JP3209586B2 - Injection molding die and injection molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection mold and an injection molding method for molding a thick molded product with high precision.

[0002]

2. Description of the Related Art When injection molding a thick product such as a plastic lens, there is a problem that the molding cycle time becomes long because cooling is required to prevent sinking and deformation.
As a method for solving this problem, a method disclosed in Japanese Patent Application Laid-Open No.
The injection molding method described in Japanese Patent Publication No. 1 is known. In this injection molding method, the cavity unit is clamped by a U-shaped mold clamping member, and the mold unit is heated to a temperature equal to or higher than the glass transition point to inject the molten resin. Slowly cool to temperature, then
The mold is released from the mold clamping mechanism of the molding machine while the mold clamping of the cavity unit is held by itself, and the cavity unit is cooled independently.

[0003]

However, in the conventional method, since the mold clamping is self-maintained only by the elastic deformation force of the U-shaped mold clamping member, there is a disadvantage that the entire apparatus becomes large and complicated. Was. In addition, it is necessary to manually insert or remove the U-shaped mold clamping member, or use another actuator, which is a problem in promoting automation. That is, the conventional injection molding method aims at shortening the molding cycle time by temporarily isolating the cavity unit from the mold clamping mechanism of the molding machine in the cooling step, and setting and injecting another cavity unit in the meantime. If the size of the cavity unit is increased or automation cannot be achieved, it takes time to move, replace, and attach / detach the cavity unit, so that the original purpose cannot be achieved. The present invention
In view of such problems, it is possible to securely hold the mold clamping force with an extremely small mold clamping member, and to enable self-holding and releasing of the mold clamping force by a simple mechanism, thereby achieving automation. An object of the present invention is to provide an injection mold and an injection molding method that can be easily achieved.

[0004]

According to the present invention, there is provided an injection molding die according to the present invention, in which two or more cavity units of a pair of cavity units forming a cavity are mounted and a direction perpendicular to a mold opening direction is provided. And a slide plate that slides between the pair of cavity units,
A holding member to which the other cavity unit is detachably attached, a hook member attached to each of the one cavity unit and the holding member, and a movable member attached to the other cavity unit so as to be movable in a direction orthogonal to the mold opening direction. A lock member alternately and detachably engaged with the hook member of the one cavity unit and the hook member of the holding member; and the lock member and the hook member of the one cavity unit provided inside the other cavity unit. And an elastic member for self-holding the mold clamping force at the time of engagement. In addition, the injection mold of the present invention has one cavity unit, the other cavity unit that forms a cavity when one surface comes into close contact with the one cavity unit, and the one cavity unit that comes into close contact with the other cavity unit. An elastic member that urges the contact surface so that the contact surfaces are in close contact with each other; and a holding member to which the other cavity unit is detachably attached. The other cavity unit is disposed between the one cavity unit and the holding member. The other cavity unit is provided with switching means so that it can be selectively switched and held in each other, and one of the one cavity unit and the holding member is switched to the switching means by switching the switching means. A locking means is provided to be engaged and the other is opened, and the The resin is injected in a state where one cavity unit and the other cavity unit are in close contact with each other to form a cavity, and at the same time, the elastic member is urged in a direction in which the contact surfaces are in close contact with each other. When the switching means of the other cavity unit is engaged, the one cavity unit and the other cavity unit are in a self-holding state, and the locking means of the holding member and the switching means of the other cavity unit are opened when the mold is opened. Are engaged so that one cavity unit and the other cavity unit are opened. In addition, in the injection molding method of the present invention, two or more slide units on the movable platen side of the injection molding machine are mounted in parallel with the pair of cavity units forming the cavities being self-held, and the slide plate is slid. After one cavity unit is opposed to a holding member attached to the fixed side platen side of the injection molding machine, the movable platen is advanced in a mold clamping direction, and one surface of the other cavity unit in the pair of cavity units is The other cavity unit and the one cavity unit constituting the cavity unit were held in contact with a holding member, and were self-held. The locking means provided on one cavity unit and the other cavity unit were provided on the other cavity unit. The state of engagement with the switching means is released by the operation of the switching means. By the operation of the switching means, the switching means is engaged with the locking means provided on the holding member to hold the other cavity unit on the holding member, and then the movable side platen is moved in the mold opening direction. After retracting, the contact surface between the other cavity unit and the one cavity unit is separated, and after taking out the resin molded product from the cavity, the movable side platen is advanced again in the mold clamping direction, so that one cavity unit and the other cavity unit are moved forward. The unit is brought into close contact, resin is injected into the cavity formed by the close contact, and the engagement between the switching means and the locking means of the holding member is released by the operation of the switching means provided in the other cavity unit. The switching means into engagement with the locking means of one of the cavity units, Is retracted in the mold opening direction to self-hold the one cavity unit and the other cavity unit, release the pair of cavity units from the holding member, and then slide the cavity unit from the position facing the holding member. The slide member is slid by the plate, and another pair of cavity units attached to the slide plate is opposed to the holding member.

[0005]

In the injection molding die having the above structure, the hook member and the lock member of one of the cavity units are engaged with each other when the mold is clamped, so that the pair of cavity units are brought into close contact with each other. At this time, since the self-holding of the mold clamping force is performed by the urging force of the elastic member, the mold clamping force can be reliably held. On the other hand, when the lock member engages with the hook member of the holding member, the pair of cavity units can be opened to release the molded product. Therefore, the self-holding and release of the mold clamping force can be automatically performed in conjunction with the mold clamping operation and the mold opening operation. Also, in the injection mold having the above configuration, the locking means of one cavity unit and the switching means of the other cavity unit are engaged with each other, and the contact surfaces of the pair of cavity units are brought into close contact by the bias of the elastic member. As a result, the self-holding of the mold clamping force can be ensured, and even when the molded product is taken out, one of the cavity units and the other cavity unit can be opened by switching the switching means. . Therefore, the self-holding and release of the pair of cavity units is facilitated in conjunction with the switching of the switching means.
Further, in the above-described injection molding method, the switching means of the switching means provided in the other cavity unit selectively switches the operating switching means with respect to the locking means of one cavity unit or the locking means of the holding member. Since it is possible to automatically switch and disengage, the self-holding and release of the pair of cavity units can be automated.

[0006]

FIG. 1 to FIG. 3 show a first embodiment of the present invention, in which a movable cavity unit 1 serving as a pair of cavity units and a fixed cavity unit 2 are brought into close contact with each other to form a cavity 29 for molding. It is supposed to be. In FIG. 1, the movable-side cavity unit 1 is mounted on a slide plate 13 slidable in the vertical direction in FIG. 1, while the fixed-side cavity unit 2 is connected to a fixed-side holding plate 4 as a holding member by a hook member as locking means. 3 (which will be described later) so that it can be detachably attached. The slide plate 13 is slidably attached to a movable-side attachment plate 14 attached to a movable-side platen 15. The sliding direction of the slide plate 13 is performed in a direction orthogonal to the mold opening direction. To perform the slide, an actuator 16 supported by the movable side mounting plate 14 is connected to the slide plate 13. In this case, a dovetail-shaped groove portion 14a is formed in the movable-side mounting plate 14, and the slide plate 13
Has a protrusion 13a inserted into the groove 14a, so that the slide of the slide plate 13 is guided. Such a slide plate 13 has a plurality (2 in the illustrated example).
The movable side cavity units 1 are mounted side by side, and the fixed side holding plate 4 of the cavity units 1
(Holding member) is switched.

The fixed-side cavity unit 2 includes a fixed-side mold plate 5 that is in close contact with the movable-side cavity unit 1, and first and second fixed-side mounting plates 9 and 10, and a second fixed-side mounting plate. Reference numeral 10 is removably attached to the fixed-side platen 17 via a fixed-side holding plate 4 as a holding member attached to the fixed-side platen 17. When the movable-side cavity unit 1 and the fixed-side cavity unit 2 come into close contact with each other to form a pair of cavity units between the fixed-side mold plate 5 and the first fixed-side mounting plate 9, the self-clamping force is reduced. A spring 25 is provided as an elastic member for holding. The fixed-side template 5 is urged in the direction of the movable-side cavity unit 1 by the spring 25, which causes a gap between the fixed-side template 5 and the first fixed-side mounting plate 9. The amount of movement by the force is regulated by the top pin 24 (see FIG. 3).

First and second fixed side mounting plates 9 and 10
Are attached so as to have a predetermined gap by stop pins 26 (only one is shown in the figure as a representative) interposed between these mounting plates 9 and 10. A plate-like lock member 11 is slidably inserted into the gap. The lock member 11 has three convex portions 11a having a dimension T and two concave portions 11b having a dimension H alternately formed at both upper and lower ends thereof (see FIG. 2). As described later, when the movable-side cavity unit 1 and the fixed-side cavity unit 2 come into close contact with each other, the protrusions 11a and the recesses 11b interlock the self-holding of the mold-clamped state and the release thereof with the mold-clamp and mold-opening. It is intended to switch over. 8 is a lock member 1 as such switching means.
1 is an actuator that slides in a direction orthogonal to the mold opening direction. In the illustrated example, the actuator is fixed to an end surface of a first fixed-side mounting plate 9 via a support member 8a, and a protruding rod 8b of the actuator 8 Is connected to the end face of the lock member 11. Reference numeral 40 denotes a resin injection nozzle, and reference numeral 4a denotes an escape hole formed in the fixed-side holding plate 4 so that the nozzle 40 advances.

In addition to the above configuration, the fixed platen 17
Fixed holding plate 4 and movable platen 1 attached to
Hook members 3 and 12 are attached to the movable-side cavity unit 1 disposed on the fifth side (see FIG. 1). The hook member 3 of the fixed side holding plate 4 is fixed to the upper end surface (the lower end side is not shown) of the holding plate 4. As shown in FIG. 1, the hook member 3 has two hook pieces 3a extending in the mold opening direction and having a distal end bent in an L shape.
One hook 3a is provided between the hook pieces 3a, and the hook pieces 3a and the slits 3b engage and disengage with the protrusions 11a and the recesses 11b of the lock member 11, thereby fixing the lock member 11. The connection and detachment of the side holding plate 4 and the fixed side cavity unit 2 are performed.

[0010] Hook members 12 as locking means in the movable side cavity unit 1 are fixed to the upper end surface and the lower end surface of two movable side cavity units 1 arranged side by side, respectively. At the distal end of each hook member 3, there are three hook pieces 12a whose distal side is bent into an L shape with a dimension somewhat larger than the dimension T of the convex portion 11a of the lock member 11,
Two slits 12b having a size somewhat larger than the size H of the concave portion 11b of the lock member 11 are formed alternately, and engagement and disengagement with the lock member 11 are performed by the hook pieces 12a and the slits 12b. The coupling and disengagement of the movable side cavity unit 1 and the fixed side cavity unit 2 are performed. When one of the pair of cavity units is attached to the slide plate 13 as one unit, the movable-side cavity unit 1 and the fixed-side cavity unit 2 forming the pair of cavity units serve as the upper mold in FIG. As shown, hook member 1
1 and the lock member 11 are engaged.

Next, the operation of this embodiment will be described. When one of the two cavity units is in the interlocked position with the nozzle 40, the movable platen 15 is moved forward to the fixed platen 17 to perform mold clamping. At the time of this mold clamping, the hook piece 12a of the hook member 12 of the movable side cavity unit 1 is
And the hook piece 3a of the hook member 3 is located within the slit 12b of the hook member 12, so that the lock member 11 can slide between the hook pieces 12a, 3a. (In the following description, the lock member 11 can be slid between the hook pieces 12a and 3a in the same manner at the time of mold clamping.) In this mold clamping state, the molten resin is injected into the cavity 29. After the holding pressure after the injection is removed, the lock member 11 is moved in the mold opening direction by the actuator 8 so that the convex portion 11a is formed in the hook piece 12a of the hook member 12 of the movable side cavity unit 1 and the concave portion 11b is formed in the slit. 12b. This allows
The hook member 12 and the lock member 11 of the movable side cavity unit 1 are engaged. (In this operation, since the resin is first injected into the cavity 29 formed by the pair of cavity units, the hook member 12 and the lock member 11 Actuator 98 is actuated assuming that the engagement position has moved from the normal position.)

When the movable side platen 15 is retracted in this state, the movable side cavity unit 1 and the fixed side cavity unit 2 move together with the movable side platen 15 (the two cavity units in FIG. 1). Inside the upper cavity unit). At this time, the biasing force of the spring 25 presses the fixed mold plate 5 in the direction of the movable cavity unit 1, so that the parting line surface is closed and the mold clamping force is self-held. After the movable platen 15 is retracted, the actuator 16 is driven to slide the slide plate 13 until the other pair of cavity units reach the position communicating with the nozzle 40. Then, as described above, the movable platen 15 is moved forward to the fixed-side platen 17 side to perform mold clamping, injection, and the hook member 12 and the lock member 11 of the pair of cavity units are engaged by the actuator 8. After retracting the movable platen 15,
By driving the actuator 16 again, the slide plate 13 is slid until the initial cavity unit in the self-holding state reaches the position for communicating with the nozzle 40.

After this slide, the movable side platen 15 is advanced to perform mold clamping of the initial cavity unit, and in this state, the actuator 8 locks the lock member 11.
To move. This movement is performed by the hook piece 1 of the hook member 12.
The concave portion 11b of the lock member 11 is located at the position 2a, the convex portion 11a is located at the position of the slit 12b, and the convex portion 11a of the lock member 11 is the position of the hook piece 3a of the hook member 3 of the fixed holding plate 4. Perform so that it is located in. As a result, when the movable side cavity unit 1 and the fixed side cavity unit 2 are separated from each other, the engagement between the hook member 12 and the lock member 11 of the movable side cavity unit 1 is released, and the hook member 3 and the lock member 11
Are engaged, and the fixed side cavity unit 2 and the fixed side holding plate 4 are engaged. Therefore, when the movable platen 15 is retracted, the movable cavity unit 1 and the fixed cavity unit 2 are separated from each other, and
The parting line between them opens, and the molded product is taken out. Then, the movable side platen 15 is advanced again to close the mold, the molten resin is injected, and the lock member 11 is moved by the actuator 8, and the hook pieces 12 a of the hook member 12 of the movable side cavity unit 1 and the protrusions of the lock member 11 are formed. After the movable side platen 15 is retracted, the actuator 16 is driven to slide the slide plate 13, and the cavity unit ejected for the second time is moved to the communication position with the nozzle 40. . Then, the movable platen 15 is advanced again to
The cavity unit injected at the second time is clamped, and the lock member 11 is moved in the same manner as described above, so that the movable side cavity unit 1 and the fixed side cavity unit 2 are moved.
Is released, the fixed-side cavity unit 2 and the fixed-side holding plate 4 are brought into the engaged state, and the mold is opened and the molded product is taken out. Thereafter, by repeating these steps, injection molding is performed on the cavity units alternately.

In such an embodiment, even when the resin internal pressure acts on the hook member 12 when the mold clamping force of the pair of cavity units 1 and 2 is self-held, the compressive force of the spring 25 is applied to the PL surface (partition). PL)
The face never opens. In addition, since the actuator 8 is linked with the mold clamping operation, the self-holding of the mold clamping force of the cavity units 1 and 2 can be turned ON / OFF, and automation can be performed. Moreover, ON / OFF of self-holding and ON / OFF of holding of the cavity unit by the fixed-side holding plate 4.
And are simultaneously switched by the mold clamping operation, so that there is no malfunction and damage to the mold based on the malfunction can be prevented. In this case, by reducing the pitch between the convex portion 11a and the concave portion 11b of the lock member 11, the self-holding ON / OFF switching stroke can be reduced.

[0015]

Second Embodiment FIG. 4 shows a second embodiment of the present invention.
The same elements as those described above are denoted by the same reference numerals and correspond to each other.
In this embodiment, the first and second fixed side mounting plates 9, 10
A connecting rod 20 that bends and extends in the direction of the fixed platen 17 is attached to the end face of the lock member 11 interposed therebetween (that is, the connecting rod 20 extends in the mold opening direction). A protruding rod 21 is provided on an end surface of the fixed-side holding plate 4 corresponding to the connecting rod 20. The protruding rod 21 has an insertion hole 21 a and is in a state of being attached to the output end of the actuator 8.

In the above structure, when the mold is clamped by making the insertion hole 21a of the protruding rod 21 correspond to the tip end 20a of the connecting rod 20, the connecting rod 2
0 projects and enters the insertion hole 21a of the rod 21. By driving the actuator 8 in this state, the lock member 11 moves up and down (as shown in FIG. 4) to engage with the hook member 12 of the movable cavity unit 1 or the hook member 3 of the fixed side holding plate 4 or Withdrawal takes place. Therefore, in this embodiment, the single actuator 8 attached to the fixed side holding plate 4 as a holding member corresponds to a plurality of fixed side cavity units in a plurality of cavity units slid by the slide plate 13, Since the movement of the lock member 11 for self-holding and releasing the mold clamping force is performed by a single actuator 8, the number of parts is reduced, the configuration and assembly are simple, and the control is easy.

[0017]

As described above, the injection mold of the present invention
Even if a force in the extension direction acts on the hook member holding the mold clamping state due to the internal resin pressure, the parting line surface does not open because the elastic member urges the pair of cavity units in the mold clamping direction. For this reason, even if it is small,
The self-holding of the mold clamping force can be reliably performed. Further, the movement of the lock member can be linked to the mold clamping and mold opening, whereby the self-holding and releasing of the mold clamping force can be automated, and the molding cycle time can be shortened. Further, in the injection molding die of the present invention, even if a force in the extension direction due to the internal resin pressure acts on the locking means for holding the mold clamped state, the elastic member is moved in the direction in which the contact surfaces of the pair of cavity units are in close contact with each other. Since the parting line surface does not open due to the urging, and the switching operation of the locking means can be linked with the mold clamping and mold opening, the self-holding and releasing of the mold clamping force can be automated. Further, according to the injection molding method of the present invention, by the switching operation of the switching means provided in the other cavity unit, the switching means operated by the switching means of the one cavity unit or the locking means of the holding member is selectively applied. It is possible to automatically switch between the two and make it detachable, so that it is possible to maintain the self-holding state of the pair of cavity units and automate the release thereof,
The molding cycle time can be shortened.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is a partial perspective view of the fixed side cavity unit of FIG. 1;

FIG. 3 is a cross-sectional view of a fixed-side cavity unit and a fixed-side holding plate (holding member).

FIG. 4 is a sectional view of a second embodiment.

[Explanation of symbols]

 Reference Signs List 1 movable side cavity unit 2 fixed side cavity unit 3 hook member 4 holding plate 9 lock member 12 hook member 13 slide plate

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuo Suga 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Inventor Kazuo Saito 2-43-2 Hatagaya, Shibuya-ku, Tokyo In Olympus Optical Co., Ltd. (72) Inventor Shozo Nishida 1-6-1-1, Funakoshi Minami, Aki-ku, Hiroshima-shi, Hiroshima Japan Steel Works Co., Ltd. (56) References JP-A-4-115911 (JP, A) 58-175024 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45/00-45/68

Claims (3)

(57) [Claims] 1. A slide plate to which two or more of one cavity unit among a pair of cavity units forming a cavity is attached and slides in a direction orthogonal to a mold opening direction, and the other cavity among the pair of cavity units A holding member to which the unit is detachably attached, a hook member attached to each of the one cavity unit and the holding member, and the one of the one cavity unit movably attached to the other cavity unit in a direction orthogonal to a mold opening direction. A lock member alternately and detachably engaged with a hook member of the cavity unit and a hook member of the holding member; and engagement of the lock member provided inside the other cavity unit with the hook member of one cavity unit. Elastic member that retains the mold clamping force at the time of operation An injection molding die comprising: 2. One of the cavity units, the other cavity unit forming a cavity when one surface is in close contact with the one cavity unit, and the contact surface is in close contact when the one and the other cavity units are in close contact. And a holding member to which the other cavity unit is detachably attached. The other cavity unit is selectively provided between the one cavity unit and the holding member. The other cavity unit is provided with switching means so as to be able to switch and hold each other, and one of the cavity units and the holding member is engaged with the switching means by switching the switching means. A locking means is provided so that the other is open, and the one cap is closed when the mold is clamped. The resin is injected in a state where the cavity unit is in close contact with the tee unit and the cavity is formed, and the elastic member is urged in a direction in which the contact surface is in close contact with the cavity unit. And the other cavity unit is in a self-holding state, and the locking means of the holding member and the switching means of the other cavity unit are engaged when the mold is opened. An injection mold, wherein one cavity unit and the other cavity unit are in a mold open state. 3. A pair of cavity units forming a cavity are mounted in parallel on a slide plate on a movable platen side of an injection molding machine while holding a pair of cavity units, and the slide plate is slid and moved to form one cavity unit. After moving the movable platen forward in the mold clamping direction after facing the holding member attached to the fixed side platen side of the injection molding machine, one surface of the other cavity unit in the pair of cavity units abuts on the holding member. And the self-holding of the other cavity unit and the one cavity unit constituting the cavity unit, the engagement between the locking means provided on one cavity unit and the switching means provided on the other cavity unit. The switching state is released by the operation of the switching means, and By operation, the switching means is engaged with the locking means provided on the holding member to hold the other cavity unit on the holding member. Then, the movable platen is retracted in the mold opening direction and The contact surface between the cavity unit and one cavity unit is separated, and after taking out the resin molded product from the cavity, the movable side platen is advanced again in the mold clamping direction to bring the one cavity unit into close contact with the other cavity unit. The resin is injected into the cavity formed by the close contact, and the switching means provided in the other cavity unit is actuated to release the engagement state between the switching means and the locking means of the holding member to thereby switch the switching means. Is engaged with the locking means of one of the cavity units, and then the movable side platen is opened in the mold opening direction. To allow the one cavity unit and the other cavity unit to self-hold, and to release the pair of cavity units from the holding member. Then, the cavity unit is slid by the slide plate from a position facing the holding member. And a pair of cavity units attached to the slide plate are opposed to the holding member.