WO2017195663A1

WO2017195663A1 - Load detection unit, bed, and load detection system

Info

Publication number: WO2017195663A1
Application number: PCT/JP2017/016963
Authority: WO
Inventors: 徳仁飯田; 順八町
Original assignee: ミネベアミツミ株式会社
Priority date: 2016-05-09
Filing date: 2017-04-28
Publication date: 2017-11-16
Also published as: JP6189997B1; JP2017203642A

Abstract

A load detection unit (100) is provided with a load detection part (100M) including a loading stand (PL) for loading a subject, an attachment part (100A) for attaching the load detection part to a portion of the subject, and a link mechanism (100C) for connecting the load detection part and the attachment part. The link mechanism moves the load detection part between a detection position in which the load detection part is installed on a floor surface and the subject is loaded on the loading stand and a separation position in which the load detection part is separated from the floor surface in a state in which the attachment part is attached to the subject.

Description

Load detection unit, bed and load detection system

The present invention relates to a load detection unit used by being attached to a subject, a bed including the load detection unit, and a load detection system including the load detection unit.

There is known detection of bed presence by detecting a load applied to a bed in a hospital or a nursing facility and determining whether a patient or a resident is present on the bed. The load can be detected by arranging the load detectors at various positions. As an example, Patent Document 1 discloses a load detector arranged under a support leg that supports the bed.

Japanese Patent Laying-Open No. 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.

It is an object of the present invention to provide a load detection unit that can easily place an object to be detected, a bed including the load detection unit, and a load detection system including the load detection unit.

According to the first aspect of the present invention,
A load detector including a mounting table for mounting the subject; and
An attachment part for attaching the load detection part to a part of the subject,
A link mechanism for connecting the load detection unit and the mounting unit;
The link mechanism is configured such that the load detection unit is installed on the floor and the subject is placed on the mounting table in a state where the attachment unit is attached to the subject. There is provided a load detection unit that moves between a detection position and a separation position where the load detection unit is separated from the floor surface.

In the load detection unit according to the first aspect, the mounting table may have an inclined surface, and the subject may roll on the inclined surface and be mounted on the mounting table.

In the load detection unit according to the first aspect, at least one of the load detection unit, the attachment unit, and the link mechanism includes a movement restriction unit that restricts the load detection unit from moving beyond the detection position. It may be provided.

In the load detection unit according to the first aspect, the lower end of the mounting table may be separated from the floor surface at the detection position.

In the load detection unit according to the first aspect, the link mechanism is pivoted to the load detection unit and the attachment portion on both sides in a direction orthogonal to the moving direction in which the load detection portion and the attachment portion move relative to each other. It may be movably connected.

In the load detection unit according to the first aspect, a concave portion may be formed on the top surface of the mounting table, and the concave portion is located on the mounting table of the load detection unit at the detection position. You may position so that it may intrude in the said recessed part.

In the load detection unit according to the first aspect, the load detection unit may include a beam-type load cell that is cantilevered on a support table, and the mounting table may be connected to the beam-type load cell.

In the load detection unit according to the first aspect, the beam-type load cell faces the first beam-type load cell, 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. One connection portion and a second connection portion connected to the second beam-type load cell, and may be provided between the first beam-type load cell and the second beam-type load cell,
In the direction in which the first beam load cell extends, the free end of the second beam load cell may be located on the opposite side of the free end of the first beam 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 beam-type load cell may be connected on the free end side.

In the load detection unit of 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,
Floor boards,
Legs supporting the floorboard;
A caster provided at the lower end of the leg,
A bed comprising the load detection unit of the first aspect attached to the leg part,
A bed in which the mounting direction of the load detection unit and the load detection unit move relative to each other corresponds to the traveling direction of the caster.

In the bed according to the second aspect, the caster may be rotatable around a vertical axis, and the load detection unit and the caster attached to the leg portion rotate integrally around the vertical axis. Also good.

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 detection units of the first aspect attached to the legs of the bed;
A load detection system is provided that includes a control unit that is connected to the plurality of load detection units and calculates the load of the subject based on the output of the load detection unit.

The load detection unit, bed, and load detection system of the present invention can easily place a detection object.

FIG. 1 is a perspective view of a load detection unit according to the first embodiment of the present invention. FIG. 2 shows an example of a bed to which a load detection unit is attached. FIG. 3 shows the load detection unit attached to the rotating column of the bed, and shows a state where the load detection unit is in the separated position. FIG. 4 shows the load detection unit attached to the rotating column of the bed, and shows a state where the load detection unit is in contact with the floor. FIG. 5 shows the load detection unit attached to the rotating column of the bed, and shows a state where the load detection unit is at the detection position. FIG. 6 shows the load detection unit attached to the rotating column of the bed, and shows a state where the inclined surface of the weighing pan of the load detection unit is in contact with the caster. FIG. 7 is a perspective view illustrating an example of a load detector included in the load detection unit. FIG. 8 is an exploded perspective view showing an example of a load detector included in the load detector. FIG. 9 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. 10 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. 11 is an explanatory diagram showing the distance 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. 12 is a perspective view showing a modification of the connecting portion of the mounting table. FIG. 13 shows a configuration of a load detection system according to the second embodiment of the present invention.

<First Embodiment>
With reference to FIGS. 1 to 6, in the load detection unit 100 according to the first embodiment of the present invention, when the subject is a bed BD provided with a caster CT on a rotating column rp as shown in FIG. The subject is a subject on the bed BD, but the bed BD is also considered as a part of the subject).

As shown in FIG. 1, the load detection unit 100 according to the first embodiment includes a load detection unit 100M including a weighing pan PL, an attachment unit 100A for attaching the load detection unit 100M to the bed BD, a load detection unit 100M, and an attachment unit 100A. And a link mechanism 100C for connecting the two to each other so as to be relatively movable.

In the following description, the direction in which the load detection unit 100M and the attachment unit 100A are arranged in FIG. 1 is referred to as the front-rear direction, and in this front-rear direction, the side where the attachment unit 100A is located is the front side. Called the back side. Moreover, the direction orthogonal to the front-back direction in the upper surface of the weighing pan PL is called a width direction. In the load detection unit 100 of the present embodiment, the attachment portion 100A is attached to the bed BD, and the attachment portion 100A and the load detection portion 100M are moved toward and away from each other in the front-rear direction, whereby the bed BD to the weighing pan PL is moved. The caster CT can be introduced and the caster CT can be detached from the weighing pan PL.

The load detection unit 100M includes a load cell (not shown) including a load cell (not shown) and a weighing pan PL connected to the load cell, and a storage unit HS for receiving the load detector in a state where the weighing pan PL is exposed. Including. In the front region of the weighing pan PL, an inclined surface PLS for guiding rolling elements such as casters onto the weighing pan PL is provided. On both side surfaces HSS of the housing portion HS, convex portions (movement restriction portions) for restricting movement of first and second rear arms 81 and 82 (that is, relative movement between the attachment portion 100A and the load detection portion 100M), which will be described later. ) P11 and p12 are provided.

As the load detector accommodated in the accommodating portion HS, various types of load detectors including various sensors such as one or a plurality of load cells, piezoelectric sensors, and displacement sensors can be used. Specific examples thereof will be described later.

The mounting portion 100A includes a receiving portion 61 that receives the rotating column rp of the bed BD as a subject, and a pair of beam portions 62 that extend from the receiving portion 61 to both sides in the width direction. The receiving part 61 is a plate member having a square shape in plan view, and has a through hole 61a at the center. When attaching the attachment portion 100A to the bed BD, the rotating column rp of the bed BD is inserted into the through hole 61a.

The link mechanism 100C includes a first link L1 and a second link L2 provided with the load detection unit 100M and the attachment unit 100A sandwiched in the width direction. The first link L1 includes a first front arm 71 and a first rear arm 81, and the second link L2 includes a second front arm 72 and a second rear arm 82.

The front end 81f of the rear end 71r and the first rear arm 81 of the first front arm 71 of the first link L1, is pivotally connected by a pivot pin pp1 to the central axis the axis X ₁ extending in the width direction cage is pivotable about the axis X _1. A connecting portion between the first front arm 71 and the first rear arm 81 is provided with a torsion spring S11 that biases the front end 71f of the first front arm 71 upward. The first front arm 71 urged by the torsion spring S <b> 11 can pivot until it abuts against the convex portion p <b> 2 provided at the front end 81 f of the first rear arm 81. The first front arm 71 is substantially straight with the first rear arm 81 in a state where the first front arm 71 is in contact with the convex portion p2.

Similarly, the rear end 72r of the second front arm 72 of the second link L2 and the front end 82f of the second rear arm 82, pivotably by a pivot pin pp1 to the central axis the axis X ₁ extending in the width direction are connected, it is pivotable about an axis X _1. A connecting portion between the second front arm 72 and the second rear arm 82 is provided with a torsion spring S12 that urges the front end 72f of the second front arm 72 upward. The second front arm 72 biased by the torsion spring S12 can pivot until it comes into contact with the convex portion p2 provided at the front end 82f of the second rear arm 82. The second front arm 72 is substantially straight with the second rear arm 82 in a state where the second front arm 72 is in contact with the convex portion p2.

Linkage 100C of the first front end of the front arm 71 71f, the front end 72f of the second front arm 72, the tip of the pair of beam portions 62 of the mounting portion 100A, respectively, and the central axis of the shaft _{X 2} extending in the width direction Pivotally connected by a pivot pin pp2. Attaching portion 100A and the first and the second

front arm

71, 72 is pivotable about the axis _{X 2.} Between the first and second

front arms

71 and 72 and the beam portion 62, torsion springs S21 and S22 for urging the

rear ends

71r and 72r of the first and second

front arms

71 and 72 upward, respectively. Is provided.

Rear end 81r of the first rear arm 81 of the link mechanism 100C, the rear end 82r of the second rear arm 82, respectively, pivot in the housing portion HS by a pivot pin pp3 around axis the axis _{X 3} extending in the width direction rotatably on are connected, it is pivotable about the axis X _3. Between the first and second

rear arms

81 and 82 and the housing portion HS, the front end HSf of the housing portion HS is urged upward (first and second rear arms 81 and 82), respectively. The torsion springs S31 and S32 are provided to urge the front ends 81f and 82f downward. The first and second

rear arms

81 and 82 urged by the torsion springs S31 and S32 can pivot to positions where they abut against the convex portion p11 of the housing portion HS. The first and second

rear arms

81 and 82 extend at a predetermined angle (about 15 ° as an example) with respect to the front-rear direction in a state where the first and second

rear arms

81 and 82 are in contact with the convex portion p11.

Next, a method of using the load detection unit 100 of this embodiment will be described.

A typical bed BD shown in FIG. 2 has a pair of beams bm extending in the longitudinal direction of the floor plate fb in the vicinity of both ends in the short direction of the floor plate fb below the floor plate fb, and at both ends of the beam bm. The caster CT is attached via a cylindrical rotary support rp. Each of the rotating struts rp can freely rotate around its central axis _Xrp , and the caster CT also rotates integrally with the rotating strut rp.

The load detection unit 100 is attached to the rotation column rp so that the load detection unit 100 rotates integrally with the rotation column rp and the caster CT in a state where the traveling direction of the caster CT coincides with the front-rear direction of the load detection unit 100. . Specifically, for example, the four rotation struts rp are once removed from the beam bm, and each is inserted into the through hole 61a of the mounting portion 100A and attached to the beam bm again. If necessary, a screw is passed through the side surface of the receiving portion 61 and tightened. Thus, by attaching the load detection unit 100 to the rotating column rp so as to rotate integrally with the rotating column rp and the caster CT, the caster CT rotating around the central axis _Xrp is oriented in any direction. The load detector 100M and the weighing pan PL are positioned in the traveling direction of the caster CT. Note that the receiving unit 61 may be divided into, for example, the front and rear, and the load detection unit 100 may be attached without removing the rotary support rp from the beam bm.

In a state in which the mounting portion 100A is mounted on the rotary column rp, the load detection unit 100 includes the first and second

front arms

71 and 72 and the first and second

rear arms

81 and 82 as shown in FIG. The load detection unit 100M extends in a straight line and is maintained at a separated position away from the floor surface F. At this time, the first and second

rear arms

81 and 82 are urged by the torsion springs S31 and S32 and are in contact with the convex portion p11, and the first and second

front arms

71 and 72 are torsion springs S11 and S12. And is in contact with the convex portion p2. In the load detection unit 100M and the link mechanism 100C (the first link L1 and the second link L2), the load detection unit 100M is stopped slightly below the mounting unit 100A due to the balance between the elastic force of the torsion springs S21 and S22 and gravity. Maintained in a state.

In the state shown in FIG. 3, since the load detection unit 100M is maintained at a separated position away from the floor surface F, the load detection unit 100 does not hinder the movement of the bed BD, and the operator rotates the caster CT. The bed BD can be moved freely by moving.

After moving the bed BD to the intended use position, the worker places the four casters CT of the bed BD on the weighing pan PL of the load detection unit 100M. This placement is performed as follows, for example.

After moving the bed BD to the intended use position, first, the caster CT is adjusted so that all the traveling directions thereof coincide with the longitudinal direction of the bed BD. This adjustment can be performed, for example, by moving the bed BD somewhat along the longitudinal direction.

Load detection unit 100M, respectively, because it is fixed to the rotating strut rp to rotate caster CT integrally around the central axis X _rp, when the traveling direction of the four casters CT are aligned in the longitudinal direction of the bed BD The four load detection units 100M are all arranged on one side in the longitudinal direction of the four casters CT (the head side or the leg side of the bed BD).

Next, the worker moves the load detection unit 100M downward and forward and contacts the floor F (FIG. 4). Thereby, the weighing pan PL of the load detection unit 100M is arranged in the vicinity of the caster CT on one side in the traveling direction of the caster CT. Thereafter, the operator pushes the bed BD toward the load detection unit 100M to roll the caster CT, and moves the caster CT onto the weighing pan PL via the inclined surface PLS (FIG. 5). When the load detection unit 100M is installed (grounded) on the floor F and the caster CT is placed on the weighing pan PL, the load detection unit 100M is at the detection position.

Here, since the weighing pan PL of the load detection unit 100M needs to be displaced up and down according to the load at the time of load detection, in the state where the load detection unit 100M is grounded to the floor F, the lower end of the inclined surface PLS (measurement) The lower end LE of the plate PL) is in a state of being separated from the floor surface F (FIGS. 4 and 5). When the caster CT moves on the inclined surface PLS, it is necessary to overcome the step between the floor surface F and the lower end LE. However, when the caster CT rides on the inclined surface PLS, the caster CT includes the torsion spring S11, Since the elastic force of S12, S21, S22, S31, and S32 biases upward, it is easy to move the caster CT onto the inclined surface PLS. This urging force acts in a direction to return the load detection unit 100M to the accommodation position shown in FIG. 3, and in the state shown in FIG. 4, as shown by the arrow B, the first and second

rear arms

81, 82 acts in a linear direction connecting the

rear ends

81r, 82r and the

front ends

71f, 72f of the first and second

front arms

71, 72.

In addition, in order to make the movement of the caster CT onto the inclined surface PLS easier, the load detecting unit 100M may be brought closer to the caster CT in a state where the inclined surface PLS is in contact with the caster CT (FIG. 6).

When the caster CT climbing on the inclined surface PLS and rising on the inclined surface PLS reaches a predetermined position on the weighing pan PL, the first and second

rear arms

81 and 82 come into contact with the convex portion p12 of the housing portion HS. , Pivoting is limited. As a result, the backward movement of the caster CT is also restricted, and the caster CT stops at a predetermined position on the weighing pan PL.

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

Since the load detection unit 100 of the present embodiment connects the bed BD as a subject and the load detection unit 100M including the load detector via the link mechanism 100C, the load detection unit 100M is connected to the caster of the bed BD. The caster CT can be easily placed at a position suitable for placement of the CT, and the caster CT can be easily placed on the weighing pan PL.

The load detection unit 100 according to the present embodiment can be integrally attached to the bed BD that is a subject, and when the load detection unit 100M is not used, the load detection unit 100M is held at a separated position below the floor plate fb of the bed BD. can do. Further, the load detection unit 100M held under the floor plate fb of the bed BD does not hinder the movement of the bed BD. Therefore, according to the load detection unit 100 of the present embodiment, it is not necessary to store the load detection unit 100M (load detector) in a separate storage location, and up to the intended use position where the load detection unit 100M (load detector) is used. , And can be moved together with the bed BD.

By fixing the load detection unit 100 of the present embodiment to the rotating column rp of the bed BD in a state where the front-rear direction of the load detection unit 100 and the traveling direction of the caster CT coincide with each other, the direction of the caster CT is directed. Even in the case, the load detection unit 100M can always be positioned in the traveling direction of the caster CT. Therefore, when the caster CT is placed on the weighing pan PL of the load detection unit 100M, the load detection unit 100M (load detector 100M) is moved forward of the caster CT by simply sliding the load detection unit 100M downward and forward. ) Can be arranged.

In the load detection unit 100 of the present embodiment, when the caster CT is placed on the inclined surface PLS of the weighing pan PL, a biasing force that biases the caster CT upward works. Therefore, according to the load detection unit 100 of the present embodiment, the caster CT can be easily introduced onto the weighing pan PL.

In the load detection unit 100 of the present embodiment, when the caster CT reaches a predetermined position on the weighing pan PL, the first and second

rear arms

81 and 82 come into contact with the convex portion p12 of the housing portion HS, and the first 1. The pivoting of the second

rear arms

81 and 82 and the movement of the caster CT are restricted. Therefore, the caster CT introduced onto the weighing pan PL can be stopped at an appropriate position on the weighing pan PL only by providing the convex portion p12 appropriately.

In the load detection unit 100 of the present embodiment, the link mechanism 100C including the first link L1 and the second link L2 is provided on both sides in the width direction of the attachment portion 100A and the load detection portion 100M. The shift in the width direction with respect to the detection unit 100M is suppressed.

<Modification>
In the load detection unit 100 of the present embodiment, the following modification can be used.

The attachment position of the attachment portion 100A with respect to the subject can be arbitrarily selected as long as the subject can be appropriately arranged on the weighing pan PL. For example, when the subject is the bed BD shown in FIG. 2, the attachment portion 100A may be attached to the beam bm. At this time, the load detection unit 100 is not able to rotate around the central axis X _rp caster CT integrally, it is possible to match the travel direction of the caster CT in the longitudinal direction of the load detection unit 100. If necessary, for example, an extension beam (not shown) extending in the longitudinal direction or the short side direction of the bed BD may be newly attached to the beam bm of the bed BD, and the attachment portion 100A may be attached to the extension beam. .

In the load detection unit 100 of the above embodiment, the receiving portion 61 of the mounting portion 100A is a mechanism for continuously fixing the load detection unit 100 to the subject over a long period of time. It is not limited to. The receiving unit 61 may be a mechanism for appropriately attaching and detaching the load detection unit 100 to / from the subject, and may be, for example, a clip, a vise, a magnet, or the like. Alternatively, when no upward force is applied to the mounting portion 100A due to the configuration of the link mechanism 100C, the load detection unit 100 is covered by covering the receiving portion 61 from above the subject (for example, the beam bm of the bed BD). Can also be attached to the subject.

Instead of the beam bm extending in the longitudinal direction of the bed BD, a bed having a beam extending in the short direction of the bed and connecting two casters CT arranged in the short direction, or having no such beam, vertically below The load detection unit 100 can be attached as appropriate even in a bed in which casters are provided at the lower ends of the four legs that extend. The subject is not limited to a bed or a medical device.

In the load detection unit 100 of the above embodiment, the link mechanism 100C includes the first link L1 including the first front arm 71 and the first rear arm 81, and the second link including the second front arm 72 and the second rear arm 82. It is not restricted to the aspect which has 2 links L2. The link mechanism 100C is a mechanism that connects the mounting portion 100A and the load detection unit 100M so as to be relatively movable in the front-rear direction and the vertical direction, and can move the load detection unit 100M between the separation position and the detection position. Any mechanism may be used. Moreover, it is not essential to link on both sides in the width direction of the attachment portion 100A and the load detection portion 100M, and it may be linked only on one side in the width direction.

The load detection unit 100 of the above embodiment may not have torsion springs S11, S12, S21, S22, S31, and S32. In this case, the load detection unit 100M can be held at the separated position by an arbitrary lock mechanism such as an engagement / disengagement unit or a magnet provided in the first link L1, the second link L2, the housing unit HS, or the like.

In the load detection unit 100 of the above embodiment, instead of the convex portion p12 of the housing portion HS, a connecting portion between the first and second

front arms

71 and 72 and the first and second

rear arms

81 and 82 and / or Alternatively, a convex portion is provided at the connecting portion between the first and second

front arms

71 and 72 and the mounting portion 100A, whereby the first and second

front arms

71 and 72, the first and second

rear arms

81 and 82 are provided. The rotation of the caster CT to which the mounting portion 100A is attached may be restricted.

In the load detection unit 100 of the above-described embodiment, the placing plate PL of the load detection unit 100M may not have the inclined surface PLS.

<Load detector>
Next, as a specific example of the load detector included in the load detection unit 100M of the first embodiment, a load detector LD shown in FIGS. 7 and 8 will be described.

As shown in FIGS. 7 and 8, the load detector LD includes first and

second base portions

11 and 12, and beam-shaped first and second load cells 21 connected to the first and

second base portions

11 and 12, respectively. , 22 and the mounting table 3 supported between the first and

second load cells

21, 22 by the first and

second load cells

21, 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 LD, and the inclined surface 3S of the mounting table 3 is provided in the longitudinal direction. The side is the front side.

The first base portion 11 is a member that cantilever-supports the first load cell 21, and a flat plate portion 11a whose planar shape is substantially the same shape as the first load cell 21, and a support that protrudes upward from the rear end of the flat plate portion 11a. It has the base part 11b.

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 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 that penetrate in the vertical direction are formed. The rear end 21 ss of the strain body 21 s 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.

In the vicinity of the front end 21sf of the strain body 21s, two screw holes Th penetrating in the vertical direction are also formed. 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).

In the vicinity of the front end 22ss of the strain body 22s, two screw holes Th penetrating in the vertical direction are formed. A front end 22ss of the strain body 22s is fixed to the support base 12b of the second base 12 via a screw T and a 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.

Also in the vicinity of the rear end 22sf of the strain body 22s, two screw holes Th penetrating in the vertical direction are formed. 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 the 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 detecting a load using the load detector LD. The mounting table 3 includes a plate part P (FIG. 7) 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 provided on the wall part W. Part C2 (FIG. 8).

The plate part P has a rectangular shape with the longitudinal 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 concave portion R is provided at a position that restrains the subject on a line segment L connecting the mounting positions A1 and A2 (FIG. 9) of the mounting table 3 to the first and

second load cells

21 and 22. ing.

7 and 8, an inclined surface 3S is provided in the front region of the plate portion P. As shown in FIG.

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.

A first connecting portion C1 having a plate shape parallel to the plate portion P is provided on the outer surface of the first protruding portion WL1p. 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. 7, FIG. 8).

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 of the load detector LD, 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. 7). FIG. 8). As shown in FIG. 9, 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.

When the load detector LD having the above-described configuration is used as a load detector in the load detection unit 100M of the load detection unit 100 of the above-described embodiment, the first and

second bases

11 and 12, the first and second The

load cells

21 and 22 are accommodated in the accommodating portion HS. The mounting table 3 corresponds to the weighing pan PL. A caster that is positioned by restricting movement of the first and second links L1 and L2 (that is, relative movement between the mounting portion 100A and the load detecting portion 100M) by the convex portion (movement restricting portion) p12 of the housing portion HS. By matching the position of the CT and the position of the recess R on the mounting table 3, the caster CT can be positioned and restrained on the weighing pan PL (mounting table 3) more suitably.

The first rear arm 81 of the load detection unit 100 is connected to the housing portion HS in the vicinity of the first load cell 21 of the load detector LD housed in the housing portion HS and is parallel to the first load cell 21 in plan view. The second rear arm 82 extends and is connected to the accommodating portion HS in the vicinity of the second load cell 22 of the load detector LD accommodated in the accommodating portion HS and extends in parallel with the second load cell 22 in plan view. The longitudinal direction of the load detector LD coincides with the longitudinal direction of the load detection unit 100.

Here, the reason why the load detector LD supports the mounting table 3 at two points using the first load cell 21 and the second load cell 22 will be described.

In the load detector LD, as shown in FIG. 9, the mounting table 3 is supported in the vicinity of the front end 21sf of the strain body 21s of the first load cell 21 via the first connecting portion C1 so as to be vertically movable. The second load cell 22 is supported via the two connecting portions C2 in the vicinity of the rear end 22sf of the strain body 22s 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.

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. 10, 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.

In contrast, the load detector LD, as shown in FIG. 11, the longitudinal distance between the placement position PN and the mounting center A1 of the plate portion subject is placed on P table 3 x _P1 When 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 LD, even if the placement position PN moves in the front-rear direction, the sum of the deviation error due to the bending moment generated in the first load cell 21 and the deviation error due to the bending moment generated in the second load cell 22 is It is always substantially constant (a value of a predetermined ratio relative to the weight of the detection target). Therefore, for example, in the control unit (not shown), the detection values of the first load cell 21 and the second load cell 22 are added, and a predetermined value (a value of a predetermined ratio with respect to the weight of the detection target) is subtracted as an offset error. Thus, the load of the subject can be stably detected in a state where the influence of the deviation error caused by the bending moment is substantially removed.

Further, as shown in FIG. 11, the width direction of the distance between the mounting table 3 of the plate portion subject placed position PN and mounting centers A1 which is placed on the P y _P1, placing 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 LD, even if the mounting position PN moves in the width direction, the total of 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 is It is always substantially constant (a value of a predetermined ratio relative to the weight of the detection target). Therefore, for example, in the control unit (not shown), the detection results of the first load cell 21 and the second load cell 22 are added, and a predetermined constant value (a value of a predetermined ratio with respect to the detection target weight) is subtracted as an offset error. Thus, it is possible to stably detect the load to be measured in a state in which the influence of the deviation error caused by the torsional moment is substantially removed.

The load detector LD can be in the following deformation mode.

The 1st connection part C1 and the 2nd connection part C2 which the mounting base 3 of the load detector LD 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 load detector LD, the connection method of the support base portions 11b and 12b and the first and

second load cells

21 and 22 is arbitrary, and may be connected to the rear end surfaces of the first and

second load cells

21 and 22, for example. The connection between the first and

second load cells

21 and 22 and the mounting table 3 is the same.

In the load detector LD, 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 face each other with an angle smaller than about 5 °. May be. The number of strain gauges attached to each load cell is arbitrary.

In the load detector LD, the concave portion 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 load detector LD, the first connecting portion C1 of the mounting table 3 is attached in the vicinity of the front end 21sf of the strain generating body 21s of the first load cell 21, but the first connecting portion C1 of the mounting table 3 is the strain generating body 21s. What is necessary is just to attach to the front side (free end side) rather than the center of the longitudinal direction. Moreover, the 1st connection part C1 of the mounting base 3 can also be attached to the arbitrary positions of the free end side rather than the thin part 21th of the distortion 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 load detector LD, 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 load detector used in the load detector 100M of the above embodiment may be a single load cell type load detector 900 as shown in FIG. 10, and a load scale having three load cell sensors as shown in Patent Document 1. It may be. The load detector is not limited to a load detector having a load cell, and may be a load detector having various sensors such as a piezoelectric sensor and a displacement sensor.

Second Embodiment
A load detection system 500 according to the second embodiment will be described with reference to FIG. 13 as an example in which the load detector LD is used in the load detection unit 100M.

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

When using the load detection system 500, the four load detection units 100 are fixed to the rotating column rp of the bed BD so as to rotate integrally with the caster CT. In addition, you may prepare the bed for load detection to which the four load detection units 100 were attached previously.

After moving the bed BD to the intended use position, the four casters CT are mounted on the mounting table 3 of the load detector LD of the load detector 100M. Thereby, each of the four load detectors LD 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 detection units 100 adds the output from the first load cell 21 and the output from the second load cell 22 of each load detector LD 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 LD 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 detection unit 100 of the first embodiment, the same effects as the load detection unit 100 of the first embodiment can be obtained. In particular, by moving the bed BD so that the traveling directions of the four casters CT are aligned and then moving the bed BD in the traveling direction by installing the load detecting unit 100M on the floor surface F, the four casters CT 4 Mounting on one load detector LD can be easily performed.

In the load detection system of the present embodiment, the position, method, and the like for attaching the load detection unit 100 to the bed BD are arbitrary as long as the traveling direction of the caster CT can coincide with the front-rear direction of the load detection unit 100. . In the load detection system of the present embodiment, the number of load detection units 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 detection unit 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 load detection system of the present invention, the subject can be easily placed on the mounting table. 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 1st base, 12 2nd base, 21 1st load cell, 22 2nd load cell, 3 mounting table, 61 receiving part, 71 1st front arm, 72 2nd front arm, 81 1st back arm, 82 2nd Rear arm, 100 load detection unit, 100A mounting part, 100C link mechanism, 100M load detection part, 500 load detection system, BD bed, CT caster, F floor, HS housing part, LD load detector, L1 first link , L2 second link, P plate part, PL weighing pan, PLS inclined surface

Claims

A load detector including a mounting table for mounting the subject; and
An attachment part for attaching the load detection part to a part of the subject,
A link mechanism for connecting the load detection unit and the mounting unit;
The link mechanism is configured such that the load detection unit is installed on the floor and the subject is placed on the mounting table in a state where the attachment unit is attached to the subject. A load detection unit that moves between a detection position and a separation position where the load detection unit is separated from the floor surface.
The load detection unit according to claim 1, wherein the mounting table has an inclined surface, and the subject rolls on the inclined surface and is mounted on the mounting table.
At least one of the load detection unit, the attachment unit, and the link mechanism is provided with a movement restriction unit that regulates movement of the load detection unit beyond the detection position. The load detection unit described.
The load detection unit according to any one of claims 1 to 3, wherein a lower end portion of the mounting table is separated from the floor surface at the detection position.
The link mechanism is pivotally connected to the load detection unit and the mounting unit on both sides in a direction orthogonal to a moving direction in which the load detection unit and the mounting unit move relative to each other. The load detection unit according to any one of 1 to 4.
A recess is formed on the top surface of the mounting table,
The load according to any one of claims 1 to 5, wherein the concave portion is positioned on the mounting table of the load detecting unit at the detection position so that the subject enters the concave portion. Detection unit.
The load detection unit according to any one of claims 1 to 6, wherein the load detection unit includes a beam-type load cell that is cantilevered on a support table, and the mounting table is connected to the beam-type load cell.
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 detection unit according to claim 7, which is connected on the free end side of the beam-type load cell.
The load detection unit according to claim 8, wherein the first beam type load cell and the second beam type load cell are arranged in parallel.
Floor boards,
Legs supporting the floorboard;
A caster provided at the lower end of the leg,
A bed comprising the load detection unit according to any one of claims 1 to 9 attached to the leg portion,
The moving direction in which the mounting portion of the load detection unit and the load detection portion relatively move coincides with the traveling direction of the caster.
The caster is rotatable about a vertical axis;
The bed according to claim 10, wherein the load detection unit and the casters attached to the legs rotate integrally around the vertical axis.
A load detection system for detecting the load of a subject on a bed,
A plurality of load detection units according to any one of claims 1 to 9 attached to a leg of the bed;
A load detection system having a control unit connected to the plurality of load detection units and calculating the load of the subject based on an output of the load detection unit.