JP2768438B2 - Molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus for molding a resin product by filling a cavity formed between a pair of molds with a molten resin.
The present invention relates to a molding apparatus in which a molten resin supplied from a resin plasticizing means is temporarily stored in a resin reservoir and then filled in the cavity.

[0002]

2. Description of the Related Art Conventionally, the above-mentioned molding apparatus has been proposed in, for example, JP-A-6-254926. As shown in FIG. 1 and FIG.
A fixed mold 1 and a movable mold 2 forming a cavity C are provided, and a ring 3 is provided on the fixed mold 1 so as to be able to protrude and retract along the opening and closing direction of the mold.
The resin pool 3a is formed in a state where the resin pool 3a protrudes from the resin pool. Further, the fixed die 1 is provided with a hydraulic piston 5 which is connected to the ring 3 via a movable plate 4 integrally attached to the ring 3 and reciprocates the ring 3 in the above-described direction. . Further, the fixed mold 1 is formed with a runner 6 that penetrates the fixed mold 1 and opens to the center of the ring 3, and the molten resin supplied from a plasticizing means (not shown) is supplied to the inside of the ring 3. It is designed to be filled. Further, the movable plate 4 is integrally provided with a stopper 7 which is protruded and retracted from the fixed mold 1 together with the ring 3, and the movable mold 2 is brought into contact with the tip of the stopper 7 protruded from the fixed mold 1. Accordingly, the movable platen 2 and the ring 3 are located at the closest positions, and the resin reservoir 3a is formed.

[0005] The molding operation in the molding apparatus thus constructed is performed as follows. First, as shown in FIG. 1, the hydraulic piston 5 is operated,
After the ring 3 and the stopper 7 are projected from the fixed mold 1, the mold is clamped until the movable mold 2 comes into contact with the stopper 7. As a result, a resin reservoir 3a is formed between the movable mold 2 and the ring 3.

After the molten resin is filled into the resin reservoir 3a through the spool 6, the ring 3 and the stopper 7 are drawn into the fixed mold 1 to move the movable resin as shown in FIG. The mold 2 is moved toward the fixed mold 1 to bring them into contact with each other, and the mold is clamped at a predetermined pressure. As a result, the molten resin filled in the resin reservoir 3a is spread over the entire cavity C to perform molding.

In Japanese Utility Model Application Laid-Open No. 63-192015, a filling piston communicating with the plasticizing means is separately provided in a fixed mold, and after the two molds are clamped, the filling piston is supplied from the plasticizing means. A molding apparatus has been proposed in which the molten resin to be supplied is once fed into the filling piston, and then the molten resin is filled into the cavity by the filling piston.

[0006]

The former molding apparatus has the following problems.
That is, in the initial stage of molding in which the molten resin is spread over the entire cavity C, there is a large gap between the two dies 1 and 2, and the resin being spread into the cavity C is brought into contact with the outside air. Not only does the property of the resin change, but the change is not constant, so that the molding conditions become unstable. As a result, the quality of the obtained molded product becomes unstable.

In the former molding apparatus, it is ideal that the molten resin reaches the end of the cavity C immediately before the butting surfaces of the two dies 1 and 2 come into contact with each other. Since the molten resin to be filled is usually slightly larger than the minimum volume of the cavity C in order to mold the resin into the shape described in the above, or to prevent the occurrence of sink marks or the like, both molds are used. Before the gap between the molds 1 and 2 reaches the set value, the molten resin reaches the end of the cavity C and the molten resin seeps out between the butted surfaces of the two dies 1 and 2, causing burrs. It is easy to be.

Further, in the former molding apparatus, a pressurizing means separate from the mold clamping means is required for the operation of filling the cavity C with the molten resin and for maintaining the pressure, so that the configuration tends to be complicated.

On the other hand, in the latter molding apparatus, the two molds are abutted to each other and the molten resin is filled in a state in which a closed cavity having a fixed volume is formed. Can be expected. However, this molding apparatus also requires a filling piston that is operated separately from the mold clamping means for filling and holding pressure in the cavity, and the installation position of the filling piston is inside the fixed mold. Due to the limitation, there remains a problem that the structure tends to be complicated.

Further, in any of the molding apparatuses, the step of filling the resin reservoir (filling piston) with the molten resin needs to be provided independently of the other steps, so that the molding cycle becomes longer. is there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is directed to a molding apparatus having a resin reservoir.
A homogeneous molded product can be obtained without obstructing the flow of resin during molding, and the filling of the molten resin into the cavity and the holding pressure after completion of filling are also used as mold clamping means, making the configuration complicated. It is a first object to provide a molding apparatus in which the occurrence is suppressed. A second object of the present invention is to prevent the molding cycle from being lengthened by performing the filling operation of the molten resin into the resin reservoir overlapping with other steps.

[0012]

According to a first aspect of the present invention, there is provided a molding apparatus comprising: a pair of molds forming a cavity; and a mold clamping force of the molds. A fixed plate to be supported, a movable plate that is provided so as to be relatively movable with respect to the fixed plate, and to which one of the molds is attached;
An intermediate plate disposed between the movable platen and the fixed platen, the other die being attached thereto, and an intermediate plate provided movably relative to the movable platen and the fixed platen; Between the and the fixed board, while the molten resin filled in the cavity is stored, by the relative movement of the intermediate board and the fixed board, there is provided an auxiliary cylinder that sends the molten resin to the cavity, An intermediate board movement control means for controlling the relative movement between the intermediate board and the fixed board is provided.

According to a second aspect of the present invention, in the first aspect, the auxiliary cylinder is provided with a backflow preventing means for preventing a flow of the molten resin in a direction opposite to a filling direction of the auxiliary cylinder. It is characterized by.

Further, the molding apparatus according to claim 1, wherein the intermediate plate movement control means, characterized in that it is a hydraulic cylinder disposed between the fixed plate and the intermediate plate.

[0015]

[0016]

According to the molding apparatus of the first aspect of the present invention,
When the mold clamping is completed, the intermediate plate is controlled by the intermediate plate movement control means so as to be kept at a predetermined distance from the fixed plate, and the molten resin is filled into the cavity through the auxiliary cylinder to perform filling. When the filling is completed, by the operation of the intermediate plate movement control means, the two dies are moved toward the fixed platen together with the movable platen and the intermediate plate by the clamping force in a state where the molds are clamped. As a result, the auxiliary cylinder is operated, and the molten resin stored in the auxiliary cylinder is compressed, thereby maintaining the pressure.

In the mold opening step after the completion of the pressure holding, an external force acts on the movable platen in the mold opening direction. After moving in the opening direction, the movement of the intermediate plate is restricted, and the mold is opened with the movement of the movable plate. By controlling the movement of the intermediate plate by such an intermediate plate movement control means, the auxiliary cylinder is operated in a direction of increasing its internal volume, whereby the auxiliary cylinder is filled with the molten resin.

As described above, the feeding of resin into the cavity from the auxiliary cylinder constituting the resin reservoir and the holding pressure are performed by the mold clamping operation of the mold. The supply of the molten resin to the auxiliary cylinder is performed in parallel with the mold opening step.

Further, according to the molding apparatus of the second aspect of the present invention, when the auxiliary cylinder is operated in a direction to reduce its volume by the mold clamping force at the time of holding the pressure,
The backflow preventing means prevents the backflow of the molten resin from the auxiliary cylinder, thereby increasing the internal pressure of the auxiliary cylinder, thereby maintaining the pressure. Therefore, the auxiliary cylinder and the plasticizing means can be separated during the pressure-holding step, and the plasticization and metering of the resin for molding in the next cycle are performed in parallel during the pressure-holding step.

According to the molding apparatus of the first aspect of the present invention, since the intermediate plate movement control means is constituted by the fluid pressure cylinder, the hydraulic oil supplied to the fluid pressure cylinder can be controlled. The relative position control between the intermediate plate and the fixed plate is finely controlled. As a result, the start position of the mold clamping position and the like are controlled with high accuracy, and the operation amount of the auxiliary cylinder during the pressure holding is controlled. Is controlled with high precision, and the holding pressure is controlled with high precision.

[0021]

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. In FIG. 3, reference numeral 10 indicates a molding apparatus according to the present embodiment, and an injection molding machine is illustrated in the present embodiment. The molding apparatus 10 includes a pair of dies 11 and 12 that form a cavity, and a pair of these dies 11 and 12.
12, a fixed platen 13 for supporting the mold clamping force,
3, a movable plate 14 to which one mold 11 is attached, and a movable plate 14 disposed between the movable plate 14 and the fixed plate 13 to which the other mold 12 is attached. A movable plate 14 and an intermediate plate 15 movably provided with respect to the fixed platen 13, wherein the molten resin filled in the cavity is stored between the intermediate plate 15 and the fixed platen 13. At the same time, a schematic configuration is provided in which an auxiliary cylinder 16 is provided for filling the cavity with the molten resin by the relative movement of the intermediate plate 15 and the fixed plate 13 in the approaching direction.

Next, the details will be described. The mold 11 is located at a position facing the movable plate 14.
A mold clamping cylinder 17 for opening and closing the mold 12 is fixed via a mold clamping cylinder fixing plate 18;
A clamping piston 19 of the clamping cylinder 17 is integrally connected to the movable platen 14.

A guide pin 20 which penetrates the one mold 11 and protrudes toward the other mold 12 is fixed to the movable platen 14 and is exposed to the cavity. A mold internal pressure detecting rod 21 for transmitting the internal pressure, and a mold internal pressure sensor 22 which is connected to one end of the mold internal pressure detecting rod 21 and detects the internal pressure transmitted by the mold internal pressure detecting rod 21. Have been. Further, the one mold 11 is provided with the other mold 1.
2, a PL surface for detecting whether or not the butted surface (that is, a parting line surface, hereinafter abbreviated as a PL surface) is brought into contact, that is, whether or not the mold clamping is completed. A sensor 23 is provided.

A guide bush 24 for positioning the two dies 11 and 12 is attached to the other die 12 by fitting a guide pin 20 attached to the one die 11. A stopper 25 having one end fixed to the fixed platen 13 is slidably provided. And this stopper 25
When the intermediate board 15 is engaged with the intermediate board 15 in a state where the intermediate board 15 is separated from the fixed board 13 by a predetermined distance, the maximum separation amount between the two is regulated.

The auxiliary cylinder 16 is provided with the intermediate plate 1.
5 and a pressure holding piston 16b slidably fitted to the cylinder body 16a and fixed to the fixed platen 13. The pressure holding piston 16b A spool 16c for guiding the molten resin supplied from the plasticizing means 26 described later into the auxiliary cylinder 16 is formed inside. Here, a resin reservoir in which the molten resin is stored is formed by the cylinder body 16a and the tip end surface of the pressure-holding piston 16b.

In the present embodiment, a backflow preventing means for preventing the molten resin in the auxiliary cylinder 16 from flowing back to the plasticizing means 26 is provided at the tip of the pressure-holding piston 16b of the auxiliary cylinder 16. A check valve 27 is provided. As shown in FIGS. 4 and 5, the check valve 27 is a valve seat 27a having a spherical inner surface formed at the distal end of the spool 16c of the holding piston 16b.
And a spherical valve element 27b provided so as to be able to contact and separate from the valve seat 27a, and is integrally attached to the tip of the pressure-holding piston 16b to prevent the valve element 27b from coming off from the pressure-holding piston 16b. And a stopper 27c. In the state where the stopper 27c is engaged with the valve body 27b,
The inside of the cylinder body 16a and the spool 16c
And a communication passage 28 is formed to communicate with.

The plasticizing means 26 penetrates through the fixed platen 13 and is brought into contact with the base end of the pressure-holding piston 16b. The heating cylinder 29 having a nozzle to be brought into contact with the pressure-holding piston 16b. And a screw 30 slidably and rotatably mounted in the heating cylinder 29 so as to be slidable and rotatable in its length direction, and connected to the outer wall of the heating cylinder 29 to supply the raw material into the heating cylinder 29. Hopper 31 and heating cylinder 2
9, an injection cylinder 32 provided integrally with the rear end portion to move the screw 30;
A hydraulic motor 33 for rotating the
And a screw position sensor 34 for detecting the position of zero.

In this embodiment, the intermediate board 1
A positioning cylinder 35 is provided between the fixed plate 13 and the fixed plate 13 as intermediate plate movement control means for restraining relative movement between the intermediate plate 15 and the fixed plate 13 when the two dies 11 and 12 are clamped. ing. This positioning cylinder 35
The cylinder body 35a is fixed to the intermediate plate 15, and the tip of the piston 35b is fixed to the fixed plate 13.

Further, the intermediate plate 15 detects the position of the intermediate plate 15 with respect to the fixed plate 13 to detect the position of the pressure-holding piston 16b of the auxiliary cylinder 16 with respect to the cylinder body 16a. A detection sensor 36 is attached.

On the other hand, the mold clamping cylinder 17, the injection cylinder 32, and the positioning cylinder 35 include:
The solenoid valves 37, 38, and 39 are connected to each other, and a hydraulic pump 40 that generates hydraulic oil is connected to each of the solenoid valves 37, 38, and 39, and these solenoid valves 37, 38, and 39 are connected. Each cylinder 17
The operation of each of the cylinders 17, 32, and 35 is controlled by controlling the mode of supply of the hydraulic oil to the cylinders 32, 35.

The cylinders 17, 32, 35
Of the hydraulic oil supplied to the mold clamping cylinder 17, the hydraulic oil pressure in the mold clamping direction for the injection cylinder 32, the hydraulic oil pressure in the injection direction for the injection cylinder 32, and the intermediate oil pressure for the positioning cylinder 35. The hydraulic oil pressure in the direction in which the board 15 is separated from the fixed board 13 is determined by pressure sensors 41, 42, and 43.
Is to be detected.

Further, the solenoid valves 37, 38, and 39 are provided with pressure adjusting valves 44, 45, and 46 for adjusting the pressure of hydraulic oil supplied to devices controlled by the respective solenoid valves. A heating means such as a resistance heating element is provided on the cylinder body 16a and the pressure-holding piston 16b of the auxiliary cylinder 16 so as to keep the resin filled therein in a molten state. A heat insulating material is interposed between the cylinder body 16a, the intermediate plate 15, and the other mold 12, and the cylinder body 16a
The heat of a is prevented from being dissipated through the intermediate plate 15 and the other mold 12.

Reference numeral 47 in FIG. 3 denotes a control device for controlling the operation of the molding apparatus 10 of this embodiment.

Next, the operation of the embodiment constructed as described above will be described with reference to the control procedure performed by the control device 47 shown in the control flow charts of FIGS. 6 to 8 and the operation explanatory diagrams shown in FIGS. 9 and 10. It is explained based on. First, FIG.
In the mold opening state as shown in FIG. 5, the intermediate plate 15 is locked in a predetermined position by being pressed by the positioning cylinder 35 in a direction away from the fixed plate 13 and engaged with the stopper 25. . Further, as described later, in the plasticizing means 26, the screw 30 is located at the retracted position, and the melting of the resin for filling and the measurement thereof are completed. Further, in the auxiliary cylinder 16 which is continuous with the plasticizing means 26,
As described above, since the intermediate plate 15 and the fixed platen 13 are held at the maximum separation distance, they are held at the position where the maximum volume is obtained, and the inside thereof is
And a state where the continuous molten resin is filled.

When the molding operation is started from such a mold opening state (step S1), the position of the pressure holding piston 16b is detected (step S2). The position of the pressure-holding piston 16b is detected by an output signal from a pressure-holding piston position detection sensor 36 provided on the intermediate board 15.

When the position of the pressure holding piston 16b is detected as described above, the pressure holding piston 1
It is determined whether or not the pressure-holding piston 16b is at a predetermined position (Step S3. If it is determined that the pressure-holding piston 16b is not at the predetermined position, the process returns to Step S2, and the pressure-holding piston 16b is moved to a predetermined position. This process is repeated until the position of the pressure-retaining piston 16b is adjusted, for example, by adjusting the relative position between the intermediate plate 15 and the fixed plate 13 by the positioning cylinder 35. After the adjustment, the positioning cylinder 35 is locked, whereby the movement of the intermediate plate 15 is restricted, and the pressure-holding piston 16b is held at a predetermined position.

On the other hand, the holding pressure piston 1
When 6b is positioned at the predetermined position, the mold clamping cylinder 17 is driven to start the mold clamping process (step S).
4) The movable platen 14 is moved toward the intermediate plate 15, and the two molds 11 and 12 are brought into contact with each other to complete the mold clamping. The mold clamping pressure during such mold clamping is supported by the positioning cylinder 35.
Here, when the mold clamping process is started, detection of the PL surface is performed (step S5). This is set to a standby state for the control device 47 to receive a detection signal from the PL surface sensor 23. Is Rukoto. Then, the completion of the mold clamping described above is determined by the presence or absence of a detection signal from the PL surface sensor 23 (step S6), and when this detection signal is present, it is determined that mold clamping has been completed. In addition, the P
When it is determined that there is no detection signal from the L surface sensor 23, it is determined that the mold clamping has not been completed, and the process returns to step S5. Therefore, the next process is not performed until the mold clamping is completed.

FIG. 9 shows the state of each member at the time of completion of the mold clamping. In this mold clamping completed state, the positioning cylinder 35 is locked, but since the mold clamping force applied from the mold clamping cylinder 17 is large, the positioning cylinder 35 is slightly retracted in the contraction direction until it is balanced with this mold clamping force. It is moved to.

When the mold clamping is completed as described above, the injection process is started (step S7), and at the same time, the position detection of the screw 30 is started based on the detection signal from the screw position sensor 34 (step S8).

Then, during the injection process, it is determined whether or not the position of the screw 30, which continuously changes, reaches a predetermined position (step S9). When the screw 30 reaches the predetermined position, the injection process is completed. When it is determined that the screw 30 has been moved, the movement of the screw 30 is stopped, and in this embodiment, the process proceeds to a pressure holding step (step S10) and a measuring step (step S15) performed in parallel with the pressure holding step. If the screw 30 has not reached the predetermined position, it is determined that the injection process has not been completed, and the process returns to step S8. Therefore, the process shifts to the subsequent processes on condition that the completion of the injection process based on the position detection signal of the screw 30 is confirmed.

In this injection step, the molten resin injected from the tip of the heating cylinder 29 by the screw 30 flows into the auxiliary cylinder 16 while pushing and opening the check valve 27 at the tip of the pressure-holding piston 16b. Along with the molten resin stored in the auxiliary cylinder 16,
The cavity is filled.

Next, the above-mentioned pressure holding step will be described. When this pressure-holding step is performed, pressure control is performed on the positioning cylinder 35, and as shown in FIG. 10, the movable platen 14 and the intermediate plate 15 push the two dies 11 and 12 at a predetermined pressure. It is moved by a predetermined amount toward the fixed platen 13 while maintaining the mold-clamped state. As a result, the pressure-holding piston 16b is pushed into the cylinder body 16a, but the resin in the auxiliary cylinder 16 is released from the check valve 2
7 prevents the backflow to the plasticizing means 26 side, and as a result, the resin pressure in the auxiliary cylinder 16 is increased, and the pressure in the resin in the cavity is maintained.

In such a pressure-holding step, the position of the pressure-holding piston 16b is detected based on a detection signal from the pressure-holding piston position detecting sensor 36 (step S11), and the position of the pressure-holding piston 16b is detected. It is determined whether the position has reached a predetermined position (step S1).
2), the process proceeds to the next step S13 on condition that the pressure holding piston 16b has reached a predetermined position. If the pressure-holding piston 16b has not reached the predetermined position, the processing after step S11 is repeated. The determination in step S12 is a process for setting the pressure at the time of holding pressure to a predetermined pressure, and the pressure in the auxiliary cylinder 16 is determined by the position of the holding pressure piston 16b. The position of the pressure-holding piston 16b is set in advance, and the pressure-holding piston 1 is located at the predetermined position.
The predetermined pressure is obtained by positioning 6b.

As described above, when the pressure-holding piston 16b reaches the predetermined position, it is determined whether or not a predetermined time has elapsed after the arrival (step S13). In step S14, a cooling step is performed, and after processing such as opening the mold and releasing the molded product is performed, the process proceeds to the next cycle.

Next, a measuring step performed in parallel with the above-mentioned pressure holding step will be described with reference to FIG. The reason why the measuring step is performed in parallel with the pressure holding step is that the auxiliary cylinder 16 and the plasticizing means 26 are separated from each other by the action of the check valve 27 during the pressure holding. It is due to. When this measuring step is started, the screw 30 is driven to rotate by the hydraulic motor 33, so that the raw material supplied from the hopper 31 is sent to the front of the screw 30 while being plasticized. Then, the screw 30 is retracted with the increase in the pressure of the molten resin in front due to the feeding of the plasticized resin to the front, and the position of the screw 30 is detected by the screw position sensor 34. (Step S16), it is determined whether the position of the screw 30 is a predetermined position (whether the screw 30 has been retracted to the predetermined position) (Step S17).

Here, since the retreat distance of the screw 30 corresponds to the amount of resin sent out in front thereof,
When the screw 30 is retracted to a predetermined position, a predetermined amount of molten resin is fed in front of the screw 30,
It is considered that a predetermined amount of the molten resin has been measured. Therefore, when it is determined in step S17 that the screw 30 has reached the predetermined position, it is determined that the weighing has been completed, and the process proceeds to the next cycle.

As described above, the molding apparatus 10 of the present embodiment is a molding apparatus having a resin reservoir,
The resin is filled into the cavity with the block 12 closed, so that the filled resin does not come into contact with the outside air. As a result, the resin is prevented from being deteriorated, and the molded product is uniform and has high dimensional accuracy. Is obtained.

Further, since the mold clamping operation and the pressure holding operation are performed by the mold opening / closing operation by the mold clamping force, it is not necessary to separately provide a pressurizing device for the pressure holding, and the structure is simplified. Is achieved. The filling operation of the resin into the auxiliary cylinder 16 as a resin reservoir is performed by a positioning cylinder 35 provided separately, and the positioning cylinder 35 is provided with a resin supply path to the auxiliary cylinder 16. Since it can be installed regardless of the above, the degree of freedom of its configuration and design can be increased.

Further, in this embodiment, since the resin is filled into the auxiliary cylinder 16 at the same time when the mold is opened, it is not necessary to separately provide a step of filling the resin into the auxiliary cylinder 16. Therefore, the lengthening of the molding cycle is suppressed as compared with the related art.

In the present embodiment, on the other hand, the check valve 27 is provided at the tip of the pressure-holding piston 16b of the auxiliary cylinder 16, so that the function of the pressure-holding is achieved by the auxiliary cylinder 1.
6, whereby the auxiliary cylinder 16 and the plasticizing means 26 are separated from each other at the time of pressure-holding, so that the plasticizing means 26 can be operated at the time of pressure-holding. The operation of measuring the molten resin is performed in parallel. Therefore, the pressure-holding step and the measuring step are overlapped, and the molding cycle can be shortened from this point as well.

In the above-described first embodiment, an example is shown in which the resin is filled into the cavity only by advancing the screw 30 of the plasticizing means 26. Instead, the auxiliary cylinder 16 is used. The filling operation can be performed together. That is, by continuously or simultaneously performing the filling operation using the screw 30 and the auxiliary cylinder 16, the filling amount can be largely changed. Thus, for example, when a change in the mold requires an increase in the amount of the filled resin, a change in the program in the control system (for example, a change in the pressure-holding start position) can provide an immediate and simple response. It becomes possible.

Next, a second embodiment of the present invention will be described with reference to FIGS. This embodiment is almost the same as the first embodiment except that the cylinder main body 50a of the positioning cylinder 50 constituting the intermediate plate movement control means is attached with the plasticizing means 26 of the fixed platen 13. And the injection cylinder 32 is omitted, and the plasticizing means 26
Is limited to the rotation operation for plasticizing the resin. Accordingly, the solenoid valve 39 for controlling the supply of the working oil supplied to the injection cylinder 32 is also omitted. And FIG.
In the hydraulic circuit shown in FIG. 1, an electromagnetic valve 51 for controlling the supply of hydraulic oil supplied to the hydraulic motor 33 for rotating the screw 30 is newly shown for convenience of explanation.

Next, the operation of the embodiment having the above-described structure will be described. First, immediately before the start of molding, as shown in FIG. 11, the intermediate plate 15 is held at a predetermined position with respect to the fixed plate 13 by the positioning cylinder 50, and the movable plate 14 is held at the mold open position by the mold clamping cylinder 17. ing. Further, the raw material supplied from the hopper 31 is plasticized by the plasticizing means 26, and the molten resin is filled in the auxiliary cylinder 16 having the maximum volume.

When the molding operation is started, first,
The movable platen 14 is moved toward the stopped intermediate plate 15 by the mold clamping cylinder 17, and the two molds 11.
The mold clamping is performed by bringing the 12 into contact (see FIG. 12). At this time, the mold clamping force is
5 is supported by a positioning cylinder 50 holding the stationary state.

By controlling the pressure of the positioning cylinder 50, the movable platen 14 and the intermediate plate 15 are connected to both the molds 11 and 1, as shown in FIG.
2 is moved to the fixed platen 13 side by a predetermined amount while holding the mold in a clamped state. When the intermediate plate 15 and the fixed platen 13 approach each other, the auxiliary cylinder 16 is operated in a direction to reduce the volume, whereby the molten resin filled therein is filled into the cavity, and The filling amount is determined by the moving amount of the intermediate board 15.

When the filling step is completed, the movable platen 14 and the intermediate platen 15 are further moved toward the fixed platen 14 by a predetermined amount. Is performed.

Further, when the above-mentioned holding pressure is completed, the movable plate 14 and the intermediate plate 15 are integrally separated from the fixed plate 14 by controlling the hydraulic oil supplied to the mold clamping cylinder 17 and the positioning cylinder 50. (Ie, mold opening is started). In the process of this movement, when the intermediate plate 15 is separated from the fixed plate 14 by a predetermined distance, the intermediate plate 15 is stopped as shown in FIG.

Then, in synchronization with the opening operation, the auxiliary cylinder 16 is operated in a direction to increase its internal volume, and the plasticizing means 26 is operated to plasticize the raw material by the screw 30. The plasticization is started, and the plasticized molten resin is sent out from the tip of the heating cylinder 29, and the molten resin is sent into the auxiliary cylinder 16. The feeding of the molten resin to the auxiliary cylinder 16 is completed when the operation of the plasticizing means 26 is stopped together with the stop of the intermediate plate 15, whereby the required amount of the molten resin is measured in the next molding cycle. Is completed.

On the other hand, even after the above-mentioned intermediate plate 15 is stopped, the movable plate 14 is continuously moved in the mold opening direction by the mold clamping cylinder 17, and as shown in FIG. By stopping at a position separated by a predetermined distance, the mold opening is completed. Thereafter, after the molded product is released, the molding cycle described above is repeated.

As described above, this embodiment is also a molding apparatus having a resin reservoir. However, since the cavity is filled with the resin while the dies 11 and 12 are closed, the resin is filled. As a result, the resin does not come into contact with the outside air, and as a result, the resin is prevented from being deteriorated, and a molded product having uniformity and high dimensional accuracy can be obtained.

Further, since the mold clamping operation and the pressure holding operation are performed by the mold opening / closing operation by the mold clamping force, it is not necessary to separately provide a pressurizing device for holding the pressure. Since the plasticizing means 26 is concentrated only on the plasticizing function of the raw material, a device for moving the screw 30 in the longitudinal direction (for example, the injection cylinder 32 in the first embodiment) is omitted, and as a result, The structure is further simplified.

The positioning cylinder 50 for filling the resin into the auxiliary cylinder 16 as a resin reservoir can be installed irrespective of the supply path of the resin to the auxiliary cylinder 16. And the degree of freedom of design is increased.

Further, in this embodiment, when the mold is opened, the filling of the resin into the auxiliary cylinder 16, that is, the measurement is performed in parallel, so that the mold opening and the measurement are performed in an overlapped manner. Is achieved.

Next, a third embodiment of the present invention will be described with reference to FIG.
6 will be described. In the present embodiment, the mold clamping mechanism 60 (60a
60b) are provided in parallel, and a single plasticizing means 61 is connected to these mold clamping mechanisms 60a and 60b.

In the illustrated example, while one mold clamping mechanism 60a is performing a cooling operation, another operation such as mold opening, measuring, and releasing is performed in the other mold clamping mechanism 60b. ing. Therefore, by performing these operations alternately in the two mold clamping mechanisms 60a and 60b, the stopping time of the plasticizing means 61 is reduced, and the molding efficiency is increased.

In particular, when molding thick products,
Since the cooling time tends to be long, the effect of improving the molding efficiency by adopting the configuration of this embodiment becomes remarkable.

It should be noted that the various shapes, dimensions, and the like of the constituent members shown in each of the above embodiments are merely examples, and can be variously changed based on design requirements and the like.

For example, in each of the above-described embodiments, the example in which the check valve 27 is provided at the tip of the pressure holding piston 16b has been described, but this may be omitted. In this case, the backflow of the molten resin at the time of holding pressure is performed by the plasticizing means 26.
It is necessary to carry out with the screw 30.

In each of the embodiments, the hydraulic cylinder is exemplified as the intermediate plate movement control means. Instead, as shown in FIG. It is also possible to adopt a configuration in which a resilient member 70 (for example, a coil spring or the like) that repels in a direction away from the main body is interposed. With such a configuration,
A hydraulic circuit for operating the intermediate plate moving means and a control system associated therewith can be omitted, and the configuration can be further simplified.

[0071]

As described above, according to the first aspect of the present invention,
Is a pair of dies that form a cavity, a fixed plate that supports the clamping force of these dies, and are provided movably relative to the fixed plate, and one of the dies is mounted. Movable plate, and an intermediate plate provided between the movable plate and the fixed plate, the other die is attached, and the movable plate is provided so as to be relatively movable with respect to the movable plate and the fixed plate. An auxiliary cylinder for feeding the molten resin into the cavity by the relative movement between the intermediate plate and the fixed plate while the molten resin filled in the cavity is stored between the intermediate plate and the fixed plate. Is provided, and intermediate board movement control means for controlling the relative movement between the intermediate board and the fixed board is provided. The following excellent effects are obtained.

In spite of having the resin reservoir, the cavity can be filled with the resin while the mold is closed, and the resin filled in the mold is prevented from contacting the outside air. As a result, a change in the temperature of the resin can be kept to a minimum, and a molded product with uniform and high dimensional accuracy can be obtained.

Further, by the mold opening / closing operation by the mold clamping force, not only the mold clamping operation of the mold but also the pressure holding operation can be performed, so that it is not necessary to separately provide a pressurizing device for the pressure holding. Thus, the configuration can be simplified.
Since the filling operation of the resin into the auxiliary cylinder as the resin reservoir can be performed by controlling the position of the intermediate plate by the intermediate plate position control means, the installation position can be set regardless of the filling path. As a result, the degree of freedom in the configuration and design of the device can be increased.

Further, at the time of opening the mold, the filling or the metering of the resin into the auxiliary cylinder, which is a resin reservoir, can be performed in parallel, whereby the lengthening of the molding cycle can be suppressed.

In the molding apparatus according to a second aspect of the present invention, the auxiliary cylinder according to the first aspect is provided with a backflow preventing means for preventing a flow of the molten resin in a direction opposite to the filling direction. It has the following excellent effects.

At the time of holding the pressure, the check valve provided in the auxiliary cylinder can prevent the backflow of the molten resin, so that the function of holding the pressure can be given to the auxiliary cylinder. Thereby, at the time of pressure holding, the auxiliary cylinder and the plasticizing means for feeding the molten resin to the auxiliary cylinder are separated, and the plasticizing means can be operated independently. Thus, in the case where the plasticizing means for supplying the molten resin to the auxiliary cylinder measures the molten resin, the operation of measuring the molten resin necessary for the next cycle is performed in parallel during the pressure holding. Therefore, the pressure-holding step and the measuring step are overlapped, and the molding cycle can be shortened.

Further, in the molding apparatus according to the first aspect of the present invention , the intermediate plate movement control means is a fluid pressure cylinder disposed between the fixed plate and the intermediate plate. It has the following excellent effects.

Since the control of the operation amount of the fluid pressure cylinder is performed with high precision, the position control of the intermediate plate can be performed with high precision, whereby the mold clamping position control, the pressure holding control, or the metering control can be performed. And other controls can be reliably performed.

[0079]

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a conventional molding apparatus having a resin reservoir, showing a state in which a mold is being clamped.

FIG. 2 is a longitudinal sectional view showing an example of a conventional molding apparatus having a resin reservoir, showing a mold-clamped state.

FIG. 3 shows a first embodiment of the present invention and is a schematic view of an entire apparatus.

FIG. 4 is an enlarged vertical sectional view showing a first embodiment of the present invention and showing a check valve attached to an auxiliary cylinder.

FIG. 5 is an enlarged longitudinal sectional view showing a first embodiment of the present invention and showing a check valve attached to an auxiliary cylinder.

FIG. 6 is a flowchart illustrating a part of control of a molding operation according to the first embodiment of the present invention.

FIG. 7 is a flow chart showing a first embodiment of the present invention and showing a part of control of a molding operation.

FIG. 8 is a flowchart showing a first embodiment of the present invention and showing a part of control of a molding operation.

FIG. 9 is an operation explanatory view in the first embodiment of the present invention, and is a longitudinal sectional view showing a time point when mold clamping is completed.

FIG. 10 is an operation explanatory view of the first embodiment of the present invention.
It is a longitudinal cross-sectional view which shows the time of filling of resin into a cavity and completion of pressure holding.

FIG. 11 shows a second embodiment of the present invention, and is a schematic view of an entire apparatus.

FIG. 12 is an operation explanatory view in a second embodiment of the present invention;
It is a longitudinal cross-sectional view which shows the time point of completion of mold clamping.

FIG. 13 is an operation explanatory view in a second embodiment of the present invention,
It is a longitudinal cross-sectional view which shows the time of filling of resin into a cavity and completion of pressure holding.

FIG. 14 is an operation explanatory view in a second embodiment of the present invention;
It is a longitudinal cross-sectional view which shows the time of completion of measurement in the middle of mold opening.

FIG. 15 is an operation explanatory view in a second embodiment of the present invention;
It is a longitudinal cross-sectional view which shows the time of a mold opening completion.

FIG. 16 shows a third embodiment of the present invention, and is a longitudinal sectional view of a mechanism section.

FIG. 17 is a longitudinal sectional view of a mechanism section showing a modification of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Molding apparatus 11 Die 12 Die 13 Fixed board 14 Movable board 15 Intermediate board 16 Auxiliary cylinder 17 Mold clamping cylinder 26 Plasticization means 27 Check valve (Backflow prevention means) 29 Heating cylinder 30 Screw 32 Injection cylinder 35 Positioning cylinder ( Intermediate disk position control means) 50 Positioning cylinder (Intermediate disk position control means)

Claims (2)

(57) [Claims] 1. A pair of molds forming a cavity, a fixed platen for supporting a mold clamping force of these molds, and provided so as to be relatively movable with respect to the fixed platen, and one of the molds is attached. A movable plate, disposed between the movable plate and the fixed plate, and the other mold is attached,
An intermediate plate provided so as to be relatively movable with respect to the movable plate and the fixed plate, and between the intermediate plate and the fixed plate, molten resin to be filled in the cavity is stored, and An auxiliary cylinder for feeding the molten resin into the cavity is provided by relative movement of the board and the fixed board in the approaching direction, and between the intermediate board and the fixed board, an intermediate board movement for controlling the relative movement between the two. A molding apparatus provided with control means , wherein the intermediate board movement control means is provided between the fixed board and the intermediate board.
A molding apparatus, characterized in that the molding apparatus is a fluid pressure cylinder disposed in the apparatus. 2. The molding apparatus according to claim 2, wherein the auxiliary cylinder is provided with a backflow preventing means for preventing a flow of the molten resin in a direction opposite to a filling direction of the auxiliary cylinder.