JPS5839888Y2 - Transfer molding machine with plunger operation abnormality alarm - Google Patents

Description

[Detailed description of the invention] The present invention relates to a transfer molding machine with a plunger operation abnormality alarm, which is designed to issue an abnormality alarm related to the molding machine in order to prevent molding defects in transfer molding. The present invention relates to a transfer molding machine with a device.

First, a conventional transfer molding machine and its molding method will be explained with reference to FIG.

Figure 1 is a sectional view of the main parts of a conventional transfer molding machine.
The molding method is also shown, and 1 is a franchiser, 2 is a cylinder for driving a plunger, 3 is a sleeve, 4 is a resin, 5 is an upper mold related to the mold, 6 is a lower mold, and 7 8 indicates a cavity, and 8 indicates a range burr.

In particular, during molding, the plunger 1 is moved down along the sleeve 3 by the action of the cylinder 2, and pushes the range 4 into the cavity 7 formed by the upper mold 5 and the lower mold 6. The previous one is what you get.

At this time, the resin 4 may enter the small gap between the plunger 1 and the sleeve 3, causing resin burrs 8.

Generally speaking, this resin burr rarely occurs when the plunger or sleeve is new, but
As the plunger and sleeve are used, they wear out and the gap widens, causing the resin burr to gradually thicken and appear with every shot.

If the next molding is performed with the thickened resin burr left, the resistance when the plunger passes through the sleeve will increase.
This causes problems such as insufficient pressure being transmitted to the resin, such as the resin not filling the cavity.

Therefore, if the resin burr exceeds a certain limit, it must be removed.

On the other hand, when the wear of the plunger and sleeve becomes very large (that is, when the gap becomes very large), if the resin burr is completely removed, resin will leak upward from the gap and the required amount of resin will increase. is not filled into the mold, which also causes defects.

In this case, the plunger or sleeve needs to be replaced.

However, if a resin burr of an appropriate thickness is attached, resin leakage may be eliminated even in such a case, so from experience molding operators should leave a resin burr of an appropriate thickness and remove the plunger. Somehow, the molding continues without replacing it.

However, in such a state, the resistance between the plunger and the sleeve increases, which is likely to lead to molding defects.

In particular, when unskilled workers perform molding work, they need to know how large the resistance between the plunger and sleeve should be before removing the resin burrs, and how much should the wear of the plunger and sleeve become large? This had the disadvantage that it was not possible to determine whether a product needed to be replaced or not, resulting in a large number of defective products.

The present invention eliminates the drawbacks of the prior art as described above, detects abnormalities in the plunger or operating status in transfer molding, and notifies the operator of the abnormality, thereby preventing the occurrence of defects. The object of the present invention is to provide a transfer molding machine with a plunger operation abnormality alarm as described above.

The feature of this invention is that the plunger is passed through the snob once before molding, and the magnitude of the sliding resistance at that time is measured using the oil pressure of the plunger's cylinder. The system is equipped with a device that issues an alarm when the transfer molding machine is equipped with a hydraulic pressure sensor that detects the hydraulic pressure of the plunger drive cylinder, and a device that issues an alarm when the plunger is inserted into the sleeve of the mold with the mold open. A plunger operation device equipped with a pressure setting/comparison device that compares the oil pressure detected by the oil pressure sensor when lowering the oil pressure with a preset oil pressure, and an alarm device that issues an alarm when the detected oil pressure becomes larger than the set oil pressure. The present invention consists in configuring a transfer molding machine with an abnormality alarm.

Next, one embodiment of the present invention will be described with reference to FIG.

Here, FIG. 2 is a partially cross-sectional schematic diagram of a 1-haler spacing molding machine equipped with a plunger operation abnormality alarm according to an embodiment of the present invention.

In the figure, parts with the same symbols as in Fig. 1 indicate equivalent parts, 9 is a hydraulic piping, 10 is an oil pressure sensor, 11 is a pressure setting/comparator related to the pressure setting/comparison device, and 12 is the oil pressure of the molding machine. 13 is an electric circuit for operation control; 13 is an inspection switch;
4 is an alarm buzzer related to the alarm device.

That is, in this embodiment, the hydraulic pressure sensor 10 is attached to the hydraulic pipe 9 of the cylinder 2.
The output of 0 is the pressure setting/comparator 11 (hereinafter referred to as comparator 11).

), and this comparator 11 is connected to an electric circuit 12 (hereinafter referred to as electric circuit 12) for controlling the hydraulic operation of the molding machine.

) is connected. The electric circuit 12 and the comparator 11 are connected to an inspection switch 13, and when the inspection switch 13 is turned on, the upper mold 5 and the lower mold 6 open, and the plunger 1 moves inside the sleeve 3. After descending until the thick part at the tip of the sleeve 1 passes through the sleeve 3, it rises to the home position.

Note that FIG. 2 is a diagram showing the plunger 1 in the process of being lowered.

At this time, the comparator 11 detects the pressure P (hereinafter referred to as P) detected by the oil pressure sensor 10 when the plunger 1 descends.

) and a preset pressure po (hereinafter referred to as po).

), and when P≦PO, an alarm buzzer 14 is sounded.

Next, the actual operation will be explained.

After the shaping is completed, when the inspection switch 13 is turned on, the plunger 1 descends inside the sleeve 3 as described above, and if there is a large resistance due to the thick resin burr 8, the hydraulic pressure of the cylinder 2 will be lowered. becomes larger.

A preliminary experiment is carried out in advance to determine the limit po of the resistance between the plunger 1 and the sleeve 3 to prevent molding defects, and to set po in the comparator 11.

In addition, it is generally sufficient to set po to the ÷ of the set transfer oil pressure at the time of discharge.

If p of the oil pressure during the descent of the plunger 1 becomes larger than po, an alarm buzzer 14 sounds to notify the operator that there is a risk of defective molding if molding continues.

In this case, the operator removes the resin burr 8, turns on the inspection switch 13 again, and starts molding after the alarm stops sounding.

If an alarm sounds and the resin burr 8 is removed and molded,
If resin leaks upward from the gap between plunger 1 and sleeve 3, this indicates that plunger 1 or sleeve 3 has become severely worn and can no longer be used with confidence, so replace plunger 1 or sleeve 3 immediately. It is something to do.

As explained in the above embodiment, according to the present invention, the operator does not have to pay attention to resin burrs when there is no alarm.
This eliminates the need to remove resin burrs every time, and if there is an alarm, the resin burrs are removed, eliminating the risk of molding defects due to increased resistance between the sleeve and plunger.

It also becomes clear when to replace the plunger or sleeve.

These make it possible to improve molding efficiency, improve yield, and employ unskilled workers in molding operations, thereby reducing the cost of molded products.

As described above, the present invention provides a plunger that detects abnormalities in the plunger or its operating state in transfer molding, and notifies the operator of the abnormalities to prevent defects from occurring. This invention was created with the aim of providing a transfer molding machine with an operational abnormality alarm, and can be said to be a highly practical idea.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a main part of a conventional transfer molding machine, showing its molding method, and Fig. 2 is a partial cross-sectional view of a transfer molding machine with a plunger operation abnormality alarm according to an embodiment of the present invention. FIG. 1...Plunger, 2...Cylinder,
3...Sleeve, 5...Upper mold, 6...
...Lower mold, 9...Hydraulic piping, 10...
...Oil pressure sensor, 11...Pressure setting/comparator,
12...Electric circuit for hydraulic operation control of the molding machine,
13...Inspection switch, 14...Alarm buzzer

Claims (1)

[Scope of utility model registration request] In a transfer molding machine, there is a hydraulic pressure sensor that detects the hydraulic pressure of a cylinder for driving a plunger, a hydraulic pressure detected by the hydraulic sensor when the plunger is lowered into the sleeve of the mold with the mold open, and a preset hydraulic pressure. A transfer molding machine equipped with a plunger operation abnormality alarm, characterized in that it is provided with a pressure setting/comparison device that compares the detected oil pressure with the oil pressure, and an alarm device that issues an alarm when the detected oil pressure becomes larger than the set oil pressure.