JPS623698Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a platform scale suitable for measuring relatively small loads such as mail.

In conventional platform scales, a lever is used as a load receiving mechanism, and load transmission is generally formed by a blade and a blade receiver. However, such a conventional structure has drawbacks such as requiring many man-hours to process the parts, requiring high accuracy, and requiring additional processing to increase hardness.

This invention was devised in view of these points, and the purpose is to obtain a platform scale that can transfer the load of the object to be measured on the tray to the transducer with high precision using the tray frame. be.

This idea uses the center point where a plurality of arms gather as a load application part to the transducer, and each arm forms a load receiving part from a receiving plate, and an elastic support with a fulcrum part at the end of the arm. The lever ratio is provided so as to be adjustable in position, so that the lever ratio can be adjusted very easily and accurately, and a highly accurate one can be obtained with a simple structure.

An embodiment of this invention will be described based on the drawings. First, a base 1 is formed by either sheet metal processing or casting, and a thin electrical resistance type load cell 2, which is a transducer, is fixed at the center of the bottom of the base 1. Next, a saucer frame 4 having four arms 3 is provided with an elastic support body, which will be described later, interposed therebetween.
A flexible portion 5 that elastically bends in the vertical direction is present in the center of the saucer frame 4, and ribs 6 are folded over and integrally formed on the arm 3 to provide sufficient rigidity. . A pin 7 serving as a load application section that applies a load to the load cell 2 is fixed at the center of the flexible section 5 . Further, recesses 8 serving as load receiving portions are formed at certain positions from the pins 7, respectively. moreover,
A long oval hole 9 is formed at the end of the arm 3 along its longitudinal direction.

An elastic support 10 bent into a U-shape is attached to the end of the arm 3. The upper surface 11 of these elastic supports 10 has a screw hole 1 into which a screw 12 that fits into the oval hole 9 is screwed.
3 is formed, and a screw hole 15 for a screw is formed in the lower surface 14. Then, the upper surface 11
The lower surface 14 is connected to a vertical wall 18 via bent portions 16 and 17, and this vertical wall 18 is used as a fulcrum. Then, the elastic support 10
is attached to the base 1 with a spacer 19 interposed therebetween, and the base 1 has an oval hole 21 into which a mounting screw 20 is inserted.

Next, steel balls 22 are placed in the recess 8, and a saucer 23 is placed on top of these steel balls 22. A ring 24 is fixed to the lower surface of the saucer 23 to prevent the steel balls 22 from rolling.

Further, two openings 25 are formed in the saucer 23, an interference plate 27 having holes 26 is attached to the inner surface of these openings 25, and a bolt 28 screwed to the base 1 is inserted into the opening. Hole 25 and hole 26
The head 29 faces the interference plate 27. Further, a compression spring 30 is provided between the base 1 and the saucer 23 to bias the saucer 23 upward.

Note that 31 is a display unit that displays data such as weight.

In such a configuration, when an object to be measured is placed on the tray 23, its weight is distributed and applied to each of the four steel balls 22, and the load is concentrated on the pin 7 according to the lever ratio by the arm 3. As a result, a load is applied to the load cell 2 and weighing is performed.

Now, when the distance from the recess 8 to the vertical wall 18 is a, and the distance from the recess 8 to the pin 7 is b, the load applied to the recess 8 in one arm 3 is the load acting on the load cell 2. is a/
It is multiplied by the ratio a+b. Therefore, this ratio is required to be equal in all arms 3. Therefore, if the position of the elastic support body 10 is changed by loosening the screw 12 and the mounting screw 20, the position of the vertical wall 18 will change, and a/a+
The ratio b can be adjusted as appropriate. Therefore, by setting a constant lever ratio for all the arms 3, accurate measurements can be made no matter where the object to be measured is placed on the tray 23.

Note that the angle of the bent portions 16 and 17 changes depending on the load at the vertical wall 18, which serves as a fulcrum during measurement, but the amount of deformation at the pin 7 is originally extremely small because the weighing medium is the load cell 2. Even if the vertical wall 18 has a small inclination, it does not pose any problem in actual measurements. Further, since the flexible portion 5 is gently curved and its curvature is small, the force required for deformation stress does not pose a particular problem. moreover,
The spacer 19 may not be provided, and its movement may be fixed to the base 1 or movable.

As mentioned above, this idea provides a transducer such as a load cell with a saucer frame in which multiple arms extend radially around the load application part, and the arms of the saucer frame receive the load of the saucer. Elastic supports, which form load receiving parts and have fulcrum parts at the ends of these arms, are arranged along the longitudinal direction so that their positions can be adjusted freely, so that the lever ratio is constant for all arms. This makes it possible to perform accurate measurements no matter where the object to be measured is located on the tray.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a perspective view of the whole, FIG. 2 is a plan view with the saucer removed, and FIG. 3 is a vertical cross-sectional side view taken along the - line in FIG. 2 including the saucer.
FIG. 4 is a partially enlarged sectional view, FIG. 5 is an exploded perspective view of the saucer frame and the elastic support, and FIG. 6 is a partially enlarged sectional view showing the load transmission structure between the saucer and the saucer frame. FIG. 7 is a partially enlarged vertical sectional side view showing the catch mechanism. 2...Load cell (transducer), 3...
...Arm, 4...Saucer frame, 7...Pin (load applying part), 8...Concave part (load receiving part), 10...Elastic support, 18...Vertical wall (fulcrum part), 23...
saucer.

Claims (1)

[Scope of utility model registration request] A saucer frame is provided in which a plurality of arms are integrally formed in a radial direction around a load application part for a transducer that converts a load into an electrical signal, and the load of the saucer is applied to the middle part of the arms of this saucer frame. 1. A platform scale, characterized in that an elastic support body is formed with a load receiving part and has a fulcrum part at the end of the arm, and is connected to the arm so as to be adjustable in position along the longitudinal direction of the arm.