JPH04328426A - Load cell scale - Google Patents

Abstract

PURPOSE:To maintain measuring accuracy at high degree by fixing a supporting frame for supporting a receiving pan for a material to be measured to the tip part of a load cell, fixing the base end part of the load cell to the housing of a main body, and providing stoppers at the supporting frame so as to face the housing. CONSTITUTION:A supporting frame 6 is fixed to a tip part 18 of a load cell 17. A base end part 16 is fixed to the lower surface of an upper plate of a main body housing 15. A receiving pan 8 is supported on buffer rubber pieces 7 at the four corners of the upper surface of the frame 5. Bolts 19 and 20 are penetrated through the four corners and the center of the frame 6. The bolts are made to face projections 21 and 22 of the upper surface of the upper plate of the housing 15 and made to be four-coner stoppers 23 and a load cell stopper 24. The tip part 18 and the frame 6 are linked by way of a through hole which is formed in the upper plate of the housing 15. Therefore, even if an excessive shock load is applied on the receiving pan 8, the load does not collide with the load cell directly, and the measuring accuracy of the load cell is maintained at the high degree.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a load cell scale in which a support frame for supporting a tray on which objects to be weighed are loaded is fixed to a movable tip of a single load cell whose base end is fixed to a main body housing. It is.

0002

2. Description of the Related Art In recent years, load cell scales that calculate the weight of articles as electrical data have been put into practical use. This load cell scale has a support frame fixed to the tip of a load cell whose base end is fixed to the main body housing, and this support frame supports a tray. Weighing is done by electrically measuring the strain that occurs in the load cell.

A conventional example of such a load cell scale will be explained based on FIGS. 3 and 4. First, in this load cell scale 1, a rectangular flat support frame 6 is fixed to a movable tip end 5 of one load cell 4 whose base end 3 is fixed on a rectangular flat main body base 2. Buffer rubber 7 attached to the four corners of the upper surface of this support frame 6
A saucer 8 is supported on top. In this load cell scale 1, four corner stoppers 11 are provided by the bolts 9 screwed into the four corners of the support frame 6 from above and the columnar members 10 erected on the main body base 2 facing each other. A bolt screwed into the bottom surface of the main body base 2 at a position opposite to the bottom surface of the tip end 5 of the load cell 4 serves as a load cell stopper 12 . In this load cell scale 1, the main body base 2 is attached to the bottom of the main body box 13 to form a main body housing, and the columnar housing is formed through various through holes formed on the upper surface of the main body box 13. The member 10 and the like are designed to protrude. Further, four bridge-connected strain gauges (not shown) are attached to the strain-generating portion of the load cell 4, and these strain gauges are connected to an arithmetic circuit (not shown).

With this configuration, in the load cell scale 1, when a strain occurs in the load cell 4 corresponding to the weight of the object to be weighed (not shown) loaded on the tray 8, the arithmetic circuit uses this distortion to adjust the weight of the object to be weighed. The weight is calculated electrically and used for displaying on a display (not shown) or printing on a label printer (not shown).

In the load cell scale 1 as described above, if an unbalanced load is applied to one of the four corners of the tray 8, the support frame 6 will be distorted and the tray 8 will collide with the top surface of the main body box 13. In order to prevent this, when one of the four corners of the saucer 8 descends beyond a certain value, the bolt 9 of the four corner stopper 11 comes into contact with the columnar member 10 to stop the descending. In addition, even if the load applied to the saucer 8 is uniform at the four corners, if it is excessive, the amount of strain in the load cell 4 will exceed the limit and plastic deformation will occur, so in order to prevent this, the tip 5 of the load cell 4 should be set at a certain value or more. When it descends, it comes into contact with the load cell stopper 12 and stops its descent. In this way, each stopper 11, 12 has a different purpose. For example, the distance between the bolt 9 of the four corner stopper 11 and the columnar member 10 is on the order of millimeters, whereas the distance between the load cell stopper 12 and the tip 5 of the load cell 4 is on the order of millimeters. The distance between them is on the order of microns, and if a uniform and excessive load is applied to the receiving tray 8, the load cell stopper 12 acts before the four corner stoppers 11 act.

[0006]

[Problems to be Solved by the Invention] In the load cell scale 1 described above, a part of the saucer 8 is partially damaged by the main body box 13 due to an unbalanced load.
The four corner stoppers 11 prevent collision with the
The load cell stopper 12 prevents the load cell 4 from being damaged due to impact loads, excessive loads, etc.

Here, since the load cell 4 is a precision instrument, even if plastic deformation due to excessive strain is prevented, the measurement accuracy will decrease if a direct impact is applied. However, in the load cell scale 1 described above, the load cell stopper 12 has a structure in which it directly contacts the tip 5 of the load cell 4. Therefore, in the load cell scale 1 described above, when an excessive impact load is applied to the saucer 8, the load cell stopper 12 collides with the load cell 4, resulting in a decrease in measurement accuracy, and its durability and reliability are decreased.

Furthermore, the functions of the above-mentioned stoppers 11 and 12 can be ensured by adjusting the spacing between the component parts. By rotating the hexagonal head 9a, which is the operated part of each bolt 9, the distance between the load cell stopper 12 and the columnar member 10 is adjusted. The spacing between the two is now adjusted.

However, since the hexagonal head 12a of this load cell stopper 12 is located on the bottom surface of the main body base 2, in order to operate it, the entire load cell scale 1 must be lifted and placed on a special support stand. These operations are complicated, and this hinders the productivity and maintainability of the load cell scale 1.

0010

[Means for solving the problem] The invention according to claim 1 includes:
The tray on which the object to be weighed is loaded is supported by a support frame, and this support frame fixes the load cell fixed at the movable tip to the main body housing at the base end, and the load cell stopper facing the main body housing is attached to the support frame. Established.

In the second aspect of the present invention, a load cell stopper made of a threaded body having an operated portion formed at one end thereof is screwed into the support frame from above to position the operated portion on the support frame.

0012

According to the first aspect of the invention, the load cell stopper comes into contact with the main body housing, thereby regulating the amount of distortion of the load cell due to an impact load or the like.

According to the second aspect of the invention, the operated portion of the load cell stopper, which is a screw body screwed into the support frame from above, is operated from above the support frame.

[0014]

[Embodiment] An embodiment of the present invention will be explained based on FIGS. 1 and 2. First, in this load cell scale 14, a support frame 6 is fixed to a tip end 18 of a load cell 17 whose base end 16 is fixed to the bottom surface of a top plate of a main body housing 15 whose bottom surface is open. A saucer 8 is supported on cushioning rubber 7 attached to the four corners. In this load cell scale 14, bolts 19 and 20, which are threaded bodies, are screwed into the four corners and the center of the support frame 6.
and protrusions 21 and 22 protruding from the upper surface of the top plate of the main body housing 15 face each other, thereby providing four corner stoppers 23 and a load cell stopper 24, respectively.

In this load cell scale 14, the tip portion 18 of the load cell 17 and the support frame 6 are connected through a through hole formed in the top plate of the main body housing 15. Furthermore, four bridge-connected strain gauges (not shown) are attached to the strain-generating portion of the load cell 17, and these strain gauges are connected to an arithmetic circuit (not shown).

With this configuration, in the load cell scale 14, when a strain occurs in the load cell 17 corresponding to the weight of the object to be weighed (not shown) loaded on the tray 8, the arithmetic circuit uses this distortion to adjust the weight of the object to be weighed. The weight is calculated electrically and used for displaying on a display (not shown) or printing on a label printer (not shown).

In the load cell scale 14 as described above, in order to prevent the saucer 8 from colliding with the main body housing 15 due to the bending of the support frame 6 due to unbalanced loads, the bolts 19 of the four corner stoppers 23 and the protrusions 21 are The contact restricts the partial descent of the saucer 8 to below a certain value. Furthermore, even if the load applied to the saucer 8 is uniform at all four corners, if it is excessive, the amount of strain on the load cell 17 will exceed the limit and plastic deformation will occur. The lowering of the tip portion 18 of the load cell 17 is regulated to a certain value or less by the contact. Note that each of the stoppers 23 and 24 has a different purpose as described above, so for example, the distance between the bolt 19 and the protrusion 21 of the four corner stopper 23 is on the order of millimeters, whereas the distance between the load cell stopper 24
The distance between the bolt 20 and the protrusion 22 is on the order of microns, and when a uniform and excessive load is applied to the receiving tray 8, the load cell stopper 24 acts before the four corner stoppers 23 act.

In this load cell scale 14, the bolts 20 attached to the support frame 6 and the main body housing 15
A load cell stopper 24 is provided with a protrusion 22 protruding from the side, and even if an excessive impact load is applied to the saucer 8, the components of the load cell stopper 24 will not collide with the load cell 17. Measurement accuracy is maintained at a high level, and the equipment has good durability and reliability.

Furthermore, in this load cell scale 14, when adjusting the interval between the components of each stopper 23 and 24 in order to ensure its function well, the receiving tray 8 is placed on the support frame 6.
Remove the operated parts 19a of each bolt 19, 20 from above,
Since the distance between the protrusions 21 and 22 can be adjusted by rotating 20a from above, this adjustment work is extremely simple, and productivity and maintainability are good. That is, in this load cell scale 14, since the operated part 20a of the load cell stopper 24 is also located on the support frame 6, there is no need to lift the entire load cell scale 14 to operate it, and the four corner stoppers 20a Adjustment work can be performed easily. In addition, such a stopper 2
By forming through-holes in the tray 8 above the operated parts 19a, 20a, it is also possible to adjust the stoppers 23, 24 without removing the tray 8.

[0020]

[Effects of the Invention] According to the invention as set forth in claim 1, the tray on which the object to be weighed is loaded is supported by a support frame, and the support frame fixes the load cell fixed at the movable tip to the main body housing at the base end. However, by providing a load cell stopper facing the main body housing on the support frame, even if an excessive impact load is applied to the receiver, the load cell stopper will collide with the main body housing and will not collide with the load cell. Since measurement accuracy is maintained at a high level, it has the effect of contributing to improving the durability and reliability of the load cell scale.

[0021] According to the second aspect of the invention, a load cell stopper made of a threaded body having an operated part formed at one end is screwed into the support frame from above to position the operated part on the support frame. The distance between the load cell stopper and the body housing can be easily adjusted by rotating the operated part from the support frame, contributing to improved productivity and maintainability of the load cell scale. It has the effect that it can be done.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of the present invention.

FIG. 2 is a plan view.

FIG. 3 is a longitudinal sectional side view showing a conventional example.

FIG. 4 is a plan view.

[Explanation of symbols]

6 Support frame 8 Saucer 14 Load cell scale 15, 22 Main body housing 16 Base end 17 Load cell 18 Tip 20 Screw body 20a Operated part

Claims (2)

[Claims] Claim 1: A tray on which an object to be weighed is loaded, a support frame that supports the tray, a load cell to which the support frame is fixed at a movable tip, and a main body to which the load cell is fixed at the base end. The load cell stopper is comprised of a housing and a load cell stopper provided on the support frame and facing the main body housing, and the load cell stopper comes into contact with the main body housing to regulate the amount of distortion of the load cell due to an impact load or the like. A load cell scale featuring: 2. A load cell stopper made of a threaded body having an operated portion formed at one end thereof is screwed into the support frame from above to position the operated portion on the support frame. 1. The load cell scale described in 1.