JP4451382B2 - Molding device for injection molding machine - Google Patents

Description

  The present invention relates to a mold clamping device of an injection molding machine that performs a mold opening / closing operation by a toggle mechanism.

  An injection molding machine that performs a mold opening / closing operation by a toggle mechanism needs to adjust the position of the pressure receiving plate in the mold opening / closing direction in accordance with the replacement of the mold. Therefore, on the pressure receiving plate side, a tie bar having a screw engraved on the outer periphery, a small gear that is attached to the pressure receiving plate and screwed to the screw of the tie bar, a large gear that is engaged with each of the small gears, and a large gear There is provided a mold thickness adjusting mechanism including a driving mechanism for rotating the mold. Among them, there are various mechanisms for holding the large gear on the pressure receiving plate.

  In Patent Document 1, the large gear is pivotally supported on the pressure receiving plate coaxially with the ball screw shaft for mold clamping, so that the structure of the apparatus is complicated and a large-diameter bearing needs to be used. In Patent Document 2, the outer periphery of the flange and the large gear are brought into surface contact with each other, and both slide when the large gear rotates. However, there is a problem that a motor that rotationally drives the large gear requires a large torque. Furthermore, in Patent Document 3, the large gear is supported by four support rollers. However, since the large gear is subjected to its own weight, the four support rollers and the inner periphery of the large gear are in uniform contact with each other. Was difficult. As a result, there has been a problem that the intervals between the large gear and the small gear screwed to the tie bar are not uniform.

  The difference in backlash between the large gear and the small gear causes a difference in backlash. When the large gear is rotated during mold thickness adjustment, the pressure receiving plate starts moving from the portion where the backlash is small, and the pressure receiving plate is moved smoothly. In addition to this, there is a problem in that the moving distance of each part of the pressure receiving plate is different. If the pressure receiving plate is inclined with respect to the bed, the parallel accuracy of the movable mold and the fixed mold cannot be obtained at the time of molding, which causes molding defects.

Japanese Patent Laying-Open No. 2005-59539 (FIG. 2) Japanese Patent Laid-Open No. 2000-117797 (FIG. 1) Japanese Unexamined Patent Publication No. 2000-15777 ((b) in FIG. 1)

  The present invention is intended to solve the above-described problems, and has a simple configuration, but can be used to adjust the distance between a large gear and each small gear that are practically sufficient, and a mold clamping device for an injection molding machine. The purpose is to provide. It is another object of the present invention to provide a mold clamping device of an injection molding machine that can smoothly move the pressure receiving plate or improve the parallelism of the moved pressure receiving plate with respect to the fixed plate to mold a good product.

According to a first aspect of the present invention, there is provided a mold clamping device for an injection molding machine, wherein a movable plate is movably disposed via a plurality of tie bars provided between a fixed plate and a pressure receiving plate, and the pressure receiving plate and the movable platen are movable. In a mold clamping device of an injection molding machine that opens and closes by a toggle mechanism provided between the panels, a tie bar with screws engraved on the outer periphery on the pressure platen side and a screw attached to the tie bar that is attached to the pressure platen A small gear that is engaged with each of the small gears, a ring-shaped large gear that is hollow on the center side, a support roller that is attached to the pressure receiving plate and can be adjusted in the surface direction perpendicular to the mold opening and closing direction, A driving mechanism for rotating the large gear, and a mold thickness adjusting mechanism in which the pressure receiving plate is movable in the mold opening and closing direction by driving of the driving mechanism. The inner peripheral portion of the large gear is a flange of the support roller. together they are pinched and supported between the large gear, type Characterized in that it is a possible positioning in the plane direction perpendicular to the closing direction.

According to a second aspect of the present invention, there is provided a mold clamping apparatus for an injection molding machine according to the first aspect, wherein the support roller is attached to the pressure receiving plate via an eccentric shaft, and the eccentric roller is rotated to rotate the eccentric shaft. The position is adjustable .

According to a third aspect of the present invention, there is provided a mold clamping device for an injection molding machine according to the second aspect, wherein the upper and lower two supporting rollers on the left side and the two upper and lower supporting rollers rotate the eccentric shaft of the supporting roller. The direction of adjustment is reversed .

  The mold clamping device of the injection molding machine that performs the mold opening / closing operation by the toggle mechanism of the present invention is capable of adjusting the position of the large gear in the surface direction orthogonal to the mold opening / closing direction, so that it has a simple configuration but is practically sufficient. The distance between the large gear and each small gear can be adjusted. As a result, the pressure receiving plate can be moved smoothly, or the parallelism of the pressure receiving plate after the movement to the fixed plate can be improved.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view of a mold clamping device of an injection molding machine according to the present invention. FIG. 2 is a side view of the mold clamping device of the injection molding machine of the present invention. FIG. 3 is a cross-sectional view of a support roller whose position can be adjusted with respect to the pressure receiving plate of the present invention. FIG. 4 is a front view of a support roller whose position can be adjusted with respect to the pressure receiving plate of the present invention. FIG. 5 is a diagram showing another embodiment. FIG. 6 is a diagram showing still another embodiment.

  The mold clamping device 11 of the injection molding machine is disposed on a bed (not shown) so as to face the injection device. As shown in FIG. 1, the mold clamping device 11 includes a stationary platen 13 to which a stationary mold 12 is attached, a pressure receiving plate 14 disposed in parallel to the stationary platen 13, and four pieces provided between the two. The tie bar 15 and the movable platen 17 to which the movable mold 16 is attached are provided. A known toggle mechanism 18 is disposed between the pressure receiving plate 14 and the movable plate 17. The toggle mechanism 18 includes a mold clamping servo motor 19 shown in FIG. 2, a motor-side pulley 20, a belt 21, a ball screw-side pulley 22, a ball screw 23, a ball nut 24, a cross head 25, and each link shown in FIG. 26. Then, a force is transmitted to the mechanism constituting the toggle mechanism 18 by driving the mold clamping servo motor 19 to move the movable platen 17 in the mold opening / closing direction.

  The mold thickness adjusting mechanism 27 of the mold clamping device 11 is attached to the side opposite to the fixed platen of the pressure receiving platen 14. A portion of the tie bar 15 on the pressure receiving plate side is provided with a screw 15a on the outer periphery. The portion of the screw 15a of the tie bar 15 protrudes from the vicinity of the four corners of the surface 14a of the pressure receiving plate 14 on the side opposite to the fixed plate. A small gear 28 having a threaded inner periphery is screwed onto the screw 15a of the tie bar 15. A gear attachment plate 29 is attached to the pressure receiving plate 14 by a plurality of bolts 30 on the side of the small gear 28 further on the side opposite to the fixed plate. Therefore, the small gear 28 is sandwiched between the pressure receiving plate 14 and the gear mounting plate 29 and attached to the pressure receiving plate 14 so as not to move in the mold opening / closing direction. Further, a large gear 31 is disposed inside the four small gears 28 on the side opposite to the fixed platen of the pressure receiving platen 14 so that the teeth 31a of the large gear 31 and the teeth 28a of the small gears 28 are engaged with each other. ing. The large gear 31 is a ring-shaped gear having a hollow center, and an inner peripheral portion 31 b is held by four support rollers 32 provided on the pressure receiving plate 14.

  As shown in FIGS. 3 and 4, one end of a columnar support portion 33 constituting the support roller 32 is fixed to the pressure receiving plate 14. A bottomed hole 33 a having a predetermined depth and a predetermined diameter is formed on the end surface of the support portion 33 opposite to the side fixed to the pressure receiving plate 14. A screw hole 33b into which the mounting bolt 34 is screwed is formed in the shaft core (center portion) of the bottomed hole 33a of the support portion 33. A cylindrical eccentric shaft 35 having a slightly smaller diameter than the bottomed hole 33a can be inserted into the bottomed hole 33a. The eccentric shaft 35 has a columnar shape with a predetermined length, and a through hole 35a into which a mounting bolt 34 is inserted into a portion (preferably about 1 mm to 2 mm) slightly deviated from the column axis is one end from the other end. It is provided for. The eccentric shaft 35 can be fixed to the support portion 33 by inserting the mounting bolt 34 into the through hole 35 a and screwing the mounting bolt 34 into the screw hole 33 b of the support portion 33 to be fixed. Yes. At this time, it is desirable to provide the inner peripheral surface of the bottomed hole 33a of the support portion 33 and the outer peripheral surface of the eccentric shaft 35 so as to be partially in contact with each other.

  Further, the eccentric shaft 35 is inserted into the bottomed hole 33a about 1/3 of one end portion, and a bearing 36 is attached to the outer peripheral surface on the other end side excluding that portion. A roller 37 is provided via a bearing 36. Therefore, the roller 37 is rotatable with respect to the eccentric shaft 35. Accordingly, the rotation center axis A of the roller 37 is eccentrically attached to the axis B of the mounting bolt 34 (which is also the axis of the support portion 33). Note that flanges 37a, 37a are provided at both ends of the roller 37 so as to protrude, and an inner peripheral portion 31b of the large gear 31 is provided so as to be in contact with a roller surface 37b sandwiched between the flanges 37a. The other end of the eccentric shaft 35 protrudes further than the roller 37 and the bearing 36, and a hexagonal engagement portion 38 is formed at that portion. The engaging portion 38 is a portion that is engaged when the eccentric shaft 35 is rotated by a spanner.

  A mold thickness adjusting motor 39 as a drive mechanism is attached to the side surface of the pressure receiving plate 14. A drive gear 40 is provided via a reduction gear attached to the drive shaft of the mold thickness adjusting motor 39, and the drive gear 40 is provided in mesh with the large gear 31. The mold thickness adjusting motor 39 may be a servo motor or an induction motor driven by an inverter.

  Next, the position adjustment of the large gear 31 with respect to the pressure receiving plate 14 or each small gear 28 will be described. In the present embodiment, the upper and lower support rollers 32 and 32 on the left side and the two upper and lower support rollers 32 and 32 on the right side are rotated in the reverse direction to adjust the eccentric shaft 35 of the support roller 32. Yes. In the left support roller 32 shown in FIG. 4, first, the mounting bolt 34 for fixing the eccentric shaft 35 of the support roller 32 is slightly loosened so that the eccentric shaft 35 can rotate with respect to the support portion 33. Then, a spanner is engaged with the engaging portion 38 and the eccentric shaft 35 is rotated in the counterclockwise direction C. Then, since the rotation center axis A of the roller 37 of the eccentric shaft 35 is displaced from the axis B of the mounting bolt 34, it moves to D in FIG. Then, along with the movement of the rotation center axis A of the roller 37, the outer periphery of the roller 37 is simultaneously moved to the position indicated by the alternate long and short dash line in FIG. Therefore, the inner peripheral portion 31b of the large gear 31 is pressed by the roller surface 37b, and the position of the large gear 31 is adjusted in a surface direction orthogonal to the mold opening / closing direction (a direction parallel to the surface 14a of the pressure receiving plate 14). . At the same time, the contact pressure between the roller 37 and the inner peripheral portion 31b of the large gear 31 can be adjusted. Then, the mounting bolt 34 is tightened again to fix the eccentric shaft 35 to the support portion 33 and the pressure receiving plate 14. The eccentric shaft 35 may be fixed directly to the pressure receiving plate 14 with the mounting bolt 34 without providing the support portion 33. Further, when the eccentric shaft 35 is fixed, other bolts or pins may be inserted.

  The purpose of adjusting the position of the large gear 31 in the direction orthogonal to the pressure receiving plate 14 in this way is to set the intervals between the large gear 31 and the small gears 28 to be substantially equal. The large gear 31 tends to abut against the upper two support rollers 32 and 32 more strongly than the lower two support rollers 32 and 32 due to its own weight. However, this can be prevented by adjusting the position of the support roller 32, and all the support rollers 32 can be brought into contact with the inner peripheral portion 31 b of the large gear 31 evenly. Thereby, all the intervals between the large gear 31 and each small gear 28 can be set to the same interval, and the backlash between the large gear 31 and each small gear 28 can be set equal.

  The mold thickness adjustment will be briefly described. The mold thickness adjustment is a control for moving the pressure receiving platen 14 to a position where the toggle mechanism 18 can perform the mold clamping most efficiently with the replacement of the mold. First, rotation drive is transmitted to the drive gear 40 and the large gear 31 through the reduction gear by driving the mold thickness adjusting motor 39 of the mold thickness adjusting mechanism 27. Then, the rotation is transmitted to the respective small gears 28 meshed with the large gear 31. At this time, since the backlash of the large gear 31 and each small gear 28 is set equal, the small gear 28 starts to rotate simultaneously. . Since the small gear 28 is screwed with the screw 15a of the tie bar 15, it moves in the mold opening / closing direction by rotation. Therefore, as the small gears 28 move, the four corners of the pressure receiving plate 14 can start to move substantially simultaneously, and the pressure receiving plate 14 can be moved smoothly. Further, when the driving of the mold thickness adjusting motor 39 is stopped, the backlash of the large gear 31 and each small gear 28 is set to be equal, so that the pressure receiving plate 14 is stopped while maintaining the parallelism with respect to the fixed platen 13. be able to. Therefore, the positioning accuracy of the pressure receiving plate 14 at the time of mold thickness adjustment can be improved.

  Further, the support roller only needs to be capable of moving the rotation center axis of the roller with respect to the pressure receiving plate, and may be as follows. That is, as shown in FIG. 5, an eccentric disk 41 may be used in place of the eccentric shaft 35 in the portion where the roller is attached. The eccentric disk 41 is provided with a roller support shaft 42 to which a roller 45 is rotatably attached at a predetermined distance from the rotation center axis E of the disk. Further, an arc-shaped long hole 43 is provided at a position having a constant radius from the rotation center axis E of the disk, and the long hole 43 can be locked by a bolt 44. Accordingly, the eccentric disc 41 is rotated by a predetermined angle to move the position of the roller 45 attached to the roller support shaft 42, and the eccentric disc 41 is fixed to the pressure receiving plate 14 by the bolts 44, thereby causing the large gear 31. And the position of the large gear 31 can be adjusted. The number of the long holes 43 and the bolts 44 can be selected as appropriate.

  As shown in FIG. 6, the support roller 51 may be adjusted with a bolt or the like. A mounting block 52 is fixed to the pressure receiving panel 14, and two push-pull bolts 53 are provided in the mounting block 52 so that they can be inserted. A roller support block 54 that supports the support roller 51 is attached to the attachment block 52 via the push-pull bolt 53 on the large gear 31 side. Therefore, the push / pull bolt portion 53a of the push / pull bolt 53 is rotated to adjust the positions of the mounting block 52 and the roller support block 54, and the bolt portion 53b is further screwed and fixed to thereby fix the roller support block 54 and the support roller. 51 can be fixed after moving.

  The above-described large gear position adjusting mechanism using the support roller is preferably provided in four support rollers, but may be provided in at least one or more locations. Further, pressing the support roller toward the inner peripheral portion of the large gear with a spring also prevents the large gear from tending to come into strong contact with only the upper support roller due to its own weight. You may make it make backlash equal.

  The present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be added without departing from the spirit of the invention.

It is a front view of the mold clamping apparatus of the injection molding machine of this invention. It is a side view of the mold clamping apparatus of the injection molding machine of this invention. It is sectional drawing of the support roller which can adjust a position with respect to the pressure receiving board of this invention. It is a front view of the support roller which can position-adjust with respect to the pressure receiving board of this invention. It is a figure which shows another embodiment. It is a figure which shows another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Clamping device 12 Fixed mold 13 Fixed board 14 Pressure receiving board 14a Board surface 15 Tieba 15a Screw 16 Movable mold 17 Movable board 18 Toggle mechanism 19 Servo motor 20 and 22 for mold clamping 21 Belt 23 Ball screw 24 Ball nut 25 Crosshead 26 link 27 mold thickness adjusting mechanism 28 small gear 28a, 31a tooth 29 gear mounting plate 30 bolt 31 large gear 31b inner peripheral portion 32 support roller 33 support portion 33a bottomed hole 33b screw hole 34 mounting bolt 35 eccentric shaft 35a through hole 36 Bearing 37 Roller 37a Flange 38 Engagement part 39 Mold thickness adjusting motor 40 Drive gear A, D Rotation center shaft B Shaft core C Counterclockwise

Claims (3)

Injection molding in which a movable platen is movably disposed through a plurality of tie bars provided between the fixed platen and the pressure platen, and a mold opening / closing operation is performed by a toggle mechanism provided between the pressure platen and the movable platen. In the mold clamping device of the machine,
A tie bar in which a screw is engraved on the outer periphery of the pressure platen side, a small gear that is attached to the pressure plate and screwed to the screw of the tie bar, and a center side that engages with each of the small gears is a ring-shaped ring that is hollow A large gear, a support roller attached to the pressure receiving plate and capable of adjusting the position in a plane direction orthogonal to the mold opening / closing direction, and a driving mechanism for rotating the large gear are provided, and the pressure receiving plate is driven by the driving mechanism. A mold thickness adjusting mechanism provided so as to be movable in the mold opening and closing direction is provided,
The inner peripheral portion of the large gear is sandwiched and supported between the flanges of the support roller, and
A mold clamping apparatus for an injection molding machine, wherein the position of the large gear can be adjusted in a plane direction orthogonal to the mold opening and closing direction. 2. The injection molding machine according to claim 1 , wherein the support roller is attached to the pressure receiving plate via an eccentric shaft, and the position of the support roller can be adjusted with respect to the pressure receiving plate by rotating the eccentric shaft. Clamping device. 3. The injection molding according to claim 2, wherein the two upper and lower support rollers on the left side and the two upper and lower support rollers on the right side have opposite directions to rotate and adjust the eccentric shaft of the support roller. Machine clamping device.

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