JP3534905B2 - Load cell for health meter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strain gauge type load cell applied to a very small health meter on which a person can rest on one foot.

[0002]

2. Description of the Related Art As a conventional digital type health meter, even if it is small, the mounting area is such that both feet can be mounted on the mounting table. However, although a health meter that puts one foot on it can be seen as a foreign product, it has to support the weight, so the area of the platform is made small and the height of the load cell is made high to maintain its strength. Therefore, it was unstable and difficult to balance when a person placed on the platform. Therefore, a device devised as a load cell whose height is lowered by high-weight measurement is disclosed in Japanese Utility Model Publication No. 5-9624. In this invention, as shown in FIG. 4, a thick strain-flexing portion is attached between an upper load-receiving plate and a lower base plate, and the load-receiving plate and the base plate are attached to each other with respect to the vertically varying position of the strain-flexing part. The height of the load cell is reduced by forming grooves so as not to contact each other.
Also, a load cell devised by using a single leaf spring material having a rectangular shape is disclosed in Japanese Utility Model Laid-Open No. 4-30449.
As shown in FIG. 5, this device has an L
Two cut grooves of a rectangular shape and an inverted L shape are provided so as to face each other, the central portion is used as a strain generating portion, and the two side pieces of the concave member on both sides thereof are used as load portions to form an extremely thin load cell.

[0003]

However, the structure shown in FIG. 4 has three Z-shaped layers, and since each layer is of the separable type, it requires assembly to be used as a load cell. There was a problem that it was difficult to make it extremely thin. Moreover, although the one shown in FIG. 5 can be made extremely thin,
Originally, as shown in FIG. 2 of the publication, the purpose is to form a thin platform scale using four load cells.
In order to make a weighing machine with one load cell, four cutting grooves are provided, so it is necessary to increase the plate thickness in order to bear the weight, and when trying to reduce the platform area, the groove width must be narrowed. Without it, processing becomes difficult. In addition, since the mounting part, strain-flexing part, and fixing part are formed of one plate material, there is a planar deviation between the load point and the fixing part that supports it, which is uneven when viewed from the ratio of the mounting area. There is a problem that the accuracy is adversely affected when a load is applied. Therefore, in the present invention, the mounting area is reduced to the extent that one foot of a person can be mounted, and the height is lowered as much as possible while maintaining the rigidity to support the weight, and the load point and the fixed point are made to substantially coincide with each other. The purpose of the present invention is to provide a microminiature load cell that is not affected by an unbalanced load when a person rests on one foot.

[0004]

According to a first aspect of the present invention, one elastic plate member is bent in a U-shape from the center, and its upper surface serves as a loading table, and its lower surface serves as a fixing portion, and L is attached to the above-mentioned table. Shaped and inverted L-shaped grooves are provided symmetrically, and strain gauges are attached to the back surface or front surface of the center of the two grooves as strain generating parts, and at four locations near the four corners outside the grooves. On the other hand so that the strain gauge can be easily attached to the central part of the above-mentioned fixed part, and the fixing legs are attached to the places near the four corners of the outside, just below the above-mentioned load point. It is characterized in that a very small load cell is constructed by providing screw holes so that the load cell can be installed.

According to a second aspect of the present invention, a notch is provided in the central portion of one rigid plate member so that the strain gauge can be easily attached to the strain-flexing portion, and one end adjacent to the notch is processed into a concave shape to form a concave shape. The lower surface has a convex shape, and screw holes are provided near the four corners of the outer side so that the fixing legs can be attached almost directly under the load point. On the other hand, one elastic plate material is symmetrical with L-shaped and inverted L-shaped grooves. The strain gauge is attached to the back surface or the front surface of the two grooves using the central portion, which is the inner side of the two grooves, as the strain generating portion, and the four points near the four corners outside the two grooves are positioned as load points. As a mounting base by welding and fixing the one end lower surface of the central portion on the notch side of the two grooves to the convex surface,
It is characterized in that it constitutes an integral load cell.

[0006]

When a load is applied to the mounting table, in a load cell in which one elastic plate member is bent in a horizontal U shape from the center, the vicinity of the bending start point is used as a fulcrum, and one rigid plate member is used as a fixed portion, and another plate is used. Weld the lower surface of the mounting base to the convex surface of the fixed part using the elastic plate material of as a mounting base, and in the integrated load cell, the strain generating part of the central part bends around the welding part as a fulcrum, and the strain gauge attached to the strain load A proportional output signal is sent, but even if it is placed on the mounting table with one foot, the height is made low and the position of the load point and the fixed leg match so that they are mounted in good balance and there is little measurement error and low price It is possible to realize a very small load cell.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the first invention is shown in FIGS. 1 is a perspective view of the whole, FIG. 2A is a plan view, FIG. 2B is a front view, and FIG. 2C is a bottom view. As shown in these drawings, in the load cell according to the present invention, one plate material serving as an elastic body is bent in a lateral U shape, and the upper surface thereof serves as a mounting table 1 and the lower surface serves as a fixing portion 2. The above-mentioned table 1 is provided with grooves 3 and 3'of L-shape and reverse L-shape symmetrically, and a strain gauge 8 is attached to the back surface or front surface of the central portion, and an output proportional to the load on the mounting table is transmitted. It is supposed to be done. In addition, 4 at the positions near the four outer corners of the L-shaped and inverted L-shaped grooves of the above-mentioned stand 1.
The four load points 4 are positioned so that the lower surface of the mounting table cover (not shown) is in contact. On the other hand, the central portion of the fixed portion 2 is provided with notches 9 so that the strain gauge 8 can be easily attached when the strain gauge 8 is attached to the back surface of the mounting table 1, and it is not shown in the drawings near the four corners of the outside, which are almost directly below the load point 4. There are four mounting screw holes 7 for the legs. Therefore, when a load is applied to the mounting table 1, the central strain generating portion 5 bends around the right end 6 of the mounting table as a fulcrum, and after being output from the strain gauge and processed by the CPU via the A / D converter as described above. The digital weight is displayed. As mentioned above, since the load point and the fixed leg are almost on the same line near the outer circumference,
It is well balanced against unbalanced loads, and is particularly effective for a weighing machine with such a small platform. Reference numeral 10 denotes an insertion groove for a tool for removing the undercut claw protruding from the mount cover to remove it from the mount 1. Although 7 is a screw hole, the leg may be fixed with a bolt and a nut as a bolt hole.

An embodiment of the second invention is shown in FIG. Figure 3A
Is a plan view, FIG. 3B is a front view, and FIG. 3B ′ is X- in FIG. 3A.
The X ′ sectional view and FIG. 3C are bottom views, respectively. As shown in these drawings, the load cell according to the present invention, the upper surface of the elastic plate member is a mounting table 1, the lower surface is a fixing portion 2, and the above-described table 1 is provided with grooves 3 and 3'of an L shape and an inverted L shape. The strain gauges 8 are provided symmetrically, and a strain gauge 8 is attached to the back surface or front surface of the central portion so that an output proportional to the load on the mounting table is transmitted. Further, four load points 4 are positioned at positions near the four outer corners of the L-shaped groove and the inverted L-shaped groove of the above-described base 1, and the lower surface of the mounting base cover (not shown) is in contact therewith. Further, the two convex portions 11 are welded to each other so that the mounting table 1 and the fixed portion 2 become an integral load cell. On the other hand, the central portion of the fixed portion 2 is provided with notches 9 so that the strain gauge 8 can be easily attached when the strain gauge 8 is attached to the back surface of the mounting table 1, and it is not shown in the drawings near the four corners of the outside, which are almost directly below the load point 4. Four mounting screws 7 for the legs are provided. Further, one end adjacent to the end of the notch 9 is subjected to a cutting process so that the upper surface has a convex shape 11 and the lower surface has a concave shape 12. The height a is set to be a clearance of the stopper against an overload. Therefore, the situation in which a load is applied to the platform 1 and other aspects are the same as in the above-described first invention.

[0009]

EFFECT OF THE INVENTION A structure in which one plate material is bent in a horizontal U shape,
The upper and lower plates are welded together to make them integral, but the structure is relatively simple, such as the structure in which one plate is machined to form a gap between the upper and lower plates. Since there are two, the strain area and load area can be made large compared to the overall size, so thin plate materials can be used, and the load cell bent into a U-shaped cross and the load cell welded with two plates have the same height. Can be lowered. Moreover, since the load point and the fixed leg are almost coincident with each other and can be located near the outer circumference, even if one foot is placed on the platform and the weight is measured, the balance is very good and stable, and it is possible to manufacture at a low cost.

[Brief description of drawings]

FIG. 1 is an overall perspective view of an embodiment of the present invention.

FIG. 2 is a plan view A, a front view B and a bottom view C according to an embodiment of the present invention.

FIG. 3 is a plan view A, a front view B, a cross-sectional view XX ′ in FIG. 3A and a bottom view C according to another embodiment of the present invention.

FIG. 4 is a sectional view of another conventional load cell.

FIG. 5 is a perspective view of another conventional load cell.

[Explanation of symbols]

1 platform 2 Fixed part 3,3 'groove 4 load points 5 strain section 6 fulcrum 7 Leg mounting screw hole 8 strain gauge 9 notches 10 Tool insertion groove 11 Convex convex surface 12 Concave concave surface

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01G 3/14 G01L 1/22 G01G 19/44 G01G 3/12

Claims (2)

(57) [Claims] 1. An elastic plate material is bent in a lateral U shape from the center, the upper surface serves as a mounting table, and the lower surface serves as a fixed portion, and grooves of L-shaped and inverted L-shaped are symmetrically provided in the above-mentioned mounting, and Strain gauges are attached to the back surface or front surface using the center part of the two grooves as the strain generating part, and the four points near the four outer corners of the groove are the load points, while the notch is formed in the center part of the fixing part. Provided,
A load cell for a health meter, characterized in that legs of a fixed portion are attached to locations near the four corners on the outer side and substantially directly below the load point. 2. A rigid plate material is provided with a notch in the central portion thereof, and one end adjacent to the end of the notch is subjected to a narrowing process in which the lower surface is concave and the upper surface is convex, and four outer corners are provided. A leg of the fixed part is attached to a place that is almost directly under the load point in the vicinity to form a fixed part, and an L-shaped groove and an inverted L-shaped groove are symmetrically provided on one elastic plate material. A strain gauge is attached to the back surface or front surface with the side center part as the strain generating part, and the four points near the outer four corners of the groove are set as load points, and the lower surface of one end of the center part on the cutout side of the two grooves is A load cell for a health meter, characterized in that it is a mounting table that is welded and fixed to a convex surface of the fixing portion that has been subjected to a narrowing process.