JPH0329713Y2 - - Google Patents

Description

[Detailed explanation of the idea] <Industrial application field> The present invention relates to electronic precision balances.

<Prior Art> Electronic balances generally have a large number of electrical components built into the balance case, and these components constantly generate heat when electricity is applied. The heat will concentrate and accumulate on the internal top surface of the balance case, but it is impossible to provide a heat dissipation port on the top surface of the balance case from the standpoint of dustproofing and waterproofing. For top-pan type electronic balances, there is a pan holder insertion slot on the top of the balance case for attaching a pan to the balance mechanism inside the balance case.
The heat accumulated inside the balance case attempts to escape in the form of an upward airflow through this only opening, the pan holder insertion slot. This upward airflow hits the bottom of the pan holder that supports the pan and is emitted to the outside of the balance, but the problem is that the collision of this airflow causes the reading on the balance to deviate to the negative side. There is.

To solve this problem, conventionally, a shielding plate has been attached in order to reduce the gap between the tray holder insertion opening and the bearing portion of the tray holder inserted into the tray holder insertion opening.

<Problem that the invention aims to solve> If the pan holder comes into contact with the balance case, etc., it will naturally not be possible to perform accurate weighing, so even if a shield plate is provided as described above, it will not necessarily be possible to measure accurately. I have to open a gap. The airflow described above will occur from this slight gap,
The reality is that conventional measures have not fundamentally solved the above problems.

The purpose of the present invention is to provide an electronic precision balance in which the above-mentioned air flow can be released to the outside without colliding with the balance holder, and the heat within the balance case can be radiated without affecting the indicated value. It is in.

<Means for Solving the Problems> The configuration of the present invention will be explained with reference to FIG. 1, which is an embodiment drawing thereof. In an electronic balance, a load support 3 connected to the balance mechanism is visible, and a plate 6 is attached to a support shaft 4 formed at the upper end of the load support 3 via a support 5. The outer diameter of the support column 3 is made larger than the outer diameter of the plate support shaft 4 by a predetermined dimension to form a stepped portion 3a. A cylindrical protrusion 7 that opens upward is formed on this stepped portion 3a.

Further, the balance case 1 supports a windshield cover 8 for covering at least the outer periphery of the pan 6, and the bottom surface of the windshield cover 8 has a space between the above-mentioned cylindrical protrusion 7 and the pan support shaft 4. A cylindrical heat dissipation guide 9 that can be fitted into the housing is made to protrude and open downward. Furthermore, a gap 10 is provided between the bottom surface of the windshield cover 8 and the top surface of the balance case 1, which allows the pan holder insertion opening 2 to communicate with the outside.
is configured so that it is formed.

<Function> The heat accumulated due to the heat generated by the electrical components in the balance case 1 flows out from the pan holder insertion opening 2 as an upward air flow, as shown by the arrow in FIG.
and escape freely to the outside world. This tray insertion slot 2
In order for the airflow in the vicinity to enter the windshield cover 8, it must pass through the gap created by the cylindrical protrusion 7 and the heat radiation guide 9, but in order to do so, the upward flow turns back and becomes downward. However, this air flow does not substantially enter into the windshield cover 8.

<Example> An example of the present invention will be described below based on the drawings.

FIG. 1 is a longitudinal cross-sectional view of the main part of the present invention.

Inside the balance case 1, an electromagnetic force generator, various other electrical components, a balance mechanism such as a beam communicating with the electromagnetic force generator, and the like are housed. A load support 3 is connected to the balance mechanism, and a pan holder insertion opening 2 is bored in the balance case 1 at a position directly above the load support 3. A dustproof ring 11 is formed along the outer periphery of the tray holder insertion opening 2 to prevent dust from entering from the outside.

A pan support shaft 4 is formed at the top of the load support column 3, and a pan support shaft 4 is attached to the pan support shaft 4. The plate holder 5 is covered with a plate 6 on which the object to be weighed is placed. The load on this pan 6 is transmitted to the balance mechanism via the load support 3, and the mass of the object to be weighed is measured from the current of the electromagnetic force generator required to generate the electromagnetic force that balances the load. has been done.

The outer diameter of the plate support shaft 4 is smaller than the outer diameter of the load support 3 by a predetermined dimension, so that the top of the load support 3 is formed with a stepped portion 3a. A cylindrical projection 7 that opens upward is formed along the outer edge of the stepped portion 3a.

On the top surface of the balance case 1, four windshield cover columns 12...12 are arranged around the pan holder insertion opening 2. A cover 8 is supported. The windshield cover 8 has a cylindrical bottom with a bottom and a funnel-shaped heat dissipation guide 9 that opens downward. It is inserted into the cylindrical gap between 4 and 4. A waterproof partition 13 is formed on the bottom surface of the windshield cover 8 and projects upward in a ring shape around the heat dissipation guide 9.
The windshield cover 8 is fitted into a ring-shaped recess formed on the back surface of the waterproof partition 13, and the attachment position of the windshield cover 8 to the balance case 1 is regulated. The windshield cover 8 and the balance case 1 are in contact only at the tips of the windshield cover columns 12...12.
A gap 10 is formed between the bottom surface of the windshield cover 8 and the balance case 1, which connects the pan holder insertion opening 2 to the outside. A removable windshield lid 14 is attached above the windshield cover 8, and when loading and unloading objects to be weighed onto the pan 6, this windshield lid 14 is removed, and during weighing, by attaching it, outside air can be removed. It is possible to prevent wind from affecting the measured value.

According to the above embodiment of the present invention, the balance case 1
Heat from various electrical components housed within the
As shown by the arrow in the figure, the air flows upwardly, passes out of the balance case 1 through the pan holder insertion opening 2, and is freely discharged to the outside through the gap 10. here,
The inside of the balance case 1 communicates with the inside of the windshield cover 8 through a gap between the cylindrical projection 7 at the upper end of the load support 3 and the heat radiation guide 9. In order to enter into the windshield cover 8, the airflow needs to bend in the opposite direction from upward to downward, and this airflow does not substantially reach the inside of the windshield cover 8.

As shown in FIG. 2, a heat dissipation guide 9 is provided on the bottom of the windshield cover 8 closer to the center than the waterproof partition 13.
If the dustproof partition 15 is provided by using the dustproof partition 15, prevention of foreign matter from entering the balance case 1 can be strengthened.

In addition, FIG. 3 shows a windshield case 2 having a door 21.
An example in which the present invention is applied to a high-sensitivity electronic balance equipped with a weighing chamber 22 separated from the outside air by a zero is shown. In this case, a windshield cover 8' similar to that shown in FIG. As a result, the air flow from the balance case 1 enters the weighing chamber 22, and the heat inside the balance case 1 is radiated.
The airflow does not collide with the pan 6 and the pan holder 5.

Furthermore, in the electronic balance equipped with the high-sensitivity weighing chamber 22 as described above, as shown in FIG.
The bottom surface of the windshield case 20' is supported by a column 32 projecting from the top surface of the balance case 1 to form a gap 10' that communicates with the outside. By facing the load support 3 similar to the guide 9, the balance case 1
The upward air flow from the air can be guided to the outside through the gap 10' without entering the capacity chamber 22.

<Effects> As explained above, according to the present invention, the heat generated in the balance case 1 is released from the pan holder insertion opening 2 as an air stream that rises outward. The airflow does not collide with the pan holder 5 and the pan 6 and affect the measured value, thereby improving the measurement accuracy. Further, unlike in the conventional case, the opening area of the tray holder insertion port is not reduced by a shielding plate or the like, so the resistance of the heat radiation path is reduced and the heat radiation effect is increased.

[Brief explanation of the drawing]

FIG. 1 is a central vertical sectional view of a main part of an embodiment of the present invention, and FIGS. 2, 3, and 4 are sectional views of main parts of other embodiments of the present invention. 1... Balance case, 2... Pan holder insertion slot, 3
...Load support column, 4...Dish support shaft, 5...Dish support,
6...Dish, 7...Protrusion, 8...Windshield cover, 9...
...Heat radiation guide, 10...Gap, 12...Windshield cover support.

Claims (1)

[Scope of utility model registration request] The load column connected to the balance mechanism can be seen through the pan holder insertion slot drilled on the top of the balance case, and the plate is attached to the pan holder shaft formed at the upper end of the load column via the pan holder. In the electronic balance, the outer diameter of the load support column is made larger than the outer diameter of the pan support shaft by a predetermined dimension to form a stepped portion, and a cylindrical protrusion that opens upward is formed in the stepped portion. Additionally, a cylindrical heat dissipation guide that can be fitted into the gap between the cylindrical protrusion and the pan support shaft is provided on the bottom surface of the windshield cover that is supported by the balance case and covers at least the outer periphery of the pan. The electronic device is characterized in that the electronic device is configured to protrude and open downward, and to form a gap between the bottom surface of the windshield cover and the top surface of the balance case, which allows the pan holder insertion opening to communicate with the outside. Precision balance.