JPH01259237A - Method and instrument for inspecting strength of three-piece can - Google Patents

Abstract

PURPOSE:To securely inspect the strength of can transportation in any combination of in-can pressure, shell body plate thickness, and can height by inspecting the can transportation strength by measuring a reaction force. CONSTITUTION:A can which is conveyed on a conveyor is clamped by belts 3 and 3', sent to a reaction force measurement part, and carried to between a gauge roller 12 and a load cell contactor 14 as a 1st reaction force measuring means to measure the reaction force. The output of the load cell is read in a CPU. Then the can while rotated moves to between a gauge roller 13 and a contactor 15 as a 2nd reaction force measuring means to measure a reaction force similarly. The output of the load cell of the 2nd reaction force measuring means is read in the CPU and compared with the output of the load cell which is already stored to employ a smaller value, which is compared with a preset reference value to make a normal/abnormal decision, so that a rejection signal is generated when the can is acceptable.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method and apparatus for testing the strength of piece cans, particularly piece positive pressure cans.

Conventional technology canned food is susceptible to shocks during transportation, drops from vending machines, etc.
Canned goods are subjected to various shocks during the distribution process, but in order to maintain their commercial value, cans must not be deformed even when subjected to these shocks. To achieve this, the can must have a certain level of strength (hereinafter referred to as transportation strength) that allows the can to withstand impacts during the distribution process, that is, even if the can is displaced by a certain range of external force during the distribution process, the external force is removed. If so, strength is required to allow it to be restored to its original shape. Traditionally, in the case of piece cans, strong can materials such as relatively thick tin cans were used, which can withstand shocks during the distribution process, but recently, from the perspective of resource conservation, even thin piece cans have been used. Attempts have been made to use relatively weak can stock such as can stock. In the case of these cans, to supplement the strength of the can material, the inside of the can is filled with liquid nitrogen to create positive pressure.

A device for testing the strength of this type of 3-piece positive pressure 6; has not yet been provided, and conventionally, the can internal pressure was measured using a can internal pressure measuring device. The strength of the can is determined based on the I value.

Conventionally, as a device for measuring can internal pressure, there is a percussion machine that applies an electromagnetic pulse to the can lid, detects the generated vibration, and determines whether the internal pressure is good or not (for example, the Japanese Patent Publication No. 49-71 Publication No. 92, JP-A-53-:1.244
Publication No. 92). However, the punching machine can be used for lids with protrusions such as easy-open cans, and
It is also unsuitable for testing the internal pressure of positive pressure cans that are filled with inert gas to raise the internal pressure above atmospheric pressure. Therefore, the present inventor has devised a system that can accurately measure the internal pressure of positive pressure canned goods even if there are protrusions on the lid or manufacturing errors in the can body, instead of the conventional punching machine.
Assuming that the pressure is constant, the same part of the can body is pushed in with different pushing amounts to locally displace it, the reaction force for each displacement is determined, and the difference in reaction force is converted to the internal pressure of the can. provided an internal pressure measuring device for detecting the internal pressure of canned goods.
9-1573.7).

Problems to be Solved by the Invention The transportation strength of a piece can can be expressed by the reaction force when the can body is slightly displaced. This reaction force is related to can internal pressure and can body plate thickness, and if the plate thickness is the same, it is related to can internal pressure and can height.The higher the can internal pressure and the thicker the can body plate, the higher it becomes. increases as the can height decreases and the can internal pressure increases. No matter what combination of can internal pressure, can body plate thickness, and can height,
If the reaction force when the product is displaced by a predetermined amount exceeds a certain value, the strength to withstand transportation can be guaranteed.

Therefore, the strength of the can can be tested by measuring the reaction force of the can against minute displacement and checking whether the 4I value is within a predetermined range. However, when the conventionally provided reaction force measuring means as the can internal pressure inspection device is applied to the reaction force measuring means of a three-piece can, the piece can Therefore, when the side seam or measuring part hits the side seam, the reaction force increases significantly by -'1, and the correct reaction force of the can body becomes al! There is a problem that it becomes impossible to determine the

The present invention was created in view of the actual situation described in 1.
A can strength test for piece cans that can accurately measure the reaction force of a piece can even when the size 1-seam part hits the measuring part, and thus can accurately and easily test the can strength of a piece positive pressure can. It is an object of the present invention to provide a method and apparatus thereof.

Means for Solving the Problem The above purpose is to press different parts of the can body of a piece can with the same amount of push, to locally slightly displace the can body, and to combine the reaction forces against each displacement. This can be achieved by adopting a can strength testing method characterized in that the strength of a three-piece can is tested by measuring the 4I values and comparing the smaller measured value with the base value.

In addition, 5 above [the device for achieving the purpose is a first reaction force measuring means comprising a gauge roller and a row 1 to cell contactor arranged at a distance slightly narrower than the outer diameter of the can body across the can transfer path. ,
provided downstream of the first reaction force measuring means in the can transport direction;
a second reaction force measuring means in which a gauge roller and a load cell contactor are arranged at the same spacing as the spacing between the gauge roller and the load cell contactor of the first reaction force measuring means; and the first reaction force measuring means. and a can transfer means for rotationally transferring the can between the second reaction force measuring means and the second reaction force measuring means.

By rolling the can between two sets of measuring sections whose spacing is adjusted to the same size, pushing the can by the same amount of pushing, and measuring the reaction force at that time, at least one set of measuring sections It is possible to measure areas that avoid the side sea area 11. If one i1+1 constant part is site sea 13
When measuring a part, the measured value of that part will naturally be higher than the measured value of other parts. Therefore, the two measured values are compared, and the smaller value becomes the reaction force at the part avoiding the size 1 and sea 11 parts, and becomes the reaction force representing the actual can strength.

The can strength is determined based on whether the low measured value is higher or lower than the base 1 (+1) value for having a preset transport strength.

EXAMPLES Hereinafter, specific examples of the present invention will be described in detail based on the drawings.

The drawing shows an embodiment of the device according to the invention.

In the figure, reference numeral 1 denotes a main body of the detection device, which is installed on a pole 2 erected next to a can conveyor on a can manufacturing line so as to be adjustable up and down by a rack and pinion mechanism.

A and 3' are a pair of round healds provided under 1 for transporting the canned goods by holding the bodies of the cans, and a support plate 5 is provided on the main body frame so that the spacing can be adjusted.
The suspension is passed to a pair of pulleys 6.7 and 6', 7' under the length supported by s9, ]○.

The pulley 6.6' is rotated by the motor 8, and rotates the round heel 1~ in synchronization with the can conveyor.

12.13 are gauge rollers of the first and second reaction force measuring means, and 14.15 are load cells of the first and second reaction force measuring means, which are provided facing the gauge rollers and the can transfer path, respectively. It is a contact element. The distance between each set of gauge rollers 2.13 and the contactor 14.15 of the load cell is set such that one set is slightly narrower than the outer diameter of the can body, and the distance between the two sets is equal. ing. As shown in FIG. 3, two grooves are formed in the cage roller 12 and 13 marked 11M so that the round belt 3' fits therein and the round belt 1~ surface and the roller surface are approximately on the same level. The roller surface contacts the body of the can passing through the measuring section. In addition, on the load cell side, as shown in Figures 2 to 4, there is a soft material in the vicinity of where the contacts 14 and 15 are located, in order to provide frictional resistance to the can and ensure rotational movement of the can. A transfer plate 4 made of rubber is arranged so as to be located slightly outside the transfer path from the tip of the contact, and the round belt 3 is located further outside of the transfer path. Therefore, the transfer path is connected to the round bells 1-
When the can, which has been transferred while being held between
While receiving frictional resistance in contact with the belt 3' on the gauge roller side and the gauge roller,
The can body is fed between the gauge roller and the contactor, and the can body is pushed in by a predetermined amount, and the reaction force at that time is transferred to rotate the can by the round bells 1 to 3' and the transfer plate 4 in the load cell side embodiment. However, the rotary transfer means is not necessarily limited to this configuration.

As shown in FIGS. 2 and 3, the contactor shape of the load cell is formed in the shape of an ellipse whose major axis is in the vertical direction for the reasons described below.

The reaction force obtained by pressing the can body is proportional to the area of the can body that is slightly deformed if the amount of pushing is constant, and is approximately proportional to the internal pressure of the can. This deformation area almost matches the contact area, so
The reaction force is proportional to the product of the can internal pressure and the contact area. Therefore, in order to increase the gain of the reaction force against the internal pressure, the area of the contact is preferably large.

However, if the contactor is made larger in the direction of travel of the can, an unbalanced load will be applied to the row 1 cell when the can is dented, causing the diaphragm to which the strain gauge is attached to vibrate in an S-shape.
The true maximum load may not be obtained and measurement errors will increase. Therefore, as mentioned above, the can is shaped into an ellipse that is long in the height direction and short in the direction of travel. Furthermore, the R in the height direction is set large to prevent dents and scratches on the can body, and the R is set small in the direction of travel so that the maximum load can be accurately obtained and the can can be gripped smoothly. It is.

16.17 is a can detection sensor provided directly above the contactor 14.15 of the load cell. Can detection sensor 1
7 also serves as a timing sensor for the buckling sensor described later. The above round belt 3, pulley 6.7,
Load cell contact 14.15, can detection sensor 16.1
7 are both provided on the support frame 10, and are moved together by operating a width adjustment handle 11, so that the width of the can transfer path can be adjusted according to the diameter of the can body of the can.

Reference numeral 20 denotes a backlink sensor consisting of, for example, an electromagnetic induction loss type displacement meter, which is provided to detect the backlink phenomenon of a can lid. The can transport path is provided so as to be located above the center of the can transfer path. In the bank link sensor, when the can detection sensor 17 detects the tip of the can body, the center of the can is located directly below the buckling sensor, so that displacement of the center of the can lid can be detected. .

In addition, in the figure, 18 is a huff 1-rule for vertically moving the main body of the device;
19 is a lock lever.

Inspection of can strength is carried out in the following manner using the apparatus configured as described above.

The cans 22 transferred on the conveyor have bells 1 to 3.3.
'', the can is sent to the reaction force measuring section, and the can is inserted between the gauge roller 12, which is the first reaction force measuring means, and the load cell contactor 14, which has a spacing slightly narrower than the outer diameter of the can body. The shell is pushed in and undergoes a slight displacement.The contactor is pushed by the reaction force of the can body at that time, a load is applied to the row 1 to cell, and the reaction force is measured.The output of the load cell is detected by the can position detector 18. Depending on the signal, for example, the maximum measured value is held in a peak holding circuit of a control circuit (not shown), switches an analog multiplexer, is converted into a digital signal by an A/D converter, and is read into the CPU.Subsequently,
Can 22 is subjected to a tangential force on one side by bell l-3', and no! As a result of the friction applied by the rolling plate 4, the first side enters between the gauge roller 13, which is the second reaction force measuring means, and the contactor 15 while rotating, and the reaction force is similarly measured. At that time, the distance between the gauge roller 13 and the contactor 15 is
Since this is the same as that of the first reaction force measuring means, the can body is pushed in by the same pushing amount by the surface measuring means. Since the can rotates, the second pushing means
A region pushed by the pushing means and another region are pushed. The output of the load cell of the second reaction force measuring means is held at its maximum value by the peak holding circuit in the same manner as described above, and
/D conversion is read into the CPU, compared with the previously stored output of the load cell, the smaller value is adopted, and this value is compared with the reference value sent to Bricella 1 to determine pass/fail. In case of failure, a ejection signal is generated.

Further, when the tip of the can body is detected by the can detection sensor 17,
The buckling sensor 20 detects the center position of the can lid,
The CPU calculates the displacement from the set value to determine pass/fail, and if the displacement is outside the allowable range, reject No. 1-3 is issued.

When a reject signal is issued, a rejector (not shown) is activated to remove the defective can from the line.

Although a preferred embodiment of the present invention has been described above, the device of the present invention is not limited to the device of the above embodiment. Various design changes are possible within.

The invention consists of the structure described above, and since the transportation strength of the can is tested by measuring the reaction force, it is possible to inspect the transportation strength of the can by measuring the reaction force. It is also possible to reliably test the transport strength of cans. In addition, since the reaction force is measured when different parts of the can body are pushed in with the same amount of push, -]2- In at least one measurement part, the part that avoids the side seam is measured, and the reaction of the can body is accurate. The force can be measured, thereby allowing the transport strength of the piece can to be properly tested.

In addition, the device of the present invention has a compact structure because it only requires arranging the first reaction force measuring means and the second reaction force measuring means along the transfer conveyor, and arranging the can transfer means for rotationally transferring between them. It can be easily integrated into existing canning production lines.

[Brief explanation of the drawing]

The drawings show one embodiment of the piece can strength testing device of the present invention, FIG. 1 is a plan view thereof, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. 3 is a front sectional view of a measuring section. FIG. 4 is a front sectional view between the measurement parts. 1: Inspection device main body 3.3': Round belt 4: Rolling plate 5: Main frame 8: Motor 9, 10 Support frame 12, 13: Gauge roller 14, 1
5: Load cell contact 16.17: Can detection sensor 20: Buckling sensor 22: Can

Claims (1)

[Claims] 1) Press different parts of the can body of a three-piece can with the same pushing amount to locally slightly displace the can body, and measure the reaction force for each displacement. A can strength testing method characterized by testing the strength of a three-piece can by comparing the smaller measured value with a reference value. 2) A first reaction force measuring means formed by arranging a gauge roller and a load cell contact across the can transfer path at an interval slightly narrower than the outer diameter of the can body, downstream of the first reaction force measuring means in the can transfer direction. a second reaction force measuring means provided in the first reaction force measuring means, the second reaction force measuring means having a gauge roller and a load cell contact arranged at the same interval as the interval between the gauge roller and the load cell contact of the first reaction force measuring means; A can strength testing device for a three-piece can, comprising a can transfer means for rotationally transferring the can between the means and the second reaction force measuring means.