JPH08103947A - Method and apparatus for clamping mold of hollow molding machine - Google Patents

Abstract

PURPOSE: To shorten the operating time by eliminating the necessity of mold thickness regulating operation and to obviate a stepwise difference at the pinch- off part of the bonded part of both mold parts of a mold and a parison in the toggle mechanism of a hollow molding machine. CONSTITUTION: Respective one ends of first and second toggle pieces 7, 8 are connected to a second mold holder 10 and a rear plate 18, and the other ends of the pieces 7, 9 are respectively rotatably and slidably connected to guide blocks 12 via support shafts. Roller bearings are provided at the shafts, and wedges 35a which can be inserted between both the bearings arranged at the other ends of the pieces 7, 8 is provided at the blocks 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for clamping a hollow molding machine, and more particularly to a method and an apparatus for clamping an electric hollow molding machine which opens and closes a mold via a toggle mechanism driven by an electric motor.

[0002]

2. Description of the Related Art The applicant of the present invention has previously proposed a mold clamping device for a hollow molding machine having the following structure and action in Japanese Patent Laid-Open No. 6-867. That is, FIG. 4 is a front view of a mold clamping device of a conventional hollow molding machine, and FIG. 5 is a plan view thereof. In FIG. 4 and FIG. 5, what is indicated by reference numeral 1 is an openable and closable mold composed of a first mold part 2 and a second mold part 3, and the cavity 1 a of the mold 1 is extruded. The parison 6 depending from the crosshead 5 of the machine 4 is supplied.

The second mold part 3 is connected to a toggle mechanism 9 consisting of a pair of bendable first and second toggle pieces 7 and 8 via a second mold holder 10 and a first clevis 7a. The guide block 12 that holds the shaft support 11 to which the toggle pieces 7 and 8 are flexibly connected is configured to be guided by a pair of center positioning guide bars 13 and 14. The guide block 12 is configured to be axially reciprocable by a feed screw body 16 such as a ball screw rotated by an electric motor 15. The first mold part 2 of the mold 1 is attached to the first mold holder 17. A pair of rods 19 and 20 are connected to a rear plate 18 connected to the second toggle piece 8 via a second clevis 8a, and each rod 19, 20 is connected to the first mold holder 17. The rod 19 is fixedly connected to the connecting body 21, and the rod 19 penetrates the first mold holding body 10 so as to be movable, and the rear plate 18, the rods 19, 20 and the connecting body 21 form the mold. A mold opening / closing interlocking mechanism 50 for 1 is configured.

Therefore, by operating the electric motor 15 and the guide block 12 by the feed screw body 16 in the above-described structure, the toggle pieces 7 and 8 are moved to the positions shown by the solid line and the chain double-dashed line as shown in FIG. A linear shape or a curved shape is formed along the line, and in the case of a linear shape, the mold holders 10 and 17 move in the joining direction via the mold opening / closing interlocking mechanism 50. Is closed, and in the case of a refracting shape, the mold parts 2 and 3 are opened in the reverse order to the above.

In the mold clamping device of the blow molding machine described above, when the mold 1 is replaced, the mold clamping force of the mold 1 changes greatly due to a slight difference in the mold thickness dimension. In order to avoid this, every time the mold 1 is replaced, a spacer is inserted between the second mold holding body 10 and the first clevis 7a and between the second clevis 8a and the rear plate 18, and the applicant of the present invention specially Kaihei 5-329
The mold thickness is adjusted by inserting a movable member having a movable tapered surface and a fixed member having a fixed tapered surface, which are disclosed in Japanese Patent Publication No. 921, to each other.

[0006]

Since the mold clamping device of the conventional hollow molding machine described above is configured as described above, the following problems exist. That is, since the mold thickness adjustment is manually performed, it takes a long working time, and it is often the case that an appropriate tightening force cannot be obtained due to a poor adjustment.

Further, the second mold part constituting the mold is arranged such that the second mold holding body is interposed between the first toggle piece of the single toggle mechanism composed of the pair of bendable first and second toggle pieces. Since the mold is clamped by the toggle mechanism, the mold clamping force is dispersed in directions other than the mold clamping direction, and the second mold part is displaced from the first mold part, and both molds are connected. There has been a problem that a slight step is formed on the joint surface of the mold part and the cut-off part of the parison, and the quality of the molded product is impaired.

Further, as a feature of the toggle mechanism, the mold speed immediately before the mold clamping becomes slow, so that the cut-off state of the parison of the specific resin may become unstable. That is, engineering plastics such as polyethylene terephthalate (PET) and polycarbonate (PC)
Since they have a high melting point, when these molten resins come into contact with the mold surface, they are rapidly cooled and become very hard. Therefore, it is required to clamp the molten resin at a high speed immediately after the burr portion of the molten resin touches the blade of the mold to eat the burr, but the conventional toggle mechanism cannot cope with this. It was

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to eliminate a mold thickness adjusting operation in a mold clamping device of a hollow molding machine. It is to reduce the work time. Another purpose is to easily obtain an appropriate mold clamping force. Another object is to prevent a step from being formed in the joint surface of both mold parts and the cut-out part of the parison when the mold is clamped via the toggle mechanism. Still another object is to obtain a high mold clamping speed.

[0010]

According to the method of clamping a hollow molding machine of the present invention, a guide block (1) in which first and second toggle pieces (7, 8) are rotatably and slidably connected, respectively.
2) is moved forward so that the first and second toggle pieces (7, 8) are aligned, and then the guide block (1
Insert a wedge (35a) between both ends of the first and second toggle pieces (7, 8) whose ends are connected to 2),
This is a method of performing mold clamping by moving the first and second toggle pieces (7, 8).

The mold clamping device of the blow molding machine of the present invention comprises a guide block reciprocating in a direction perpendicular to the mold opening and closing direction, a toggle mechanism connected to the guide block, and a first block.
A first mold holding body holding a mold part, a second mold holding body connected to one end of the toggle mechanism and holding a second mold part, and a rear plate connected to the other end of the toggle mechanism. And one end is connected to the rear plate and the other end is the first
In a mold clamping device of a hollow molding machine, which comprises a pair of rods connected to a mold holder, the toggle mechanism includes a pair of bendable first and second toggle pieces, and one end of the first toggle piece is , The second die holder, one end of the second toggle piece is connected to the rear plate, and the other ends of the first and second toggle pieces are respectively connected to the guide block via a support shaft. Rotationally and slidably connected, a rotating body is fitted to each of the support shafts, and the rotation of the guide block is arranged at the other ends of the first and second toggle pieces of the toggle mechanism. A wedge portion having a wedge that can be inserted between the bodies is provided.

More specifically, guide pieces are provided above and below the support shaft, and the guide pieces are slidable in a direction perpendicular to the moving direction of the guide block by a guide portion provided on the guide block. You will be guided to.

More specifically, the guide block and the wedge of the wedge portion are adapted to be driven by respective electric motors through respective feed screw bodies.

[0014]

Operation: The guide block to which the toggle mechanism is connected is moved forward so that the first and second toggle pieces are aligned, and then the first and second end parts are connected to the guide block.
Inserting a wedge between both ends of the second toggle piece
The second toggle piece moves in the mold clamping direction along the guide part, the dimension between both mold parts becomes 0, and further, when the electric motor is rotated, the torque increases, and the force due to this torque is the first and the second. Two
It is transmitted to the mold part via the toggle piece, and an appropriate mold clamping force is obtained between both molds.

[0015]

EXAMPLES Examples will be described with reference to the drawings. Note that the same or equivalent portions as those of the conventional example will be described by giving the same reference numerals.

1 to 3 show a mold clamping device of a hollow molding machine according to the present invention, FIG. 1 is an operation view seen from a plane, and FIG. 2 is a front view of FIG. In addition, FIG.
It is a lII-IlI line stairs sectional view. In FIGS. 1 and 2, reference numeral 1 denotes an openable / closable mold including a first mold portion 2 and a second mold portion 3, and a reference numeral 9 denotes a pair of bendable first and second toggle pieces 7, 8 shows a toggle mechanism consisting of 8.

One end of the first toggle piece 7 of the toggle mechanism 9 is connected to the second mold part 3 via the first clevis 7a and the second mold holder 10, and the second mold part 3 is also connected.
One end of the toggle piece 8 is connected to the rear plate 18 via the second clevis 8a.

The other ends of the first and second toggle pieces 7 and 8 of the toggle mechanism 9 are respectively connected to the guide block 1 described later.
2 is pivotally and slidably connected. Further, one end of a pair of rods 19 and 20 is connected to the rear plate 18, and the other end of each rod 19 and 20 is connected to the first mold holding body 17 to which the first mold part 2 is attached. It is connected.

The guide block 12 is provided with a pair of center positioning guide bars 13 by a feed screw body 16 such as a ball screw which is rotated by an electric motor 15 for opening and closing a toggle.
It is configured so that it can be reciprocated in a direction (Y-axis direction) perpendicular to the center axis direction (X-axis direction) of the mold by being guided by 14.

Next, the connecting portion 34 between the other ends of the first and second toggle pieces 7 and 8 and the guide block 12 will be described with reference to FIG.

At the other ends of the first and second toggle pieces 7 and 8, spindles 31 and 31 to which the first and second toggle pieces 7 and 8 are rotatably connected are inserted. This support shaft 31,
Guide pieces 36, 36 are provided above and below 31. The guide pieces 36, 36 are arranged at right angles to the moving direction of the guide block 12 (Y-axis direction).
Is slidably connected to a guide portion 37 provided on the. The guide portion 37 is composed of a rail, a groove, or the like. Further, a roller bearing 32 as a rotating body is fitted in the central portion of each of the support shafts 31, 31. As described above, the first and second toggle pieces 7, 8
A connecting portion 34 (see FIG. 3) is configured by an end portion of the guide portion 37 and the guide portion 37 provided on the guide block 12.

Next, as shown in FIGS. 1 to 3, the guide block 12 is provided with a wedge portion 35.
In the wedge portion 35, a wedge 35a screwed into a feed screw body 38 such as a ball screw which is rotated by an electric motor 39 for direct mold clamping is provided with a wedge 35a via a support body 33 and a pair of center positioning guide bars 41 and 42. And is reciprocated in the Y-axis direction. A thrust bearing 40 is provided at the end of the feed screw body 38. Both sides of the wedge 35a are tapered, and the wedge 35a can be inserted between the roller bearings 32 and 32 fitted to the support shafts 31 and 31, respectively.

Next, the operation of this embodiment will be described.

In the above-described structure, the guide screw 12 is rotated by the electric motor 15 for opening and closing the toggle to move the guide block 12, so that the guide block 12 moves in the Y-axis direction as shown in FIG. The stroke advances, and each toggle piece 7, 8 advances from the refracted shape to a straight shape along the positions indicated by the two-dot chain line and the solid line, and advances the T stroke in the X-axis direction. As a result, the mold holders 10 and 17 move in the direction in which they are joined to each other, so that the mold parts 2 and 3 are closed, but they are not completely closed, and there is a gap of dimension A in the drawing. Existing. In the past, this A dimension was a manually adjusted dimension.

When the toggle pieces 7 and 8 are in a straight line, that is, when the toggle pieces 7 and 8 coincide with the central axis direction of the mold, the electric motor 39 for direct mold clamping is formed.
Thereby, the feed screw body 38 is rotated to move the wedge 35a. As a result, the wedge 35a has the first,
The support shaft 31, to which the other ends of the second toggle pieces 7 and 8 are connected,
Roller bearings 32, 32 fitted in 31
Inserted in between. The other end of each of the first and second toggle pieces 7 and 8 is moved along the guide portion 37 while the roller bearings 32 and 32 rotate in accordance with the angle of the tapered surface of the wedge 35a. ) And move to the mold parts 2, 3
The A dimension between them becomes 0.

Further, when the electric motor 39 is rotated, the torque is increased, and the force due to this torque is transmitted to the mold parts 2 and 3 through the first and second toggle pieces 7 and 8 to provide an appropriate mold clamping force. Is obtained. In this way, the wedge 35a is moved from the initial contact state with the roller bearings 32, 32 by the S stroke in the drawing, whereby the mold is clamped.

Further, the mold opening operation is the reverse of the above operation, and the wedge motor 3 is used by the electric motor 39 for direct mold clamping.
5a is retracted by S stroke, then the guide block 12 is retracted by L stroke by the electric motor 15 for opening and closing the toggle, and each toggle piece 7, 8 is bent straight along the positions shown by the solid line and the chain double-dashed line. As a result, the mold opening operation is performed. In this embodiment, the electric motor is used as the drive means for opening and closing the toggle and the direct mold clamping, but a hydraulic or pneumatic cylinder may be used.

[0028]

The mold clamping device of the blow molding machine according to the present invention comprises:
Since it is configured as described above, the following effects can be obtained. That is, since the wedge portion driven by the electric motor or the like is provided, (a) it is not necessary to manually adjust the mold thickness, and the working time can be shortened. Further, even if the thickness accuracy of the mold is poor, the mold can be clamped without any problem. (B) The mold clamping force is variable as long as it is within the output of the electric motor, and an appropriate mold clamping force can be easily obtained. (C) Since the mold clamping speed is variable as long as it is within the output of the electric motor, etc., the cut-off state of the parison is stabilized. (D) When the mold is clamped via the toggle mechanism, there is no step on the joint surface of both mold parts of the mold and the cut-off part of the parison, so that the quality can be improved.

[Brief description of drawings]

FIG. 1 is an operation view of a mold clamping device of a hollow molding machine according to the present invention as seen from a plane side.

FIG. 2 is a front view of FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a front view of a mold clamping device of a conventional blow molding machine.

FIG. 5 is a plan view of FIG.

[Explanation of symbols]

 1 mold 2 first mold part 3 second mold part 4 extruder 5 crosshead 6 parison 7 first toggle piece 8 second toggle piece 9 toggle mechanism 10 second mold holder 11 shaft support 12 guide block 13 , 14 Guide bar 15,39 Motor 16,38 Feed screw 17 First mold holder 18 Rear plate 19,20 Rod 21 Connection 31 Support shaft 32 Roller bearing (rotating body) 33 Support 34 Connection 35 Wedge 35a Wedge 36 Guide piece 37 Guide part 40 Thrust bearing 41,42 Guide bar 50 Mold open / close interlocking mechanism

Claims (4)

[Claims] 1. A guide block (12) to which first and second toggle pieces (7, 8) are rotatably and slidably connected, respectively, is advanced to move the first and second toggle pieces (7). ，
After making 8) straight, insert a wedge (35a) between both ends of the first and second toggle pieces (7, 8) whose ends are connected to the guide block (12). Then, the mold clamping method for the hollow molding machine is characterized in that the mold clamping is performed by moving the first and second toggle pieces (7, 8). 2. A guide block (12) reciprocating in a direction perpendicular to the mold opening and closing direction, and the guide block (1).
2), a toggle mechanism (9), a first die holder (17) for holding the first die part (2), and a second die connected to one end of the toggle mechanism (9). A second mold holder (10) for holding the part (3), and the toggle mechanism (9)
And a pair of rods (19, 2) having one end connected to the rear plate (18) and the other end connected to the first mold holder (17).
0) and a mold clamping device of a hollow molding machine, the toggle mechanism includes a pair of bendable first and second toggle pieces (7, 8), and one end of the first toggle piece (7) is It is connected to the second mold holder (10), one end of the second toggle piece (8) is connected to the rear plate (18), and the other end of the first and second toggle pieces (7, 8). Are rotatably and slidably connected to the guide block (12) via support shafts (31, 31), respectively, and the support shafts (31, 31) respectively have rotating bodies (32, 32). The guide block (12) is provided between the rotating bodies (32, 32) arranged at the other ends of the first and second toggle pieces (7, 8) of the toggle mechanism (9). Hollow component characterized in that it is provided with a wedge part (35) with insertable wedges (35a) Machine of mold clamping device. 3. Guide pieces (36, 36) are provided above and below the support shaft (31, 31), and the guide pieces (36, 3) are provided.
The guide member (6) is slidably guided by a guide portion (37) provided in the guide block (12) in a direction perpendicular to the moving direction of the guide block (12). A mold clamping device for the hollow molding machine described. 4. The guide block (12) and the wedge (35a) of the wedge portion (35) are connected to respective electric motors (1) through respective feed screw bodies (16, 38).
The mold clamping device of the blow molding machine according to claim 3 or 4, characterized in that the mold clamping device is driven by a motor.