JP2000263602A - Ejector device for motor driven vertical injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispose two ejector rods at both sides of a screw assembly and to completely synchronize with the two rods by operating a plurality of ejector rods by one set of drivers through a linkage, and vertically and linearly differentiating the rods. SOLUTION: A ball screw shaft 32 is rotated by rotating a servo motor 31, and thus a ball unit 33 is converted into a vertically straight motion. A ball nut holder 34 guided to a guide post 37 is vertically moved by forwardly or reversely rotating the motor 31 in the vertically straight motion. The motion is transmitted to a link 39 through a link 38 connected to the holder 34, and transmitted to a shaft 42 by a link 40. An ejector rod 43 mounted at the shaft 42 by a screw 47 is vertically moved to operate an ejector plate 48. Since the rod 43 simultaneously operate the two links by one drive source, the two links are completely synchronized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ejector device for an electric vertical injection molding machine.

[0002]

2. Description of the Related Art An upper ejector of a conventional hydraulic vertical molding machine uses a hydraulic cylinder for each ejector rod as a drive source of two ejector rods, and connects these two ejector rods to a screw assembly. It was located on both sides. The operations of these two hydraulic cylinders need to be synchronized, and various measures have been taken to address this need. However, perfect synchronization could not be obtained after all because of the hydraulic drive. Further, if oil leaks from the hydraulic cylinder, a mold or a molded product disposed below the cylinder is contaminated, so that an electric drive system that does not use oil is desirable.

[0003]

SUMMARY OF THE INVENTION The present invention relates to an electrically driven ejector, in which two ejector rods under the above-mentioned conditions are arranged on both sides of a screw assembly, and the two ejector rods are completely synchronized. It is an object of the present invention to provide an ejector device that enables the following.

[0004]

(1) In an ejector device of an electric vertical injection molding machine, a plurality of ejector rods are operated by a set of driving devices via a link mechanism so as to operate vertically. (2) The driving device includes a driving means for performing a rectilinear motion, and a moving member attached to the driving means, and a link mechanism is provided with a plurality of links 38 attached to the moving member 34, and attached to the link 38; A link 39 pivotally supported by a pin 45a on a link mechanism support 45 mounted on the movable platen 1, and a link 4 pin-connected to an end of the link 39
And a shaft 42 that moves up and down guided by a guide plate 44 supported on the movable platen 1 by being pin-connected to the link 40.
It is composed of (3) In order to align the tip of the ejector rod 43, the ejector rod 43 is screwed into the shaft 42 supporting the ejector rod 43 so as to be adjustable. (4) Servo motor 31 and servo motor 3
1 and a ball screw shaft 32 attached to the ball screw shaft 3
The ball nut 33 is screwed into the ball nut 2.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to description of an ejector device of the present invention, a vertical injection molding device to which the ejector device of the present invention is applied will be schematically described with reference to FIGS. 5A shows a state when the mold is opened, and FIG. 5B shows a state when the mold is fully closed. 1 is a movable platen, 3 is a fixed platen. A toggle link mechanism 4 includes an upper link 4a and a lower link 4b. The upper link 4a is pin-connected to the fixed platen 3 at an upper portion thereof, and the lower link 4b
Is pin-connected to the toggle support 5 at its lower end.
The upper link 4a and the lower link 4b are joined by a pin 4c at an intermediate portion so as to be bendable.

The fixed platen 3 is supported on the top of the frame 10. The movable platen 1 and the toggle support 5 are fixed above and below a tie bar 2 penetrating the fixed platen 3. The lower link 4b, 4b forming the right and left pair which constitutes the toggle link mechanism 4 has a cross head 6 pin-connected and held horizontally via a short operating link 6a pin-connected to an intermediate portion thereof. A ball screw shaft 8 is attached to the crosshead 6 at an intermediate position via a bearing. The ball screw shaft 8 is screwed with the ball nut 7 supported by the toggle support 5, and the lower end thereof is
It is slidably engaged with a pulley 18 rotatably mounted on a support 17 fixedly mounted on the top 6. Reference numeral 11 denotes a servomotor supported by the frame 10, via a belt 13 wound around a pulley 12 driven by the servomotor,
The pulley 18 is driven. Reference numeral 14 denotes an injection device, and 15 denotes a nozzle unit.

FIG. 6 shows a detailed structure of the ball screw shaft 8 and its upper and lower parts in FIG. The ball nut 7 to which the ball screw shaft 8 is screwed is supported by the toggle support 5. A bearing 19 is provided at the center of the crosshead 6, and the upper end of the ball screw shaft 8 is rotatably supported by the crosshead 6 and fastened with a nut 20.

Next, a spline (male) 21 is provided below the ball screw shaft 8, and this is connected to the shaft 22 of the pulley 18.
Is slidably engaged with a spline (female) 23 provided on the shaft. The shaft 22 is fixed by a nut 24. The shaft 22 provided with the spline 23 on the inner side
Is rotatably supported by a bearing 25 provided at the center. 26 is an outer ring of the bearing. 27 is a guide bar provided on the toggle support 5, which supports the crosshead 6 so as to be able to move up and down.

FIG. 7 is a detailed view of FIG. As is apparent from FIGS. 7B and 6, the crosshead 6 has a structure in which the crosshead 6 is pin-coupled to the lower link 4 b of the toggle link mechanism 4 and is moved up and down by being guided by a pair of guide bars 27. .

(Operation) When the servo motor 11 is driven in FIG. 5 and the ball screw shaft 8 is turned through the pulley 12, the belt 13, the pulley 18, the spline (female) 23, and the spline (male) 21, the toggle support 5 Goes up and down. Then
The movable platen 1 is moved up and down via a toggle link mechanism 4 provided between the toggle support 5 and the fixed platen 3 to open and close the mold. At that time, the ball screw shaft 8 moves with the movement of the crosshead 6. Toggle support 5
The allowance for the vertical movement of the ball screw shaft 8 due to the difference in the amount of vertical movement between the servomotor 1 and the crosshead 6 is absorbed by the spline (female) 23 supported by the bearing 25.
1, The positions of the belt 13 and the pulley 18 may be fixed.

(Description of the Present Invention) An ejector device of a vertical electric injection molding machine having an ejector device according to the present invention will be described with reference to FIGS. 1 is a partially longitudinal front view of an ejector device according to the present invention, FIG. 2 is a top view of FIG. 1, FIG. 3 is a view taken in the direction of arrow B in FIG. 2, and FIG.
It is an arrow view. In FIG. 1, reference numeral 36 denotes a bearing holder attached to the movable platen 1 via a bracket 50. Reference numeral 31 denotes a servo motor as a drive source of the ejector rod 43, which is supported by a bearing holder.
The ball screw shaft 32 (FIG. 4) attached to the servomotor 31 is rotated by the servomotor 31. 33
Is a ball nut screwed into the ball screw shaft 32.
Reference numeral 34 denotes a moving member (hereinafter, a ball nut holder) that supports the ball nut 33, and is movable in the direction of arrow a in FIG. 1 while being guided by a guide post 37 provided on a bearing holder 36. The ball screw shaft 32 is a bearing 35
(FIG. 4). Bearing 35
Are supported in the bearing holder 36.

Reference numeral 38 denotes a link attached downward to both ends of the ball nut holder 34.
9 is pin-connected, and a link 40 is pin-connected to the tip of the link 39. The link 40 is connected to a shaft 42 by a pin 41, and an ejector rod 43 is connected to a tip (lower end) of the shaft 42. Reference numeral 44 denotes a guide plate that guides the shaft 42 in the vertical direction, and is mounted on the movable platen 1. Reference numeral 45 denotes a link mechanism support mounted on the movable platen 1, and supports an intermediate position of the link 39 with a pin 45a. 46 is a servo motor control driver.

The ejector rod 43 having the above configuration
Works as follows. (Operation of Ejector) The following operation is performed in response to a command from the control driver 46. With the rotation of the servo motor 31,
By turning the ball screw shaft 32, the ball nut 33
Is converted into a linear motion in the vertical direction. As the servomotor 31 rotates forward and backward, the ball nut holder 34 guided by the guide post 37 moves vertically (arrow a) as shown in FIG. . The operation is transmitted to the link 39 via the link 38 connected to the ball nut holder 34, the link 39, and then transmitted to the shaft 42 by the link 40. Therefore, the ejector rod 43 attached to the shaft 42 with the screw 47 moves up and down (arrow b) as shown in the figure to operate the ejector plate 48.

With the above configuration, the two ejector rods 43, 43 can be arranged on both sides of the screw assembly 49, and the operation of the two ejector rods 43 is to simultaneously operate two links with one drive source. As a result, the ejector plates 48 are operated in perfect synchronism, and the ejector plates 48 are evenly pressed and operated. This tuning operation is performed by the ejector plate 48.
At the same time, the two ejector rods 43 need to be aligned so that the tip positions of the two ejector rods 43 are aligned.
The connection of the third shaft 42 to the shaft 42 is of a screw-in type using a screw 47, whereby the tip positions of the two ejector rods 43 can be adjusted.

In the above description, the servo motor 31 has been described as a drive source. However, any drive that operates the ejector rod 43 via a link mechanism may be used. For example, a hydraulic cylinder may be used as a drive source. Further, a screw jack or a rack-pinion method is also possible. Also, the case where the number of ejector rods is two has been described, but three or more ejector rods may be used. In this case, the number of links may be increased according to the number of ejector rods.

[0016]

According to the present invention, the linear motion of the drive source is controlled by a plurality of ejector rods 43 via the links 38, 39 and 40.
Transmitted simultaneously. Further, since the ejector rod 43 is connected to the shaft 42 by the screw 47, the tips of the plurality of ejector rods 43 can be adjusted. With these configurations,
The plurality of ejector rods 43 move in synchronization with each other, thereby preventing a non-synchronization failure as in the conventional hydraulic type.

[Brief description of the drawings]

FIG. 1 shows a main part of a vertical injection molding apparatus provided with an ejector device of the present invention.

FIG. 2 is a top view of FIG. 1;

FIG. 3 is a view taken in the direction of arrow B in FIG. 2;

FIG. 4 is a view taken in the direction of the arrow A in FIG. 1;

5A and 5B are schematic diagrams of a vertical injection molding machine to which the present invention is applied, wherein FIG. 5A shows a state when the mold is opened, and FIG. 5B shows a state when the mold is fully closed.

FIG. 6 is a detailed view of an upper portion and a lower portion of the ball screw shaft of FIG. 5;

FIG. 7 is a more detailed enlarged view of the same portion as FIG. 6, and FIG.
Is a longitudinal sectional view, and (b) is a sectional view taken along arrow A of (a).

[Explanation of symbols]

Reference Signs List 1 movable platen 2 tie bar 3 fixed platen 4 toggle link mechanism 4a upper link 4b lower link 4c pin 5 toggle support 6 crosshead 6a operating link 7 ball nut 8 ball screw shaft 10 frame 11 servo motor 12 pulley 13 belt 14 injection device 15 nozzle Part 16 Base 17 Support part 18 Pulley 19 Bearing 20 Nut 21 Spline
(Male) 22 axis (with male spline) 23 Spline (Female) 24 Nut 25 Bearing 26 Outer ring of bearing 27 Guide bar 31 Servo motor 32 Ball screw shaft 33 Ball nut 34 Ball nut holder 35 Bearing 36 Bearing holder 37 Guide post 38, 39, 40 link 41 pin 42 axis 43 ejector rod 44 guide plate 45 link mechanism support 45a pin 46 driver 47 screw 48 ejector plate 49 screw assembly

Claims (4)

[Claims] An ejector device for an electric vertical injection molding machine, wherein a plurality of ejector rods are operated by a set of driving devices via a link mechanism so as to operate up and down linearly. Ejector device for injection molding machine. 2. The link (38) wherein a plurality of link mechanisms are attached to the moving member (34), wherein the driving device comprises a driving means for performing a rectilinear motion, and a moving member attached to the driving means.
And a link (39) pivotally supported by a pin (45a) on a link mechanism support (45) mounted on the link (38) and mounted on the movable platen (1), and a pin on the end of the link (39). Linked link (40) and movable platen pin-connected to link (40)
The ejector device for an electric vertical injection molding machine according to claim 1, characterized in that the ejector device comprises a shaft (42) which moves up and down while being guided by a guide plate (44) supported thereon. . 3. An electric motor according to claim 2, wherein the ejector rods (43) are screwed to a shaft (42) for supporting the ejector rods (43) so as to align the ends thereof. Ejector for vertical injection molding machine. 4. The driving means includes a servo motor (31), a ball screw shaft (32) attached to the servo motor (31), and a ball nut (33) screwed into the ball screw shaft (32). The ejector device for an electric vertical injection molding machine according to claim 2, characterized in that: