JPH068295A - Clamping method and device in injection molding machine - Google Patents

Abstract

PURPOSE:To eliminate the need for a high-precision screw machining, enhance a reliablity, and lower a cost by fastening a tie bar to a die plate by a resilient force of resilient bodies provided on the tie bar. CONSTITUTION:A tie bar 3 is provided through a mounting hole 2 formed in a first die plate 1. An end part 3a of the tie bar 3 is positioned in a recessed part 15 formed in a first die plate 1. In the recessed part 15, a plurality of resilient bodis 16 of, e.g., ring-form belleville springs having a non-flat shape as a whole to serve as locking rings are provided in a laminated state. The end part 3a of the tie bar 3 is inserted through a center hole 16a of the resilient bodies 16. A retaining ring 18 is provided on the end part 3a through a spacer ring 17. The resilient bodies 16 are contained between the spacer ring 17 and a bottom part 15a of the recessed part 15 in a depressed state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for clamping a mold of an injection molding machine, and more particularly to a new improvement for fastening a mold plate and a tie bar without threading the tie bar.

[0002]

2. Description of the Related Art As a mold clamping device of an injection molding machine of this type that has been used conventionally, the structure shown in FIG. 5 has been generally adopted. That is, what is indicated by reference numeral 1 in FIG. 5 is a mold plate, and a tie bar 3 is provided so as to penetrate through a mounting hole 2 formed in the mold plate 1.

A nut 5 is screwed into the tie bar screw portion 4 of the tie bar 3 penetrating the mounting hole 2, and a through hole 6 formed in the axial direction is formed on the peripheral edge of the nut 5. . A holding plate 7 having a plurality of guide holes 7a (only one is shown in the figure) is placed on the outer end 3b of the tie bar 3 to prevent the nut 5 from loosening, and is inserted into the guide hole 7a. The attached mounting bolt 8 penetrates the through hole 6 and is screwed into the screw hole 1 a of the template 1. Therefore, the tie bar 3 and the mold plate 1 are fastened to each other by the tie bar screw portion 4, the nut 5, the holding plate 7 and the bolt 8.

[0004]

Since the conventional mold clamping device of the injection molding machine is constructed as described above, the following problems exist. That is, both ends of the tie bar must be threaded to form the threaded portion, and
Since high precision is required for the processing, the tie bar itself is expensive. Also, when a mold clamping device consisting of a mold board and tie bar is loaded with mold clamping force, stress concentration may occur on the tie bar screw part, and accidents such as tie bar cutting may occur, ensuring tie bar strength. In order to do so, the diameter of the tie bar must be increased, resulting in an increase in the size of the entire device.

The present invention has been made in order to solve the above problems, and in particular, a mold clamping method for an injection molding machine in which the mold plate and the tie bar are tightened without threading the tie bar, and The purpose is to provide a device.

[0006]

A method for clamping a mold of an injection molding machine according to the present invention is a method of clamping a mold board and a tie bar, wherein the elastic body provided on the tie bar is elastic. It is a method of fastening the template and the tie bar by force.

A mold clamping device for an injection molding machine according to the present invention is a mold clamping device for an injection molding machine, wherein a mold plate and a tie bar are fastened to each other. A plurality of non-flat elastic bodies that are provided inside and through which the tie bar penetrates; and a holding plate that is provided on the mold board and presses the outer ends of the tie bars, and the elastic force of the elastic body is used. This is a configuration in which the template and the tie bar are fastened together.

More specifically, the elastic body is composed of a plurality of ring-shaped disc springs.

More specifically, the elastic body has a plurality of slits formed in the diameter direction.

[0010]

In the method and apparatus for clamping a mold of an injection molding machine according to the present invention, a tie bar is provided so as to penetrate an elastic body provided in a recess formed in a mold board, and an outer end of the tie bar is pressed by a pressing plate. Has been. Therefore, due to the pressing force of the pressing plate, the elastic body is deformed from the non-flat shape to the flat shape, and the tie bar is clamped by the elastic force. In addition, a mold clamping force is applied to the mold clamping device and a load acts in the direction of pulling out the tie bar, the elastic body exerts a self-locking function, and the tie bar can be more firmly tightened.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a mold clamping method and apparatus for an injection molding machine according to the present invention will be described in detail below with reference to the drawings. In addition, the same or equivalent portions as those of the conventional example will be described using the same reference numerals. 1 to 4 show a mold clamping device of an injection molding machine according to the present invention, FIG. 1 is a front view with a partial notch showing the mold clamping device, and FIG. 2 is an enlarged sectional view of part A of FIG. 3 is an enlarged plan view showing the elastic body shown in FIG. 1, and FIG. 4 is shown in FIG.
It is sectional drawing by the BB line of FIG.

In FIG. 1, reference numeral 1 designates four pieces (only two pieces are shown in the figure) provided via a fixed platen 10.
The first die plate 1 is provided on the upper part of the tie bar 3, and the first die plate 1 is provided with the first die part 11.

A second mold plate 12 is provided below each tie bar 3.
In addition, the second mold plate 12 is provided with a mold clamping ram 13a, and a mold clamping cylinder 13 that houses the mold clamping ram 13a is provided on the fixed platen 10. The stationary platen 10 is provided with a second mold part 14.

The fastening structure of the tie bars 3 and the mold plates 1 and 12 is configured as shown in A portion of FIG. 1 and FIG. 2, and since they are all the same structure, the above-mentioned FIG. The structure of only part A will be described. The tie bar 3 is provided so as to penetrate through the mounting hole 2 formed in the first die plate 1, and the end portion 3a of the tie bar 3 is located in the recess 15 formed in the first die plate 1. There is.

Inside the recess 15, the entire shape is formed to be non-flat, and for example, elastic bodies 16 as a plurality of lock rings composed of ring-shaped disc springs are provided in a laminated state. The end portion 3a of the tie bar 3 is located in the center hole 16a of the pier bar 16 so as to penetrate therethrough. The inner diameter of the center hole 16a is set to be slightly larger than the outer diameter of the tie bar 3.

A retaining ring 18 is provided on the end portion 3a through a spacer ring 17, and the spacer ring 17 is provided.
The elastic body 16 is housed in a state in which the elastic body 16 is pressed into contact with the bottom 15a of the recess 15. In addition, the elastic body 1
As shown in FIGS. 3 and 4, the reference numeral 6 denotes a plurality of slits 16 along the diameter direction from the outer peripheral portion 16A and the inner peripheral portion 16B sides.
b is formed.

A pressing plate 7 is provided on the outer end 3b of the tie bar 3.
Is provided, and the holding plate 7 penetrates the guide hole 7a of the holding plate 7 and is screwed into the screw hole 1a of the first mold plate 1 (four bolts are actually used). By first
It is fixed to the mold board 1. Therefore, the protrusion of the tie bar 3 from the first mold plate 1 is pressed by the pressing plate 7.

Next, in the above structure, the mounting bolt 8
By tightening, each elastic body 16 is deformed from the non-flat shape to the flat shape by the pressing plate 7 and the tie bar 3 is clamped. Further, when a mold clamping force is applied through the mold clamping cylinder 13 and the mold clamping ram 13a of the mold clamping device 20 shown in FIG. 1 and the load acts in the direction of pulling out the tie bar 3, each elastic body 1
6 has a self-locking function and is more solid with tie bar 3
Can be concluded.

The elastic body 16 has been described using a disc spring, but a spring having another structure can be used as long as it has an equivalent function. Further, although the injection molding machine has been described as having a vertical structure, the same effect can be obtained not only in the vertical type but also in the horizontal type. Further, although the elastic body 16 has been described in the case where a plurality of lock rings are stacked, it may be configured by one.

[0020]

Since the mold clamping method and apparatus of the injection molding machine according to the present invention are configured as described above, the following effects can be obtained. That is, since the template and the tie bar are fastened via the elastic force of the spring member made of an elastic body, it is not necessary to perform high-precision screw machining as in the conventional case,
It is possible to improve reliability and reduce costs. Further, since screw processing is unnecessary, it is possible to prevent accidents due to stress concentration in the conventional screw portion.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing a mold clamping device of an injection molding machine according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a portion A of FIG.

FIG. 3 is an enlarged plan view showing the elastic body of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a cross-sectional view showing a main part of a conventional mold clamping device.

[Explanation of symbols]

 1 Mold board 3 Tie bar 3b Outer edge 7 Holding plate 15 Recessed portion 16 Elastic body 16b Slit

Claims (4)

[Claims] 1. A mold clamping method for an injection molding machine, wherein a mold plate (1) and a tie bar (3) are clamped together.
A mold clamping method for an injection molding machine, characterized in that the mold plate (1) and the tie bar (3) are clamped by an elastic force of an elastic body (16) provided in the. 2. A mold clamping device of an injection molding machine, wherein a mold plate (1) and a tie bar (3) are clamped together, a recess (15) provided in the mold plate (1) and in which the tie bar (3) is located. ), A non-flat elastic body (16) provided in the recess (15) and penetrated by the tie bar (3), and an outer end (3b) of the tie bar (3) provided in the mold plate (1). ) Is provided with a pressing plate (7),
A mold clamping device for an injection molding machine, characterized in that the mold plate (1) and the tie bar (3) are clamped via the elastic force of the elastic body (16). 3. The mold clamping device for an injection molding machine according to claim 2, wherein the elastic body (16) is composed of a plurality of ring-shaped disc springs. 4. The mold clamping device of an injection molding machine according to claim 2, wherein the elastic body (16) has a plurality of slits (16b) formed in a diameter direction.