JPH04143062A - Method for adjusting parallelism of platen of molding machine - Google Patents

Abstract

PURPOSE:To facilitate the adjustment of the distances between a stationary platen and a rear platen by providing distance adjusting mechanisms on respective tie bars in such a manner that the distances between the stationary platen and the rear platen coincide within permissible ranges. CONSTITUTION:The stationary platen 2 and the rear platen 4 are coupled by the plural tie bars 5 and a movable platen 3 is freely slidably mounted to the tie bars 5. The mechanisms for adjusting the distances between the stationary platen 2 and the rear platen 4 consisting of screw parts 9, tie bar nuts 10 and servo motors 11 for distance adjustment, etc., are provided in the mold clamping parts coupled via mold clamping mechanisms 6 to the rear platen 4. The distances between the stationary platen 2 and the rear platen 4 at the respective tie bars 5 are then measured by laser measuring instruments and the distance adjusting mechanisms are so operated that the respective measured values coincide within the respective permissible ranges. The tentative mold clamping operation is then carried out and these operations are repeated until the distances between the platens 2 and 4 coincide within the permissible ranges.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a mechanism for adjusting the parallelism between platens in a molding machine such as an injection molding machine that performs molding by attaching a mold to a platen of a mold clamping section.

Molding machines that use conventional molds, like injection molding machines, are equipped with a fixed platen, a movable platen, and a rear platen in order to clamp the mold and maintain the lock-up state, and the fixed platen and rear platen are connected by multiple tie bars. combined,
Further, there is a device in which a movable platen is slidably attached to the tie bar and includes a mold clamping portion coupled to the rear platen via a mold clamping mechanism.

In this type of molding machine, the movable platen is advanced toward the stationary platen by a mold clamping mechanism to come into contact with the mold, and then the movable platen is further advanced slightly from this position to perform lockup. The mold clamping force is maintained by the contraction force of each tie bar that stretches slightly during lockup.

At this time, in order for the mold clamping force to act evenly on the parting surface of the mold, it is necessary that the elongation of each tie bar be equal. To meet this requirement, each tie bar is usually made of the same material and has the same cross-sectional diameter, so the distance between the fixed platen and the rear platen at each tie bar point of the multiple tie bars connecting the fixed platen and rear platen must be made equal. It is important to.

However, in the past, none of this type of molding machine was equipped with a special mechanism that could individually adjust the length of multiple tie bars, and if a discrepancy in the parallelism between the fixed platen and rear platen was discovered, for example, the mold clamping If the mechanism is a toggle type, the die-hide adjustment mechanism (a tie bar nut with a sprocket gear fixed by a bolt is screwed into the threaded part of each tie bar that protrudes behind the rear platen, and a single continuous chain is threaded around these gears. When making adjustments, remove the bolts that connect the tie bar nuts and sprocket gears (the mechanism in which this chain is driven by a motor) to eliminate the chain connection between each tie bar, and then rotate each tie bar nut individually by hand. The distance between the fixed platen and the movable platen at each tie bar location described above is adjusted. In this case, the sprocket was rotated in different directions, right and left, for each tie bar, without taking into account the effects of backlash between the screw and tie bar nut.

In addition, to detect deviations in parallelism, we measure the elongation of each tie bar partially using an IMS gauge, or measure the distance between the fixed platen and the rear platen at several locations using an internal micrometer. , it is time-consuming and
The accuracy of parallelism adjustment is low because the whole is converted from partial measurements.

Furthermore, for those without a die-hide adjustment mechanism as described above, the inclination of the platen may be adjusted by hoisting the fixed platen and movable platen one by one using a crane, and inserting shims between the bottom surface and the bottom surface of these platens. is taking.

Please note that such parallelism adjustment is necessary not only during assembly at the factory, but also at the user's end after shipment to correct errors caused by installation conditions or heat effects during molding operations. be.

In the end, as mentioned above, conventional platen parallelism adjustment is time-consuming and difficult for the user of the molding machine to adjust, or even after adjustment.
When the mold was clamped, it would go awry again due to backlash and other factors, making it difficult to ensure perfect parallelism adjustment.

Problems to be Solved by the Invention The present invention provides a parallelism adjustment method that can easily and completely adjust the parallelism between a fixed platen and a rear platen connected by tie bars in a mold clamping section of a molding machine. The task is to

Means for Solving the Problem A fixed platen, a movable platen, and a rear platen are provided, and the fixed platen and the rear platen are connected by a plurality of tie bars, and the movable platen is slidably attached to the tie bars, and the mold is clamped to the rear platen. This invention relates to mold clamping parts connected via a mechanism.

Each tie bar is provided with a distance adjustment mechanism between the fixed platen and the rear platen.

Measure the distance between the fixed platen and the rear platen at each location on each tie bar.

As a result of the measurement, either the maximum or minimum value of the obtained measurement value is fixed with respect to the other tie bar points,
The respective distance adjustment mechanisms are operated so that the distances between the rear platens match each other within their respective tolerances.

Next, a temporary mold clamping operation is performed.

This process is repeated until the distances between the fixed platen and the rear platen at each tie bar location after the temporary mold clamping operation match within the tolerance range.

The working distance adjustment mechanism adjusts the distance between the fixed platen and the rear platen at each of the plurality of tie bar locations.

By matching the distance between the fixed platen and the rear platen at other tie bar locations to either the maximum or minimum measured value, all the distance adjustment mechanisms in the tie bars of the above function can be adjusted in the same positive or negative direction. Operate.

The means of performing a temporary mold clamping operation and repeating it until the distance between the fixed platen and rear platen at each tie bar point after the temporary mold clamping operation matches within the tolerance range eliminates errors that occur during adjustment operations by the distance adjustment mechanism. do.

Embodiment FIG. 1 shows an injection molding machine having a mold clamping section 1 in which the present invention is implemented.

The mold clamping section 1 includes a fixed platen 2, a movable platen 3, and a rear platen 4.
are connected by four (plural) tie bars 5, and a movable platen 2 is slidably attached to the tie bars 5 and is connected to the rear platen 4 via a mold clamping mechanism 6.

The fixed platen 2 is fixed upright to the base 7, and the rear platen 4 is supported by a platen support 8 and can be moved slightly back and forth on the base for die-hide adjustment.

The rear end portion of each tie bar 5 is formed into a threaded portion 9 and projects rearward from the rear platen 4, and a tie bar nut 10 is screwed into this threaded portion 9. The tie bar nut 10 is rotatably supported on the rear surface of the rear platen 4, and a distance adjusting servo motor 11 is fixed to the side surface of the rear platen 4.
and an output gear 12 are connected by a timing belt 13 (FIG. 3). The distance adjusting servo motor 11 is equipped with a negatively operated brake 14, which brakes the motor shaft when the power supply is cut off.

Therefore, when the tie bar nut 10 is driven by the distance adjusting servo motor 11, the rear platen itself moves back and forth at the tie bar location due to the screw engagement with the threaded portion 9. That is, the structure consisting of the threaded portion 9, tie bar nut 10, servo motor 11, etc. forms a distance adjustment mechanism between the fixed platen and the rear platen at each tie bar location.

In Figure 3.4, numeral 15 is a laser measuring device and transmitter 1
6 and a receiver 17. This measuring device is commercially available.
The measured distance between the transmitter 16 and receiver 17 is A/
The D-converted signal is output to an NC device (numerical control device) 18 provided in the injection molding machine. In the figure, for convenience, the measurement results for the - tie bar locations are transmitted to the NC device 18, but the measurement results are transmitted for each tie bar location.

In addition to controlling the conventional molding operation in an injection molding machine, the NC device 18 also controls the distance adjusting servo motor 11 described above. Hereinafter, the control of the distance adjustment servo motor 11 will be mainly explained.

FIG. 5 shows the control structure in the NC device 18.
8, distance adjustment servo motor 11 and laser measuring device 1
Shows the relationship with 5.

The NC device 18 includes an NC microprocessor (hereinafter referred to as
CPU108 for the programmable machine controller (hereinafter referred to as PMC), and the CPU108 for the PMC has an R controller that stores sequence programs etc. that control the sequence operations of the injection molding machine.
OMI 13 and RAM used for temporary storage of data, etc.
106 is connected. The NC CPU 108 stores a management program that controls the entire injection molding machine.
, = servo interface 107 is a servo circuit 101 that drives and controls the servo motors for each axis such as ROMIII, injection, clamp, screw rotation, ejector, and injection unit, and the distance adjustment servo motor 11.
connected via. In FIG. 5, only the distance adjusting servo motor 11 and the corresponding servo circuit 101 are shown.

The servo circuit 101 is connected to an NC CPU 10 via a servo interface 107 when the servo motor 11 is driven.
8, the position command pulses input at predetermined intervals are cumulatively stored, and the feedback pulses input from the pulse coder of the servo motor 11 are subtracted to calculate the position deviation with respect to the current command position. Error register output as drive command and servo motor 11
The current rotational position of the servo motor 11 is calculated by cumulatively storing the feedback pulses input from the pulse coder of the servo motor 11.
That is, a current position storage register for detecting the current position of the moving member 14 is provided.

Further, 105 is a non-volatile shared RAM composed of bubble memory or CMOS memory, and a memory section for storing NC programs etc. for controlling each operation of the injection molding machine, and various setting values regarding molding conditions, etc.

It has a setting memory section that stores parameters and macro variables. 109 is a bus arbiter controller (hereinafter referred to as BA
C), the BAC1091: is the NC CPU10
8 and PMC CPU110° shared RAMI O5, input circuit 104. Each bus of the output circuit 103 is connected, and the BAC 109 controls the buses to be used.

A laser measuring device 15 is connected to the output circuit 103, and an NC
The distance between the fixed platen 2 and the rear platen 4 is measured at each tie bar location according to a measurement command from the NC CPU 108, and the measurement results are sent to the NC CPU via the input circuit 104.
108.

Further, 114 is a manual data input device with a CR7 display device (hereinafter referred to as CRT, 'MDI) connected to BAC 109 via operator panel controller 112.
It is now possible to display various setting screens and work menus on the CR7 display screen, and to input various setting data and select setting screens by operating various operation keys (soft keys, numeric keys, etc.). ing. In addition, 102
is a RAM connected to the NC CPU 108 via a bus and used for temporary storage of data.

In the above configuration, the NC device 18 uses the shared RAM 10
The PMC CPU 110 performs sequence control based on the NC program for controlling each operation of the injection molding machine stored in 5, the parameters for various molding conditions stored in the setting memory section, and the sequence program stored in ROM 3. From there, the NC CPU 108 distributes pulses to the servo circuits of each axis including the distance adjustment servo motor 11 of the injection molding machine via the servo interface 107 to control the injection molding machine.

In this embodiment, a program for "parallelism adjustment processing" for adjusting the distance at each tie bar location based on the measurement result by the laser measuring device 15 is stored in the shared RAM 105.

FIG. 1 is a flowchart outlining the "parallelism adjustment process" and shows the procedure for parallelism adjustment according to the method of the present invention.

This process is carried out to avoid a period in which a strong force is applied to the threaded surface of the tie bar nut 10 and the threaded portion 9 of the tie bar 5 due to the reaction force caused by the mold clamping force during lock-up, for example, immediately after the start of the 10-piece molding operation. , preferably when the movable platen 3 is at a stop position in the molding cycle during the ejection period.

Note that this process is executed as a process by the NC CPU 108, and indexes i=1.2, 3 are fixed at each tie bar location.
．． 4 is attached.

When parallelism processing is started, flag F is first initialized (step SL). In this process, the flag F is used to measure the distance between the fixed platen 2 and the rear platen 4 at each tie bar location, and then to determine whether the temporary mold clamping operation has been performed at least once. Further, the temporary mold clamping is a mold clamping operation performed to actually verify whether the distance between the fixed platen 2 and the rear platen 4 at each tie bar location has been corrected correctly.

The distance between the fixed platen 2 and the rear platen 4 is measured at each tie bar location (step 2).

This process is performed as a measurement process as shown in FIG. 1(a).

First, after initializing the index l (step 520), the index i is set to 1 (step 521), and it is determined whether i>4 (step 522). At first it is No, so the index i
A measurement command is issued to the laser measuring device 1 (denoted as K1) at 1 (step 523), and a wait is made for the measurement value L1 as the measurement result to reach the input circuit 104 (step 524). Then, when the measured value L1 is input, it is stored in the register R(1) of the shared RAM 105 (step 525), and then the process returns to step S21 where the index i=
2, issue a measurement command to the measuring instrument 2 in the same manner as above, obtain the measured value L2, and store this in the register R(2).

This is repeated, and the measured values R(1) to R(4) for each tie bar location are stored in the shared RAM 105. During this time, the determination in step S22 is always No.

Then, in step S25, the measured value R(4) is obtained and the process returns to step S21. When reaching step S22, i=5 and 4.
Therefore, the determination in step S22 is YES, and the measurement process ends.

Returning to the main routine in Figure 1, the above R(1) to R(
4) is searched for the shortest value R (min) (step S3).

This is performed as a shortest value search process as shown in FIG. 1(b).

After initializing index i and index n (step 530), each is set to i=1. Let n=1 and step 531),
It is determined which of the measured value R(1) stored in the shared RAM 1.05 and the same R(1) is larger (step 532). Since these are naturally equal, the process proceeds to step S33, where the index n is incremented by 1 (n=2), and the process proceeds to step 34, where it is determined whether the index n is 4 or more. Since the index is n2, the answer is No, and the process returns to step S32, where the measured values R(1) and R(2) are compared.

If R(1)≦R(2), repeat the same process as above to obtain the measured value R(1), R(3), R(4).
), and when the index n=5, step S3
Judgment number 4 is YES. The shortest value at this time is R(1)
It is. Therefore, the shortest value R (
1) into register R(min) (step 836
) Terminate this process. In the above, R(1)≧R(
2), the judgment in step S32 is YES, so the process moves to step 35, increments the index i by 1 (i=2), returns to step 32, and calculates the same value as the measured value R(2). are compared. And R(2)≦R(1
), the process moves to step S33, and if No, the process moves to step S35, and the same process is repeated until n=5, and the last remaining measured value R(i) on the left side is the shortest value. . That is, as long as the condition of step S32 is satisfied, the right side is exchanged and compared, and when the condition no longer holds, the left side is exchanged. Moreover, at the stage of mutual exchange and comparison, R(i) = R(n) and YE
Since it is switched to the S side and n=5, it is possible to compare all measured values and search for the shortest value. Therefore,
Similar to the above, the shortest value R(i) found in this way
is placed in the register R(min) (step 836), and this process ends.

Return to the main routine and calculate the difference (IR(i)R(n+in) between the shortest value R(min) and other measured values R(i).
) l) are all pre-set allowable values ε (approximately 15/100 mm at a mold clamping force of 300 tons, which varies depending on the magnitude of the mold clamping force. Input from MDI 114, shared R
stored in AMIO3) is within the range (step S4). This judgment is made as shown in Figure 1 (c),
The measured values R(1) to R(4) are sequentially investigated using the index i (step 840.41), and if there is one that exceeds the tolerance value ε on the way, the process immediately moves to step S5. ing. If there is no value exceeding the allowable value ε, the process moves from step S41 to step S6 of the main routine when i=5, and it is determined whether the flag F=1. That is, it is determined whether the state in which there is no material exceeding the allowable value ε occurs after temporary mold clamping has been performed. In this case, since the flag F=0, the process moves to step S7 and temporary mold clamping is performed. On the other hand, in the above step S5
When moving to , each tie bar location (i = 1°2, 3.
4) The distance adjustment servo motor 11 is sequentially (R
A command to move by (i) -R (min)) and pulse distribution are performed, and the motors are driven via the servo interface 107 and the servo circuit 101, respectively. Note that the rotation of the tie bar nut 10 due to this drive is slight, less than one pitch in the threaded portion 9, and the rotation of each tie bar 5 is small.
It is possible to rotate them individually. After each rotation, a brake 14 is activated to prevent the tie bar nut 10 from drifting. Next, temporary mold clamping is performed (step S
7), set the flag F=1 (step S8), return to step S2 again, carry out the above measurement, and search for the shortest value (step S8).
3) Determining whether the value is within the allowable value range (step S4)
I do. As long as the determination in step S4 is NO, the above cycle is repeated, and when the determination is YES, the process moves to step S6. At this time, since F=1, step S
If the judgment in step 6 is YES, the process moves to step S9, where the current length of each tie bar 5 and the current rotational position of each distance adjustment servo motor 11 are taught to the NC device 18 as the origin, and this parallelism processing is completed. do.

Thereafter, the NC device 18 performs die-hide adjustment (driving each distance adjustment servo motor 11 by the same amount) based on this origin.

As described above, the distance between the fixed platen 2 and the rear platen 4 is made equal at each tie bar location, and the parallelism between these platens is maintained.

As a result, the distribution of clamping force on the parting surface of the mold becomes even.

At that time, the distance between the fixed platen 2 and the rear platen 4 is measured for each tie bar location, so the inclination of the rear platen 4 can be accurately determined, and the adjustment values for other tie bar locations can be determined based on the shortest value. So, tie bar nut 10
The direction of rotation is the same for all tie bars 5, and errors caused by backlash between the tie bar nut 10 and the threaded portion 9 are eliminated during adjustment. If a laser measuring device is used to measure the distance, the measurement can be easily performed, and the entire distance can be measured to obtain an accurate measurement value.

Furthermore, since the temporary mold clamping is performed after the distance is adjusted as described above, the parallelism can be adjusted in accordance with the actual molding operation.

Then, as in the embodiment, by disposing a distance adjusting servo motor 11 at each tie bar location, it is possible to electrically and automatically adjust the parallelism.

The above is an example.

The invention can also be incorporated into the cycle of a molding operation. In that case, a defective product may be produced in the temporary mold clamping step, but the temporary mold clamping is performed only about two times and no particular problem occurs. Further, the time required for the distance adjustment servo motor to be driven and the distance between the fixed platen and the rear platen to be corrected is actually about 1 second.

The reference value for correcting the distance between the fixed platen and the rear platen may be the longest distance.

The distance measuring device is not limited to a laser measuring device.

Note that each tie bar nut can also be rotated manually.

Effects of the Invention Since the distance adjustment mechanism for each tie bar can be driven or manually operated, the distance between the fixed platen and the rear platen can be easily adjusted.

The above distance adjustment is practical and accurate.

[Brief explanation of drawings]

Figure 1 is a flow diagram of parallelism processing, Figure 1 (a). (B) and (C) are flowcharts of partial processing in the above parallelism processing, Figure 2 is a front view, Figure 3 is a front view of the fixed platen seen from the rear, Figure 4 is a plan view, and Figure 5. is a control block diagram. 2...Fixed platen, 4...Rear platen, 5...
Tie bar, 9... Threaded portion, 10... Tie bar nut, 11... Distance adjustment servo motor, 15... Laser measuring device, 18... NC device. Figure 1 (a) Figure 1 (b) Procedural amendment (method) February 4, 1991

Claims (1)

[Claims] The device includes a fixed platen, a movable platen, and a rear platen, the fixed platen and the rear platen are connected by a plurality of tie bars, and the movable platen is slidably attached to the tie bars and is connected to the rear platen via a mold clamping mechanism. Regarding the mold clamping section, each tie bar is equipped with a distance adjustment mechanism between the fixed platen and the rear platen, and the distance between the fixed platen and the rear platen is measured at each location on each tie bar. Each distance adjustment mechanism is operated so that the distance between the fixed platen and the rear platen with respect to the other tie bar points matches one of the minimum values within the tolerance range, and then a temporary mold clamping operation is performed to adjust this to the specified value. A method for adjusting the parallelism of a platen in a molding machine, comprising repeating the process after the preliminary mold clamping operation until the distances between the fixed platen and the rear platen at each of the tie bar locations match within a tolerance range.