JP2015047773A - Method and device for cutting parison - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for cutting a parison in which ultrasonic vibration is applied to a cutter edge for cutting a parison, thus the generation of side face friction between the cutter edge and the cut surface of the parison is prevented.SOLUTION: Provided is a method and a device for cutting a parison, in which a parison (3) discharged from a cross head (1) is press-cut with a cutter edge (2) applied with ultrasonic vibration and capable of gear change. Further, in the cutter edge (2), upon cut-in and cut-out to the parison (3), the cutting speed is made higher than the cutting speed of the cutter edge (2) upon the cut-in and the cut-out.

Description

  The present invention relates to a parison cutting method and apparatus, and more particularly to a novel improvement for horizontally cutting a parison under a state in which ultrasonic vibration of a cutter blade is applied.

Examples of this type of parison cutting method and apparatus conventionally used include the configuration disclosed in Patent Document 1 shown in FIG. 4 and the configuration shown in FIG. 6 that does not disclose the literature name.
That is, what is indicated by reference numeral 2 in FIG. 4 is an electric heating type cutter blade provided in the cutter holder 2a, and a follower 20 having a rack 20b is provided on the support portion 2b of the cutter holder 2a. .

A pinion 22 is meshed with the rack 20b, and a control unit 23 is connected to the servo motor 21 for driving the pinion 22 via a rotating shaft 21a.
The control unit 23 incorporates a preset program. The servo motor 21 is servo-driven by this program, and is discharged from a cross head (not shown) by a cutter blade 2 reciprocating in the direction of arrow A. Is configured to be cut in the horizontal direction.
In particular, in this method, since the motor 21 can be program-controlled through the control unit 23, the cutting speed can be easily changed, and constant speed cutting, cutting with gradually changing speed from high speed to low speed, Conditions such as cutting from low speed to high speed can be freely set, so that an ideal circular cut surface can always be obtained regardless of the material, diameter, etc. of the parison.

JP-A-5-69474

Since the conventional parison cutting method and apparatus are configured as described above, the following problems exist.
That is, as shown in FIGS. 5A to 5C, when the parison discharged from the crosshead is cut in the cutting direction with an electric heating cutter, when the parison is pushed, actually (B) As in the state, friction force, that is, side friction is generated between the cutter blade and the cut surface of the parison, the parison is rubbed by this side friction, the parison is stretched by this rubbing, the cut end is not flat, As shown in (C), it was a corrugated cut.
In addition, this is not the case with the above-described electric heat cutter, and the same applies to, for example, a normal cutter blade.
In addition, since the operation of the cutter blade is driven by a motor, the speed can be changed, but no proposal has been made as to what part of the parison should be cut at what speed.
Moreover, although patent documents etc. are not disclosed, as shown in FIG. 6, when the cutter blade 2 that pushes out the parison 3 discharged from the discharge port 1 a of the crosshead 1 in the horizontal direction is cut off, this cutter blade 2. Even if the blade is extremely sharp, if the extrusion speed is relatively slow, the cut surface 3a of the parison 3 is inclined downward to the right, and the waste part of the parison increases during hollow molding. It was.

  The present invention has been made to solve the above-described problems, and in particular, by applying ultrasonic vibration to the cutter blade for cutting the parison, between the cutter blade and the parison when cutting the parison. A parison cutting method that reduces frictional force, eliminates friction caused by the friction, flattens the shape of the parison cutting surface, and sets the optimum cutting speed or changes the speed depending on the parison cutting site. And an apparatus.

  The parison cutting method according to the present invention is a method of pressing a parison discharged from a cross head with a variable-speed cutter blade provided with ultrasonic vibration, and the cutter blade is cut into the parison. When cutting from the parison, the cutting speed of the cutter blade between the cutting and cutting is faster than the cutting speed of the cutter blade, and the ultrasonic vibration is a method of 30 kHz or more. The cutter blade drive mechanism for driving the cutter blade is driven by a speed command from a computing unit, and the computing unit is operated at a cutting speed reaching position, a cutting end position, an internal cutting speed reaching position, and an internal cutting. By setting the end position, cutting speed arrival position, cutting end position, cutting speed, internal cutting speed, cutting speed, the cutter blade automatically The cutter blade is driven based on the created cutter blade speed profile, and an ultrasonic converter connected to an ultrasonic oscillator is connected to one end of the cutter blade, Between the rod of the cutter blade drive mechanism and the ultrasonic converter is a method connected via a vibration transmission suppressing member, and the parison cutting device according to the present invention, the parison discharged from the crosshead, The cutter blade is configured to be cut with a variable-speed cutter blade provided with ultrasonic vibration, and the cutter blade is cut into the parison and cut out from the parison. And the ultrasonic vibration is set to 30 kHz or more. The cutter blade driving mechanism for driving the cutter blade is driven by a speed command from a computing unit, and the computing unit is operated at a cutting speed reaching position, a cutting end position, and an internal cutting speed reaching position. By setting the internal cutting end position, the cutting speed arrival position, the cutting end position, the cutting speed, the internal cutting speed, and the cutting speed, a cutter blade speed profile is automatically created, and the created cutter blade speed profile The cutter blade is driven on the basis of one of the cutter blades, and an ultrasonic converter connected to an ultrasonic oscillator is connected to one end of the cutter blade, and between the rod of the cutter blade drive mechanism and the ultrasonic converter The configuration is such that they are connected via a vibration transmission suppressing member.

Since the parison cutting method and apparatus according to the present invention are configured as described above, the following effects can be obtained.
In other words, the friction force between the cutter blade and the parison can be reduced by pressing the parison discharged from the crosshead with a variable-speed cutter blade to which ultrasonic vibration is applied. The rubbing of the parison can be eliminated, and the shape of the cut surface of the parison can be made flat.
In addition, the cutter blade is configured to be faster than the cutting speed of the cutter blade between the cutting time and the cutting time at the time of cutting into the parison and at the time of cutting out from the parison. When cutting into the parison and when cutting out from the parison, the cutter blade is accelerated and cut, so that the parison can be cut without being stretched.
Moreover, the said ultrasonic vibration can reduce the frictional force between a cutter blade and a parison by being 30 kHz or more.
The cutter blade driving mechanism for driving the cutter blade is driven by a speed command from a computing unit, and the computing unit is at a cutting speed reaching position, a cutting end position, an internal cutting speed reaching position, and an internal cutting end. By setting the position, cutting speed arrival position, cutting end position, cutting speed, internal cutting speed, and cutting speed, a cutter blade speed profile is automatically created, and the cutter blade based on the created cutter blade speed profile Is driven, the speed control of the cutter blade can be made constant.
Also, an ultrasonic converter connected to an ultrasonic oscillator is connected to one end of the cutter blade, and the rod of the cutter blade drive mechanism and the ultrasonic converter are connected via a vibration transmission suppressing member. Thus, the vibration of the ultrasonic converter can be prevented from being transmitted to the cutter blade drive mechanism, and the operation of the cutter blade drive mechanism can be stabilized.

It is a block diagram which shows the parison cutting method and apparatus by this invention. It is process drawing which shows the state which cut | disconnects a parison by the parison cutting device of FIG. It is a wave form diagram which shows the cutter blade speed profile set to the calculator of FIG. It is a block diagram which shows the conventional parison cutting device. It is process drawing which shows the state which cut | disconnects a parison using the parison cutting device of FIG. It is process drawing which shows the other form of the conventional parison cutting method. It is process drawing which shows the well-known parison cutting method applicable to the parison cutting method and apparatus of this invention.

  The parison cutting method and apparatus according to the present invention reduces the frictional force between the cutter blade and the parison when cutting the parison by applying ultrasonic vibration to the cutter blade that cuts the parison, and eliminates friction due to the friction. And it is making the shape of the cut surface of a parison flat.

Hereinafter, preferred embodiments of a parison cutting method and apparatus according to the present invention will be described with reference to the drawings.
In addition, the same code | symbol is demonstrated to the part which is the same as that of a prior art example, or an equivalent part.
In FIG. 1, what is indicated by reference numeral 2 is a cutter blade for cutting the parison 3 discharged from the discharge port 1 a of the crosshead of FIG. 2, and one of the first support rods 10 of the cutter blade 2 is attached to the cutter blade 2. In the figure, a converter gripping portion 11, a vibration transmission suppressing member 12 made of an elastic material, and an ultrasonic converter 13 are stacked in a lateral direction and stacked.

  The other second support bar 14 of the cutter blade 2 is provided with a handle gripping portion 15, a vibration transmission suppressing member 16 made of an elastic material, and a cutter handle 17 stacked in a lateral direction and stacked from the inside.

A cable 19 of an ultrasonic oscillator 18 is connected to the outer end portion 10a of the first support rod 10 protruding from the ultrasonic converter 13, and the first rod 21 of the first cutter blade drive mechanism 20 is used to suppress vibration transmission. It is connected in the member 12.
A second rod 23 of a second cutter driving mechanism 22 is connected to the vibration transmission suppressing member 16, and ultrasonic vibration (30 kHz) is applied from the ultrasonic converter 13 to the cutter blade 2 via the first support rod 10. The ultrasonic vibration is absorbed by the vibration transmission suppressing members 12 and 16 so as not to be transmitted to the cutter driving mechanisms 20 and 21.
Therefore, the rods 21 and 23 of the cutter blade drive mechanisms 6 and 20 and the ultrasonic converter 13 are connected via the vibration transmission suppressing members 12 and 16.

  The first cutter blade drive mechanism 20 receives a speed command 31 from the calculator 30, and the second cutter blade drive mechanism 22 includes a sensor 32 such as an encoder, which is detected by the sensor 32. The position signal 33 is input to the cutter blade position detector 34, and the position information 35 indicating the position between the solid line and the dotted line of the cutter blade 2 output from the cutter blade position detector 34 is input to the computing unit 30 to receive each cutter. The cutter blade 2 is configured to reciprocate by the blade drive mechanisms 20 and 22.

In the calculator 30, as shown in FIG. 3, the cutting speed arrival position P1, the cutting end position P2, the internal cutting speed arrival position P3, the internal cutting end position P4, the cutting speed arrival position P5, and the cutting end position P6. The cutter cutting speed profile is created by inputting the cutting speed V1, the internal cutting speed V2, and the cutting speed V3.
That is, the cutting speed V3 of the cutter blade 2 from the cutting speed arrival position P1 to the cutting end position P2, and the internal cutting speed V2 of the cutter blade 2 from the cutting speed arrival position P5 to the cutting end position P6 Is set to be faster than the cutting speed V1 of the cutter blade 2 from the internal cutting speed arrival position P3 to the internal cutting end position P4.
Therefore, when the cutter blade 2 is cut into the parison 3 and cut out from the parison 3, the cutter blade 2 is made faster than the cutting speed of the cutter blade 2 between the cut and cut. The cut surface 3a of the parison 3 is configured to be flat.

In the parison cutting device 40 shown in FIG. 1 described above, the cutter blade drive mechanisms 20 and 22 are constructed by a servo motor or the like, and the cutter is operated by a speed command 31 based on the cutter cutting speed profile output from the computing unit 30. The cutting speed of the blade 2 is changed.
Especially when cutting into the parison 3 and when cutting out from the parison 3, the contact area between the cutting edge and the parison 3 is large, a large cutting force is required, and the slide speed of the cutter blade 2 is low. The parison 3 is pushed out by the cutter blade 2 without sufficient cutting force, and as a result, the shape of the lower end of the parison is not flat. Therefore, there is a relationship between the cutting force and the cutting speed, and the higher the cutting speed, the higher the cutting force. In the present invention, in particular, the P1-P2 section into the parison 3 and the P5-P6 section from the parison 3 are moved at high speeds V3 and V2, and the cutting force is increased by increasing the cutting speed, and the parison is pushed. It becomes possible to cut without stretching.
It should be noted that the acceleration and velocity V1 in the P2-P3 and P5-P6 sections are preferably changed depending on the thickness of the parison, and the optimum P1-P6 positions differ depending on the parison diameter, so that they can be arbitrarily changed on the program. . Further, position information 35 for determining the speed command 31 is obtained from a cutter blade position detector 34 including an encoder of a servo motor, a displacement sensor, and the like.

Incidentally, the parison 3 in FIG. 2 is not a regular cylindrical shape but a undulating cylindrical shape as shown in FIG. This is called a curtain phenomenon and occurs particularly in the case of the large-diameter parison 3.
At this time, since the ultrasonic vibration is applied to the cutter blade 2, the frictional force between the cutter blade 2 and the parison 3 can be reduced when the parison 3 is cut, and the conventional example shown in FIG. Thus, the parison 3 can be flattened as shown in FIG. 2C without the parison 3 being stretched as in the prior art by rubbing the cutter blade 2 and the parison 3.
That is, according to the present invention, ultrasonic vibration is applied to the cutter blade 2, and in particular, when cutting into the parison 3 and when cutting out from the parison 3, the cutter blade 2 is accelerated and cut to cut the parison 3. Can be cut without stretching.
Furthermore, the frictional force between the cutter blade 2 and the parison 3 can be reduced by ultrasonic vibration, the friction between the cutter blade 2 and the parison 3 due to friction can be eliminated, and the parison cutting surface 3a can be flattened. .

The gist of the above-described parison cutting method and apparatus according to the present invention is as follows.
That is, the parison 3 discharged from the crosshead 1 is pressed and cut with a variable-speed cutter blade 2 to which ultrasonic vibration is applied, and the cutter blade 2 is cut into the parison 3. And at the time of cutting from the parison 3, the cutting speed of the cutter blade 2 between the cutting time and the cutting time is faster than the cutting speed of the cutter blade 2, and the ultrasonic vibration is 30 kHz or more The cutter blade drive mechanisms 20 and 22 for driving the cutter blade 2 are driven by a speed command 31 from the calculator 30, and the calculator 30 is at the cut-off speed reaching position. P1, cutting end position P2, internal cutting speed arrival position P3, internal cutting end position P4, cutting speed arrival position P5, cutting end position P6, cutting speed V1, internal By setting the part cutting speed V2 and the cutting speed V3, a cutter blade speed profile is automatically created, and the cutter blade 2 is driven based on the created cutter blade speed profile. An ultrasonic converter 13 connected to an ultrasonic oscillator 18 is connected to one end of the cutter blade 2, and vibration is transmitted between the rods 21 and 23 of the cutter blade driving mechanisms 20 and 22 and the ultrasonic converter 13. The configuration and method are connected via the suppression members 12 and 16.

  The parison cutting method and apparatus according to the present invention can obtain a flat cut surface regardless of the diameter of the parison, can reduce the waste material of the parison during hollow molding, and can improve productivity.

DESCRIPTION OF SYMBOLS 1 Crosshead 1a Discharge port 2 Cutter blade 3 Parison 3a Cutting surface 10 1st support rod 10a Outer end 11 Converter gripping part 12 Vibration transmission suppression part 13 Ultrasonic converter 14 Second support bar 15 Handle gripping part 16 Vibration transmission suppression member DESCRIPTION OF SYMBOLS 17 Cutter handle 18 Ultrasonic oscillator 19 Cable 20 1st cutter blade drive mechanism 21 1st rod 22 2nd cutter blade drive mechanism 23 2nd rod 30 Calculator 31 Speed command 32 Sensor 33 Position signal 34 Cutter blade position detector 35 Position Information 40 Parison cutting device P1 Cutting speed arrival position P2 Cutting end position P3 Internal cutting speed arrival position P4 Internal cutting end position P5 Cutting speed arrival position P6 Cutting end position V1 Cutting speed V2 Internal cutting speed V3 Cutting speed

Claims (10)

  A parison cutting method characterized in that the parison (3) discharged from the crosshead (1) is cut by a variable-speed cutter blade (2) provided with ultrasonic vibration.   When the cutter blade (2) is cut into the parison (3) and cut out from the parison (3), the cutter blade (2) is cut between the cut and cut out. The parison cutting method according to claim 1, wherein the parison cutting speed is higher than the speed.   The parison cutting method according to claim 1 or 2, wherein the ultrasonic vibration is 30 kHz or more.   The cutter blade drive mechanism (20, 22) for driving the cutter blade (2) is driven by the speed command (31) from the computing unit (30), and the computing unit (30) is the cutting speed reaching position. (P1), cutting end position (P2), internal cutting speed arrival position (P3), internal cutting end position (P4), cutting speed arrival position (P5), cutting end position (P6), cutting speed (V1) By setting the internal cutting speed (V2) and cutting speed (V3), a cutter blade speed profile is automatically created, and the cutter blade (2) is driven based on the created cutter blade speed profile The parison cutting method according to any one of claims 1 to 3.   An ultrasonic converter (13) connected to an ultrasonic oscillator (18) is connected to one end of the cutter blade (2), and the rod (21, 23) of the cutter blade drive mechanism (20, 22) and the ultrasonic blade (2). The parison cutting method according to claim 4, wherein the sound wave converter (13) is connected via a vibration transmission suppressing member (12, 16).   A parison cutting device characterized in that the parison (3) discharged from the crosshead (1) is pressed by a variable-speed cutter blade (2) provided with ultrasonic vibration.   When the cutter blade (2) is cut into the parison (3) and cut out from the parison (3), the cutter blade (2) is cut between the cut and cut out. The parison cutting device according to claim 6, wherein the parison cutting device is faster than the speed.   The parison cutting device according to claim 6 or 7, wherein the ultrasonic vibration is 30 kHz or more.   The cutter blade drive mechanism (20, 22) for driving the cutter blade (2) is driven by the speed command (31) from the computing unit (30), and the computing unit (30) is the cutting speed reaching position. (P1), cutting end position (P2), internal cutting speed arrival position (P3), internal cutting end position (P4), cutting speed arrival position (P5), cutting end position (P6), cutting speed (V1) By setting the internal cutting speed (V2) and cutting speed (V3), a cutter blade speed profile is automatically created, and the cutter blade (2) is driven based on the created cutter blade speed profile The parison cutting device according to any one of claims 6 to 8.   An ultrasonic converter (13) connected to an ultrasonic oscillator (18) is connected to one end of the cutter blade (2), and the rod (21, 23) of the cutter blade drive mechanism (20, 22) and the ultrasonic blade (2). The parison cutting device according to claim 9, wherein the parison cutting device is connected to the acoustic wave converter (13) via a vibration transmission suppressing member (12, 16).

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