JPS644502Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a plastic molding apparatus, and more specifically, to a mechanism for detecting whether or not a molded product is discharged from a die.

(Prior Art) Generally, a plastic molding apparatus is configured to repeat a series of molding operations in accordance with a discharge detection signal that detects whether or not a molded product is discharged from a die.

FIG. 3 is an explanatory diagram showing an example of the configuration of essential parts of such an apparatus. In FIG. 3, reference numeral 1 denotes an injection section through which plastic, which is a raw material, is injected, and the injection port is arranged so as to open into a mold provided in a die 2. The die 2 is arranged so as to be movable back and forth with respect to the injection section 1. 3 is die 2
This is an extrusion mechanism for extruding the molded product 4 from the mold, and is movably inserted into a part of the die 2 so as to push out the molded product 4 when the die 2 retreats to a predetermined position. Reference numeral 5 denotes a molded product take-out mechanism, which is configured to grasp a part of the molded product 4 protruding from the die 2 and take it out from the mold. Such a take-out mechanism 5 includes a holder 51 that grips a part of the molded product 4, a cylinder 52 that uses the holder 51 as the die 2 and moves it in the vertical direction, and one end of the cylinder 52 that swings along the moving direction of the die 2. It is composed of a cylinder 53 and the like. 6
is a discharge part of the molded product 4 discharged from the die 2. A part of the discharge section 6 is provided with means for generating a signal for detecting that the molded product 4 is discharged from the die 2. Examples of such discharge detection signal generating means include a door switch configured so that the contacts of the switch 8 open and close in conjunction with the door 7 which is opened and closed when the molded product 4 passes, and a door switch that responds when the molded product 4 passes. An optical sensor that measures the weight of the discharged molded product 4, a sensor that measures the weight of the discharged molded product 4, and the like are used. Then, it is confirmed that the molded product 4 has been discharged from the die 2 in accordance with the discharge detection signal obtained in this manner, and the series of molding operations is repeated. That is,
By outputting the discharge detection signal from such discharge detection signal generating means, it is determined that no molded product 4 remains in the die 2, and the next molding operation is performed, and if the discharge detection signal is not output, the die It is determined that the molded product 4 remains in the mold 2, an alarm signal is output, and the molding operation is stopped.

(Problem that the invention aims to solve) However, when a door switch is used as a means for generating an emission detection signal, the door may not be able to be opened if the molded product is light. If the item jumps over the position of the optical sensor, it cannot be detected, and if a weight sensor is used, there is a drawback that detection takes time. As a result, the molding apparatus may be treated as abnormal even though it is operating normally, or the detection time becomes longer, which lengthens the operation cycle of the entire apparatus, which is undesirable.

The present invention solves these drawbacks, and its purpose is to provide a means that can reliably detect whether or not a molded product is ejected from a die in a short period of time with a relatively simple configuration. An object of the present invention is to provide a plastic molding device.

(Means for Solving the Problems) The present invention that achieves the above object is a plastic molding device configured to repeat a series of molding operations in accordance with a discharge detection signal that detects discharge of a molded product from a die. The apparatus is characterized in that a vibration detection sensor is provided as the discharge detection signal generating means to detect vibrations generated when the discharged molded product falls and collides with the discharge section and converts it into an electrical signal.

(Example) Hereinafter, it will be explained in detail using the drawings.

FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention, and the same parts as in FIG. 3 are given the same reference numerals. In FIG. 1, 9 is a vibration detection sensor attached to a part of the discharge section 6, which detects vibrations generated when the molded product 4 discharged from the die 2 falls into the discharge section 6 and collides with it. The signal is then converted into an electrical signal. As such a sensor 9, for example, a microphone is used.

In such a configuration, when the molded product 4 is ejected from the die 2 by the extrusion mechanism 3 or the ejection mechanism 5 and falls into the ejection section 6 and collides with it, the vibration detection sensor 9
detects the vibrations and converts them into electrical signals. The molding device then repeats a series of molding operations in accordance with this electrical signal.

FIG. 2 is a time chart showing an example of such an operation, and shows the operation when the device is set to automatic operation mode. In Figure 2, (a)
shows the contact signal of the automatic operation mode setting switch, (b) shows the contact signal of the switch placed at the backward limit position of die 2, and (c) shows the contact signal of the switch placed at the forward limit position of die 2. (d) shows the contact signal of the safety switch of the device, (e) shows the drive signal of the vertical cylinder 52 in the extraction mechanism 5, and (f) shows the drive signal of the swing cylinder 5 in the extraction mechanism 5.
(g) shows the vibration detection timing of the sensor 9, (h) shows the timing at which the detection signal of the sensor 9 is processed, (i) shows the timing at which molding is performed, ( j) shows the contact signal of the switch placed at the initial position of the take-out mechanism 5.

First, when the automatic operation mode is set at time _t1 , the mode switch is held on until the mode is switched. Then, at time _t2 , the safety switch is turned on, and at the same time the die 2 starts moving forward toward the injection section 1, and the retreat position switch is turned off. When the die 2 reaches the forward limit position at time _t3 , the forward position switch is turned on, and molding is performed until time _t4 when the die 2 starts moving backward. When the die 2 starts to move backward, the forward position switch is turned off, and when it returns to the backward limit position at time _t5 , the backward position switch is turned on again. At the same time as the die 2 returns to the retraction limit position, the vertical cylinder 52 begins to descend from the initial position, and the initial position switch is turned off. At time _t6 when the vertical cylinder 52 has descended to a predetermined position, the swing cylinder 53 is also driven. Each of these cylinders 52, 53 is driven for a certain period of time until time _t7 . When the molded product 4 is taken out from the die 2 in this way and falls into the discharge section 6 and collides with it, the sensor 9
detects the vibration that occurs at t ₈ during the collision. and,
This detection signal is processed at time _t9 when the take-out mechanism 5 returns to the initial position, and after confirming that the molded product 4 has been discharged from the die 2, the next molding operation is started.

As a result, if a detection signal is not output from the sensor 9, the operation of the device will be stopped.
It is possible to prevent damage to the die due to improper ejection of the molded product.

Note that if the molded product 4 is reliably extruded by the extrusion mechanism 3, the sequence of the extraction mechanism 5 may be omitted.

Further, with this configuration, the detection sensitivity can be set freely, and the presence or absence of discharge of the molded product can be reliably detected. According to experiments, even when a molded product falls onto a rubber plate, it can be completely detected.

Further, the sensor for detecting vibration is not limited to a microphone, and other vibration sensors may be used.

(Effects of the invention) As explained above, according to the invention, a plastic molding apparatus is provided with a means that can reliably detect whether or not a molded product is ejected from a die in a short period of time with a relatively simple configuration. can be realized, and the practical effect is great.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the main part of an embodiment of the present invention, Fig. 2 is a time chart for explaining the operation of Fig. 1, and Fig. 3 is an explanatory diagram of the main part of the conventional device. . DESCRIPTION OF SYMBOLS 1... Injection part, 2... Die, 3... Extrusion mechanism, 4... Molded product, 5... Takeout mechanism, 6... Discharge part, 9... Vibration detection sensor.

Claims (1)

[Scope of utility model registration request] In a plastic molding device configured to repeat a series of molding operations in accordance with a discharge detection signal that detects the discharge of a molded product from a die, the discharge detection signal generation means is a system in which the discharged molded product falls into the discharge section. 1. A plastic molding device characterized by being provided with a vibration detection sensor that detects vibrations generated by collision between objects and converts them into electrical signals.