JP2006071391A - Waterproofing type electronic balance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrical balance of a waterproof construction capable of preventing a measured value from being influenced by a change in instrument inside pressure resulting from a change in load and a change in temperature, a change in outside air pressure, etc., at measurement. <P>SOLUTION: An instrument inside pressure adjusting diaphragm is provided for adjusting the change in the instrument inside pressure resulting from the change in load, the change in temperature, and a change in air pressure at measurement. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a waterproof structure for solving a problem of a change in internal pressure caused by completely sealing the inside of a scale in a waterproof electronic balance.

In recent years, hygiene management has been thorough in the food industry and the like, and it is necessary to consider hygiene even when it comes to inspection equipment as well as manufacturing equipment used in food factories.
Electric scales used for weighing also need to be thoroughly cleaned after the start of work because food comes into direct contact with the weighing.

Conventionally, various techniques have been introduced for the waterproof structure of the balance. For example, Non-Patent Document 1 includes a method in which a bellows is provided in a portion where bending occurs and the internal pressure is made constant with respect to a change in bending due to a load, or an air vent hole is provided for the purpose of keeping the internal pressure change constant. is there. However, if an air vent hole or the like is provided, a completely waterproof structure cannot be obtained. For example, a structure in which water does not enter even if submerged in water (for example, IP67) cannot be cleared. Incidentally, for example, IP65 is a structure in which water does not enter even if the balance is directly washed with water. Further, as a waterproof scale, there is Patent Document 2 as a blocking technique having a structure in which an electronic circuit board or the like is not easily exposed to moisture.

Therefore, when the balance is sealed, the internal pressure directly loads the detector due to weighing, temperature change, and pressure change, and accurate weighing is not possible. For example, an object to be weighed is placed on a weighing pan. The internal pressure rises due to the deflection of the load cell and the volume change due to the switch operation. In addition, when the temperature changes from low temperature to high temperature or when the atmospheric pressure becomes lower than the initial state (during assembly), the internal pressure in the vessel increases. Due to these factors, a load is applied in the direction of raising the detector, and accurate measurement is difficult in a completely sealed structure.

Japanese Utility Model Publication No. 2-5039

JP 2003-322556 A

However, in these prior arts, if they are immersed in water and washed, water enters the vessel through the air vent hole and the scale breaks down. There was a problem.

If the air vent hole is removed and the cylinder is completely sealed, it will not be possible to follow changes in pressure due to deflection during measurement, changes in pressure due to changes in outside air temperature, and changes in pressure due to changes in atmospheric pressure. There was a problem that it was impossible to measure accurately.

In addition, if the area of the air vent hole is reduced in order to improve waterproofness, there is a problem that the response of the scale is lowered.

In the invention according to claim 1, a load sensor is provided in the main body case, a weighing pan is provided at a movable end of the load sensor, and a diaphragm is provided between the weighing pan or a receiving member of the weighing pan and the main body case. In the waterproof electronic balance, a pressure adjusting diaphragm having a spring constant different from that of the diaphragm is further provided in order to adjust a differential pressure between the pressure inside the case and the pressure outside the case separately from the diaphragm.

In the invention according to claim 2, a load sensor is provided in the main body case, a weighing pan is provided at a movable end of the load sensor, and a diaphragm is provided between the weighing pan or a receiving member of the weighing pan and the main body case. In the waterproof electronic balance, in addition to the diaphragm, a pressure adjusting bellows pump having a spring constant different from that of the diaphragm is further provided to adjust a differential pressure between the pressure inside the case and the pressure outside the case. .

According to a third aspect of the present invention, the pressure adjusting diaphragm is provided below the main body case.

The waterproof electronic balance according to claim 2, wherein the pressure adjusting bellows pump is provided on a side surface of the main body case.

The invention according to claim 5 is the waterproof electronic balance according to claim 1, wherein a protective cover is provided on the pressure adjusting diaphragm.

A sixth aspect of the present invention is the waterproof electronic balance according to the second aspect, wherein a protective cover is provided on the pressure adjusting bellows pump.

As described above, according to the present invention, even if the inside of the vessel is completely sealed, the pressure change in the vessel due to the deflection of the load cell, the pressure change in the vessel due to the temperature change of the outside air, and further the change in atmospheric pressure and the pressure in the vessel. It is possible to automatically adjust the differential pressure, and accurate weighing is possible.

Moreover, it becomes possible to wash | clean a balance by immersing in water, and there exists an effect that the improvement of a cleaning property and the improvement of a hygiene aspect can be aimed at.

Embodiments of the present invention will be described with reference to the attached drawings. FIG. 1 is a diagram showing a first embodiment, wherein 1 is a diaphragm for adjusting the pressure inside the chamber, and this member instantaneously adjusts the deflection of the load cell due to weighing and the pressure change in the chamber due to the operation of the switch, Enables accurate weighing with high responsiveness. The diaphragm for adjusting the internal pressure of the chamber is preferably one having a much smaller spring constant than the diaphragm of 2, and is attached between the inner cover of 3 and the tray receiver B of 4, and seals the movable part by weighing. It is possible and the diaphragm is mounted downwards and hygienic measures are taken. Reference numeral 6 denotes a load cell. In this structure, the high water resistance of the load cell itself is unnecessary. In order to prevent the internal pressure adjusting diaphragm from being deformed due to a sudden change in internal pressure, and being damaged by protrusions from the outside, 7 is an upper internal pressure adjusting diaphragm protective cover. , 8 is provided with a diaphragm protective cover for adjusting the pressure in the lower unit. The outer cover 9 may be made of, for example, stainless steel, and the end of 10 is processed by an inner curl shape on the entire circumference, and the curl shape is caught by 11 claws integrally formed on the base. Yes, the outer cover can be removed with one touch.

FIG. 2 is a diagram showing a first embodiment. In FIG. 2, reference numeral 21 denotes a pump with a bellows for adjusting the internal pressure, which is characterized by having a larger capacity that can be adjusted than the diaphragm 1 for adjusting the internal pressure described in the first embodiment. The pump with bellows has a structure that can be applied to a scale with low accuracy and a large sensitivity (scale) because the resistance of the member itself is increased as compared with the diaphragm type. In addition, the pump 21 with bellows for adjusting the internal pressure is provided on the inner surface of the outer cover 9 and is attached so as to prevent deformation and breakage due to external factors.

FIG. 3 shows a third embodiment. Reference numeral 1 denotes a diaphragm for adjusting the internal pressure. As in the first embodiment, the internal and external pressure adjusting diaphragm protective covers 7 and 8 are prevented in order to prevent deformation of the internal pressure adjusting frame due to a sudden change in internal pressure and damage due to protrusions from the outside. Is provided. Reference numeral 2 denotes a diaphragm, which is attached between the load cell attachment plate 14 and the base 30 and has a sealed structure of movable parts by measurement.

FIG. 4 shows the fourth embodiment. As in the first embodiment, 61 is a diaphragm for adjusting the internal pressure, and 62 is a diaphragm. The chamber pressure adjusting diaphragm 61 and the diaphragm 62 are integrated, and the number of parts can be reduced. In order to prevent internal pressure adjustment diaphragms 61 and 8 from being deformed by internal pressure adjustment diaphragms due to sudden changes in internal pressure and damage from external projections, protection of internal pressure adjustment diaphragms 7 and 8 A cover is provided. The diaphragm portion 61 is attached between the bases of the twelve platform covers 64 and 65, and the movable portion is sealed by measurement.
In addition, because the third diaphragm is mounted upward, water can accumulate in the diaphragm and the growth of miscellaneous bacteria due to the residue of the object to be weighed can be considered. It has been.

(A) is a longitudinal cross-sectional view showing a diaphragm mounting structure for adjusting the internal pressure of a waterproof electronic balance in the first embodiment of the present invention. (B) is a cross-sectional view showing a diaphragm mounting structure for adjusting the internal pressure of a waterproof electronic balance in the first embodiment of the present invention. It is a pump attachment structure figure of the internal pressure adjustment of the waterproof electronic balance which shows 2nd Example of this invention. It is a diaphragm attachment structural drawing of the pressure adjustment in the container of the waterproof electronic balance which shows 3rd Example of this invention. It is a diaphragm attachment structure figure with the diaphragm for the internal pressure adjustment of the waterproof type electronic balance which shows 4th Example of this invention.

Explanation of symbols

1 Internal pressure adjustment fram 2 Diaphragm 3 Inner cover 4 Dish tray B
6 Load cell 7 Diaphragm protection cover for upper internal pressure adjustment 8 Diaphragm protection cover for lower internal pressure adjustment 9 Outer cover 10 Outer cover inner curl 11 Outer cover fixing claw 12 Mounting plate 13 Dish tray A
14 Load cell mounting plate 30 Base 61 Diaphragm with diaphragm for adjusting internal pressure (Fram part for adjusting internal pressure)
62 Diaphragm with diaphragm for adjusting internal pressure (diaphragm part)
64 base cover 65 base

Claims (6)

In a waterproof electronic balance provided with a load sensor in a main body case, provided with a weighing pan at a movable end of the load sensor, and provided with a diaphragm between the weighing pan or a receiving member of the weighing pan and the main body case, A waterproof electronic balance further comprising a pressure adjusting diaphragm having a spring constant different from that of the diaphragm in order to adjust a differential pressure between the pressure inside the case and the pressure outside the case separately from the diaphragm. In a waterproof electronic balance provided with a load sensor in a main body case, provided with a weighing pan at a movable end of the load sensor, and provided with a diaphragm between the weighing pan or a receiving member of the weighing pan and the main body case, A waterproof electronic balance further comprising a pressure adjusting bellows type pump having a spring constant different from that of the diaphragm in order to adjust a differential pressure between the pressure inside the case and the pressure outside the case separately from the diaphragm. The waterproof electronic balance according to claim 1, wherein the pressure adjusting diaphragm is provided at a lower portion of the main body case. The waterproof electronic balance according to claim 2, wherein the pressure adjusting bellows pump is provided on a side surface of the main body case. The waterproof electronic balance according to claim 1, wherein a protective cover is provided on the pressure adjusting diaphragm. The waterproof electronic balance according to claim 2, wherein a protective cover is provided on the pressure-adjusting bellows pump.

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