JPH0341319B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for trimming the mouth of a plastic container.

BACKGROUND TECHNOLOGY First of all, there is a conventional method for trimming the mouth of a plastic container and a procedure for attaching a lid to the mouth.
This will be explained based on FIG. First, as shown in FIG. 1A, a plastic container material 1 having a body 1A, a neck 1B, an expanded portion 1C, and a hole 1D is placed on a stand 2 in an inverted state, and an annular cutter 3 is fitted loosely into the body 1A. is lowered and the outer peripheral edge of the expanded portion 1C is cut to form a plastic container <<PET CAN>>. Next, as shown in Figure B, the container A is stood up, and after filling the container A with the contents, the lid 4 is placed on the mouth 1E, and then the outer periphery of the lid 4 as shown in Figure C. is wrapped tightly around the mouth portion 1E.

In the above structure, the expansion part 1C is formed by first forming the expansion part 1C, because if the mouth part 1E is directly formed by stretch blow molding, the strength of the mouth part 1E is too small. This is to cut the expanded portion 1C to form a strong opening portion 1E.

The problem that the invention seeks to solve The above conventional configuration has the following drawbacks.

Since the upper and lower plate-shaped parts of the expansion part 1C are cut at the same time, the cut part is likely to be distorted, and the mouth part 1E
The outer periphery of the lid 4 may not be a perfect circle, and a gap may occur between the lid 4 and the mouth portion 1E.

Since the cutter 3 is strongly pressed against the stand 2, the cutting edge of the cutter 3 wears out quickly. Therefore, it lacks mass productivity.

It is not possible to manufacture a container in which the diameter of the mouth portion 1E is smaller than the diameter of the body portion 1A.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for trimming the mouth of a plastic container that eliminates the above-mentioned problems.

Means for Solving the Problem In order to solve the above problem, according to the method for trimming the opening of a plastic container of the present invention, the expanded portion of a plastic container material having an expanded portion at one end is trimmed with a cutter along the central axis of the material. The material is cut along a direction perpendicular to the material, and then the outer peripheral edge of the cut portion is cut with a punch that moves along the central axis of the material to form a mouth portion of a predetermined diameter.

Embodiment Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 10. In FIG. 1, 6 is a preliminary cutting device for the plastic container material 1, 7 is a star wheel for feeding the material 1 into the preliminary cutting device 6, 8 is a material supply device for feeding the material 1 into the star wheel 7, Reference numeral 9 denotes a material carrying-out device for carrying out the material 1 whose upper half has been cut and removed by the preliminary cutting device 6, and 10 indicates the outer peripheral edge of the expanding portion 1C of the material 1 carried out by the material carrying-out device 9. The mouth shaping device 11 for cutting is a discharge chute for discharging the upper half of the expanded portion 1C cut by the preliminary cutting device 6, that is, the cutting waste 1F.

The material supply device 8 includes a conveyor 13 for conveying the material 1 in the direction of arrow A, and a body 1 of the material 1.
The first guide rail 14 supports the first guide rail A. A second guide rail 15 is provided outside the star wheel 7 and supports the body 1A of the material 1. The material carrying-out device 9 includes a conveyor 16 that conveys the material 1 in the direction of arrow F, and a third guide rail 17 that supports the body 1A of the material 1.

Next, the preliminary cutting device 6 will be explained based on FIGS. 2 to 8. In FIGS. 3 and 4, 19A is a central fixing plate of the machine frame 19, and a through hole 20 is formed in the center thereof. 21 is a bolt 22 attached to the outer peripheral edge of the through hole 20 on the fixing plate 19A.
The stopped center column, 23 is an annular lower thrust washer disposed on the lower end flange of the center column 21, 24 is an annular upper thrust washer bolted to the upper end of the center column 21, and 25 rotates on the lower thrust washer 23. A freely disposed first gear 26 is a turret 2 rotatably fitted onto the center column 21 via a bush 27 between the first gear 25 and the upper thrust washer 24.
Numeral 8 is a bolt that connects the turret 26 and the first gear 25, and 29 is an annular plate fixed to the outer peripheral surface of the turret 26, on which turntables 30 are rotatably arranged at appropriate intervals in the circumferential direction. There is. Reference numeral 31 denotes a rotary plate with a pair of upper and lower central through holes 32 provided above the annular plate 29, which are connected to each other by connecting rods 33, and semicircular recesses 34 are formed at locations facing each turntable 30. There is. 35 is a connecting rod that connects the lower rotary plate 31 and the annular plate 29 to each other, and 36 is a material support roller rotatably supported by brackets 37 arranged in each recess 34 at appropriate intervals in the circumferential direction. 38
is a rubber support plate disposed on the side of the rotary plate 31 over a section (α) (see FIG. 2).

In FIGS. 5 and 6, 40 is a cutter device, which is composed of the following items. 4
Reference numeral 1 denotes a swinging cylinder inserted into the through hole 20 of the fixed plate 19A and the center column 21, and the tip boss portion 43 of the swinging arm 42 extending horizontally from its lower end is attached to the lower surface of the fixed plate 19A. It is rotatably fitted onto a vertical shaft 44 provided thereon. 45 is a retaining plate fixed to the lower end of the vertical shaft 44; 46 is a rotary pipe rotatably inserted into the swing tube 41;
7 is a cutter with a heater 48 fixed to the upper end of the rotary pipe 46, and 49 is a cord of the heater 48, which extends downward through the rotary pipe 46. 50 is a first pulley fixed to the lower end of the rotary pipe 46; 51 is a cutter drive motor disposed below the vertical shaft 44; A pulley 52 is fixed. 53 is a first belt wound around both pulleys 50 and 52; 54 is a main body attached to a pin 55 on the machine frame 19;
The tip of the piston rod is connected to the swing arm 4.
2 is a swinging cylinder connected with a pin 56. By operating the cylinder 54, the cutter 47 can be swung around the vertical shaft 44 in the directions of arrows I and J.

What is shown in FIGS. 2, 7, and 8 is a cutting debris removing device 47, which is composed of the following components. A cam cylinder 58 is fixed to the lower surface of the top plate 19B of the machine frame 19 coaxially with the center column 21, and has a cam passage 59. Reference numeral 60 denotes a rotation shaft disposed at the center of the cam cylinder 58, and is rotatably supported by a boss 61 of the top plate 19B.
62 is an annular connecting plate fixed to the lower end of the rotating shaft 60, 63 is a boss fixed to the outer periphery of the connecting plate 62 directly above each recess 34, and 64 is inserted into each boss 63 so as to be able to move up and down only. A cam roller 65, which is a lifting rod and is provided at the upper end, is fitted into the cam passage 59. Reference numeral 66 denotes a backing plate disposed below each boss 63, and is connected to the annular connecting plate 62 by a connecting rod 67. Reference numeral 68 denotes a pair of L-shaped arms rotatably disposed at the lower end of the elevating rod 64 via a pin 69, and the arms 68 are connected to the holes 70 of each contact plate 66.
A vertical portion 68A inserted into the horizontal portion 68B,
A roller 71 arranged at the tip of the horizontal portion 68B
It is composed of. 72 is a spring disposed between a ring 73 screwed to the lifting rod 64 and the flange 74 of the arm 68, and urges the arm 68 downward to bring the vertical portions 68A into contact with each other; 75 is a spring; This is a hole-engaging protrusion formed at the lower end of each vertical portion 68A.

In FIG. 2, reference numeral 77 is a main drive motor, and a second gear 78 is fixed to its drive shaft via a coupling.The second gear 78 connects to the first gear 25 via a third gear 79. Linked together. 80 is a fourth gear fixed to the second gear 78 via a universal joint 81,
It is operatively connected to a sixth gear 83 fixed to the upper end of the rotating shaft 60 via a fifth gear 82 . In FIG. 3, 85 is a third pulley fixed to the lower end of the support shaft 86 of the third gear 79, and this third pulley 85 and the fourth pulley 87 of the star wheel 7 shown in FIG. A second belt 88 is wound around it. Therefore, the star wheel 7, rotating plate 31, and arm 68 rotate integrally in the direction of arrow C in synchronization. In FIG. 2, 89 is an operation control panel.

Next, the mouth shaping device 10 will be explained based on FIGS. 9 and 10. 90 is a horizontal plate supported by pillars 91 and has a material insertion hole 92. A two-part die 93 is disposed around the outer periphery of the material insertion hole 92 on the horizontal plate 90, and is composed of a fixed die portion 93A and a movable die portion 93B movable in the directions of arrows G and H. 94 is a die cylinder for moving the movable die portion 93B;
Reference numeral 5 denotes an annular protrusion formed on the inner circumferential surface of the die 93, which engages with the neck portion 1B of the material 1. Reference numeral 96 indicates four guide rods erected on the horizontal plate 90, reference numeral 97 indicates a fixing plate fixed to the upper part of each guide rod 96, and reference numeral 98 indicates a main body fixed on the fixing plate 97, and a piston rod attached to the fixing plate. A punch cylinder 97 extends downward through the punch cylinder 97, and a boss 99A provided on the outer periphery is an elevating plate that fits onto the guide rod 96 so as to be able to rise and fall. connected. A punch 101 is fixed to the lower surface of the elevating plate 99 and is fitted with the die 93. 102 is punch 1
Positioning hole formed in fixture 103 of 01, 1
04 is a positioning pin protruding from the upper surface of the movable die part 93B, and the positioning pin 104 becomes concentric with the positioning hole 102 when the movable die part 93B is completely fitted into the fixed die part 93A. It is something. Reference numeral 105 is an elevating arm that is fitted onto a pair of guide rods 106 provided on the lower surface of the horizontal plate 90 so as to be able to rise and fall freely, and an elevating rod 107 is inserted into a hole that is concentric with the punch 101 that is formed at the tip of the arm so that it can be moved up and down. It has been done. 108 is the lifting rod 107
A material support table is fixed above, 109 is a spring that urges the table 108 upward, 110 is a retaining nut that is screwed into the threaded portion at the lower end of the lifting rod 107, and 111 is fixed to the upper end of the lifting arm 105. It is a positioning block and has an arcuate surface 112 to which the body 1A of the material 1 is applied. Reference numeral 113 denotes a lifting arm cylinder that raises and lowers the lifting arm 105.

Hereinafter, the effects of the above configuration will be explained. First, the material 1 conveyed in the direction of arrow A by the conveyor 13 of the material supply device 8 is fitted into the recess 34 of the rotary plate 31 rotating in the direction of arrow C by the star wheel 7 rotating in the direction of arrow B, and placed on the turntable 30. (state shown in Figure 3). Next, the lifting rod 64 is pushed down by the cam passage 59 via the cam roller 65, and both vertical parts 68A of the arm 68 are inserted into the hole 1D of the material 1. Next, the roller 71 hits the contact plate 66, and both vertical portions 68A are separated from each other against the spring 72, and the seventh
The protrusion 75 engages with the hole 1D as shown by the imaginary line in the figure. Next, when the material 1 on the turntable 30 enters the (α) section, the material 1 on the turntable 30 is held between each roller 36 and the support plate 38, and due to the frictional force with the support plate 38, the material 1 on the turntable 30 is moved in the direction of arrow E. (state in Figure 4). Further, the cutter 47 is swung in the direction of arrow I by the swing cylinder 54 in advance to bring the cutter 47 close to the support plate 38, the heater 48 is energized to heat the cutter 47, and the cutter 47 is heated by the motor 51. Rotate it in the direction of arrow D. In such a situation,
When the outer peripheral surface of the expanding portion 1C of the material 1 rotating in the direction of arrow C while rotating in the direction of arrow E hits the cutter 47, the cutter 47
The expanded portion 1C is fused around the entire circumference, and the upper half of the expanded portion 1C separated by the fusion, that is, the cutting waste 1F, is integrally attached to the material 1 in the direction of arrow C while being supported by the arm 68. Move to. Next, the material 1 is guided by the third guide rail 17 of the material carrying-out device 9, carried out by the conveyor 16 in the direction of arrow F, and fed into the mouth shaping device 10. As the material 1 is carried out in the direction of the arrow F, the cutting chips 1F separated from the material 1 are brought above the discharge chute 11. Then, when the elevating rod 64 is raised by the cam passage 59,
Both vertical parts 68A of the arm 68 are brought into contact with each other by the spring 72, and the engagement between the protrusion 75 and the hole 1D is released, and the cutting chips 1F are moved to the discharge chute 1 by their own weight.
1 and is recovered. On the other hand, the material 1 that has entered the mouth shaping device 10 is applied to the arcuate surface 112 of the positioning block 111 by a predetermined feeding device (not shown) and placed on the table 108, as shown by the imaginary line in FIG. It will be done. Also, at this time, the piston rod of the die cylinder 94 is contracted to move the movable die portion 93B in the direction of arrow G and separate it from the fixed die portion 93A. Next, the piston rod of the lifting arm cylinder 113 is extended, and the table 108 is raised.
The material 1 on top is put into the die 93. Next, the movable die portion 93B is moved in the direction of arrow H by the die cylinder 94, and the annular protrusion 95 of the die 93 is moved.
is engaged with the neck portion 1B of the material 1 (solid line state in Fig. 10). Next, when the punch 101 is lowered by the punch cylinder 98, the outer circumferential edge of the expansion part 1C is cut by the punch 101 and the annular protrusion 95 of the die 93, and a plastic container I having a predetermined opening 1E is produced. be done.

In addition, during non-preliminary cutting such as during maintenance,
The cutter 47 is swung in the direction of arrow J by the swing cylinder 54 so that the cutter 47 does not hit the expanded portion 1C of the material 1.

Effects of the Invention As described above, according to the present invention, after the inflatable portion is preliminarily cut with a cutter, the outer periphery of the cut portion is cut with a punch to form a mouth portion of a predetermined diameter. The outer periphery of the can be made perfectly round, and the lid can be securely attached to the mouth. Also, since the cutter is not pressed against the table, the life of the cutting edge can be extended longer than before, making it suitable for mass production. Furthermore, it is possible to manufacture a container in which the diameter of the mouth portion is smaller than the diameter of the body portion.

[Brief explanation of the drawing]

1 to 10 show an embodiment of the present invention,
Fig. 1 is a schematic plan view, Fig. 2 is a front view, Fig. 3 is a partially cutaway front view of the main part of the preliminary cutting device, Fig. 4 is a view taken from - arrow in Fig. 3, and Fig. 5 is a front view of the preliminary cutting device. Fig. 6 is a partially cutaway front view of the vicinity of the cutter, Fig. 6 is a - arrow view of Fig. 5, Fig. 7 is a partially cutaway front view of the main part of the cutting waste removal device, and Fig. 8 is a partially cutaway front view of Fig. 7. - Arrow view, No. 9
The figure is a front view of the mouth shaping device, and FIG. 10 is a partially cutaway side view of the same figure. FIGS. 11a to 11c are explanatory diagrams showing a conventional method for trimming the mouth of a plastic container and a procedure for attaching a lid to the mouth. A... Plastic container, 1... Plastic container material, 1C... Expansion part, 1E... Mouth part, 6...
... Preliminary cutting device, 10... Mouth shaping device, 47...
...Cutter, 101...Ponchi.

Claims (1)

[Claims] 1. Cut the expanded portion of a plastic container material having an expanded portion at one end with a cutter along a direction perpendicular to the central axis of the material, and then cut the outer periphery of the cut point along the central axis of the material. 1. A method for trimming a mouth of a plastic container, comprising cutting with a moving punch to form a mouth of a predetermined diameter.