JPH0320099Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a galling detection device for injection molding molds for synthetic resin products.

<Prior art> As shown in FIG. 3, a conventional injection mold for molding synthetic resin products is equipped with a tapered cone-shaped guide body 2 in a mold body 1, and a tapered cone surface 3 of this guide body 2 is molded. A pilot bar 5 is fixed to the mold body 1 and guides the mold 4 so as to be able to move forward and backward.
The movable plate 6 is always pressed in the backward direction by the spring 7 and supported so as to be movable forward and backward,
A connecting rod 8 for coupling with the molding die 4 and a rod 9 for projecting the product W through the guide body 2 are attached to the movable plate 6, and a hydraulic cylinder 10 for moving the movable plate 6 forward and backward is attached. It is composed of.

<Problems to be solved by the invention> In the above injection mold, after molding the product W by injecting the resin with the movable plate 6 retracted as shown in FIG. As shown, the movable plate 6 is moved forward by the hydraulic cylinder 10, the mold 4 and the rod 9 are moved forward, and the product W is projected. At this time, galling may occur in the sliding parts of the molding die 4 and the tapered surface 3 of the guide body 2, the sliding parts of the guide body 2 and the rod 9, the sliding parts of the movable plate 6 and the pilot bar 5, etc. In some cases, the product W was not ejected reliably.

<Means for solving the problems> The present invention solves the above-mentioned conventional problems, and its configuration is that the mold body is provided with a guide body in the shape of a taper cone, and the tapered surface of the guide body is provided with a guide body in the shape of a taper cone. The molding die is guided so as to be able to move forward and backward, and a movable plate is supported by a pilot bar fixed to the mold body so as to be movable forward and backward by always being urged in the backward direction by a spring. In an injection mold, a connecting rod that connects with the molding die and a product ejection rod that passes through the guide body are attached, and a hydraulic cylinder that moves the movable plate forward and backward is provided in the injection molding mold, and the hydraulic cylinder is moved forward and backward. a solenoid switching valve that controls the supply and discharge of oil; a limit switch that detects the stop position of the hydraulic cylinder for forward movement; a pressure sensor that detects the internal pressure of the cylinder that moves the hydraulic cylinder forward; and a limit switch that controls the forward movement of the hydraulic cylinder by the limit switch. It consists of a calculation device that integrates the feed time to the stop position and the cylinder internal pressure from a pressure sensor, and when the cylinder internal pressure exceeds a certain set value, or when the cumulative result of the cylinder internal pressure and feed time reaches the set value. It is equipped with an abnormality notification device that displays abnormalities.

<Operation> The present invention is designed to prevent galling when the sliding surface of the mold occurs when the product is ejected due to the forward movement of the hydraulic cylinder.
By detecting changes in cylinder internal pressure and ejection time, this is displayed by an abnormality notification device.

<Example> Hereinafter, an example of the present invention will be described based on FIG. 1. Incidentally, the injection mold itself has the same structure as the conventional structure shown in FIG. 3, and its structure conforms to the explanation in the section of the prior art described above.

The main structure of the present invention is an electromagnetic switching valve 1 that controls the supply and discharge of oil pumped up by a pump 12 from an oil tank 11 for moving the hydraulic cylinder 10 forward and backward.
3, a limit switch 15 for detecting the forward movement stop position of the hydraulic cylinder 10 by means of a dog 14 provided on the piston rod of the hydraulic cylinder 10, and a cylinder internal pressure installed on an oil pipe 16 communicating with the inside of the cylinder for moving the hydraulic cylinder 10 forward. A pressure sensor 17 is provided to detect the pressure, and an arithmetic device 18 is provided to integrate the feed time until the forward movement of the hydraulic cylinder 10 is stopped by the limit switch 15 and the cylinder internal pressure measured by the pressure sensor 17, and when the cylinder internal pressure exceeds a certain set value. , or an abnormality notification device 19 that displays an abnormality when the cumulative result of cylinder internal pressure and feeding time reaches a set value.
The abnormality notification device 19 is, for example, a display panel using a lamp, a buzzer alarm, or the like.

Since the present invention has the above-mentioned structure, when the product W is ejected by the forward movement of the hydraulic cylinder 10, a signal from the solenoid a of the electromagnetic switching valve 13 is input to the arithmetic unit as shown in FIG. In the normal case where no galling occurs in the sliding parts of the mold, the cylinder internal pressure and the feed time when the limit switch 15 is turned on are within the set values, and no abnormality is displayed, as shown by curve C in the shaded area. .

However, when resistance is generated in the sliding part due to galling, the cylinder internal pressure exceeds the set value as shown by curve A, and the feed time for turning on the limit switch 15 exceeds the set value b as shown by curve B. These signals are integrated by the calculation device 18, and the abnormality notification device 1
9 indicates an abnormality.

If any of the above abnormalities are detected, production is immediately stopped, the mold is inspected and repaired, and restoration is carried out.

<Effects of the invention> As described above, the present invention supplies oil to advance and retreat the hydraulic cylinder that moves the movable plate forward and backward.
an electromagnetic switching valve for exhaust control; a limit switch for detecting the forward motion stop position of the hydraulic cylinder; a pressure sensor for detecting the internal pressure for forward motion of the hydraulic cylinder; An abnormality notification device that consists of a calculation device that integrates the cylinder internal pressure using a pressure sensor, and displays an abnormality when the cylinder internal pressure exceeds a certain set value or when the cumulative result of the cylinder internal pressure and feed time reaches the set value. With this configuration, the normal setting values for the cylinder internal pressure and feeding time during forward movement of the hydraulic cylinder to eject the product are determined, and if these settings are exceeded, the sliding part of the mold will be prevented from galling. It is designed to detect abnormalities due to
This has the effect of preventing damage to the mold.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing the main parts of the device of the present invention;
The figure is a graph showing the operation of the device of the present invention, FIG. 3 is a sectional view showing the structure of an injection mold, and FIG. 4 is a sectional view showing the protruding state of the product. 1... Mold body, 2... Guide body, 3... Tapered surface, 4... Molding die, 5... Pilot bar,
6...Movable plate, 7...Spring, 8...
Connecting rod, 9...Rod, 10...Hydraulic cylinder,
13... Solenoid switching valve, 15... Limit switch, 17... Pressure sensor, 18... Arithmetic device, 1
9... Abnormality alarm device.

Claims (1)

[Scope of utility model registration request] The mold body is equipped with a tapered cone-shaped guide body, and the mold is guided on the tapered surface of the guide body so that it can slide forward and backward, and the movable plate is always connected to a pilot bar fixed to the mold body by means of a spring. The movable plate is supported so that it can move forward and backward by being pressed in the backward direction, and a connecting rod that connects with the molding die and a rod for ejecting the product that penetrates the guide body are attached to this movable plate, and the movable plate is moved forward and backward. In an injection molding mold equipped with a hydraulic cylinder, an electromagnetic switching valve controls the supply and discharge of oil for advancing and retracting the hydraulic cylinder, and a limit switch detects a position where the hydraulic cylinder stops moving forward.
It consists of a pressure sensor that detects the cylinder internal pressure that moves the hydraulic cylinder forward, and an arithmetic device that integrates the feed time of the hydraulic cylinder to the forward movement stop position by the limit switch and the cylinder internal pressure measured by the pressure sensor. A galling detection device for an injection mold, characterized in that it is equipped with an abnormality alarm device that displays an abnormality when the above occurs, or when the cumulative result of cylinder internal pressure and feed time reaches a set value.