JPH0123298B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a mold clamping device in a molding device such as an injection molding machine or a casting machine.

BACKGROUND ART Conventionally, mold clamping devices for molds in molding apparatuses have generally been known, such as those using a toggle mechanism or those that are directly pressed by a hydraulic cylinder.

However, with the above toggle mechanism,
While the structure is complex and the equipment is expensive, those using the above-mentioned hydraulic cylinders require a large force to close the mold, so the cylinder is large and the hydraulic flow is large. The drawback was that it took a long time.

The present invention has been made in view of the above problems, and has a simple and inexpensive structure, and can obtain a large mold clamping force with a small driving force.
The object of the present invention is to provide a mold clamping device for a mold that can perform mold clamping and mold clamping release in a short time.

A mold clamping device for a mold according to the present invention includes a fixed mold support member that supports the fixed mold among a fixed mold and a movable mold constituting the mold, is fixed to a fixed platen side, and has an annular outer circumferential surface; a movable support member that supports the movable mold and is fixed to the movable platen side and has a convex fitting portion formed on an annular outer peripheral surface that is substantially the same as the fixed support member;
It is supported rotatably and immovably in the axial direction on the annular outer peripheral surface of the fixed support member, extends from the end face toward the movable mold side in the axial direction, and has a convex fitting portion of the movable support member on the inner peripheral surface. A mold clamping rotary cylinder body having a cylindrical part that forms a recessed fitting part to be screwed together and into which the movable support member is fitted is provided, the convex fitting part of the movable support member and the recess of the rotary cylinder body Grooves of the same width are formed in each of the fitting portions in the axial direction at predetermined angular intervals, and the movable support member and the rotary cylindrical body can be fitted into each groove in the axial direction. , a mold opening/closing drive device for moving the movable plate back and forth in the axial direction, and a mold clamping drive device for rotating the rotary cylinder body, the movable mold support member is fitted with the rotary cylinder body, and the mold clamping drive device The rotary cylinder is rotated to tighten the movable mold support member to the fixed mold support member side, and the mold can be clamped in a short time.When the mold is opened, the rotary cylinder is driven by the auxiliary drive device to tighten the rotary cylinder by a predetermined amount. After rotating,
The rotary cylinder is rotated by the mold clamping drive device, so that the driving force of the mold clamping drive device can be reduced, and the entire device can be miniaturized.

The present invention will be specifically explained below based on illustrated embodiments.

In FIGS. 1 and 2, 1 is an injection device provided in the front of the base 13 in the axial direction, 3 is a fixed plate fixed to the center of the base 13 in the axial direction, and 6 is a movable mold 5b.
A fixed mold support member 4 is rotatable on the annular outer peripheral surface 6a of the fixed mold support member 6, which is fixed to the fixed plate side to support a fixed mold 5a forming the mold 5 and has an annular outer peripheral surface 6a. A rotary cylinder body 20 for mold clamping fitted into the mold clamping cylinder 20 is a mold clamping drive device that rotates the rotary cylinder body 4 .

Further, 14 is a guide member 16, 1 that connects both sides of the bottom plate.
6, a movable plate that fits into the guide grooves 16a, 16a, respectively, and is movable back and forth in the axial direction; 7, which supports the movable mold 5b of the mold 5, is fixed to the movable plate side and supports the fixed mold; A movable support member 17 having an annular outer peripheral surface 7a that is substantially the same as the annular outer peripheral surface 6a of the member 6;
21 is a mold opening/closing cylinder for driving the movable platen that moves the movable platen 14 back and forth by the guide members 16, 16;
This eject device ejects the product from the mold 5 by stretching chains 9, 9 provided on both sides between the eject plates 8 provided on the movable support member 7 and the fixed support member 6.

As shown in FIG. 2, in the injection device 1, the molding material is supplied from the hopper 2, melted and kneaded by the rotation of a built-in screw (not shown), and then fixed through the nozzle 23. Type 5
Cavity 19 of mold 5 consisting of a and movable mold 5b
After injecting the molding material into the mold, the rotary cylinder 4 is rotated by the mold clamping drive device 20 to unclamp the mold 5, and the movable platen 14 is moved backward by the mold opening/closing cylinder 17 for movable platen driving to close the movable mold 5b. The mold 5 is opened by separating it from the fixed mold 5a, and the pair of chains 9, 9 are expanded by the backward movement of the movable plate 14 to advance the eject plate 8, and the eject pins 24, 24 fixed to the eject plate 8 are moved by springs. 25, 25
The product 22 is pushed forward from the fixed die 5a by resisting the force. In addition, the above panel 25
Furthermore, during injection, the eject plate 8 is pressed rearward to prevent the eject pin 24 from entering the cavity 19 of the mold 5.

As shown in FIG. 2, the fixed mold support member 6 has a fixed mold 5a fitted and fixed to the rear thereof, and
The diameter of the front portion is made one step smaller than the annular outer peripheral surface 6a formed at the rear portion, and a stepped wall surface 6b is provided, while the front end is fixed to the fixed platen 3.

On the other hand, the rotating cylindrical body 4 has a flange portion 4a at the front end that fits into the front small diameter portion of the fixed support member 6.
At the same time, a cylindrical portion 4b is provided at the rear portion, which protrudes rearward from the annular outer circumferential surface 6a of the fixed support member 6 and into which the movable support member 7 is fitted. As shown in FIG. 3, the inner circumferential surface of the cylindrical portion 4b includes a female thread portion 4c, that is, a recessed fitting portion formed by at least one female thread, a groove, etc., and a first fan-shaped portion extending in the axial direction. While the concave grooves 4d are alternately formed, a rotational drive threaded portion 4e is formed over a certain range below the outer circumferential surface of the rotary cylinder 4.

On the other hand, the mold clamping drive device 20 for rotating the rotary cylinder 4 has the structure shown below.

A rotary drive rack 10 is provided below the rotary cylinder 4 and is slidably guided by a rack guide member 12 in a direction perpendicular to the axial direction.
0 gear part 10a is connected to the gear part 4e of the rotary cylinder body 4.
It meshes with the On the end face of the rack 10,
The piston rod 11a of the mold clamping cylinder 11 is connected, and the rack 1 is moved by driving the mold clamping cylinder 11.
0 back and forth, the rotary cylinder body 4 is attached to the fixed support member 6.
He is trying to rotate it forward and backward with respect to the annular outer circumferential surface 6a. Note that the rotary cylinder 4 is stopped in the rearward direction by abutting the inner surface of the flange 4a against the step wall surface 6b between the front and rear parts of the fixed support member 6, while in the forward direction the rotary cylinder 4 is held against the stepped wall surface 6b between the front and rear parts of the fixed support member 6. It is held in place by the protruding side portion 12a on the front end side.

Further, the movable mold support member 7 has its rear surface fixed to the movable platen 14 so as not to be rotatable, and the movable mold 5b fitted and fixed to its front part. Movable support member 7
As shown in FIG. 3, the annular outer circumferential surface 7a of
Male threaded portion 7 screwed into female threaded portion 4c of rotary cylinder body 4
b, that is, a convex fitting portion formed by at least one or more male screws, cams, etc., and the second fan-shaped groove 7c are provided alternately, and the male thread portion 7b is inserted into the first fan-shaped groove 4b of the rotary cylinder body 4. After fitting the second fan-shaped grooves 7c into the female screw portions 4c of the rotary cylinder body 4, the rotary cylinder body 4 is rotated by the mold clamping drive device 20, and the male screw portion 7b is screwed into the female screw portion 4c. I try to let them do it. Therefore, the male threaded portion 7
A movable support member 7 having a male threaded portion 7b screwed into the female threaded portion 4c of the rotating cylinder 4 by screwing the female threaded portion 4c with the female threaded portion 4c, and a flange portion 4a of the rotating cylinder 4.
The fixed support member 6 having the stepped wall surface 6b in contact with the inner surface presses against each other, and the movable mold 5b
and the fixed mold 5a are clamped.

Fixed mold 5a, movable mold 5b, movable support member 7,
The fixed support member 6 is provided with a keyway 30a, thereby ensuring the alignment of the mold 5.

In addition, the number of threads of the male thread part and the female thread part in the present invention can be selected as appropriate depending on the required mold clamping force, etc. For example, as shown in FIG.
An inclined cam structure having a concave fitting portion 4'c can also be implemented.

Note that 15 is an ejector cylinder which is operated when ejecting the product 22 from the movable mold side or extracting the movable mold 5b from the movable mold support member 7.

The mold clamping device is provided with an auxiliary drive device as shown in FIGS. 5 and 6. This auxiliary drive device is configured as follows. That is, as shown in FIGS. 5 and 6, a protrusion 4f that protrudes in the radial direction and has a notch 4g is provided on the front end surface of the rotating cylinder 4, and a piston rod 26a is provided on the base 13 in the vertical direction.
A mold opening auxiliary cylinder 26 is provided in which the mold opening auxiliary cylinder 26 moves. On the other hand, a pair of first and second levers 27 and 28, which are symmetrical in the moving direction of the rack 10, are swingably supported at the tip of the piston rod 26a.
The other end of the second lever 28 is pivotally supported on the base side, and a pin 29 is provided at the other end of the second lever 28 so that the lever can move in and out of the notch 4g of the projection 4f, thereby forming a toggle mechanism.
Accordingly, when releasing the mold clamping, the piston rod 26a of the auxiliary cylinder 26 is lowered, and the pin 29 of the second lever 28 presses the notch end surface of the protrusion 4f of the rotary cylinder 4, thereby molding the rotary cylinder 4. The rotating cylinder 4 and the movable support member 7 can be initially separated by rotating in the tightening release direction (indicated by arrow a in the figure). In this way, a large force can be applied to the initial dissociation of the rotating cylinder 4 and the movable support member 7 when the mold clamping is released, and the mold clamping can be released more smoothly. In addition, in FIG. 6, 18 is a rotating cylinder guide bar, 30 is a mold positioning key, and 31
is the ejector chain attachment part.

The molding device having the above structure operates each device according to the operation timing shown in FIG. 4.

That is, first, from the mold open state of the mold 5, the movable platen 14 is advanced by driving the mold opening/closing cylinder 17, and the first fan-shaped groove 4d of the rotary cylinder body 4 is inserted into the male screw portion 7b of the movable mold support member 7. The movable support member 7 is fitted into the rotary cylinder body 4 by fitting the female screw portions 4c into the two fan-shaped grooves 7c, respectively. Thereafter, the rotating cylinder 4 is rotated via the rack 10 by driving the mold clamping cylinder 11, and the male threaded portion 7 of the movable mold support member 7 is rotated.
b is screwed into the female threaded portion 4c of the rotating cylinder 4, and the mold 5 is clamped. After mold clamping, in the injection device 1,
The nozzle 23 is brought into contact with the hot spool 32 by driving the injection touch cylinder, and the molding material is filled into the cavity 19 of the mold 5 through the nozzle 23 and the hot spool 32 by the injection cylinder. After maintaining the injection pressure of the injection cylinder for a predetermined period of time, the injection cylinder is reversely driven and at the same time the screw is rotated to melt and knead the molding material in preparation for the next injection. After that, the nozzle 23 is moved to the hot spool 3 by reverse driving of the injection touch cylinder.
Separate from 2. After the molding material is cooled and solidified in the cavity 19 of the mold 5, first, the auxiliary cylinder 26 of the auxiliary drive device is driven to move the rotary cylinder 4 in the mold clamp release direction via the second lever 28. The rotary cylinder 4 and the movable support member 7 are initially separated by rotation for a certain amount of time. Thereafter, the rotary cylinder 4 is reversely rotated via the rack 10 by reverse driving of the mold clamping cylinder 11, and the male screw portion 7b of the movable support member 7 is again rotated.
By aligning the first fan-shaped groove 4d and the second fan-shaped groove 7c of the rotary cylinder body 4 with the female screw portion 4c, the movable platen 1 is moved by reverse driving of the mold opening/closing cylinder 17 for movable platen driving.
The mold 5 is opened by retracting the mold 4 and separating the movable mold support member 7 from the rotary cylinder 4. and,
After ejecting the product 22 from the fixed mold 5a with the ejector device 21, the above operation is repeated again to perform continuous injection molding.

According to this embodiment, the mold clamping cylinder only needs to rotate the rotary cylinder, so only a small driving force is required, and the cylinder is smaller and requires less hydraulic flow compared to the conventional hydraulic cylinder, compared to a direct clamping system. It's fine. In addition, when opening the mold, a large rotational force is required at the beginning, and once the rotary cylinder 4 starts rotating, a small rotational force is sufficient thereafter. Depending on the device,
Since the rotational force after the initial stage is applied to each rotary cylinder by the mold clamping drive device 20, the driving force of the mold clamping drive device 20 can be reduced.
The entire device can be downsized. Further, since the rotary cylinder body is supported by the fixed support member, the driving force of the movable support member may be small. Furthermore, the rotating cylinder is supported in an axial direction with respect to the fixed support member so as not to be movable, and the convex fitting part of the movable support member is connected to the concave fitting part of the rotating cylinder. By fitting, a large mold clamping force can be obtained even if the driving force of the mold clamping drive device is small. Moreover, according to the above configuration, mold clamping and
Mold clamping can be released in a short time, increasing production efficiency.

Note that the present invention is not limited to this example, and can be implemented in various other ways. for example,
As the mold clamping drive device, a worm may be provided in place of the rack, and the rotating cylinder may be rotated as a worm wheel, and the piston rod of the cylinder can be swung on the protrusion of the rotating cylinder as shown in Fig. 6. It goes without saying that a so-called cam system or the like, in which the rotary cylinder is rotated by being supported by a shaft, may also be used.

As described in detail in the above embodiments, the mold clamping device according to the present invention supports the fixed mold among the fixed mold and the movable mold constituting the mold, is fixed to the fixed plate side, and has an annular outer periphery. a fixed type support member having a surface, a movable type support member that supports the movable type and is fixed to the movable platen side and has a convex fitting portion formed on an annular outer peripheral surface that is substantially the same as the fixed type support member; It is supported rotatably and immovably in the axial direction on the annular outer peripheral surface of the fixed support member, extends from the end face toward the movable mold side in the axial direction, and has a convex fitting portion on the inner peripheral surface of the movable support member. A mold clamping rotary cylinder body having a cylindrical part that forms a recessed fitting part to be screwed together and into which the movable support member is fitted is provided, the convex fitting part of the movable support member and the recess of the rotary cylinder body Grooves of the same width are formed in the axial direction at predetermined angular intervals in each of the fitting portions, and the movable support member and the rotating cylinder can be fitted into each groove in the axial direction. , a mold opening/closing drive device for moving the movable plate back and forth in the axial direction, and a mold clamping drive device for rotating the rotary cylinder body, the movable mold support member is fitted into the rotary cylinder body, and the mold clamping drive device Since the mold is clamped by rotating the rotary cylinder and tightening the movable support member toward the fixed support member, the structure is simple and inexpensive, and the mold clamping and Mold clamping can be released in a short time, increasing production efficiency. In addition, when opening the mold, a large driving force is required to rotate the rotating cylinder, but after the rotating cylinder is rotated by a predetermined amount by the drive of the auxiliary drive device, the rotating cylinder is rotated by the mold clamping drive device. Since the mold clamping drive device rotates, the driving force of the mold clamping drive device can be small, and the entire device can be downsized. Further, since the rotary cylinder body is supported by the fixed support member, the driving force of the movable support member may be small. In addition, even if the driving force of the mold clamping drive device is small, it can be increased by screwing the rotary cylinder and the movable support member together and supporting the rotary cylinder against the fixed support member so that it cannot move freely in the axial direction. Since mold clamping force can be obtained and the mold clamping drive device does not require a very large driving force, the device can be downsized.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of an injection molding machine equipped with a mold clamping device according to an embodiment of the present invention, FIG. 2 is a partial longitudinal sectional view of FIG. 1, and FIG. 4 is an explanatory diagram showing the operation timing of the injection molding machine shown in FIG. 1, and FIG. 5 is a plan view of the main part showing the vicinity of the auxiliary drive device of the above embodiment. , FIG. 6 is a sectional view taken along the line -- in FIG. 5, and FIG. 7 is a perspective view showing another embodiment. 3... Fixed plate, 4... Rotating cylindrical body, 4b... Cylindrical part, 4c... Female threaded part, 4d... First fan-shaped groove,
5... Mold, 5a... Fixed mold, 5b... Movable mold,
6... Fixed support member, 7... Movable support member,
7b...Male thread part, 7c...Second fan-shaped groove, 14
...Movable plate, 17...Mold opening/closing cylinder, 19...
Cavity, 20...Mold clamping drive device.

Claims (1)

[Claims] 1. A mold 5 consisting of a fixed mold 5a and a movable mold 5b that moves back and forth in the axial direction with respect to the fixed mold 5a, and forming a cavity 19 by aligning the movable mold 5b with the fixed mold 5a. In a molding device that performs molding by filling molding material into the cavity 19 in a mold clamped state, a fixed mold support member 6 is fixed to the fixed platen 3 side supporting the fixed mold 5a and has an annular outer circumferential surface 6a.
and a movable support member 7 that supports the movable mold 5b and is fixed to the movable platen 14 side, and has convex fitting portions 7b and 7'b formed on an annular outer peripheral surface 7a that is substantially the same as the fixed support member 6. A movable support member is rotatably supported on the annular outer circumferential surface 6a of the fixed support member 6 but not movable in the axial direction, and extends from the end face toward the movable mold 5b in the axial direction. 7, a concave fitting portion 4c screwed into the convex fitting portions 7b, 7'b,
4'c and a mold clamping rotary cylinder 4 having a cylindrical part 4b into which the movable support member 7 is fitted, and the movable support member 7 has convex fitting parts 7b, 7'b
Grooves 7c and 4d of the same width are formed in the axial direction at predetermined angular intervals in the recessed fitting portions 4c and 4'c of the rotating cylinder 4, respectively, and movable support is provided for each of the grooves 7c and 4d. A mold opening/closing drive device 17 that allows the member and the rotary cylinder to fit into each other in the axial direction, and moves the movable platen 14 back and forth in the axial direction, and a mold clamping drive device 20 that rotates the rotary cylinder 4. The movable support member 7 is fitted to the rotating cylinder 4, and the mold clamping drive device 20 rotates the rotary cylinder 4 to tighten the movable support member 7 to the fixed support member 6 side. A mold clamping device characterized in that auxiliary drive devices 26, 27, and 28 are provided to clamp the mold 5 and rotate the rotary cylinder 4 by a predetermined amount when the mold 5 is opened. Device.