JPH10646A - Upright rotary injection-molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a upright rotary injection-molding machine of capable rotating a rotary table with small torque and, besides, calculating an accurate mold position simply and surely. SOLUTION: The rotary table 50 is provided with at least a flange part 53 at the underside about its rotating shaft, a circular follower part 51 with a teeth 54 cut in the outer peripheral surface, forming a circular driving part 63 with teeth 64 cut io the outer peripheral surface also in the driving shaft of a servo motor 61 of a table driving mechanism 60, and spreading a belt or chain member 70 to be engaged with the teeth between the circular driving part 63 and the circular driving part 51 of the rotary table 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vertical rotary injection molding machine, and more particularly to a rotary mechanism for a rotary table.

[0002]

2. Description of the Related Art A vertical rotary injection molding machine comprises a fixed plate having a plurality of lower dies arranged in a horizontal direction, a movable plate configured to be vertically movable with respect to the fixed plate, A rotary table provided below and having a plurality of upper dies facing the lower dies. The rotary table is configured to be able to move up and down together with the movable plate, and to be rotatable in the horizontal direction. At this time, a plurality of sets of dies including the lower die and the upper die are simultaneously joined and pressed at a plurality of rotation positions. Molding is performed.

As a rotating mechanism of a rotary table of this type of vertical rotary injection molding machine, there is a method in which a rotary shaft provided at the center of the rotary table is provided with a rotation angle indexing device, and is rotated by an electric motor or a hydraulic motor. General. However, in this method, since the center axis of the rotary table is rotated, the rotational moment of the mold on the rotary table becomes large. Therefore, in order to impart a rotational speed to the table with respect to this rotational moment, a large torque must be applied to the rotating shaft, and a high-precision indexing device and a large-capacity drive motor are required. In addition, in order to obtain an accurate molded product, it is indispensable to rotate the rotary table to an accurate position with respect to the lower mold to perform mold clamping. Since the position of the mold is determined by the rotation angle of the rotating shaft, the accuracy may decrease as the diameter of the table increases.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above points, and it is possible to rotate a rotary table with a small torque, and to easily and surely achieve a highly accurate mold position. It is an object of the present invention to provide a vertical rotary injection molding machine capable of performing indexing. Another object of the present invention is to provide a vertical rotary injection molding machine capable of rapidly rotating a rotary table.

[0005]

That is, a first aspect of the present invention is directed to a fixed plate disposed horizontally, a movable plate opposed to the fixed plate and vertically movable, and the movable plate. A vertical drive mechanism for driving the rotary table in the vertical direction, a rotary table installed on the lower surface side of the movable plate, moved up and down with the movable plate, and configured to be able to rotate forward and reverse in the circumferential direction, and the rotary table in a horizontal direction. A plurality of sets of gold including a plurality of lower dies installed on the fixed platen and a plurality of upper dies installed on the rotary table opposed to the lower dies. In a vertical rotary injection molding machine in which a mold can be simultaneously pressed at a plurality of rotation positions of the rotary table, the rotary table has at least a lower side around a rotation axis thereof. A circular driven portion having a flange portion and having a tooth portion formed on the outer peripheral surface is provided, and a circular drive portion having a tooth portion formed on the outer peripheral surface is also formed on the drive shaft of the servo motor of the table drive mechanism. A vertical rotary injection molding machine characterized in that a belt or a chain member meshing with the teeth is stretched between the circular drive section and the circular driven section of the rotary table.

According to a second aspect of the present invention, in the first aspect of the present invention, the rotation of the servo motor is controlled to accelerate substantially half of a predetermined rotation angle of the rotary table and to reduce substantially the other half to reduce the rotary table. The present invention relates to a vertical rotary injection molding machine that rotates.

[0007]

According to the vertical rotary injection molding machine of the present invention, the circular follower provided on the rotary table is connected and driven by the belt or chain member by the circular drive provided on the drive shaft of the servomotor. Therefore, the rotational moment is smaller than when the center axis of the rotary table is driven to rotate, and the table can be rotated with a small torque. Further, the belt or the chain member rotates while meshing with the teeth of the circular driven portion and the circular driving portion, so that the predetermined rotation angle of the rotary table is accurately rotated.

According to the second aspect of the present invention, the rotation of the servomotor is further controlled so that the rotary table is accelerated at approximately half the predetermined rotation angle and decelerated at approximately the other half of the rotation angle. The predetermined rotation angle of the rotary table can be rotated at the earliest, and the time for rotating the table can be reduced.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is an overall side view showing one embodiment of a vertical rotary injection molding machine according to the present invention, FIG. 2 is a sectional view taken along line 2-2 in FIG. 1, and FIG. FIG. 4 is a block diagram showing an example of rotation control of the rotary table.

As shown in FIG. 1, a vertical rotary injection molding machine 10 of the present invention includes a fixed platen 20, a movable platen 30, a vertical drive mechanism 40, a rotary table 50, and a table drive mechanism 60. Then, the rotary table 5 is fixed to the plurality of lower dies 13A and 13B on the fixed platen 20.
A plurality of upper dies 14A, 14B provided at the same time are jointly clamped at the plurality of rotational positions.

The fixed platen 20 is arranged on the base 11 in a horizontal direction. On the upper surface of the fixed platen 20, a plurality of lower molds,
Here, two lower dies 13A and 13B are installed at 180 ° angular positions. At the four corners of the fixed board 20, four stays 12 are provided upright between the upper board 15 and the upper board 15, and the movable board 30 is attached via the stays 12 so as to be vertically movable. The movable platen 30 is moved up and down along the stay 12 by the vertical drive mechanism 40 provided on the upper platen 15, and moves forward and backward in opposition to the fixed platen 20.

The vertical drive mechanism 40 is composed of a known hydraulic cylinder device 41. The piston rod 42 is connected to the movable plate 30. The movable plate 30 is moved up and down along the stay 12 by the expansion and contraction of the piston rod 42. To move forward and backward with respect to the fixed platen 20.

The rotary table 50 is mounted on the movable platen 30.
Is installed on the lower surface side of the
Upper dies 14A, 14 that can be combined with the lower dies 13A, 13B.
B is installed to form a plurality of sets of dies. In this embodiment, as described above, two upper dies 14A and 14B are installed at 180 ° angular positions corresponding to the two lower dies 13A and 13B, and two sets of dies (13A and 14A) are alternately provided.
A, 13B and 14B) (13A and 14B, 13B and 14A).

The rotary table 50 is mounted on the movable platen 30.
The table drive mechanism 60 is configured to be able to rotate forward and backward in the circumferential direction while moving up and down integrally with the vertical movement of the table. In the embodiment, the rotary table 50 is formed in a disk shape, and a circular driven portion 51 is formed on a side surface thereof. As shown in the figure, the circular driven portion 51 is a portion on which a transmission member 70 formed of a belt or a chain member is stretched and is driven to rotate by the driving force of a table driving mechanism 60.
, And has a flange portion 53 at least on the lower side, and a tooth portion 54 is engraved on the outer peripheral surface.

The flange portion 53 is for preventing the transmission member 70 from falling off from the circular driven portion 51, and may be provided above the circular driven portion 51 if necessary. Needless to say, the teeth 54 are provided corresponding to the transmission member 70 formed of a belt or a chain member.

The table driving mechanism 60 is provided integrally with the movable platen 30 and has a known servomotor 61. The servo motor 61 rotates the rotary table 50 in the horizontal direction, and can be switched in either forward or reverse direction by a setting signal. The drive shaft 62 of the servomotor 61 is formed with a circular drive portion 63 having teeth 64 on the outer peripheral surface. This circular drive 63
Transmits the rotation of the drive shaft 62 of the servomotor 61 to the circular follower 51 provided on the rotary table 50 via a transmission member 70 formed of a belt or a chain member.

That is, as is well understood from FIG. 2, the rotation of the servo motor 61
The power is transmitted to the rotary table by a transmission member 70 formed of a belt or a chain member stretched between the rotary table 3 and the circular driven portion 51 of the rotary table 50. In addition,
Reference numeral 65 in the figure denotes an idler pulley for adjusting the tension of the transmission member 70.

As the transmission member 70, a known rubber belt or a transmission roller chain is used. Servo motor 6
1 to effectively transmit the driving force of the table drive mechanism 60 to the circular follower 51 and rotate the rotary table 50 with high precision. The portion 64 and the teeth 54 of the circular follower 51 of the rotary table 50 mesh with each other. That is, when a belt is used for the transmission member 70, a toothed belt or a chain member in which a concave and convex portion (not shown) having a pitch that meshes with the tooth portion 64 is provided on a surface that rubs against the circular driving portion 63. In the case of using a sprocket, the sprocket has the number of chain pitches that mesh with the teeth 64.

As described above, the use of the circular driving portion 63, the circular driven portion 51, and the transmission member 70 composed of a belt or a chain connecting the both enables accurate rotation, and ensures acceleration and deceleration. It can be performed smoothly. Further, since the rotation of the servomotor 61 is transmitted from the small-diameter circular drive section 63 to the large-diameter circular driven section 51, the generated torque is small, and the acceleration and deceleration can be performed easily and reliably. Further, since the index of the rotation angle of the rotary table 50 is determined by the length of the transmission member 70 sent out by the rotation of the circular drive unit 63, stable and high accuracy can be obtained.

The circular follower 51 and the circular drive 6
The ratio of the diameter to 3 or the ratio of the number of the tooth portions 64 and 54 is appropriately determined depending on how much the rotation speed of the circular drive unit 63 by the servo motor 61 is reduced on the circular follower unit 51 side. If the ratio is too large, the contact area of the transmission member 70 in the circular drive unit 63 decreases, and the transmission of rotation is not efficient. In this example, the ratio is 450: 28.

Next, the invention of claim 2 will be described. According to the present invention, in the vertical rotary injection molding machine of the above embodiment, the rotation control of the circular driven portion 51 of the rotary table 50 by the servo motor 61 is performed as follows. For a predetermined rotation angle, control is performed so that approximately half of the rotation angle is accelerated and the other approximately half is decelerated. That is, for example, when the rotary table 50 is rotated by 180 ° to rotate the mold by 180 ° as shown in this example, if the acceleration and deceleration speeds of the servo motor 61 are the same, as shown in the present invention. To a rotation angle of 90 °, then 180
If the servo motor is decelerated to an angle of °, the servo motor always performs acceleration / deceleration operation, and an average rotational performance is obtained, so that the servo motor can reach the target angle in the shortest time.

FIG. 3 is a graph showing the relationship between the motor rotation speed and the rotation angle arrival time. The solid line in the graph is an example in which the rotary table and the servomotor of the injection molding machine of the present invention described in FIG. As shown in this example, when the rotary table is rotated by 180 °, the rotation angle is accelerated to 90 °, and when the rotary table is decelerated to 180 ° thereafter, the time required for the table to rotate 180 ° is 2 seconds, Was a maximum of 30 rpm. Using the same rotary table and servomotor, the rotary table was accelerated up to a rotation angle of 45 °, and thereafter rotated at a constant speed up to 135 ° and decelerated from 135 ° to 180 °. The time required for the .RTM. To rotate 180.degree. Was 2.121 seconds, and the average rotation speed of the servo motor was 10.605 rpm. The result is shown by a dotted line in the graph.

Next, an example of a control mechanism in the table driving mechanism of the injection molding machine according to the present invention will be described with reference to FIG. In the reference numerals in the drawings, the same reference numerals as those in FIGS. 1 and 2 indicate the same members. The table drive mechanism 60 includes a servomotor 61 and a circular drive section 63 provided on a drive shaft 62 of the servomotor 61. As shown in FIG. Are linked. The servo motor 61 is rotatable in both forward and reverse directions by a signal from a rotation speed setting device. The servo motor 61 includes an encoder that detects a rotation angle of the drive shaft 62 and generates a signal corresponding to the rotation angle, and transmits the signal to a position / speed converter and a rotation speed setting device. ing. The rotation speed setting unit is set in advance with a rotation program that accelerates approximately half the rotation angle of the rotary table and decelerates the other half. The control unit calculates a rotation speed signal of the rotary table corresponding to the rotation speed of the servo motor. Then, in accordance with the rotation speed signal, the current control unit and the power conversion unit increase or decrease the power for rotating the servomotor, and the rotation speed is controlled and adjusted.

[0024]

As described above, according to the vertical rotary injection molding machine of the present invention, the belt driven by the circular follower provided on the rotary table is provided by the circular drive provided on the drive shaft of the servomotor. Alternatively, since the connection drive is performed by a chain member, the rotational moment is smaller than when the center axis of the rotary table is rotationally driven, and the table can be rotated with a small torque. Further, since the belt or chain member rotates while meshing with the teeth of the circular driven portion and the circular driving portion, the predetermined rotation angle of the rotary table can be accurately rotated.

Further, according to the second aspect of the present invention, the rotation of the servomotor is controlled so that the rotary table is accelerated at approximately half the predetermined rotation angle and decelerated at approximately the other half of the rotation angle. The time required to reach the rotation angle is the shortest, the rotary table can be rotated in a short time, and efficient work can be performed.

[Brief description of the drawings]

FIG. 1 is an overall side view showing an embodiment of a vertical rotary injection molding machine according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 in FIG.

FIG. 3 is a graph showing a relationship between a rotation speed of a servomotor and a rotation angle arrival time of a rotary table.

FIG. 4 is a block diagram illustrating an example of rotation control of a rotary table.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vertical rotary injection molding machine 20 Fixed board 30 Movable board 40 Vertical drive mechanism 50 Rotary table 51 Circular driven part 52 Rotary shaft 53 Flange part 54 Teeth part 60 Table drive mechanism 61 Servo motor 62 Drive shaft 63 Circular drive part 64 Teeth Part 70 Transmission member

Claims (2)

[Claims] A fixed plate arranged in a horizontal direction, a movable plate opposed to the fixed plate so as to be movable up and down, an up-down drive mechanism for driving the movable plate up and down, A rotary table installed on the lower surface side of the board and moved up and down together with the movable board and configured to be able to rotate forward and backward in the circumferential direction, including a table drive mechanism having a servomotor that drives the rotary table in the horizontal direction, A plurality of sets of dies including a plurality of lower dies installed on the fixed platen and a plurality of upper dies installed on the rotary table facing the lower die are simultaneously placed at a plurality of rotation positions of the rotary table. In a vertical rotary injection molding machine capable of pressing, the rotary table has a flange portion at least on a lower side around a rotation axis thereof, and a tooth portion is engraved on an outer peripheral surface. A circular driven portion having a toothed portion formed on the outer peripheral surface is also formed on the drive shaft of the servo motor of the table driving mechanism, and the circular driven portion and the circular driven portion of the rotary table are provided. A vertical rotary injection molding machine, wherein a belt or a chain member meshing with the teeth is stretched between them. 2. A vertical rotary machine according to claim 1, wherein said servomotor is controlled to rotate to rotate said rotary table by accelerating substantially half of a predetermined rotation angle of said rotary table and decelerating the remaining half. Type injection molding machine.