JP3219143B2 - Ejector device for electric injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, in an injection molding machine, a resin heated and melted in a heating cylinder is filled at a high pressure into a cavity space of a mold apparatus, and cooled and solidified in the cavity space. Thus, a molded article is formed. To this end, the mold apparatus is composed of a fixed mold and a movable mold, and the movable mold is moved forward and backward by a toggle mechanism, and is brought into and out of contact with the fixed mold to close, close, and open the mold. Can be done. In opening the mold, the movable mold is retracted while the molded article remains in the movable mold. Subsequently, the mold is released by the ejector device, the ejector pins are advanced, and the molded article is moved. It is designed to protrude from the mold.

For this purpose, a front end of the ejector pin is disposed facing the cavity space, and a rear end of the ejector pin is fixed to an ejector plate. The rear end of the ejector plate is connected to an ejector pin feeder via an ejector rod. Then, by operating the ejector pin feeder and advancing the ejector plate via the ejector rod, the ejector pin fixed to the ejector plate is advanced and the molded product is ejected.

By the way, in an electric injection molding machine,
Usually, the ejector pin feeder is operated by an electric motor. FIG. 2 is a front view of a conventional single-shaft ejector device, and FIG. 3 is a side view of a conventional single-shaft ejector device. In the figure, reference numeral 11 denotes a movable platen, and a movable mold (not shown) is attached to a front end (right end in FIG. 2) of the movable platen 11. The movable platen 11 is moved by a toggle mechanism 14 along a tie bar 12 provided between a fixed platen (not shown) and a toggle support.

The rear end of the movable platen 11 (FIG. 2)
(The left end of the figure), an ejector pin feeder 16 is provided. In the ejector pin feeder 16,
A front end of a guide post 18 is fixed to the movable platen 11, and a support 19 is fixed to a rear end of the guide post 18. The support 19 rotatably supports a ball screw nut 22 via a bearing 20.

[0006] The ball screw nut 22 is screwed with the ball screw shaft 24 on the inner periphery, a crosshead 25 is fixed to the front end of the ball screw shaft 24, and further to the front end of the crosshead 25. The ejector rod 27 is fixed. Therefore, by rotating the ball screw nut 22, the ball screw shaft 24 can be moved forward and backward in the direction of arrow A, and the ejector rod 27 can be moved forward and backward.

The ejector pin feeder 16 is operated by a servomotor 28, and a belt transmission mechanism 31 is disposed between the servomotor 28 and the ball screw nut 22. The belt transmission mechanism 31
Pulley 3 disposed on the output shaft of the servo motor 28
2, a pulley 33 disposed at the rear end of the ball screw nut 22, and a timing belt 34 as a transmission means stretched between the pulleys 32, 33.

Therefore, when the servo motor 28 is driven, the rotation of the servo motor 28 is transmitted to the ball screw nut 22 via the belt transmission mechanism 31. Then, the rotational motion is converted into a linear motion by the ball screw nut 22 and the ball screw shaft 24, and an ejector pin (not shown) is moved forward and backward. Next, a two-axis ejector device will be described.

FIG. 4 is a front view of a conventional two-axis type ejector device, and FIG. 5 is a side view of a conventional two-axis type ejector device. In the figure, reference numeral 11 denotes a movable platen, and a movable mold (not shown) is attached to a front end (right end in FIG. 4) of the movable platen 11. The movable platen 11
Is moved by a toggle mechanism 14 along a tie bar 12 provided between a fixed platen (not shown) and a toggle support.

The rear end of the movable platen 11 (FIG. 4)
(The left end of the figure), an ejector pin feeder 16 is provided. In the ejector pin feeder 16,
The front end of the guide post 18 is fixed to the movable platen 11, and the crosshead 41 is fixed to the rear end of the guide post 18. Then, a ball screw nut 42 is fixed to the crosshead 41.

Further, the ball screw nut 42 is screwed with a ball screw shaft 43 on the inner periphery, and the ball screw shaft 43 is rotatably supported at a front end by a bearing (not shown). And the crosshead 4
An ejector rod 27 is fixed to the front end of the device 1. Therefore, by rotating the ball screw shaft 43, the crosshead 41 can be moved forward and backward (moved in the left-right direction in FIG. 4), and the ejector rod 27 can be moved forward and backward.

The ejector pin feeder 16 is operated by a servomotor 28, and a belt transmission mechanism 46 is disposed between the servomotor 28 and the ball screw shaft 43. The belt transmission mechanism 46 includes a pulley 32 disposed on an output shaft of the servomotor 28 and a plurality of pulleys 3 disposed on a front end of the ball screw shaft 43.
3, and a timing belt 34 as transmission means stretched between the pulleys 32 and 33.

Accordingly, when the servo motor 28 is driven, the rotation of the servo motor 28 is transmitted to the ball screw shaft 43 via the belt transmission mechanism 46. Then, the rotational motion is converted into a linear motion by the ball screw shaft 43 and the ball screw nut 42, and an ejector pin (not shown) is moved forward and backward.

[0014]

However, in the conventional ejector device, when the ejector device is to be assembled to the movable platen 11, the ejector pin feeder 16 and the servomotor 28 are attached to the movable platen 11, respectively. Further, the timing belt 34
Work is troublesome because it is necessary to extend

In addition, it is not possible to test run or adjust the ejector device before assembling it to the movable platen 11. Further, in the two-axis ejector device shown in FIGS. 4 and 5, the crosshead 41 and the movable platen 1
The timing belt 34 cannot be easily replaced because the timing belt 34 is disposed between the timing belt 34 and the timing belt 34.

The present invention solves the above-mentioned problems of the conventional ejector device, and makes it easy to assemble the ejector device and replace the transmission means, and to perform trial operation or adjustment of the ejector device before assembling. It is an object of the present invention to provide an ejector device of an electric injection molding machine that can perform the operation.

[0017]

For this purpose, in the ejector device of the electric injection molding machine according to the present invention, a mounting plate detachably mounted on a back surface of a movable platen via a guide bar, and the guide bar. A crosshead that is guided and reciprocated, an ejector rod attached to the crosshead, a ball screw shaft rotatably supported on the mounting plate, and a ball screw nut fixed to the crosshead. A ball screw; a drive motor attached to the mounting plate; and a transmission means for transmitting rotation of the drive motor to the ball screw shaft.

In another aspect of the present invention, the ball screw shaft is detachably mounted on the mounting plate. The ball screw nut is detachably mounted on the crosshead. In still another aspect of the present invention, the drive motor is movably mounted on a mounting plate. In still another aspect of the present invention, the transmission means is disposed outside the mounting plate.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 6 is a schematic diagram of an electric injection molding machine according to an embodiment of the present invention.
In the figure, 111 is the injection device, 112 is the injection device 1
A mold clamping device 13 disposed opposite to 11, a molding machine frame 13 that supports the injection device 111 and the mold clamping device 112, and a 114 that is supported by the molding machine frame 13 and supports the injection device 111. An injection device frame 131 is a guide disposed along the longitudinal direction of the injection device frame 114, and 143 is a mold device including a fixed mold 44 and a movable mold 45.

The ball screw shaft 21 is rotatably supported by the injection device frame 114, and one end of the ball screw shaft 21 is connected to the servo motor 1 for the injection device 111.
22. Further, the ball screw shaft 21 and the ball screw nut 23 are screwed together to form a ball screw 84, and the ball screw nut 23 and the injection device 111 are formed.
Are connected via a spring 124 and a bracket 125. Therefore, when the servo motor 122 is rotated in the forward and reverse directions, the rotational motion of the servo motor 122 is converted into a linear motion by the ball screw 84,
The linear motion is transmitted to the bracket 125. And
The bracket 125 is moved along the guide 131 by an arrow x.
The injection device 111 is moved forward and backward.

A heating cylinder 15 is fixed to the bracket 125 toward the front (to the left in the drawing), and an injection nozzle 116 is provided at the front end (to the left in the drawing) of the heating cylinder 15. A hopper 17 is disposed on the heating cylinder 15, and a screw 26 is disposed inside the heating cylinder 15 so as to be able to advance and retreat and rotate freely, and a rear end (right end in the figure) of the screw 26 is a support member. 132 is rotatably supported.

The first servo motor 1
The rotation generated by driving the first servomotor 133 is transmitted to the screw 26 via the timing belt 134. In the injection device frame 114, a ball screw shaft 35 is rotatably supported in parallel with the screw 26, and the ball screw shaft 35 and the second servomotor 36 are connected via a timing belt 37. . The ball screw shaft 35 is screwed with a ball screw nut 141 fixed to the injection pusher plate 132b to form a ball screw 85. The injection pusher plate 132b is fixed to the support member 132 via a load cell 132a. Accordingly, the rotation generated by driving the second servomotor 36 is transmitted to the ball screw shaft 35 via the timing belt 37, and the rotation is generated.
5 is rotated. Thereby, the ball screw nut 1
41 is moved in the direction of arrow B.

Next, the operation of the injection device 111 having the above configuration will be described. First, in the measuring step, the first servomotor 133 is driven, the screw 26 is rotated via the timing belt 134, and the screw 26 is retracted to the predetermined position (moved to the right in the drawing). At this time, the resin supplied from the hopper 17 is heated and melted in the heating cylinder 15, and is stored (accumulated) in front of the screw 26 as the screw 26 retreats.

Next, in the injection step, the injection nozzle 1
16 is pressed against the fixed mold 44 and the second servomotor 36 is pressed.
To rotate the ball screw shaft 35 via the timing belt 37. At this time, the support member 132 is moved with the rotation of the ball screw shaft 35 to move the screw 26 forward (moving to the left in the drawing), so that the resin accumulated in front of the screw 26 is injected. Injected from the nozzle 116, the fixed mold 44 and the movable mold 45
Is filled in the cavity space 47 formed between the two.

Next, the mold clamping device 112 will be described. The mold clamping device 112 includes a fixed platen 51, a toggle support 52, and the fixed platen 51 and the toggle support 5.
2, a movable platen 54 disposed opposite to the fixed platen 51, and movable along the tie bar 53 so as to be able to advance and retreat (move in the left-right direction in the drawing). A toggle mechanism 56 is provided between the movable platen 54 and the toggle support 52. The fixed platen 51 and the movable platen 5
4, the fixed mold 44 and the movable mold 45 are attached to face each other.

The toggle mechanism 56 moves the movable platen 54 along the tie bar 53 by moving the crosshead 58 between the toggle support 52 side and the movable platen 54 side by means of a mold clamping servomotor (not shown). The movable mold 45 is moved forward and backward, and the movable mold 45 is moved toward and away from the fixed mold 44 to close, close, and open the mold.

To this end, the toggle mechanism 56 includes a toggle lever 61 swingably supported by the crosshead 58, a toggle lever 62 swingably supported by the toggle support 52, Platen 54
, And the link between the toggle levers 61 and 62 and between the toggle lever 62 and the toggle arm 63 are link-coupled to each other.

A ball screw shaft 64 is rotatably supported by the toggle support 52, and the ball screw shaft 64 and a ball screw nut 65 fixed to the crosshead 58 are screwed together. 86 are formed. Then, in order to rotate the ball screw shaft 64, the mold clamping servomotor is attached to a side surface of the toggle support 52.

Therefore, when the mold clamping servomotor is driven, the rotational motion of the mold clamping servomotor is converted into linear motion by the ball screw 86, and the linear motion is transmitted to the crosshead 58, and 58 is arrow C
Moved in the direction. That is, the crosshead 5
8 is advanced (moved rightward in the figure), the toggle mechanism 56 is extended, the movable platen 54 is advanced, the mold is closed and the mold is closed, and the crosshead 58 is retracted.
When the movable platen 54 is moved (to the left in the drawing), the toggle mechanism 56 is bent and the movable platen 54 is retracted, and the mold is opened.

On the back of the movable platen 54,
A two-axis type ejector device 71 is provided. The ejector device 71 extends through the movable mold 45 and has a front end (right end in the figure) facing the cavity space 47 (not shown). , An ejector rod (not shown) arranged behind (left side in the figure), a ball screw shaft 72 arranged behind the ejector rod, and rotated by a servomotor for projection (not shown) as a drive motor; It has a ball screw nut 73 screwed with the ball screw shaft 72, and the ball screw 87 is formed by the ball screw shaft 72 and the ball screw nut 73.

Accordingly, when the servo motor for projecting is driven, the rotational motion of the servo motor for projecting is converted into linear motion by the ball screw 87, and the linear motion is transmitted to the ejector rod, and the ejector rod and the ejector are moved. The pin is moved back and forth in the direction of arrow D.
Next, the ejector device 71 will be described.

FIG. 1 is a side view of the ejector device of the electric injection molding machine according to the embodiment of the present invention, FIG. 7 is a rear view of the ejector device of the electric injection molding machine according to the embodiment of the present invention, and FIG. FIG. 9 is a plan view of an ejector device assembly according to the embodiment of the present invention. FIG. 9 is a side view of the ejector device assembly according to the embodiment of the present invention.
0 is a diagram illustrating an example of mounting a ball screw according to an embodiment of the present invention, and FIG. 11 is a detailed view illustrating an example of mounting a ball screw according to an embodiment of the present invention.

In the figure, 53 is a tie bar, 54 is a movable platen, 71 is an ejector device which is detachably mounted on the movable platen 54, and the ejector device 71 is a back surface of the movable platen 54, that is, , A mounting plate 92 mounted on the back side of the punch surface by bolts b1 to b4, and 2 mounted on the mounting plate 92.
A set of ball screws 87, a servomotor 95 for projection provided on a side edge of the mounting plate 92 on the non-operation side, a transmission unit 96 for transmitting rotation of the servomotor 95 to the ball screw 87, the mounting plate A crosshead 93 disposed parallel to and movably with the 92; a plurality of ejector rods 9 attached to the crosshead 93;
4, and an ejector pin (not shown) attached to the front end of the ejector rod 94. The mounting plate 92 has a mounting hole 108 for allowing the bolts b1 to b4 to pass therethrough.

The mounting plate 92 has two through holes 101 for mounting the ball screws 87. Then, a part is fitted into the through hole 101 (can).
And the flange 115 is fixed by bolts b5.
2, the ball screw shaft 72 is rotatably supported.
The ball screw shaft 72 includes a screw portion 72a for screwing with a ball screw nut 73 fixed to the crosshead 93 by a bolt b7, and a shaft portion 72b for being supported by a bearing 102.
The rear end of the shaft portion 72b (FIG. 11)
(The right end in the drawing), the pulley 103 is fixed. An idle roller 105 is rotatably disposed between the ball screws 87 on the mounting plate 92,
A pulley 109 is fixed to an output shaft 95a of the servo motor 95. A timing belt 110 as a transmission means is stretched between the pulley 103, the idle roller 105, and the pulley 109. The pulley 1
The transmission unit 96 is constituted by the transmission belts 03 and 109, the idle roller 105 and the timing belt 110.

The servo motor 95 is provided with a bolt b
It is fixed to the mounting plate 92 by 11 to b14.
Adjustment screws b21 and b22 are provided to adjust the position of the servo motor 95 and adjust the tension of the timing belt 110. Further, a guide bar 211 is formed so as to protrude from the mounting plate 92, and extends toward the movable platen 54 and extends through the crosshead 93. Therefore,
When the servo motor 95 is driven, the servo motor 9
5 is converted into a linear motion by the ball screw 87, and the linear motion is transmitted to the crosshead 93, and the crosshead 93 is moved back and forth along the guide bar 211. The guide bar 211 is provided with a ball screw shaft 72.
Is rotated, the cross head 93 is prevented from rotating. The front end of the guide bar 211 (FIG. 1)
The left end of the movable platen 54 is fitted into a support hole 54a formed on the back side of the punch surface of the movable platen 54, and the cross head 93 is positioned by the support hole 54a. Therefore, since the guide bar 211 is supported at both ends by the mounting plate 92 and the movable platen 54, the strength can be increased.

As described above, when assembling the ejector device 71 to the movable platen 54, the ball screw 87 and the servomotor 95 are attached to the mounting plate 92 in advance.
After assembling and stretching the timing belt 110,
Since only the mounting plate 92 needs to be mounted on the movable platen 54, the mounting can be easily performed. Also,
Before assembling the ejector device 71 to the movable platen 54, the ball screw 87, the servomotor 95, and the like are assembled to the mounting plate 92, and the ejector device 71 is tested or adjusted with the timing belt 110 stretched. Can be.

Further, since the timing belt 110 is provided outside the mounting plate 92, the timing belt 110 can be easily replaced. When replacing the ball screw shaft 72, the adjusting screws b21, b2
2, the timing belt 110 is loosened, and the bolt b
By loosening 5, b7, the ball screw 87 can be removed from the mounting plate 92 and the crosshead 93. In this case, since the pulley 103 is attached to the rear end of the ball screw shaft 72, it is easy to replace the pulley with another pulley and change the reduction ratio.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0039]

As described in detail above, according to the present invention, in the ejector device of the electric injection molding machine,
A mounting plate detachably attached to the rear surface of the movable platen via a guide bar, a crosshead guided by the guide bar to move forward and backward, an ejector rod attached to the crosshead, And a ball screw formed of a ball screw nut fixed to the crosshead, a drive motor attached to the mounting plate, and a rotation of the drive motor attached to the ball screw shaft. Transmission means for transmitting.

In this case, when assembling the ejector device to the movable platen, it is only necessary to assemble a ball screw, a drive motor and the like in advance to the mounting plate, arrange the transmission means, and then mount the mounting plate to the movable platen. Therefore, assembly can be performed easily. Before assembling the ejector device to the movable platen,
A ball screw, a drive motor, and the like are assembled to the mounting plate, and a trial operation or adjustment of the ejector device can be performed with the transmission means provided.

Further, since both ends of the guide bar are supported by the mounting plate and the movable platen, the strength of the guide bar can be increased. In another aspect of the present invention, the ball screw shaft is detachably mounted on the mounting plate. The ball screw nut is detachably mounted on the crosshead. In this case, the ball screw can be easily replaced.

[0042] In another aspect of the present invention, the drive motor is movably mounted on a mounting plate. In this case, the transmission means can be adjusted by changing the position of the drive motor. In still another aspect of the present invention, the transmission means is disposed outside the mounting plate. In this case, since the transmission means is disposed outside the mounting plate,
The transmission means can be easily replaced.

[Brief description of the drawings]

FIG. 1 is a side view of an ejector device of an electric injection molding machine according to an embodiment of the present invention.

FIG. 2 is a front view of a conventional one-axis type ejector device.

FIG. 3 is a side view of a conventional one-axis type ejector device.

FIG. 4 is a front view of a conventional two-axis type ejector device.

FIG. 5 is a side view of a conventional two-axis type ejector device.

FIG. 6 is a schematic view of an electric injection molding machine according to an embodiment of the present invention.

FIG. 7 is a rear view of the ejector device of the electric injection molding machine according to the embodiment of the present invention.

FIG. 8 is a plan view of the ejector device assembly according to the embodiment of the present invention.

FIG. 9 is a side view of the ejector device assembly according to the embodiment of the present invention.

FIG. 10 is a diagram illustrating an example of mounting a ball screw according to the embodiment of the present invention.

FIG. 11 is a detailed view showing an example of mounting a ball screw according to the embodiment of the present invention.

[Explanation of symbols]

 54 Movable platen 71 Ejector device 72 Ball screw shaft 73 Ball screw nut 87 Ball screw 92 Mounting plate 93 Cross head 94 Ejector rod 95 Servo motor 110 Timing belt 211 Guide bar

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (4)

(57) [Claims] 1. A guide bar is provided on the back of a movable platen.
And mounting et a mounting plate detachably via a crosshead which is advanced and retracted while being guided by (b) the guide bar, an ejector rod attached to the (c) the crosshead, (d) the mounting A ball screw composed of a ball screw shaft rotatably supported on the plate and a ball screw nut fixed to the crosshead; (e) a drive motor mounted on the mounting plate; and (f) the drive. And a transmission means for transmitting the rotation of the motor to the ball screw shaft. 2. The ball screw shaft according to claim 1, wherein: (a) the ball screw shaft is removably mounted on the mounting plate; and (b) the ball screw nut is removably mounted on the crosshead. An ejector device for the electric injection molding machine described in the above. 3. The ejector device according to claim 1, wherein the drive motor is movably mounted on a mounting plate. 4. The transmission means is disposed outside a mounting plate.
The ejector of the electric injection molding machine according to claim 1, which is provided.
Data device.