JPS59120354A - Method and device for measuring injection state of injection molding device - Google Patents

Abstract

PURPOSE:To measure exactly the molding condition in an injecting stage by transmitting a pulse signal at every movement of an injection plunger for a unit distance, and detecting the section where the difference between th adjacent pulse periods is within a prescribed range as a section where the injection speed is approximately constant. CONSTITUTION:A magnetic scale 10 integral with a plunger 1 which injects a molten metal 12 into molds 5, 6 is provided, and a pulse signal is outputted from a magnetic head 11 via a converter at every movement of said scale for a unit distance. The difference between the adjacent periods is continuously measured. The fluctuating width in the speed corresponding to the level of the injection speed is determined, and the section where the above-described difference between the periods is within the range of a prescribed value is detected as the section where the injection speed is constant. The moving distance and time of the plunger are measured in accordance with the logical state of the detected signal and the average speeds V1-V4 in each section are calculated. The position and speed of the plunger and the rising the falling time of the speed in the injection stage are thus exactly and automatically measured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the injection molding process in which an injection molding device such as a die casting machine or an injection molding machine presses molten metal or plasticized resin into a mold. Rise (3) This relates to a method and apparatus for measuring injection conditions such as rise and rise time. , Below (・Otsu Daitsunostoma//Aogai nito-, -c
HH clear.

At Da Ikastomanno, the injection plan for the injection process/
The speed of y, the speed of h7 up, j>) 72 down time 2,
1. Accurately measure injection conditions such as speed switching position.
This is extremely important in terms of casting management.

Conventionally, the speed control pattern of the injection syringer of a die-casting machine is 3J shown in Fig. 1: 2 stages of low speed and high speed, and the speed control pattern is from low speed to high speed (UL to υ conversion).

This was done by a signal from a high-speed changeover switch B consisting of a limit switch for controlling the speed of the striker 2 installed in conjunction with the injection plane gage V1 as it moves forward.

In Fig. 1, there are four injection cylinders, 5 is a fixed mold, 6 is a moving metal mold, and 1 is an injection sleeve.

8 is a reverse limit switch consisting of a limit switch, etc.
9d, injection/su/da 4 and a few words/this pressure transducer.

12 is a molten metal.

(4) In the conventional method for measuring the moving speed of the injection plunger 1, a low-speed measurement period is defined as a period from the time when the backward limit switch 8 is activated immediately after the start of injection to the time when the high-speed changeover switch is activated. By measuring the travel distance and travel time of the injection plunger 1 in each measurement interval, and dividing the travel distance by the travel time, the time when the injection speed becomes almost zero from the operation time of B is defined as a high-speed measurement interval. The average speed was calculated and displayed.

A magnetic scale 10 is embedded in the striker 2, and a magnetic head 1 is arranged several times opposite to the magnetic scale 10.
1, one pulse signal is output every 4σ when the injection plunger 1 moves a unit distance. The travel distance in each of the low-speed and high-speed measurement sections is measured by integrating the pulse signals.

In addition, at the end of the high-speed measurement section (1), the pulse period of the pulse signal slows down and becomes longer.
The injection plunger is assumed to have stopped when the pulse period reaches a predetermined value. Only 1～. In the injection plunger average velocity measurement method as described above, a relay,
Solenoid valve, hydraulic circuit.

There is a time delay t1 in the operation of injection ring 4, etc.

In the low speed measurement section, d: is the average speed including the speed rise immediately after the start of injection, and in the high speed measurement section, it is the average speed including a part of the low speed region, 40% of the high speed, and the falling portion, so each It was impossible to accurately measure the uniform speed in the measurement section.

In recent years, methods for measuring the injection plunger speed switching position and switching time, which have been particularly important in casting, are as follows:
Generally, this was done by measuring the injection plunger position and time at the time of actuation of the speed control Y11 switch, but the actual position of the injection plunger 1 is determined by a relay,
1.Depending on the speed of low-speed injection due to the activation time delay of solenoid valves, etc.

There were cases in which the injection plunger 1 deviated by approximately 100 mm (L7) from the plunger position at the time of actuation of the speed control switch, posing a major problem in casting management.

Therefore, the peak pressure of the oil pressure change of the injection cylinder 4, which is directly related to the plunger speed change, is used as the trigger signal to measure the point of transition from low speed to high speed.If the position of the injection plunger 1 at that time is measured, the high speed The rising position, 4 hours, etc. were measured.

I7 or L2. Recently, the method of changing the injection speed by switching the -C hydraulic circuit using a directional control valve that causes the hydraulic phenomenon has been replaced by a method of changing the injection speed using a servo valve. In that case, the peak pressure is no longer generated, and a measurement method based on detecting the peak pressure of the injection cylinder oil pressure cannot be applied.

-Again. Record the speed pattern of the injection syringer on an electromagnetic oscilloscope, and use the recorded waveform to determine the speed rise time 9
A method of reading the position has also been implemented, but the measurement method using an electromagnetic oscilloscope requires soil and recording paper that are difficult to handle. Also, since the recording waveform is exposed to light and takes time, there are some inconveniences in data processing since it is analog data.

In recent years, high crystallinity (7) such as pressure resistance and airtightness has been required for die-cast products, and the speed control pattern of the injection plunger 1 has become increasingly necessary to have multi-step speed control as shown in Figure 2. .

An example of the injection speed control pattern in the injection process shown in FIG. 2 will be described below in 1.2.

When the injection plunger 1 starts moving, the molten metal 12 in the injection sleeve Z tends to entrain gas if the speed suddenly becomes low speed V, so the speed is gradually increased by 7□, and the speed in the injection sleeve Z is increased by 7□. While expelling air, the molten metal 12 is moved at a speed v1 that does not cool the molten metal 12 as much as possible. When the molten metal 12 reaches the gates I-113 of the molds 5 and 6, the 11 unit prevents the molten metal 12 from flying out of the gate 13 like a fountain and causing gas entrainment. In order to do this, the speed is lowered to v2, which is lower than +Vl.

When the mold cavity 14 is filled with molten metal to some extent,
Fountain flow phenomenon r1: Since it becomes difficult to occur, the speed is increased to high speed ■3 to prevent cooling of the molten metal 12. Furthermore,
As the mold cavity 14 is filled with the molten metal 12, the speed is increased to v4(8) in order to prevent the gas in the mold cavity 14 from being expelled and the molten metal 12 from cooling.

As described above, in the speed pattern of the injection syringer 1, Ul: is shown in FIG. Speed Vll V21 V
31■4 and position At, t2 and speed rise time j
4+ It is extremely important to understand t, , in an electric resistance sewing manner, and quantitative measurement of casting conditions enables efficient setting of casting conditions and monitoring of molding defects.

As mentioned above, due to the need for multi-stage speed control, the number of measurement points during the injection process has increased.2. Poor measurement timing is a factor that further reduces the reliability of measured values. or.

On the other hand, due to the injection hydraulic circuit, the injection sleeve, and the casting condition in the mold, the speed characteristics have a resonant second-order delay element.
Generally, the following injection speed phenomena are exhibited.

In the low-speed region without mixing, the injection condition is stable and the speed fluctuation range is small, but in the high-speed region, the molten metal fills the mold gears and cavities considerably! 1, the flow resistance of the molten metal changes greatly due to the influence of the shape of the mold cavity and temperature distribution, and this causes load fluctuations on the injection cylinder.

The range of variation in the injection speed is one point larger than the range of variation in injection speed in the low speed region.

Although there is no perfect solution to this phenomenon with the current level of hydraulic control technology for injection molding equipment, it is
It has become a big problem.

Therefore, the present invention takes into consideration the range of speed fluctuations in each injection process (abbreviation: 7 degrees), and accurately judges the timing of switching the injection speed to improve the molding status during the injection process. That is, the first objective is to accurately and automatically measure the Ch position, speed, speed rise, and rise time of the injection plunger. In other words, the injection plunger is set so that when the injection speed is low, the reference speed fluctuation range for determining that the injection speed is approximately constant is narrowed, and the reference speed fluctuation range becomes wider as the injection rate increases. Calculate the difference between two consecutive pulse periods from a detector that generates a pulse signal every time the position moves by 1; It is assumed to be approximately constant. In this way, even in the high speed range where the speed of the injection plunger tends to be unstable, it is possible to perform measurements with accuracy that does not affect casting, and at the same time, in the low speed range, the measurement force can be transferred with high precision. Ru.

In this way, when it is possible to detect whether the speed of the injection plunger is approximately constant, the logic state of this detection signal controls the means for measuring the travel distance and travel time of the injection plunger. It becomes possible to measure the moving distance and moving time in a substantially constant section, and if this is combined with a means for dividing the moving distance by the moving time, it is easy to calculate the 117-uniform velocity in a substantially constant section of the injection speed. A measuring device can be realized.

By controlling the means for measuring the moving position of the injection sylanger so as to perform the G1 measurement when the logic state of the detection signal changes, it is possible to easily realize a device that measures the rising position and the rising F position of the injection speed. Also.

It controls the means for measuring time so as to perform measurement while the logic state of the detection signal is in a state where the injection speed is not substantially constant.
For example, a device that measures the rise time and fall time of the injection speed can be easily realized.

(11) Next, the outline of the method of the present invention will be explained with reference to the drawings. Figure 1 is a block diagram of the injection state measuring device of the injection molding apparatus according to the embodiment of the present invention. Movement position detection The device 15 outputs a pulse signal P10 every time the injection plunger moves by a unit distance, and the tarfj puffer signal generating section 16 generates a timing signal as necessary based on the pulse signal e+ -Fj I)+J. The relationship between the pulse signal (■)!] and the timing signal generated by the timing signal generator 16 is shown as a timing chart in FIG.

After the first time measurement unit 17 is reset at the first timer Ti, the first time measurement command signal P a 1 becomes ``1''. Continue measuring for 1 hour while P(I+ becomes 0'', change the open side of time to 11.
Congratulations, the so-called '1111 hours up to that time will be maintained.

Similarly, the second timer side 18 is reset by the second reset signal MRS T2, and then continues for one hour while the second timer command signal 1)G2 is "1". G1 of
Continuing to measure +P (When 12 reaches 0, the time is measured at 11-1, and the 31 time measured at 1 (12) is maintained.

The energy reduction unit 19 outputs a difference of 9 between the measured times between the first time measurement unit 17 and the second time measurement unit 18, and sends this output to the setting unit 20.
The comparison unit 21 compares the set value with the set value of .

If the difference between the two measurement times is within the specified range, the output signal is
1''.First timekeeping command PGl and second timekeeping command 1〕o
2, as shown in the timing chart of FIG. 4, from "1" to 4U where the pulse signal Ps is input.
” or from “0” to °゛1”, and the logic state is reversed in Pal and 1]G2. , the first time measuring section 17 and the first time measuring section 18 measure the current pulse period and the previous pulse period of the pulse signal Ps at approximately the end of one period of the pulse signal PS. Therefore.

The timing signal generator 16 generates a pulse signal Jrl1. p,
If a data holding command signal ST is generated at approximately the end of one cycle of
The output signal PTl+ from 2 is +118+ while it is within the predetermined range 1, which is the difference between the adjacent periods of the pulse signal PIJ.
becomes. That is, in the interval where the speed of the injection plunger is approximately constant (-), the output signal P T I+ of the holding circuit 22 becomes 1.1111+, so the relationship between the injection speed P T I+ and the output signal PTH of the holding circuit 22 is It will look like Figure 5.

If a shift register section 23 operating at the leading edge and trailing edge of the output color Q, 1:'TR of the holding circuit 22 is connected.

The output signal of the shift register section 23 is shown in FIG. 5:
Since the software changes, a known time d1 measurement circuit 24.
24a, injection plunger travel distance reduction circuit 25. 2
5 a, 25 b, travel time reduction circuit 26° 26a
+ 26b and the signals used to control the measurement period of the moving position 81 measuring circuit 27 are as indicated in 2. on the injection speed pattern in FIG. Molding-I=Important time, speed 1 It is possible to measure the position. 28°28a, 28b
is a divider, 29 and 29a are measurement time indicators, 309
．． ') Oa, 3 Q b is the measurement speed indicator, 3
1, 31a is a measurement position indicator.

Hereinafter, the method and apparatus of the present invention will be explained in more detail based on examples.

FIG. 2 shows an external wiring diagram of one embodiment of the present invention. Piston rod 4a of injection cylinder 4 or injection plunger 1
A magnetic scale 1 [) is embedded in the striker 2, which is a rod connected to the magnetic head 10, and the signal is converted based on the signal 'FJ' from the magnetic head 11 mounted opposite the magnetic school 10. By vessel 32.

One pulse signal is output to 4B when the piston rod 4a moves 111 distance. Upon receiving the pulse signal,
The injection state measuring device 3b automatically performs measurement during injection.

Figure 6-6-1) + (1)) shows an electrical block diagram of one embodiment of the present invention. Each time the injection plunger 1 moves by a unit distance, the movement position detector 34 including the converter 2 outputs one pulse signal. Pl)
Then, Ps is input to the second pulse period multiplier circuit 7 via the first pulse period multiplier circuit 35 and the inverter 6. Ru. The output signals PTI + PT2 of the two pulse period multipliers 35 and 37 change as shown in the timing chart of FIG.

In order to integrate the period of the pulse signal QPs, a setting device 38,
An A N 1) gate (13 is Shinyumi-
It is opened and closed by P and I. Signal Po1ld, +PT1+
ANDK-1 with PT2 as a human signal output from the mountain
do. While P U I is °1'', the first pulse period force counter 40 integrates the pulse period P.

While P+B is 110I+, that is, the next pulse family 1υ1
During this period, the integrated value is held. During this period, the second pulse period counter 41 +I"rl+: The output signal of the NOR key -1 with i.T2 as a human input (sub.
is 1'', the clock pulse signal from the clock pulse generator 39 is integrated via the AND gate 04 to calculate the pulse period. The second pulse period counter 4i i/-i alternately integrates and holds the period of the pulse Shingetsu Ps.The first and second pulse period counters 40 and 41 are configured to Since the accumulated value must be calculated by the operator 1., it is necessary to stabilize the multiplier at 42° and 43°, respectively. The pulse width of the reset signal RS T I IRS T 2 and the pulse signal Ps is 2 compared to the period of P).
It can be made so short that it can be ignored.

To compare whether the difference between the output signals of the first pulse period counter 40 and the second pulse period counter 41, that is, the pulse period difference, is within a predetermined range, it is necessary to use the subtracter 44 and its This can be done by a complement circuit 45 which takes the absolute value of the subtraction result, and a comparator 47 which compares the set value of the setter 46 with the output signal of the complement circuit 45.

However, as shown in FIG.
By adjusting the resolution of the comparator 48, the output signals of the first pulse period counter 40 and the second pulse period counter 41 can be adjusted by adjusting the resolution of the comparator 48. This can be equivalent to determining whether the difference between the pulse periods measured at 41 and 41 is within a predetermined range.

Based on this idea, the first pulse period counter 40
and the output signal of the second pulse period counter 41 to the comparator 48
When they match, the output signal is set to 1''.
Adjustment can be made by not using an appropriate low order number of output signals of the pulse period C/40°41 as a manual signal for the comparator 48. In fact, the comparison resolution of the comparator 48 can also be adjusted by changing the oscillation frequency of the clock pulse generator Otsu 9.

1st. Timing U11 for comparing the output signals of the second pulse period counters 40 and 41. -1115 counter holds the immediately preceding pulse period, and 4. - It must be at the time when the other counter has completed the integration of the current pulse period. This timing signal B, also called a strobe signal
T is generated by a monostable multivibrator 49 operating at the leading edge of the pulse signal (1) J, and the output signal of the comparator 48 is held by a 7-linobe flop 50. Note that the pulse width of the -timing signal ST can be made so short that it can be ignored compared to the period of the pulse signal 1]s. - Note - 7 Rinozono ■ The J tube 50 has a non-inverting output signal Q and an inverting output signal 4, and by combining a monostable multivibrator 54, 52 and an AND gate G5, a non-inverting output is obtained. The pulse signal PTR is generated at the leading and trailing edges of the signal Q. The pulse signal P T Rh is input to the NFT register 53 to generate an operation command signal to each measuring circuit.

FIG. 9 shows how the output signals Q and Q of the Frisopf V1 knob 50, the pulse signal F'i PTR, and the output signals of each output terminal number of the shift register 53 are related to the injection speed putter/. Shown below.

As can be seen from Fig. 9, if you measure the time during which the signals 1 and 5 are at °゛1'' at the output terminal r of the infeed register 5', you can determine the rise time of each injection speed. Output terminal numbers 2, 4 and 6 of shift register 5
If we measure the distance and time the injection sylanger moves while the signal 8 is '1'' and divide by 21, we get:
The average injection speed in each section is obtained. If you measure the moving position of the injection plan at the leading edge of the signals of shift register output terminal numbers 4 and 5;
If you know the range of speed that passes through +, you can.

As shown in FIG. 6(b), in order to measure the velocity amount of the injection bufunjar - L · time, as shown in FIG.
Using GI4 + () + 5, shift register [5
The output signal of output end r of 3-41 and 5 is "i"
At this time, the clock pulse signal from the reverse pulse generator 54 is made to be equal to the product t9 of the first and second rise time counters 55+55a-\. 5
6,568 each have a rise time indicator -〇. The average injection speed is also measured using a similar configuration, with moving distance counters 57, 57a, +57b, 1 to 1 corresponding to each section.
57c is integrated with the pulse signal Ps, and the moving time counter 5
8,58a.

By integrating the clock pulses from the rJ Knockles generator 54 on 58b + 58C and dividing the former integrated value by the latter integrated value using 21 dividers 59, 59a, 59b, and 59c, the Injection speed is displayed. 60. 60a, 60b, and 1c are average injection speed indicators, respectively. 31 measurement of the ifr and injection speed switching position, by integrating the pulse signal PS, the latch circuit 61.61a that holds the human input signal at the leading edge of the output signal of the output terminal numbers 4 and 5 of the shift register 5 is set. The position of the injection plunger is measured and displayed by connecting it to the injection stroke counter 62 which outputs the position of the injection plunger.

63 and 63a are injection speed switching position indicators, respectively.

In this way, in one aspect of the present invention, when the injection plunger is moved at multiple speeds, the injection speed is automatically measured in a section where the injection speed is approximately constant, without the operator having to set the measurement section of the average speed in each section. It is possible to measure and display the average speed at the injection speed, and it is possible to measure and display the injection speed switching position without using surge pressure at the time of speed switching.

Furthermore, the injection speed was recorded using an electromagnetic oscillograph, etc.
Since it is possible to measure the speed and time of the injection plunger without having to use the machine, the operability of measuring molding conditions in a die-casting machine has been dramatically improved.

Highly reliable measurement becomes possible, allowing efficient setting of molding conditions and constant monitoring of molding conditions.

Although the example of application to a die-casting machine has been described above, F7 can also be applied to an injection molding machine in a similar manner.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional device. - Injection speed. The pressure diagrams, Figures 2 to 9 show examples of the present invention,
Fig. 2 is a longitudinal sectional view and injection speed diagram of a device for carrying out the method of the present invention, Fig. 3 is a block diagram showing one embodiment of the injection state measuring device, and Fig. 4 is a block diagram showing an embodiment of the injection state measuring device. FIG. 5 is a timing chart corresponding to the one in FIG.
a, ), (b) ii Electrical Block 2 Figure 7 is a timing chart corresponding to that in Figure 6, Figure 8 is a line diagram showing another embodiment of a part of what is shown in Figure 6; Figure 9 is the 6th
FIG. 3 is a diagram showing the relationship between the injection speed pattern and the output bow corresponding to the one shown in the figure. 1... Injection plunger, 4... Injection cylinder. 5.6... Mold, 7... Injection sleeve, 10...
Magnetic scale, 11...magnetic-\throat, 15.34.
...Movement position detector, 17.18...Time measurement section. 20... Setting section, 21... Comparison section, 22... Holding circuit, 23.53.../foot 1/jista, 40.41
... C) (S cycle counter. Patent applicant: Ube Industries Co., Ltd. (23) Figure 1 Procedural amendments 1981 - August 1980 - Commissioner of the Japan Patent Office Toshiro 1 Indication of the case Patent application No. 1983-227573 2 Name of the invention Injection condition measuring method and device b for injection molding equipment Relationship with the case of the person making the amendment Patent applicant Zip code 755 1-12-32 Nishihonmachi, Ube City, Yamaguchi Prefecture Ube Industries Co., Ltd. Patent Department Telephone 03 (581) )33N 4 There is no daily amendment order for the supplementary IF order. 5 Detailed explanation column of the invention of the specification subject to amendment. 6 Contents of amendment (1) 1-5 on page 4, lines 16-17 of Seiwa is a fixed mold, 6 is a movable mold, and -1 is corrected to "-5 is a ringing mold. 6 is an identified mold." Below -F

Claims (5)

[Claims] (1) Consists of means for generating a pulse signal every time the injection plunger of the injection molding apparatus moves a unit distance in synchronization with the movement of the injection plunger, and means for detecting the pulse signal. In the method of measuring the injection state using the pulse signal,
The difference between adjacent periods of pulse signals generated as the injection plunger moves is continuously measured, and the period in which the period difference is within a predetermined value range is determined. A method for measuring an injection state of an injection molding apparatus, characterized in that the injection speed of the injection plunger is detected as a section in which the injection speed is substantially constant. (2) The period of the pulse signal is alternately measured in synchronization with the pulse signal from the detector which generates a pulse signal every unit distance traveled in synchronization with the movement of the injection plunger of the injection molding device. Two independent measuring means are provided,
By configuring so that while one of the two systems of time measuring means measures the pulse period, the other system holds the measured time, that is, the previous pulse period. and a comparator that determines whether the difference between the two measured time output signals from the two systems of time measuring means is within a predetermined range. , and a holding circuit that holds the output signal of the comparator at the fault point r of one cycle of each pulse signal. An injection state measuring device for an injection molding apparatus, comprising means for detecting a section in which the moving speed of an injection plunger is substantially constant. (3) means for measuring the position in front of the moving vehicle of the injection plunger by integrating pulse signals from the detector in correspondence with the logic state of a signal that detects that the moving speed of the injection plunger is substantially constant; During that period, the injection plunger moves at a substantially constant injection speed by simultaneously measuring the travel time of the injection plunger and by dividing the travel distance of the injection plunger opened by the above two means by the travel time. 3. An injection condition measuring device for an injection molding apparatus according to claim 2, comprising a q divider that outputs an average injection speed of 19 in a section. (4) By giving an old measurement command number to the means for opening the movement position of the injection plunger in response to a change in the logic state of a signal that detects that the movement speed of the injection plunger is substantially constant. An injection state measuring device for an injection molding apparatus according to claim 2, which measures the speed switching position of an injection plunger. (5) A signal detecting that the moving speed of the injection plunger is substantially constant outputs an opening command signal to the means for measuring one hour while the moving speed is substantially constant and is in a logical state. By this, the injection sylanger speed rise time,
An injection state measuring device for an injection molding apparatus according to claim 2, which measures velocity fall time.