Load cell

Abstract

To provide a load meter in which an anchor head does not shift.SOLUTION: A load meter comprises: a substantially cylindrical pressure receiving body; and a substantially cylindrical anchor head guide provided on an outer periphery of the pressure receiving body and having an upper end surface located above an upper end surface of the pressure receiving body.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a load cell for measuring the tensile force acting on a ground anchor.

Background Art

[0002] A ground anchor is a system that stabilizes a structure by connecting a fixing part formed in the ground to a structure such as a formwork or a retaining wall provided near the ground surface with a high-strength tension member and using the tensile force acting on the tension member. A conventionally known ground anchor connects a fixing part formed in the ground and a structure via a tension member 101. Then, a tensile force is applied to the structure from a pedestal 104 formed on the structure via a fixing tool composed of an anchor head 102 and an anchor plate 103 provided at the head of the tension member 101 (FIG. 6).

[0003] There is concern that the tensile force acting on the ground anchor may decrease due to deformation of the installed ground or aging deterioration of the tension member or the like. Therefore, by measuring the tensile force acting on the ground anchor, it can be used as an index for ground deformation and the soundness of the ground anchor. Generally, the measurement of the tensile force is performed by measuring the load applied to a load cell 105 provided between the anchor head 102 and the anchor plate 103 with a strain gauge provided inside the load cell 105.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When a load cell 105 is installed between the anchor head 102 and the anchor plate 103, the axes (centers) of the anchor head 102 and the load cell 105 must be aligned in order to accurately measure the tensile force. In conventional designs, the anchor head 102 and load cell 105 are in contact on a flat surface, and there is a risk that the anchor head 102 and load cell 105 may shift during installation of the anchor head 102.

[0006] The present invention aims to provide a load cell that prevents the anchor head from shifting. [Means for solving the problem]

[0007] To achieve the above objective, the load cell of the present invention comprises a substantially cylindrical pressure-receiving body and a substantially cylindrical anchor head guide provided on the outer circumference of the pressure-receiving body, the upper end surface of which is positioned above the upper end surface of the pressure-receiving body. The pressure receiving body consists of a cylindrical body to which a sensor is attached to its inner surface, and a hollow disc-shaped pressure receiving cover provided on the upper part of the cylindrical body. The pressure receiving cover may have an inner circumferential cylinder that protrudes downward from its inner circumferential edge. A sensor protective material may be filled between the opposing inner circumferential cylinders and the inner circumferential surface of the cylindrical body. The pressure receiving body has an outer circumferential cylinder that protrudes downward from its outer edge, the outer circumferential cylinder is located on the outer circumference of the cylindrical body, the outer circumferential surface of the outer circumferential cylinder has a fitting groove that is continuous in the circumferential direction, and a fixing bolt that penetrates the anchor head guide from the outer circumference to the inner circumference and is screwed in, the tip of the fixing bolt that has penetrated the anchor head guide may be located within the fitting groove. The anchor head guide may be partially cut out to give it a roughly C-shape in plan view. [Effects of the Invention]

[0008] The present invention, by means of solving the above-mentioned problems, can achieve at least one of the following effects. (1) Since the anchor head fits within the inner diameter of the anchor head guide, the axis of the anchor head and the pressure receiving body do not become misaligned, making positioning during construction easy. (2) Since the fitting groove is provided continuously with the outer casing of the pressure-receiving cover, the anchor head guide can be fixed to the pressure-receiving body without having to precisely position it. (3) The cable outlet and cable fit into the notch of the anchor head guide, thus protecting the cable outlet and cable from the anchor head guide. [Brief explanation of the drawing]

[0009] [Figure 1] Perspective view of the load cell of the present invention [Figure 2] Cross-sectional view AA in Figure 1 [Figure 3] Exploded perspective view of the load cell of the present invention [Figure 4] Plan view of the load cell of the present invention [Figure 5] Diagram illustrating the use of the load cell of the present invention for a ground anchor. [Figure 6] Diagram illustrating a conventional ground anchor. [Modes for carrying out the invention]

[0010] The load cell of the present invention will be described in detail below with reference to the drawings.

[0011] (1) Configuration of the load cell (Figures 1-4) The load cell of the present invention is provided with a substantially cylindrical anchor head guide 2 on the outer circumference of the pressure receiving body 1.

[0012] (2) Pressure receiving body The pressure receiving body 1 consists of a cylindrical body 11 and a hollow disc-shaped pressure receiving cover 12 that is placed over the top of the cylindrical body 11. A sensor (strain gauge) S is provided on the inner circumferential surface of the cylindrical body 11. In this embodiment, the cable for the sensor S is routed upwards from a cable outlet 111 provided on the side of the cylindrical body 11. The pressure-receiving cover 12 is in the shape of a hollow disc, and has an inner peripheral cylinder 121 protruding downward from the inner peripheral edge and an outer peripheral cylinder 122 protruding downward from the outer peripheral edge. Also, on the upper surface of the pressure-receiving cover 12, there is a pressure-receiving portion 123 that contacts the lower surface of the anchor head 3. When the pressure-receiving cover 12 is placed over the cylindrical body 11, the inner peripheral cylinder 121 is spaced apart from the inner peripheral surface of the cylindrical body 11 by a predetermined distance and faces it, and the outer peripheral cylinder 122 is located on the outer periphery of the cylindrical body 11. A continuous fitting groove 124 is provided on the outer periphery of the outer peripheral cylinder 122. The pressure-receiving cover 12 is fixed by a pressure-receiving cover fixing bolt 125 that penetrates the outer peripheral cylinder 122 from the outside and is screwed into a female-threaded fixing bolt hole 112 provided in the cylindrical body 11. The head of the pressure-receiving cover fixing bolt 125 is housed in the fitting groove 124. A sensor protection material 13 made of resin is filled between the outer peripheral surface of the inner peripheral cylinder facing the inner peripheral surface of the cylindrical body 11.

[0013] (3) Anchor head guide The anchor head guide 2 is substantially cylindrical and is provided on the outer periphery of the pressure-receiving body 1. The upper end surface of the anchor head guide 2 is located above the upper end surface of the pressure-receiving cover 12 of the pressure-receiving body 1. The anchor head guide 2 is provided with bolt holes 21 at predetermined intervals on the outer periphery, screw holes 22 penetrating inwardly are provided at the bottom of the bolt holes 21, and a fixing bolt 23 that is screwed into the screw holes 22, penetrates the anchor head guide 2, and the tip is fitted into the fitting groove 124 of the pressure-receiving cover 12 is used to fix it to the pressure-receiving body 1. Since the fitting groove 124 is provided continuously on the outer peripheral cylinder 122 of the pressure-receiving cover 12, it can be fixed to the pressure-receiving body 1 without accurately positioning the anchor head guide 2. Also, in this embodiment, in order to take out the cable for the sensor S upward from the cable lead-out portion 111, a notch 24 is provided in a part of the anchor head guide 2, so that it has a substantially C-shaped cross-section in plan view. By accommodating the cable lead-out portion 111 and the cable in the notch 24, the cable lead-out portion 111 and the cable are protected by the anchor head guide 2.

[0014] (4) Ground anchor In the ground anchor using the load cell of the present invention, the anchor 4 is inserted through the load cell, and the upper part of the pressure receiving body 1 is clamped by the anchor head 3, which has the upper end of the anchor 4 fixed via a wedge 5, and the lower part is clamped by the anchor plate 6 through which the anchor 4 is inserted. The diameter of the anchor head 3 is such that it fits within the inner circumference of the anchor head guide 2. Then, the axial force from the anchor head 3 is received by the pressure receiving portion 123 on the upper surface of the pressure receiving cover 12 and transmitted to the cylindrical body 11, and the reaction force from the anchor plate 6 is received by the lower surface of the cylindrical body 11, and the resulting compressive force is measured by the sensor S. Since the anchor head 4 fits within the inner diameter of the anchor head guide 2, the axes of the anchor head 4 and the pressure receiving body 1 do not become misaligned, making positioning during construction easy. The anchor head 4 is not limited to the shape of this embodiment; conventional anchor head shapes can also be used. [Explanation of Symbols]

[0015] 1 Pressure receiving body, 11 Cylindrical body, 111 Cable outlet, 112 Fixing bolt hole, 12 Pressure receiving cover, 121 Inner circumference cylinder, 122 Outer circumference cylinder, 123 Pressure receiving part, 124 Fitting groove, 125 Fixing bolt, 13 Sensor protective material 2 Anchor head guide, 21 Bolt hole, 22 Threaded hole, 23 Fixing bolt, 24 Notch 3 Anchor head 4 Anchors 5 Wedge 6 Anchor plate

Claims

1. A load cell for measuring the tensile force acting on a ground anchor by receiving pressure on a substantially cylindrical anchor head, A roughly cylindrical pressure-receiving body equipped with strain gauges inside, The anchor head guide is provided on the outer circumference of the pressure receiving body and is substantially cylindrical, with its upper end surface positioned above the upper end surface of the pressure receiving body, and having an inner diameter capable of accommodating the anchor head. Load cell.

2. The pressure receiving body consists of a cylindrical body on which the strain gauge is attached to its inner surface, and a hollow disc-shaped pressure receiving cover provided on the upper part of the cylindrical body. The pressure-receiving cover is characterized by having an inner circumferential cylinder that protrudes downward from the inner circumferential edge. The load cell according to claim 1.

3. A sensor protective material is filled between the opposing inner circumferential cylinders and the inner circumferential surface of the cylindrical body, characterized in that The load cell according to claim 2.

4. The pressure receiving body has an outer circumferential cylinder that protrudes downward from its outer edge, The outer casing is located on the outer circumference of the cylindrical body. The outer surface of the outer cylinder has fitting grooves that are continuous in the circumferential direction. The anchor head guide has a fixing bolt that penetrates from the outer circumference to the inner circumference and is screwed in, The tip of the fixing bolt that passes through the anchor head guide is located within the fitting groove, characterized in that The load cell according to claim 3.

5. The anchor head guide is characterized by having a portion cut out to give it a roughly C-shape in plan view. The load cell according to claim 4.

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