JP6957378B6 - Hollow molding method and hollow molding machine - Google Patents

Description

The present invention relates to a hollow molding method and a hollow molding machine for centering a center position of a counter plate of a molding die and a shaft center of a driving nozzle in hollow molding.

In a general hollow molding machine, a synthetic resin parison melted and discharged from a head connected to an extruder is introduced into a molding die, the molding die is closed by a mold clamping device, the parison is sandwiched, and then the cutter is used. Then, the mold clamping device is transferred to the driving position, the driving nozzle for blowing compressed air of the driving device is lowered to the parison and driven, and the compressed air is blown into the parison from the tip of the driving nozzle. The parison is inflated and brought into close contact with the cavity of the molding die to obtain a hollow molded product.

When the driving nozzle descends into the parison in the molding die and drives it, the inside of the tapered portion whose diameter is reduced from the upper side to the lower side of the counter plate located at the nozzle driving inlet of the molding die. The parison is cut in a shearing manner by being sandwiched between the peripheral edge and the outer peripheral edge of the cutting sleeve located at the tip of the driving nozzle.

At the time of such driving, those shown in Patent Document 1 and Patent Document 2 are known regarding the alignment, that is, the centering of the axis of the cutting sleeve of the driving nozzle and the center position of the tapered portion of the counter plate.

Explaining what is shown in Patent Document 1, as shown in FIG. 2 of the document, an image pickup device is placed at the center position of a tapered portion of a counter plate of a molding die, and compressed air is injected by the image pickup device. Nozzle axis position image information is taken out, calculated and processed by the image processing device, the displacement or concentricity of the driving nozzle axis is calculated and displayed on the display device, and the displacement or concentricity is used. It was a centering method in which the shaft center position of the driving nozzle was adjusted to the center position of the tapered portion of the counter plate.

Explaining what is shown in Patent Document 2, as shown in FIG. 1 of the document, fluid is blown toward the driving nozzle from at least four sides facing each other in the direction orthogonal to the driving nozzle 1, and each back pressure or flow rate It was a centering method in which the shaft center position of the driving nozzle was manually adjusted so that these values became constant.

Further, regardless of these methods, there is also a conventional method in which the operator of the molding machine actually performs centering by visual confirmation.

Japanese Patent No. 4242242 Japanese Patent No. 3352806

In the centering method of Patent Document 1 described above, a coordinate axis table provided with the driving nozzle grip portion and movable in the intersecting biaxial directions, an actuator for moving the coordinate axis table in the intersecting biaxial directions, and a center position. Is placed so as to match the center position of the tapered portion of the counter plate of the molding mold, and the image pickup device for extracting the image information regarding the center position of the drive nozzle and the drive nozzle taken out by the image pickup device. An image processing device that calculates and processes image information about the center position to calculate the degree of displacement or concentricity of the center position of the driving nozzle with respect to the center position of the tapered portion of the counter plate, and the calculated degree of displacement or concentricity. It is necessary to provide a control unit for moving the coordinate axis table by outputting the nozzle to the actuator as a drive signal, which may increase the cost.

Further, in the centering method of Patent Document 2 described above, it is difficult to guarantee the accuracy of installing the air ejection center of the driving centering device at the center of the counter plate of the mold, and air is supplied due to the outer diameter of the nozzle. The spouting annular plate must be replaced. In addition, there is a problem that it takes time to set the centering device at the time of centering work of driving.

Further, in the above-mentioned conventional method that does not depend on these, the accuracy of centering is expected to vary depending on the proficiency level of the operator, and there is a possibility that the time until the completion of centering also varies.

The present invention is intended to solve the problem of such a conventional configuration, and automatically efficiently centering the center position of the counter plate of the molding die and the axis of the driving nozzle. Moreover, the purpose is to realize a hollow forming method and a hollow forming machine which are intended to be appropriately performed.

In order to achieve the above object, the present invention reduces the diameter of the molding die from above to below when blowing the compressed fluid from the driving nozzle into the parison that is hung from the die head and stored in the molding die. In the centering method in which the axis of the driving nozzle is aligned with the axis of the tapered portion of the counter plate having the tapered portion, the driving nozzle is previously installed at a reference position and the driving is performed. The position of the radial end face of the nozzle is detected by the laser sensor, and the driving nozzle is lowered with respect to the reference position information of the radial end face of the driving nozzle detected by the laser sensor, and the counter plate is said. The misalignment of the axis of the driving nozzle is detected from the position information of the radial end face of the driving nozzle detected by the laser sensor when abutting on the tapered portion, and then the position of the die head is obtained from the misalignment information. This is a hollow molding method in which the stop position of the molding die that moves between the position and the position of the driving nozzle is corrected and centered.

The position of the radial end surface of the driving nozzle is detected by a laser sensor, and the driving nozzle is lowered with respect to the reference position information of the radial end surface of the driving nozzle to hit the tapered portion of the counter plate. The positional deviation of the axis of the driving nozzle is detected from the position information of the radial end surface of the driving nozzle detected by the laser sensor when in contact with the driving nozzle, and the radial end surface of the driving nozzle before and during driving is detected. Judge whether the position difference of is zero or not. If it is not zero, the stop position, that is, the driving position of the slide of the mold clamping device is corrected and moved in consideration of the correction setting described later. Then, the execution is repeated until the positional difference becomes zero.

The second problem-solving means is a taper whose diameter is reduced from the upper side to the lower side in the molding die when the compressed fluid is blown from the driving nozzle into the parison that is hung from the die head and stored in the molding die. A laser sensor for detecting the position of the radial end face of the driving nozzle is provided in a hollow forming machine that matches the axis of the driving nozzle with respect to the center position of the tapered portion of the counter plate having the portion, and the laser is provided. When the driving nozzle is lowered and abuts on the tapered portion of the counter plate with respect to the reference position information of the radial end surface of the driving nozzle installed at the reference position detected by the sensor, the laser sensor detects it. The molding die that detects the positional deviation of the axis of the driving nozzle from the position information of the radial end surface of the driving nozzle and moves between the position of the die head and the position of the driving nozzle from the position deviation information. It is a hollow forming machine provided with a control device for correcting the stop position, that is, the driving position.

The action of the first problem-solving means is as follows. That is, the driving nozzle is installed at a reference position in advance, the position of the radial end face of the driving nozzle is detected by the laser sensor, and the radial end face of the driving nozzle detected by the laser sensor. The axis of the driving nozzle is based on the position information of the radial end surface of the driving nozzle detected by the laser sensor when the driving nozzle is lowered with respect to the reference position information and comes into contact with the tapered portion of the counter plate. The misalignment of the core is detected, and it is determined whether or not the positional difference between the radial end faces of the driving nozzle before and during driving is zero. If it is not zero, the stop position, that is, the driving position of the slide of the mold clamping device is corrected and moved in consideration of the correction setting described later. The stop position of the molding die can be corrected until the misalignment becomes zero, and the centering of the driving position can be objectively determined without depending on the proficiency level of the operator.

The action of the second problem-solving means is as follows. That is, a laser sensor for detecting the position of the radial end surface of the driving nozzle is provided in advance, and the driving is performed with respect to the reference position information of the radial end surface of the driving nozzle installed at the reference position detected by the laser sensor. When the nozzle is lowered and comes into contact with the tapered portion of the counter plate, the positional deviation of the axis of the driving nozzle is detected from the position information of the radial end face of the driving nozzle detected by the laser sensor. It is determined from the misalignment information whether or not the misalignment is zero. If it is not zero, the stop position, that is, the driving position of the slide of the mold clamping device is corrected and moved in consideration of the correction setting described later. Then, the execution is repeated until the positional difference becomes zero. A hollow molding machine equipped with a control device that corrects the stop position of the molding die until the misalignment becomes zero and can objectively determine the centering of the driving position without depending on the proficiency level of the operator. be.

As described above, in the hollow molding method and the hollow molding machine of the present invention, the position of the radial end face of the driving nozzle is detected by the laser sensor, and the radial end face of the driving nozzle detected by the laser sensor. The axis of the injection nozzle is based on the position information of the radial end surface of the injection nozzle detected by the laser sensor when the injection nozzle is lowered with respect to the reference position information and comes into contact with the tapered portion of the counter plate. The misalignment of the core is detected, and the execution is repeated until the position difference becomes zero, and the stop position, that is, the driving position of the molding die is automatically corrected efficiently and appropriately to perform centering, and the molding process is performed. It is a hollow forming machine provided with a control device capable of achieving efficiency improvement.

The front view of the hollow molding machine which shows the embodiment of this invention. The side view of the hollow molding machine shown in FIG. The front view which enlarged the driving nozzle part of the hollow molding machine shown in FIG. The side view which enlarged the driving nozzle part of the hollow molding machine shown in FIG. The plan view which shows the laser sensor shown in FIG. The block diagram which shows the control apparatus of the hollow forming apparatus of FIG. FIG. 6 is a processing flowchart of the control device shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5.

As shown in FIGS. 1 and 2, the hollow molding apparatus according to the embodiment of the present invention is an extruder for which the resin composition is melted and extruded as an operating portion for molding, and the tip of the extruder is omitted. It is provided with a die head 1, a parison cutting device (not shown), a molding die 2, a driving device 3, a mold clamping device 4, and the like, which are connected to the die head 1.

The extruder is provided with a hopper 7 for charging the resin composition and a screw (not shown) for transferring, kneading, melting, and discharging the resin composition inside the extruder.

As shown in FIG. 1, the die head 1 is for a large number of heads. The resin composition melted by the extruder is supplied from the extruder to the die head 1 to form a tubular parison.

The parison cutting device cuts the upper part of the tubular parison hanging from the die head 1, and includes a cutter holder having an electric heating cutter.

As shown in FIG. 2, the molding die 2 is composed of a pair of half-split dies 2a and 2b, and a cylindrical parison is inserted into each of these half-split dies to form a hollow molded product. The cavities 25, 25 (see FIG. 3) are formed. As shown in FIGS. 3 and 4, a counter plate 26 is formed on the upper portions of the cavities 25 and 25 with which the cutting sleeve 8a of the driving nozzle 8 abuts when the driving nozzle 8 described later is driven. .. The counter plate 26 is made of hardened steel and has a tapered portion 26a whose diameter is reduced from the upper side to the lower side.

The molding die 2 is provided by the molding die moving device 5 between the position directly below the die heads 1 and 1, that is, the position where the parison is introduced into the mold and the position directly below the driving nozzles 8 and 8 of the driving device 3. It can be reciprocated in the horizontal direction.

As shown in FIGS. 1 and 2, the driving device 3 is inserted into the tubular parison above the left and right cavities of the molding die 2 to blow compressed air, which is a compressed fluid, into the left and right. The driving nozzles 8 and 8 and the driving nozzle driving device 9 for raising and lowering the driving nozzles 8 and 8 are provided. The driving nozzle drive device 9 includes a variable type driving device driving servomotor 9a connected to a control device 50 described later based on FIG.

As described above, the driving nozzle 8 abuts the cutting sleeve 8a on the tapered portion 26a of the counter plate 26 formed in each of the half-split molds 2a and 2b at the time of driving, and shears the unnecessary upper portion of the parison. It is a thing. Compressed air is supplied to the driving nozzle 8 from an air source (not shown), is supplied into the left and right cavities of the molding die 2, and the compressed air is blown into the tubular parison. ..

The shaft cores of the driving nozzles 8 and 8 are always located on an extension of the parting line L (see FIG. 2) of the molding die 2 to be used. The parting line L and its extended line are mechanically set so as to always be on the same line even if the molding die used is changed depending on the product to be molded.

As shown in FIGS. 1 and 2, the mold clamping device 4 molds the half-split molds 2a and 2b of the molding mold 2 in a pair of horizontal directions arranged at predetermined intervals in the horizontal direction. The extending rails 12 and 12, the front platen 10 and the rear platen 11 movably provided on the rails 12 and 12 at predetermined intervals, and the parting line L of the molding die 2 are inserted through the platens 10 and 11. Left and right reverse lead ball screws 13 that move in synchronization with each other in the approaching and separating directions, convex locking portions 14 provided on both sides of the platens 10 and 11, and concave locking that grips the corresponding convex locking portions. The ball screw 16 coupled to the concave locking portion 15 so that the portion 15 and the concave locking portion 15 holding the convex locking portion 14 can be pulled, and the left and right reverse leads located on the back side of the rear platen 11. It includes a mold clamping slide servomotor 17 for sliding movement of the platens 10 and 11 connected to the ball screw 13, and a servomotor (not shown) located behind the rear platen 11 to drive the ball screw 16. .. The front platen 10 is detachably attached to the half-split type 2a, and the rear platen 11 is also detachably attached to the half-split type 2b.

The left and right ball screws 16 and 16 are provided with pulleys 18 and 18 via thrust bearings (not shown), respectively, and these pulleys 18 and 18 are connected to a servomotor (not shown) via an endless belt 19 and a speed reducer 20. doing.

The molding die moving device 5 has a pair of rails 30 and 30 in the direction LE (see FIG. 1) in which the parting line L shown in FIG. 2 is orthogonal to the paper surface, so that the molding die 2 is moved. A ball screw (not shown) for reciprocating the first slide base 31 on which the molding die 2 is placed on the pair of rails 30 and 30 and a servomotor 33 in which one end of the ball screw is coupled and rotationally driven. It is equipped with.

The pair of rails 30 and 30 are fixedly provided on the second slide base 35. The second slide base 35 can also be moved in a direction orthogonal to the parting line L via the engaging portions 38, 38 that engage with the pair of rails 37, 37 provided on the base 36. It has become.

In the above-mentioned hollow molding apparatus, a laser sensor 40 is arranged on one of the driving nozzles 8 and 8 as shown in FIGS. 3 to 5. The laser sensor 40 includes a light emitting unit 40a and a light receiving unit 40b, and is arranged so that the laser light emitted from the light emitting unit 40a covers the radial end face of the driving nozzle. It is preferable to use a laser sensor 40 having a measurement accuracy of 0.01 mm to 0.001 mm and a position detection capability.

The laser sensor 40 emits laser light from the light emitting unit 40a toward the driving nozzle 8, and as shown in FIG. 5, the light receiving unit 40b detects and detects the position information of the radial end face of the laser light. The generated position information is processed by the control device 50 as shown in FIG.

In the control device 50, the programmable logic controller (PLC) 51 receives the centering start command from the connected operation display panel 60, and sends the centering start command to the driving servomotor 9a via the driving servo amplifier 52 according to the flowchart described later. It is designed to drive a motor. Further, the control device 50 receives the position information of the radial end face of the driving nozzle 8 detected by the laser sensor 40, processes this information by the programmable logic controller 51 according to the flowchart described later, and processes the processing signal. The mold clamping slide servomotor 17 is driven via the mold clamping slide servo amplifier 53.

An operation display panel 60 is also connected to the control device 50. The operation display panel 60 can input information necessary for operating the flowchart described later.

The processing in the programmable logic controller (PLC) 51 of the control device 50 is carried out according to the flowchart as shown in FIG. That is, in step S1, the operator selects the "driving centering mode" on the operation display panel 60. In step S2, the operator performs "(1) descending stroke of the driving nozzle 8" and "(2) current value at the completion of lowering of the driving nozzle 8" on the "driving centering setting screen" of the operation display panel 60. , And each setting value of "(3) Correction setting". The correction value of the correction setting is multiplied by the difference between the radial end face position of the nozzle body in the descent stroke setting of the driving nozzle 8 and the radial end face position of the nozzle body at the descent completion position of the driving nozzle 8. A / which is a value and is divided by the support position of the driving nozzle 8 and the height A of the cutting sleeve 8a shown in FIG. 3 and the height B of the support position of the driving nozzle 8 and the mounting position of the laser sensor 40. The value of B (unit:%).

The descending stroke means a stroke sufficient for the driving nozzle 8 to pass through the laser sensor 40 and to detect the position of the radial end surface of the body of the driving nozzle 8 by the laser sensor 40. The current value at the time of completion of the descent, in which the measured value at the descent stroke position is the reference position, is such that the driving nozzle 8 further descends and the cutting sleeve 8a hits the tapered portion 26a of the counter plate 26 of the molding die 2. It means the current value at the time of contact. The correction value is a correction value for the detected deviation amount when the detection position of the driving nozzle 8 of the laser sensor 40 and the contact position between the counter plate 26 and the cutting sleeve 8a are different.

The correction value is due to the fact that when the driving nozzle 8 comes into contact with the counter plate 26, the driving nozzle 8 is tilted if there is a misalignment, and the support position of the driving nozzle 8 and the height A of the cutting sleeve 8a , Set the value (unit%) of A / B divided by the height B of the support position of the driving nozzle 8 and the mounting position of the laser sensor 40, and set the position of the die head 1 and the driving by the mold clamping slide servomotor 17. The correction amount of the stop position, that is, the driving position of the molding die 2 that moves between the positions is calculated.

Then, as shown in step S3, the operator presses the "centering start key" on the operation display panel 60. Then, it is processed as follows by the setting program. That is, as shown in step S4, the driving nozzle 8 descends to the descending stroke set position at a low speed.

As shown in step S5, when the driving nozzle 8 is lowered, the laser sensor 40 detects the reference position information of the radial end surface of the body of the driving nozzle 8.

As shown in step S6, the driving nozzle 8 is further lowered to reach the lowering completion position at a low speed. That is, it is said that the current value when the cutting sleeve 8a of the driving nozzle 8 comes into contact with the counter plate 26 of the molding die 2 is detected and the current value set above is reached.

At this time, as shown in step S7, the position information of the radial end face of the body of the driving nozzle 8 is detected by the laser sensor 40.

As shown in step S8, the driving nozzle 8 rises to the start position and stops.

On the other hand, as shown in step S9, the control device 50 determines whether or not the positional difference between the radial end faces of the body of the driving nozzle 8 before and during driving is zero. If it is not zero, as shown in step S10, the stop position, that is, the driving position of the slide of the mold clamping device 4 is corrected and moved in consideration of the above-mentioned correction setting. Then, the execution of the above-mentioned steps S4 to S9 is repeated.

If YES in step S9, the "driving centering mode" ends (step S11).

Next, a hollow molding method using a hollow molding machine according to the above-described embodiment will be described.

First, in hollow molding, centering of the shaft core of the driving nozzle 8 and the center position of the tapered portion 26a of the counter plate 26 of the molding die 2 is performed according to each step shown in FIG.

As shown in FIG. 7, in step S1, the operator selects the “driving centering mode” on the operation display panel 60.

In step S2, the operator performs "(1) descending stroke of the driving nozzle 8" and "(2) current at the completion of lowering of the driving nozzle 8" on the "driving centering setting screen" of the operation display panel 60. Enter each setting value of "Value" and "(3) Correction setting".

Then, as shown in step S3, when the operator presses the "centering start key" of the operation display panel 60, the driving nozzle 8 descends to the descending stroke setting position at a low speed as shown in step S4.

As shown in step S5, when the driving nozzle 8 is lowered, the laser sensor 40 detects the position information of the radial end surface of the body of the driving nozzle 8.

As shown in step S6, the driving nozzle 8 is further lowered to reach the lowering completion position at a low speed.

At this time, as shown in step S7, the position information of the radial end face of the body of the driving nozzle 8 is detected by the laser sensor 40.

As shown in step S8, the driving nozzle 8 rises to the start position and stops.

On the other hand, as shown in step S9, the control device 50 determines whether or not the positional difference between the radial end faces of the body of the driving nozzle 8 before and during driving is zero. If it is not zero, as shown in step S10, the stop position, that is, the driving position of the slide of the mold clamping device 4 is corrected and moved in consideration of the above-mentioned correction setting. Then, the execution of the above-mentioned steps S4 to S9 is repeated.

If YES in step S9, the "driving centering mode" ends as shown in step S11.

An example of operation confirmation in the centering step is shown below.

Table 1 will be described below. At the start of the operation check in the centering step, the slide current value of the mold clamping device is shifted by 0.86 mm in the die head direction (left direction in FIG. 1). The reason for the deviation of 0.86 mm is to create a misaligned state in advance and to confirm that the centering operation is automatically repeated. If the measured value at the lowering completion position of the driving nozzle 8 is smaller than the measured value at the lowering stroke setting position of the driving nozzle 8, it is moved in the driving position direction (right direction in FIG. 1). If the measured value at the lowering completion position of the driving nozzle 8 is larger than the measured value of the descending stroke set position of the driving nozzle 8, move it toward the die head (left direction in FIG. 1).

In the first measurement, the difference in measured values of 0.38 mm was multiplied by a correction value of 200% to determine the amount of movement of the slide of the mold clamping device to be 0.76 mm. It shows that the current value of the slide of the mold clamping device is 0.10 mm. That is, as described in the remarks column, it is 0.10 mm obtained by subtracting 0.76 mm from the above confirmation start slide position of 0.86 mm. The same applies to the second measurement. By multiplying the measurement difference of 0.02 mm by the correction value of 200%, the amount of movement of the slide of the mold clamping device is determined to be 0.04 mm, and after moving to the left in FIG. It shows that the current value of the slide of the mold clamping device is 0.14 mm. That is, as described in the remarks column, it is 0.14 mm obtained by adding 0.04 mm from the first slide position of 0.10 mm.

From the third time onward, the movement is repeated based on the measurement difference and the movement direction. Since the measurement difference became 0.00 mm at the 10th time, the centering mode was completed.

After the centering step is completed, the molten synthetic resin extruded from the extruder (not shown) of the hollow molded product to the die head 1 is discharged as two parisons through the resin passage in the die head 1 and hangs down. These parisons enter the mold 2 which has been opened as shown in FIG. 1, the mold 2 closes the mold and holds the parison, and the upper part of the parison is cut by a cutter such as a hot cutter (not shown). And make it internal in the molding die 2.

Subsequently, the molding die 2 is moved to the driving device 3, and the two parisons contained in the molding die 2 are positioned directly under the two driving nozzles 8 of the driving device 3, and are placed in each parison. Each driving nozzle 8 is lowered and driven, compressed air is blown into the parison P from the driving nozzle 8, each parison is enlarged and brought into close contact with the cavity 25 of the molding mold 2 and blow-molded into a hollow molded product. do.

The hollow molded product is suspended from the driving nozzle 8 together with the upper burrs generated when the molding die 2 opens the mold, moves to the bottom of the die head 1 again, and drives the driving nozzle 8.

At the same time that the molding die 2 closes the mold and sandwiches the parison, the hollow molded product suspended from the driving nozzle 8 is gripped by a product holder (not shown), and after gripping, the driving nozzle 8 rises. At this time, the top burrs are removed.

Then, the hollow molded product held by the product holder is transferred to the outside of the molding apparatus at the same time as the mold opening after the blowing is completed.

As described above, according to the present embodiment, the effect that the centering of the driving nozzle 8 can be automatically and appropriately performed can be obtained.

2 ... Molding mold 3 ... Driving device 4 ... Molding device 5 ... Molding mold moving device 8 ... Driving nozzle 8a ... Cutting sleeve 25 ... Cavity 26 ... Counter plate 26a ... Tapered part 40 ... Laser sensor 50 ... Control device

Claims (2)

The taper of the counter plate having a tapered portion whose diameter is reduced from the upper side to the lower side in the molding die when the compressed fluid is blown from the driving nozzle into the parison hanging from the die head to the molding die and stored. In centering to match the axis of the driving nozzle with the axis of the part.
Install the driving nozzle at the reference position in advance.
The position of the radial end face of the driving nozzle is detected by the laser sensor, and the position is detected.
The hitting detected by the laser sensor when the driving nozzle is lowered and abuts on the tapered portion of the counter plate with respect to the reference position information of the radial end surface of the driving nozzle detected by the laser sensor. The misalignment of the axis of the driving nozzle is detected from the position information of the radial end face of the driving nozzle.
Next, a hollow molding method comprising correcting the stop position of the molding die that moves between the position of the die head and the position of the driving nozzle from the misalignment information. The taper of the counter plate having a tapered portion whose diameter is reduced from the upper side to the lower side in the molding die when the compressed fluid is blown from the driving nozzle into the parison hanging from the die head to the molding die and stored. In a hollow molding machine that aligns the axis of the driving nozzle with the center position of the portion.
A laser sensor for detecting the position of the radial end face of the driving nozzle is provided.
When the driving nozzle is lowered and abuts on the tapered portion of the counter plate with respect to the reference position information of the radial end face of the driving nozzle installed at the reference position detected by the laser sensor, the laser sensor causes the driving nozzle to lower. The molding that detects the positional deviation of the axis of the driving nozzle from the detected position information of the radial end surface of the driving nozzle and moves between the position of the die head position and the position of the driving nozzle from the position deviation information. A hollow forming machine characterized by being provided with a control device for correcting the stop position of the mold.

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