JPH0234696B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold breakage detection device for a hydraulic molding machine, and its purpose is to easily detect breakage of a workpiece in-process in hydroforming processing. Therefore, it is an object of the present invention to provide a mold breakage detection device that can accurately determine whether or not a workpiece is damaged during hydroforming.

Conventionally, it has not been possible to detect breakage in the workpiece during hydroforming, and the primitive method of visually inspecting each workpiece by humans has been used, which is a cumbersome process. It was hot.

The present invention has been proposed in view of the above points, and will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the device according to the invention,
In the figure, 1 is the dome main body, 2 is a concave chamber formed in the dome main body 1 and into which liquid is injected, 3 is a stand placed on the upper part of the dome main body 1, 4 is the stand 3 and the wrinkle presser 5 The workpiece 6 is supported on a table by a table and positioned so as to cover the concave chamber 2. 6 is a punch that can move up and down for deforming and processing the workpiece 4. A punch position detection sensor 7 is attached to detect the punch position. Further, a pressure detection sensor 8 is attached to the recessed chamber 2 in the dome body 1 in order to detect the opposing hydraulic pressure as shown by the arrow, and the output of this pressure detection sensor 8 is sent to the data processing unit 10 via an amplifier 9. A pressure signal is applied to an input interface 11 of the punch position, and a signal indicating the punch position is applied to the input interface 11 from the punch position detection sensor 7. Each of the above-mentioned signals is applied via the input interface 11 to a processing section 12 such as a computer having calculation/judgment and storage functions, and is processed.
It is configured to detect the tear.

According to the above-mentioned apparatus, as shown in FIG. 2A, the punch position and the measured pressure pattern of the opposing hydraulic pressure during the molding process can be detected and stored in real time. In addition, as shown in Figure 2B, the punch position and normal pressure pattern of opposing hydraulic pressure during normal forming operations memorized in this way are compared with the measured pressure patterns during each forming operation as shown by broken lines. This makes it possible to detect breaks in the workpiece 4.

In other words, the punch position and opposing hydraulic pressure pattern when the workpiece 4 breaks during hydroforming are not necessarily fixed, and the pressure level also varies depending on the material, size, oil, temperature, etc. of the workpiece. It is something. However, the normal punch position and opposing hydraulic pressure pattern during the machining of non-defective products are reproducible as long as the machining conditions are the same. For this reason, as shown in Figure 3A, first, considering the variation in the pressure pattern when forming a non-defective product, the upper and lower pressure patterns that cover the variation are stored as the non-defective pressure pattern. Let me remember it. Then, as shown in Fig. 3B, the measured pressure pattern and the non-defective pressure pattern from each measurement are compared as shown in Fig. 3C, and in this case, the pressure of the measured pressure pattern is lower than the lower limit non-defective pressure pattern. The structure is such that if the tear is small as shown by diagonal lines, it is determined that the tear deviates from the normal variation range. Therefore, breakage of the workpiece 4 can be easily detected during the hydroforming process.

As described above, according to the present invention, there is provided a pressure detection sensor which is provided in the dome and which detects the opposing hydraulic pressure when the workpiece is pressurized by the punch, a position detection sensor which detects the movement of the punch, and a A normal opposing hydraulic pressure pattern consisting of an upper limit and a lower limit corresponding to the punch position is stored in advance, and the upper limit and lower limit are Since the data processing unit is configured to detect damage to the workpiece by comparing the range consisting of can be easily detected.

(b) Since it can be compared with the pressure pattern of a good product, it is possible to self-diagnose not only tears but also abnormalities in processing conditions and molding machines.

(c) Unmanned processing, which has been a barrier to unmanned processing in hydroforming, can be easily achieved.

There are other effects.

[Brief explanation of drawings]

FIG. 1 is an embodiment of the mold breakage detection device according to the present invention, and FIGS. 2A and 2B and 3A to 3C are explanatory views of the same operation. 1...Dome body, 4...Workpiece, 6...Punch, 7
...Punch position detection sensor, 8...Pressure detection sensor,
10...Data processing unit, 12...Processing unit.

Claims (1)

[Claims] 1. The punch, which is provided in a dome and has a pressure detection sensor that detects an opposing hydraulic pressure during pressure forming of a workpiece by the punch, and a position detection sensor that detects movement of the punch, and that is stored in advance. A normal hydraulic pressure pattern consisting of at least a lower limit corresponding to the position is compared with a measured pressure pattern obtained during molding via the pressure detection sensor and the position detection sensor, and the measured pressure pattern is determined to be a normal opposing hydraulic pressure pattern. 1. A mold breakage detection device for a hydraulic molding machine, comprising: a data processing unit that detects breakage of the workpiece based on whether or not the workpiece is below a lower limit.