JP4270327B1 - Molding device for injection molding machine - Google Patents

Abstract

[PROBLEMS] To prevent the fixed platen from tilting forward due to the nozzle touch operation, to suppress the asymmetrical deformation of the fixed platen when the mold is clamped, and to eliminate the need for maintenance and excellent durability. A mold clamping device for an injection molding machine is provided.
A fixed plate 2 standing on a machine body 7 and a nozzle 31 is inserted into a fixed mold K1 attached to the fixed plate 2 so as to advance and retreat toward the center of one surface of the fixed plate 2. The nozzle touch mechanism for pressing, the end plate 4 connected to the other surface side of the fixed platen 2 via the diver 5, and the molds K 1 and K 2 are moved forward and backward in parallel to the diver 5 and fixed to the fixed platen 2. In a mold clamping device 1 of an injection molding machine provided with a movable plate 2 for clamping, the upper end is fixed to both sides of the fixed platen 2 at a substantially central position in the vertical direction of the side surface of the fixed platen 2 and the lower end is a machine body 7. A fixed frame 11 formed in a frame shape is provided to leave the outer edge portion.
[Selection] Figure 1

Description

  The present invention relates to a mold clamping device of an injection molding machine including a movable plate that moves in a forward / backward direction with respect to a fixed platen.

  Conventionally, an injection molding method has been used because it can efficiently produce a large number of molded products with complicated shapes. Generally, a horizontal injection molding machine moves a movable plate forward and backward with respect to a fixed plate by a mold clamping mechanism. A mold clamping device adapted to perform opening / closing and mold clamping operations is provided.

  The mold clamping device is fixed to the machine body and fixes the fixed mold, and is disposed at a position facing the fixed disk and moves in the forward / backward direction with respect to the fixed disk. A movable plate that engages with a fixed mold and clamps the mold, an end plate provided on the retracted side of the movable plate in the advancing / retreating direction, and one end fixed to the fixed plate while supporting the movable plate so that the movable plate can move forward and backward Has a structure including a diver fixed to the end plate and a toggle mechanism for guiding the diver to move the movable plate in the forward and backward direction with respect to the fixed plate.

During the molding operation by the mold clamping device of such an injection molding machine, when the nozzle driving device approaches the fixed platen, a nozzle touch operation is performed in which the nozzle is pressed against the fixed mold of the fixed platen with a predetermined force.
At this time, for example, as shown in FIG. 8, the fixed platen 72 is tilted to the front side of the nozzle 73 by the pressing force of the nozzle 73 against the fixed side die 71, so that the fixed platen 72 and the movable platen 74 are attached. There was a problem that the parallelism with the movable mold 75 could not be maintained, and the straightness of the mold opening and closing was impaired.
When the straightness is thus lost, guide pins (not shown) provided on the mold surface of the movable mold 75 are connected to bushes (not shown) formed on the mold surface of the fixed mold 71. It becomes difficult to insert smoothly, and when the opening and closing of the mold is repeated in this state, the wear of the bushes and the like progresses. As a result, the straightness of both molds 71 and 75 itself is further impaired, and the internal parts of the mold clamping device 76 Could lead to damage.
Further, since the lower part of the fixed platen 72 is fixed on the machine body 77, the upper part of the fixed platen 72 is not fixed, so that the deformation of the fixed platen 72 is asymmetric in the vertical direction during mold clamping. As a result, there is a problem that uniform mold clamping force does not act and molding defects occur.

Therefore, in order to cope with this problem, for example, Patent Document 1 proposes a stationary platen that is rotatably supported by a support leg from one side through one support shaft. The axis of the support shaft of this injection molding machine intersects the center axis of the fixed platen, and the nozzle touch operation is performed by aligning the axis of the nozzle with the central axis of the fixed platen, so that the fixed platen moves to the front side of the nozzle. Inclination can be prevented.
JP 2001-239561 A

By the way, the above injection molding machine has the following problems.
That is, when the nozzle touch operation is continuously performed, the operation of slightly rotating the support shaft is repeated. As a result, the support shaft makes a minute reciprocating slide with respect to the support leg, and thus there is a problem that fretting friction is likely to occur between the two.
In addition, for example, even when a rolling bearing is disposed on the support shaft, the amount of rotation of the rolling elements in the bearing is so small that the lubrication condition is likely to deteriorate, and not only maintenance and time are required, There was a risk of breakage early.
Furthermore, when a molded product or runner take-out robot is attached to the upper part of the fixed platen, there is a risk that the fixed platen will rotate around the support shaft due to the movement, and an accurate mold clamping operation cannot be performed. there were.

  The present invention has been made in view of such a problem, and prevents a phenomenon in which the fixed platen tilts forward by a nozzle touch operation, and causes asymmetrical deformation of the fixed platen when performing mold clamping. It is another object of the present invention to provide a mold clamping device for an injection molding machine that suppresses the above-described problem and that does not require maintenance and has excellent durability.

In order to solve the above problems, the present invention proposes the following means.
That is, a mold clamping device of an injection molding machine according to the present invention comprises a stationary platen standing on a machine body,
A nozzle touch mechanism that advances and retreats toward the center of one surface of the fixed plate and presses a nozzle against a mold attached to the fixed plate, and a plurality of other surfaces on the other surface side opposite to the one surface of the fixed plate An end plate connected via a diver, and a movable plate provided between the fixed platen and the end plate, moving forward and backward along the diver and clamping a mold with the fixed platen, and In a mold clamping device of an injection molding machine, a frame shape is formed by four members, a first fixing bar, a second fixing bar, a fixing plate support bar, and a mounting bar, on both sides in the pressing direction of the nozzle touch mechanism of the fixing plate. a is integrally formed the void portion is a through portion forming a trapezoidal shape, the stationary platen support bars connecting the upper end side ends of the first fixing bar and the second fixing bar which extends vertically in the horizontal direction is the Fixed platen A fixing frame that is fixed at a substantially central position in the vertical direction of the surface and that connects the lower end of the first fixing bar and the second fixing bar to the machine body; and the nozzle touch mechanism includes the nozzle touch mechanism When the first fixed bar and the second fixed bar of the fixed frame are deformed in the pressing direction of the nozzle touch mechanism when pressed against the fixed plate, the fixed plate is displaced in parallel to the diver. It is characterized by.

According to the mold clamping device of the injection molding machine having such a feature, when the pressing force of the nozzle touch mechanism reaches the mold, the fixed frame formed in a frame shape is deformed in the nozzle pressing direction. As a result, the stationary platen supported by the stationary frame can be displaced in parallel along the diver, so that it is possible to suppress the tilting of the stationary platen.
Accordingly, since the deformation of the stationary platen is symmetrical in the vertical direction during mold clamping, a uniform mold clamping force can be applied, and the molding accuracy can be improved.
Further, since the fixed platen and the fixed frame are fixed without using a rotating shaft or the like, there is no frictional / sliding portion, and maintenance is facilitated.
Furthermore, since the fixed platen does not rotate inadvertently, the fixed platen is in a stable state even when, for example, a molded product or a runner removal robot is attached to the top of the fixed platen. Therefore, mold clamping can be performed reliably.

  Further, in the mold clamping device of the injection molding machine, the upper end side of the fixed frame is fixed above the substantially central position in the vertical direction instead of the substantially central position in the vertical direction on the side surface of the fixed platen. It is characterized by.

When the pressing force of the nozzle touch mechanism reaches the approximate center of the fixed platen, a moment centering on the fixed position with the machine body acts on the fixed frame that supports the fixed platen, and this fixes the top surface of the machine body. The deformation is caused by being pulled by the frame, and a slight inclination is generated in the fixed platen.
In this respect, if the fixing position of the fixed frame to the stationary platen is above the substantially vertical position in the vertical direction, when the pressing force of the nozzle reaches the substantially central part of the stationary platen, A moment acts around the fixed point with the fixed frame. In other words, the moment acting on the stationary platen and the moment acting on the stationary frame are opposite to each other, so that both moments cancel each other out, thereby reliably preventing tilting of the stationary platen. It becomes possible.

According to the mold clamping device of the injection molding machine of the present invention, when the nozzle is pressed against the mold attached to the fixed platen, the fixed plate is displaced in parallel with the diver when the fixed frame is deformed. The board does not tilt forward. As a result, the fixed mold and the movable mold can be kept parallel, and smooth processing with high molding accuracy can be performed.
In addition, since the fixed platen and the fixed frame are fixed without using a rotating shaft or the like, there is no place to be rubbed and slid, and maintenance can be facilitated and durability can be improved.
Furthermore, since the stationary platen does not rotate carelessly, for example, even when a molded product or a runner take-out robot is attached to the upper part of the stationary platen, the stationary platen is in a stable state. The mold clamping operation can be performed reliably.

Hereinafter, a first embodiment of a mold clamping device of an injection molding machine according to the present invention will be described in detail with reference to FIGS.
1 is a side view showing a schematic configuration of a mold clamping device of an injection molding machine according to a first embodiment of the present invention, FIG. 2 is a front view of the stationary platen of FIG. 1, and FIG. 3 is a pressing force of a nozzle on the stationary platen. FIG. 4 is a diagram for explaining the operation when the fixed platen is clamped.

  As shown in FIG. 1, the mold clamping device 1 has a machine body 7 as a base, a fixed platen 2 on which a fixed mold K1 is fixed on the machine body 7, and the fixed platen 2. The movable-side mold K2 is fixed to one side surface (movable-side mold mounting surface 3a) facing the fixed-side mold K1, and is moved forward and backward (arrows shown in FIG. 1). E-direction, mold clamping opening / closing direction) by moving the movable mold 3 to the stationary mold K1 and clamping the mold, and the movable board 3 in the advancing and retreating direction. A plurality of end plates 4 and a movable plate 3 supported so as to be movable back and forth, one end fixed to the fixed plate 2 and the other end fixed to the end plate 4 (four, only two shown in FIG. 1) The diver 5 and the movable platen 3 are moved in the forward and backward directions with respect to the fixed platen 2 using these divers 5 as a guide. , And a toggle mechanism 6 for performing mold opening and closing, mold clamping operation of the movable side mold K2 (link mechanism) with respect to the fixed side mold K1.

  In the toggle mechanism 6, two toggle links 61 linked to each other are arranged on the upper and lower sides of the mold clamping device 1, and the front end portions of these toggle links 61 are connected to the rear surface 3 b (the movable mold mounting surface 3 a and the movable side mold mounting surface 3 a). The rear end portion is connected to the front surface 4 a of the end plate 4. Then, the crosshead 63 is moved between the movable platen 3 and the end plate 4 via the screw shaft 64 by a driving device such as an electric motor (not shown), thereby via the toggle link 61 supported by the crosshead 63. The movable platen 3 is advanced and retracted along the divers 5, 5,..., And the pair of molds K1 and K2 held by the fixed platen 2 and the movable platen 3 are clamped or opened.

The movable platen 3 has a substantially square surface and a mold clamping direction (arrow E shown in FIG. 1) along a guide rail 8 (guide rail) installed on the machine body 7 parallel to the diver 5 (clamping direction). Direction).
Here, the guide rails 8 are arranged at a predetermined interval (interval larger than the width of the movable platen 3), and the installation range is a range from the end plate 4 to the movable platen 3 in a side view shown in FIG. Yes. A movable plate guide block 9 guided along the guide rail 8 is fixed to the lower end of the movable plate 3 via a support base 9a.

  The end plate 4 has a substantially square plate surface, and an end plate guide block 10 fixed to the bottom of the end plate 4 is guided along the guide rail 8 so that the end plate 4 can advance and retreat in the mold clamping direction (arrow E direction). It is provided as follows.

As shown in FIGS. 1 and 2, the fixed platen 2 has a substantially square plate surface and is arranged in parallel with the movable platen 3 and the end plate 4, and its side surface 2 c is erected on the machine body 7. It is fixedly supported by being attached to the fixed frame 11.
The surface of the fixed platen 2 facing the movable platen 3 is a fixed side die mounting surface 2a to which the fixed side die K1 is attached, and the surface opposite to the fixed side die mounting surface 2a is the center side. The nozzle insertion surface 21b (see FIG. 2) has a nozzle facing surface 2b.

  Further, as shown in FIG. 2, a fixed convex portion 22 to be attached to the fixed frame 11 is formed at a substantially central portion in the vertical direction of both side surfaces 2 c of the fixed platen 2. The fixed convex portion 22 has a shape that is cut out in a substantially L shape downward in a front view shown in FIG. 2, and a surface facing the side of the fixed platen 2 at the cutout portion. Is formed such that two bolt holes 23 are juxtaposed in the horizontal direction. Further, a surface facing the lower side of the notch is a contact surface 24 that contacts the upper end surface 16 a of the fixed frame 11.

  The fixed frame 11 is a frame-like member formed such that a substantially trapezoidal plate-like member is left through the outer edge portion, and as shown in FIG. The portion is a through portion 12. The two bar-shaped portions extending vertically on the fixed frame 11 are defined as a first fixed bar 13 and a second fixed bar 14, and the upper ends of the first fixed bar 13 and the second fixed bar 14 are horizontally aligned. A portion connected in the direction is a fixed plate support bar 16 that fixes the fixed plate 2 via two bolts 15.

  Of the two fixed bars 13, 14, the second fixed bar 14 located on the nozzle facing surface 2b side is inclined so as to protrude from the nozzle facing surface 2b as it goes from the upper end to the lower end. The lower ends of the second fixed bar 14 and the first fixed bar 13 are connected to each other by an attachment bar 17 attached to the machine body 7 via a support base 18. The mounting bar 17 is fixed to the support base 18 and the machine body 7 by bolts 19 at both ends in the left-right direction in FIG.

  Thus, the fixed frame 11 is formed in a frame shape by the four members of the first fixed bar 13, the second fixed bar 14, the fixed plate support bar 16 and the mounting bar 17. The fixed platen 2 is connected to the fixed platen 2 via two bolts 15. At this time, the contact surface 24 of the fixed convex portion 22 of the fixed platen 2 contacts the flat upper end surface 16 a of the fixed platen support bar 16. The fixed platen 2 is firmly fixed and integrated with the fixed frame 11.

  An injection device (not shown) is installed at a position apart from the nozzle facing surface 2b of the stationary platen 2 of the mold clamping device 1 as described above, and the heating cylinder 30 is connected to the nozzle insertion hole 21 of the stationary platen 2. It is arranged on the extension line of the axis. As the injection device is operated by a conventionally known nozzle driving device (not shown), the nozzle 31 provided at the tip of the heating cylinder 30 passes through the nozzle insertion hole 21 and comes into contact with the fixed mold K1. A nozzle touch operation for leaving the stationary mold K1 and escaping from the nozzle insertion hole 21 is performed.

  In the mold clamping device 1 of the injection molding machine having the above-described configuration, at the start of the molding operation, the crosshead 63 of the toggle mechanism 6 is moved to the fixed platen 2 side, and the movable platen 3 moves forward, thereby fixing the mold. The mold clamping operation of the side mold K1 and the movable mold K2 is performed. Then, the injection device is pulled by the nozzle drive device and moved forward on the machine body 7 from its standby position to the mold clamping device 1 side, and the nozzle 31 of the heating cylinder 30 passes through the nozzle insertion hole 21 of the stationary platen 2. Then, the fixed mold K1 is pushed with a predetermined force to perform injection molding.

Here, as shown in FIG. 3, during the nozzle touch operation in which the nozzle 31 is pushed into the fixed mold K1, the moment to tilt the fixed plate 2 in the pushing direction of the nozzle 31 is shown. Acts and no special measures are taken, for example, the fixed platen 72 is inclined as shown in FIG.
In this respect, according to the mold clamping device 1, when the pressing force F1 of the nozzle 31 reaches the fixed mold K2, the first of the fixed frames 11 on both sides of the fixed platen 2 is shown in FIG. The first fixed bar 13 and the second fixed bar 14 are deformed in the pressing direction of the nozzle 31, and the fixed platen 2 is displaced in parallel along the diver 5.
Thereby, since it is possible to prevent the fixed platen 2 from being inclined, the fixed side mold K1 and the movable side mold K2 can be kept parallel, and smooth processing with high molding accuracy can be performed. .

  Further, since either the upper part or the lower part of the fixed platen 2 is not in a fixed state, the force transmitted from the fixed platen 2 to the diver 5 (force applied in the direction of arrow F2 in FIG. 4) is equal in the upper and lower divers 5. Thus, the fixed platen 2 is not subject to asymmetrical deformation in the vertical direction. As a result, as shown in FIG. 4, a uniform mold clamping force F3 can be applied to the fixed side mold K1, so that good molding can be performed.

Further, the fixed platen 2 and the fixed frame 11 are firmly connected by the contact between the two bolts 15, the contact surface 24 of the fixed convex portion 22, and the upper end surface 16 a of the fixed support portion without using a rotating shaft or the like. Since there is no frictional / sliding portion between the fixed platen 2 and the fixed frame 11, durability can be improved and maintenance can be facilitated.
Furthermore, since the fixed platen 2 is fixedly fixed to the fixed frame 11, for example, even if a molded product or a runner take-out robot is attached to the upper portion of the fixed platen 2, the fixed platen 2 is in a stable state. The mold clamping operation can be reliably performed by being held.

  Next, a second embodiment of the mold clamping device of the injection molding machine of the present invention will be described with reference to FIG. The mold clamping device 70 of the second embodiment is substantially the same as the mold clamping device 1 of the first embodiment shown in FIG. 1, but the mold clamping device 1 of the first embodiment is the same. The fixed frame 11 is fixed at a substantially central portion in the vertical direction of the fixed platen 2, but is different in that it is fixed above the central portion in the vertical direction. In FIG. 5, the same components as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  That is, in the mold clamping device 70 of the second embodiment, as shown in FIG. 5, the first fixing bar 13 and the second fixing bar 14 of the fixing frame 11 are formed so as to extend vertically longer than the first embodiment. The fixed platen support bar 16 that connects the upper ends of the first fixed bar 13 and the second fixed bar 14 is located at a position that is approximately h above the vertical center of the side surface of the fixed platen 2. Is fixedly supported.

Here, when the pressing force F1 of the nozzle 31 reaches the fixed mold K1, a moment M1 centered on the fixed position with the machine body 7 acts on the fixed frame 11 that supports the fixed platen 2, thereby causing the machine to move. The upper surface of the body 7 may be slightly deformed by being pulled by the fixed frame, and as a result, the fixed platen 2 may be inclined.
In this respect, in the mold clamping device 70 according to the second embodiment, the fixing frame 11 is fixed at a location h higher than the substantially central position of the side surface 2c of the stationary platen 2 in the vertical direction. When F1 reaches the fixed mold K1, a moment M2 centering on a fixed position with the fixed frame 11 acts on the fixed platen 2 itself.

  That is, as shown in FIG. 5, since the moment M1 acting on the fixed frame 11 and the moment M2 acting on the stationary platen 2 are opposite to each other, the two moments M1 and M2 cancel each other. The deformation of the machine body 7 is suppressed, and the inclination of the stationary platen 2 can be prevented. Thereby, a uniform mold clamping force can be applied, and better molding can be performed.

  As mentioned above, although embodiment of the mold clamping apparatuses 1 and 70 which are this invention was described in detail, unless it deviates from the technical idea of this invention, it is not limited to these, A some design change etc. are also possible. is there.

For example, as a modification of the mold clamping device 1 of the first embodiment, a mold clamping device 80 as shown in FIG. 6 may be used. That is, in the mold clamping device 1 of the first embodiment, the second fixing bar 14 of the fixed frame 11 is arranged so as to protrude from the nozzle facing surface 2b. The second fixed bar 14 has a shape extending linearly in the vertical direction, like the first fixed bar 13.
By adopting such a configuration, it is possible to secure a large occupied area of the penetrating portion 12 on the upper side of the fixed frame 11, so that the fixed frame 11 is easily deformed, and the pressing force of the nozzle 31 is increased by the fixed side mold K1. It is possible to displace the fixed platen 2 in parallel with the diver 5 more easily.

  In the first and second embodiments, the frame-shaped fixed frame 11 is used as a fixed support for the fixed platen 2. However, the present invention is not limited to this, and for example, a modified example As shown in FIG. 7, the fixed platen 2 may be supported by only a plurality of (two in FIG. 7) fixed bars 50 extending in the vertical direction. Also by this, each fixed bar 50 is deformed, whereby the fixed platen 2 can be displaced in parallel along the diver 5 to prevent the fixed platen 2 from being inclined.

It is a side view showing a schematic structure of a mold clamping device of an injection molding machine concerning a 1st embodiment of the present invention. It is a front view of the stationary platen of FIG. It is a figure explaining an effect | action when the pressing force of a nozzle reaches a fixed platen. It is a figure explaining an effect | action when mold-clamping is performed to a stationary platen. It is a side view which shows the principal part of the mold clamping apparatus of the injection molding machine which concerns on 2nd Embodiment of this invention. It is a side view which shows the principal part of the mold clamping apparatus of the injection molding machine which concerns on a modification. It is a side view which shows the principal part of the mold clamping apparatus of the injection molding machine of a modification. It is a side view which shows the principal part of the conventional mold clamping apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Clamping device 2 Fixed platen 2b Nozzle facing surface 3 Movable platen 3a Movable side mold mounting surface 4 End plate 5 Diver 7 Machine body 11 Fixed frame 12 Through part 13 First fixed bar 14 Second fixed bar 16 Fixed plate support bar 16a Upper end surface 22 Fixed convex part 24 Contact surface 31 Nozzle 50 Fixing bar 61 Toggle link 62 Toggle bracket 70 Clamping device 80 Clamping device K1 Fixed side mold (mold)
K2 movable mold

Claims (2)

A stationary platen standing on the machine body;
A nozzle touch mechanism that advances and retreats toward the center of the one surface side of the fixed platen and presses the nozzle against a mold attached to the fixed platen;
An end plate connected via a plurality of divers to the other side of the fixed plate located on the opposite side of the one side;
In a mold clamping device of an injection molding machine provided with a movable plate provided between the fixed plate and the end plate, moving forward and backward along the diver and clamping a mold with the fixed plate,
Wherein the pressing both sides of the fixed platen of the nozzle touch mechanism, first fixing bar, the second fixed bar, fixed platen support bar and its void portions trapezoidal is integrally formed by four members in a frame-shaped mounting bar The fixed plate support bar that connects the upper end sides of the first fixed bar and the second fixed bar extending in the horizontal direction in the horizontal direction is fixed at a substantially vertical center position on the side surface of the fixed plate. The fixing bar connecting the lower ends of the first fixing bar and the second fixing bar is fixed to the machine body,
When the nozzle touch mechanism is pressed against the fixed plate, the first fixed bar and the second fixed bar of the fixed frame are deformed in the pressing direction of the nozzle touch mechanism, so that the fixed plate becomes the diver. A mold clamping device for an injection molding machine, wherein the mold clamping device is displaced parallel to the mold.   2. The injection molding machine according to claim 1, wherein an upper end side of the fixed frame is fixed above a substantially central position in the vertical direction instead of a substantially central position in a vertical direction on a side surface of the fixed platen. Mold clamping device.

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