JP2006315325A - Electric motor-driven nozzle fitting apparatus and method for hollow-molding using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a quality hollow molding product by fitting an air nozzle using a servo motor having an encoder so as to precisely control a fitting position of the air nozzle in two steps. <P>SOLUTION: The electric motor-driven nozzle fitting apparatus comprises: a servo motor having an encoder and provided on a main body; a ball screw provided protrusively on a main body and rotatably driven by the servo motor; a sleeve member having a nut member screwed together with the ball screw; an air nozzle provided on the tip of the sleeve member; a plurality of rods provided on the sleeve member and positioned at the outside of the main body; and guide holes provided on the lateral side of the main body for slidably guiding the rods, wherein the position of the air nozzle is controlled by rotational control of the servo motor. A protruded part is formed on the main body so that the guide holes are formed at the protruded part. The main body has a plurality of proximity switches on its lateral side provided at different positions along the longitudinal direction of the main body wherein the position of the air nozzle is detected by detecting the position of the rods. A stopper having a concave portion and a tongue piece is provided at the tip of the rod wherein the proximity switch is positioned in the concave portion and responds to the tongue piece when the stopper moves together with the rod. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric driving device and a hollow molding method using the same, and in particular, performs a driving operation of an air nozzle using a servo motor having an encoder, and controls the driving position of the air nozzle in two stages with high accuracy. The present invention relates to a novel improvement for obtaining a quality hollow molded article.

Conventionally, this type of driving device and a hollow molding method using the same have not been cited, but the configurations shown in FIGS. 8 and 9 can be exemplified.
In the case of the conventional configuration of FIG. 8, the hydraulic nozzle 1 is configured to raise / lower the air nozzle 2, and a hydraulic pressure source 3 is connected to the hydraulic cylinder 1.

  Further, in the case of the conventional configuration shown in FIG. 9, the position when the air nozzle 2 is raised / lowered is detected by the position detecting means 5 using the limit switch 4, and the air nozzle 2 is moved against the parison in the mold (not shown). When driving, the air nozzle is temporarily stopped, and then the air nozzle is driven once again to control the position of the air nozzle 2 in two stages.

Since the conventional driving device and the hollow molding method using the same have the following configurations, the following problems existed.
First, in the conventional configuration of FIG. 8, since there is no position detection mechanism for the air nozzle, when the air nozzle is raised, the air nozzle is driven into the parison at once to the hydraulic cylinder end (ie, the stroke end), and the mouth of the hollow molded product It was difficult to improve the molding quality.

In the case of the conventional configuration shown in FIG. 9, it is possible to temporarily stop the air nozzle in the middle, and then raise the air nozzle once and drive it in again. However, since the mechanical limit switch is used, the oil temperature rises. Alternatively, due to the dead zone of the limit switch, it is difficult to obtain the repeatability of the position at which it stops in the middle, and it is difficult to obtain a stable quality of the molded product.
In particular, in order to obtain the accuracy of the end face of the cap mouth of a container or the like, the air nozzle is temporarily stopped at a position 3 mm to 5 mm before the die mouth, and then the air nozzle is raised again and pressed against the die mouth. Although it is necessary, it is difficult to position the air nozzle as described above, and it is difficult to improve the quality of the molded product.

  An electric driving device according to the present invention includes a servo motor having an encoder provided in a main body, a ball screw protruding from the main body and driven to rotate by the servo motor, and a sleeve body having a nut body screwed with the ball screw. An air nozzle provided at the distal end of the sleeve body, a plurality of rods provided on the sleeve body and positioned outside the main body, and a guide provided on the side portion of the main body to freely move the rod. A guide hole, and the position of the air nozzle is controlled by the rotation control of the servo motor. The main body has a protrusion, and the guide hole is formed in the protrusion. And a plurality of proximity switches provided at different positions along the longitudinal direction of the main body on the side of the main body. The position of the air nozzle is detected by detecting the position of the rod with the proximity switch, and a stopper having a recess and a tongue piece is provided at the tip of the rod. A hollow molding method using the electric driving device according to the present invention is configured such that, when moving together with the rod, the proximity switch is positioned in the recess and corresponds to the tongue piece. In the hollow molding method in which the air nozzle is driven into a parison in a mold using the electric driving device according to any one of 1 to 4 and blow air is blown into the parison, The air nozzle is driven into the mold as the first stage position, and after the parison is pushed into the mold and the mold is closed, the air nozzle Driving the second stage position of the rear side of the first stage position, the first stage position and second stage position is a method for controlling the servo motor by using the rotation detection signal from the encoder.

Since the electric driving device and the hollow molding method using the same according to the present invention are configured as described above, the following effects can be obtained.
That is, the ball screw is rotated by numerical control with a servo motor having an encoder, and the air nozzle provided on the nut body via the sleeve can be controlled in two stages with extremely high accuracy by the servo motor.
Accordingly, it is possible to improve the repeatability of raising and lowering the air nozzle.
Further, since a servo motor having an encoder is used, it is no longer necessary to add a position detection sensor such as a limit switch as in the prior art.
In addition, since the air nozzle is controlled to move up and down by an encoder and servo motor, there is almost no deviation between the set value and the actual measurement value when the air nozzle is moved up, and a highly accurate cap ( Mouth) end face can be obtained.

  The present invention relates to an electric driving device that performs a driving operation of an air nozzle using a servo motor having an encoder, controls the driving position of the air nozzle in two stages with high accuracy, and obtains a high-quality hollow molded product, and the same It aims at providing the hollow molding method using this.

Hereinafter, preferred embodiments of an electric driving device and a hollow molding method using the same according to the present invention will be described with reference to the drawings.
In addition, the same code | symbol is attached | subjected and demonstrated to a part the same as that of a prior art example, or an equivalent part.
FIG. 1 shows an outline of an electric driving apparatus 20 according to the present invention. In FIG. 1, reference numeral 10 denotes an encoder for position detection. This encoder 10 constitutes a motor encoder provided in a servo motor 11. is doing.
The ball screw 12 connected to the servo motor 11 via a coupling 11 a is provided with a nut body 17, and the air nozzle 2 is attached to the nut body 17.

  2 to 4 specifically show the electric driving device 20 of FIG. 1 described above. The servo motor 11 is provided in a hollow main body 14, and the ball screw 12 is connected to the bearing 15 in the main body 14. It is provided rotatably through the.

  The ball screw 12 is screwed with a nut body 17 provided with a sleeve body 16 with one end closed, and a bellows 18 is provided between the lower end of the nut body 17 and the upper end of the main body 14. The ball screw 12 is covered with a bellows 18.

  The ball screw 12 is positioned in the sleeve body 16 and is configured such that the sleeve body 16 and the nut body 17 are moved up and down along the direction of arrow A by rotating the ball screw 12 by the servo motor 11. Has been.

A plurality of rods 19 are provided outside the sleeve body 16 at the lower end portion 16a of the sleeve body 16, and the rods 19 are arranged in parallel with the axial direction of the ball screw 12, as shown in the figure. It is installed.
Each rod 19 is operably penetrated through a guide hole 31 of a protrusion 30 formed at the upper end of the main body 14.
The rods 19 are operatively inserted into the guide holes 31 to prevent the nut body 17 and the sleeve body 16 from rotating when the ball screw 12 rotates, and the sleeve body 16 and the air nozzle 2 can be moved up and down. It is configured.

FIG. 4 shows a state in which the sleeve body 16 and the air nozzle 2 are raised upward in the cross-sectional view of the electric driving device 20 shown in FIG.
Further, the tip portion 19a of the rod 19 is not contacted to the side portion of the main body 14 with the three first, second, and third proximity switches 40, 41, 42 shifted in the longitudinal direction. The first proximity switch 40 detects the upper limit of driving of the air nozzle 2, the second proximity switch 41 detects the origin of the air nozzle 2, and the third proximity switch 42 drives the air nozzle 2. The lower limit can be detected. That is, the tip 19a is provided with a stopper 100 made of a horizontally long metal via a pair of rods 19 as shown in FIG. 3, and a recess 19A and a tongue piece 19B are formed on the side of the stopper 100. The proximity switches 40 to 42 can be positioned correspondingly in the recess 19 </ b> A, and can be detected at the positions described above by raising and lowering the air nozzle 2. The detection signal of the second proximity switch 41 is used to calibrate the mechanical position and the electrical position (motor encoder position) when the power is turned on.

Next, a case where hollow molding is performed using the electric driving device 20 in the above-described configuration will be described.
First, a description will be given of the case of lower punching molding in which the air nozzle 2 shown in FIG. 5 is driven from below the parison 51 extruded from the die 50 of the crosshead 50A.
As shown in FIG. 5A, the parison is pushed toward the air nozzle 2 located below the die 50 (the position of the air nozzle at this time is detected by the third proximity switch 42). ), The mold 52 comes to the preliminary mold closed position, and the servo motor 11 of the electric driving device 20 rotates while being controlled via the motor drive unit by a preset motor command, so that the first stage position P1 is reached. Nozzle driving is performed, and this first stage position P1 is obtained based on the calculation result of the encoder output signal from the encoder 10.

  Next, in (C), the mold 52 is closed (holding pressure), and the air nozzle 2 remains at the first stage position.

Next, in (D), due to the additional rotation of the servo motor 11, the air nozzle 2 is driven further into the back of the parison 51 from the first stage position P1, and the second stage position P2 (the first proximity switch 40). And the pre-blow into the parison 51 and the main blow are started, and hollow molding is performed.
FIG. 6 separately shows the pre-blow and main-blow states of the bottom punching molding of FIG. Note that the position of the air nozzle 2 is controlled extremely accurately by the feed control by the servo motor 11, so that a conventional switch is not necessary, but detection by the proximity switches 40 to 41 is used for position confirmation. It has been. The proximity switches 40 to 41 can be magnetic, optical, or the like.

Next, FIG. 7 shows a process of upper punch molding opposite to the aforementioned lower punch molding.
That is, in FIG. 7, the parison 51 extruded from the die 50 as shown in FIG. 7A is cut by the cutter blade 60, the mold 52 is opened in FIG. 7B, and the air nozzle 2 is moved above the parison 51 in FIG. More.

Thereafter, when the mold 52 is closed (holding pressure), air is blown into the parison 51 from the air nozzle 2 to perform hollow molding to obtain a hollow molded product.
In the above-described driving of the air nozzle 2, the position control of the first-stage position P1 and the second-stage position P2 of the air nozzle 2 shown in FIGS. 5 and 6 is performed, but is omitted here.

  The present invention can be applied not only to raising and lowering an air nozzle of a hollow molding machine but also to, for example, a highly accurate linear actuator.

It is a block diagram which shows the outline | summary of the electrically driven driving device by this invention. It is front sectional drawing which shows the apparatus of FIG. 1 concretely. It is CC sectional drawing of FIG. FIG. 3 is a left side view of FIG. 2. FIG. 6 is a process diagram of lower die forming when hollow molding is performed using the electric driving device of the present invention. FIG. 6 is a process diagram specifically showing a part of the process of FIG. 5. It is a process drawing of the top punching molding which shows the hollow molding of this invention. It is a block diagram which shows the conventional driving device. It is a block diagram which shows the other conventional driving device.

Explanation of symbols

2 Air nozzle 10 Encoder 11 Servo motor 14 Main body 16 Sleeve body 17 Nut body 18 Bellows 19 Rod 20 Electric driving device 40 First proximity switch 41 Second proximity switch 42 Third proximity switch 50 Die 51 Parison 52 Mold 60 Cutter blade

Claims (5)

A servo motor (11) provided with an encoder (10) provided in the main body (14), a ball screw (12) protruding from the main body (14) and driven to rotate by the servo motor (11), and the ball screw ( 12) a sleeve body (16) having a nut body (17) screwed together, an air nozzle (2) provided at the tip of the sleeve body (16), and the main body (16) provided in the sleeve body (16). 14) provided with a plurality of rods (19) located on the outside of the main body (14) and a guide hole (31) for guiding the rod (19) so as to move freely.
An electric driving device characterized in that the position of the air nozzle (2) is controlled by rotation control of the servo motor (11).   The electric driving device according to claim 1, wherein a protrusion (30) is formed in the main body (14), and the guide hole (31) is formed in the protrusion (30).   The side of the main body (14) has a plurality of proximity switches (40, 41, 42) provided at different positions along the longitudinal direction of the main body (14), and the position of the rod (19) The electric driving device according to claim 1 or 2, wherein the position of the air nozzle (2) is detected by detecting the position by the proximity switch (40, 41, 42).   The tip (19a) of the rod (19) is provided with a stopper (100) having a recess (19A) and a tongue piece (19B), and when the stopper (100) moves together with the rod (19), The proximity switch (40, 41, 42) is located in the recess (19A) and is configured to correspond to the tongue piece (19B). Electric driving device. The electric nozzle (2) is driven into a parison (51) in a mold (52) using the electric driving device (20) according to any one of claims 1 to 4, and blow air is blown into the parison (51). In the hollow molding method to blow,
The air nozzle (2) is driven into the mold (52) being opened as a first stage position (P1), and the parison (51) is extruded into the mold (52), so that the mold (52) After the mold is closed, the air nozzle (2) is driven into the second stage position (P2) at the back of the first stage position (P1), and the first stage position (P1) and the second stage position A hollow molding method using an electric driving device, wherein the position (P2) controls the servo motor (11) using a rotation detection signal from the encoder (10).

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