JPS603524A - Weight measuring device - Google Patents

Abstract

PURPOSE:To attenuate and stabilize a load vibration by a natural frequency of a load cell as quickly as possible and detect the weight precisely by connecting the load cell to a frame through a vibration damper provided on the other side. CONSTITUTION:When a combined measuring device is operated, and an object to be measured is thrown into a measuring hopper, a load cell 7 supported in a cantilever form against a frame 2 by its throw-in energy is vibrated by its natural frequency first, and its detecting signal is inputted to a micro-computer. During this time, a base vibration is transferred and inputted unavoidably to the load cell 7 and a dummy load cell 7' through the base from the frame 2. Accordingly, a disturbance vibrating signal by throwing in the object to be measured from the measuring hopper, a base vibrating signal, and a weight signal of the object to be measured are joined and inputted in advance to a detecting signal detected and inputted by the load cell 7.

Description

[Detailed Description of the Invention] Technological Classification/Field> The disclosed technology belongs to the technical field of improving the weighing accuracy of load cell scales for weighing, which are used to hang granular products during the distribution process. .

<Explanation of the gist> The invention of this application is provided with a scale base on one side of a load cell in an Imif weight station on which objects to be weighed, such as a weighing pan or a weighing hopper, are placed and stored via a support. The invention also relates to a weighing device in which the other side of the load cell is directly or indirectly linked to another support for the frame via an elastic body that absorbs vibrations, and in particular, the other side of the load cell is basically connected to the elastic body. The load cell is attached to the frame with good damping characteristics through a vibration damper, and furthermore, the load cell is damped and vibrates downward parallel to -, and the load cell has the same natural frequency. This invention relates to a weighing device that is equipped with a dummy load cell having a dummy load cell and converts a vibration signal from the base from a detection signal from the load cell to accurately detect weight.

<Prior art> As is well known, in all industrial fields, the weight of various parts, etc. is measured.For example, in the manufacturing field, the weight of each part is measured by an indefinite amountffl, and in the distribution sector, the above-mentioned indefinite amount is measured. In addition, if the weight of many products is negative from the set weight, tTJ: The quantity of the product is quantitatively weighed to the minimum overhang.

Therefore, in recent years, it has become essential to be at least accurate and prompt in any type of weight measurement, so measuring the weight of an article is based on the condition of the article and the method. Although it depends on the relative condition of the device, since the weighing device is an industrial product, it is possible to some extent to select a weighing device with the necessary marks for weighing, but the method of loading the goods is , for example, when J
: So, it is extremely irregular, and it is impossible to understand it as a state of law and use it as an object of measurement.

Oh,, 5ka8, Z +7) 1ゎ. kaa'r *i
l-ifi #* tM i, :Tie 1 was generally ignored to some extent and compensated for by correction on the measuring device side.

For example, in the measuring device disclosed in Japanese Utility Model Application Publication No. 54-171368, as shown in FIG. A holding plate spring 4 is interposed between the plate springs 4 and a support bracket 5 is provided at the tip of the plate spring 4. A cushioning rubber 6 is interposed between the brackets 5 and the load cell 7 to be able to pivot in the horizontal direction. Another support member 8 is rotatably provided at the tip of the load cell 7 via another cushioning rubber member 6, and a receiving booklet 9 as a barb is provided on the upper part of the support member 8.

Therefore, in the prior art of this type, as shown in the Publication No. 2, permanent distortion occurs in the load cell 7 when the receiver is subjected to an impact from an object to be weighed that is thrown into the curve 9, etc. In order to avoid this, the rubber 6 absorbs the lateral impact and causes the load to rotate laterally, and the leaf spring 3.3 absorbs the vertical impact. It is as it should be.

4- Then, the other leaf spring 4 presses the leaf spring 3 to release the leaf spring 3.
Although it is said that it suppresses the vibration of
It is clear that it has only one function.

This is because the leaf spring 4 generates frictional resistance due to pressure and does not have a damping function based on elastic resistance.

Therefore, we created an experimental model for the conventional weighing device as shown in Fig. 1, and measured it with the load removed instantaneously. If the amplitude R is taken on the axis, the attenuation characteristic is extremely poor and does not attenuate easily. Therefore, the weight measurement signal by the load cell 7 does not indicate accurate measurement at a specific time after loading the object to be weighed, and the The disadvantage is that the characteristics over time leading to measurement stability are poor.

It can also be seen in FIG. 2 that the conventional weighing device 1 has virtually no damping effect, and only a slow vE mechanism.

To deal with this, in the conventional system, it is unavoidable to use the amplifier circuit (filter) to lower the sensitivity for measurement, and as a result, as shown in Figure 3, high frequency signals are filtered out. This was measured after the condition was stabilized for a certain period of time.

However, as shown in Figure 3, there are actually minute vibrations propagated from the base (after low frequencies that cannot be removed by the filter), making it difficult to measure with high precision. .

By the way, the GLL U-Line that performs such precise measurements has the installation base where the measuring device is installed, the ground, building, trestle, other lines related to the base, or
There is a complex or loose base vibration that occurs in the line, etc., and this is transmitted to the load cell, and the base vibration coming from this base is applied to the load cell, and the load cell also stably detects the weight. There was a problem that I couldn't do it.

As shown in Figure 4, load cells in weighing devices normally experience disturbance vibrations when an object to be weighed is introduced or loaded, but this is quickly attenuated, and the various base motions coming from the base are Although it is desirable to stably detect the correct weight as soon as possible after removal, the above-mentioned conventional four-hanging device 1 cannot perform the above-mentioned operation. From this point of view, the conventional weighing device 1 has a fatal flaw in that it cannot eliminate the base vibration as well as damp it, and only has a buffering function to avoid permanent distortion. The disadvantage was that accurate measurements could not be performed.

In addition, in order to quickly dampen the disturbance vibration of the load cell, measures such as installing an additional dashpot to absorb the vibration energy with viscous resistance have been considered, but the The transducer, which has a mechanism that detects the load by making extremely small displacements and deforming the strain-generating body, maintains its measuring accuracy and sensitivity while maintaining the external dash, 1<t1. ．． W,) Care 7□□, Machining, Gakka, Acca□ In order to produce l, the displacement of the load cell, displacement speed, and absorption 7- Design and manufacture of a damper that matches the absorbed energy is rotation, and it is very realistic. The problem was that it was difficult to install.

<Object of the Invention> The object of the invention of this application is to provide a measuring device which does not have the damping function of the measuring device based on the above-mentioned prior art, nor does it have the base vibration removing function, but only has a buffering function. The problem is a technical issue to be solved, and the load cell has a damping function that reliably suppresses vibration without reducing sensitivity, so that stable weight measurement can be performed as soon as possible, and Or, by reliably eliminating base vibrations to the weighing device, it is possible to reliably perform high-precision M quantity measurement from that point of view, which is beneficial to all industrial fields. Our goal is to provide an excellent weighing device.

<Structure of the Invention> The structure of the invention of this application, which is based on the above-mentioned claims in accordance with the above-mentioned object, is to solve the above-mentioned problems by introducing the object to be weighed into the weighing body of the weighing device. When a is loaded, its weight is transmitted to the load cell through the support on the load side and its detection pattern is measured.Meanwhile, the load cell begins to vibrate at its natural frequency due to the impact of the load, and the load cell's Since it is connected to the frame via a vibration damper installed on the other side, external vibrations are damped by the internal friction of the vibration damper, and the damping is quickly stabilized. Furthermore, a dummy load cell is provided in a cantilever type at the tip of the vibration damper, and a dummy mass is provided on the load side of the dummy load cell using the frame holes of both the load cell and the dummy load cell. The same base vibration as that of the load cell is propagated, and the detected signal of the base vibration is removed from the detection signal of the object to be measured detected from the load cell through the base and frame to the dummy load cell. This is a technical measure that enables quick weighing of objects to be weighed.

<Structure of the Invention> Next, embodiments of the invention of this application will be described below based on the drawings from FIG. 5 onwards. Note that the same parts as in FIG. 1 will be explained using the same reference numerals.

In the embodiment shown in FIGS. 5 to 8 (FIGS. 5 and 7 are side views in opposite directions), 1' is a measuring device that constitutes the gist of the invention of this application, The illustrated embodiment is used in the distribution department as a weight detector of a combination weighing device, for example,
It is used to measure the weight of granular products such as snack products to the minimum excess amount so as not to become negative in order to pack the weighed items at a predetermined weight. A support member 8' that engages the Wl side hopper is fixed to the load side of the tip of a well-known load cell 7, and the extension side of the load cell 7 is fixed to a predetermined support member 5'.

The support body 5' is attached in a cantilever manner to the frame 2 which is attached in a predetermined manner to a frame forming the skeleton of the silk combining and weighing device (not shown). Vibration damping rubber as a vibration damper with excellent internal friction 12.1
2... are provided above and below the center of 21171+, and the frame 2 is connected to the support body 5' through a pair of left and right brackets 10 and 11 that are fixed opposite each other, and the load cell 7 is installed in a cantilever type. J-ru so that it can be measured.

In addition, for the upper and lower surfaces of the brackets 1 to 10.11,
The leaf springs 3' and 3' are bolted and fixed, so that the load cell 7 can be restrained and displaced relative to the frame 2 as a kind of parallel link.

Further, as shown in FIG. 6, a dummy load cell 7' is attached to the front side of the support 5' by a screw 14 in a cantilever manner, and the load cell 7 and the dummy load cell 7' are attached to the tip of the dummy load cell 7' near the front surface 1 side of the support body 5'. The support plate 13 is installed so that the support plate 13 is present in the space between the load cells 7', so that there is a minute clearance in the space that does not interfere with the inner surfaces of the opposing load cells 7 and dummy load cells 7'. It is formed as follows.

The load cell 7 and the dummy 2-
Dummy ma = 11 facing the frame hole 16 of the load self'
- the base 15 is fitted in a replaceable manner;

The dummy mass 15 is connected to the load cell 7 through a support 8', and the load cell 7 is engaged with the load cell 7 through a support member 8', and the same natural vibration as that formed in the load barrel 7 due to the vibrating weight such as the empty weight of the weighing hopper is applied to the load cell 7. Therefore, if the weighing hopper for the load cell 7 is replaced with another type and the oscillating weight changes, the dummy mass 1 is changed accordingly.
5 is also made replaceable, and the natural frequencies of the load cell 7 and the dummy load cell 7' are always made the same, so that the base vibration Wj
The same signal can be output for +.

Reference numerals 17 and 17 indicate well-known strain gauges attached to the load cell 7 and the dummy load cell 7', which are electrically connected to the control circuit of the micro combi coater (not shown), as in the conventional embodiment. Input the detected weight signal in the above fft M hopper,
On the other hand, if the detected weight signal of the dummy mass is inputted from the dummy load cell 7', then =12- Since both signals include output signals due to various base vibrations from the base (not shown) transmitted from the frame 2, a constant By subtracting the weight signal of the dummy load cell 7' from the weight signal detected by the load cell 7 by an arithmetic circuit, a variable element due to base vibration is removed and the net weight can be easily measured.

<Embodiment - Effect> In the above-described configuration, when the combination weighing device is activated and an object to be weighed is put into the weighing hopper, the load cell 7 supported in a cantilever manner with respect to the frame 2 is first moved by the input energy. It vibrates at a natural frequency, and its detection signal is input to the micro combi coater (not shown) as described above.

During this time, base vibration is inevitably transmitted and input from the frame 2 to the load cell 7 and the dummy load cell 7' through the base.

Therefore, the detection signal detected and input by the load cell 7 includes the disturbance vibration signal caused by the loading of the object from the weighing hopper, the base vibration signal, and the weight information of the object to be weighed. This means that it has been done.

Of course, the dummy load cell 7' has a dummy mass 15, which is equal to the vibration weight of the load cell 7 excluding the object to be measured, and therefore vibrates at the same natural frequency, so that its detected disturbance signal and impact areぢ、The dummy load is Lua′
What it is detecting is inputting the output signal itself from the base vibration to the microcomputer.

Therefore, the microcomputer always performs calculations to remove the output signal due to the base vibration detected by the dummy load cell 7' from the detection signal of the load cell 7.

Thus, the load cell 7 has a support 5 on one side thereof.
', the vibration damping rubber 12 is integrated with the bracket 10 and is supported in a cantilever manner by the frame 2 integrated with the bracket 11 via the damping rubber 12, 12, etc., which is integrated with the bracket 10. As shown in Fig. 4, the vibration is rapidly attenuated by the damping function via the damping function due to the internal friction caused by the deformation of . Since the fluctuations caused by this are removed, the detection signal quickly stabilizes (in fact, after the cancellation operation).

Then, under predetermined calculation control, the weighing hopper is opened and the objects to be weighed are transferred to the next packaging process.

Then, the load cell 7 and the dummy load cell 7' perform damped vibration due to internal friction caused by the deformation of the damping rubber 12.12, but in this case, the frame 2 and the bracket 1
Since it is not preferable that the plate springs 3' and 3' be displaced non-parallel to the bracket 10 and 11, the plate springs 3' and 3' attached to the upper and lower surfaces of the bracket 10 and 11 by screws, etc. ' damped vibration is performed in parallel displacement with respect to the frame.

Incidentally, the damped vibration of the dummy load cell 7' of the loadrel 7 described in 4- is carried out by internal friction caused by the deformation of the damping rubber 12, 12..., and the parallelism (i'7 is maintained!) is substantially maintained. hand
1. The load cell 70 is designed to have no effect on weighing.15
- In the meter mode, the bracket 10.1 is attached as shown in Figure 9.
Between 1 and 2 Iζ are 4 vibration damping rubbers 12.12...
It is also possible to only connect the leaf springs 3' and 3' without connecting the plate springs 3' and 3', or to connect the plate springs 3' only to the two sides of the bracket 10 and 11. You can also do it.

By the way, with weighing equipment, there are cases where it is necessary to precisely measure chemicals, weights, and extremely small units of weight such as radioactive materials, but on the other hand, when handling such important materials, for example, For precision weighing such as weight inspection, the surface plate and pedestal supporting the weighing device have an earthquake-proof structure, and the building's concrete thickness and many suspended reinforcing bars are isolated from the surrounding ground from ground vibrations by grooves, and the entire structure is isolated from ground vibration. may have a rigid structure that hardly vibrates, but when installing a weighing device in such a building, it is necessary to simply provide a vibration damper for the load cell 7 without providing a dummy load cell 7' as in the example above. Therefore, in such a case, as shown in FIG. 10, remove the dummy load cell 7' from the embodiment shown in FIG. All you have to do is set it up.

Therefore, in this embodiment, leaf springs 3+13' are installed vertically between the LC brackets 1 to 11 provided on the support body 5' and the brackets 1 to 10 provided on the frame 2, as shown in FIG. By connecting a plurality of damping rubbers 12, 12... and having a damping function due to the internal friction of the damping rubbers 12, 12..., it is possible to quickly and stably detect small amounts. I can do it J: I will do it.

Furthermore, if the vibration displacement of the load cell 7 is kept parallel to the frame 2, the leaf springs 3', 3' may be omitted as shown in FIG. 11, or they may be provided only on the upper side. Also good.

As shown in the series, the invention of this application has two degrees of freedom in which the load cell is supported via a vibration damper with respect to the fI norm, whereas the conventional one degree of freedom was measured based on the natural vibration of the load cell. By using a degree-of-freedom system, vibration damping is achieved based on the internal friction of the vibration damper, which damps the transmission characteristics of the natural frequency of the system in the measuring section, thereby suppressing vibration when an object to be measured is loaded. The basic idea is to promote the stabilization period as quickly as possible.

As a vibration damper, it is basic to use a dashpot that uses viscous resistance, such as an oil damper, but as mentioned above, oil dampers are difficult to design and manufacture.
Using damping rubber that has internal friction equivalent to this viscous resistance simplifies design and manufacturing, and reduces costs.

The manner in which the vibration damper is provided separately from the displacement of the load cell is not limited to the above-mentioned embodiments. For example, as shown in FIG. It may be placed on the lower side, or it may be placed on the lower side with a plurality of vibration dampers as shown in the embodiment shown in Fig. 13. As in the embodiment shown in FIG. 14, a plurality of vibration dampers and a coil spring 18 may be provided on the lower side.

Furthermore, the frame 2 that directly supports the load cell 7 in a cantilever type is attached to the device frame on both sides by vibration dampers 1.
2 may be supported as shown in FIG. 15, or the side support may be supported by a plurality of vibration dampers 12 on each side as in the embodiment shown in FIG. Also good.

It goes without saying that the embodiments of the invention of this application are not limited to the above-mentioned embodiments, and various embodiments can be adopted.

The installation of the invention of this application is not only for the measuring pan-type unstable weighing scale, but also for the silk combination weighing of continuous quantitative weighing in the distribution process, which has been variously proposed in the applicant's earlier patent invention. It can also be used in equipment, and is applicable to all types of weighing equipment.

<Effects of the Invention> According to the invention of this application, basically, when measuring weight using a load cell, when an object to be measured is introduced or loaded, there is no need to apply a large impact that permanently deforms the device itself. Apart from this, the vibration damper effectively damps the unavoidable vibration A, and the load vibration due to the natural frequency of the load cell is attenuated and stabilized as soon as possible, allowing accurate weight detection. Excellent effects can be achieved.

In addition, in a weight scale device equipped with a dummy load cell, base vibrations coming from the ground etc. from the base where it is installed are transmitted from the frame, and in addition to the above-mentioned damped vibrations, the output signal due to the base vibration is included in the detected photographic signal. Since the dummy load cell can eliminate contamination and inaccurate measurement, an excellent effect is achieved in that accurate weight detection is possible.

Since the above-mentioned vibration damper is interposed between the load cell and the frame when the load cell is mounted in a cantilever manner, the inside of the vibration damper is By adding one more degree of freedom, that is, the inclination due to friction, a two-degree-of-freedom system is created, which provides an excellent effect in that damped vibrations are quickly suppressed and metering can be performed accurately.

In addition, by providing a parallel link on the outside of the 20-vibration damper provided between the frame and the load cell, when the load cell performs damped vibration by the vibration damper, the load cell is parallel to the frame. The effect of this displacement is that the damped vibration is stably produced without causing new secondary disturbances.

In addition, in the case of a dummy load cell, a dummy mass is attached to the tip of the dummy mass so that the natural frequency is the same as the natural frequency of the load cell, and the same signal can be output in response to the base vibration. The vibration is detected by the dummy load cell and calculated by a microcomputer, etc., and the variable element due to the base vibration is canceled from the detection signal of the load cell, making it possible to accurately measure the vehicle weight based on only the loaded load. The effect is produced.

In addition, since a load cell normally has a frame hole, the dummy mass attached to the dummy load cell can also be set there using the frame holes of both, which is an advantage in that the weighing device can be made more compact. effect is produced.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view of a weighing device based on the prior art;
Figure 2 is a damped vibration graph of the same <81 suspension device based on the prior art, Figure 3 is a damped vibration graph of a filter diaphragm based on the prior art, and Figure 4 is a graph of the damped vibration of the present invention that cancels the base vibration. Damped vibration graph of measuring device, 5th
The following figures are detailed explanatory drawings of the invention of this application, in which FIG. 5 is a partial cross-sectional side view of one embodiment, FIG. 6 is a top view of the same,
FIG. 7 is a side view of the other embodiment, FIG. 8 is a perspective view of the same, FIG. 9 is a perspective view of another embodiment, FIG. 10 is a perspective view of another embodiment, and FIG.
1 is a perspective view of yet another embodiment, FIGS. 12 to 14 are schematic side views of still another embodiment, and FIGS. 15 and 16 are schematic top views of still another embodiment. 8'...Support, 7...Load cell, 2...Frame, 5'...Other supports, 1', 11.1',
1"...Measuring device, 12...Vibration damper, 3', 3'...Parallel link, 7'...Dummy load cell, 15...Dummy mass, 16...Frame hole applicant stock Company Ishida Koki Seisakusho

Claims (7)

[Claims] (1) In a weighing device in which a load cell having a support for a weighing body on one side is linked to another support for a frame via an elastic body on the other side, the other side of the load cell is connected via a vibration damper. A weighing device characterized by being linked to the frame. (2) In a weighing device in which a load cell having a support for a weighing body on one side is connected to a vibration damping support for a frame via an elastic body on the other side, the load cell has a vibration damper on the other side. A weighing device characterized in that the weighing device is linked to the frame via a parallel link, and the vibration damper is moved up and down and linked to the frame by a parallel link. (3) The measuring device according to claim 1 or 2, wherein the vibration damper E is a vibration damper. (4) A patented measuring device characterized in that the parallel link is a leaf spring. (5) In a device in which a load cell in which a support body for a weighing body is shifted to one side and the other side is linked to one support body for controlling a frame through an elastic body, the other side of the load cell is vibration suppressed. A dummy load cell, which is connected to the frame via a damper and which is different from the load cell, is attached to the support of the main body, and has a dummy mass and a dummy mass, and has the same natural frequency. A quantification device characterized by: (6) The dummy mass is provided in both frame holes of the load cell and another load cell via supports. (7) The dummy mass according to claim 5 or 6, wherein the dummy mass is arranged in a dummy load sensor so as to be replaceable.