JPH042492A - Press-cutting device - Google Patents

Abstract

PURPOSE:To press the flange of the main body of a plastic made container with good accuracy, by heating in advance the container main body by a preheating device and feeding it to a press device after maintaining it at the specific temperature. CONSTITUTION:A container main body 45 is fed to a receiving part 52 side in the state of being heated by the temperature adjusting box 50 of a feed pipe 28, heated further by the hot air fed from a hot air pass 54 prior to being installed to the receiving part 52 and heated to about a constant temperature without depending on the circumferential environmental temperature. The container main body 45 transferred onto a press male die 21a is heated to the specific temperature and about a constant shape is maintained without depending on the change in the environmental temperature, so the expansion or contraction is prevented and the container main body 45 can surely be installed without its eccentricity to a guide 25.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a press-cutting device for press-cutting a flange portion of a plastic container body used in a container with a metal lid.

(Prior Art) Metal containers, such as metal cans, have various shapes, but can be classified into three-piece cans and two-piece cans based on the structure of the can body. A three-piece can, also known as a tin solder can, has a cylindrical body, lid, and bottom sealed with double seams.

On the other hand, a two-piece can is also called a stamped tin can, and has a structure in which the body and bottom (container body) are integrally molded, and the lid is double-sealed.

These metal cans are used as food packaging containers for various canned foods, juices, soft drinks, jams, dried foods, etc., and are rigid containers with particularly excellent sealing and preservation functions. However, metal cans have some points that should be improved as described below. That is, (1) Since it is a metal can, there is a limit to its weight reduction.

■ If it is crushed by an impact, it will not recover and will be deformed.

■ Compared to plastic containers, the energy cost of manufacturing them is higher.

■ If the display effect of the container exterior is made of metal, it cannot be changed freely and the only means of exterior packaging is printing.

■ It is impossible to create transparent containers that allow the contents to be checked without opening the can.

In order to solve these drawbacks of conventional metal cans,
Containers with metal lids have been proposed in which the peripheral edge of a metal lid is wrapped around the flange of a plastic container body.

In addition, as a method for manufacturing plastic container bodies, a plastic sheet having the thickness necessary for container formation is heated using a general thermoforming method, and a mold is used to form a molded product of the container body with a flange. A method has been considered in which the thickness of the flange is reduced, and then the flange is cut to a predetermined width. The reason why the flange portion is press-cut in this way is to perform appropriate seaming and tightening between the flange portion and the peripheral edge portion of the metal lid.

(Problem B to be Solved by the Invention) As mentioned above, when manufacturing a plastic container body, it is necessary to properly seal the container with the peripheral edge of the metal lid to obtain a container with a metal lid with high precision. It has been proposed to press the flange portion of the container body to a predetermined thickness, and then cut the outer periphery of the flange portion to a predetermined width.

By the way, when pressing the flange portion of the container body, the flange portion is pressed by a press device including a male press die, a female press die, a guide for fixing the container body, and the like. However, since the container body is made of plastic, it may expand or contract depending on the temperature. Therefore, if the container body enters the press at a different temperature due to a change in the temperature of the environment, the container body will expand or contract and will not fit into the guide that fixes the container body or will be eccentric with respect to the guide.

If the container body does not fit into the guide or is eccentric, press wobbling may occur, making it impossible to perform press operations with high precision.

The present invention has been made in consideration of these points,
It is an object of the present invention to provide a press cutting device capable of pressing a flange part of a plastic container body with high precision to obtain a high-precision container body.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a receiving section for mounting and receiving a plastic container body that has been thermoformed by sheet forming and sent through a supply pipe, and a receiving section that is disposed downstream of the receiving section and that is arranged downstream of the receiving section. A press device that presses a flange portion of a container body with the container body mounted and fixed in a guide, and a cutting device that is disposed downstream of the press device and cuts the outer periphery of the pressed flange portion, The press cut device is characterized in that a preheating device for maintaining the temperature of the container body at a predetermined temperature is provided upstream of the press device.

(Function) According to the present invention, the container body is heated in advance by the preheating device, maintained at a predetermined temperature, and then supplied to the press device, so that the shape of the container body is maintained substantially constant regardless of changes in the environmental temperature. be able to. Therefore, the container body can be reliably attached to the guide of the press device.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

1 to 4 are diagrams showing an embodiment of a press cutting apparatus according to the present invention. In FIG. 1, a press cutting device 10 is provided on a base 11 via a crank mechanism 12, and includes an intermediate bed 13 that reciprocates in the vertical direction. This intermediate bed 13 has three positions: an upper position, an intermediate position, and a lower position.

Further, an upper fixing base 15 is provided above the intermediate bed 13.

Further, as shown in FIG. 1, a male press die 21a is provided on the upper right side of the intermediate bed 13, and a female press die 21b is provided in the lower part of the upper fixing table 15 in correspondence with the male press die 21a. Press male die 21a and press female die 21
A press unit W21 is formed by b. On the other hand, a male cutting die 23a is provided on the upper left side of the intermediate bed 13, and a female cutting die 23b is provided at the lower part of the upper fixing base 15 in correspondence with the male cutting die 23a.
A cutting device 23 is formed by the cutting female mold 3a and the cutting female die 23b. Furthermore, a cooling stand 22 is provided at the center of the upper part of the intermediate bed 13.

In addition, a plastic container body 45 (
A guide 25, 26, 27 is provided which is mounted within the guide (Fig. j44). The guides 25, 26, 27 have a shape corresponding to the body 47 and bottom 48 of the container body 45, and are used to fix the container body 45 in a predetermined position.

Furthermore, as shown in FIG. 1, on the right side of the upper fixing base 15,
A supply pipe 28 for supplying the container body 45 is provided, and a receiving portion 52 for receiving the container body 45 is provided on the intermediate bed 13 in correspondence with the supply pipe 28. This supply pipe 28 supplies a container body 45 having a flange portion 46 molded from a plastic sheet by a general thermoforming method to the receiving portion 52. Further, the receiving portion 52 is supported on a supply table 30 disposed on the intermediate bed 13.

Further, on the left side of the upper fixing base 15, a discharge pipe 29 is provided which communicates with the cutting female die 23b and discharges the container body 45.

Between the intermediate bed 13 and the upper fixing base 15, the container body 45 is inserted into the press male die 21 of the press device 21 from the receiving part 52.
a1 cooling stand 22 and cutting male mold 2 of cutting device 23
A conveying device 17 for sequentially conveying the materials 3a and 3a in the horizontal direction is provided.

Note that the base 11, crank mechanism 12, and intermediate bed 13 are covered as a whole with a cover 16.

Further, as shown in FIGS. 1 and 2, the lower end of the supply pipe 28 is covered by a temperature control box 50.
The inside of the temperature control box 50 is always maintained at 40 to 60°C.

On the other hand, a hot air path 54 that opens at the upper end of the receiving section 52 and the supply table 30 is connected to the receiving section 52 and the supply table 30 .
It is arranged to penetrate through 0. This hot air path 54 is for feeding hot air of about 50° C. or higher into the container body 45 before it is installed in the receiving part 52 to heat the container body 45.

Next, the press device 21 will be explained with reference to FIG.

The press male die 21a of the press device 21 is attached to the intermediate bed 13.
A guide 25 is attached to the male die 21a via a press stand 36. The male press die 21a and the female press die 21b press the flange portion 46 of the container body 45 to make the flange portion 46 have a predetermined thickness, and each has a mold inside for heating the flange portion 46. Heaters 3B and 35 are provided. Also, inside the guide 25, a body 47 and a bottom 48 of the container body 45 are provided.
A cooling water flow path 34 is formed for cooling.

Next, the cutting device 23 will be explained with reference to FIG.

The male cutting die 23a of the cutting device 23 is connected to the intermediate bed 13.
A guide 27 is attached to the male cutting die 23a via a cutting table 41. Cut male die 23a
The cut female die 23b is the flange portion 4 of the container body 45.
6. The width of the flange portion 46 is set to a predetermined width by cutting the outer periphery of the flange portion 46.

In addition, the cut scum (not shown) of the cut flange portion 46 is pushed up on the outer periphery of the cutting table 41, and the cutting male mold 2 is
An ejector 40 is provided for separating it from 3a. Further, a holder 44 for holding a container body 46 is attached to the lower end of the inner surface of the cut female mold 23b facing upward.

Next, the operation of this embodiment having such a configuration will be explained.

First, a plastic sheet having a thickness necessary for forming a container is heated in advance by a general thermoforming method, and a container body 45 having a flange portion 46 is formed using a mold.

Subsequently, this container main body 45 is supplied to the receiving section 52 side via the supply pipe 28 and attached to the receiving section 52.

In this way, while the container body 45 is being supplied via the supply pipe 28, the container body 45 is placed in the box 5 of the supply pipe 28.
It will pass through the part covered by 0. In this case, since the inside of the temperature control box 50 is maintained at 40 to 60°C, for example, when the environmental temperature is low, the container body 45 is
It is supplied to the receiving part 52 side in a heated state by the temperature control box 50 maintained at 0 to 60°C. In addition, the receiving section 52
The container body 45 is further heated by hot air (approximately 50° C.) from a hot air path 54 that opens at the upper end of the receiving portion 52 before being attached to the container body 45 . Therefore, the container body 45 attached to the receiving part 52 is heated to a substantially constant temperature regardless of the surrounding environmental temperature.

Next, the intermediate bed 13 is placed at an intermediate position, and the container body 45 attached to the receiving portion 52 is gripped by a grip (not shown) of the conveying device 17.

Subsequently, the intermediate bed 13 is lowered to the lower position, and the container body 45 separated from the receiving part 52 is transported by the transport device 17 to above the male press die 21a.

Subsequently, the intermediate bed 13 is raised to the upper position through the intermediate position, and the guide 25 is installed inside the container body 45, and the container body 45 is fixed by this guide 25. Since the container main body 45 transported to the top of the male press mold 21H is heated to a predetermined temperature as described above, a substantially constant shape is maintained regardless of changes in the environmental temperature. Therefore, expansion or contraction of the container body 45 is prevented, and the container body 45 can be reliably mounted without being eccentric with respect to the guide 25.

Subsequently, the press female die 21b is slightly lowered by hydraulic pressure,
Press male die 21a and press female die 214. The flange portion 46 of the container body 45 is pressed between the
is adjusted to a predetermined thickness.

In this pressing process, the container body 45 is securely attached to the guide 25 and fixed in a predetermined position, so that the flange portion 46 is pressed with high precision between the male press die 21a and the female press die 21b. . That is,
Press shake, etc. that would occur if the container main body 45 or guide 25 is not securely attached does not occur.

Subsequently, the intermediate bed 13 is lowered to the intermediate position, and the container body 45 is gripped by the grip of the conveying device 17. Subsequently, the intermediate bed 13 is further lowered to a lower position, and the container body 45 is transported by the transport device 17 to a position above the cooling stand 22, and is mounted on the guide 26 on the cooling stand 22 to be cooled. Next, after the container body 45 is gripped by the grip of the conveying device 17, the intermediate bed 13 is lowered to the lower position, and
The container body 45 is cut by the conveying device 17 into the male die 23a.
transported to the top.

Subsequently, the intermediate bed 13 is raised from the intermediate position to the upper position. During this time, the container body 45 is mounted and fixed in the guide 27, and at the same time, the outer periphery of the flange portion 46 of the container body 45 is cut between the male cutting die 23a and the female cutting die 23b. is adjusted to a predetermined width.

In this way, the container main body 45 whose thickness and width of the flange portion 46 have been adjusted enters the cutting female mold 23b and is held by the holder 44. Then, this cut female mold 23b
The container body 45 that has entered the inside is newly cut into the female mold 23b.
The container body 45 that enters the container sequentially sends the container upward, and is discharged from the female cut mold 23b through the discharge pipe 29 to the outside.

In this way, according to this embodiment, the container body 45 can be maintained at a predetermined temperature by the temperature control box 50 of the supply pipe 28 and the hot air path 54 of the receiving section 52 before being supplied to the press device 21. , the container body 45 can be reliably attached to the guide 25 of the press device 21. Therefore, the flange portion can be pressed with high accuracy without causing press wobble or the like.

〔Effect of the invention〕

As explained above, according to the present invention, the plastic container body can be reliably attached to the guide of the press device, so the flange portion of the container body can be pressed with high accuracy without causing press wobbling. . Therefore, a highly accurate container with a metal lid can be obtained using a container body having a predetermined flange thickness.

10... Press cut device, 11... Base, 12
...Crank mechanism, 13...Intermediate base, 15...
・Upper fixing base, 17...Transport device, 21...Press device, 21a...Male press die, 21b...Female press die, 23...Cut device, 23a...Male cut die,
23b... Cut female mold, 45... Plastic container body, 46... Flange portion, 50... Temperature control box, 52... Receiving portion, 54... Warm air path.

Claims (1)

[Scope of Claims] 1. A receiving part for mounting and receiving a plastic container body thermoformed by sheet forming and sent through a supply pipe, and a flange part of the container body disposed downstream of this receiving part. a press device that presses the container body with the container body mounted and fixed in a guide, and a cutting device that is disposed downstream of the press device and cuts the outer periphery of the pressed flange portion, A press cutting device characterized in that a preheating device for maintaining the temperature of the container body at a predetermined temperature is provided on the side thereof. 2. The press cutting apparatus according to claim 1, wherein the preheating device is a temperature control box that covers the supply pipe. 3. The press cutting apparatus according to claim 1, wherein the preheating device is a hot air path that extends through the receiving section and sends hot air to the container body received in the receiving section.