JPS6233617A - Detection of discharge of molding - Google Patents

Abstract

PURPOSE:To prevent damage of mold or molding machine due to faulty dis charge of molding by a method wherein the detecting condition of molding before discharging operation and the non-detecting condition of the same after discharging operation are detected by an optical sensor. CONSTITUTION:The optical sensor 1, whose detecting point is focussed to the position of a molding adhered to the mold 18, detects whether the molding is discharged out of the mold 18 or not especially upon opening the mold. Dis charge of molding is detected by satisfying two conditions that the optical sensor 1 is in the detecting condition of the molding before starting discharging operation and that the same sensor 1 is in the non-detecting condition of the molding after funishing the discharging operation. According to this method, the molding is confirmed that it is adhered to the side of a core mold 15. There after, molding discharging operation such as projecting operation or the like is effected and after finishing this operation, it is detected again whether the molding is adhered to the mold 18 or not.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a molded article discharge detection method for optically detecting whether or not a molded article has been discharged from a mold in a molding machine.

(Prior Art) Conventionally, in a molding machine such as an injection molding machine or a die-casting machine, the following methods are known as methods for optically detecting whether or not a molded product has been ejected from an opened mold. It is being

(a) An optical sensor is attached to the chute placed below the mold, and when the molded product ejected from the mold falls on the chute, it crosses the light of the optical sensor and is detected. .

(b) An optical sensor is arranged so that the detection point matches the position of the molded product attached to the mold, and this allows light to be emitted directly to the part where the molded product is attached after the molded product ejection operation is completed, and prevents residual molded products from remaining. Detected by whether or not there is a blockage of light.

(c) While projecting light into the mold cavity, the reflected light is detected by an optical sensor, and detection is performed based on the difference in the amount of reflected light.

(Problems to be Solved by the Invention) However, the methods (a) to (C) described above all have the following problems.

First, in the method (a), if a part of the molded product crosses the light beam of the sensor, for example, an electric contact or the like is actuated to detect that the molded product has been ejected. therefore,
This method has no problem when molding is a single product, but when molding multiple products, even if some molded products remain in the mold, the process will proceed to the next cycle, causing damage to the mold and molding machine. Cause.

On the other hand, the method (b) is usually carried out by providing a phototube or the like (optical sensor) in the core type. However, if the molded product remains in the cavity mold (fixed mold), there will be no molded product in the core mold (movable mold) side, and the cycle will proceed to the next cycle. This causes problems such as double pressing, which also causes damage to the mold, etc., as in (a). Furthermore, in the case of multiple tubes, multiple sets of phototubes are required, making it difficult to use for molded small parts due to installation space and other considerations.

On the other hand, in method (C), the amount of reflected light to be detected varies depending on lighting conditions around the molding machine, dirt on the mold surface, etc., and accurate detection cannot be performed. For this reason, it becomes difficult to manage the surrounding area, and a highly sensitive optical sensor is required to detect subtle changes in the amount of light, and it is difficult to detect molded products such as small parts.

As described above, all of the methods (a) to (c) are insufficient in terms of reliable discharge detection, and also have the problem of limiting the size, type, etc. of molded products that can be used.

(Means for Solving the Problems) The present invention solves the above-mentioned conventional problems by using the following molded article discharge detection method.

In other words, the molded product discharge detection method according to the present invention detects whether or not the molded product has been discharged from the mold, especially when the mold is opened, using an optical sensor whose detection point is aligned with the position of the molded product attached to the mold. In the molded product discharge detection method, the optical sensor 1 is in a detection state before the molded product discharge operation starts, and the optical sensor 1 is in a detection state after the molded product discharge operation is finished.
The present invention is characterized in that it is detected that the molded product has been ejected by satisfying both of the conditions that the molded product is in an undetected state.

(effect) Next, the operation of the present invention will be explained.

In the molded product discharge detection method according to the present invention, it is first detected whether or not a molded product is attached to the mold.

In other words, confirm that the molded product is attached to the core mold side. After this, a molded product ejecting operation such as an ejection operation is performed, and after this operation is completed, it is again detected whether or not a molded product is attached to the mold, and it is confirmed that no molded product is detected, that is, there is no molded product. to detect that the molded product has been ejected.

(Example) Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

First, in order to clarify the present invention, the schematic structure of an injection molding machine will be explained with reference to FIG. The figure is a cross-sectional plan view of the mold and its surroundings in an injection molding machine (1-1 in Figure 2).
(including the I-line cross section).

The injection molding machine M is equipped with an injection device 10, and further includes an injection device 10.
includes an injection cylinder tta and an injection nozzle llb provided at the tip of the cylinder 11a.

For example, in the case of an in-line screw type injection molding IIM, a screw is installed inside the cylinder lla, and the injection nozzle lla is
Inject the molding material from b.

On the other hand, a mold device 12 is provided in front of the injection device 10.

This device 12 includes a fixed mold (cavity type) 13 disposed to be plugged into the injection nozzle llb.
is fixed to the fixed platen 14.

A movable mold (core mold) 15 is arranged opposite to the fixed mold 13,
This movable mold 15 is connected to the fixed mold 13 by an integrated movable platen 16.
It moves forward and backward on the tie bar 17.17. Fixed type 13
and the movable mold 15 constitute a mold 18, which includes a cavity 18a,
A known mold having a runner 18b, a sprue 18c, etc. is constructed. Note that the symbol W indicates a two-cavity molded product.

Further, the interior space of the movable mold 15 is provided with a protruding bin 19 facing the cavity 18a, and this bin 19 has an integral protruding plate 20 at its rear end.

Additionally, in FIG. 1, reference numeral 21 denotes a protruding cylinder provided within the movable platen 16, and is provided with a protruding piston 22 for moving the protruding plate 20 forward.

23 is a return spring inserted into the protruding bottle 19;
Reference numeral 4 denotes a drive ram that moves the movable platen 16 forward and backward to close and open the mold.

Next, an example of a detection device suitable for carrying out the discharge detection method according to the present invention will be explained with reference to FIG. The figure is the first
It is a perspective view in the direction of arrow ■ in the figure. In addition, in FIG. 2, the same parts as in FIG. 1 are given the same reference numerals to clarify the structure.

First, blocks 2.3 are fixedly installed on both sides of the movable mold 15 so as not to hinder mold clamping. Each block 2.3 has through holes 4 and 4 corresponding to the product parts Wl and W2 of the molded product W.
...to penetrate. Through hole 4... is for each product part W1, W2
are formed on a straight line passing through. In the exemplary embodiment, therefore, each block 2.3 is provided with two through holes 4.

On the other hand, on the upper side of the movable platen 16, an optical sensor 1 is disposed, which includes one light emitter 5 containing a light emitting element and one light receiver 6 containing a light receiving element.

One end of the optical fiber cord 7 is connected to the light emitter 5, and the other end is branched into two cord parts and inserted into the through hole 4 of the block 2.
．． Insert and fix into 4 respectively. Further, one end of an optical fiber cord 8 is similarly connected to the light receiver 6, and the other end is made up of a pair of cord parts each inserted and fixed into the through hole 4.4 of the block 3.

With this configuration, the irradiated light from the light emitter 5 passes through the optical fiber cord 7 and is projected from the tip of the block 2. The light beam is blocked when the molded product W is not discharged, but when it is discharged, it is received at the tip of the optical fiber cord 7 in the block 3, further passes through the cord 7, and is received by the light receiver 6.

Note that the light receiver 6 is connected to the product section Wl before the ejection operation starts.
, if even one of W2 is missing, this will be detected, and after the discharge operation is complete, 1 (11i1 will not be detected if there is not enough remaining). Two sensitivities are switched depending on the process and used. In this case, the light emission is used instead of the sensitivity. You may also change the light intensity of the device.

Next, the molded article discharge detection method according to the present invention will be explained together with the overall operation.

(a) First, a metering process and an injection process are performed in the injection device, whereby the mold 18 is filled with material. The mold 18 is opened after a predetermined cooling time.

(b) Next, the light emitter 5 is turned on. Turn on this light emitter 5
If the light receiver 6 does not receive light even after a certain period of time has passed since the ejection, that is, if the molded product W is properly attached to the movable mold 15, the light emitter 5 is turned off and the process moves to the next ejection process. .

On the other hand, if the light receiver 6 receives light due to the light emitter 5 being turned on, there is a possibility that a part of the molded product W remains in the fixed mold 13, so the mold remains open without proceeding to the ejection process. Issue a warning, etc. Also, the light emitter 5 is turned off to interrupt the cycle. Then, after the operator manually removes the molded product, automatic operation is restarted from the beginning.

(C) On the other hand, when proceeding to the ejection process (ejection operation), the ejection cylinder 21 is operated to move the ejection pin 19 forward. As a result, the molded product W is removed from the movable mold 15. After ejection, the ejection cylinder 21 is operated in reverse to move the ejection piston 22 backward. As a result, the ejecting pin 19 is also returned to its original position by the spring 23.

The ejection operation in the above-described ejection process is performed by selecting and setting the number of times as appropriate depending on the shape of the molded product and the like.

(d) When such ejection operation is completed, the light emitter 5 is turned on again. If the light receiver 6 receives light due to the light emitter 5 being turned on, this means that the molded product W is being normally ejected from the movable mold 15, so the light emitter 5 is turned off. This completes one cycle process.

On the other hand, if the light emitter 5 is ONL and the light receiver 6 does not receive light even after a certain period of time, there is a possibility that the molded product (or a part of it) remains in the mold (movable mold). The light emitter 5 is turned off and an alarm is issued to interrupt the cycle. Then, the operator manually removes the molded product W and restarts automatic operation from the beginning.

Molding and discharge detection are performed by continuously repeating steps (a) to (d) in the above embodiments.

In addition, by using an optical fiber cord as in the example, it is possible to set a detection optical path for each pitch even for small molded products (products), and the emitter and receiver can be set regardless of the number of molded products. One optical sensor including the one and the accompanying amplifier etc. are sufficient.

This allows for significant cost reduction and miniaturization.

Although the embodiments have been described in detail above, the present invention is not limited to these embodiments.

For example, the optical sensor uses an active method, but CC
A passive method using D or the like may be used.

Alternatively, the phototube may be installed directly on the side of the mold. Furthermore, the detection location of the optical sensor is not limited to the product section, but may be similarly installed at the sprue section, runner section, etc. Other changes may be made in the detailed configuration, procedures, etc., without departing from the spirit of the present invention.

(Effects of the Invention) As described above, the molded product ejection detection method according to the present invention detects whether or not the molded product has been ejected from the mold when the mold is opened by aligning the detection point with the position of the molded product attached to the mold.・Intelligence law requires that the optical sensor is in a detection state before the molded product is ejected, and that the optical sensor is in a non-detection state after the molded product is ejected. Since it is detected that a molded product has been ejected by satisfying both conditions, it is possible to easily and reliably detect whether a molded product is attached to an incorrect position or if it has not been completely ejected. This can be detected and can prevent damage to molds and molding machines due to improper ejection of molded products.

Furthermore, since the conventional device can be used as is, the structure is simple and can be implemented at low cost.

Furthermore, by distributing detection points to multiple locations using optical fiber codes according to a preferred embodiment, detection for each product can be ensured.
Moreover, it can be easily detected, and moreover, it can be made smaller, more compact, and lower in cost.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional plan view of a mold and its surroundings in an injection molding machine (including a cross section taken along the line 1-I in FIG. 2), and FIG. 2 is a perspective view in the direction of arrow 1 in FIG. In the drawings, 1...optical sensor, 2.3...block, 5...light emitter, 6...light receiver, 7.8...optical fiber code.

Claims (1)

[Claims] 1. A molded product ejection detection method that detects whether or not the molded product has been ejected from the mold when the mold is opened using an optical sensor whose detection point is aligned with the position of the molded product attached to the mold. A method for detecting discharge of a molded article, which detects discharge of a molded article by satisfying the following conditions (a) and (b). (a) the optical sensor is in a detection state before the molded product discharge operation starts; (b) the optical sensor is in a non-detection state after the molded product discharge operation is finished;