JPS63220968A - Injection condition monitoring apparatus - Google Patents

Abstract

PURPOSE:To inform actual working difference by mechanism condition and to improve the working accuracy by recording a stroke displacement scale matching to pulse from a displacement counter at the time of command of velocity changing on a stroke displacement and velocity record in a recorder. CONSTITUTION:The displacement of magnetic scale 5 of a rod 2 for plunger 3 injecting molten metal 19 in a sleeve 18 of an injecting machine is converted 10 into a displacement of magnetic detector 8 making the standard of the original point 6, and recorded on the paper 26 of the recorder 25 as a stroke displacement S3 and a stroke displacement velocity S4 by a D/A converter 20 and a differentiator 21. At the time of outputting the velocity changing command 11 by signal from a position setter 12 to the signal of displacement converter 10, the velocity changing command 11 is sent to a scale signal 29 converting it to the pulse 27 matching to the displacement counting 9 and the recorder 25 by a scale signal output means M1 and recorded S9. The actual working difference caused by working delay of a control valve 15 to the velocity changing command 11 and compression, inertia, etc., of fluid is informed, and the improvement of the working accuracy is used as an indicator.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an injection condition monitoring device for monitoring and displaying molding conditions of an injection molding apparatus such as a die casting machine or an injection molding machine. In other words, it relates to an injection condition monitoring device that measures and records the motion conditions of a cylinder, such as by determining the stroke displacement of a cylinder such as a die-casting machine, and by differentiating the stroke with respect to time and converting it into cylinder speed and cylinder acceleration. be. This injection condition monitoring device is mainly used in cases where the cylinder speed is changed in multiple stages within the movement range of the cylinder, as typified by injection cylinders of die-casting machines, etc., and there are frequent opportunities to adjust the changes in the cylinder speed. It is attached to a certain cylinder.

[Conventional technology]

Conventionally, as typified by the injection cylinder of a die-casting machine, the cylinder speed has been changed in multiple stages at arbitrary cylinder stroke positions, and this speed setting is directly related to the performance of the die-casting machine, that is, the quality of the molded product. In some cases, injection condition monitoring devices have been installed to control the operating conditions of the cylinder.

FIG. 8 shows a typical mechanism thereof.

An injection plunger 3 is connected to the loft 2 of the injection cylinder 1, and by moving the rod 2 to the right in the figure, the molten metal 19 in the sleeve 18 is transferred into a mold cavity (not shown). eject. At this time, in order to measure and manage the injection process, a magnetic scale 5 is fixed to the loft 2 or the injection plunger 3 via an arm 4 so as to move integrally with the loft 2 or the injection plunger 3. Therefore, rod 2.
Injection plunger 3. Each magnetic scale 5 is a moving object.

Here, the structure of the magnetic scale 5 is arranged at equal intervals (for example, 1 m
The scale is made by alternately making magnetized parts and non-magnetized parts at intervals of m), and this magnetized part or non-magnetized part is detected by a magnetic detector 8, and sent to a counter 9 as a pulse-shaped output signal. The feed is converted into the relative displacement amount of the rod 2. The origin detector 6 is used to detect a specific point provided on the magnetic scale 5 and initialize the scale position of the injection cylinder 1, that is, the position of the rod 2. The initial position of 2 is detected by the origin detector 6.
Output with the detection signal. The displacement converter 10 includes a counter 9
The stroke position of the rod 2 is converted into an absolute displacement based on the relative displacement amount of the rod 2 from and the initial position signal from the origin setter 7. Therefore, the origin detector 6. Origin setter 7, i-ki detector 8. Counter9. The displacement transducer 10 constitutes a displacement detector.

Reference numeral 11 denotes a speed change command device, which generates a speed change command signal as a high-speed switching signal when the stroke displacement signal from the displacement converter 10 matches the cylinder speed change position preset in the position setting device 12. do. Upon receiving this speed change command signal, the flow rate controller 13 opens and closes the valve body of the flow rate control valve 15 to the pulp opening preset in the opening setting device 14, and then opens and closes the valve body of the flow control valve 15 through the hydraulic circuit 16. The flow rate is adjusted so that the moving speed reaches a desired value. 17 is a hydraulic pressure source such as a hydraulic pump.

On the other hand, in order to manage the motion conditions such as the stroke displacement and speed of the rod 2 of the injection cylinder l during the injection process, the stroke displacement signal from the displacement converter 10 is transferred to a digital-to-analog converter (hereinafter referred to as rD/A converter). )2
The cylinder velocity is obtained by converting the stroke displacement into an analog quantity using 0 and at the same time differentiating the stroke displacement with respect to time through a differentiator 21. The three signals, the high-speed switching signal, the stroke displacement signal, and the cylinder rod speed signal, are input via amplifiers 24, 22 and 23, respectively, to a recorder 25, such as an electromagnetic oscilloscope, and are recorded. .

FIG. 9 shows the injection cylinder 1 according to the mechanism shown in FIG.
This is an example of the recording output when the speed is changed. Trajectories 81 to S4 are generally drawn on the recording paper 26 output from the recorder 25 in order to measure the motion conditions of the injection cylinder 1 during the injection process. The trajectory S1 is a time axis (in the figure, time passes from left to right), and the output signal for drawing this trajectory is generated inside the recorder 25 as a speed monitor function of the recording paper 26, for example. The scale is marked at 0.1 second intervals. A trajectory S2 indicates a high-speed switching signal which is an output signal from the speed change command device 11, a trajectory S3 indicates a stroke displacement of the rod 2, and a trajectory S4 indicates its speed. Also, pulse-like waveform 35. S6 are the waveforms of stroke displacement and velocity calibration signals, respectively, and the trajectories S3. It is used as a standard for reading the actual value of S4. S7 is the stroke 0 (zero) mm line, S
8 indicates a line with a speed of O (zero) m/sec.

In a die-casting machine, the motion conditions during the injection process are measured because they have a significant effect on the quality of the molded product, and slight differences in conditions can cause defective products. For example, even if you determine the cylinder stroke position at which the cylinder injection speed is switched from low to high speed and set it in the position setter 12 in FIG. 7, the point where the speed actually starts to rise, that is, the point P1 in FIG. There is a difference of several tens of millimeters from the switching point P2 of the high-speed switching signal output from the change command device 11.

This is due to the control delay of the entire position detection mechanism shown in FIG. 8, the operation delay of the flow rate control valve 15, and the compressibility and inertia of the working fluid itself.

Therefore, in order to clarify such unclear factors and grasp the actual injection state, measurements shown in Fig. 9 are performed from time to time. However, in order to obtain the stroke displacement Sa at point P1, for example, calibration is required. Length 1 on the recording paper 26 of the signal S5 and the stroke displacement signal S3 at the point P1
0 and la, and assuming that the calibration signal S5 corresponds to the actual injection cylinder stroke SO,
The calculation of 5a=SO.41a/IIO must be performed. Similarly, in order to obtain the stroke displacement sb of the high-speed switching signal input point P2, it is necessary to measure the length zb of the point P2 on the recording paper 26 and calculate 5b=so·II b/10. 5a-sb is determined from the above Sa and sb, and the response delay between the set value and the actual speed displacement is determined.

[Problem that the invention seeks to solve]

However, the above method is not efficient because the measurement work is complicated, even if it is attempted to obtain the optimum casting conditions by changing the setting conditions little by little during on-site work. Furthermore, when measuring the length 20, la on the recording paper 26, errors tend to occur.

The present invention has been made in view of these points, and an object of the present invention is to provide an injection condition monitoring device that can perform measurement work efficiently and accurately.

[Means for solving problems]

In order to achieve such an object, the present invention includes a displacement detector that measures the stroke displacement of a moving object, and a recorder that records the stroke displacement signal of the moving object and the speed signal of the moving object from the displacement detector. In an injection condition monitoring device comprising: a scale that outputs a pulse-like scale signal corresponding to a predetermined stroke interval using a high-speed switching signal as a starting point when outputting a stroke displacement signal of a moving object and a speed signal of a moving object to a recorder; - A signal output means is provided.

[Effect]

In the present invention, scale signals are output at predetermined stroke intervals with respect to the stroke displacement signal and the injection cylinder speed signal, starting from the high speed switching signal.

〔Example〕

FIG. 1 is a system diagram showing an embodiment of an injection condition monitoring device according to the present invention, and this device includes a scale signal output means M
It is characterized by having 1. In this figure, the same or equivalent parts as in FIG. 8 are given the same reference numerals. In this device, the stroke displacement signal from the displacement converter 10 is inputted to the counter 28 through the pulse gate circuit 27, and after the pulse gate circuit 27 is opened, the first stroke shown in FIG. Every time the stroke displacement signal PS (one signal output for every 1 mm of stroke displacement) matches the stroke displacement amount preset in the scale setting device 29, a pulse-like coincidence signal is output, and this signal is sent to the amplifier 3.
0 to the recorder 25. At this time, a plurality of values may be set in the scale setter 29, and each matching signal may be outputted by changing the gain of the amplifier 30. The pulse gate circuit 27 is supplied with a high speed switching signal (see the peak in FIG. 2) from the speed change command device 11, so that the pulse gate circuit 27 is opened by this signal.

Here, the counter 28, the scale setting device 29, etc. are devices that simultaneously output a pulse-like scale signal corresponding to a predetermined stroke interval when outputting a stroke displacement signal of a moving object to the recorder 25. can.

FIG. 3 shows the output according to the embodiment of FIG.

Here, the same parts or equivalent parts as in FIG. 9 are given the same reference numerals. The trajectory S9 is a scale signal of stroke displacement, and if values of 10 mm and 50 mm are set in the scale setter 29, for example, the gain of the amplifier 30 is different at 10 mm intervals and 59 mm intervals, so it is difficult to examine the stroke displacement. For example, switching point P1 from low speed to high speed
The injection stroke position is on the scale with a ruler at point P1)
31, it can be easily recognized as 20mm. However, in Figures 1 and 3, the stroke displacement signal and scale signal are treated as separate signals, so
The number of channels required for the recorder 25 is also different, which is somewhat inconvenient and uneconomical.

In this case, if both signals are combined into one signal as shown in FIGS. 4 and 5, this drawback can be overcome.

FIG. 4 is a system diagram showing a second embodiment of the present invention.

In the figure, 22a is an amplifier as an adjustment circuit;
2b is an amplifier as a current amplification circuit, and 32 is a signal converter. In FIG. 4, the same or equivalent parts as in FIGS. 1 and 8 are given the same reference numerals. In the system shown in FIG. 4, the stroke displacement signal and the scale signal are combined into one signal by an amplifier 22b, and the signal is output to the recorder 25.

FIG. 5 shows the output. In FIG. 5, the same or equivalent parts as in FIGS. 3 and 9 are given the same reference numerals. The trajectory SIO is the stroke displacement signal 33. shown in FIG. The output signal is a composite of the scale signal S9, which has the advantage of reducing the number of channels of the recorder 25 and immediately reading the stroke displacement after high-speed switching. In addition, in FIG. 4, M2 is a scale signal output means.

Above 1st. The second embodiment has the great advantage that the calibration shown in FIG. 9 is unnecessary. Further, in these embodiments, the stroke displacement of the cylinder is illustrated, but the same applies to the speed signal S4. In addition, it can be applied to any method that measures the displacement, velocity, etc. of a moving object in a similar manner, and the effects are exactly the same.

FIG. 6 is an example of the circuit of the amplifier 22 shown in FIG. 1 as an embodiment of the present invention.
It consists of b. The stroke displacement signal of the D/A converter 20 passes through the resistor RB, the adjustment circuit 22a, and is input to the record 25 by the current amplification circuit 22b. Al and A2 are linear amplifiers, Rf is a variable resistor for gain adjustment, and RZ is a variable resistor for zero point adjustment. Tri is a current amplification transistor, and in order to generate an output signal (current) proportional to the input voltage, a circuit is constructed of resistors RA, RC, RD, and R1.

FIG. 7 is a circuit diagram showing a part of the scale signal output means M2 shown in FIG. 4 as an embodiment of the present invention. In this figure, the same or equivalent parts as in FIG. 6 are given the same reference numerals. The output signal of the D/A converter 20 and the pulsed coincidence signal from the counter 28 are combined by a linear amplifier A2 using an amplifier 22a, a signal converter 32 composed of a resistor RE, a transistor Tr2, and a capacitor C.

Next, the operation of the circuit shown in FIG. 7 will be briefly explained. Transistor Tr2 is cut off during steady state.
The output signal of the counter 28 and the constants of the resistors RE and R2 are determined in advance. Further, when the counter 28 generates a match signal, the match signal level of the counter 28 and the resistors RE and R2 are determined so that the transistor Tr2 becomes sufficiently conductive. Under this condition, the potential of the node N of the current amplification circuit 22b in FIG.
0, when the transistor Tr2 is cut off, the circuit operates in the same way as the circuit shown in FIG.
r2 becomes conductive, a current 11 determined by a circuit constant between the emitter and collector of the transistor Tr2 flows, and a potential 2 is obtained at the emitter of the transistor Tr2. This potential becomes a potential V1 divided by the sliding point of the resistor R2, and acts as a disturbance on the potential vO of the node N of the amplifier 22b as a differential current determined by the charge/discharge constant of the capacitor C, causing a coincidence signal to be generated in the stroke displacement signal S3. can be synthesized. As a result, the signal S3 shown in FIG. 5 is obtained.

In order to overlap the two types of signals at intervals of 10 mm and 50 mm as described in the second embodiment, the circuit shown in FIG. 7 may be formed into two series, and the divided potential 1 of the resistor R2 may be set to different values.

FIG. 7 shows a scale signal output means M2 constituting the second embodiment.
Although this was an example, the position of the signal synthesis point N is the resistance RB,
There is no problem in any position: RZ, Rf, RA, RC, or RD.

In the above embodiment, it has been described that the scale signal is recorded as a pulsed signal, but the scale signal is recorded in the recorder 2.
By overlapping the energy of the light source No. 5, it is also possible to use methods such as gradation of the stroke displacement signal, spots, or disappearance of the stroke displacement signal.

C Effects of the Invention As explained above, the present invention makes it easy to determine the stroke displacement by outputting the stroke displacement signal of the cylinder and its scale signal together or in combination when determining the motion state M of the cylinder. This has the effect of making it easier and more efficient to set conditions during on-site work, and it also has the effect of drastically reducing measurement errors found in conventional equipment, improving accuracy. .

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of the injection condition monitoring device according to the present invention, FIG. 2 is a time chart showing stroke displacement signals and high-speed switching signals, and FIG. A plan view showing an example of the description, FIG. 4 is a system diagram showing a second embodiment of the injection condition monitoring device according to the present invention,
5 is a plan view showing an example of recording paper in the device shown in FIG. 4, FIG. 6 is a circuit diagram showing an amplifier that constitutes the device shown in FIG. 1, and FIG. 7 is a diagram illustrating the device shown in FIG. 4. FIG. 8 is a circuit diagram showing a part of the scale signal output means, FIG. 8 is a system diagram showing a conventional device, and FIG. 9 is a plan view showing an example of writing on recording paper in the device of FIG. ■...Cylinder, 2...Rod, 3...Injection plunger, 4...Arm, 5...Magnetic scale, 6...
... Origin detector, 7... Origin setter, 8... Magnetic detector, 9.28... Counter, 10... Displacement converter,
11...Speed change command device, 12...Position setting device, 1
3...Flow rate controller, 14...Opening degree setting device, 15...
・Flow rate control valve, 16... Hydraulic pressure circuit, 17... Hydraulic pressure source, 18... Sleeve, 19... Molten metal, 20...
・D/A converter, 21... Differentiator, 22.23, 24
．． 30... Amplifier, 25... Recorder, 27... Pulse gate circuit, 29... Scale setting device, Ml... Scale signal output means.

Claims (2)

[Claims] (1) In an injection condition monitoring device comprising a displacement detector that measures the stroke displacement of a moving object, and a recorder that records the stroke displacement signal of the moving object and the speed signal of the moving object from the displacement detector, The present invention further includes a scale signal output means for outputting a pulse-like scale signal corresponding to a predetermined stroke interval using the high speed switching signal as a starting point when outputting a stroke displacement signal of the object and a speed signal of the moving object to the recorder. Features of the monitor device. (2) The scale signal output means has a signal synthesizer that overlaps a pulse-like scale signal with at least one of the stroke displacement signal of the moving object and the velocity signal of the moving object and outputs the resultant signal as one signal. An injection condition monitoring device according to claim 1, characterized in that: