JPS5938139B2 - Sealed metal lid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a punch-sealed metal lid made of elastic metal, such as a can lid or a bottle lid, which immediately responds to changes in pressure inside the container to the outside.

Even in this type of sealed metal lid, there is a demand for thinner lid plates in response to the demands of the era of resource saving and material reduction. However, in sealed containers such as coffee drinks that require retort sterilization, the positive pressure is 2 to 3 9/C during retort sterilization.
After cooling, negative vacuum internal pressure is applied.

On the other hand, with the spread of automatic percussion instruments that determine whether the internal pressure of a sealed container is good or bad based on the sound wave signal generated in response to the application of an electromagnetic shock impulse to a sealed metal lid, acoustically defective containers can be detected stably and accurately. These are also being demanded. The automatic punching tester excludes sealed containers with values outside the range of preset characteristic values, and the vertical axis is the automatic punching tester characteristic value, and the horizontal axis is the degree of vacuum inside the container. 1st
Referring to the graph shown in the figure, the accuracy of acoustically defective container detection is better when the slope of the characteristic curve is as large as possible, such as a, rather than b.

If the sealed metal lid flips, the characteristic curve will have a maximum or minimum value as shown in c, and if the deformation behavior of the sealed metal lid becomes complicated, the variation in vacuum internal pressure will increase as shown in d, and the acoustic Not suitable for detecting defective containers. Thus, in order to stably detect acoustically defective containers with an automatic percussion detector, the following conditions must be met for the sealed metal lid: 1. The sealed metal lid must not exhibit complex deformation behavior of secondary or higher order due to vacuum internal pressure. , 2. The sealed metal lid does not flip at a certain vacuum value, and 3. The degree of deformation of the sealed metal lid is large in response to a slight pressure change.

By the way, in the conventional sealed metal lid that forms a flat countersink center panel (hereinafter referred to as center panel) as shown in Figures 2 and 3 and wraps it around the mouth of a container with an inner diameter of 52.3 mm, the vertical Automatic detector characteristic value (ElectroDetectorValue) on the axis
And the vacuum value [Hl] is plotted on the horizontal axis, and I drew a characteristic curve graph of an automatic hammer tester that shows the correlation when the cover plate thickness is changed to O, 21mm2O, 26mm, O, and 32m7n. is shown in Figure 4.

The data of the pressure test of the sealed metal lid is shown in the table below.
From the above results, it can be seen that it is better for the characteristic curve of the automatic punch tester to have as large a slope as possible, and that when t=0.351 tm is exceeded, the accuracy decreases.

However, the pressure resistance against positive internal pressure during retort sterilization is at least 3.0k9/C if safety is included.
Since the standard cover plate thickness t is also limited to 0.26 degrees or more due to the requirement of ril, it is considered dangerous to make the metal cover of this type any thinner than this. This is the current situation.

In this project, it is an object of the present invention to provide a sealed metal lid for hammer testing that has good pressure resistance during retort sterilization and characteristics of an automatic hammer tester as good as conventional sealed metal lids, despite achieving the original objective of making the metal lid thinner. That is.

An embodiment of the present invention will be described with reference to FIGS. 5 to 7.

The sealing metal lid A of the present invention has a capacity of 0.17m1L to 0.1L.
In the center panel A of the conventional sealed metal lid C formed by a cover plate with a thickness of 23 mTfL, there is a peripheral raised inclined surface 2 which immediately rises from the peripheral edge 1 of the center panel A with an inclination angle θ of 10 to 30 laps. The raised height (hereinafter referred to as panel bite PH) is 0.21L1L to 1.0m7 over the entire center of the elevated panel surface 3 surrounded by ! It is formed as L.

Further, the radius of curvature R of the boundary area between the peripheral raised inclined surface 2 and the elevated panel surface 3 is curved to 3 mm or less.

Next, another embodiment of the present invention will be described with reference to FIGS. 8 to 10. The sealing metal lid B of the present invention is also 0.
In the center panel of the conventional sealed metal lid formed by a lid plate with a thickness of 17 mm to 0.23 mm, a horizontal portion 4 is left in an annular shape around the center panel, and the inclination angle θ is set to 10 to 30. The panel bite PH is set to 0.2 mm to 1.0 m7 over the entire center of the elevated panel surface 6 surrounded by the peripheral raised sloped surface 5 that rises up. It is formed by L.

Further, the bending angle α of the boundary area between the peripheral raised inclined surface 5 and the elevated panel surface 6 is bent to an obtuse angle of 150 m to 170 m.
Since the present invention has the above-mentioned shape, it has the same pressure resistance even though it is thinner by 0.03 to 0.0971 Lm than the thickness of the conventional sealed metal lid, and is suitable for automatic hammer testing equipment. It was possible to secure elevated panel surfaces 3 and 6 with good percussion vibration characteristics.

Furthermore, experiments on pressure resistance and characteristics of an automatic hammer tester using various cover plate thicknesses t and panel bite PH for a sealed metal lid X for a container having an inner diameter of 52.3 mm will be explained.

Experiment on the influence of 1PH on the sealed metal lid withstand pressure [See Figure 11] PRE-BUCKLINGPRESSUR is plotted on the vertical axis.
ECkg/C7l] and PH on the horizontal axis, and is a correlation graph when the cover plate thickness t is 0.23 mm and 0.2 iu.

Furthermore, what is PRE-BUCKLINGPRESSURE?
This is the internal pressure when a minute bend occurs based on the boundary area between the peripheral raised inclined surface 2 and the elevated panel 3.

2 Experiments on the characteristics of the automatic detection device [See Figure 12] The vertical axis shows the characteristic value of the automatic detection device (ElectrODetOrValu).
e) and the vacuum value [ClTLH9] on the horizontal axis, the lid plate thickness t is constant at 0.21 um, and the PH is 0.
It is a graph of each special line curve when it is set to mm, when it is set to 0.5 mm, and when it is set to 1.0 mm.

The data of the pressure test of the sealed metal lid A of the present invention are shown in the table below. From the above results, as the PH increases, the withstand pressure increases, but on the other hand, the accuracy of automatic perforation decreases. Considering the trade-off problem, even if the cover plate thickness t is 0.2.1 m 1 L or less, the PH can be set to 0.20 mm. If it is selected within the range of ~1.00 mm, it will have good pressure resistance and will also have good characteristics with an automatic hammer tester.

Also, the radius of curvature R is 3m77! It was also confirmed that when the value exceeds 1, the variation in the characteristic curve of the automatic percussion tester increases, and the percussion accuracy also decreases.

In the embodiments of the present invention, the sealed metal can lids A and B, which are sealed tightly over the mouth of the can container that is subjected to retort sterilization, have been described. It goes without saying that the hermetically sealed metal lid of the present invention can also be applied to containers.

Thus, the present invention contributes to resource saving and material cost reduction as a raised center panel that satisfies the requirements of thinning the lid plate thickness, pressure resistance, and automatic punching device characteristics at the same time, thereby reducing the cost of the disposable sealed container. It has excellent effects such as measuring.

[Brief explanation of the drawing]

Figure 1 shows the characteristic curves of an automatic punch tester showing various deformation behaviors of a conventional sealed metal lid with respect to the degree of vacuum. Figure 3 shows the cross-sectional view and plan view of the conventional sealed metal lid when the thickness of the lid plate is changed. FIG. 6 is a line sectional view, a plan view, FIG. 5 is an enlarged internal sectional view, and FIGS. 8 to 10 are examples of the sealed metal lid of the present invention. Fig. 9--line sectional view, plan view, Fig. 8-X internal enlarged sectional view, No. 11
Figure 12 is a graph of the characteristic curve of an automatic hammer tester when the lid thickness is kept constant and the PH is changed. be. A, B......Sealed metal lid for inspection, T...
Lid plate thickness, θ...Inclination angle, α...Bending angle, PH...Panel bite, R...Curvature radius, A...・Center panel, 1... Peripheral edge, 2, 5... Surrounding raised sloped surface, 3, 6.
...High panel surface.

Claims (1)

[Claims] 1 Lid countersink with lid plate thickness reduced to approximately 0.17 to 0.23 mm An upwardly facing elevated panel that has good automatic hammer tester characteristics and pressure resistance over the entire center area except for the peripheral area of the center panel. When forming the surface, the inclination angle of the surrounding raised inclined surface should be between about 10° and 30°, and the panel height should be about 0.
．． 2 to 1 mm, and the boundary area between the peripheral raised inclined surface and the elevated panel surface is curved to a radius of curvature of 3 mm or less, or bent at a bending angle of approximately 150° to 170°. Sealed metal lid.