JP3299683B2 - Mold clamping device for blow molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping device for a hollow molding machine. In addition, the present invention relates to a novel improvement for preventing a displacement of a mating surface of a mold due to a temporal change.

[0002]

2. Description of the Related Art As a conventional mold clamping device for a hollow molding machine of this type, for example, the structure disclosed in Japanese Patent Application Laid-Open No. 6-869 shown in FIGS. . That is, what is indicated by reference numeral 1 in FIGS. 3 and 4 is a mold that can be opened and closed and includes a first mold part 2 and a second mold part 3. Parison 6 hanging from crosshead 5 of machine 4
Is configured to be supplied. The second mold part 3
Is connected to a toggle mechanism 9 comprising 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 that is connected to bend freely is configured to be guided by a pair of center positioning guide bars 13 and 14. The guide block 12 is configured to be able to reciprocate in the axial direction by a feed screw body 16 such as a ball screw rotated by an electric motor 15, and the first mold part 2 includes a first mold holder 17.
Is provided. 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 and 20 is connected to the first mold holder 17. The rod 19 is fixedly connected to the connecting body 21, and the rod 19 operably penetrates the second mold holding body 10, and is connected to the rear plate 1.
8, a mold opening / closing interlocking mechanism 50 for the mold 1 is constituted by the rods 19, 20 and the connecting body 21. Accordingly, by operating the electric motor 15 and moving the guide block 12 with the feed screw body 16 in the above-described configuration, each of the toggle pieces 7 and 8 is straightened along the position indicated by the dotted line and the solid line as shown in FIG. In the case of a straight shape, each of the mold holders 10 and 17 is connected via a mold opening / closing interlocking mechanism 50.
Move in the direction in which they are joined to each other.
Is closed, and in the case of a bent shape, the mold parts 2 and 3 are opened in reverse to the above.

[0003]

The conventional mold clamping device for a blow molding machine has the following problems because it is constructed as described above. That is, since each toggle piece of the toggle mechanism operates linearly and in a bent manner in a horizontal direction perpendicular to the hanging direction of the parison as shown in FIG. 4 to open and close the mold, as shown in FIG. (2) Since the mold holder is inclined to the left, if the pins or holes (not shown) for positioning the mold are not worn, no displacement of the mating surface of the mold occurs. There is no discrepancy in the parting line of the molded product, but if these pins or holes become worn, play will increase, and a gap will occur between the mold parts of the mold, and the parting line will not be caught. A difference occurs, resulting in molding failure. In addition, the upper and lower burrs of the molded article after the molding cannot be cut off, and the molded article has whiskers, resulting in frequent occurrence of defects.

The present invention has been made to solve the above problems, and in particular, by opening and closing a mold through a toggle mechanism driven by an electric motor, a smooth and high-precision opening of a molded product without contamination is achieved. An object of the present invention is to provide a mold clamping device for a hollow molding machine that performs clamping and prevents displacement due to a change with time of a mold mating surface.

[0005]

According to the present invention, a mold clamping apparatus for a blow molding machine includes a parison hanging from a crosshead.
In a mold clamping device of a hollow molding machine which is held by a mold to be opened / closed and clamped through a mold opening / closing interlocking mechanism to obtain a hollow molded product, a rear plate of the mold opening / closing interlocking mechanism and the mold are provided. A toggle mechanism comprising first and second toggles provided in series between a second mold holder for holding a second mold portion, wherein the first and second toggles of the toggle mechanism are The mold is opened and closed by bending while moving up and down in the vertical direction along the direction in which the parison hangs.
It is configured to rotate via gears that mesh with each other.

More specifically, each toggle is performed by an electric motor.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a mold clamping device for 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 FIGS. 1 and 2, what is indicated by reference numeral 1 is an openable and closable mold including a first mold part 2 and a second mold part 3, and a cavity 1a of the mold 1 includes:
The parison 6 hanging from the crosshead 5 of the extruder 4 is configured to be supplied in the vertical direction. The second mold part 3 is connected to a first toggle 7 composed of a pair of bendable toggle pieces 7A and 7B via a second mold holder 10 and a first clevis 7a. 1st and 2nd rotatably mesh with the bracket 101 fixed to the side.
The toggle piece 7B of the first toggle 7 is connected to the first gear 102 of the gears 102 and 103. The second gear 10
The toggle piece 8B of each of the toggle pieces 8A and 8B of the second toggle 8 connected to 3 is connected to a rear plate 18 via a second clevis 8a, and a pair of rods 19 and 20 are connected to the rear plate 18. Each of the rods 19 and 20 is fixedly connected to a connecting body 21 connected to the first mold holder 17, and the rod 19 operatively penetrates the second mold holder 10. I have. A toggle mechanism 9 is constituted by the toggles 7 and 8, and a mold opening / closing interlocking mechanism 50 for the mold 1 is constituted by the rear plate 18, the rods 19 and 20, the toggle mechanism 9 and the connecting body 21. Therefore,
The first and second toggles 7 and 8 are arranged in series between the second mold holder 10 and the rear plate 18. The second gear 103 is connected to an electric motor 15 such as an AC servomotor via a first coupling 15c, a reduction gear 15b, and a second coupling 15a. Therefore,
The toggle mechanism 9 is configured to be able to open and close the mold by bending and operating while vertically moving along the direction in which the parison 6 hangs. The gears 102 and 103 are rotated and positioned so as to synchronize with the toggles 7 and 8 and to make the mating surface (parting line) of the mold 1 always the same (close to the same position). .

Next, the operation will be described. First, when the motor 15 is operated in a state where the parison 6 is pushed out from the cross head 5 and hangs down, the gears 102 and 103
By changing the posture of the first and second toggles 7 and 8 from the bent state in FIG. 1 to the linear state in FIG. Type 1
Is closed and closed. In this mold clamping operation,
Since the second mold holder 10 is loaded downward from its initial weight due to its own weight, and the toggle mechanism 9 also acts in the vertical direction, the difference in the parting line due to the inclination of the second mold 3 as in the related art. Defects do not occur, and the yield can be improved.

[0009]

According to the present invention, a mold clamping device for a blow molding machine is provided.
With the above configuration, the following effects can be obtained. That is, since each toggle of the toggle mechanism moves up and down in the vertical direction, it is possible to prevent the mold from inclining when the mold is clamped. It is possible to prevent generation of burrs and wear of the mold pins and holes, thereby improving the yield and improving the life of the mold.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram showing a mold clamping state of FIG. 1;

FIG. 3 is a configuration diagram showing a mold clamping device of a conventional hollow molding machine.

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is an explanatory view showing an inclined state of a mold holding plate at the time of mold clamping in the configuration of FIG. 3;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mold 2 first mold part 3 second mold part 5 crosshead 6 parison 7,8 first and second toggle 9 toggle mechanism 18 rear plate 102,103 gear

Claims (2)

(57) [Claims] 1. A parison hanging from a crosshead (5)
(6), in a mold clamping device of a hollow molding machine, wherein a mold (1) for opening and closing and clamping the mold via a mold opening / closing interlocking mechanism (50) to obtain a hollow molded product, Open / close interlock mechanism
The rear plate (18) of (50) and the second mold part (3) of the mold (1)
A toggle mechanism (9) comprising first and second toggles (7, 8) provided in series between the second mold holder (10) and the second mold holder (10). The first and second toggles (7, 8) open and close the mold (1) by bending while moving up and down in the vertical direction along the direction in which the parison (6) hangs down, and each of the toggles (7, 8). , 8) is a mold clamping device for a hollow molding machine characterized by rotating through a pair of gears (101, 102) meshing with each other. 2. The mold clamping device for a blow molding machine according to claim 1, wherein each of the toggles (7, 8) is performed by an electric motor (15).