JPH0342995Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to an ejector device used in an injection molding machine to take out a molded product from a mold.

"Prior Art" In recent years, electric injection molding machines using servo motors and the like have come to be manufactured alongside conventional injection molding machines using hydraulic pressure as a drive source. Most of the ejector devices of this type of injection molding machine are of a mechanical type as shown in FIG. 2, but an electric type as shown in FIG. 3 is also known. In the former mechanical device, when the movable platen 1 moves in the mold opening direction indicated by arrow A in the figure, the ejector plate 2
collides with the fixed bar 4 fixed to the end plate 3 and moves relatively in the mold closing direction B, and the ejector pin 5 ejects the molded product. In addition, in the latter electric device, the rotational force of the electric motor 6 provided at the bottom of the movable plate 1 is transmitted from the timing pulley 7 to the timing belt 8 to the timing pulley 9 to
Ball screw 10, then Ball screw 10
As a result, the ejector plate 2 moves in the mold closing direction B, and the ejector pin 5 projects the molded product.

"Problems to be solved by the invention" However, in the mechanical ejector device described above, the amount of protrusion of the ejector pin 5 is determined by the position of the fixed bar 4 and the amount of mold opening of the movable platen 1. However, when performing multi-stage ejection, the movable platen 1 must be moved multiple times.
When complex ejector operations are required, there are problems such as poor response and movement of the mold when ejecting the molded product. In addition, a device equipped with an electric motor 6 can perform complex ejector operations, but since the electric motor 6 is provided on the moving board 1, there is a problem that the weight of the moving part increases. .

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ejector device for an injection molding machine that can perform complicated ejector operations and does not increase the weight of moving parts.

"Means for Solving the Problem" In order to achieve the above object, the present invention provides a fixed platen to which a fixed die is attached and a movable platen to which a movable die is attached, which are arranged with their die attachment surfaces facing each other. An end plate is disposed opposite to the surface of the movable platen opposite to the mold mounting surface, and the end plate is provided with a first transmission mechanism to move the movable platen in the mold opening/closing direction. In an injection molding machine equipped with an electric motor for movement, an ejector plate is disposed so as to be movable in the mold opening/closing direction facing the surface of the movable plate opposite to the mold mounting surface, and the ejector plate is movable in the mold opening and closing direction. , an ejector pin that penetrates the movable plate and retracts into the movable mold as the ejector plate moves is fixedly provided, and the ejector plate is connected to the electric motor and is driven by the electric motor. A second transmission mechanism that moves the ejector plate in the mold opening/closing direction by force is attached, and a driving force of the electric motor is transmitted to the first transmission mechanism between the electric motor and the first transmission mechanism and the second transmission mechanism. It is configured by disposing a switching means for transmitting the signal to the second transmission mechanism.

"Operation" In the above configuration, when the mold is opened and closed, the driving force from the electric motor is transmitted to the movable platen through the first transmission mechanism, and the movable platen is moved in the mold opening and closing direction. On the other hand, when ejecting the molded product, the switching means operates to switch the driving force of the electric motor to the second transmission mechanism, which moves the ejector plate and causes the ejector pin to eject the molded product. conduct.

"Embodiment" An embodiment of the present invention will be described below with reference to FIG.

In the figure, 20 is a movable board on which a movable mold (not shown) is attached to a mold mounting surface 20a.
In front of the movable platen 20 (on the right side in the figure), a fixed platen (not shown) to which a fixed mold is attached is arranged with its mold mounting surface facing the mold mounting surface 20a of the movable platen 20. . Further, behind the movable platen 20 (on the left side in the figure), an end plate 22 connected to the fixed platen by a plurality of tie bars 21 is disposed facing the movable platen 20.
The movable board 20 is movably attached to 1.

Furthermore, a first nut member 24 having a first timing pulley 23 coaxially fixed to one end of the end plate 22 is provided on the end plate 22 .
3 is located at the rear of the end plate 22, passes through the end plate 22 back and forth, and is attached to the first nut member 24 so as to be rotatable with its axis directed in the mold opening/closing direction (horizontal direction in the figure). A first ball screw 25 whose front end (not shown) is connected to the movable platen 20 directly or via a toggle joint or the like is screwed. Also, end plate 2
2 is provided with an electric motor (servo motor) 26 with its output shaft 27 facing the rear of the end plate 22, and the output shaft 27 has a first electromagnetic clutch 28 and a second electromagnetic clutch 29 connected to the first electromagnetic clutch 28 and the second electromagnetic clutch 29. It is attached with the electromagnetic clutch 28 facing forward. A second timing pulley 31 connected to the first timing pulley 23 via a first timing belt 30 is rotatably supported on the output shaft 27, and a third timing pulley 32 is rotatably supported. has been done. The third timing pulley 32 is further connected via a second timing belt 35 to a fourth timing pulley 34 at the rear end of the first power transmission shaft 33, which is rotatably disposed with its axis directed in the mold opening/closing direction. The first transmission shaft 33
A spline hole 33 formed at the front end of this
A second transmission shaft 37 is coaxially attached via a spline shaft portion 36 fitted to the second transmission shaft 37, and a fifth timing pulley 38 is fixed to the second transmission shaft 37.

Furthermore, an ejector plate 39 is disposed behind the movable platen 20 so as to be movable in the mold opening/closing direction along a guide bar (not shown). A plurality of ejector pins 40 are provided which are fitted into the through holes 20b. A second nut member 41 is fixed to the ejector plate 39 with its axis oriented in the mold opening/closing direction, penetrating the ejector plate 39 back and forth, and having its front end attached to the second nut member 41 via a connecting shaft 42. A second ball screw 43 is rotatably attached to the movable platen 20 and is screwed therein. Then, the fifth
The third timing belt 4 is attached to the timing pulley 38.
A sixth timing pulley 45 communicated via 4
is fixed. Note that 46 in the figure indicates a bearing.

The first nut member 24, the first ball screw 25, the first and second timing pulleys 2
3, 31 and the first timing belt 30 constitute a first transmission mechanism 47, the third, fourth, fifth, and sixth timing pulleys 32, 34, 38, 45, the second and third timing belts 35, 44, the second nut member 41, the second ball screw 43, etc.
A transmission mechanism 48 is configured, and further includes the first and second
The electromagnetic clutches 28 and 29 constitute a switching means 49 for transmitting the driving force of the electric motor 26 to the first transmission mechanism 47 and to the second transmission mechanism 48.

In the ejector device having the above structure, the second electromagnetic clutch 29 is energized and the third timing pulley 32 is connected to the output shaft 27 when ejecting the molded product. The driving force from the electric motor 26 is transmitted through the third timing pulley 32 → second timing belt 35 → fourth timing pulley 34 → first transmission shaft 33 → second transmission shaft 37 → fifth timing pulley 38 → third timing belt 44 → Sixth timing pulley 45 → Connection shaft 42 → Second ball screw 43 → Second nut member 41 → Ejector plate 39.
The ejector plate 39 moves to the movable plate 2.
approaches 0. As a result, the ejector pin 40 penetrates the movable platen 20 and is projected into the movable mold, and the molded product is ejected from the mold.

Furthermore, when the mold is opened and closed, the first electromagnetic clutch 28 is excited and the second timing pulley 31 is connected to the output shaft 28.
7, and the driving force from the electric motor 26 is
It is transmitted to the first nut member 24 in this order: second timing pulley 31 → first timing belt 30 → first timing pulley 23 → first nut member 24.
Then, the first nut member 24 rotates to move the first ball screw 25 in the axial direction, thereby moving the movable platen 20 in the mold opening/closing direction either directly or via the toggle joint.

In the ejector device with the above configuration, the ejector operation is performed using the electric motor 26 for opening and closing the mold, so compared to conventional mechanical ejector devices, the weight of the moving part is lighter, and the toggle type In this case, there is no toggle involved, so
It is possible to perform more complex ejector operations and to obtain faster response, and
The movable plate 20 does not move when ejecting. Furthermore, compared to conventional ejector devices having a dedicated electric motor, the control system is simplified because a dedicated control system for the ejector motor is not required.

"Effects of the Invention" As explained above, the ejector device of the present invention does not use an electric motor dedicated to the ejector device, but uses the electric motor used for opening and closing the mold to perform the ejector operation. , capable of performing complex ejector operations,
It is possible to obtain quick response, simplify the control system, and reduce the weight of moving parts.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
FIG. 2 is a block diagram showing a conventional mechanical ejector device, and FIG. 3 is a block diagram showing a conventional electric ejector device. 26... Electric motor, 28... First electromagnetic clutch, 29... Second electromagnetic clutch, 47... First transmission mechanism, 48... Second transmission mechanism, 49... Switching means.

Claims (1)

[Scope of utility model registration request] A fixed platen to which a fixed die is attached and a movable platen to which a movable die is attached are arranged with their die attachment surfaces facing each other, and an end plate is placed opposite to the surface of the movable platen opposite to the die attachment surface. In an injection molding machine, the end plate is provided with an electric motor that moves the movable plate in the mold opening/closing direction via a first transmission mechanism, and the mold mounting surface of the movable plate is An ejector plate is disposed facing the opposite surface so as to be movable in the mold opening/closing direction. A second transmission mechanism is attached to the ejector plate, which is connected to the electric motor and moves the ejector plate in the mold opening/closing direction by driving force from the electric motor. and a switching means for transmitting the driving force of the electric motor to the first transmission mechanism or to the second transmission mechanism is disposed between the electric motor, the first transmission mechanism, and the second transmission mechanism. An ejector device for an injection molding machine characterized by: