells 21 and 22 due to the torsional moment, The total value of the deviation errors generated in 22 is always substantially constant. Therefore, by adding the measurement value of the first load cell 21 and the measurement value of the second load cell 22 and subtracting the deviation error, the influence of the deviation error is substantially removed and accurate and stable load detection is performed. be able to.

<Modification>
In the load detector 100 of the above embodiment, the following modification can be used.

  The sheet 100S may be a rigid sheet formed of a rigid member such as metal or plastic instead of the elastic sheet described above. In this case, when the caster CT is mounted on the mounting table 3 of the load detector 100, a relative positional shift between the mounting table 3 and the inclined surface S is less likely to occur, so that the non-contact engagement state is further increased. It is preferable because it can be reliably maintained. In the present invention, the rigid sheet means a sheet having rigidity sufficient to lift up the guide part 100G without bending when only the main body part 100M is lifted, and the elastic sheet means the main body part 100M. When lifting only the guide member 100G, the guide member 100G is lifted integrally while elastically deforming and bending, and when the main body 100M is placed on the floor again, the sheet has an elasticity enough to return to the state before elastic deformation. Means.

  Instead of the sheet 100S, the guide portion 100G is fixedly connected to the side surface, the upper surface, or the like of the first base portion 11 or the second base portion 12 of the main body portion 100M by a connecting member such as a rod-like or plate-like member. The positioning of the plate P) and the guide portion 100G (inclined surface S) may be performed. In addition, the connection between the guide part 100G and the main body part 100M can be performed by an arbitrary method of directly connecting the two parts or an arbitrary method of connecting the two through another member for connection. The connection between the guide portion 100G and the main body portion 100M is not limited to a mode in which both are fixedly connected, and “non-contact mooring” described later is one of the methods for connecting both. Further, in the load detector 100, the main body portion 100M and the guide portion 100G may not be integrally connected but can be separated.

  Another example of the non-contact engagement portion will be described with reference to FIG. The non-contact engagement portion shown in FIG. 4B is substantially the same as the non-contact engagement portion of the above embodiment, but the shapes of the convex portion p of the inclined surface S and the concave portion r of the plate portion P are the same as those described above. Unlike the convex part p and the concave part r, the shape is an isosceles triangle. Thus, even if the shape of the convex part p and the recessed part r is changed, a non-contact engagement part can be comprised similarly to the said embodiment. That is, the shape of the convex part p and the shape of the recessed part r are arbitrary as long as the convex part p can penetrate | invade in the recessed part r without contact, for example, round shape may be sufficient. Moreover, the shape of the convex part p and the shape of the recessed part r do not necessarily need to be similar, and as long as the convex part p can penetrate | invade in the recessed part r non-contactingly, it can be set as arbitrary different shapes. Further, a concave portion may be provided on the inclined surface S side, and a convex portion may be provided on the plate portion P side.

  In the non-contact engagement part, making the upper surface of the upper end of the inclined surface and the upper surface of one end of the mounting table flush with each other means that the subject moves smoothly and prevents sudden loading on the mounting table. Although it is preferable from a point, it is not restricted to this.

  Still another example of the non-contact engagement portion will be described with reference to FIG. The non-contact engaging portion shown in FIG. 9 includes a first key portion L1 having a substantially U shape in side view provided integrally with the plate portion P at the front end Pf of the plate portion P, and an inclined surface at the upper end St of the inclined surface S. S is comprised by the 2nd key part L2 of the side view substantially L-shape provided integrally. Also in this configuration, the inclined surface S and the mounting table 3 are not in contact with each other, and the second key portion L2 provided integrally with the upper end St of the inclined surface S and the front end Pf of the plate portion P of the mounting table 3 are provided. Are arranged so as to overlap with the first key portion L1 provided integrally therewith in the longitudinal direction. More specifically, the first key portion L1 enters the second key portion L2 in the vertical direction. Since the first key portion L1 is below the second key portion L2, the first key portion L1 and the second key portion L2 are also located when the subject is placed on the plate portion P and the plate portion P moves downward at the time of load detection. There is no contact with the key L2. When carrying the load detector 100, the inclined surface S and the mounting table 3 can be moved together by lifting the main body 100M so that the first key L1 is caught by the second key L2. . According to the load detector having the non-contact engagement portion of this aspect, the subject can be easily placed on the placement table using the inclined surface S.

  The load detector 100 of the above embodiment may not have a non-contact engagement portion. For example, the upper end St of the inclined surface S may not have the convex part p, and the front end Pf of the plate part P may not have the concave part r. In this case, in the facing portion between the inclined surface S and the plate portion P, a flat slope end surface Se extending linearly in the width direction and a flat plate end surface Pe extending linearly in the width direction are arranged in the width direction. It has a gap extending in a straight line and faces each other without contact.

  The load detector 100 according to the present embodiment may include a “non-contact mooring portion” instead of the non-contact engagement portion. In the present specification, the “non-contact mooring portion” means “a portion where the inclined surface S and the main body portion 100M are connected to each other without being in contact with each other and being separated to a predetermined distance in the longitudinal direction”. It shall be. A state realized by the non-contact mooring portion is referred to as a non-contact mooring state.

  An example of the non-contact mooring part is a connecting part of the inclined surface S and the main body part 100M by a string, a chain or the like. A string, a chain, or the like may be connected to any of the first and second base parts 11 and 12, the first and second load cells 21 and 22, and the mounting table 3 of the main body part 100 </ b> M. Another example of the non-contact mooring part is a connecting part in which the inclined surface S and a part of the main body part 100M are connected by a rod that can be expanded and contracted in the longitudinal direction. A rod etc. can be connected with the 1st and 2nd base parts 11 and 12 of main part 100M, for example.

  In the load detector 100 of the present embodiment, the plate portion P may extend to the front ends of the first and second protrusions WL1p and WL2p. In this case, the guide portion 100G is disposed in front of the front ends 21sf and 22ss of the first and second load cells 21 and 22. In this case, the guide portion 100G may have tapered guide walls on both sides of the inclined surface S in the width direction for guiding the subject toward the center portion in the width direction.

  The 1st connection part C1 and the 2nd connection part C2 which the mounting base 3 of the said embodiment has can be comprised as shown in FIG. That is, the first connecting part C1 includes a vertical part C1v extending upward in parallel with the first long wall part WL1, and a horizontal part C1h extending in the horizontal direction perpendicular to the vertical part C1v from the upper end part of the vertical part C1v. The second connecting portion C2 includes a rectangular first horizontal portion C2h1 extending in a horizontal direction from the short wall portion WS and a vertical portion extending upward from the short side of the first horizontal portion C2h1 on the second long wall portion WL2 side. C2v and a second horizontal portion C2h2 extending in the horizontal direction perpendicular to the vertical portion C2v from the upper end portion of the vertical portion C2v. The first connecting portion C1 is coupled to the upper surface 21st of the strain generating body 21s near the front end 21sf of the strain generating body 21s of the first load cell 21, and the second connecting portion C2 is connected to the strain generating body of the second load cell 22. In the vicinity of the rear end 22sf of 22s, it is coupled to the upper surface 22st of the strain generating body 22s.

  In the main body 100M of the above-described embodiment, the following modification can also be used.

  In the main body portion 100M of the above embodiment, the flat plate portion 11a of the first base portion 11 and the flat plate portion 12a of the second base portion 12 may be omitted and the support base portions 11b and 12b may be attached to the sheet 100S. Further, the first base portion 11 and the second base portion 12 may be integrated.

  In the main body 100M of the above embodiment, the connecting method of the support bases 11b and 12b and the first and second load cells 21 and 22 is arbitrary, for example, connected to the rear end surfaces of the first and second load cells 21 and 22 Also good. The connection between the first and second load cells 21 and 22 and the mounting table 3 is the same.

  In the main body 100M of the above embodiment, the first load cell 21 and the second load cell 22 face each other in parallel, but the first load cell 21 and the second load cell 22 have an angle smaller than about 5 °. You may face each other. The number of strain gauges attached to each load cell is arbitrary.

  In the load detector 100 of the above embodiment, the recess R may not be formed in the plate portion P of the mounting table 3. Further, the mounting table 3 may not have the wall portion W.

  In the main body 100M of the above embodiment, the first connecting part C1 of the mounting table 3 is attached in the vicinity of the front end 21sf of the strain body 21s of the first load cell 21, but the first connecting part C1 of the mounting table 3 is What is necessary is just to be attached to the front side (free end side) from the longitudinal direction center of the strain body 21s. Moreover, the 1st connection part C1 of the mounting board 3 can also be attached to the arbitrary positions of the free end side rather than the thin part 21th of the strain body 21s. The same applies to the attachment of the second connecting portion C2 to the strain generating body 22s of the second load cell 22.

  In the above embodiment, the first and second connecting portions C1 and C2 of the mounting table 3 are formed at both ends in the longitudinal direction of the mounting table 3, but the present invention is not limited thereto. The 1st, 2nd connection part C1, C2 should just be provided in the longitudinal direction of the mounting base 3, respectively on the opposite side on both sides of the longitudinal direction center.

  The main body 100M of the above embodiment may be a single load cell type load detector 900 as shown in FIG. 6 or a load scale having three load cell sensors as shown in Patent Document 1.

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 mounted on the mounting table 3 of the four load detectors 100 (FIG. 11). 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 adds the output from the first load cell 21 and the output from the second load cell 22 of each load detector 100 to obtain a predetermined value corresponding to the deviation error. A load calculation process to be subtracted and a load summing process to add the load detected by each load detector 100 are performed. 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 bed BD can be mounted on the four mounting tables 3 simply by moving the bed BD in one direction, rolling each of the four casters CT of the bed BD and ascending on the inclined surface S. There is an effect that the BD can be arranged on the load detector 100 without any trouble.

  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, it is possible to easily arrange a subject on a mounting table and perform good load detection with suppressed errors. Therefore, when this is used in a hospital, a nursing facility, etc., the load of the subject on the bed can be detected easily and accurately, which can contribute to the improvement of the quality of medical care and nursing care.

11 First base part 12 Second base part 21 First load cell 22 Second load cell 3 Mounting table 100 Load detector 100G Guide part 100M Body part 100S Seat 500 Load detection system BD Bed CT Caster P Plate part S Inclined surface

Claims (8)

A beam-type load cell that is cantilever-supported on a support table, and a main body unit that includes a mounting table connected to the beam-type load cell; and a slope that is connected to the main body unit and guides the subject to the mounting table.
The end of the slope and the end of the mounting table face each other in a non-contact manner ,
A load detector in which the main body and the slope are connected so as to be relatively movable in a direction in which an end of the slope and an end of the mounting table face each other. The beam-type load cell is cantilevered on the first support base, and is disposed opposite to the first beam-type load cell having a free end, and on the second support base. A second beam load cell having a free end by being cantilevered;
  The mounting table 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. It is provided between the beam type load cells,
  In the direction in which the first beam-type load cell extends, the free end of the second beam-type load cell is located opposite to the free end of the first beam-type load cell;
  The first connection part of the mounting table is connected to the first beam-type load cell on the free end side of the first beam-type load cell, and the second connection part of the mounting table is connected to the second beam-type load cell and the second beam-type load cell. The load detector according to claim 1, which is connected on the free end side of the beam-type load cell. A main body including a beam-type load cell cantilevered on a support base and a mounting base connected to the beam-type load cell;
  A slope connected to the main body and for guiding the subject to the table,
  The end of the slope and the end of the mounting table face each other in a non-contact manner,
  The beam-type load cell is cantilevered on the first support base, and is disposed opposite to the first beam-type load cell having a free end, and on the second support base. A second beam load cell having a free end by being cantilevered;
  The mounting table 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. It is provided between the beam type load cells,
  In the direction in which the first beam-type load cell extends, the free end of the second beam-type load cell is located opposite to the free end of the first beam-type load cell;
  The first connection part of the mounting table is connected to the first beam-type load cell on the free end side of the first beam-type load cell, and the second connection part of the mounting table is connected to the second beam-type load cell and the second beam-type load cell. A load detector connected on the free end side of the beam-type load cell. The load detector according to claim 3, further comprising an elastic sheet that is attached to a bottom surface of the main body portion and a bottom surface of the slope and connects the main body portion and the slope. The load detector according to claim 3, further comprising a rigid sheet attached to a bottom surface of the main body portion and a bottom surface of the slope to connect the main body portion and the slope. The load detector according to any one of claims 2 to 5, wherein the first beam-type load cell and the second beam-type load cell are arranged in parallel. The load detector according to any one of claims 1 to 6, wherein the mounting table includes a concave portion that restrains the subject mounted on the mounting table. A load detection system for detecting the load of a subject on a bed,
A plurality of load detectors according to any one of the preceding claims, disposed under the legs of the bed;
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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