JPS6222348Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a mold clamping device for an injection molding machine in which a mold clamping cylinder is attached to a tie bar that holds a movable mold placement plate.

A mold clamping device in which a mold clamping cylinder is provided on the diagonal of a movable mold placing plate and a tie bar inserted into the mold clamping cylinder is also used as a piston rod is disclosed in Japanese Patent Application Laid-Open No. 1973-
It is already known from the publication No. 71356. In this known mold clamping device, an oil chamber for rapid feed is provided in the tie bar, so the structure of the tie bar is not only more complicated than that of a normal direct pressure type, but also rapid feed is limited to only when the mold is opened. There were flaws.

This idea was devised to eliminate the above-mentioned drawbacks of the conventional method, and its purpose was to simplify the structure of the tie bar while also using part of the tie bar as a piston rod for mold clamping and rapid feed. In addition, by operating the mold clamping cylinder and rapid feed cylinder individually installed on the movable mold stand, rapid feed can be performed not only when the mold is opened, but also when the mold is closed. Another object of the present invention is to provide a mold clamping device with a new structure that can quickly perform processes such as mold clamping.

This invention for the above purpose consists of tie bars arranged in parallel at the four corners of a fixed type placing plate, a movable type placing plate slidably held by the tie bars, and four corners of the back of the movable type placing plate through which the tie bars penetrate. 2 on the diagonal
A rapid-forwarding cylinder and a mold-clamping cylinder are provided in positions based on each other, a piston is provided in a portion of the tie bar existing in each cylinder, and a piston is provided in each oil chamber partitioned by the piston via the tie bar. The gist of the system is that it consists of a hydraulic circuit.

This invention will be explained in detail below using illustrated examples.

1 is a fixed type mounting plate with tie bars 2, 2 installed in parallel at the four corners. A movable mold placing plate 3 is slidably attached to the tie bars 2, 2, and the molds 4, 5 are opened and closed by the movement of the movable mold placing plate 3, and the molds are clamped.

At the four corners of the back of the movable mold placement plate 3 through which the tie bars 2, 2 pass, rapid feed cylinders 6 and mold clamping cylinders 7 are arranged alternately so that two cylinders are located diagonally, as shown in FIG. Pistons 8 and 9 are integrally attached to the portions of the tie bars 2 and 2 that are provided within the cylinders.

Further, inside each tie bar 2, 2, a part of hydraulic passage 10, 11 is bored, which communicates with two oil chambers in each cylinder partitioned by pistons 8, 9, respectively.

In the figure, 12 is a tie bar support plate, and 13 is an opening prevention plate provided over the ends of the mold clamping cylinders 7, 7.

In the mold clamping device having the above structure, since both the fast feed cylinder 6 and the mold clamp cylinder 7 are provided on the movable mold placing plate 3, pressure oil is supplied from the tie bar 2 to the fast feed cylinder 6, and the mold clamping device is moved. Together with the mold placement plate 3, the mold 5 can be fast-forwarded to the mold 4 on the fixed mold placement plate 1 to close the mold, and after the mold is closed, pressure oil is supplied from another tie bar 2 to the mold clamping cylinder to close the mold. Strong mold clamping of molds 4 and 5 can be performed continuously.

As mentioned above, this idea involves positioning two rapid feed cylinders 6, 6 and two mold clamping cylinders 7, 7 diagonally at the four corners of the back of the movable mold placement plate 3 through which the tie bars 2, 2 pass. In addition to providing
Pistons 8 and 9 are provided in the portions of the tie bars 2 and 2 that exist within each cylinder, so that the rapid feed cylinders 6 and 6 and the mold clamping cylinders 7 and 7 are operated individually by pressure oil from the tie bars. Therefore, unlike conventional equipment, there is no need to provide an oil chamber for rapid feed inside the tie bar, and there are fewer hydraulic paths.
Not only is the structure of the tie bar simplified, making it easier to manufacture the tie bar, but the diameter of the tie bar is also smaller, making it possible to downsize the device. Rapid feed is also performed not only when the mold is opened, but also when the mold is closed. It has extremely advantageous features in terms of the molding cycle.

[Brief explanation of the drawing]

The drawings show a mold clamping device for an injection molding machine according to this invention, in which FIG. 1 is a partially longitudinal side view, and FIG. 2 is a sectional view taken along the line of FIG. 1. 1... Fixed type placing plate, 2... Tie bar, 3... Movable type placing plate, 6... Rapid feed cylinder, 7... Mold clamping cylinder, 8, 9... Piston.

Claims (1)

[Scope of utility model registration request] Tie bars are installed in parallel at the four corners of the fixed type placing plate, and a movable type placing plate is slidably held by the tie bars.
fast-forwarding cylinders and mold-clamping cylinders, two of which are located diagonally at each of the four corners of the back of the movable mold placement plate through which the tie bars pass; and pistons that are provided in the portions of the tie bars that exist within each cylinder. , and a hydraulic circuit disposed in each oil chamber partitioned by the piston via the tie bar.