JPS5825312Y2 - Shock prevention device for load cell scales - Google Patents

Description

[Detailed description of the invention] This invention is a load cell scale that detects weight by changes in the electrical characteristics of a detection element such as a strain gauge attached to the load cell frame. This invention relates to an impact prevention device for a load cell scale that allows the weight of a loaded object to be accurately and reliably detected without applying impact.

Conventionally, a load cell is constructed by pasting a detection element such as a strain gauge on a load cell frame made of an elastic body, one end of the load cell frame is supported by a support member, and a movable end of the load cell frame is supported by a supporting member. When a weighing pan is attached and a load is placed on the weighing pan, the load cell frame and the detection element attached to it are distorted in accordance with the weight of the load, and the detection element corresponding to the amount of distortion is A load cell scale has been put into practical use that detects the weight of the load by converting changes in electrical characteristics into weight.This type of scale has a relatively simple configuration and is highly accurate. Moreover, since it is output as an electric signal, it has the advantage that it can be used universally in electronic digital display rods and the like.

In addition, there are cases where a load is thrown onto the weighing pan from an angle, or when a body or other object hits the periphery of the weighing pan. Impact loads may be applied.

However, although the load cell frame is made of an elastic body, it is made of a special material that has a small amount of displacement, so if an excessive impact acts directly on the load cell frame,
In some cases, the load cell frame may become permanently deformed, changing the performance of the load cell and making it impossible to reliably detect the weight of the load.

This idea was made to improve the above situation.
The purpose of this is that even if horizontal impact is applied to the weighing pan, etc., excessive impact will not be applied to the load cell frame, so the performance of the load cell will not change, and the loaded object will not be affected. It is an object of the present invention to provide a shock prevention device for a load cell type weighing machine that can always perform high-precision and reliable detection.

This invention will be explained below with reference to embodiments shown in the drawings.

In the figure, reference numeral 1 denotes a load cell, which is composed of a load cell frame 2 and a strain gauge 3 attached thereto.

That is, the load cell frame 2 is formed into a rectangular shape with a predetermined thickness, a rectangular hollow part is formed in the center thereof, and both sides of the upper and lower surfaces of the hollow part are cut in an arc shape. On the load cell frame 2 corresponding to this arc-shaped part,
A load cell 1 is constructed by attaching strain gauges 3 to four locations on both sides of the lower surface.

The four strain gauges 3 are electrically connected in a bridge circuit configuration so that electrical signals from the four strain gauges 3 are combined and output.

Four mounting grooves 6.7 are formed along the vertical direction near both sides of the upper and lower surfaces of the support end 4 side at one end of the load cell frame 2 and the movable end 5 side at the other end. Form.

Furthermore, both load cell support shafts 9 are fixed to the upper and lower plates of the U-shaped support plate 8, and the inwardly protruding portions of these shafts 9 are used to support the load cell frame 2 through washers 10. It is rotatably fitted into both numbered holes 6 on the end portion 4 side, and the center plate of the support plate 8 and the load cell frame 2 are spaced apart so that the load cell frame 2 is horizontal with the shaft 9 as a fulcrum. In addition, a rubber cushioning material 11 formed with a predetermined thickness is interposed in the gap between the load cell frame 2 and the support plate 9.

Similarly, both plate support shafts 13 are fixed to the upper and lower plates of the U-shaped plate mounting plate 12, and the inwardly protruding portions of these shafts 13 are connected to the load cell 1 with a washer 14 interposed. It is rotatably fitted into the numbering hole 7 on the side of the movable end 5, and the center plate of the mounting plate 12 and the load cell frame 2 are spaced apart, and the plate mounting plate 12 is mounted on the shaft 13 as a fulcrum. A rubber cushioning material 16 formed with a predetermined thickness is interposed in the gap between the casing, the load cell frame 2, and the mounting plate 12.

Further, the center portion of the lower surface of the scale plate 18 is fixed to the upper plate of the plate mounting plate 12 via a mounting base 17.

In the past, there were four holes on the inside of the four corners of the support plate 20, which was bent into a rectangular shape.
At the same time as fixing the book supports 21, another support plate 22 is fixed inside the support plate 20, and this support plate 22 is fixed.
Place the back to back on the support plate 8 in the center of the
Fix by 3.

Note that 24° and 25 in the figure are the upper and lower cases that cover the load cell 1, etc., and these two cases 24.
25 are attached to the upper and lower parts of the support column 21, respectively.

The state of use of the load cell scale configured as described above will be explained.

When a load is placed on the weighing pan 18, the weight of the load acts on the movable end 5 side of the load cell frame 2, causing a predetermined portion of the load cell frame 20 (near the arcuate cut portion) to be distorted, causing the adhesive to stick to this portion. The four strain gauges 3 attached are also distorted,
An electrical signal is output corresponding to this amount of strain, and since the four strain gauges 3 are connected in a bridge circuit format, these electrical signals are integrated, expanded, and output, and this electrical signal is The weight of the load is measured by converting the output amount into weight and displaying it.

During use, if a load is thrown onto the weighing pan 18 from an angle, or if a body or other object hits the periphery of the weighing pan 18, the weighing pan 18 may be subject to horizontal impact. When a load is applied, the load cell frame 2 uses the load cell support shaft 9 as a fulcrum, or the weighing plate 18 uses the plate support shaft 13 as a fulcrum.
rotates in the horizontal direction, and both cushioning rubbers 11.16
is pressed and deformed, and both rubbers 11 and 16 absorb the horizontal impact, and no excessive horizontal impact is applied to the load cell frame 2, so the load cell frame 2 does not suffer permanent deformation. The weight of the load can be detected reliably without changing the performance of the load cell 1 due to

In this embodiment, the horizontal buffer mechanism is provided on both sides of the load cell frame 20, but it may be provided on either side, and it goes without saying that the structure is not limited to the above embodiment.

As described in detail above, this invention supports at least one of the load cell frame or the weighing plate so as to be rotatable in the horizontal direction, and a buffer member is interposed in this support.
If a horizontal impact is applied to the weighing pan, such as when a load is thrown onto the weighing pan from an angle, or when a body or other object hits the weighing pan, the load cell frame or the weighing pan may be damaged. While at least one side rotates slightly, the impact is absorbed by the buffer member, and the load cell frame is not permanently deformed and the performance of the load cell does not change, and the load cell always maintains high accuracy. Therefore, the weight of the loaded object can be detected accurately and reliably.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of this invention, FIG. 2 is an exploded perspective view of the main parts of the same example, and FIG. 3 is a perspective view of a support member of the same example. 1... Load cell, 2... Load cell frame, 3... Strain gauge, 4...
Supporting end portion, 5... Movable end portion, 6... Mounting groove, 7... Mounting groove, 8... Support plate,
9... Load cell support shaft, 11... Cushioning rubber, 12... Book number plate, 13-...
・Dish support shaft, 16... Cushioning material rubber, 17...
...Mounting stand, 18...Weighing plate, 20...
- Support plate, 21... Support plate, 22... Support plate.

Claims (1)

[Scope of utility model registration request] one end of the load cell frame with a detection element such as a strain gauge attached at a predetermined position is supported by a support member, and a weighing plate is attached to the movable end of the load cell frame;
In a load cell type scale that detects the weight of the load by converting changes in the electrical characteristics of the detection element into weight when a load is placed on the weighing pan, the load cell frame housing or the weighing pan 1. A shock prevention device for a load cell scale, characterized in that at least one of the above is supported rotatably in a horizontal direction, and a buffer member is interposed in the supporting portion.