JPS6135911A - Finishing method of transparent of translucent plastic molded part and device therefor - Google Patents

Abstract

PURPOSE:To finish a molded part quickly and surely and at the same time prevent whitening and cracks from developing by a method wherein a cutter equipped with a filing part is used at the cutting-off of a gate mark. CONSTITUTION:A transparent or translucent plastic molded part with a gate mark 1 thereon is taken out of a mold and stationarily supported by means of a chucking mechanism 3. A cutter 4 is advanced toward the gate mark of the stationarily supported part 2 vertically or laterally in order to cut off the gate mark. No vibration of the cutter is always necessary during the advance of the cutter 4. Whitening and cracks can be prevented from developing in the molded part, because the molded part is finished by using the chucking mechanism 3 to stationarily support the molded part and the cutter blade and filing part 42 to cut off the gate mark and to file the surface, from which the gate mark is cut off.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for finishing gate marks on transparent or translucent plastic molded products such as acrylic resin, and an apparatus used for finishing.

[Conventional technology]

In general injection molding, as shown in Figure 5, the hopper 1
A raw material is supplied from 00, heated and melted in a heating chamber 102 heated by an electric heater 101, and then transferred to a piston 1.
03, the material is rapidly pushed into a mold 105 through a nozzle 104, and is solidified and molded. Then, in the mold 105, the molten resin is transferred to the cavity 106.
Since the part of the gate 107 that is injected into the molded product 200 remains (see FIG. 6), this part is sheared as a secondary process.

[Tm Zhao's point to be solved] In transparent or translucent plastic molded products, whitening and cracking occur due to shearing of the gate marks, which not only causes problems in appearance, but also causes problems in the sheared areas due to the transparent or translucent nature. However, the product value of the molded product was reduced due to glare due to changes in the refraction of light.

Even if an opaque plastic molded product has no problem in appearance, a transparent acrylic molded product or the like has a lens effect, so sheared areas are noticeable and the appearance is poor. Secondary processing of plastic molded products includes, in addition to shearing by push-cutting, cutting with a saw, marking and folding from there, drilling holes with a drill, and processing with a milling cutter. However, shearing and cutting are commonly used to remove gate marks. Then, in order to ensure uniform transparency and uniformity of light refraction, other parts of the gate trace, including the sheared part, were also cut with a milling machine and discarded. Moreover, there was also a waste of materials.

[Means for solving the same problem]

When removing gate marks, the removal marks do not adversely affect transparent or opaque plastic molded products.
Moreover, this invention was made in order to simplify the operation after taking out the molded product and to eliminate waste of materials.To achieve this purpose, the following structure was adopted. That is, the finishing method of this invention takes out the molded product with the gate marks from the mold,
A process of holding the molded product stationary, a process of cutting the gate mark with a cutter having a blade at the tip and a file part in the middle, and a process of vibrating the cutter in parallel with and in contact with the gate mark removal surface. The method includes a step of polishing with a file section. The finishing device of the present invention also includes a chuck mechanism for holding still the molded product with the gate mark removed from the mold from a direction perpendicular to the gate mark and in the vicinity of the gate mark; A vibration generator is equipped with a cutter equipped with a blade and a file portion in the middle, and this cutter advances from a horizontal or vertical surface with respect to the gate mark, and the vibration generator is activated or advanced. The above purpose is achieved by cutting off the gate marks with the blade at the tip and polishing the surface from which the gate marks have been removed using a file.

〔Example〕

Preferred embodiments of the present invention will be described below with reference to the drawings.

The transparent or translucent plastic molded product 2 with the gate mark 1 remaining is taken out from the mold, and the molded product 2 is placed in the chuck mechanism 3.
Grasp it and hold it still.

In this process, the molded product 2 taken out from the mold is moved to a predetermined location using a transfer device, a robot arm, etc., and chucked at the location perpendicular to the gate mark 1 and in the vicinity of the gate mark 1. The molded product 2 is held stationary by being clamped by a mechanism 3, such as a hydraulic cylinder. Alternatively, the molded product 2 may be placed on the table so that the gate mark 1 protrudes from the edge of the work table, and the molded product 2 may be pressed down from above.

If the molded product 2 is held stationary in this way.

A cutter 4 is advanced toward the gate mark 1 from either the upper or lower direction or from the side to cut the gate mark 1. It does not matter whether the cutter 4 vibrates or not when it advances. That is, the blade 41 of the cutter 4
The gate mark 1 may be cut by either a pushing method or a method of cutting while vibrating. In addition to the blade 41, this cutter 4 is equipped with a file part 42 in the middle part, and the surface of the gate mark 1 after being cut is filed with this file part 42. At this time, the cutter 4 is vibrated by the vibration generator 5. As the vibration generator 5, a cutter 4 is attached to a piston 51 of various cylinders via a fitting 52, and the cutter 4 is moved by the movement of the piston 51 of this cylinder.
It is also possible to apply vibration to the motor (see Fig. 3), and the rotation of the motor 53 is converted into reciprocating motion by the conversion mechanism 54.
This can also be achieved by reciprocating the attachment 52 of the cutter 4 (see FIG. 4). The vibration generator 5 in FIG. 4 is
The same principle may be used to move the needle of a sewing machine.

Furthermore, the cutter 4 can be reciprocated or vibrated using an electromagnet.

It is desirable that this vibration be at high speed.

In this invention, the chuck 1ilIf13 for holding the molded product 2 still, the gate trace 1 is cut, and the gate trace 1 is cut.
A blade 41 and a file part 42 for filing the removal surface of
A transparent or translucent plastic molded product can be finished by employing only the vibration generator 115 for applying vibration to the cutter 4 and the following process. That is, after the step of holding the molded product 2 stationary, the gate mark 1 is cut with a cutter 4 having a blade 41 at the tip and a file part 42 in the middle part, and the gate mark 1 is brought into contact with the removed surface of the gate mark 1. It is sufficient to vibrate the cutter 4 in parallel and perform ms using the file portion 42.

〔effect〕

As explained above, according to the finishing method of the present invention,
By using a cutter with a file when cutting gate marks, you can finish quickly and reliably, and
Prevents whitening and cracking. Further, according to the finishing device of the present invention, it is possible to easily cut and polish gate marks using simple equipment. For transparent or translucent plastic molded products, removing gate marks and subsequent polishing also prevents the occurrence of unnatural appearances due to light transmission and refraction.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a molded product with gate marks taken out from a mold and held still, Figure 2 is an explanatory diagram of a state in which the cutter is vibrated from the state shown in Figure 1, and Figure 3 is an explanatory diagram of a vibration generator. FIG. 4 is a schematic diagram showing the other side of the vibration generator, FIG. 5 is an explanatory diagram of a general injection molding machine, and FIG. 6 is an explanatory diagram of the gate section. 1... Gate trace, 2... Molded product, 3... Chuck L, 4... Cutter, 5... Vibration generator, 41...Blade, 42...File part. Applicant NEC Home Electronics Co., Ltd. Agent Patent Attorney Masu 1) Takeo Figure 5 Figure 6 Procedural Amendment (Hakuwa August 1982 298 1, Indication of Case 1982 Patent Application No. 160112 2, Name of the invention: Finishing method and device for transparent or translucent plastic molded products 3; Relationship with the amended person's case Patent applicant address: Nippon Denki, 1-8-17 Umeda, Kita-ku, Osaka-shi, Osaka Name ( 193) NEC Home Electronics Co., Ltd. 4, Agent 104 Address 3N Ginza 2-chome, Chuo-ku, Tokyo @ Ginza Ooi Building 3N Telephone 03 (545) 2818 Name (7882) Patent attorney Masu 1)
Takeo 5, Subject of amendment (1) Column indicating "patent application pursuant to the proviso to Article 38 of the Patent Act" in the application (2) "Number of inventions stated in the scope of claims" in the application
Column 6, Contents of amendment (1) Enter the statement "A patent application pursuant to the proviso to Article 38 of the Patent Act" in the application form. (2) Provide a column for ``Number of inventions stated in the scope of claims'' between the ``title of the invention'' and ``inventor'' in the application, and enter ``2'' in this column.

Claims (1)

[Claims] 1. A step of taking out the molded product with the gate marks left from the mold and holding the molded product stationary, and cutting the gate marks with a cutter having a blade at the tip and a file part in the middle part. A method for finishing a transparent or semi-transparent plastic molded product, comprising the steps of: vibrating a cutter in contact with and parallel to the surface from which gate marks are removed and polishing with a file portion of the cutter. 2. A chuck mechanism for holding the molded product with a gate mark removed from the mold stationary from a direction perpendicular to the gate mark and in the vicinity of the gate mark, and a blade at the tip and a file in the middle. The cutter advances from a horizontal or vertical surface to the gate mark, and as the vibration generator operates or advances, the blade at the tip of the cutter advances. A finishing device for a transparent or translucent plastic molded product, which is characterized by cutting gate marks and polishing the surface from which gate marks have been removed using a file.