JPH05138683A - Rotary injection molding machine - Google Patents

Abstract

PURPOSE:To provide a molding machine which can prevent a mold being not user for molding from rotating uselessly when a mold 4 is exchanged and by which improvement of productivity can be attempted and which is especially fittable to the production for multi-kinds and small amt. CONSTITUTION:A seating face 54 set by a guide pin 51, a clamp 52 and a stopper 53 is formed on an intermittently rotating rotary table 22 by the same distance of 90 deg. in the circumferential direction. Molds M are removably positioned on each of these seating faces 54. A clamping-injection station S1 having a clamping apparatus 23 and an injection apparatus 1, a cooling station S2 holding and cooling the mold, a mold-opening station S3 opening the mold and taking an injection-molded item out and a mold-exchanging station S4 equipped with a mold-exchanging apparatus are successively positioned in this order at corresponding positions to the position of each mold M along the rotating direction of the rotary table 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary injection molding machine in which a plurality of molds are arranged on a rotary table and the molds are sequentially injection-molded as the rotary table rotates. It is a thing.

[0002]

2. Description of the Related Art As a rotary injection molding machine having such a structure, there is, for example, one described in Japanese Patent Laid-Open No. 165922/1990. This is to attach and detach a plurality of molds on a rotary table that rotates for indexing, and at the positions corresponding to each mold, mold clamping / injection station, mold exchange station, cooling station,
The mold opening station is sequentially provided in this order, and the purpose is to effectively utilize a narrow space to perform efficient injection molding work.

Further, in the injection molding machine having such a structure, a mold exchanging station is partially provided,
It is a device suitable for a production method that has a recent tendency to perform a high-mix low-volume production because die replacement work can be easily performed.

[0004]

However, in the rotary type injection molding machine having such a structure, the mold exchanging station for exchanging the mold as described above is arranged along the rotating direction of the rotary table. It is located next to the clamping / injection station. Therefore, when exchanging the mold,
The mold to be exchanged is once transferred to the mold clamping / injection station after the last molded product is taken out at the mold opening station, where the mold is not clamped and injected and the mold is empty. Then, it will be sent to the mold change station and carried out. That is, the mold to be replaced is not used for molding during the half-round rotation of the rotary table from the mold opening station to the mold replacement station (1/2 of one molding cycle).

On the other hand, the mold carried into the rotary table for molding a new lot is mounted on the empty rotary table at the mold exchange station,
It is sent to the mold clamping / injection station through the cooling, station, and mold opening station, where the mold clamping and resin injection are performed for the first time for molding. That is, this exchanged mold is not used for molding during the rotation of the rotary table from the mold replacement station to the mold clamping / injection station for 3/4 revolution (3/4 of one molding cycle). ..

Therefore, in the rotary type injection molding machine having the above-mentioned structure, when exchanging the mold, an empty mold is placed on the rotary table for a total of one rotation of the rotary table or more and the circuit is rotated. Therefore, it is inevitable that a production cycle will be lost and the production efficiency will be reduced by this amount. This tendency becomes particularly noticeable in the case of the above-mentioned high-mix low-volume production in which the die replacement frequency is high.

[0007]

The present invention has been made to solve the above problems, and four molds can be attached to and removed from a rotary table that rotates intermittently at equal intervals in the circumferential direction. Place the mold clamping / injection station having the mold clamping device and the injection device at the position corresponding to the position of each mold when the intermittent rotation is stopped, along with the rotation direction of the rotary table, and the mold. It is characterized in that a cooling station for holding and cooling, a mold opening station for opening a mold to take out an injection-molded product, and a mold exchanging station equipped with an exchanging device for exchanging the mold are sequentially arranged. It is a thing.

[0008]

[Operation] In the rotary type injection molding machine having such a structure, the die exchange station is connected to the die opening station and the die clamping station.
Since it is located between the injection stations, when replacing a mold that has been molded for a given lot, this replacement mold will be used immediately after the injection molded product is taken out at the mold opening station. It is sent to the exchange station and taken out from the rotary table. On the other hand, in order to mold a new lot, the mold loaded and replaced on the rotary table at the mold exchange station is immediately clamped at the mold clamping / injection station immediately after the mold exchange station and the resin is clamped. Is injected and used for molding.

That is, according to the rotary type injection molding machine having the above-mentioned structure, when the mold is exchanged, the mold which is not used for the molding is not placed on the rotary table and is not transported. It is possible to prevent a cycle loss, and consequently improve the production efficiency.

In such a rotary type injection molding machine, in consideration of the time required to carry out and carry in the mold at the mold replacement station and the molding process time at the other stations, the mold replacement is performed by the mold replacement. It may be carried out in two steps of carrying in and carrying out. In this case, a portion where the mold does not exist is formed on the rotary table. However, even in such a case, in the above-mentioned injection molding machine, the portion which is not used for molding occurs on the rotary table only during one rotation, and in the conventional injection molding machine, the molding is performed for more than one rotation. While the mold that has not been supplied is transferred, the loss in the molding cycle can still be suppressed.

[0011]

1 to 4 show an embodiment of the present invention, in which an injection device 1, a molding device 2, and a mold exchanging device 3 are shown.
It is roughly composed of and. However, the mold exchanging device 3 is omitted in FIGS. 1 and 2. Injection device 1
Is a well-known one in which a resin raw material inserted in the heating cylinder 11 is injected from a nozzle 12 at the tip of the heating cylinder 11 by a screw or the like, and is installed on a base 13 to form the molding device 2
It is said that they can move forward and backward freely.

The molding apparatus 2 is a rotary table 22 which is horizontally supported by being inserted through a central shaft 21 which is erected on the floor surface G, and above the position where the rotary table 22 faces the injection apparatus 1. The mold clamping device 23 arranged is generally composed of a mold clamping device 23 and a mold opening device 24 arranged on the opposite side of the center shaft 21. Then, of the board surface on the rotary table 22, a portion located immediately below the mold clamping device 23, that is, a portion facing the injection device 1 is defined as a mold clamping / injection station S1, and hereinafter, the rotary table 22 rotates. A cooling station S2, a mold opening station S3, and a mold changing station S4 are sequentially arranged in this order at intervals of 90 degrees along the direction (counterclockwise direction in FIG. 1).

The rotary table 22 includes the central shaft 2
1 is externally fitted via a bearing or the like, and the lower surface thereof is supported by contacting with a roller on a support column 25 which is erected on the floor surface G around the central axis 21, and is supported by the central axis 21. It is possible to rotate in the horizontal plane around the center. On the lower surface of the rotary table 22, there is provided a movable disk 26 that rotates coaxially and integrally with the rotary table 22 and has a gear formed on the outer periphery thereof. A drive device 28 having a drive gear 27 that meshes with is disposed. A control device (not shown) having an indexing mechanism for indexing the rotational position of the rotary table 22 by a proximity switch or the like is connected to the drive device 28, and the drive device is moved by receiving a signal from the control device. By stopping, the rotary table 22 is intermittently rotated and rotated by 90 °, and is positioned and stopped at a predetermined rotation position.

The mold clamping device 23 provided in the mold clamping / injection station S1 has two support shafts 31, 31 arranged together with the central shaft 21 so as to form a substantially equilateral triangle in plan view. A press device 33 is attached to the center of a substrate 32 provided so as to bridge 21 and the support shafts 31, 31. This press device 33 is a well-known device that raises and lowers a ram 34 by hydraulic pressure,
A movable plate 35 is attached to the lower end of the ram 34 so as to face the rotary table 22, and the ram 34 is lowered to narrow the mold M between the movable plate 35 and the rotary table 22. The central axis 21
Also, the dies M are clamped by using the columns 31, 31 as tie bars.

Further, in the mold opening device 24 arranged in the mold opening station S3, a lifting hydraulic cylinder 43 is provided on a top plate 42 supported by four columns 41 ,. A supporting plate 44 is attached to the lower end of the supporting plate 44 so as to face the rotary table 22, and further a clamp 45 that clamps an upper mold of a mold M described later is mounted on the lower surface of the supporting plate 44. Here, reference numeral 46 is provided vertically on the upper surface of the support plate 44, and
Is a rod-shaped guide member that is inserted into the insertion hole of and guides the support plate 44. The mold opening device 24 includes a support plate 4
4. A fall prevention device for preventing a drop of the top plate 42 and the upper die by inserting a bar-shaped piece at the tip of an insertion hydraulic cylinder horizontally provided on the top plate 42 into a long hole of a bar-shaped member erected on the upper surface. 57 is attached.

Further, on the peripheral portion of the support plate 44, a coupler for connecting to a mold side coupler and for connecting a hydraulic drive system for operating a core built in the mold M and a core operation confirmation are provided. And electrical contacts are installed. Further, below the rotary table 22 in the mold opening station S3, an air pressure supply device for releasing the molded product from the opened mold M and a hydraulic ejector for taking out the molded product are arranged. There is. However, these couplers, electrical contacts, air pressure supply devices, and hydraulic ejectors are not shown.

On the other hand, in the rotary table 22, on the board surface, from the inside of the rotary table 6 toward the outer peripheral side in plan view, at the positions corresponding to the stations S1 to S4 when the intermittent rotation is stopped. The guide pins 51 ... Are arranged in two rows. Further, two pairs of clamps 52 are arranged so as to face each other along the row of the guide pins 51, and further, inside the extension lines of the two rows of the guide pins 51, the rotary is seen in a plan view. A pair of stoppers 53 ... Are projectingly provided on the inner side and the outer peripheral side of the table 22. A portion of the board surface on the rotary table 22 surrounded by the guide pins 51, the stoppers 53, and the clamps 52 serves as a seat surface 54 on which the mold is mounted and fixed.

Further, on the seat surface 54, a plurality of rollers are axially mounted in series on a die lifter which can be moved up and down by a hydraulic cylinder so as to be sandwiched between the two rows of the guide pins 51 ... In plan view. Lift rollers 55,5
5 are laid. These lift rollers 55, 55
Is set so that the roller slightly protrudes from the board surface of the rotary table 22 when the die lifter rises, and the roller sinks into the board surface when the die lifter descends. Here, the amount of protrusion of the stoppers 53, 53 provided on the outer peripheral side of the rotary table 22 is set to be lower than the amount of protrusion of the rollers when the die lifter is raised.

Reference numeral 56 in the drawing denotes an automatic coupler of a hydraulic drive system for operating the clamp 52 and the hydraulic cylinder of the lift roller 55.
The auto coupler 56 is provided with a plug 56A arranged on the peripheral edge of the rotary table 22 for each seat surface 54, and a column 57 standing on the outside of the rotary table 22 near the mold exchanging station S4. Table 22
The plug 56 is attached so that it can move back and forth toward the side.
And a socket 56B that can be fitted in A. Reference numeral 58 denotes a coupler on the molding machine side of the temperature control pipe coupling device which is connected to a coupler on the mold side to connect a pipe for supplying hot water for temperature control and the like. The table 22 is arranged so as to be movable in the radial direction and the vertical direction.

In the present embodiment, as described above, the mold exchanging station S4 arranged between the mold opening station S3 and the mold clamping / injecting station S1 along the rotation direction of the rotary table 22 has the structure shown in FIG. And FIG.
A mold exchanging device 3 as shown in FIG. However, in FIG. 4, the seat surfaces 54 located at the other stations S1 to S3, the injection device 1, the mold clamping device 23, the mold opening device 24, etc. are omitted.

The mold exchanging device 3 is mainly composed of a mold exchanging table 62 which is movably mounted on rails 61, 61 installed on the floor G. The upper surface of the exchange table 62 is substantially flush with the board surface of the rotary table 22, and a pedestal surface 63 on which the die to be exchanged is placed.
It is said that. On this pedestal surface 63, two rows of guide pins 64 lined up toward the rotary table 22 side, respectively.
.. define two-sided pedestals 65, 65 for holding a mold to be exchanged with the mold exchange station S4. In this pedestal 65, the width intervals of the two rows of guide pins 64 ... Are set to be equal to the width intervals of the two rows of guide pins 51 of the seat surface 54. Further, these pedestals 65, 65 are provided with two rows of rollers 66, 65 toward the rotary table 22 side, respectively.
66 are arranged, and a pull pusher 67 is arranged so as to be able to move forward and backward toward the rotary table 22 side.

In this embodiment, the mold M placed on the seat surface 54 and used for injection molding has two molds, an upper mold and a lower mold.
It is divided, and its lower surface is shaped so as to have the same plane shape as the seat surface 54 as shown in FIG. Further, in the mold M, a coupler for connecting a core operating coupler arranged in the mold opening device 24 and an electric contact, and a coupler 58 for connecting a temperature control pipe arranged on the rotary table 22. A coupler and the like connected to the are respectively arranged at appropriate positions. Further, the lower mold of the mold is provided with a supply hole communicating with the air pressure supply device arranged at the mold opening station S3 and an insertion hole through which the hydraulic ejector is inserted. Furthermore, the lower mold of this mold has a pull pusher 67 of the mold exchange table 62.
A hook 68 that is hooked on is attached.

The operation of the rotary injection molding machine configured as described above will be described below with reference to the timetables of FIGS. 5 and 6 and the flowcharts of FIGS. 7 and 8. FIG. 5 shows a unit molding cycle, that is,
It illustrates the movement of each device from the time when the rotary table 22 is stopped in the intermittent rotation to the time when the rotary table 22 is started to rotate next, and the starting point (0) is when the rotary table 22 starts to rotate from the stopped state. There is.

At the injection / mold clamping station S1, while the rotary table 22 is rotating, the screw of the injection device 1 is rotated to measure the resin. After the rotary table 22 is stopped, the pressing device 33 of the mold clamping device 23 is activated to start the descent of the ram 34, the movable plate 35 is brought into contact with the upper mold of the mold M, and then the mold is further clamped to perform the pressing pressure. Boosts. On the other hand, in parallel with this, the nozzle 12 of the injection device 1
Moves forward. Then, with the press pressure increased,
Resin is injected into the mold M and cooled. afterwards,
The nozzle 12 is retracted and the ram 34 of the press device 33 is raised in parallel, and the mold clamping / injection process is completed. Thus, the mold M in which the resin is injected into the cavity inside the mold M
Is sent to the cooling station S2 by intermittent rotation of the rotary table 22, where the resin is cooled,
It is solidified into a molded product, and is further sent to the mold opening station S3 by the intermittent rotation.

On the other hand, at the same time as this mold clamping / injection process,
At the mold opening station S3, a mold opening / mold closing process is performed. FIG. 6 illustrates this in more detail.
However, the operations of the mold clamping device 23 and the injection device 1 in the mold clamping / injecting process are additionally shown in the middle and lower stages of FIG. In the mold opening station S3, after the intermittent rotation of the rotary table 22 is stopped, the lifting hydraulic cylinder 43 operates to lower the support plate 44, and the lower surface thereof is brought into close contact with the upper surface of the upper mold of the mold M. At the same time, the coupler of the hydraulic drive system for core operation and the electrical contact for core operation confirmation on the mold side and the mold opening device 24 side are connected. Next, the clamps 45 attached to the support plate 44 are operated to clamp the upper die, and the core actuating hydraulic drive system is operated to retract the core from the cavity in the die M.

Thereafter, the support plate 44 is lifted by the lifting hydraulic cylinder 43 to lift the clamp 45.
The upper die of the mold M, which is tightly attached to the support plate 44 and is gripped by the support plate 44, also rises together with the support plate 44 and the mold M is opened. When the support plate 44 reaches the upper limit thereof, the fall prevention device 47 is activated, which prevents the support plate 44 and the upper die from falling. Therefore, in this mold open state, the injection molded product is released from the mold M and moved downward by operating the air pressure supply device and the hydraulic ejector arranged below the rotary table 22 in the mold opening station S3. Since it projects from the mold, it is taken out by a handling device such as a robot.
At an appropriate time during this product removal, the air pressure supply device and the hydraulic ejector return to their original state.

When the injection-molded article is taken out in this way, the fall prevention device 47 is released, and then the supporting plate 44 is lowered by the lifting hydraulic cylinder 43 so that the upper die is joined to the lower die and the die M is The mold is closed. Further, by causing the core to project into the cavity in the mold M by the hydraulic drive system, then unraveling the upper mold by the clamp 45 and raising the support plate 44, the mold opening device 24 is returned to the initial state. Return. On the other hand, the mold M from which the injection-molded product is taken out passes through the mold exchanging station S4 by intermittent rotation of the rotary table 22,
It is sent again to the mold clamping / injection station S1 and is used for injection molding in the next molding cycle.

In such a rotary type injection molding machine, when replacing the mold M for which a predetermined molding operation has been completed with a mold M to be used in a new molding operation, the mold shown in the lower part of FIG. 5 is used. According to the process, these molds M are carried out and carried in at the mold changing station S4. However, in the present embodiment, in consideration of the time required for the replacement work and the molding process time in the other stations as described above, this mold replacement process is divided into two processes, that is, a mold carry-out process and a carry-in process. Is going.

FIG. 7 is a flow chart for explaining in detail the unloading process of the mold M in the mold replacement process of the process chart shown in FIG. 5, and the left column shows the operation of the molding apparatus 2. Yes, the center column shows the operation of the hydraulic drive system such as the clamps 52 ..., the lift rollers 55, 55, and the auto coupler 56 on the rotary table 22, and the right column shows the operation of the mold exchanging device 3. It is a thing. Hereinafter, the unloading process of the mold M will be described with reference to FIGS. 5 and 7. However, here, the four molds M respectively mounted on the respective bearing surfaces 54 on the rotary table 22 are referred to as molds M1 to M4, and the mold M1 among them is to be replaced. The seat surface 54 on which the mold M1 is placed is referred to as seat surface 54A.

First, when the molding operation of a predetermined lot by the mold M1 is completed, an instruction to carry out the mold M1 is issued (step S1), and thereby the clamp 52 and the like are prepared (step S2). The mold exchanging table 62 of the mold exchanging device 3 runs (step S3), and one of the two pedestals 65, 65, which is in an empty state, faces the mold exchanging station S4 so as to come to a predetermined position. Stop (step S4). In parallel with this, the rotary table 22 rotates and the mold M1 moves to the mold exchange stage S4.
And is stopped (step S5), and the positioning of the rotary table 22 position is completed (step S6).

On the other hand, in the mold exchanging station S4, when it is confirmed that the seat surface 54A is located at the mold exchanging station S4 (step S7), a signal indicating that the mold is exchanging is sent to the molding apparatus 2 side. The rotation of the rotary table 22 is stopped until the delivery of the mold M1 is completed. Next, the auto coupler 56 operates (step S8), the socket 56B projects toward the rotary table 22 side and is connected to the plug 56A, and the hydraulic drive system for operating the clamp 52 and the lift roller 55 is connected (step S9). ). When the hydraulic drive system is connected in this way, hydraulic oil is supplied to first open the clamps 52 ... (Step S10), and the clamping of the mold M1 by the clamps 52 ... Is released (Step S11). Next, by supplying hydraulic oil to the hydraulic cylinder of the lift roller 55 and raising it (step S12), the mold M1 is placed on the roller mounted on the lift roller 55 and pushed up, and floats from the seat surface 54A. Then, it becomes possible to move in the horizontal direction (step S13).

At the same time, the pull pusher 67 of the mold exchanging table 62 advances toward the rotary table 22 side (step S14), and the hook 68 of the mold M1 is added thereto.
Is locked (step S15), the pull pusher 67 is further retracted (step S16), and the mold M1 is removed from the seat surface 54A. And pull pusher 6
When 7 reaches the retreat limit (step S17), the mold M
The unloading of 1 is confirmed (step S18), and the unloading work in the mold exchanging device 3 ends (step S19).

On the other hand, when the pull pusher 67 retracts and the mold M1 is removed (step S20), the clamp 5
After confirming that 2 ... is opened (step S
21), the socket 56B of the auto coupler 56 is retracted (step S22), the hydraulic drive system is disconnected, and when the socket 56B reaches the retracted limit (step S23), the mold is carried out in these hydraulic drive systems. The work ends (step S24). As a result, the signal during the die replacement is released, the rotary table 22 becomes rotatable, the drive device 28 is operated, and the rotary table 22 is intermittently rotated again (step S).
25). In the present embodiment, as shown in FIG. 5, such a process is set to proceed in parallel with the work process in the other stations S1 to S3 and finish within this process time.

On the other hand, FIG. 8 is a flow chart for explaining in detail the carrying-in process of the mold M in the mold exchanging process of the process diagram shown in FIG. Also in this flowchart,
The left column shows the operation of the molding apparatus 2, the center column shows the operation of the clamp 52, the lift rollers 55, 55, the auto coupler 56 and the like, and the right column shows the operation of the mold exchanging device 3. .. In addition, here, on the seat surface 54A which has been emptied through the above-mentioned carrying-out step, the mold M to be newly molded is provided.
The explanation will be given assuming that 5 is loaded.

First, when an instruction to carry in the die M5 in the next step is issued (step S31), the empty seat surface 54A is placed at the die exchange station S4 by intermittent rotation of the rotary table 22 and stopped. (Step S
32), the rotary table 22 is positioned (step S33). In the hydraulic drive system, when it is confirmed that the seat surface 54A is located at the mold exchanging station S4 (step S34), the auto coupler 56 is coupled (step S35) as in the case of carrying out. In addition,
At the same time, a signal indicating that the mold is being changed is sent to the molding apparatus 2 side, and the rotary table 22 cannot rotate. Next, the clamps 52 ... Are opened and the lift roller 5
When it is confirmed that 5, 55 have risen (step S36), a mold carry-in enable signal is sent to the mold exchanging device 3 (step S37).

On the other hand, in the mold exchanging device 3, the mold exchanging table 6
2 moves one pitch before this signal is output (step S38), and the other pedestal 65, on which the die M5 to be used in the next process is placed, of the two pedestals 65, 65 is exchanged with the die. It is positioned so as to face the station S4 and is stopped (step S39). Then, in response to the above signal, the pull pusher 67 advances and the mold M5 moves to the seat surface 54.
Inserted in A (step S40), pull pusher 6
When 7 reaches the forward limit (step S41),
The hook 68 of the mold M5 is released (step S
42). After that, the pull pusher 67 moves backward (step S43), but stops at the middle position of the movement path without reaching the backward limit (step S44), and with this, the mold in the mold exchanging device 3 concerned. The carrying-in work is completed (step S45).

In parallel with this, in the above hydraulic drive system, when the pull pusher 67 moves forward to load the mold M5, and when the pull pusher 67 reaches the forward limit, the lower mold of the mold M5 moves. One side abuts stoppers 53, 53 projectingly provided on the inner side of the rotary table 22 in plan view, and the mold M5 is positioned on the seat surface 54A (step S).
46). Simultaneously with the charging of the mold M5, the coupler on the mold side is connected to the coupler 53 on the rotary table 22, and thereby the temperature control pipe for supplying hot water for temperature control to the mold M5 is connected. .. Next, the lift roller 55
When the hydraulic pressure for operation is released, the lift roller 55 and the mold M5 descend by their own weight (step S4
7), the lower surface of the lower mold comes into close contact with the seat surface 44A. At the same time, the lower die of the die M5 is locked by the guide pins 51 ... And the stoppers 53 ... to restrain the movement in the horizontal direction, and the clamps 52 ... Are actuated to close the die (Step S48). , Rotary table 2
It is firmly fixed on the second seat surface 54A.

When it is confirmed that the clamps 52 are tightly attached (step S49), the socket 56B is retracted (step S50), the hydraulic coupler system is disconnected by the auto coupler 56, and the socket 56B is closed. It is confirmed that the retreat limit has been reached (step S51), and the die loading process is completed (step S52). At the same time, the signal indicating that the mold is being exchanged, which has been sent to the molding apparatus 2 side, is released, and at the same time, the rotary table 22 becomes rotatable. Then, the rotary table 22 again starts intermittent rotation by the drive device 28 (step S5).
3) The mold M5 placed on the seat surface 54A is sent to the mold clamping / injection stage S1 and narrowed down to the injection molding of the next step (step S54).

As described above, in the rotary type injection molding machine having the above structure, the mold exchanging station S4 is located between the mold opening station S3 and the mold clamping / injection station S1 along the rotation direction of the rotary table 22. .. Therefore, when the mold M1 which has been molded in a predetermined lot as described above is carried out, the mold M1 is moved to the mold opening station S.
Immediately after the injection-molded product is taken out in step 3, it is sent to the mold exchange station S4, and the rotary table 2
It is carried out from the second seat surface 54A. On the other hand, the mold M5 newly carried in the empty seat surface 54A of the rotary table 22 at the mold exchanging station S4 has the mold exchanging station S in the rotating direction of the rotary table 22.
At the mold clamping / injection station S1 located immediately after 4, the mold is immediately clamped and injected for injection molding in the next step.

That is, according to the rotary type injection molding machine having the above-mentioned structure, there is no case where a die which is not used for molding when the die is exchanged is present on the rotary table 22 and wastefully goes around each station. .. For this reason, it is possible to prevent loss of time in the molding cycle, enable efficient molding work, and consequently improve production efficiency. Especially in the recent trend of high-mix low-volume production, it is necessary to change the mold frequently even in such a rotary injection molding machine, but it is necessary to easily and flexibly respond to such requests. Therefore, it is possible to provide an injection molding machine suitable for the above-mentioned small-lot production of various kinds.

Further, in the injection molding machine having the above construction, even when the die replacement is performed in two steps of loading and unloading the die as shown in the above-mentioned flow chart, an empty seat surface is placed on the rotary table 22. 54A is formed by only 1
Only during orbiting. Therefore, even in such a case, it is possible to minimize the occurrence of the seat surface 54 that is not used for molding on the rotary table 22 when exchanging the mold. For example, as in the conventional injection molding machine described above, Even when carrying out and carrying in at the same time, the mold that is not used for molding is rotated more than one revolution, but the loss of the molding cycle can still be suppressed and the production efficiency can be improved. .. Further, as compared with the case where the carry-out and the carry-in are divided into two steps by such a conventional injection molding machine, it is possible to save the molding cycle time of one revolution or more per one die change. It is possible to greatly promote the improvement of molding efficiency.

In the process diagrams and flowcharts shown in FIG. 5 to FIG. 8, in the rotary type injection molding machine of this embodiment, die replacement is performed by carrying out two steps of unloading and loading.
Although only the case of dividing into steps has been described, the present invention is not limited to such a case. It is also possible to carry out the carry-out and carry-in continuously within one molding cycle in consideration of the molding work time at another station and the time required for die replacement.

[0043]

As described above, according to the present invention, four molds are detachably arranged at equal intervals in the circumferential direction on the rotary table which rotates intermittently, and each of the molds is stopped when the intermittent rotation is stopped. A mold clamping / injection station having a mold clamping device and an injection device at a position corresponding to the position of the mold along the rotation direction of the rotary table, a cooling station for holding and cooling the mold, and the mold. Since the mold opening station for opening the mold to take out the injection-molded product and the mold exchanging station equipped with the exchanging device for exchanging the mold are sequentially arranged, they are not used for molding when exchanging the mold. It is possible to prevent the mold from unnecessarily orbiting. That is, the mold after the molding is immediately carried out from the rotary table, and the mold carried into the rotary table is immediately subjected to the injection molding, so that it is possible to improve the production efficiency and It is possible to provide a molding machine adapted for high-mix low-volume production.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a side view of the embodiment shown in FIG.

FIG. 3 is a front view from the mold opening device 24 side of the embodiment shown in FIG.

FIG. 4 is a plan view of the vicinity of the mold exchanging device 3 of the embodiment shown in FIG.

5 is a molding process diagram according to the embodiment shown in FIG. 1. FIG.

FIG. 6 is a process diagram for explaining the details of the process in the mold opening station S3 and the mold clamping / injection station S1 in the process diagram shown in FIG.

FIG. 7 is a flowchart for carrying out a mold by the mold exchanging device 3 shown in FIG.

FIG. 8 is a flow chart for carrying in a mold by the mold exchanging device 3 shown in FIG.

[Explanation of symbols]

 1 Injection Device 2 Molding Device 3 Mold Exchange Device 22 Rotary Table 23 Mold Clamping Device 24 Mold Opening Device 28 Drive Device 51 Guide Pin 52 Clamp 53 Stopper 54 Seat Surface 55 Lift Roller 56 Auto Coupler 62 Mold Exchange Table 65 Pedestal 67 Pull・ Pusher M mold S1 mold clamping / injection station S2 cooling station S3 mold opening station S4 mold changing station

Claims (1)

[Claims] 1. On a rotary table that rotates intermittently, four molds are detachably arranged at equal intervals in the circumferential direction, and at positions corresponding to the positions of the molds when the intermittent rotation is stopped. , A mold clamping / injection station having a mold clamping device and an injection device, a cooling station for holding and cooling the mold, and opening the mold to take out an injection-molded product along the rotation direction of the rotary table. A rotary injection molding machine characterized in that a mold opening station and a mold changing station equipped with a changing device for changing the mold are sequentially arranged.