JPS6040929A - Single shaft load cell - Google Patents

Abstract

PURPOSE:To completely eliminate error caused by combination and to make the manufacturing cost low, by overlapping two L-shaped load bearings, whose cross section is square, in a square shape, and providing round holes which penetrate both bearings at the intermediate part of the height of the square shape. CONSTITUTION:A circular cylinder shaped intermediate beam 10 has coupling parts 18' and 18'', whose inserting lengths are regulated by step surfaces 16' and 15'' at both ends. L-shaped load bearings 20' and 20'', whose shapes are the same and cross sections are square, are provided on both sides of the intermediate beam 10. Round holes 22, which are pressed onto the coupling parts 18' and 18'' of the intermediate beam 10 so as to form a unitary body, are provided at the intermediate parts of hexagonal plates 21. Gap 24' and 24'' at the free ends of the load bearings of the load cell are provided at the upper and lower parts to a central line 26 of the width of the hexagonal bodies. In this constitution, error due to combination can be completely eliminated, and the manufacturing cost can be made low.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a uniaxial load cell that accurately and inexpensively detects a varying uniaxial load opposing each other along a single straight line.

In order to avoid errors caused by changes in the point of application of the load, it is common to use an S-shaped uniaxial load cell that uses a shear type detection beam and has folded load bearings at both ends symmetrical to the beam center. .

In order to produce this S-shaped load cell with high pressure sensitivity and at low cost, the present invention uses a cylindrical beam as the intermediate shearing beam, which serves as the basis, and has a rectangular cross section with a through hole at the center of the height of both ends. By making the support separately, a U concentric with the center hole is formed on the intermediate outer shape of the intermediate cylindrical beam having a through cylindrical hole in the center.
A half-section annular groove is made by lathe, making it easy to harden and thereby simplify the stress concentration design calculation. By press-fitting the cylindrical shape of the intermediate beam into the hole, the three components are accurately configured into an integrated S-shaped uniaxial load cell.

Due to this structure, the cargo holders at both ends are the same shape and are L-shaped, so when stacked on top of the mouth, it becomes a square. Therefore, for a square material cargo holder, a through hole should be provided in the middle of the height, and 7 grooves should be inserted between the left and right sides. It is possible to form two load drains of the same exact L-shape, which are fitted and connected on a circular surface by one cylindrical beam. The final dimensions of this S-shaped uniaxial load cell are symmetrical, there are no errors due to compounding, and manufacturing is inexpensive.

Since the important intermediate beam, which is the basis of such a structure, and the load basins at both ends are manufactured separately, it is much easier to manufacture than the more complicated 8-cell load cell. Since they are fitted and integrated on the cylindrical surface, the accuracy of the final assembled product is higher than that of the integrated S load cell. Also, since the load-bearing and intermediate beams are separated, stress concentration areas of the intermediate beams and middle J1. ? The diameter of the hole can be modified by polishing, etc., making mass production possible, which is the most difficult task in producing load cells.

Preferred dormitory examples will be described below with reference to the drawings.

In Fig. 1O, an annular groove 14 with a U-shaped cross section concentric with the hollow hole 12 is turned on the outer surface of the intermediate beam, and stepped surfaces 1 at both ends of the intermediate beam are formed.
Fitting portion 18' whose insertion length is regulated by 6' and 16''
, 18'.

The 20'20' on both sides have the same shape of square cross-section and are load-bearing, and the fitting part 18'18' of the intermediate beam 10 shown in FIG. After providing a round hole 22 that can be press-fitted and integrated into the load cell shown in FIG. 2, the load cell load water shown in FIG. By providing a separate square hole 28 perpendicular to the plane of the paper in Figure 2, the load bearing is completely identical to the L-shaped load bearing 20' 20, which is symmetrical to the center hole 22.
'' can be formed.However, the load bearing shown in Figure 120
``A role 16'' that regulates the length that fits into the 20'' intermediate beam
16' is deleted, and the load bearings 20' and 20' at both ends are press-fitted into the intermediate beam 10 at an insertion length of 1 length, and the strain body of the S-shaped uniaxial load cell is finally assembled into one piece. .

As shown in the dotted line in Figure 3, when the load is applied along the line 26 after bonding, a shearing force is generated at the center of the U-shaped groove, and a tensile force is generated on one side and the other of the orthogonal crossed gauges. If you build an electric bridge with the opposite side, you can measure the shear force with high sensitivity. Moreover, since the load is applied close to the middle between the two load supports and the cross gauge detects only the shearing force, there is an advantage that bending moment errors that vary depending on the point of application of the load do not occur.

In addition, since the intermediate beam is a cylindrical beam and the strain gauge is bonded to the side surface of the hollow hole, both ends of the hollow hole can be sealed to protect the gauge, and according to the present invention, the intermediate beam can be manufactured easily as described above. The load cell can be made from a single rectangular material without any waste, and the load cell is inexpensive.

The intermediate beam 10 and the two load bearings can be press-fitted into one body, such as strong pressure, serration force press-fit, or shrink fit. Changes in the ridge load range are free outside the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is an exploded view of the load cell components of the present invention, FIG. 2 is a processed view of the load-bearing raw material, and FIG. 3 is a perspective view of the assembled load cell. In the figure 10 Intermediate beam 12 Hollow hole 1616' of intermediate beam 18'18' Intermediate beam load bearing is fitting part 20' 20
' Load bearing 21 Load bearing is the raw material for manufacturing 22 Fitting hole in the middle beam of load bearing 24'24'' Load bearing is the clearance groove at the free end 26 Load bearing is the center line of the raw material 28 Load bearing is a separated square hole

Claims (1)

[Claims] 1) Two L-shaped load bearings with a square cross section are stacked in a mouth shape, and a round hole passing through them is provided in the middle of the height of the mouth. A single-axis load cell with a cross gauge on the middle side.