JPH0569693B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an injection molding machine for threaded molded products such as plastic screw caps, which are often used for caps of various bottles, etc. Specifically, two independent fixed molds with thread forming parts are placed on a rotary table, and while molding is being performed with one fixed mold and movable mold, the other fixed mold is This invention relates to an injection molding machine for molded products with threads, in which the molded products are released from the mold using a dedicated screw removal mold release device.

[Conventional technology]

In general injection molding machines for threaded molded products, a thread forming part (thread forming core) is provided on the movable mold side, and when the mold is opened, the thread forming part is rotated to release the molded product. ing. However, in conventional injection molding machines for threaded molded products with such a configuration, the thread forming part must be rotatably installed in the mold, and the molded product must be pressed in the axial direction during mold release. There is a problem in that a moving mechanism is required, which complicates the mold structure. Furthermore, since a rotary screw removal process is required, the mold opening speed decreases, and the injection molding time for one cycle increases, resulting in poor operational efficiency. In addition, since it is necessary to rotate the thread forming part (thread forming core), an inner gate cannot be used, and there is also the problem that gate marks remain on the outer surface of the molded product.

In view of this point, two independent fixed molds with thread forming parts are arranged on the rotary table, and while molding is being performed with one fixed mold and the movable mold,
An injection molding machine for threaded molded products, in which the molded product on the other stationary mold is released from the mold by a dedicated screw removal device, has been proposed in Japanese Patent Laid-Open No. 60-247519.

FIG. 12 is a diagram showing a schematic configuration of the above-mentioned prior application. In the figure, 101 and 102 are boards connected by tie bars 103, one of which is 101 and 102.
A rotary table 105 is installed which is intermittently rotated every 180 degrees by a drive device 104. Two fixed molds 106 are placed on the rotary table 105.
are mounted at intervals of 180 degrees, and a movable mold 108 on a movable plate 107 and a screw removal device 109 are positioned opposite each other at rotation stop positions of the two fixed molds 106. In addition, a thread forming part (thread forming core) is formed on the fixed mold 106 side, and an outer surface forming part of the molded product is formed on the movable mold 108 side, so that the rotational movement of the thread forming core is performed when the mold is opened. Fixed mold 10 without accompanying
The mold opening is completed with the molded product 110 still attached to the 6 side. While molding is being performed with one fixed mold 106 and movable mold 108, the molded product 1 adhered to the other fixed mold 106
10 is removed from the mold by a screw removal device 109. Therefore, according to this prior application, it is possible to improve the operating efficiency without causing a decrease in the mold opening speed of the mold, and also because it is possible to use an inner gate, there is no need to leave gate marks on the outer surface of the molded product 110. It becomes something that does not exist.

[Problem to be solved by the invention]

However, in the above-mentioned prior application, since the rotation range of the rotary table 105 is limited to the space surrounded by the plurality of tie bars 103, the rotary table 105 cannot be increased in size. The size of the fixed mold 106 to be mounted is limited, and it has been difficult to mount large molds for multiple molds. Further, the screw removal device 109 is also located in a space surrounded by a plurality of tie bars 103, and there is also the problem that it is difficult to take out the molded product 110 from the device body.

The present invention has been made in view of the above points, and its purpose is to make it possible to increase the size of a rotary table, thereby realizing an increase in the size of a mold in which the rotary table is mounted, and to improve the device for molded products. An object of the present invention is to provide an injection molding machine for a threaded molded product that can be easily taken out of the main body and that allows easy visual confirmation of the screw removal operation.

[Means to solve the problem]

The above-mentioned object of the present invention is to provide a fixed platen, a plurality of tie bars having one end fixed to the fixed platen, a movable platen attached to be slidable on the group of tie bars, and a movable platen attached to the fixed platen so as to be slidable on the group of tie bars. A rotary table rotatably held in close proximity, two fixed molds mounted at symmetrical positions on the rotary table and each provided with a thread forming part for the molded product, and rotation of the two fixed molds stopped. a movable mold on the movable platen facing the one fixed mold in position;
In an injection molding machine for a threaded molded product, which is provided with a screw removal device that faces the other fixed mold at a rotation stop position of one fixed mold, the tie bar group is connected to the first It has a three-piece structure consisting of a second and third tie bar, and the second and third tie bars are respectively arranged at the top and bottom positions on the far side when viewed from the operator operation side of the injection molding machine, and the second and third tie bars are respectively placed at the top and bottom positions on the rear side when viewed from the operator operation side. A first tie bar is disposed on the side and at a height position intermediate between the second and third tie bars, the first tie bar is the rotation center of the rotary table, and the screw removing and releasing device is arranged, This is achieved by configuring the tie bar to be located on the front side of the first tie bar when viewed from the operator operation side.

[Effect]

As mentioned above, since the first tie bar on the front side when viewed from the operator operation side is the rotation center of the rotary table, the radius of the rotary table must be large enough to correspond to the area defined by the three tie bars. It is possible to increase the size of the two fixed molds mounted on this rotary table, and since the tie bar serves as the rotation axis of the rotary table, the number of parts can be reduced. In addition, since the screw removing mold release device is located on the front side of the first tie bar, it is possible to take out the molded product from the screw removing mold release device to the outside of the device main body, and to visually check the screw removing mold release operation. becomes easier.

〔Example〕

The present invention will be explained below with reference to one embodiment shown in FIGS. 1 to 11. Figure 1 is a side view of the main parts showing the arrangement relationship between tie bars and rotary tables, Figure 2 is a plan view showing the overall configuration of an injection molding machine for threaded molded products, and Figure 3 is a front view showing the overall configuration. It is. First, the overall configuration will be explained with reference to FIGS. 2 and 3.

In Figures 2 and 3, the reference numeral 1 generally indicates an injection molding machine, including an injection device 2, a mold clamping device 3, a screw removal device 4, and a control device (not shown) that controls the entire system. It is mainly composed of. The injection device 2 has a built-in screw for kneading and plasticizing the resin, a heating cylinder 5 having a nozzle 6 at the tip for pouring out the molten resin, a hopper 7 for supplying the resin material to the screw, and a screw rotation. and a drive source 8 for injection.

Further, the mold clamping device 3 includes a machine frame 25
A fixed platen 9 has one end of three tie bars 10, 11, and 12 fixed thereon as will be described later, and a movable platen 13 has a movable mold 14 mounted thereon and is slidably installed on the tie bar group. , a mold clamping mechanism 15 consisting of a toggle link mechanism or the like for driving the movable platen 13, a support plate (not shown) to which the other end of the tie bar group is attached, a mold clamping drive cylinder 16, etc.,
Furthermore, it is equipped with a rotary table 17 on which two fixed molds 18 are mounted.

Further, as will be described later, the screw removal device 4 is disposed at a position facing one of the fixed molds 18 on the rotary table 17, which is driven to rotate intermittently every 180 degrees, and the screw removal device 4 is driven Head 19 is the third
As shown in the figure, it is arranged so that it can move linearly back and forth, and can freely rotate downward by 90 degrees at the complete retraction position. Furthermore, a belt conveyor 21 that is moved up and down by an elevating device 20 is attached below the screw removing device 4, and the molded products extracted by the screw removing device 4 are arranged on the belt conveyor 21. It is now being placed on the site. A surveillance camera 22 is installed to check whether all molded products are placed on the belt conveyor 21. Note that each of these devices and members 4, 20, 21, and 22 is located on the operator operation side (on the front side of the paper in FIG. 3).

Note that here, 23 is a drive cylinder for separating the core mold 32 of the fixed mold 18 from the mounting mold 31, which is activated at a timing to be described later, and 24 is a sprue runner for a molded product, which is also activated at a timing to be described later. It is a device.

As shown in FIG. 1, the base material 25 of the device body
The fixed platen 9 fixed above has the three tie bars 10, 11, 12, that is, the first tie bar 10, the second tie bar 11, and the third tie bar.
One end of the tie bar 12 is fixed. Second and third tie bars 11 and 12 are arranged at the upper and lower corners of the rear side of the fixed platen 9 when viewed from the operator operation side, and second and third tie bars 11 and 12 are arranged at the front side of the fixed platen 9 when viewed from the operator operation side. , third tie bar 1
The first tie bar 10 is located at a height between 1 and 12.

The rotary table 17 is pivotally supported on the first tie bar 10 with the first tie bar 10 as the center of rotation, and its radius R is from the center of the first tie bar 10 to the second tie bar 11 or Third
The dimension is set to be slightly smaller than the distance to the outer diameter surface of the tie bar 12. Therefore, the rotary table 17 is considerably larger than that shown in the earlier application mentioned above, and a large fixed mold 18 suitable for molding multiple pieces can be attached thereto.

FIG. 4 is a sectional plan view of a main part showing the rotational drive mechanism of the rotary table 17. In the same figure, 2
Reference numeral 6 denotes a bearing body that supports the rotary table 17 and rotates integrally therewith, and is mounted on the first tie bar 10. 27 is a gear that rotates integrally with the bearing body 26; 28 is a hydraulic motor for rotating the table that is attached to the fixed platen 9 via a support piece 29; and a gear 30 that is attached to the output shaft of the motor 28;
is in mesh with the gear 27 mentioned above. Therefore, the rotation of the hydraulic motor 28 rotates the rotary table 17 via the gears 30, 27 and the bearing body 26. In this embodiment, the rotary table 17 is intermittently rotated every 180 degrees, but it is optional whether the rotary table 17 is always rotated in the same direction or reciprocated.

When the rotary table 17 described above is driven to rotate,
Although not shown, for example, by driving the bearing body 26 in the axial direction with an appropriate driving means, the rotary table 17 is rotated with a slight distance from the fixed platen 9. This is designed to ensure smooth rotation of the rotary table 17. Therefore, in this embodiment, the gear 27 and the bearing body 26 are connected by a spline shaft.

On the rotary table 17, the two fixed molds 18 are mounted in symmetrical positions by appropriate means, and in this embodiment, each fixed mold 18 has two
It is said to be a multi-cavity mold that can mold a total of 8 molded products (x4). Furthermore, each fixed mold 18 includes a mounting mold 31 that is fixed to the rotary table 17, and a core mold 32 that can be separated from the mounting mold 31 by a predetermined amount.
Eight screw forming cores 33 are formed in the core mold 32, and a sprue 34, a runner 35, and a gate 36 are provided in the mounting mold 31 and the core mold 32.

Two fixed molds 1 in the rotation stop position as shown in Fig. 4
Among the fixed molds 8 and 18, the fixed mold 18 on the far side (the upper side in FIG. 4) when viewed from the operator operation side is attached to the movable platen 13 that can freely slide on the tie bars 10 to 12 groups, as described above. The movable molds 14 are arranged facing each other, and in the mold clamping state, as shown by the two-dot chain line in the figure, the movable molds 14
A cavity 37 is formed with the fixed mold 18. In addition, in Fig. 4, 9a, 17
a is an opening provided in the stationary platen 9 and the rotary table 17 for inserting the nozzle 6.

Furthermore, among the two fixed molds 18, 18 at the rotation stop position in FIG. 4, the fixed mold 18 on the near side (lower side in FIG. 4) when viewed from the operator operation side has the following: Drive heads 19 of the screw removing and releasing device 4 are arranged opposite to each other, and the configuration of this screw removing and releasing device 4 will be explained next.

FIG. 5 is a front view of the screw removal device 4.
In the figure, reference numeral 40 denotes a fixed frame with open upper and lower surfaces fixed to the left side of the machine frame 25 on the operator's side, and a head linear transfer cylinder 41 is fixed onto the fixed frame 40 via an appropriate support member. A support frame 43 is attached to a piston rod 42 of the head linear transfer cylinder (for example, a hydraulic cylinder) 41. Therefore, by the operation of the piston rod 42 of the head linear transfer cylinder 41, the drive head 19 is moved to the head rotation cylinder 47.
At the same time, it is designed to be linearly transferred back and forth from side to side as shown in the figure. Further, on the support frame 43 is a holding frame 45 for the gear box 44 of the drive head 19 described above.
is rotatably mounted around a support shaft 46, and a head rotation cylinder (for example, a hydraulic cylinder) 47 is pivotally connected to the support frame 43 by a support shaft 43a. Further, the piston rod 48 of the head rotation cylinder 47 is equipped with the holding frame 4 on which the gear box 44 is mounted and fixed.
The drive head 19 is reciprocated by 90 degrees with the support shaft 46 as a rotation fulcrum by the operation of the piston rod 48 of the head rotation cylinder 47. ing.

On the right side of the holding portion 44a of the gearbox 44 in the drawing, 2×4 chucking means 50 are arranged, and on the left side of the gearbox 44 there is provided a chucking means 50 for simultaneously rotating the eight chucking means 50. A chuck rotation motor 51 (for example, an electric motor) is attached. Then, at the tip of each of the chucking means 50, after molding and opening the mold at the timing described later, the rotary table 17 is rotated 180 degrees to coat the screw forming core 33 of the fixed mold 18. The molded products are arranged to face each other, and as will be described in detail later, the entire drive head 19 is advanced by the head linear transfer cylinder 41, and the tip of each chucking means 50 chucks the molded products. I'm starting to do that. In FIG. 5, reference numeral 49 denotes a cable containing electric wires and air tubes for supplying motor drive current to the drive head 19 and air for chuck control, which will be described later.

6 and 7 show the gearbox 44.
FIG. 6 is a layout explanatory diagram as viewed from the front and side to respectively show the rotation transmission system inside. As shown in each figure, the output shaft 51 of the chuck rotation motor 51
Two first intermediate gears 53, 53 are meshed with an output gear 52 fixed to a. The first intermediate gears 53, 53 are fixed to one end side of two rotating shafts 54, 54 which are pivotally supported by the gear box 44, and the second intermediate gears 55, 53 are fixed to the other end side of each rotating shaft 54, respectively. 55 are fixed respectively. Four driven gears 56 of the chucking means 50 are meshed with each of the second intermediate gears 55, so that the rotation of a single chuck rotation motor 51 can drive eight driven gears. 55 (chucking means 50) are synchronously rotated in the same direction. In addition, in Figure 6, 5
Reference numeral 7 denotes a rotary joint provided on the rear end side of each chucking means 50, and an air tube (not shown) is connected to the rotary joint 57.

FIG. 8 is a sectional view showing details of the chucking means 50. In the figure, reference numeral 58 denotes a bearing attached to the gear box 44, and the rotating body 5 with which the driven gear 56 is integrally formed.
The sleeve portion 59a of No. 9 is rotatably held. Reference numeral 60 denotes a ball spline body that is fitted and fixed to the rotating body 59, and is spline-coupled to a drive shaft 61 inserted through the ball spline body. That is, the drive shaft 61 rotates integrally with the ball spline body 60 (driven gear 56), but is configured to be able to slide a predetermined amount in the axial direction with respect to the ball spline body 60. The rotary joint 57 is attached to the end.

Reference numeral 62 denotes a sleeve body fixed to the distal end side of the drive shaft 61, and a chuck body 63 is screwed and fixed to the sleeve body 62. 63a is a cylindrical recess formed on the tip side of the chuck main body 63, and a bladder 64 made of an elastically deformable material is attached within the recess 63a.
The molded product is held (chucked) by this bladder 64 as will be described later.

65 is the sleeve portion 59a of the rotating body 59
A coil spring is installed inside, and one end of it is connected to the rotating body 5.
The other end of the protrusion 59b provided on the inner circumference of the sleeve body 62 is in elastic contact with the rear end surface of the sleeve body 62,
The sleeve body 62 and the members 57, 61, 63, and 64 integrally connected thereto are pressed rightward in the figure.

Reference numeral 66 denotes an air chamber formed between the wall surface of the recess 63a and the bladder 64, which connects the air passage (not shown) in the rotary joint 57 and the drive shaft 61.
The chuck body 63 communicates through an air passage 61a inside the chuck body 63 and air passages 63b and 63c in the chuck body 63. Then, by sending air into the air chamber 66, the bladder 64 swells inward, thereby reliably chucking the outer peripheral surface of the molded product adhered to the thread forming core 33 of the fixed mold 18, as will be described later. Molded products are now released from the mold by removing screws.

FIG. 9 is a sectional view of a main part showing the peripheral portion of the bladder 64 in detail. As shown in the figure, the bladder 64 has a substantially cup-like shape, and has a bottom portion 64a.
, a cylindrical portion 64b, and a flange end portion 64c, and in this embodiment, it is integrally formed of a soft urethane material. The bottom part 6
A center hole 64a-1 is bored in 4a, and an annular projection 64a-2 facing outward is formed around the center hole 64a-1. Then, with the annular projection 64a-2 in close contact with the bottom surface of the recess 63a of the chuck body 63, the washer 67 is
By screwing and fastening the mounting screw 68 to the chuck body 63 through the
4a is attached to the bottom surface of the recess 63a of the chuck body 63. Further, the flange portion 64c
The chuck body 63 is secured to the chuck body 63 by a cap 70 which is screwed and fastened to a threaded portion 63d on the outer peripheral surface of the tip of the chuck body 63 via an annular retainer 69.
It is attached closely to the tip surface of the

In the bladder 64 mounted as described above, the cylindrical portion 63b, which has an outer diameter smaller than the inner diameter of the recess 63a of the chuck body 63, is elastically deformable. Then, by feeding air into the air chamber 66, the cylindrical portion 63b expands inward,
As shown by the two-dot chain line in FIG. 9, the outer periphery of the molded product 71 attached to the thread forming core 33 is tightly held and molded against the biting force of the resin to the thread forming core 33. The product 71 can be forcibly rotated in the screw removal direction.

In this embodiment, which uses the chucking mechanism using the bladder 64, since the bladder 64 is made of a soft material, there is no risk of damaging the outer surface of the molded product 71, and a high-quality molded product can be obtained. It has the great advantage of being able to provide In addition, bladder 64
The material is not limited to soft urethane, but may be any soft, flexible, and durable material.

The driving head 19, which is equipped with the chucking means 50 having the above-described configuration, is configured such that when the rotary table 17 rotates and one of the stationary molds 18, to which the molded product 71 is attached, faces the driving head 19, The head is advanced by the cylinder 41 for linear transfer, and the molded product 71 is stored in the bladder 64 of each chucking means 50. Thereafter, air is fed into the air chamber 66, and the bladder 64 chucks the molded product 71 as described above. Next, when the chuck rotation motor 51 is driven, the driven gear 56 is
A rotary body 59 having a rotor is driven to rotate, and a chuck body 63 and a bladder 64 are rotated via a ball spline body 60, a drive shaft 61, and a sleeve body 62.

By this rotation of the bladder 64, the molded product 71 is unscrewed from the thread forming core 33 of the fixed mold 18, but the screw is removed by an amount corresponding to one thread pitch per one rotation of the bladder 64. The entire drive head 19 is connected to the head linear transfer cylinder 41.
will be retreated. At this time, as described above, the members of each chucking means 50, such as the sleeve body 62, the chuck body 63, and the bladder 64, which are integrally connected to the drive shaft 61, maintain their positions unchanged with respect to the gearbox 44. Since it is slidable relative to the body 59 and the ball spline body 60 and is constantly pressed in the distal direction (toward the molded product 71) by the coil spring 65, the amount of screw removal due to the rotation of the bladder 64 can be reduced. However, even if the retraction speed of the drive head 19 is not precisely adjusted, the bladder 64 can be smoothly retracted. Furthermore, since the amount of rotational retraction of the bladder 64 is self-adjusted in relation to the amount of retraction of the drive head 19 in this way, even if there is some rotational variation among the many chucking means 50, the bladder of each chucking means 50 is All in all, the screw removal operation is performed reliably, and this effect is great in the case of a multi-cavity screw removal mold release device.

Fladder 64 of each chucking means 50 described above
The molded product 71 attached to the thread forming core 33 of the fixed mold 18 is removed from the mold by the rotation of the molded product 18 and the retreat of the drive head 19, and the molded product 71 is completely pulled out to the bladder 64 side. At this point, the rotation of the chuck rotation motor 51 is stopped. Also,
The head linear transfer cylinder 41 further moves the drive head 1 after the chuck rotation motor 51 has stopped.
9 is retracted, and when the drive head 19 reaches a predetermined retracted position (the position shown by the two-dot chain line in FIG. 5), the retraction of the drive head 19 is stopped.

When the retreat of the drive head 19 is stopped, the belt conveyor 21 is raised from the lowered position by the lifting device 20, and the drive head 19 is rotated by 90 degrees by the head rotation cylinder 47. The molded product 71 chucked into each bladder 64 is placed facing downward on the belt conveyor 21.
position above. After that, the air in the air chamber 66 of each drive head 19 is sucked into each bladder 64.
The chuck of the molded products 71 is released, and the molded products 71 are aligned and placed on the belt conveyor 21. Subsequently, when the belt conveyor 21 is lowered and the molded product 71 on the belt conveyor 21 has retreated from the rotation locus of the drive head 19, the drive head 19 is rotated by 90 degrees by the head rotation cylinder 47. It is then moved back to its original position, ready for the next unscrewing and demolding cycle.

In this way, the drive head 19 is rotated 90 degrees to transfer the molded product 71 onto the belt conveyor 21 with a soft touch, and the molded product 71 is transferred onto the belt conveyor 2.
1, the molded product 71
There is no risk of the molded product 71 being damaged by falling or the like, and the molded product 71 transported by the belt conveyor 21 can be easily processed in the next process. Furthermore, the alignment state of the molded products 71 on the belt conveyor 21 is pattern recognized by a monitoring system using the monitoring camera 22,
It also becomes easier to build an automatic monitoring system.

FIG. 10 is a schematic configuration diagram for explaining the overall operation of the injection molding machine for screw removal molding according to this embodiment, and FIG. 11 is an explanatory diagram showing the operation cycle, which is generally clear from the above explanation. In Although,
Next, the overall operation will be explained with reference to the same figures.

In FIG. 11, T1 represents the initial time point of one cycle in the continuous molding/screw removal mold release cycle. The mold 18 is in a state where the molded product 71 and the unnecessary part 75 of the sprue runner part are integrated, and the mounting mold 3 of the fixed mold 18
1 and the core mold 32 are spaced apart from each other and face the drive head 19, and the other mold 18 on the rotary table 17 has a molded product 71 covered on its thread forming core 33. With the mounting mold 31 and core mold 32 in close contact with each other, the movable platen 13
It faces the upper movable mold 14. Also, the 10th
As shown in the figure, it also faces a spacing device 72 operated by the drive cylinder 23 attached to the stationary platen 9. Furthermore, the initial time T1
, the rotary table 17 is moved from a table lift position slightly spaced from the fixed platen 9 to the fixed platen 9.
transition to a table-down position in close proximity to the
The positioning mechanism using a positioning pin (not shown) between the stationary platen 6 and the rotary table 17 shifts to a positioning state.

A rotary table 17 facing the movable mold 14
On the upper fixed mold 18 side, in other words, on the molding mold side, after the initial time T1, the movable platen 13 is first moved by the mold clamping drive cylinder 16.
is driven, and the movable mold 14 on the movable platen 13 is moved from the mold opening position in the direction of arrow A in FIG. 10 and brought to the mold clamping state shown in the same figure. Subsequently, the injection device 2 is advanced in the direction of arrow C in FIG.
is touched to the resin injection port 73 of the fixed mold 18,
Molten resin is injected into the mold by advancing the screw 74 within the heating cylinder 5, and following the injection stroke, the pressure of the injected resin is held.

After the above-mentioned pressure holding process is completed, the positioning mechanism using the positioning pin (not shown) between the stationary platen 9 and the rotary table 17 shifts to the positioning release state, and the resin injected into the mold enters a cooling period until the mold opening start point, which will be described later. On the other hand, after the pressure holding stroke is completed, the screw 74 in the heating cylinder 5 is rotated, and as is known in the art, the resin material supplied from the hopper 7 is kneaded and plasticized and fed to the tip side of the screw 74. Along with this, the screw 74 retreats and the molten resin necessary for the next shot is transferred to the screw 74.
After charging is completed, the heating cylinder 5 and the like are moved back in the direction of arrow D in FIG. 10, and the injection device 2 is prepared for the next shot.

After that, when the timer for setting the cooling period expires, the movable mold 14 is driven in the direction of arrow B in FIG. 10 to open the mold, and the molded product is placed on the screw forming core 33 of the fixed mold 18. 71 is left attached. Furthermore, at the start of this mold opening, the rotary table 17 is brought from a state in close contact with the fixed platen 17 to a table lift position slightly separated from the fixed platen 9, and the rotary table 17 is brought to a table lift position slightly separated from the fixed platen 9. Thereafter, at a predetermined timing, the rotary table 17 is rotated 180 degrees by the motor 28 to reach the initial time T2 of the next cycle.

(Note that the rotation speed of the rotary table 17 is reduced at the end of its rotation.) On the other hand, on the other fixed mold 18 side on the rotary table 17 facing the drive head 19, After the initial time T1 described above, first, the driving cylinder 23 causes the separating device 72 to
In FIG. 10, the core mold 32 is separated from the mounting mold 31 by being driven in the direction of arrow E, forming a parting space in the fixed mold for taking out the sprue runner, and pulling out the solidified resin from the sprue 34. The sprue runner portion 75 is attached to the core mold 32 side as shown in Figure 10. Subsequently, the sprue runner removal device 24 shown in FIG. 3 is operated to cut the sprue runner portion 75 at the gate 36 portion (the minimum diameter portion where the runner communicates with the cavity) and pull it out from the core mold 32. , discharged outside the device.

After the above-described ejection stroke of the core mold 32, the drive head 19 is advanced in the direction of arrow G in FIG. The molded product 71 attached to the thread forming core 33 of the core mold 32 is housed in the bladder 64 . (Note that at the end of the forward movement of the drive head 19, the forward speed is reduced.) Subsequently, air is fed into each chucking means 50 as described above, and the molded product 71 is chucked by the bladder 64. It can be done.

After the chucking process described above is completed, the chuck rotation motor 51 moves the bladder 64 to the first position.
The drive head 19 is rotated in the direction of the arrow I in FIG. 10, and the drive head 19 is rotated in the direction of the arrow I in FIG. The molded product 71 is retracted in the direction of the arrow H, and thereby the molded product 71 is removed from the thread forming core 33 and released from the mold, as described above. The retraction speed of the drive head 19 is set to be low at the beginning of its retraction.

When the molded product 71 held by the bladder 64 is completely removed from the fixed mold 18 side by the rotation of the bladder 64 and the retreat of the drive head 19, the rotation of the chuck rotation motor 51 is stopped, and this After the rotation of the bladder 64 has been stopped and the drive head 19 has retreated to a predetermined position, the retreat of the drive head 19 by the head linear transfer cylinder 41 is subsequently stopped.

When the retraction of the drive head 19 is stopped, the belt conveyor 21 is moved by the lifting device 20.
It is lifted up from the lowered position to the raised position (first
0), and the drive head 19 is rotated (reversed) by 90 degrees in the direction of arrow J in FIG. 10 by the head rotation cylinder 47. At the end of the rotation of the drive head 19, as shown by the two-dot chain line in FIG.
In this state, the air pressure chucking by the chucking means 50 including the bladder 64 is released, and the molded product 71
are aligned on the belt conveyor 21 with a soft touch.
It will be placed.

Subsequently, after a predetermined waiting time, the belt conveyor 21 is lowered in the direction of arrow M in FIG.
After retracting from the rotational trajectory of the drive head 19
is rotated 90 degrees (backward rotation) in the direction of arrow K in FIG. 10 by the head rotation cylinder 47. When the return rotation of the drive head 19 is completed, the removal of the molded product 71 is confirmed by the monitoring camera 22, and
After that, the molded product 71 is conveyed by the belt conveyor 21.
is conveyed in the direction of arrow N in FIG. After the drive head 19 is rotated back, the drive cylinder 23 moves the spacing device 72 back in the direction of arrow F in FIG.
After a predetermined waiting time, the cycle reaches the initial time point T2 of the next cycle. (Note that the return movement of the separating device 72 can be performed at any time after the driving head 19 is reversed.) Although the present invention has been described above with reference to an illustrated embodiment, it will be appreciated by those skilled in the art. Various modifications can be made without departing from the spirit of the present invention. For example, in addition to the bladder-type chuck described above, any chucking method such as a clamping tool using a spring can be adopted.

〔Effect of the invention〕

As described above, according to the present invention, a rotary table equipped with two fixed molds is provided, and a threaded molded product is molded using one fixed mold and a movable mold, while the other fixed mold is molded. In an injection molding machine for threaded molded products that can remove the screws from the molded product adhered to the mold, it is configured with three tie bars, with two tie bars located at the upper and lower positions at the rear when viewed from the operator operation side. Furthermore, another tie bar is disposed at an intermediate height position on the front side, and the tie bar on the front side as viewed from the operator operation side is set as the center of rotation of the rotary table. Therefore, the radius of the rotary table can be made large enough to match the area defined by the three tie bars, and the two fixed molds mounted on this rotary table can be made larger, making it possible to produce screw-molded products. It is suitable for machining a large number of pieces, etc., and productivity is improved. Furthermore, since the tie bar serves as the rotational support shaft of the rotary table, it also leads to a reduction in the number of parts. Furthermore, since the screw removal device is positioned closest to the operator's operation side, the mechanism for removing the molded product from the device body can be simplified, and the operator can easily visually confirm the screw removal operation. The injection molding machine for this type of threaded molded product has great industrial value.

[Brief explanation of the drawing]

1 to 11 relate to an injection molding machine for threaded molded products according to one embodiment of the present invention, FIG. 1 is a side view of main parts showing the arrangement relationship between the tie bar and the rotary table, and FIG. A plan view showing the overall configuration of the injection molding machine, Figure 3 is a front view showing the overall configuration of the injection molding machine, Figure 4 is a cross-sectional plan view of the main parts showing the rotation drive mechanism of the rotary table, and Figure 5 is a screw extractor. A front view of the mold release device, FIGS. 6 and 7 are explanatory diagrams of the arrangement as seen from the front and side to respectively show the rotation transmission system in the gear box of the drive head of the screw removal mold release device, and FIG. 8 is a drive diagram. 9 is a cross-sectional view of main parts showing in detail the peripheral portion of the bladder at the tip of the chucking means, FIG. 10 is an explanatory diagram of the operation, and FIG. 11 is an explanatory diagram showing the operation cycle, FIG. 12 is an explanatory diagram showing a schematic configuration of a conventional example. DESCRIPTION OF SYMBOLS 1... Injection molding machine, 2... Injection device, 3... Mold clamping device, 4... Screw removal mold release device, 5... Heating cylinder, 6... Nozzle, 7... Hopper, 8...
Drive source, 9... fixed plate, 10... first tie bar, 11... second tie bar, 12... third tie bar, 13... movable plate, 14... movable mold, 1
5...Mold clamping mechanism, 16...Mold clamping drive cylinder, 1
7... Rotating table, 18... Fixed mold, 19...
. . . Drive head, 20 . Gear, 28...Hydraulic motor for table rotation, 30
...Gear, 31...Mounted type, 32...Core type,
33... Core for thread formation, 34... Sprue, 3
5... Runner, 36... Gate, 37... Cavity, 40... Fixed frame, 41... Head linear transfer cylinder, 42... Piston rod, 43...
... Support frame, 44 ... Gearbox, 45 ... Holding frame, 46 ... Support shaft, 47 ... Head rotation cylinder, 48 ... Piston rod, 49 ... Cable, 50 ... Chucking means, 51 ... Chuck rotation motor, 52... Output gear, 53... First intermediate gear, 54... Rotating shaft, 55... Second intermediate gear, 56... Driven gear, 57... Rotary joint, 58... Bearing bearing, 59...Rotating body, 60...Ball spline body, 61...Drive shaft, 62...Sleeve body, 63...Chuck body, 64...Bladder, 65...Coil spring, 66
... Air chamber, 67 ... Washer, 68 ... Mounting screw, 69 ... Retainer, 70 ... Cap, 7
1... Molded product, 72... Separation device, 73... Resin injection port, 74... Screw, 75... Sprue runner part.

Claims (1)

[Scope of Claims] 1. A fixed platen, a plurality of tie bars having one end fixed to the fixed platen, a movable platen attached to be able to slide freely on the group of tie bars, and a movable platen adjacent to the fixed platen. a rotary table rotatably held at a position where the rotary table is rotated;
a movable mold on the movable platen that faces one of the fixed molds at a rotation stop position of the two fixed molds, and a movable mold on the movable platen that faces the other fixed mold at a rotation stop position of the two fixed molds. In an injection molding machine for threaded molded products, which is equipped with a mold and a screw removal device facing the mold, the tie bar group is composed of three tie bars consisting of first, second, and third tie bars, and the operator of the injection molding machine Second and third tie bars are arranged at upper and lower positions on the far side when viewed from the operator operation side, and a third tie bar is disposed at the front side and at a height intermediate between the second and third tie bars when viewed from the operator operation side. 1 tie bar is arranged,
The first tie bar is the center of rotation of the rotary table, and the screw removal device is located on the front side of the first tie bar when viewed from the operator operation side. Injection molding machine for molded products.