JPH0470111B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of monitoring molding conditions of an injection molding device such as a die-casting machine or an injection molding machine, and mainly relates to a method of displaying monitoring results. .

[Prior Art] FIG. 2 shows changes in injection speed v and filling pressure P acting on a molded material with respect to operating time t of an injection cylinder of a die-casting machine. Curve a shows the change in injection speed v, and curve b shows the change in filling pressure P.

If we pay attention to the speed of the injection cylinder of a die-casting machine, it consists of a low-speed section L and a high-speed section H. Of these, the main factor that affects the quality of molding is the injection speed v, the speed at the start of injection v ₁ The rising slope (acceleration) θ to high speed v 2 and the acceleration time t ₁ to high speed v ₂
It is common to manage both.
Furthermore, regarding the filling pressure P, the control value is the time t ₂ during which the molding material is pressurized from the pressure P ₀ when it is being pushed into the mold to the final pressure P ₁ . To manage this, conventionally, molding conditions have been detected and displayed using only either stroke or time.

[Problems to be Solved by the Invention] As described above, there are two types of reference axes for monitor display: stroke and time, each having advantages and disadvantages. That is, (1) The speed change point command is determined based on the stroke value because it is determined by the capacity of the molding material relative to the capacity of the plunger sleeve.

(2) When controlling the rising slope θ to the starting speed v ₁ , air entrainment must be taken into consideration, and in order to moderate the change in the filling rate of the molding material into the sleeve, it is controlled by the stroke value. Ru.

(3) The times t ₁ and t ₂ in FIG. 2 are monitored in units of milliseconds and are managed on the time axis.

(4) When using the stroke as a reference, the total stroke is a fixed value, so even if data is sampled at every predetermined pitch, the storage capacity is known.

(5) If samples are taken at equal time intervals based on the time axis, most of the storage capacity will be spent on sampling the conditions of the low-speed section L, and the storage of the important high-speed rise time t ₁ and boost time t ₂ The capacity is small. Therefore, in order to compensate for the accuracy of times t ₁ and t ₂ , a huge amount of storage capacity is required, which is completely unnecessary for the low-speed section L. Conversely, if the storage capacity is limited, the S/N ratio will be small for times t ₁ and t ₂ .

(6) Similarly, when using the time standard, if samples are taken at equal time intervals, the setting conditions, for example, the speeds v ₁ and v ₂ , are variable values, so the expected storage capacity to accommodate the changes is also limited. It becomes necessary. (If the overall speeds v ₁ and v ₂ become smaller, the time increases.) From these facts, the following can be found.

(1) Values to be managed by stroke should be displayed based on the stroke axis, and values to be managed by time should be displayed based on time.

(2) Even in the case of time display, the storage capacity should not be increased unnecessarily, but should be used effectively, and the S/N ratio should be
That is, it is necessary to increase the sampling ratio to the storage capacity.

(3) If only the analog display (trajectory) shown in Fig. 2 is used, it is not possible to immediately read the molding condition values at any given stroke or time, which is inconvenient.

[Means for Solving the Problems] Based on the above-mentioned requirements, in the present invention, under the molding conditions detected corresponding to the stroke of the injection cylinder and displayed based on the stroke axis, the injection cylinder A predetermined interval from a predetermined stroke position of is detected as a function of time, and the predetermined interval is detected as a function of time, and the molding conditions displayed with the stroke axis as a reference are displayed in combination with the time axis, and the predetermined The method for monitoring molding conditions is such that the width of the time axis display of the section is enlarged and displayed wider than the width of the stroke axis display.

The molding conditions include at least one of the operating speed, acceleration, and pressure of the injection cylinder, the temperature of the mold, the plunger sleeve, and the molding material, the filling pressure of the molding material, and the vacuum degree of the mold cavity. , the predetermined stroke position can be arbitrarily set within the entire stroke range of the injection cylinder, and in addition, the predetermined stroke position can be set arbitrarily within the entire stroke range of the injection cylinder.
It is automatically set by detecting that one value shows a predetermined change state.

[Function] Injection cylinder speed, acceleration, pressure, mold, etc.
When the injection stroke reaches a predetermined stroke position while the molding conditions such as the temperature of the plunger sleeve, the molding material, the filling pressure of the molding material, and the vacuum level of the mold cavity are being detected as a function of the stroke of the injection cylinder, , a predetermined section is detected as a function of time and displayed in a synthesized form, that is, in a form in which the time reference is inserted into the stroke reference. Therefore, only the portion of the molding process that is desired to be managed as a function of time can be extracted on a time axis basis, so that even if storage capacity is limited, the S/N ratio is relatively increased and detection can be performed efficiently. Moreover, the predetermined stroke position can not only be set arbitrarily by the operator, but also, for example, when monitoring time t2 shown in Fig. ₂ , it can be set from the position where the filling pressure P has reached the threshold value _P0 . If programmed, it is possible to automatically instruct changes in the stroke axis and time axis, thereby saving the effort of searching for the changed stroke position. At this time, by allowing the measurement interval on the time axis to be set as either stroke or time, the measurement range and operability can be improved.

Furthermore, due to the above effect, when displaying molding conditions that has a reference axis that is a composite of the stroke axis and time axis, a separate movable pointer is provided, and the digital value of the molding conditions is adjusted according to the operating position of the pointer. I am trying to display it. At that time, depending on whether the reference axis is stroke or time, the reference axis value displayed according to the digital value of the molding conditions is changed to the time measured from the injection start point and the current stroke if the reference axis is stroke. If the reference axis is time,
In addition to these, since the measurement is started from the point where the stroke axis and time axis change, it is particularly useful for checking the status of molding condition values that you want to manage on the time axis.

Furthermore, if we add an unprecedented method of registering and storing the trajectory of the molding conditions when the desired molded product was obtained, and then overwriting the trajectory of the current molding conditions and displaying it for comparison, it is possible to meet the required conditions. In contrast, you can see at a glance what the current conditions are.

[Example] FIG. 3 shows an example in which the method of the present invention is applied to monitoring the molding conditions of a die-casting machine.

In FIG. 3, the piston 2 of the injection cylinder 1
A plunger 4 is connected to the sleeve 9 through a coupling ring 3, and the molding material 10 in the sleeve 9 is transferred to the molds 11 and 1.
It is pressed into the cavity 13 formed in step 2. The piston 2 is operated by controlling the hydraulic fluid from the hydraulic pressure supply source 8 through the flow rate control valve 7 . A striker 5 is integrally attached to the coupling ring 3,
A magnetic scale 20 is fixed on the striker 5, and a magnetic detector 6 detects this magnetic pitch. A stroke detector 15 counts the signal from the magnetic detector 6 and converts it into a stroke St of the piston 2 of the injection cylinder 1. 16 is a flow rate controller, and the position S is set in advance on the setting device 17.
When reaching , a predetermined opening degree vo is output, and the flow rate control valve 7 is opened/closed or the opening degree is adjusted. Here, generally there are multiple amounts of both S and vo. 1
8 temporally distinguishes the stroke St, and the speed signal v
19 is a monitor device having the monitor display method of the present invention. The monitor device 19 includes, for example, a section for setting and detecting the change point _S0 from the stroke axis reference to the time axis reference and setting the time axis reference section Δt, which will be described later, a cursor for detecting and setting the high speed _v2 position, It has a section where the curve based on the set value and the curve based on the detected value are overwritten with ink of different colors. 14 is a pressure detector.

FIG. 1 shows an example of a monitor display, in which the injection speed v is displayed. In this example, the injection speed v is switched from low speed to high speed at a command point S=S ₀ , the stroke axis reference is switched to the time axis reference, and the period is set to Δt in the time setting. That is, when viewed from the monitor device 19 side, _S0 is set in advance as the stroke/time switching point, and the interval Δt is set. When the injection operation starts in this state, the speed v is obtained for the stroke for strokes below _S0 , but at the point when St= _S0 , the reference axis is switched and the monitor device 19 uses its own clock signal (for example, 1 msec), and after Δt has elapsed, the velocity v corresponding to the stroke is again obtained, and the above is combined to create a drawing as shown in FIG.

Of course, the interval between the time scales of the portion displayed on the time axis basis is appropriately widened in the horizontal axis direction, making it very easy to see, practical for management, and extremely convenient.

In Fig. 1, t ₀ is the time required from the injection start point until St = S ₀ , that is, the time required just before the high speed rise when switching from low speed to high speed, and t ₀₁ is the time required for the piston 2 to reach St = S 0. The time required to move from S ₀ to the point S ₁ where the high speed speed v ₂ is detected or set, t ₃ = t ₀ + t ₀₁ , 34 is a cursor that can be moved left and right, and the diagonally shaded part is These are display parts such as v ₂ , S ₁ , t ₃ , t ₀₁ , etc.

The one shown in Fig. 1 is different from the conventional one shown in Fig. 4a, but as shown in Fig. 4b, the rising part A to high speed has been relatively elongated, and it is extremely It will be easy to see and will be displayed in time, which is the original management standard.

FIG. 5 shows another embodiment of the present invention, in which the pressure acting on the piston 2 measured by the pressure detector 14, that is, the pressure P acting on the molded material 10 and the continuity v This is what is displayed regarding.

In this example, the stroke axis is automatically switched to the time axis by detecting that the pressure P has exceeded _P0 , and the display is performed based on the time axis as shown in the figure. , it is easy to grasp the state of change in boost time.

In this way, since the molding conditions are detected based on the time axis only for those parts that require time axis management, it can be performed with high accuracy and without increasing the storage capacity.

Furthermore, as shown in FIG. 1 described above, in the display of digital values by the movable pointer (cursor function), in the range of the time axis reference, the stroke position S ₁ corresponding to the position of the cursor 34, the injection start point 0 The time t ₃ from the change point S ₀ , the relative time t ₀₁ from the change point S 0 , the molding condition v ₂ and the like are displayed in the shaded area. This allows you to instantly read the value you want. In addition, in the stroke standard range, the above t ₀₁
will not be displayed. However, in order to achieve this movable pointer function, in the stroke axis reference range, the memory capacity to measure and store the time from the injection start point 0 for each sample pitch of the stroke is limited to the time axis reference range. In the range, a memory capacity is required to store the stroke St for each clock of time, and when the position between each sample value is indicated with the cursor 34, a straight line approximation is performed to the data on both sides. I am gaining from this. Also, time t ₃
is obtained by measuring the time t ₀ from the injection start point 0 of the change point S ₀ using a separate counter, and calculating t ₀ +t ₀₁ .

FIG. 6 shows a circuit for this purpose.

In Fig. 6, 21 is a clock that starts timing upon receiving the injection start signal, and 22 is a clock for each stroke St.
a memory 23 for receiving and storing the measured time from the injection start point 0 for each pitch of the clock 21;
23a is a _t0 measuring device that measures the time _t0 from the injection start point 0 to the change point _S0 , 23a is an _S0 setting device that sets the change point _S0 to change from the stroke axis reference to the time axis reference, and 23b is the injection St detector detects the stroke St from the start, 24 is the stroke from the start of injection
A comparator that compares whether St is smaller than the change point _S0 ; 25 and 26 are start command units; 27 is a clock;
28 is a memory for storing the stroke St measured for each pitch of the clock 27; 29 is a Δt setting device for setting the time Δt from the change point S ₀ ; and 30 is a Δt setter for setting the time Δt from the change point S0; 31 is a changeover switch, 32 is a memory for storing various molding conditions and types of reference axes, and 33 is a display for displaying these. They are linked so that they operate according to the progress shown by the arrows in the figure.

That is, at the same time that injection is started and the injection start signal is input, the S _t detector 23b begins to detect the forward stroke S _t of the injection cylinder, and the changeover switch 31 is switched. And the stroke S _t
is successively compared with the value of the change point S ₀ set in the S ₀ setting device 23a in advance by the comparator 24, and while the stroke S _t is smaller than the value of the change point S ₀ , the stroke axis reference value is , the molding conditions such as speed and pressure that are measured separately are displayed on the display 33.

Next, when the stroke S _t reaches the change point S ₀ ,
At the same time as the changeover switch 31 is switched, the start command device 26 issues a start command, and the clock 27 starts the time t.
Start timing. Then, the comparator 30 successively compares the time Δt set by the Δt setter 29,
Until time t becomes time Δt, based on the time axis,
Molding conditions such as speed and pressure that are measured separately are displayed on the display 33.

Note that when the time t coincides with the time Δt, the changeover switch 31 is switched and the time axis reference display ends. In this case, when the changeover switch 31 is switched, it is also possible to return to the stroke axis reference display.

In this manner, in the present invention, a curve displayed based on the time axis is displayed in a composite manner while the curve is displayed based on the stroke axis.

In addition, in the part that is displayed based on the time axis, the scale of the horizontal axis that displays the curve on the display 33 is set to a wide scale, and the width of the time axis display is expanded to be wider than the width of the stroke axis display. It is now displayed.

(Effects) In the present invention, as described above, the molding conditions can be monitored with high accuracy without significantly increasing the storage capacity, and the reference values suitable for the stroke reference and time reference can be displayed on one screen. You can select by.

That is, in the present invention, the same molding conditions are detected corresponding to the stroke of the injection cylinder, and a predetermined section from a predetermined stroke position of the injection cylinder is detected as a function of time, and the same molding conditions are displayed based on the stroke axis. The same molding conditions detected as a function of time are displayed on the monitor screen based on the time axis, and then the same molding conditions detected as a function of time are displayed based on the time axis, following the display based on the stroke axis. In addition, the width of the time axis display of the predetermined section is enlarged and displayed wider than the width of the stroke axis display, so that, for example, in the injection process of a die casting machine, Areas that are easier to see and manage when displayed based on the stroke axis, such as low-speed injection areas, are displayed based on the stroke axis. The condition and high-speed injection condition may be carefully observed and checked, or the rising state of filling pressure and the decreasing state of injection plunger speed from just before the end of filling to the end of filling may be carefully observed and checked. Where it is necessary to know in detail the status and stopping status of the injection plunger, it can be displayed on a time axis basis.
Furthermore, the intervals between the scales on this time axis can be appropriately widened in the horizontal axis direction to display the data in a manner that is practically effective. Therefore, changes in molding conditions are detected or checked in detail on a time axis basis during a predetermined period from a predetermined stroke position of the injection cylinder during the injection process, and the results are used in subsequent injection control. It can be used effectively and can help obtain good quality injection products.

Furthermore, in the present invention, the same molding conditions such as injection speed and injection pressure are displayed in a composite manner as a continuous line diagram, with the first half and the second half based on the stroke axis, and the middle half based on the time axis. With a single diagram, you can see at a glance the changes in molding conditions for all sections of the injection process, making it possible to clearly and easily understand the entire process with a small number of screens, which is extremely convenient.

[Brief explanation of the drawing]

FIG. 1 is a velocity diagram showing an example of the relationship between the injection stroke and time and injection speed displayed according to the present invention, and FIG. 2 is an example of the relationship between time, injection speed, and pressure displayed using the conventional method. A line diagram showing
FIG. 3 is a sectional view and electric circuit diagram showing one embodiment of an apparatus for carrying out the present invention, FIG. 4a is a speed diagram shown using a conventional display method, and FIG. FIG. 5 is a diagram showing another embodiment of displaying speed and pressure according to the present invention, and FIG. 6 is an electric circuit diagram showing still another embodiment for carrying out the present invention. . 1... Injection cylinder, 5... Striker, 6...
...Magnetic detector, 9...Sleeve, 11, 12...
Mold, 19... Monitor device, 20... Magnetic scale, 21, 27... Clock, 22... Memory,
33...Indicator.

Claims (1)

[Claims] 1. The same molding conditions are detected corresponding to the stroke of the injection cylinder, and a predetermined section from a predetermined stroke position of the injection cylinder is detected as a function of time, and the same is displayed based on the stroke axis. The same molding conditions detected as a function of time are displayed on the monitor screen based on the time axis, and then the same molding conditions detected as a function of time are displayed on the time axis. A method for monitoring molding conditions, in which the displayed items are displayed in a composite manner, and the width of the time axis display of the predetermined section is enlarged to be wider than the width of the stroke axis display. 2. Molding conditions are at least one value among the operating speed, acceleration, and pressure of the injection cylinder, the temperature of the mold, the plunger sleeve, the molding material, the filling pressure of the molding material, and the degree of vacuum of the mold cavity. A method for monitoring molding conditions as described in scope 1. 3. The predetermined stroke position can be set arbitrarily within the entire stroke range of the injection cylinder, and at least one of the molding conditions.
Claim 1 wherein the value is automatically set by detecting that the two values indicate a predetermined change state.
Method for monitoring molding conditions described in section. 4. The molding conditions according to claim 1, wherein the predetermined stroke position is a position immediately before a high-speed rise when switching from low-speed injection to high-speed injection, and the predetermined section is a section immediately before the end of high-speed injection. Monitoring method. 5. A movable pointer is provided on the stroke axis or time axis of the injection cylinder, which is the reference axis for displaying molding conditions, and the range where the reference axis is the stroke axis corresponds to the position of the movable pointer, indicating the stroke of the injection cylinder. The range in which the reference axis is the time axis includes the time measured from the start of molding (injection start) and the molding condition value, in addition to the stroke value, time, and molding condition value, and the range in which the reference axis is the stroke value. A method for monitoring molding conditions according to claim 1, wherein the time measured from the time when the axis is changed to the time axis is displayed.