JPH0621677Y2 - Tube mouth cutting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a cylinder mouth cutting device for cutting and removing a cylinder mouth that remains integrally connected to the mouth of an injection-molded plastic container.

(Prior Art) In injection molding of a plastic container (hereinafter referred to as a container), a cylindrical mouth remains in an integrally continuous manner at the mouth of the container. This tube mouth is cut and removed after the container is taken out of the mold.

Here, the finish of the mouth end face of the container with the tubular mouth cut severely affects the sealing property after filling the contents of the container, so a neat finish is required.

Conventionally, to cut the tube mouth of a container, a method of applying a blade to the cutting point while cutting the container and cutting, or inserting and holding the tube mouth into a holding hole provided in the fixed body, and moving the movable blade toward the holding hole There is a technique such as cutting back and forth by the guillotine method.

This invention belongs to a device that inserts and holds a cylindrical mouth of a container into a holding hole provided in a fixed body to move a movable blade forward and backward to cut the device. This device will be described with reference to the drawings.

FIG. 1 is a partial cross-sectional view of the tube mouth cutting device, and FIG. 2 is a plan view of a main part.

In the figure, reference numeral 1 denotes a fixed body, and this fixed body 1 is provided with a holding hole 2 for inserting and holding a barrel opening A of a container. A clearance-like through hole 4 is provided across the holding hole 2 in the fixed body, and a thin plate-shaped movable blade 3 is mounted in the through hole 4 so as to be movable back and forth. The movable blade 3 has its base connected to a reciprocating drive source 5 such as an air cinder.

As shown in FIG. 2, the blade edge of the movable blade 3 used here is an inclined blade 6 whose entire blade edge is inclined with respect to the moving direction a of the movable blade 3.

The procedure for cutting the cylindrical mouth A in such an apparatus will be described with reference to FIGS. 3 (a), (b), and (c).

In the figure, “o” indicates the center of the barrel opening, and line XX ′ indicates the center line of the barrel opening in the moving direction of the movable blade 3.

In the figure (a), the tube mouth A starts cutting from a position a which is shifted to one side from the central portion thereof.

Figure (b) The cutting edge goes out into the tube mouth A and the cutting points B and C are divided into two parts to proceed with the cutting.

(C) The cutting points B and C, which are divided into two parts, become one just before the cutting is finished, and the cutting is finished at the position D on the opposite side of the cutting start point a, and the tube mouth A is cut off.

(Problems to be Solved by the Invention) As described above, when the cutting edge of the movable blade 3 is composed of one inclined blade 6, as shown in FIG. 4 (a), the cutting approaches the end and the cutting edge and the uncut A gap C is formed between the inner surface B of the mouth of part A '.
In this state, the uncut portion A'has a thick wall and has an arc shape. Therefore, the cutting portion B'has a rigidity against the cutting pressure applied from the cutting edge to the cutting points B and C divided into two hands, so that the cutting can be performed. move on.

However, as shown in FIG. 4 (b), when the gap C disappears and the two cutting points B and C become one, the cutting length of the cutting edge into the uncut portion A ', that is, the cutting width l ₁ is a long length that combines the cutting widths of both cutting points (b) and (c). In this range, the uncut portion A'has a straight shape and the rigidity is drastically reduced. Therefore, the uncut portion due to the cutting pressure applied from the cutting blade In some cases, A'bends outward, and the barrel end A is peeled off so that a burr can be formed on the end face of the mouth, which is the cut face. This burr must be manually removed and the end face of the mouth must be corrected later, which is very troublesome.

The present invention has been made in view of the above points, and an object thereof is to provide a barrel mouth cutting device that improves the cutting blade of a movable blade and does not require correction processing of the end face of the mouth portion.

(Means for Solving the Problem) The gist of the present invention for achieving the above-mentioned object is to insert and hold a tube mouth into a holding hole provided in a fixed body, and move a movable blade forward and backward toward the holding hole. In the device for cutting the barrel mouth, the blade edge of the movable blade is formed into a horizontal blade parallel to the width direction by forming one side from the center portion into an inclined blade and retreating the remaining one side slightly from the inclined blade. It is a characteristic tube mouth cutting device.

(Operation) In the cutting of the tube mouth according to the present invention, the inclined blade precedes and cuts one side from the center of the tube mouth, and the other side is cut by the trailing horizontal blade.

Since the inclined blade finishes cutting at the center of the mouth before the side blade finishes cutting, the cutting width at the cutting point just before the side blade finishes cutting at this center of the mouth is only for the side blade. The change in the cutting width is small at the time when the gap between the blade edge and the inner surface of the cylinder mouth disappears and the uncut portion has a straight shape, and the cutting pressure from the blade edge is intensively applied to cut the uncut portion at once. The tube mouth can be separated.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

The basic structure of this invention is the same as that of FIG. The same parts as those in FIG. 1 will be described with the same reference numerals.

FIG. 5 is a plan view of an essential part of this invention corresponding to FIG.

In this invention, the cutting edge of the movable blade 3 is formed as a slanting blade 7 on one side from the central portion thereof, and the other side is formed as a horizontal blade 8 parallel to the width direction by slightly retracting from the slanting blade 7. .

By retracting the horizontal blade 8 from the inclined blade 7, a vertical edge 9 parallel to the traveling direction of the movable blade 3 is formed between the inner blade tips of the both blades 7, 8. The lengths of the inclined blade 7 and the horizontal blade 8 are set so that the vertical edge 9 is located slightly displaced to the horizontal blade 8 side from the tube mouth center line XX 'line (see FIG. 6) in the moving direction of the movable blade 3. Is set.

In the above structure, the procedure for cutting the barrel opening will be described with reference to FIGS. 6 (a), (b), (c) and (d).

In the figure (a), the inclined blade 7 precedes, and the tube mouth A starts cutting from a position e which is displaced from the central portion to one side.

(B) The cutting with the horizontal blade 8 is started from the end of the inner blade of the inclined blade 7 after the tip of the inner blade comes out inside the barrel opening at the center of the barrel opening.

(C) The inclined blade 7 finishes cutting at the central portion of the cylinder mouth opposite to the cut end, and the inner blade tip of the tilted blade 7 comes out of the cut end to the outside of the cylinder mouth.

(D) The vertical edge 9 is applied to the cut edge G and the cutting by the horizontal blade 8 continues, and when the cut edge G is reached, the cylinder opening A is cut off.

However, as in this invention, the blade edge of the movable blade 3 is the inclined blade 7
In the case of the horizontal blade 8 and the horizontal blade 8, as shown in FIG. 7 (a), the blade edge of the horizontal blade 8 and the uncut portion A'after the inclined blade 7 finishes cutting.
In the state where there is a gap C between the inner surface B and the inner surface B of the cylinder mouth, the uncut portion A ′ has an arc shape and exhibits rigidity against the cutting pressure applied from the cutting blade to the cutting point C to proceed with the cutting.

Then, as shown in FIG. 7 (b), at the time when the gap C disappears, the uncut portion A'indicates a straight shape within this range only by the cutting width l ₂ of the cutting point C by the horizontal blade 8. So
The cutting pressure from the cutting blade is intensively applied, and the uncut portion A ′ can be cut at a stretch.

(Effect of the Invention) According to the present invention configured as described above, when cutting and removing the tube mouth, one side is cut from the center of the tube mouth by the leading blade, and the remaining one side is cut by the trailing horizontal blade. Yes, after the inclined blade finishes cutting, just before the horizontal blade finishes cutting, there is no need to change the cutting width significantly because the number of cutting points divided into two in the past does not change greatly. The cutting pressure from the cutting blade is intensively applied to the short cutting width, and the uncut portion can be cut at a stroke to separate the tube mouth. Therefore, there is no burr on the end face of the mouth, which is the cut face, and the end face of the mouth is beautifully finished,
Productivity can be improved without the need for modification of the end face of the mouth.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of the tube mouth cutting device, FIG. 2 is a plan view of essential parts, and FIGS. 3 (a), (b), and (c) are explanatory views of a cutting procedure using a conventional cutting blade, and FIG. Figures (a) and (b) are explanatory views of the cutting procedure at the final stage of cutting, FIG. 5 is a plan view of the essential parts of this invention corresponding to FIG. 2, and FIGS. 6 (a), (b), (c). ) and (d) are explanatory views of the cutting procedure by the cutting blade of the present invention, and FIGS. 7 (a) and 7 (b) are explanatory drawings of the cutting procedure at the final stage of cutting. 1 ... Fixed body, 2 ... Holding hole, 3 ... Movable blade, 4 ... Through hole, 5 ... Reciprocating drive source, 7 ... Inclined blade, 8 ... Horizontal blade, A
...... Cylinder mouth.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. An apparatus for cutting a tubular mouth by inserting and holding a tubular mouth into a holding hole provided in a fixed body, and moving a movable blade forward and backward toward the holding hole to cut the tubular mouth. Is formed into an inclined blade, and the remaining one side is slightly retracted from the inclined blade to form a horizontal blade parallel to the width direction.