JPH0241545Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a load cell used in a weighing device.
In particular, the present invention relates to a load cell shock absorber having a structure that prevents the influence of deflection of a portion receiving the load of a weighed object.

[Conventional technology]

FIGS. 3 and 4 show how the load cell of a conventional load cell type weighing device is installed.

In a load cell type weighing device, the load of the object to be weighed is measured by electrically outputting the deformation of the load cell body (flexible body) due to the load of the object to be weighed using a strain-in gauge, so basically one load cell is used. If there is, measurement is possible. However, as the weight of the object to be weighed increases, the load cell must be considerably large in order to measure the load with one load cell, and thus a plurality of load cells are usually used for measurement. FIGS. 3 and 4 show a weighing device using a plurality of such load cells. A load cell 20 having a strain gauge (not shown) attached to a strain body is fixed to the four corners of a lower support plate 21 of the weighing device. Reference numeral 22 denotes a load receiver supported by each of these load cells 20, and is fixed to each load cell 20 so that the load receiver 22 does not easily fall off from the load cell 20. When a weighed object is placed on this load receiver 22, the load is transmitted to each load cell 20 via the load receiver 22, and the amount of electricity output from the strain gauge of each load cell is transferred to an adder (not shown).
This electrical quantity is further converted into the weight of the weighed object and displayed.

[Problem that the invention attempts to solve]

In the weighing device having the above configuration, when a large load is applied, the load receiver will bend as shown by reference numeral 22 in FIG. As long as there is no problem with the strength of the load receiver 22, the deflection of the load receiver 22 itself is not a problem. However, due to this deflection, in addition to the vertical force due to the load of the object to be weighed, complex tensile stress is generated on the load cell 20 due to the deflection of the load receiver 22, making it impossible to accurately measure the weight of the object to be weighed. There is a possibility that situations such as damage to the load cell due to excessive stress may occur.

The applicant has also proposed a mechanism in which a load cell is attached to a stretcher having moving means such as casters to measure the weight of a person placed on the stretcher. In this case, a load cell is placed between the stretcher body on which the person is directly placed and the moving frame on which the stretcher body is placed, but since both the stretcher body and the moving frame are made of pipes, It is desirable to install stress absorbing means that are compatible with the pipe structure.

[Means for solving problems]

The present invention was constructed in view of the above-mentioned problems, and by improving the connection mechanism between the load cell and the load receiver and using a ball joint structure and a spherical contact structure, The structure is configured to absorb the relative displacement between the load cell and the load receiver due to the deflection of the load receiver, so that the load cell is not subjected to unreasonable stress due to the deflection of the load receiver.

[Effect]

The connection mechanism between the load cell and the load receiver has been improved, and the connection mechanism uses both a ball joint structure and a spherical contact structure, so the relative displacement between the load cell and the load receiver is reduced by the ball. This is absorbed by the rocking of the joint mechanism and the spherical contact structure. As a result, only the stress caused by the load of the weighed object is transmitted to the load cell.
This prevents stress due to relative displacement from being transmitted to the load cell body.

〔Example〕

Embodiments of the present invention will be specifically described below with reference to the drawings.

1 and 2 show the load cell attached to the stretcher. Reference numeral 1 denotes a load cell main body which is a strain-generating body, and is fixed to a tube body 3 forming a part of the support frame of the stretcher by means of a connecting fitting 2. Arrow 4 indicates the load cell main body 1.
This is a stress absorbing mechanism attached to the upper surface of the end of the metal fitting 2 on the side facing the attachment part.

The structure of this stress absorption mechanism will be explained mainly with reference to FIG.

5 is a ball fixed to the load cell body 1 by a strong connection means such as screwing, and 6 is a ball fixed to the load cell body 1 by a strong connection means such as screwing.
This is a ball receiver that is swingably attached to the ball. 7 is a spherical contact member attached to the ball receiver 6, and its upper contact surface 7a is formed into a substantially spherical shape. Reference numeral 8 denotes a contact member receiver attached to a tube 9 constituting a part of the stretcher to be placed on the support frame. In contrast, a groove 8a having a substantially U-shaped cross section is formed. Reference numeral 11 denotes an elastic ring placed at the base of the ball 5, and is made of an elastic material such as rubber. Furthermore, 12 (see Figure 1)
is a stopper, which contacts the tube body 3 when a large load exceeding the allowable amount is applied, and prevents the load cell from buckling by transmitting a part of the load to the tube body 3. be.

For example, four load cells each having a stress absorption mechanism having the above configuration are attached to the moving frame, and a stretcher is placed directly on each load cell, or directly on the stress absorption mechanism attached to the load cell. .

Next, 10 is a stopper attached to the load cell 1, and by arranging the stopper close to the contact member receiver 8, the stretcher placed on the moving frame is prevented from shifting in the axial direction of the tube body 3 of the moving frame. . More specifically, another load cell is attached to the left side of the load cell shown in FIG. 1 so that the stress absorption mechanism is located on the left side with respect to the mounting fitting. By arranging a stopper close to the left side of the load cell, the contact member receivers are held from both sides together with the stopper shown in FIG. 1, thereby preventing the stretcher from shifting.

In the configuration shown above, when a load is applied to the tubular body 9, this load is transmitted to the load cell body 1 via the contact member receiver 8, the spherical contact member 7, the ball receiver 6, and the ball 5. At this time, if the load is relatively large, the tubular body 9 will bend toward the center of the applied load and will be displaced as indicated by the reference numeral 9a in FIG. Displacement due to this bending is absorbed by the rocking of the ball receiver 6 and the relative displacement between the spherical contact member 7 and the contact member receiver 8 that contacts the spherical contact member 7. In addition, by arranging the elastic ring 11, the tube body 9 and the contact member receiver 8 can be
When the spherical contact member 7 is removed, the spherical contact member 7 is kept upright. Also, as a matter of course, the elastic ring 11 has flexibility to the extent that it does not hinder the relative displacement of the spherical contact member 7 and the ball receiver 6 under load.

The configuration of the present invention has been explained above using as an example the state in which the load cell main body is attached to the tube body, but it is not intended to be limited to this, and the structure of the present invention is illustrated in FIG. It is natural that the present invention can be implemented in a general load cell type weighing device as shown in the figure because of its structure.

〔effect〕

As shown in detail above, the present invention has an improved connection mechanism between the load cell body and the load receiver, and has a structure that uses both a ball joint structure and a spherical contact structure. Therefore, it is possible to absorb the complex displacement between the load cell and the load receiver caused by the deflection of the load receiver, and the load cell is not subjected to unreasonable stress due to the deflection of the load receiver, improving measurement accuracy. Not only this, but also the problem of damage to the load cell due to excessive stress does not occur.

In addition, as long as the load receiver has sufficient strength to withstand the load of the object to be weighed, there is no need to worry about deflection, so there is no need to use a heavy load receiver. It is also possible to prevent the weight from decreasing.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention, and shows the arrangement of a load cell equipped with a load buffer mechanism, Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1, and Fig. 3 shows a conventional load cell type. FIG. 4 is a schematic vertical cross-sectional view of the weighing device, and is a schematic diagram of the load cell mounting portion showing the deflection state of the load receiver in the weighing device shown in FIG. 3. 1... Load cell body, 3, 9... Tube body, 4...
... stress absorption mechanism, 5 ... ball, 6 ... ball receiver, 7 ... spherical contact member, 8 ... contact member receiver,
11...Elastic ring.

Claims (1)

[Claims for Utility Model Registration] (1) In a configuration in which one or more load cells are interposed between a member on which a weighed object is placed and a member that supports the load of the weighed object placed on this member,
A ball fixed to the load cell side, a ball receiver attached to the ball so as to be able to swing,
A load cell shock absorber characterized in that a stress absorbing mechanism is constituted by a spherical contact member attached to the ball receiver, and the spherical part of the spherical contact member is configured to come into contact with the member on which the weighed object is placed. . (2) A contact member receiver having a groove having a substantially U-shaped cross section is attached to the member on which the weighed object is placed, and the U-shaped groove of the contact member is configured to contact the spherical contact member. A load cell buffer device according to claim (1) of the utility model registration claim. (3) The load cell shock absorber according to claim (1) or (2) of the utility model registration, characterized in that an elastic ring is interposed between the lower surface of the ball receiver and the upper surface of the load cell.