JPH053956U - Structure of cylindrical load cell body - Google Patents

Abstract

(57) [Summary] [Purpose] A load cell body that is easy to store in a cylindrical outer case and suitable for low load range measurements is made. [Structure] The load cell main body 10 is made of a cylindrical material and is divided into an upper portion and a lower portion. Fixed part 17 and load receiver 18
Are formed in the upper step portion while facing each other with the groove 16 sandwiched therebetween. Since the parallel beams 14 and 15 having a relatively long dimension are formed on the lower side so as to surround the cave 11, they are easily bent and the low load range can be accurately measured. Of course, it is easy to fit in a cylindrical outer case.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure of a cylindrical load cell body which is a low load range type and suitable for being housed in a cylindrical outer case.

[0002]

[Prior Art]

 Usually, many load cells have an externally cylindrical shape because of their installation location or commercial value, but the entire load cell body housed inside has a rectangular shape. The one used was a cylindrical one with a radial beam.

[0003]

[Problems to be solved by the device]

 However, needless to say, the rectangular shape will have a large outer shape when it is to be stored in a cylindrical outer case, and the cylindrical shape having a radial beam is easy to store and is not subject to unbalanced load. Although strong, the center of the beam is used as the load receiver and the circumference of the beam is used as the fixed part, so each radiation beam is considerably shorter than the radius, and as a result, the beam is strong and not suitable for low loads. If the radial beam is thinned in an attempt to do so, the heat generated by the strain gauge attached to the beam will be adversely affected and the accuracy cannot be improved.

[0004]

[Means for Solving the Problems]

 Therefore, the external appearance of the load cell body 10 is cylindrical, and the parallel lower beams 10 and 15 are formed on the lower step portion 10B of the column shape so that the longest possible beam can be taken in the disc. A fixed portion 17 connected to one end of each of the parallel beams 14 and 15 and a load receiver 18 extending beyond the center are formed on the inner surface of the base.

[0005]

[Action]

 Since the parallel beams 14 and 15 are formed by using the entire lower part 10B of the cylindrical material, the parallel beams 14 and 15 can be manufactured for a long time, and even if the beam thickness is not reduced, a low load can be obtained. The range is measured accurately. Further, since the combined parallel beams 14 and 15 are symmetrical with respect to the screw hole 18a, which is the point of attachment, the load is strong against an unbalanced load, and since the whole is columnar, it can be easily housed in a columnar outer case.

[0006]

【Example】

 Hereinafter, the present invention will be described with reference to the drawings. In the figure, 10 is a load cell body, which is made of a cylindrical material and has a substantially rectangular cave 11 (Figs. 2 and 3) having L and M on each side from the lower surface side to a depth of more than about half the thickness. ), And from the upper surface side up to about half of the thickness, the pair of prismatic recesses 12 and 13 are scraped off, leaving a central path whose width is narrower than one side L, parallel to the other side M, and longer than M. Further, a part of the outer peripheral surface is cut by a surface parallel to the other side M (side surfaces 14a and 15a are formed) to form the lower step portion 10B in which the rectangular parallel beams 14 and 15 are combined. The lengths of the prismatic recesses 12 and 13 may reach the outer peripheral surface.

Next, the fixing portion 17 and the load receiver 18 are separately formed by cutting the groove 16 at a position slightly left of the center (screw hole 18a) in the prismatic central path located at the center. The upper part 10A is formed. Therefore, as a general shape, the parallel beams I4, 15 surround the cave 11 in the lower step portion 10B, and the fixed portion 17 and the load receiver 18 face each other across the groove 16 in the upper step portion 10A. There is.

Here, reference numerals 14a-1 and 15a-1 (FIGS. 1 and 2) are connecting circular through holes provided on the side surfaces 14a and 15a, respectively, for an external force (load) applied to the load receiver 18. It is provided to concentrate the stress here. Reference numerals 17a and 17b (FIG. 3) are through holes provided in the fixing portion 17, through which fixing bolts for fixing the load cell body 10 to a base (not shown) are inserted. Reference numeral 18a (Fig. 1) is a screw hole, which is provided at the tip of the load receiver 18 so as to be at the center position of the cylindrical material. Although not shown, a load rod is connected here to allow external force (load). I am supposed to receive it. Numerals 19 (a to d) and 20 (a to d) are strain gauges attached to the upper and lower surfaces of the parallel beams 14 and 15, respectively, and the detected resistance change is guided to the outside by a lead wire (not shown). Detected by the electric circuit of.

At the time of measurement, when an external force (load) is applied to the position of the screw hole 18a of the load receiver 18, the parallel beams 14 and 15 which are relatively long-sensing parts are correspondingly generated. Since the resistance of the strain gauges 19 and 20 attached thereto is changed relatively even under a low load, the external force (load) can be known by detecting this change with a well-known bridge circuit. ..

At this time, even if the force deflected to the external force is mixed, the parallel beams 14 and 15 are symmetrically arranged around the force application point (screw hole 18a), and the strain gauges 19 and 20 are respectively arranged. Since the element is also symmetrical with respect to the force applied, if this relationship is applied to the opposite side of the bridge circuit, the effect of unbalanced load can be eliminated.

Needless to say, since the load cell body 10 has a columnar shape, it is easy to put it in a columnar outer case to make a product. Since the cave 11 is formed in 10B, it is possible to install a bellows in this portion to correct the pressure fluctuation inside the seal.

In the above description, the cylindrical upper and lower steps 10A and 10B are shown as having the same thickness (depth), but the strength of the fixing portion 17 and the load receiver 18 is self-deflecting (fixing portion). It is not necessary to have the same thickness, as long as there is no strength (including bending due to instability in mounting), it is sufficient. The cutting of the side surfaces 14a and 15a is convenient for calculating the bending amount of the parallel beams 14 and 15, but is not always necessary.

[0013]

[Effect of the device]

 As described above, in the present invention, the load cell is formed into a cylindrical shape, which can be divided into the upper part and the lower part, and a relatively long parallel beam can be installed in the lower part, which is suitable for measuring a low load range. Easy to store in a shaped container.

[Brief description of drawings]

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

FIG. 2 is a perspective view of the same embodiment as viewed from the back side.

FIG. 3 is a plan view of the same embodiment.

[Explanation of symbols]

 10 Load Cell Main Body 10A Upper Stage 10B Lower Stage 11 Cave 12 Square Cylinder 13 Square Cylinder 14 Parallel Beam 15 Parallel Beam 15 Parallel Beam 16 Groove 17 Fixing Part 18 Load Bearing 18a Screw Hole 19 (a-d) Strain Gauge 20 (a-d) Strain Gauge L one side M the other side

Claims (1)

[Claims for utility model registration] [Claim 1] From the bottom surface side of the cylindrical material, the sides are L and M
A substantially rectangular cave 11 made of is drilled to a depth slightly exceeding the lower end portion 10B, and a central path (16, 17, 18) narrower than one side L and parallel to the other side M from the upper surface side is formed in the upper step portion. A prismatic recess 1 longer than the other side M, leaving a depth of 10 A
Scraping Nos. 2 and 13 from the upper step 10A, the central road (1
6, 17, 18) has a shape in which a fixed portion 17 is separated on the left side and a load receiver 18 is formed on the right side by cutting the groove 16 at a position leftward from the center, and the overall configuration is the lower step portion 10B. The parallel beams 14 and 15 are attached to the upper portion 10A with the fixed portion 17,
A structure of a cylindrical load cell body, characterized in that a load receiver 18 is provided.