JPS6233055B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coupling device for an ejection device of an injection molding machine.

A mechanically or fluidically operated ejector device of an injection molding machine has a driving part on the molding machine side and an operating part on the tool side. For removal of the tool (mold) (mold change), both parts of the ejection device must be separated and connected again after installation of the new tool (with a correspondingly new working part). It won't happen. Known coupling devices for parts of ejection devices are usually screws or threaded rods or bayonet joints. These all have the disadvantage that they have to be manually connected and released.

Nowadays, it has become possible to separate the working part of the ejector, which is journalled in the mold half, as easily as possible from the working part which remains in the molding machine, or to connect it to this working part. There is a need for an injection molding machine installation having a provision for changing tool units.

It is therefore an object of the invention to obtain a coupling device of the type mentioned at the outset, which can be installed and removed automatically.

For this purpose, the coupling device according to the invention comprises:
a transmission rod coaxial with the ejector piston of the mold-side working part of the ejector, which cooperates with a coupling member connected to the axially movable ejector piston of the machine-side drive part of the ejector; A clamping member is provided which is capable of a frictional connection with the transmission rod, and which releases the frictional connection with the conduction rod by actuation by a pressure medium of a coupling piston with which it is axially kinematically connected. It is characterized by the fact that it can be

The frictional connection between the clamping member on the ejector piston and the transmission rod can be mechanically formed, for example by means of a spring, or hydraulically.
Alternatively, it can be carried out by means of a pneumatically operable tightening piston. This clamping piston serves the purpose of serving to actuate a clamping wedge that can move axially;
This clamping wedge is adapted to be frictionally connected to the transmission rod in cooperation with a conical bushing fixed to the actuating piston, or to be able to be released from the connection.

Such a coupling device is easily automated by coupling its operating means to a control device that controls the exchange of molds.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 1 to 4 of the accompanying drawings showing embodiments thereof.

In FIG. 1, 1 is a fixed platen of a synthetic resin injection molding machine, and 2 is a movable platen that moves on tie bars 3. A stationary platen 1, to which is attached a plasticizing and injection unit (not shown), supports the mold half 4a, while a drive mechanism actuated via a fluidic device, which is designed as a toggle mechanism. 5a
The movable platen 2 connected to the other mold half 4b
is supported. Mold halves 4a, 4 removably attached to both fixed platen 1 and movable platen 2
b forms a tool (mold) unit of the molding machine which is replaceable as a whole. The mold half 4b, which is arranged on the movable platen 2, contains, in a known manner, the working part 6 of the hydraulic ejection device, while
The drive part 7 of this ejection device is mounted on the movable platen 2.

The working part 6 of the ejector device has a conventional ejector pin 9 which is ejectable into the mold space and is fixed to a pin support 8 lying in the chamber of the mold half 4b. have. A conducting rod 10 coaxial with the injection axis a projects away from the pin support 8 through an opening in the rear wall of the mold half 4b. On the opposite side of the movable platen 2 from the mold, there is a fluid cylinder 1 of the driving part 7 of the ejecting device.
1 is installed. A double-acting, ejecting piston 12 is introduced into the cylinder 11 and is coaxial with the injection axis a. Extrusion piston 1
The head bush 13 of the piston rod 14 protruding into the through opening of the movable platen 2 of No. 2 is provided with a closing disc 15 on the front side. Boss 15a protruding inside
have. The center hole of the disk 15, whose diameter is slightly larger than the diameter of the conductive rod 10, is formed by the boss 15.
It is expanded into a conical shape in a. A radially outwardly corresponding conical wedge surface 16 for cooperating with the conical surface of the boss 15a.
a partially cylindrical clamping wedge 16 having a diameter and corresponding radially inwardly to the conducting rod 10;
is provided. The end portion of this tightening wedge 16 on the opposite side from the boss 15a has a wedge surface 16
The boss 1 is formed in a conical shape in the opposite direction to the head bush 13 and is located in the space of the head bush 13.
It is in close contact with the connecting piston 17 guided above 5a. This connecting piston 17 is moved by a spring 18 supported at the bottom of the head bushing 13 into a conical boss 15a.
The load is applied in the direction of pushing it into the . Disk 15
and the connecting piston 17, there is a head bush 1.
cylinder chamber 2 connected to a fluid pressure source (not shown) of the molding machine via a conduit 19 in 3;
0 is formed. A drive plate 21 radially engaging the clamping wedge 16 and the coupling piston 17 creates an axial movement connection of these elements 16,17.

When the injection molding machine is in operation, the head bush 13
The coupling devices 15 to 21 housed in the ejector connect the working part 6 of the ejection device to its drive part 7 in the following manner.

When the cylinder chamber 20 is relieved of pressure, the spring 18 is in this case connected via the connecting piston 17 to the incoming conduction rod 1 of the working part 6.
The clamping wedge 16 lying on top of 0,
Pressing against the conical boss 15a of the disk 15, this clamping wedge 16 is compressed firmly in the radial direction onto the conducting rod 10. Therefore, between the conduction rod 10 and the piston rod 14,
Therefore, the actuating part 6 and the driving part 7 of the ejection device
A strong axial connection is created between them by means of a frictional connection. Due to the corresponding fluid actuation of the ejector piston 12, the ejector device, i.e. its pin 9, is therefore rapidly ejected or retracted in response to the working cycle of the forming machine.

Now, if the tool unit, ie both mold halves 4a, 4b, are to be replaced, a spring 18 is inserted into the cylinder chamber 20 via the conduit 19.
A fluid pressure is generated which overcomes the force of , whereby the connecting piston 17 is moved correspondingly away from the disc 15 . In this case, the clamping wedge 16 is released from its clamping position in the conical boss 15a by means of the drive plate 21, so that the frictional connection with the transmission rod 10 is removed. Thereafter, after the removal of the mold half 4b from the movable platen 2, a corresponding opening movement of this movable platen 2 (to the right in the figure) causes the drive part 7 of the ejection device to connect with the coupling device. axially away from the transmission rod 10 until the tool unit can be replaced without any problems with the working part 6 of the ejection device arranged in the mold half 4b (first Figure 3). After installation of a new tool unit, the course is correspondingly reversed, i.e., the coupling piston 17 is tightened by a corresponding closing movement of the movable platen 2 when the coupling piston 17 is loaded with pressure in the direction of release of the coupling device. The wedge 16 is moved over the conduction rod 10 and, by unloading the connecting piston 17, the spring 18 is actuated again;
It will be understood that the desired frictional connection between the actuating part 6 and the drive part 7 is again created via the clamping wedge 16 and the conical boss 15a. The loading or unloading of the connecting piston 17 with the pressure medium can be easily controlled, so that the entire process of separating and connecting the projecting parts 6, 7 can be reliably automated.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the tool unit of the injection molding machine with the movement and closing drive mechanism, and FIGS. 2 and 3 show the ejection device of the molding machine shown in FIG. FIG. 4 is an enlarged longitudinal sectional view showing the coupling device in the engaged state. 2...Movable plate; 4a, 4b...Mold half; 6...
... Working part; 7... Drive part; 10... Conduction rod; 12... Extrusion piston; 15... Disc;
15a... Boss; 16... Tightening member; 17...
...Connection piston; 18...Spring; 21...Thin metal plate.

Claims (1)

[Scope of Claims] 1. The operating part 6 of the ejection device is placed in a mold half 4b that is removably fixed to the movable platen 2,
Further, the driving part 7 of the ejecting device is mounted on the movable platen 2,
In each case, in a coupling device for an ejector device of an injection molding machine arranged, an ejector piston cooperates with a coupling member 15a connected to an axially movable ejector piston 12 of a drive part 7 on the machine side of the ejector device. A clamping member 16 is provided which is connectable to the conduction rod 10 of the actuating part 6 of the mold half 46 side of the ejection device coaxial with respect to 12, to which the clamping member 16 is axially kinematically connected. A coupling device characterized in that the coupling piston 17 can be released from the frictional connection with the transmission rod 10 by actuation of the coupling piston 17 by a pressure medium. 2. Connecting member 15a that cooperates with tightening member 16
is a boss 15a provided with a conical hole in the disc 15 closing the head bush 13 arranged at the end of the piston rod 14 of the ejector piston 12; A spring 18, which is provided with an outer surface of the clamping member 16 lying on the transmission rod 10 in the coupling position, engages the coupling piston 17 for frictional connection with the transmission rod 10 The coupling device according to claim 1, wherein the coupling device is adapted to be press-fitted into the boss 15a in the axial direction by a screw. 3 a spring-loaded coupling piston 17 lies against a correspondingly conical outer surface of the clamping member 16 by a conical inner surface in the opposite direction to the conical boss hole; This clamping member 16 is adapted to be moved out of engagement with the conical boss 15a via the rotary metal plate 21 when the connecting piston 17 is actuated by the pressure medium. The coupling device according to scope 2.