JPH03204155A - Forming machine - Google Patents

Abstract

PURPOSE:To predict and prevent breakage of a tie bar by arranging an ultrasonic sensor to the tie bar and outputting breakage signal when the detected signal of this ultrasonic sensor is larger than the reference signal. CONSTITUTION:The signal (a) detected with the ultrasonic sensor 20 is removed with excess frequency with a frequency filter 21 and becomes signal (b) and is inputted to an amplifier 22. The amplifier 22 amplifies the signal (b) and outputs it as signal (c). A comparator 23 compares level of the signal (c) and level of the reference signal, and when the level of signal (c) is higher than the level of reference signal, the breakage signal (d) is outputted. The reference level is set at a little lower than the amplitude of elastic wave generated when fine crack in the tie bar 4b progresses. Therefore, the fine crack progressing at the time of die clamping can be monitored and the breakage of tie bar 4b can be predicted and prevented. Then, by using the ultrasonic sensors corresponding to number of the tie bars, all tie bars can be monitored.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a molding machine, and more particularly to a device for monitoring damage to tie bars.

[Conventional technology]

FIG. 3 is a configuration diagram showing a conventional molding machine. In Fig. 3, a fixed platen 2 is attached to one end of the machine base 1, a link housing 3 is attached to the other end, four connecting tie bars 4a, 4b are horizontally suspended between them, and a movable platen is placed in the middle. 5 is placed. Link housing 3 and movable platen 5
The movable platen 5 is connected to the fixed platen 2 by a link mechanism 10, and the link mechanism 10 is differentially moved by the cylinder 6.
It is possible to move forward or backward relative to the machine, attach a mold (not shown), and clamp the mold. That is, the mold is installed between the fixed platen 2 and the movable platen 5, and after the mold is pressed and fixed between the movable platen 5 and the fixed platen 2, the mold is attached to the fixed platen 2.
Material is fed from the side and molded.

Tie bars 4a and 4b generally have threaded portions at the front and rear ends, respectively, and the threaded portions at the front end are fitted into the two-part nut 7 fixed to the fixed platen 2, and the threaded portion at the rear end is connected to the link. The housing is held by a nut 8 with a die-hide adjusting device, which is a NAND with a rotating device. Note that 9 is a tie bar lock device.

[Problem to be solved by the invention]

In the above-mentioned molding machines, the mold is clamped with a large force to prevent the mold from opening. This force acts on the tie bars 4a and 4b every time. The mold clamping mechanism is a toss-glue type, which is prone to overload, and in extremely rare cases, the tie bars may be damaged due to internal defects in the tie bars. Tie bar breakage usually occurs at the threaded section where the strength is weakest, resulting in an accident where the tie bar nut and the broken tie bar fall.

The present invention has been made in view of these points, and an object of the present invention is to obtain a molding machine that can detect the progress of cracks in tie bars.

[Means to solve the problem]

In order to achieve such an object, the present invention is provided with an ultrasonic sensor attached to a tie bar and a comparator that outputs a damage signal when the detection signal of this ultrasonic sensor is larger than a reference signal. It is.

[Effect]

In the molding machine according to the present invention, occurrence of cracks in the tie bars is detected.

〔Example〕

FIG. 1 is a configuration diagram showing an embodiment of a molding machine according to the present invention, and 20 is an ultrasonic sensor. In FIG. 1, the same or equivalent parts as in FIG. 3 are given the same reference numerals.

Further, FIG. 2 is a system diagram showing a signal processing circuit installed in the molding machine of FIG. 1. In FIG. 2, a signal a detected by an ultrasonic sensor 20 is filtered by a frequency filter 21 to remove excess frequencies, and is input to an amplifier 22. The amplifier 22 amplifies the signal C and outputs it as a signal C. The comparator 23 compares the level of the input signal C with the reference signal level, and outputs a damaged signal d at the rHJ level if the level of the signal C is higher than the reference signal level.

The reference signal level is set to be slightly smaller than the amplitude of elastic waves generated when microcracks in the tie bar develop. By doing this, it is possible to monitor microcracks that develop during mold clamping, and it is possible to predict and prevent damage to the tie bars. The damage signal d is input to the alarm generator 24,
Sounds an alarm during rHJ levels.

In the above embodiment, only - tie bars are monitored, but
It is also possible to monitor all the tie bars by using as many ultrasonic sensors as there are tie bars.

Further, in the above embodiment, a trouble-type mold clamping device is shown, but a direct pressure type or a mold clamping device of a type in which a mold clamping cylinder is directly provided at one end of a tie bar can also be used.

〔Effect of the invention〕

As explained above, the present invention provides an ultrasonic sensor on the tie bar and outputs a failure signal when the detection signal of the ultrasonic sensor is larger than a reference signal, thereby preventing microcracks that develop during mold clamping. This has the effect of being able to monitor, predict and prevent damage to tie bars.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a molding machine according to the present invention;
FIG. 2 is a signal processing circuit arranged in the molding machine shown in FIG. 1, and FIG. 3 is a configuration diagram showing a conventional molding machine. 1...Machine base, 2...Fixed plate, 3...Links S Ujifugu, 4a, 4b...Tie bar, 5...Movable plate, 6...Cylinder, 7...2 split plate・Throat, 8
... Dyno 1 Nand with adjustment device, 9... Tie bar opening/tuck device, 10... Link mechanism, 20... Ultrasonic sensor. Figure 2 Figure 3

Claims (1)

[Claims] A molding machine equipped with an ultrasonic sensor provided on a tie bar and a comparator that outputs a damage signal when the detection signal of the ultrasonic sensor is larger than a reference signal.