JPH0347722A - Removing device for sprue - Google Patents

Abstract

PURPOSE:To obtain a device which reduces mechanical force, lengthens life of a cutter blade, can remove smoothly and efficiently a sprue and is suitable for treatment of an especially-large-sized molded product, by a method wherein a sprue pressing member is provided on a tool post of the cutter blade by positioning the same a little lower than an edge line of the cutter blade. CONSTITUTION:When a cutter comprised by fitting a cutter blade 5 to a tool post 5a by facing to a sprue 1a is slid by a driving cylinder 7, a pressing member 9 provided on the tool post 5a comes into contact with the lower part of the sprue 1a, to begin with. When the cutter is moved forward further, the sprue 1a is bent gradually toward an advancing direction of the cutter by the pressing member 9, turned into a bent state and pushing-down force is applied ahead to the sprue 1a. The edge of cutter blade 5 at this time arrives at the root of the sprue 1a for cutting. Since the root is cut off on the rear under a state where bending is given ahead to the sprue 1a like this, force to the edge is reduced as compared with the case where cutting is performed strongly with only the cutter blade without having the pressing member.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for cutting and removing a sprue portion of a molded article formed by injection molding means.

[Conventional technology]

In injection molding of thermoplastic synthetic resin products, the resin usually passes through sprues, runners, gates, etc. as a path to the mold cavity, but the resin solidified here is also attached to the molded product body. In order to obtain the final product, the part (hereinafter simply referred to as sprue) must be cut and removed from the main body after being removed from the mold. Usually, the cutting is done manually using nippers, knives, etc., but various methods and devices have been proposed for cutting the molded product when it is ejected from the mold or when the mold is opened.

The method of cutting with nippers or the like requires cooling and hardening time before cutting, resulting in poor manufacturing efficiency. The latter method, in which the molding is automatically performed when removed from the mold, shortens the molding cycle, but complicates the mold structure and equipment, and is not preferred, especially for large molded products such as pallets.

[Problem to be solved by the invention]

Due to this current situation, in the case of large molded products, the sprue is also large, so after the molded product is removed from the mold, it is fixed to a fixing device, and a cutter is used to cut the position corresponding to the sprue along the surface of the molded product. It is preferable to cut the sprue from the root by sliding the sprue. However, since the sprues are large, there are many sprues, and their bases are thick, a strong force is required to cut them, and the cutter blade is easily damaged, resulting in inconveniences such as the cut sprues flying off.

The purpose of the present invention is to solve these problems, reduce the mechanical force, extend the life of the cutter blade, and enable smooth and efficient sprue cutting, which is especially suitable for processing large molded products. The goal is to provide equipment.

[Means to solve the problem]

That is, in the present invention, a product molded by a normal injection molding device is fixed as it is on a fixing table, and a cutter is slid along the surface of the molded product at a position corresponding to the sprue part of the molded product to remove the sprue part. In the cutting/removal device, a sprue pressing member (9) is mounted on the mounting base (5a) of the cutter blade (5) and located below the cutting edge line of the cutter blade (5).
), the above objective has been achieved.

The fixing table for the molded product is usually configured to horizontally fix the molded product with the sprue side facing downward, and a cutter device is disposed on the bottom surface thereof. The cutter device has a cutter blade fixed to the top surface of a mounting base (5a) that moves horizontally along the bottom surface of the molded product, and its movement cuts the sprue protruding from the bottom surface of the molded product. There is.

In the present invention, a sprue pressing member (9) is provided on the stand (5a) on which the cutter blade is attached, and the position of the pressing member [9] is set between the center of the sprue and the base of the sprue before the cutter blade contacts the root of the sprue. The position should be in contact with the tip. That is, at the time when the cutting edge is in contact with the root of the sprue and the sprue is being cut, the sprue is bent in the direction in which the cutting edge advances, and it is important that the cutting is performed in this state. A plurality of the pressing members (9) may be provided corresponding to each sprue, but if the rod-shaped member is horizontally installed parallel to the line of the cutting edge of the cutter, one pressing member (9) can be provided for each sprue existing side by side. The rod-shaped bodies can be used at the same time. Note that it is not necessarily limited to a rod-shaped member, and a member of an appropriate shape may be provided protrudingly.

The cutter mounting base (5a) is attached to the cutter drive cylinder (
7), but it is preferable to install it vertically adjustable via a cylinder (8).

Note that large-sized molded products such as pallets, crates, containers, and containers are advantageous as injection molded products targeted by the present invention. Further, such molded products are commercialized in the form of bulk molded products, low foam molded products, high foam molded products, filler-containing molded products, etc. made from polyethylene, polypropylene, polystyrene, ABS resin, etc. as raw materials.

[work, use]

Since it is configured as above, as shown in FIG.
When the cutter consisting of the cutter blade (5) attached to the mounting base (5a) is slid by the driving cylinder (7), first the pressing member (
9) contacts the lower part of the sprue (la). When the cutter moves further forward, the pressing member (9) pushes the sprue (l
A) is gradually bent in the direction of movement of the cutter and becomes curved, and a force is applied to push it forward. At this time, the cutting edge of the cutter blade (5) reaches the root of the sprue (la), and then it is cut. In this way, the root is cut from the rear while the sprue is deflected forward, so the force on the cutting edge is significantly reduced compared to when cutting forcefully with only the cutter blade without a pressing member. At the same time, the impact at the time of cutting is alleviated and the cutting and separation occur naturally, thereby preventing the cut sprue from scattering violently.

[Example] A specific example will be described with reference to the drawings. FIG. 1 is a side view showing the main parts of the apparatus of the present invention. 1 is an injection molded product, in this case a pallet, la is its sprue, 2 is a pedestal for fixing the molded product, and the molded product l placed on this is held by a presser 3 and a presser plate 4. Fixed from the side and above. 5 is fixed by a cutter blade to the upper surface of a mounting base 5a, and the mounting base 5a is connected to a mounting portion 6 of a cylinder 7 which is driven horizontally to cut the sprue 1a.

The cutter mounting table 5a and the mounting portion 6 may be connected by ordinary fixing means, but if they are connected via a cylinder 8 as shown in the figure, it is easy to adjust the proximity to the molded product 1 above. . Reference numeral 9 denotes a sprue suppressing member provided on the cutter blade mounting base 5a, and is provided so as to be in front of the cutting edge of the cutter blade 5 and to come into contact with the longitudinal center or tip of the sprue la. In this example, as shown in the front view in FIG. 2, the rod-shaped body is horizontally installed parallel to the cutting edge of the cutter blade. In fixing this pressing member 9, it is preferable to allow the position to be changed and adjusted each time depending on the size of the sprue. For example, it is preferable to be able to adjust up and down in FIG. 2 and back and forth in FIG. 1. IO is a cooling air blowing pipe, which is effective for cooling when maintaining the cutter blade in close contact with the cut end on the main body side of the molded product after cutting, especially when applied to sprue cutting of a foam molded product.

〔Effect of the invention〕

According to the present invention, since the sprue is cut from the rear while being deflected forward, the mechanical force during cutting is reduced, the life of the cutter blade is extended, and the impact during cutting is reduced. Since the sprue can be cut smoothly without scattering the cut sprue, it is extremely useful especially for pallets and other human-shaped molded products.

[Brief explanation of drawings]

FIG. 1 is a side view of main parts in an embodiment of the present invention, and FIG.
The figure is a front view of the cutter blade attachment section. ■... Injection molded product 1a... Sprue part of the molded product 2... Molded product fixing pedestal 3.4... Presser foot
Tool 5...Cutter blade 7...Cutter drive cylinder 9...Sprue pressing member 10...Cooling air blowing pipe

Claims (1)

[Claims] A cutter blade (5
) A sprue cutting device for an injection molded product, characterized in that a sprue pressing member (9) is provided on the mounting base (5a) of the cutter blade (5) at a position slightly forward and lower than the cutting edge line of the cutter blade (5).