JP2997137B2 - Vertical rotary 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 a vertical rotary injection molding machine for injection-molding a composite molded article such as multicolor molding or multilayer molding using a plurality of colors or a plurality of kinds of resins. The present invention relates to a vertical rotary injection molding machine using a servomotor as a rotary drive source of a table.

[0002]

2. Description of the Related Art Conventionally, a lower die and an upper die which are installed on a fixed platen and a rotary table at an angle of 180 degrees or 120 degrees with respect to a rotation axis of the rotary table, respectively, are attached to the rotary table by 180 degrees or 120
2. Description of the Related Art There has been known a vertical rotary injection molding machine which repeats injection molding by sequentially combining a plurality of rotation positions such as a degree unit to form a composite molded product. In these vertical rotary injection molding machines, a mechanical indexing device using a cam mechanism has been used as a mechanism for rotating a rotary table in accordance with a set rotational position. When this mechanical indexing device is used, there is a problem that a general device currently on the market is stopped at two stages when, for example, a two-stage indexing angle is set and reversed and then returned. Also, various techniques for improving the cycle of injection molding have been proposed. Furthermore, in order to obtain a high quality molded product, it is necessary to accurately close and close the mold composed of the upper mold and the lower mold,
For this purpose, it has been required to hold the rotary table on which the upper die is mounted at an accurate rotational position and close and close the die.

[0003]

In order to increase the cycle of injection molding, it is effective to rapidly accelerate the stopped rotary table to the maximum rotation speed, and to quickly decelerate from the maximum rotation speed to stop. . It is also effective to increase the maximum rotation speed at this time.

However, it is difficult to quickly accelerate and stop the rotary table quickly because the moment of inertia of the rotary table on which the upper die is mounted is large. In particular, when the rotary table rotating at a high speed is stopped, the rotary table may slightly swing. In such a case, it is necessary to wait for the swing to subside to close the mold in order to close the mold accurately, and the swing when the rotary table is stopped sometimes hinders the cycle up. In addition, if the mold is closed before the swing has stopped, accurate mold closing may not be realized. Alternatively, if the rotation speed is reduced in order to stop the swinging quickly while stopping the swinging, the time required for one cycle of injection molding becomes longer, which is against the cycle up.

Accordingly, the present invention accelerates the rotary table to the maximum rotation speed, and quickly reduces the speed from the maximum rotation speed to accurately stop the rotation table, thereby enabling the cycle of injection molding to be performed, and in addition, accurate mold closing. It is an object of the present invention to provide a vertical rotary injection molding machine capable of performing the following.

[0006]

In order to solve this problem, a vertical rotary injection molding machine according to the present invention is provided with a fixed plate arranged along a horizontal direction, and opposed to the fixed plate. A movable plate capable of moving up and down to change the relative position with respect to the fixed plate, an up-down drive mechanism for driving the movable plate up and down, and a movable plate disposed on the lower surface of the movable plate so as to be movable up and down together with the movable plate A rotary table capable of rotating forward and reverse along the circumferential direction, a servo motor drive mechanism for driving the rotary table to rotate forward and reverse, and a rotation angle detecting means for detecting a rotation angle of the rotary table from a set reference position. And 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, and a plurality of rotation positions of the rotary table. At the same time In the vertical rotary injection molding machine capable of being tightened, the servo motor driving mechanism is set at least once between a plurality of acceleration stages and the plurality of acceleration stages according to the rotation angle of the rotary table during acceleration. The rotary table is accelerated to a predetermined rotation speed by an acceleration step including a constant speed step, and at the time of deceleration, at least one time is set between a plurality of deceleration steps and the plurality of deceleration steps according to the rotation angle of the rotary table. The rotary table is decelerated and stopped by a deceleration step including a constant speed step.

[0007]

In the vertical rotary injection molding machine having the above-mentioned structure, prior to injection molding, a plurality of lower dies are mounted on a fixed plate, and are arranged on a lower surface of a movable plate installed opposite to the fixed plate. The same number of upper dies as the lower dies are mounted on the rotary table.

First, the movable platen and the rotary table are moved down by operating the up-down drive mechanism to close and close a plurality of sets of upper and lower dies. Subsequently, the molten resin is injected into the mold to form the first layer. Thereafter, the movable platen and the rotary table are raised by operating the vertical drive mechanism to open the mold. At this time, the formed first layer is adhered and held on the upper mold.

After the mold is opened, the servo motor driving mechanism drives the rotary table to rotate so that the rotary position of the rotary table is set according to the arrangement of the lower mold and the upper mold. At this time, the servomotor drive mechanism first accelerates the rotary table in an acceleration step. In the acceleration step, the servo motor driving mechanism rotationally accelerates the rotary table in the stopped state under the set acceleration condition (first acceleration stage). When the rotation angle detecting means detects that the rotary table is at the rotation angle set to start the constant speed rotation, the servo motor drive mechanism drives the rotary table to rotate at a constant speed (constant speed step). Further, when the rotation angle detecting means detects that the rotary table is at the rotation angle set to end the constant speed rotation, the servo motor driving mechanism accelerates the rotation of the rotary table (second acceleration stage). In addition, the third and lower acceleration steps and constant velocity steps are performed according to the setting. In this manner, the rotary table is accelerated to a predetermined rotation speed in an acceleration step including a plurality of acceleration stages and a constant speed stage set at least once between the plurality of acceleration stages.

Subsequently, when the rotation angle detecting means detects that the rotary table is at the rotation angle set to start the deceleration step, the servo motor drive mechanism sets the rotary table at a predetermined rotation speed. Decelerate under the deceleration condition (first deceleration stage). When the rotation angle detecting means detects that the rotary table is at the rotation angle set to start the constant speed rotation, the servo motor drive mechanism drives the rotary table to rotate at a constant speed (constant speed stage). Further, when the rotation angle detecting means detects that the rotary table is at the rotation angle set to end the constant-speed rotation,
The servo motor drive mechanism reduces the rotation of the rotary table (second deceleration stage). In addition, a third or lower deceleration step and a constant velocity step are performed by setting. In this manner, in the deceleration step including the plurality of deceleration stages and the constant speed stage set at least once between the plurality of deceleration stages, the rotary table is decelerated and stopped at the set rotation position.

Since the rotary table is accelerated in a plurality of acceleration stages with a constant speed stage interposed, even a rotary table having a large moment of inertia can be quickly accelerated to reach the maximum rotation speed. Further, since the rotary table is decelerated in a plurality of deceleration stages including the constant speed stage, the rotary table having a large moment of inertia can be quickly decelerated and accurately stopped. In addition, the rotary table does not swing during the stop. In this way, the rotary table can be quickly accelerated to the maximum rotation speed, and then quickly decelerated from the maximum rotation speed and stopped accurately, so that the cycle of injection molding can be increased, and accurate mold closing can be achieved. Is achieved.

[0012]

Next, a preferred embodiment of the present invention will be described with reference to the drawings. First, the configuration of the vertical rotary injection molding machine 10 of the present embodiment will be described with reference to FIG. A fixed board 14 is mounted on a gantry 12 fixed to a base (not shown). On this fixed platen 14, the lower mold 1 of two molds is placed.
6a and 16b are installed. In addition, four columnar stays 18 are erected on the fixed board 14 along the vertical direction indicated by the arrow X. A movable platen 22 having four sliding portions 20 through which the stay 18 is slidably inserted is attached to the stay 18.

Below the movable platen 22, a two-stage rotary table 2 rotatable in the horizontal direction indicated by an arrow Y
4 are arranged. In this rotary table 24,
Upper dies 26a and 26b that are paired with the lower dies 16a and 16b on the fixed platen 14 are attached. The molding die 2 is formed by the lower dies 16a and 16b and the upper dies 26a and 26b.
7 will be constituted. Further, on the movable platen 22, a rotation drive unit 28 is provided. This rotation drive unit 28
Drives the rotary table 24 to rotate, the details of which will be described later.

Further, a pair of mold clamping piston rods 30a and 30b are connected to the movable platen 22. The mold-clamping piston rods 30a, 30b pass through an upper plate 32 fixed to the stay 18 above the movable plate 22, and the upper plate 3
2 and a pair of mold clamping cylinders 34a, 34b
It is connected to a piston (not shown) which is slidably inserted into the inside. The mold clamping cylinders 34a and 34b are capable of reciprocatingly driving the mold clamping piston rods 30a and 30b in the direction of the arrow X in accordance with the supply and discharge of hydraulic oil by a hydraulic device (not shown). The movable platen 22 and the rotary table 2
4 is driven reciprocally according to the reciprocating motion of the mold clamping piston rods 30a and 30b. Thereby, the mold clamping cylinder 34
The movable platen 22 and the rotary table 24 can be driven up and down by operating the supply and discharge of the hydraulic oil to and from the a and b. In addition, it is possible to perform mold closing, mold clamping, and mold opening operations by bringing the upper dies 26a, 26b mounted on the rotary table 24 close to and away from the lower dies 16a, 16b. That is, the mold clamping piston rods 30a, 30b
The mold clamping cylinders 34a and 34b constitute the vertical drive mechanism of the present invention.

Next, the detailed structure of the rotary drive unit 28 and the rotary table 24 will be described with reference to FIG. The rotation drive unit 28 includes a servomotor 36 as a drive source, a worm 38 connected to a rotation shaft of the servomotor 36, a worm wheel 40 meshing with the worm 38, and a first gear 42 coaxially connected to the worm wheel 40. , First gear 42
A second gear 44 having a rotation axis parallel to the first gear 42 and meshing with the first gear 42, a hollow shaft 46 coaxial with the second gear 44 and fixed through the second gear 44 and a worm 38.
And an encoder 48 capable of detecting the number of rotations of the worm 38 and outputting a signal corresponding thereto.

The first gear 42 and the second gear 44 are capable of minutely changing their relative positions along their respective axial directions. The shaft 46 is supported by a thrust self-aligning roller bearing 49 interposed between the movable platen 22 and the shaft 46 so as to be minutely movable in the axial direction, and passes through the movable platen 22 to the rotary table 24. Are linked. As a result, the rotary table 24 is
Is suspended from the movable platen 22 via the

The shaft 4 supporting the rotary table 24
Since the load of the rotary table 24 acts on 6 in the direction of arrow B, the shaft 46 is slightly moved in the direction of arrow B against the bearing force of the thrust self-aligning roller bearing 49. Therefore, a gap is formed between the movable platen 22 and the rotary table 24 according to the amount of movement of the shaft 46 in the direction of arrow B.

On the other hand, the servo motor 36 is supplied with driving power from a power supply device (not shown) and can be driven to rotate in the direction of arrow P. The rotation of the servo motor 36 in the direction of the arrow P is converted into the rotation in the direction of the arrow Q by the worm 38, the worm wheel 40, the first gear 42, the second gear 44, and the shaft 46, and the rotary table 24 is indicated by the arrow Q. It can be driven to rotate in the direction. At this time, since the above-mentioned gap is formed between the rotary table 24 and the movable platen 22, they do not come into contact with each other when the rotary table 24 rotates. For this reason, the rotation of the rotary table 24 becomes smooth, and the generation of foreign matters such as metal strips due to the contact between them is prevented. Also,
The movable platen 22 and the rotary table 24 are connected to the mold clamping cylinders 34a,
4b, the mold is closed and clamped by a force acting on the rotary table 24 via the molding die 27 along the direction opposite to the arrow B.
Can be closely attached to the movable platen 22. At this time, the shaft 46 slightly moves along the direction opposite to the arrow B, and the relative position of the second gear 44 and the first gear 42 along the axial direction also changes according to the movement of the shaft 46. I do.

The output from the encoder 48 is supplied to a control unit 50 electrically connected to the encoder 48.
Can be entered. The control unit 50 is also electrically connected to the servomotor 36,
Control signals from 0 can be input to the servomotor 36. The servo motor 36 to the encoder 48 constituting the rotation drive unit 28 and the control unit 50 constitute a servo motor drive mechanism of the present invention.

As shown in FIG. 6, the control unit 50 includes a pattern selection digital switch 52, a maximum speed setting digital switch 54, and a mode selector 56.
A well-known microcomputer (not shown) is built in. Programs for executing various processes are stored in the microcomputer in advance, and the control unit 50 can execute control processes according to the programs and various instructions input from the outside. The control unit 50 can detect the number of rotations of the servomotor 36 based on a signal from the encoder 48, and integrates the signal of the encoder 48 to rotate the rotary table 24 from the reference position corresponding to the integrated value. The angle can be detected. Therefore, the control unit 50 also has a function as a rotation angle detecting means together with the encoder 48.

Referring to FIGS. 6 and 7, the setting of the mode, pattern and maximum speed will be described. First, there are four modes that can be selected by the mode selector 56.
Since mode 0 is a mode in which the rotary table 24 is not rotated, there is no setting of the pattern and the maximum speed at that time.

As shown in FIG. 7, in mode 1, the rotary table 24 is rotated 120 ° from the origin (pattern 1), and then rotated 120 ° in the same direction (pattern 2).
Finally, the mode is returned by 240 ° (pattern 3) to return to the origin. In mode 2, the rotary table 24 is rotated by 240 ° from the origin (pattern 4), and then rotated by 120 °
In this mode, the lens is rotated in the returning direction (pattern 5) and further returned by 120 ° (pattern 6) to return to the origin. Mode 3 is a mode in which the rotary table 24 is rotated 180 ° from the origin (pattern 7), and then rotated in the direction of returning 180 ° (pattern 8) to return to the origin.

The setting of the maximum speed is set by the operator for each pattern constituting each of the modes 1 to 3. For example, when setting the maximum speed for each pattern of mode 1, mode 1 is first selected by the mode selector 56. Then, set the pattern selection digital switch 52 to P
1 to select pattern 1. Next, the maximum speed setting digital switch 54 is set to, for example, 80. As a result, the maximum speed of the pattern 1 is set to 80% of the rated speed. Similarly, the maximum speed of pattern 2 and pattern 3 is set by setting the pattern selection digital switch 52 to P2 and P3. The same applies to the setting of the maximum speed of each pattern in mode 2 or mode 3.

When the maximum speed is set by the operator in this manner, the control unit 50 creates an acceleration / deceleration model as illustrated in FIG. 8 for each of the patterns 1 to 8 according to the set maximum speed. Referring to the example shown in FIG. 8, A1, A2, and A3 indicate an acceleration stage, C
1, C2, C4 and C5 are constant speed stages, R1, R2 and R3 are deceleration stages, and C3 is a constant speed state at a set maximum speed. Acceleration rate of A1 to A3, R1
The deceleration rate of R3, the rotation angle of the rotary table 24 at which acceleration or deceleration should be started, and the speeds of C1 to C5 are automatically determined by the control unit 50 according to preset conditions.

Here, the description will return to the movable platen 22 and the rotary table 24 again. As shown in FIGS. 2 and 3, a hydraulic cylinder 58 having an axis along the rotational tangential direction of the rotary table 24 and a hydraulic cylinder 58 near two sliding portions 20 of the movable platen 22 located on the left side in FIG. Buffer mechanism 62a with piston 60 and similar buffer mechanism 62
b is provided. Further, the rotary table 24 includes an extending member 66a and an extending member 66b provided with contact portions 64a and 64b capable of contacting the contact end 60a of the hydraulic piston 60 along the axial direction of the hydraulic piston 60. Is provided at a position forming an angle of about 60 ° with the center of the apex as the vertex. Thus, when the rotary table 24 rotates in the direction of arrow R, the contact portion 64a can abut on the buffer mechanism 62a, and when the rotary table 24 rotates in the direction of arrow L, the buffer mechanism The contact portion 64b can contact the contact portion 62b. However,
During normal operation, the rotary table 24 is
a and the contact portion 64a, and between the buffer mechanism 62b and the contact portion 64b, the rotation is stopped at a position where a predetermined space is maintained, so that the buffer mechanism 62a, the contact portion 64a, and the buffer mechanism 62b are stopped. And the contact portion 64b do not contact each other. That is, the rotary table 2 during normal operation
4 is a cushioning mechanism 62a, 62b and a contact portion 64a,
The rotation position is changed along the directions of the arrows R and L within the range of the rotation angle at which the rotation position does not come into contact with 64b. In this embodiment, the rotation angle range of the rotary table is set to 180 °.

As shown in FIG. 5, the shock absorbing mechanisms 62a, 62
b is constituted by a hydraulic piston 60 inserted into the hydraulic cylinder 58. The hydraulic cylinder 58 is provided with an oil passage hole 58b communicating with an oil chamber 58a filled with hydraulic oil. Further, a relief circuit 68 shown in FIG. 5B is connected to the oil passage hole 58b. The relief circuit 68 includes a first oil passage 70 communicating with the oil passage hole 58b, a second oil passage 74 connected to the first oil passage 70 via a check valve 72, and a third oil branched from the first oil passage 70. Road 75 and second oil passage 7
4 is constituted by a relief valve 78 installed at an end opposite to the check valve 72. The other end of the third oil passage 75 is connected to a hydraulic pump (not shown) via a check valve 76. The configuration is such that hydraulic oil is supplied from the hydraulic pump to the first oil passage 70 via the check valve 76 and the third oil passage 75. As a result, the hydraulic piston 60 is pressed along the arrow Z direction, and the oil chamber 58a and the oil passage hole 58
When the pressure exerted on the relief circuit 68 via the hydraulic oil in b exceeds the set pressure of the relief valve 78, the hydraulic oil can be purged through the relief valve 78 to reduce the pressure, and the pressure of the hydraulic oil can be reduced. Hydraulic piston 6 according to purge
It is possible to move 0 along the arrow Z direction.

As shown in FIG. 3 and FIG.
3, a positioning mechanism 82 provided with a positioning pin 80 that reciprocates along the axial direction of the movable platen 22 is provided. As shown in FIG. 4, the positioning mechanism 82 is connected to the movable platen 22 through a plurality of bolts 84.
Attached to. A substantially rectangular parallelepiped portion connected to the bolt 84 is a pin driving unit 86, and includes a driving member 88 that is inserted into the pin driving unit 86 so as to be able to reciprocate. A positioning pin 80 is connected to a tip end of the driving member 88 that is exposed from the pin driving section 86. As a result, the positioning pin 80 is driven up and down by the pin driving unit 86 via the driving member 88 along the arrow U direction and the arrow D direction.

Further, the rotary table 24 is provided at a position corresponding to the positioning pin 80 with a positioning hole 90a into which the positioning pin 80 can be fitted. Therefore, when the positioning pin 80 descends in the direction of arrow D, the tip of the positioning pin 80 fits into the positioning hole 90a to fix the relative position along the circumferential direction between the movable platen 22 and the rotary table 24. It is possible. When the positioning pin 80 moves up in the direction of arrow U, the positioning pin 80
Is disengaged from the positioning hole 90a,
The relative position of the rotary table 24 and the rotary table 24 in the circumferential direction is not fixed. In FIG. 4, the left side of the drawing shows the state in which the positioning pin 80 has risen along the arrow U direction, and the right side of the drawing shows the state in which the positioning pin 80 moves down in the direction of arrow D to position the leading end. The state where it was fitted in the hole 90a is shown.

The rotary table 24 is provided with a positioning hole 90b at a position which is rotationally symmetric with respect to the positioning hole 90a by 180 °. Therefore, the rotary table 2
When the position 4 rotates and the relative rotation position with respect to the movable platen 22 is displaced by 180 °, the positioning mechanism 82 comes to a position corresponding to the positioning hole 90b. At this time, it is possible to lower the positioning pin 80 along the arrow D direction so that the tip of the positioning pin 80 fits into the positioning hole 90b. As a result, the relative rotation position between the movable platen 22 and the rotary table 24 was displaced by 180 ° in a state where the positioning pin 80 was fitted in the positioning hole 90a and a state where the positioning pin 80 was fitted in the positioning hole 90b. It can be fixed in the state.

The positioning pin 80 is positioned at a positioning hole 90a.
The movable platen 22 and the rotary table 24 are lowered in a state where they are fitted with the positioning holes 90b, respectively.
4, the upper dies 26a and 26b installed on the rotary table 24 are accurately joined to the lower dies 16a and 16b installed on the fixed platen 14, and the molds are closed and clamped.
Therefore, the positioning mechanism 82 has the positioning holes 90a, 90b.
By fitting the positioning pins 80 into the rotary table 24, the relative position between the rotary table 24 and the movable platen 22 is fixed, and the relative position between the rotary table 24 and the fixed platen 14 is properly fixed.

Next, the operation of the vertical rotary injection molding machine 10 having the above configuration will be described. Prior to the operation of the vertical rotary injection molding machine 10, the rotary table 24
Set the rotation position of. The rotation position of the rotary table 24 according to the molded product is automatically set by selecting a mode with the mode selector 56 of the control unit 50. For example, when the mode 3 is selected, the rotation is repeated 180 ° clockwise from the reference position, stopped, and then rotated 180 ° in the opposite direction to return to the reference position. Next, the pattern selection digital switch 52 is operated to P7 to select the pattern 7, and the maximum speed setting digital switch 54 is selected.
Is set to, for example, 80. As a result, a speed corresponding to 80% of the rated maximum rotation speed is set as the maximum speed. Similarly, the maximum speed of the pattern 8 is set to, for example, 80. Once the maximum speed is set by the operator,
The control unit 50 sets an acceleration / deceleration model as illustrated in FIG. 8 for each of the patterns 7 and 8 according to the set maximum speed. That is, the acceleration rates A1, A2 and A3, and the rotational speeds C1, C2, C4 and C
5. The control unit 50 automatically determines the deceleration rates R1, R2 and R3 and the rotation angle of the rotary table 24 at which acceleration or deceleration is to be started, according to the set maximum speed C3. After setting the mode and the maximum speed for each pattern corresponding to the mode, the operator starts the vertical rotary injection molding machine 10.

When the vertical rotary injection molding machine 10 is started, the control unit 50 executes the control shown in FIG.
In this control, first, the control unit 50 determines which mode is selected (step 100).
0). When it is determined that the mode 1 has been selected, the rotation control of the rotary table 24 according to the pattern 1 is executed (step 2000). Subsequently, the rotation of the rotary table 24 is controlled by the pattern 2 (step 3).
000). Rotary table 2 with pattern 3
The rotation control of No. 4 is executed (step 4000). Also,
If it is determined that the mode 2 has been selected, the rotation of the rotary table 24 is controlled by the pattern 4 (step 5000). Subsequently, the rotation of the rotary table 24 is controlled by the pattern 5 (step 600).
0). Further, rotation control of the rotary table 24 according to the pattern 6 is executed (step 7000). Alternatively, when it is determined that the mode 3 is selected, the pattern 7
(Step 8000). Subsequently, the rotation of the rotary table 24 is controlled by the pattern 8 (step 900).
0). After executing the control in one of the modes, the process returns.

The control corresponding to patterns 1 to 8 executed by the control unit 50 will be described with reference to FIGS. 8 and 10. For example, when the control unit 50 determines that the mode 3 is selected in step 1000, the control unit 50 starts a pattern 7 routine shown in FIG. Control unit 5
0 instructs the servo motor 36 of the rotation drive unit 28 to rotate the rotary table 24 at a rotational speed corresponding to the preset acceleration rate A1 (step 8010). Subsequently, based on a signal input from the encoder 48 to the control unit 50, it is determined whether the rotation speed of the rotary table 24 has reached a preset speed C1 by acceleration at the acceleration rate A1 (step 8020). At this time, if the detected rotation speed of the rotary table 24 and the set rotation speed C1 are within a set error range, it is determined that the rotation speed of the rotary table 24 has reached C1. The same applies to the determination of the rotation speed of the rotary table 24 in the following steps. If it is determined that the rotation speed of the rotary table 24 <C1, step 80 is executed.
10, the rotation speed of the rotary table 24 = C1
If it is determined, the process proceeds to the next step. When proceeding to the next step, the control unit 50 instructs to maintain the rotation speed of the servo motor 36 at a rotation speed corresponding to the rotation speed C1 of the rotary table 24 (step 8030). Further, based on a signal from the encoder 48, it is determined whether or not the rotation angle of the rotary table 24 has reached the rotation angle at which the acceleration stage at the acceleration rate A2 should be started (step 804).
0). If the rotation angle of the rotary table 24 has not reached the A2 start angle, the flow returns to step 8030, where A2
When it is determined that the start angle has been reached, the process proceeds to the next step.

In the following steps, the above step 801
Acceleration at the acceleration rate A2 (step 8)
050), the rotation speed = C2 is determined (step 806).
0), the rotation speed = C2 is maintained (step 8070), it is determined whether or not the rotation angle at which the acceleration at the acceleration rate A3 is to be started is reached (step 8080), and the acceleration is performed at the acceleration rate A3 (step 8)
090), control is performed to determine rotation speed = maximum rotation speed C3 (step 8100) and to hold rotation speed = maximum rotation speed C3 (step 8110).

Following these executions, the control unit 50
Determines whether the rotation angle of the rotary table 24 has reached the rotation angle at which deceleration at the deceleration rate R1 should be started (step 8120). If it is determined that the rotation angle has not been reached, the process returns to step 8110. If it is determined that the rotation angle of the rotary table 24 has reached the rotation angle at which deceleration at the deceleration rate R1 should be started, the control unit 50
Instructs the servo motor 36 to rotate at a rotation speed corresponding to the preset deceleration rate R1 of the rotary table 24 (step 8130). Subsequently, a signal input from the encoder 48 to the control unit 50 indicates a deceleration rate R1.
It is determined whether the rotation speed of the rotary table 24 has reached the preset speed C4 by the deceleration in (8140). Rotation speed of rotary table 24> C
When it is determined to be 4, the process returns to step 8130. If it is determined that the rotation speed of the rotary table 24 is equal to C4, the control unit 50 instructs to maintain the rotation speed of the servo motor 36 at a rotation speed corresponding to the rotation speed C4 of the rotary table 24 (step 8150). next,
According to a signal from the encoder 48, the rotary table 2
It is determined whether the rotation angle of No. 4 has reached the rotation angle at which the deceleration stage at the deceleration rate R2 should be started (step 8160). If the rotation angle of the rotary table 24 has not reached the R2 start angle, the process returns to step 8150, and if it is determined that the R2 start angle has been reached, the process proceeds to the next step.

In the following steps, the above step 813
0 to 8160, deceleration at the deceleration rate R2 (step 8
170), it is determined that the rotation speed = C5 (step 818)
0), the rotation speed = C5 is maintained (step 8190), it is determined whether the rotation angle at which the acceleration at the deceleration rate R3 is to be started is reached (step 8200), and the control of the deceleration (step 8210) is performed at the deceleration rate R3. You.

Following these executions, the control unit 50
Determines whether the rotation angle of the rotary table 24 has reached the rotation angle at which the rotation should be stopped, that is, the end point (step 8220). At this time, if the detected rotation angle of the rotary table 24 and the rotation angle of the set end point are within the range of a preset allowable error, it is determined that the rotation angle of the rotary table 24 has reached the end point. You. If it is determined that the end point has not been reached, the process returns to step 8210. When determining that the rotation angle of the rotary table 24 has reached the end point, the control unit 50 instructs the servomotor 36 to stop rotating (step 8230). With the stop of the servo motor 36, the rotary table 2
The rotation of 4 stops.

As described above, in the vertical rotary injection molding machine 10 of this embodiment, the rotary table 24 having a large moment of inertia is accelerated in a plurality of acceleration stages to quickly reach the maximum speed, and a plurality of deceleration stages. To quickly decelerate from the maximum speed and stop accurately. For this reason, the acceleration and deceleration of the rotary table 24 becomes smooth, and the rotary table 24 quickly reaches the maximum rotation speed and can be accurately stopped at the set rotation position. In addition, when the rotary table 24 is stopped, a slight swing does not occur. Further, an excessive load is not applied to the servo motor 36 and the like constituting the rotary drive unit 28 during acceleration and deceleration.

Thus, the pattern 7 routine is terminated and the program returns to the main routine. Upon returning to the main routine, the pattern 8 routine is subsequently executed. Since the control processing in the pattern 8 routine is different from the pattern 7 only in the rotation direction of the rotary table 24, the detailed description of the pattern 8 is omitted. Also, the control processing in patterns 1 to 6 when another mode is selected is different from the above-described pattern 7 only in the start point-end point angle and the rotation direction of the rotary table 24. Omitted.

When the rotary table 24 is stopped at a set rotation position, for example, at a position rotated by 180 ° from the reference position, the positioning pin 80 of the positioning mechanism 82 is driven in a direction of descending along the direction of arrow D in FIG. Is done.
As a result, the tip of the positioning pin 80 is positioned at the positioning hole 90b
, The relative rotation position between the movable platen 22 and the rotary table 24 is fixed. The rotary table 2 with the positioning pins 80 fitted in the positioning holes 90b
The relative position of 4 is set such that the upper dies 26a and 26b installed on the rotary table 24 exactly face the lower dies 16a and 16b installed on the fixed platen 14. Therefore, the mold clamping cylinders 34a, 34b
When the movable platen 22 and the rotary table 24 are lowered in the direction toward the fixed platen 14 by driving the mold clamping piston rods 30a and 30b, the upper dies 26a and 26b mounted on the rotary table 24 and the fixed platen 14 By properly joining the installed lower dies 16a and 16b, proper mold closing and mold clamping are realized.

Acceleration of the rotary table 24 to the maximum rotation speed and deceleration from the maximum rotation speed are performed quickly and stopped accurately. Further, after the stop, the relative position of the movable platen 22 is accurately fixed by the positioning mechanism 82 and the positioning holes 90a and 90b. For this reason, the upper dies 26a and 26b and the lower
The exchange of the relative positions with the a and 16b is performed quickly and accurately. Therefore, the time required for one cycle of injection molding can be shortened to realize a cycle-up, and the quality of a molded product can be improved by accurate mold closing and mold clamping.

On the other hand, when the rotary table 24 is driven to rotate and the normal stop is not performed, and the rotary table 24 may pass through the set stop position, the buffer mechanism 62a provided on the movable platen 22 may be used. 62b hydraulic piston 60,
Overhang member 6 formed on rotary table 24
The rotation of the rotary table 24 can be stopped by the contact of the contact portions 64a, 64b of 6a, 66b. At this time, the hydraulic piston 60 of the buffer mechanism 62a, 62b
A pressing force corresponding to the contact between 4a and 64b is exerted. However, the hydraulic oil in the hydraulic cylinder 58 and the relief circuit 68 communicating with the hydraulic cylinder 58 is discharged through the relief valve 78 while being balanced with the pressing force. Therefore, the impact caused by the contact between the hydraulic piston 60 and the contact portions 64a and 64b is reduced, and the rotation of the rotary table 24 is stopped rapidly and without any impact. Therefore, even if the rotary table 24 is not normally stopped for some reason,
The rotary table 24 can be safely stopped without damaging the rotary table 24 and other components.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the present embodiment, the encoder 48 attached to the servomotor 36 is used to detect the rotational position of the rotary table 24.
In addition to the encoder 8, an encoder or the like dedicated to detecting the rotational position of the rotary table 24 may be provided. Further, a position sensor for detecting that the rotary table 24 is at the reference position or the set rotation position may be provided. A configuration is also possible in which this position sensor is used as a reset switch for detecting the rotational position by the encoder 48.

Further, in the present embodiment, the contact portions 64a and 64b are arranged at an angle of 60 ° so as to correspond to the case where the set rotation range of the rotary table 24 is 180 °. By removing one of the contact portions 64a or the contact portion 64b, the set rotation range of the rotary table 24 is 240 °.
Can be handled. Alternatively, by adjusting the installation position of the contact portion in various ways, the rotary table 24 can be adjusted.
Can be adapted to various set rotation ranges.

[0045]

As described above, according to the vertical rotary injection molding machine of the present invention, the rotary table is rapidly accelerated to the maximum rotation speed, and then quickly decelerated from the maximum rotation speed to accurately stop. Therefore, the cycle of injection molding can be improved. Moreover, accurate mold closing and mold clamping are possible.

[Brief description of the drawings]

FIG. 1 is a front view showing a schematic configuration of a vertical rotary injection molding machine according to an embodiment.

FIG. 2 is a partial cross-sectional view of the vicinity of a rotary drive unit, a movable platen, and a rotary table of the vertical rotary injection molding machine according to the embodiment.

FIG. 3 is a plan view of a movable platen and a rotary table of the vertical rotary injection molding machine according to the embodiment.

FIG. 4 is a partial cross-sectional view of a positioning mechanism of the vertical rotary injection molding machine according to the embodiment.

FIG. 5 is an explanatory view of a buffer mechanism of the vertical rotary injection molding machine of the embodiment.

FIG. 6 is an explanatory diagram of a control unit of the vertical rotary injection molding machine of the embodiment.

FIG. 7 is an explanatory diagram of a rotation mode of a rotary table in the vertical rotary injection molding machine of the embodiment.

FIG. 8 is an explanatory diagram of an acceleration / deceleration model during rotation of a rotary table in the vertical rotary injection molding machine of the embodiment.

FIG. 9 is a flowchart of control of acceleration / deceleration of a rotary table by a control unit in the vertical rotary injection molding machine of the embodiment.

FIG. 10 is a flowchart of a rotary table acceleration / deceleration control by a control unit in the vertical rotary injection molding machine of the embodiment.

FIG. 11 is an exemplary view of a configuration of a vertical rotary injection molding machine of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Vertical rotary injection molding machine, 14 ... Fixed board, 16a, 16B ... Lower mold, 22 ... Movable board, 2
4 rotary table, 26a, 26B upper mold, 27 molding die, 28 rotation drive unit, 30
a: mold clamping piston, 34a: mold clamping cylinder, 3
6 ... servo motor, 46 ... shaft, 48 ...
-Encoder, 50 ... Control unit, 62a, 62
b: buffer mechanism, 64a, 64b: contact part, 66
a, 66b: projecting member, 68: relief circuit, 78: relief valve, 80: positioning pin, 82: positioning mechanism, 90a, 90b: positioning hole.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 45/00-45/24 B29C 45/76

Claims (4)

(57) [Claims] 1. A fixed plate arranged along a horizontal direction, a movable plate installed facing the fixed plate and movable up and down to change a relative position with respect to the fixed plate, and a movable plate. An up-down drive mechanism for driving in the up-down direction, a rotary table arranged on the lower surface of the movable plate so as to be movable up and down together with the movable plate, and capable of rotating forward and reverse along the circumferential direction, and driving the rotary table forward and reverse. Servo motor driving mechanism, comprising a rotation angle detecting means for detecting a rotation angle from a set reference position of the rotary table, a plurality of lower dies installed on the fixed platen and facing the lower die, In a vertical rotary injection molding machine capable of simultaneously pressing a plurality of sets of dies including a plurality of upper dies installed on a rotary table at a plurality of rotation positions of the rotary table, the servo motor drive mechanism includes: Addition At times, the rotary table is accelerated to a predetermined rotation speed by an acceleration step including a plurality of acceleration stages and a constant speed stage set at least once between the plurality of acceleration stages according to the rotation angle of the rotary table. When decelerating, the rotary table is decelerated and stopped by a deceleration step including a plurality of deceleration stages and a constant speed stage set at least once between the plurality of deceleration stages according to the rotation angle of the rotary table. A vertical rotary injection molding machine characterized in that: 2. A positioning pin installed on the movable plate and reciprocating along the axial direction of the movable plate, and the positioning pin is disposed on the rotary table in accordance with the plurality of rotational positions of the rotary table, and the positioning pin can be fitted therein. 2. The vertical rotary injection molding machine according to claim 1, further comprising a positioning hole. 3. The movable plate is provided with a buffer mechanism having a hydraulic cylinder and a hydraulic piston having an axis along a rotation tangential direction of the rotary table, and the rotary table is provided along an axial direction of the hydraulic piston. 3. The vertical rotary injection molding machine according to claim 1, further comprising a contact portion capable of contacting the hydraulic piston. 4. A shaft which is coaxially connected to the rotary table and is provided on the rotary table; and a shaft side gear of a spur gear which is coaxially connected to the shaft and the shaft; 4. A spur gear driving side gear which is meshed with a shaft side gear so as to be variable in relative position along an axial direction and is rotationally driven by a driving source is provided. Vertical rotary injection molding machine.