JP3746869B2 - Support device for load cell type balance - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a load cell type support device, and more particularly to a load cell type support device having a shock absorber function.
[0002]
[Prior art]
As a prior art of a load cell type balance having a shock absorber function, for example, there is a technique described in Japanese Utility Model Publication No. 61-33536.
[0003]
In the technique described in the publication, the fixed end side of the load cell is supported via a pair of upper and lower leaf springs arranged in parallel, and the Roverval mechanism is constituted by these two leaf springs. Even if the object to be measured is placed on any place of the weighing pan, the weighing pan is lowered horizontally and the four corner performance is not deteriorated.
[0004]
In addition, when an excessive impact or load is applied to the weighing pan, the leaf spring is elastically deformed so that the impact is not applied to the load cell itself, thereby preventing permanent deformation of the load cell.
[0005]
However, the load cell type support device having such a structure has the following technical problems.
[0006]
[Problems to be solved by the invention]
That is, in the support device disclosed in the above publication, since the support mechanism including the leaf spring is arranged in the extending direction along the longitudinal end portion of the load cell, the entire length becomes long. Therefore, the case had to be horizontally long.
[0007]
Further, when the total length of the load cell and the support mechanism is increased, a large moment is applied to these support portions, so that the support portions require a large rigidity, and as a result, the entire size is increased.
[0008]
In addition, when the leaf spring is oscillating for a long time, the stability of the indicated value is deteriorated, so that there is a drawback that the mechanism is complicated, for example, a presser spring must be interposed in one of the leaf springs.
[0009]
The present invention solves the above-described problems, and an object of the present invention is to provide a support device that is compact, simplified, and low-rigidity in a load cell type balance equipped with this type of shock absorber function. .
[0010]
In order to achieve the above object, the present invention provides a load cell type balance cell support device having a fixed end supported in parallel on a base plate via a support, and both ends opened, and an end portion of the load cell. A cylindrical connector that is housed inside so that the side protrudes outward from the opening, a weighing pan fixed to the upper part of the cylindrical connector, and one end formed into a U shape via the connector A pair of leaf springs, the free ends of either of the leaf springs being biased upward in advance, or the free ends of both leaf springs being upward in advance. And the connecting portion is fixed to the movable end of the load cell, and the free end side is extended to the fixed end side along the outer peripheral surface of the load cell. So that the leaf springs are parallel By being placed, an initial force to return upward is introduced into the leaf spring in accordance with the amount of upward deflection, and when a load greater than the initial force is applied, the leaf spring is It was constituted so as to be deformed downward.
According to the support device configured as described above, the pair of leaf springs having a shock absorber function has the connecting portion fixed to the movable end side of the load cell and the free end side extended to the fixed end side along the outer peripheral surface of the load cell. It is installed and fixed to the cylindrical connector.
At this time, the cylindrical connector is housed inside such that both ends are open and the end side of the load cell protrudes outward from the opening.
Accordingly, the leaf spring and connector having a shock absorber function, falls within the range of the length of the load cell becomes a state of being compressed in the longitudinal direction as compared with the prior art, it is possible to shorten the overall length, the support portion It is not necessary to increase the rigidity of the machine.
In addition, according to this configuration, the free end of at least one of the leaf springs is biased upward in advance, and the connecting portion is fixed to the movable end of the load cell, and the free end is connected to the cylinder. Since the leaf springs are arranged parallel to each other by being fixed to the tool, an initial force for returning upward is introduced into the leaf springs corresponding to the amount of upward deflection.
If such an initial force is introduced, the plate spring will not be deformed and the weighing pan will not drop downward unless a load greater than this initial force is applied, and neither the shaking nor vibration will occur in the weighing pan. . For this reason, the time until the measured value is stabilized can be shortened.
On the other hand, when a load greater than the initial force of the leaf spring is applied, the leaf spring bends and has a function of absorbing the shock.
The initial force of the leaf spring can be adjusted according to the amount of deviation. For example, if it is set to about 1 to 2 times the maximum weight of the balance, stable measurement can be performed up to the maximum weight that can be measured by the balance.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of a support device for a load cell type balance according to the present invention. The scale shown in FIG. 1 has a base plate 10, a load cell 12, a rectangular tube-shaped connector 14, a leaf spring 16, and a weighing pan 18.
[0012]
The base plate 10 has a flat plate shape, and leg portions 20 for height adjustment are screwed to the four corners. The load cell 12 has a rectangular bar shape with a concave hole penetrating through the center. The load cell 12 has a fixed end 12a at one end in the longitudinal direction, and the other end facing the fixed end 12a is a movable end 12b. Yes.
[0013]
The fixed end 12a of the load cell 12 is fixedly supported by an L-shaped support member 22 whose lower end is fixed to the base plate 10. In the supported state, the upper and lower surfaces of the load cell 12 are substantially parallel to the upper surface of the base plate 10. Yes.
[0014]
In the case of this embodiment, the connecting tool 14 has a predetermined thickness and a rectangular tube shape with both ends having a large rigidity and a load cell 12 can be inserted. Is set to a length of about 1/3 of the entire length of the load cell 12 in the longitudinal axis direction.
[0015]
When the load cell 12 is housed in the rectangular tube-shaped connector 14 having such a configuration, both end sides of the load cell 12 protrude outward from the opening of the connector 14.
[0016]
In the case of the present embodiment, the leaf spring 16 is composed of a pair of upper and lower spring portions 16a and 16b and a connecting portion 16c that connects the base end sides of the spring portions 16a and 16b. It is formed into a shape.
[0017]
Further, in the case of the present embodiment, each spring portion 16a, 16b is formed in a free state in which the respective free end sides are biased upward by substantially the same amount as shown by broken lines in FIG. ing.
[0018]
The plate spring 16 having such a configuration is fixed to the movable end 12a of the load cell 12 so that the connecting portion 16c is sandwiched between the L-shaped mounting bracket 24 and the contact plate 26. In this state, the free end sides of the spring portions 16a and 16b are fixed to the outer surface side of the connector 14, so that the spring portions 16a and 16b are parallel to each other.
[0019]
According to such an arrangement state of the leaf spring 16, each spring portion 16 a, 16 b is fixed at one end to the movable end 12 b side of the load cell 12, and the other end side is along the upper and lower surfaces of the load cell 12 toward the fixed end 12 a side. It is extended and it will be in the state fixed to the coupling tool 14 which accommodated the load cell 12 in the inside.
[0020]
When the leaf spring 16 is fixedly arranged in this manner, the connecting portion 16c is fixed to the movable end 12b of the load cell 12 in which the free ends of the spring portions 16a and 16b of the leaf spring 16 are previously biased upward. In addition, since the spring portions 16a and 16b are arranged in parallel by fixing the free end to the cylindrical connector 14, the leaf spring 16 has an upper portion corresponding to the upward deflection amount. An initial force is introduced to return.
[0021]
On the other hand, the weighing pan 18 is fixed to the upper part of the connector 14. In this embodiment, the fixed position of the weighing pan 18 is set on a substantially central axis in the longitudinal direction of the load cell 12.
[0022]
In the scale configured as described above, when a load F is applied to the weighing pan 18, the load F is applied to the load cell via the highly rigid connector 14 and the leaf spring 16 into which the initial force is introduced. 12 is transmitted to the movable end 12b, and distortion corresponding to the load F is generated in the load cell 12.
[0023]
The strain generated in the load cell 12 is converted into an electric signal by a strain gauge (not shown) attached to the load cell 12, and the magnitude of the load F is obtained by processing the electric signal.
[0024]
Now, according to the load cell type balance support device configured as described above, one end of each of the spring portions 16a and 16b of the leaf spring 16 having a shock absorber function is fixed to the movable end 12b side of the load cell 12, and the other. The end side extends along the outer peripheral surface of the load cell 12 to the fixed end side and is fixed to the cylindrical connector 14.
[0025]
At this time, since the cylindrical connector 14 is housed inside so that both ends are open and the end side of the load cell 12 protrudes outward from the opening, the leaf spring 16 having a shock absorber function and the connector 14 falls within the range of the length of the load cell 12 and is compressed in the front-rear direction as compared with the conventional one, the overall length can be shortened, and the scale can be downsized.
[0026]
In the case of the present embodiment, the leaf spring 16 is formed in a U-shape consisting of a pair of spring portions 16a, 16b and a connecting portion 16c, and the free ends of the spring portions 16a, 16b are previously upper. By fixing the connection portion 16c to the movable end 12b of the load cell 12 and the free end fixed to the cylindrical connector 14, the spring portions 16a and 16b are parallel to each other, which is biased in parallel toward the side. The initial force to return upward is introduced into the leaf spring 16 corresponding to the upward deflection amount.
[0027]
If such an initial force is introduced into the leaf spring 16, the spring portions 16a and 16b of the leaf spring 16 are not deformed and a weighing pan 18 is lowered downward unless a load greater than the initial force is applied. In addition, the weighing pan 18 is not shaken or vibrated. For this reason, the time until the measured value is stabilized can be shortened.
[0028]
On the other hand, when a load greater than the initial force of the leaf spring 16 is applied, the leaf spring 16 bends and has a function of absorbing a shock.
[0029]
In this case, the initial force of the leaf spring 16 can be adjusted by the amount of deviation. For example, if it is set to about 1 to 2 times the maximum weight of the balance, stable measurement is possible up to the maximum weight that the balance can measure. become.
[0030]
In the above embodiment, the connector 14 has a square shape, but the embodiment of the present invention is not limited to this shape, and the load cell 12 has an inner diameter that can be accommodated therein. It may be circular.
[0031]
Further, the leaf spring 16 is not limited to the U-shaped one. For example, the spring portions 16a and 16b are formed as independent plate-like members without providing the connecting portion 16c, and one end of the spring spring 16a is formed as a load cell. You may fix to the movable end 12b side of 12 with a fixing tool. Furthermore, the initial force introduced into the spring portions 16a and 16b is not necessarily introduced into both, and may be introduced into only one of the spring portions 16a and 16b.
[0032]
【The invention's effect】
As described above in each of the embodiments, the load cell scale support device according to the present invention can achieve the same function in a compressed state in the length direction, and thus has a conventional shock absorber function. Compared to a load cell type scale, it can be made smaller and less rigid.
[0033]
Moreover, according to the structure of Claim 2, since the special member for suppressing the damping vibration of a spring is not required, there exists an advantage that a structure becomes simple.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an essential part showing an embodiment of a support device for a load cell type scale according to the present invention.
FIG. 2 is a side sectional view showing the assembled state.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Base plate 12 Load cell 12a Fixed end 12b Movable end 14 Connection tool 16 Plate spring 16a, 16b Spring part 16c Connection part 18 Weighing pan

Claims (1)

A load cell having a fixed end supported in parallel on the base plate via a support;
Both ends are open, and a cylindrical connector that is housed in the load cell so that the end side of the load cell protrudes outward from the opening,
A weighing pan fixed to the upper part of the tubular connector;
A pair of leaf springs, one end of which is formed in a U shape via a connecting portion ;
A load cell balance support device comprising:
The pair of leaf springs is one in which the free end of one of the leaf springs is biased upward in advance, or the free ends of both leaf springs are biased in parallel upward in advance, The connecting portion is fixed to the movable end of the load cell, the free end side extends to the fixed end side along the outer peripheral surface of the load cell, is fixed to the cylindrical connector, and the leaf springs are parallel to each other. With this arrangement, when the initial force to return upward is introduced into the leaf spring in accordance with the amount of upward deflection, and the load greater than the initial force is applied, the leaf spring A load cell type balance support device, wherein the load cell is configured to be bent downward and deformed downward .

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