JP3251406B2 - Abnormal inspection method for can contents - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting for abnormalities such as deterioration due to decay of the contents of cans, and more particularly, to inspecting for abnormalities such as deterioration of contents by measuring the internal pressure of a can. On how to do it.

[0002]

2. Description of the Related Art In cans filled with foods and beverages as contents and sealed, if the sterilization is insufficient or the sealing is incomplete, the contents will rot and deteriorate, causing harm to the human body. Therefore, there is a need for sanitary problems. Therefore, it is required to surely eliminate defective cans that have leaks or deteriorated contents before shipping.

[0003] Therefore, in order to be able to grasp defective cans with certainty, the contents are sealed in a heated state so that the inside of the can is brought into a negative pressure state after cooling, so that incomplete sealing is achieved. A change in the internal pressure of the can due to leakage due to gas generation and gas generation due to decay of the contents is detected by a beating device (see Japanese Patent Application Laid-Open No. 53-119087, etc.) Conventionally, it has been generally performed that the bulge can be easily identified by observing the bulge from the outside.

On the other hand, in recent years, from the viewpoint of resource saving and low cost, in order to reduce the use of aluminum alloy sheets and surface-treated steel sheets as cans, even if the contents are non-carbonated beverages, the can body is as thin as possible. Many positive pressure cans have been produced in which the internal pressure of the can is made higher than the external pressure by adding liquid nitrogen or the like and the shape of the can is maintained, but in such positive pressure cans, Since it is difficult to detect a defective can with the same method for detecting the can internal pressure as the above-described negative pressure can, a method for measuring the can internal pressure of the can more accurately to cope with this is necessary. A method for detecting minute leakage from a device or a can has been already proposed. (For example, JP-A-62-162937, JP-A-64-435, JP-A-2-28403)
No. 3 publication etc.)

[0005]

By the way, even in a positive pressure can where the internal pressure of the can is made higher than the outside air pressure, if the contents rot and deteriorate, gas is generated and the internal pressure of the can further increases. By using a device that can accurately measure the internal pressure of the can, it measures the internal pressure of each of the cans after filling and sealing the contents of the can and gives the reference value, and then again when shipping from the manufacturing plant By measuring the internal pressure of each can and comparing those measured values to the initial reference value, it is possible to determine whether or not the contents of each can have deteriorated due to decay from production to shipment. It is considered possible.

However, in practice, in positive pressure canning such as drawing and ironing in which the internal shape of a can is maintained by forcibly increasing the internal pressure of the can using liquid nitrogen or the like, even if the same contents are canned, the contents are stored in the can. Since the internal pressure of the can at the time of sealing greatly varies, even if the internal pressure of the can is accurately measured at the shipping stage after the lapse of a predetermined time and compared with the initial reference value, the deterioration of the contents in each can It is difficult to make an accurate determination, so, for example, for foods that are easily perishable using dairy products containing heat-resistant high-temperature bacterial spores, such as milk coffee, tin and aluminum alloys are required for quality control. A problem arises that it is difficult to use a wrung and ironed can made of iron.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the above-mentioned conventional method for inspecting the abnormality of can contents, and more specifically, when a predetermined time has elapsed after the production of cans, Abnormal inspection of can contents that can be accurately determined by using a conventional can internal pressure measuring device, etc., without using a complicated can internal pressure measuring device, as to whether or not abnormalities have occurred in the contents due to decay. It is intended to provide a way.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems and to achieve the object, the present invention relates to a method for inspecting an abnormality in can contents, which comprises the steps of: Is measured, and the measurement result is displayed at a predetermined position on the outer surface of each can, and after a predetermined time has elapsed since the initial measurement of the can internal pressure, the can internal pressure is measured again for the can. It is characterized by comparing the measurement result with the initial can pressure displayed on the surface of each can to determine whether there is any abnormality in the contents of each can.

In the above-described method for inspecting an abnormality in the contents of a can, the can surface temperature is measured at substantially the same time as the initial measurement of the internal pressure of the can. A can pressure correction value that predicts and calculates the can pressure when the temperature reaches a predetermined reference temperature is displayed on the outer surface of the can as a measurement result, and the can pressure after a predetermined time elapses. Is re-measured in a state where the cans are at a predetermined reference temperature.

[0010]

[Operation] With the above configuration, first, at the time of measuring the internal pressure of the can at the time when the can is manufactured, the internal pressure required for maintaining the shape of the can is determined by observing the measurement result of the internal pressure of each can. It is possible to check for defective cans such as those that have not been made or that the sealing state of the can is poor and there is leakage (leak).

Further, after a lapse of a predetermined time from the initial measurement of the internal pressure of the can, that is, at the time when it is necessary to judge whether or not the contents of the can have decayed before shipment, the internal pressure of the can is measured again, and each can pressure is measured. By comparing the measurement results for each can with the initial measurement values displayed on the can surface of each can, even if the initial internal pressure varies due to individual cans, accurate It is possible to detect an increase value or a decrease value (in the case of slow leak canning) of the internal pressure of each can, and to accurately determine whether or not the contents of the can have decayed, and to detect a slow leak can. You can also.

It should be noted that the can surface temperature is measured at substantially the same time as the initial can pressure measurement, and a can pressure correction value obtained by predicting and calculating the can pressure when the can reaches a predetermined reference temperature based on the can surface temperature is calculated. By displaying the can pressure correction value on the outer surface of the can as a measurement result, it is possible to measure the can pressure inside the can immediately after heat sterilization, or to mix cans at various temperatures. Even in such cases, the rise or fall of the internal pressure of each can can be accurately detected for each can, even though the range of temperature change varies depending on the individual can. It is possible to accurately determine the presence or absence of decay of an object.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for inspecting an abnormality of can contents according to the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an entire apparatus for carrying out a method for inspecting an abnormality of can contents according to the present invention. A can pressure measuring apparatus 11 for measuring an initial can pressure of a manufactured can 10 is shown. A cylindrical and rotatable receiving roll 13 is arranged on one side of the can 10 placed and conveyed on the belt conveyor 12, and a measuring roll 14 whose outer peripheral surface has a middle-high shape is arranged on the other side. Are also rotatably arranged, and the measurement roll 14 is supported so as to be able to advance and retreat in the center direction of the can 10, and the advance and retreat state of the measurement roll 14 is transmitted to a load detector 16 such as a load cell via a support shaft 15. The can pressure measuring device 11 having such a structure is already known from, for example, Japanese Patent Application Laid-Open Nos. 59-1557537 and 62-162937. It is.

The can pressure measuring device 11 includes a receiving roll 1
The measuring roll 14 is advanced and retracted according to the internal pressure of the can 10 passing through the gap between the measuring roll 14 and the measuring roll 14, and the load value at the time of the advance and retreat is detected by the load detector 16.
6, the can pressure can be detected by checking the output of the can 6.
The output signal from the load detector 16 is a load value correction circuit 2
Is input to

An infrared sensor 3 for measuring the can surface temperature of the can 10 at the time of measuring the can internal pressure is arranged near the can internal pressure measuring device 11, and the temperature of the can 10 measured by the infrared sensor 3 is measured. Is output to the temperature correction circuit 4. Since the can is mainly made of a steel plate or an aluminum alloy plate having good heat conductivity, the surface temperature of the can is substantially equal to the temperature in the can.

The temperature correction circuit 4 stores a change characteristic of the can pressure (load value) depending on the temperature of the can. The actual temperature of the can 10 input from the infrared sensor 3 and a predetermined reference temperature (for example, 20 (° C.) is output from the temperature correction circuit 4, and the correction coefficient signal is input to the load value correction circuit 2.

The correction coefficient signal output from the temperature correction circuit 4 is used as means for correcting the internal pressure of the can, and the load value output from the load detector 16 and input to the load value correction circuit 2 is converted into a predetermined value. This is for correcting the load value (correction can internal pressure value) at the reference temperature.

The predetermined reference temperature is set at a temperature close to the temperature at which the can is cooled and returned to the normal temperature state after the can is filled with the contents and sealed, and further subjected to a heat treatment. For example, it is preferable to set to 20 ° C.).

The can 10 whose can inner pressure is measured by the above-mentioned can inner pressure measuring device 11 and whose can surface temperature is measured by the infrared sensor 3 is conveyed by a belt conveyor or the like and sent to the ink jet printer 6.

The ink jet printer 6 is for displaying the corrected can pressure value output from the load value correction circuit 2 at a predetermined position on the outer surface of the can of the can 10, and receives a signal from the load value correction circuit 2. The printing operation is controlled by the printer controller 5 and the characters and symbols indicating the corrected can internal pressure value, for example, specific numbers, bar codes or marks are printed on the bottom 10b of the can 10.

As shown in FIG. 2, the can 10 sent to the ink-jet printer 6 so that the can bottom 10b is opposed to the ink printer 6 has a date of manufacture printed on the can bottom 10b. A character 10c or the like indicating the correction can internal pressure value is printed on the lower side.

After the measurement of the initial can pressure as described above, the measurement results (corrected to the can pressure value at the predetermined reference temperature) are individually printed on the can bottom 10b. The same as the can internal pressure measuring device 11 in a state before the shipment after a lapse of a predetermined time, that is, at a time when the contents of the can are finally to be inspected and each can 10 is at a predetermined reference temperature. The internal pressure of each can is measured again by the internal pressure measuring device 21 having the above structure.

At this time, a reader 8 is installed in the vicinity of the can pressure measuring device 21 so as to face the bottom 10b of the can 10 to be measured, and for each can 10, the load of the can pressure measuring device 21 is measured. At the same time as the load value indicating the can pressure at the time is output from the value detector 26 and input to the comparison determination circuit 7, a character 10 c indicating the corrected can pressure value displayed on the can 10 is read by the reader 8. And a signal output based on the read signal is input from the reader 8 to the determination comparison circuit 7.

Then, the judgment and comparison circuit 7 compares the read corrected can pressure value with the can pressure value at that time.
If the difference is equal to or greater than a predetermined value, it is determined that the contents of the can are abnormal, and an abnormality detection signal is output. The abnormality detection signal output from the comparison determination circuit 7 is input to the display means 9 and displayed. The means is notified to the outside through the means 9 by voice or lamp lighting display.

As described above, one embodiment of the method for inspecting an abnormality of can contents according to the present invention has been described together with an apparatus for carrying out the method. However, according to such a method, individual cans are detected at the time of detecting defective cans. In comparison with the case where the internal pressure of the can is measured and compared with a predetermined reference value to determine the presence or absence of decay of the contents, even if the internal pressure of the can initially varies, a determination failure occurs. The fear can be reliably eliminated.

That is, in the case of using a drawn ironing can for maintaining the shape of the can by forcibly increasing the internal pressure of the can using liquid nitrogen or the like, the average value of the internal pressure of the same contents when the can temperature is 20 ° C. at 1.5 kg / cm ² at a different canned the individual canned cans internal pressure has vertically 0.2 kg / cm ² about the variation from the average value, is 1.3 kg / cm ^2, high in low 1.7kg / c
It has a m ² about the can internal pressure values.

When the presence or absence of decay of the contents of such a can is determined by comparing it with one reference value, for example, 0.3 kg / cm after one week based on the average value of the internal pressure of the can of 1.5 kg / cm ^{2. 2} or more (1.8 kg
/ Cm ² ), if there is a possibility of decay, if the internal pressure of the can was 1.7 kg / cm ^{2 at} the beginning, the internal pressure of the can was changed only about 0.1 kg / cm ² without fear of decay. Even if not, it will be determined that there is an abnormality

On the other hand, if the internal pressure of the can increased to 0.4 kg / cm ² or more one week later (1.9 kg / cm ² or more) with respect to the reference internal pressure of 1.5 kg / cm ² , there is a possibility of decay. However, even if the internal pressure of the can was initially only 1.3 kg / cm ² , it was judged that there was still an abnormality even if the internal pressure of 0.5 kg / cm ² or more was extremely likely to rot, even if the internal pressure was increased. It will not be done.

However, according to the method as in the above embodiment, the value used as the criterion for determination is based on the initially measured can pressure inside each can. Irrespective of this, it is possible to grasp the accurate change state of the internal pressure of each can.

Further, in the above embodiment, the reference value for the judgment is not the can pressure itself measured at the beginning, but the can pressure correction value for predicting and calculating the can pressure at the predetermined reference temperature. Therefore, when the initial can pressure was measured for cans immediately after heat sterilization was performed,
Even when cans of various temperatures are mixed at the time of the initial measurement of the internal pressure of the can, it is possible to obtain accurate values for each of the It is possible to comprehend the changing state of the can internal pressure.

Although the method of the present invention has been described based on one embodiment, the present invention is not limited to such an example. In the case where the initial can pressure is measured at the time when all of them are at the predetermined reference temperature, the infrared temperature sensor 3, the temperature correction circuit 4, the load value correction circuit 2
There is no necessity, and the present invention can be implemented by directly inputting the output from the load detector 16 to the printer controller 5 and displaying the measured initial can pressure value itself on the can 10. The printing of the internal pressure value is not limited to the bottom of the can, but may be performed on a can lid or a can body.

Further, in the above-described embodiment, the comparison / judgment circuit 7 and the reader 8 are used to grasp the change state of the can internal pressure. However, the present invention is not limited to the case of using such an apparatus for automation. The operator can visually check the bottom 10 of the can 10
It can also be carried out by checking the numerical value and the like displayed in b and comparing the can pressure value output from the load detector 26 of the can pressure measurement device 21 with this to directly determine the presence or absence of an abnormality such as rot. It is something.

[0034]

According to the method for inspecting an abnormality of can contents according to the present invention as described above, the presence or absence of an abnormality due to decay of the contents of a can is complicated even if the initial internal pressure of the can varies. The determination can be made accurately by using a conventional can internal pressure measuring device or the like without using the can internal pressure measuring device, and it is also possible to detect a slow leak can.
Also, by correcting the initial can pressure value to the can pressure value at the reference temperature, the initial can pressure can be measured immediately after heat sterilization or in a state where cans of various temperatures are mixed. In this case, it is possible to accurately determine whether there is an abnormality due to decay of the contents.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing an entire apparatus for carrying out an embodiment of a method for inspecting an abnormality of can contents according to the present invention.

FIG. 2 is a perspective view of an ironing and squeezing can showing an example of canning in which the initial measurement result of the can internal pressure in the present invention is displayed at a predetermined location on the outer surface.

[Explanation of symbols]

 2 Load value correction circuit 3 Infrared temperature sensor 4 Temperature correction circuit 5 Print controller 6 Inkjet printer 7 Comparison judgment circuit 8 Reader 10 Can 11 Can internal pressure measuring device 13 Receiving roll 14 Measurement roll 16 Load detector 21 Can internal pressure measuring device 23 Receiving Roll 24 Measurement roll 26 Load detector

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 7/00 G01L 5/00 G01M 3/00 JICST file (JOIS)

Claims (2)

(57) [Claims] An internal pressure of a can which is filled and sealed is measured, and the measurement result is displayed at a predetermined position on an outer surface of each can, and the initial internal pressure is measured. After a lapse of a predetermined time from the time, the internal pressure of the can is measured again, and the measurement result is compared with the initial internal pressure indicated on the surface of each can to obtain the content of each can. An abnormality inspection method for can contents, which is characterized by determining the presence or absence of an abnormality. 2. The can surface temperature is measured at substantially the same time as the initial measurement of the can internal pressure. Based on the measurement results of the can internal pressure and the can surface temperature, the can internal pressure when the can reaches a predetermined reference temperature is determined. Predicted and calculated can pressure correction value is output, and the can pressure correction value is displayed on the outer surface of the can as a measurement result, and the can pressure is re-measured after a predetermined time has passed, and the can is measured at a predetermined reference temperature. 2. The method according to claim 1, wherein the inspection is performed in the state of (1).