JPH1024485A - Blow molding method and blow molder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a double station type mold movement and blowing nozzle action by a method wherein respective molds are alternately moved through mold transferring clutches by the driving force of a common motor for mold transferring. SOLUTION: Under the condition that a first mold 10 already pinches a parison 21a sent from a crosshead 20 and a first blowing nozzle 14 is going to lower through a first blowing clutch 58 by means of the rotation of a blowing common motor 12, a second mold 11 locates just below the crosshead 20 and starts to receive the supply of the next parison 20a. Concretely, by the driving force of a common motor 2 for mold transferring, the first mold 10 is moved through a common gear box 2A for mold transferring and a first clutch 34 for mold transferring so as to correspond to the first blowing nozzle 14. After that, by turning OFF the first clutch 34 for mold transferring and ON a second clutch 35 for mold transferring, the second mold 11 is located just below the crosshead 20 so as to supply the parison 20a from the crosshead 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow molding method and a hollow molding machine, and more particularly to a double-station type mold moving and blowing nozzle operation by a single mold transferring common motor and a single blowing common motor. Related to new improvements.

[0002]

2. Description of the Related Art Conventionally, as a blow molding machine of this type, a hydraulically driven double station type configuration as shown in FIG. 4 has been adopted in order to perform highly efficient production. That is, what is indicated by reference numeral 1 in FIG. 4 is a base, and first and second ball screws driven by first and second mold transfer hydraulic cylinders 2 and 3 are provided on the base 1. First and second mold clamping mechanisms 8 and 9 having first and second mold clamping hydraulic cylinders (not shown) are movably provided on the ball screws 4 and 5, respectively. First and second molds 10 and 11 are provided in the tightening mechanisms 8 and 9. At the blowing position where each of the molds 10 and 11 stops,
Blow nozzles 14 and 15 having first and second hydraulic cylinders 12 and 13 for blow are provided to be vertically movable. The crosshead 20 of the extruder is located between each blow nozzle.

Next, the operation will be described. As shown in FIG. 4, the first mold transfer hydraulic cylinder 2 is operated to make the first mold 10 correspond to the crosshead 20, and in this state, the parison (not shown) from the crosshead 20 is moved to the first mold. It is clamped within 10. Thereafter, the first mold 10 is positioned below the first blowing nozzle 14, and the first blowing nozzle 14 is lowered to blow air to perform hollow molding. At the same time, the hydraulic cylinder 3 for transferring the second mold is operated to make the second mold 11 correspond to the crosshead 20, and in this state, the parison from the crosshead 20 is clamped in the second mold 11. afterwards,
Position the second mold 11 below the second blowing nozzle 15 and
The blow nozzle 15 is lowered to blow air to perform blow molding. As described above, the double-station type hollow molding is performed by reciprocating the molds 10 and 11 alternately between the crosshead and the blowing nozzles 14 and 15.

[0004]

The conventional hydraulic double-station type blow molding machine has the following problems because it is constructed as described above. That is,
Since a pair of hydraulic cylinders are required for each of the mold transfer, mold clamping and blowing, the mechanism becomes complicated and cost reduction is difficult. In addition, since the flow rate of the oil flowing into the hydraulic cylinder changes according to the change in the oil temperature during molding, that is, the change in the viscosity of the oil, the moving speed of the mold changes accordingly, and the air blowing of the mold There has been a problem that the timing of the return to the position and the start of the operation of the air blowing device may be out of order, resulting in defective molding. Also, when the oil temperature becomes abnormally high and the viscosity of the oil becomes lower than necessary, the flow velocity of the oil flowing into the hydraulic cylinder increases,
Since the piston of the hydraulic cylinder moves at a high speed, the device receives a large impact at the stop position, and the parison swings, and the relation position with the mold located at the parison receiving position becomes inconsistent, so that pinching failure easily occurs. For,
Molding defects were likely to occur. In order to prevent such problems, it is necessary to maintain the temperature of the oil supplied to the hydraulic cylinder within a predetermined temperature range. There is a problem that the cost of the product increases because an oil temperature adjusting device is required for stabilization. Furthermore, the piping of the hydraulic system is complicated, oil leaks easily occur, and the molded product is stained, which is a serious problem at the time of hollow molding.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in particular, a double station type mold moving and blowing nozzle operation is performed by a single mold transferring common motor and a blowing common motor. It is an object of the present invention to provide a hollow molding method and a hollow molding machine which are performed.

[0006]

According to the present invention, there is provided a hollow molding method wherein a parison hung from a crosshead is alternately sandwiched between a pair of dies which reciprocate with each other, and is fixedly provided above each of the dies. In a hollow molding method in which a pair of blow nozzles are alternately operated to perform hollow molding,
In this method, the molds are alternately moved via a mold transfer clutch by a driving force of a mold transfer common motor.

More specifically, there is a method in which the vertical movement of each of the blowing nozzles is alternately performed via a blowing clutch by the driving force of a common motor for blowing.

In a blow molding machine according to the present invention, a pair of parisons hanging down from a crosshead are alternately sandwiched between a pair of dies that reciprocate with each other, and a pair of blows fixedly provided above each of the dies. In a blow molding machine in which the nozzles are alternately operated to perform blow molding, a mold transfer common motor for alternately moving the respective molds via a pair of mold transfer clutches, A configuration is provided with a common blow motor for alternately moving each blow nozzle through a pair of blow clutches.

More specifically, each of the dies is connected to a pair of die transfer devices connected to a pair of ball screws provided on a base, and each of the ball screws is connected to each of the die transfer devices. And a common gear box for transferring the mold is connected to the common gear box for transferring the mold via a clutch for use.

[0010] More specifically, each of the blowing nozzles is provided on a mounting table connected to a frame on the base,
Each of the blowing nozzles has a ball screw, a thrust bearing,
A coupling and an individual gear box, wherein each of the individual gear boxes is connected to a common blowing gear box via a pair of blowing clutches, and the common blowing motor is connected to the common blowing gear box. Configuration.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a blow molding method and a blow molding machine according to the present invention will be described below with reference to the drawings. The same or equivalent parts as those in the conventional example will be described with the same reference numerals. In FIG. 1, what is indicated by reference numeral 1 is a base, on which a pair of blocks 3
0, 31 and the first through a pair of brackets 32, 33
A ball screw 4 and a second ball screw 5 are rotatably provided. The ball screws 4 and 5 are connected to a common mold transfer common to the ball screws 4 and 5 via first and second mold transfer clutches 34 and 35 and first and second couplings 36 and 37, respectively. It is connected to the gear box 2A. The common motor 2 for transferring the mold is connected to the common gear box 2A for transferring the mold via a coupling 38, and the nuts 40 and 41 screwed to the ball screws 4 and 5 have the first First and second mold transfer devices 42 and 43 having well-known first and second mold clamping devices 8 and 9 having second molds 10 and 11 are connected. Accordingly, the rotation of the motor 2 rotates the ball screws 4 and 5 via the clutches 34 and 35, thereby moving the mold transfer devices 42 and 43.

A mounting base 45A provided so as to extend over a pair of frames 44 and 45 provided on the base 1.
, Well-known first and second blowing nozzles 14 and 15 are provided so as to be vertically movable, and each of the blowing nozzles 14 and 15 is provided with ball screws 46 and 47, thrust bearings 48 and 49, couplings 50 and 51, and individual It is connected to gear boxes 52 and 53. Each of the individual gear boxes 52, 53
The coupling 54, 55, 56, 57 and the first and second blowing clutches 58, 59 are commonly connected to a blowing common gear box 60 located at the center of the mounting base 45A. The common motor 12 for blowing is connected to the gear box 60. Therefore, this motor 1
The rotation of 2 causes the nozzles 14 and 15 to move up and down via the ball screws 46 and 47 and the clutches 58 and 59. The mold clamping devices 8 and 9 for opening and closing the molds 10 and 11 are well known (for example, see JP-A-5-3380).
No. 19, disclosed in Utility Model Registration No. 3001598)
Therefore, the disclosure of the structure is omitted here. The common motor 2 for transferring the mold, the clutches 34,
The operation of a known extruder (not shown) connected to each of the mold clamping devices 8 and 9, each of the blow nozzles 14 and 15, each of the clutches 58 and 59, the common blow motor 12, and the crosshead 20 is not shown. It is performed by

Next, the operation will be described. First, as shown in the state of FIG.
Of the parison 20a from the
Is rotating and the first blowing nozzle 14 is descending via the first blowing clutch 58, the second mold 11 is located immediately below the crosshead 20 and starts receiving the next parison 20a. . That is, in the state shown in FIG. 1, the first mold 10 is driven by the driving force of the common motor 2 for transferring the mold to the first gear box 2A via the common gearbox 2A for transferring the mold and the clutch 34 for transferring the first mold. 14, the first mold transfer clutch 34 is turned off, and the second mold transfer clutch 35 is turned on, so that the second mold transfer clutch 35 is turned on.
The mold 11 is positioned directly below the crosshead 20, and the parison 20 a is supplied from the crosshead 20.

In the state described above, the rotation of the common motor 12 for blowing is turned on only the first clutch 58 for blowing, so that only the first ball screw 48 is rotated and the first blowing nozzle 14 descends. The first blowing nozzle 14 is connected to the first mold 10
It is driven into the parison inside and the hollow molding is performed. After the completion of the hollow molding in the first mold 10, the mold is opened as is well known, and a molded product (not shown) is taken out. Thereafter, the first and second mold transfer clutches 34, 35
Is turned on, the respective molds 10 and 11 move rightward, the first mold 10 is located directly below the crosshead 20, the second mold 11 is located immediately below the second blowing nozzle 15, The two-blowing crosshead 59 is turned on, and the parison in the second mold 11 is driven by the second blowing nozzle 15. FIG. 3 shows the operations in the respective molding cycles of going and returning the dies 10, 11 and raising and lowering the blowing nozzles 14, 15 by the sequence driving of the clutches 34, 35, 58, 59 described above. According to this operation, each of the clutches 34, 35,
The on / off operations of 58 and 59 are performed. Further, the above-described mold clamping devices 8 and 9 are provided with the respective molds 10 and
This operation is performed to open and close the mold and clamp the mold, and thus is omitted here.

[0015]

The blow molding method and the blow molding machine according to the present invention are configured as described above, so that the following effects can be obtained. That is, the row and return of each mold transfer device and the lowering and rising of each blow nozzle can be achieved by only one common motor for transferring the mold and the common motor for blowing by using the respective clutches. In addition, it is possible to obtain a device in which the number of motors to be used is halved, the weight is reduced, and the cost is reduced. In addition, since the mold is operated by the servo motor, the mold can be stopped so as not to give an impact to the device, and the time required for the movement of the mold can be kept constant. It is possible to prevent the occurrence of a defective molded product due to a sandwiching failure due to the above, and an air blowing failure due to an irregular molding timing. In addition, since the moving speed of the mold corresponding to the number of revolutions of the servomotor can be displayed, the reproducibility of the molding timing can be achieved based on this, and the molding quality can be improved. In connection with this, at the time of setup change, the adjustment time for non-defective product production can be shortened. A clean molding environment free of hydraulic oil contamination can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a blow molding machine according to the present invention.

FIG. 2 is a plan view showing a main part of FIG.

FIG. 3 is a sequence diagram showing the operation of FIG.

FIG. 4 is a configuration diagram showing a conventional hydraulic blow molding machine.

[Explanation of symbols]

 Reference Signs List 1 base 2 mold transfer common motor 10,11 mold 12 blow common motor 14,15 blow nozzle 2A mold transfer common gear box 34,35 mold transfer clutch 42,43 mold transfer device 44,45 Frame 45A Mounting base 46, 47 Ball screw 48, 49 Thrust bearing 50, 51 Coupling 52, 53 Individual gear box 58, 59 Blowing clutch 60 Blowing common gear box

Claims (5)

[Claims] 1. A parison hanging from a crosshead (20)
(20a) are alternately sandwiched between a pair of dies (10, 11) reciprocating with each other, and a pair of blowing nozzles (14, 14) fixedly provided above the dies (10, 11) are provided. In the hollow molding method in which the hollow molding is performed by alternately operating the molds (15), the mold transfer clutches (34, 3) are driven by the driving force of the mold transfer common motor (2).
A hollow molding method, wherein the molds (10, 11) are alternately moved via 5). 2. The vertical movement of each of the blowing nozzles (14, 15)
The driving force of the common blow motor (12)
8. The method according to claim 1, wherein the steps are carried out alternately through the steps (8, 59). 3. A parison hanging from the crosshead (20).
(20a) are alternately sandwiched between a pair of dies (10, 11) reciprocating with each other, and a pair of blowing nozzles (14, 14) fixedly provided above the dies (10, 11) are provided. In the hollow molding machine in which the hollow molding is performed by alternately operating the molds (15), the respective dies (1
(0,11) via a pair of mold transfer clutches (34,35) alternately, and a pair of mold transfer common motors (2), and each of the blowing nozzles (14,15). Blow common motor (12) for alternately moving through the blow clutch (58, 59)
And a hollow molding machine comprising: 4. Each of the dies (10, 11) is provided with a pair of mold transfer devices (42, 43) connected to a pair of ball screws (4, 5) provided on a base (1). ), And each of the ball screws (4, 5) is connected to a common mold transfer gear box (2A) via each of the mold transfer clutches (34, 35), and is connected to the common mold transfer The blow molding machine according to claim 3, wherein the common motor (2) for transferring the mold is connected to a gear box (2A). 5. Each of the blowing nozzles (14, 15) is mounted on the base.
(1) Provided on a mounting base (45A) connected to the upper frame (44, 45), and each of the blowing nozzles (14, 15) is a ball screw (46, 4).
7), thrust bearing (48,49), coupling (50,51)
And individual gear boxes (52, 53), each of the individual gear boxes (52, 53) is connected to a common blow gear box (60) via a pair of blow clutches (58, 59), The blow molding machine according to claim 3 or 4, wherein the blow common motor (12) is connected to the blow common gear box (60).