JPH10291240A - Mold clamping device for vertical type injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the structure and replace a screw mechanism easily. SOLUTION: In a mold clamping device of a vertical type injection molding machine, when a driving motor 27 is actuated in the mold opening state, a screw shaft 22 is rotated and a nut component 21 is lowered together with a cross head 20, by which a toggle mechanism 11 is stretched to lower an end plate 5 and carry out the mold clamping downward movement of a movable platen 3. The driving motor 27 and a transmission mechanism 30 can be fixed on the given positions to simplify the structure. Also as the outer diameter of the nut component 21 is formed smaller than the inner diameter of a through hole 2a in which a bearing housing 34 is fitted and a screw mechanism 31 can be drawn out on a fixed platen 2, it is not required to dismantle the toggle mechanism 11 or remove the fixed platen 2 and a rotary table 35 at the time of replacing the screw mechanism 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping device for moving a movable plate with respect to a fixed plate in a vertical injection molding machine.

[0002]

2. Description of the Related Art As a mold clamping device of an electric vertical injection molding machine,
The one shown in FIG. 5 has been proposed (JP-A-5-2008)
No. 13). To explain this, the movable platen 3 is provided above the fixed platen 2 fixed to the machine body 1 with a tie bar 4.
The end plate 5 is fixed to the lower end of the tie bar 4 and fixed to the lower end of the tie bar 4 so as to move up and down with respect to the fixed platen 2 together with the movable platen 3. I have.

[0003] The fixed platen 2 and the end plate 5
A pair of toggle links 41, 42 are pivoted 43, 44, respectively.
Is mounted so that it can be turned up and down freely.
5 are connected to each other so as to be able to flex vertically. The toggle links 42, 42 have a bell crank shape and have nut members 46a, 46b at the lower ends. Nut member 46
a and 46b are mutually reverse-threaded, and are screwed to the mutually reversely-threaded screw portions 47a and 47b of the horizontal screw shaft 47, respectively.

The screw shaft 47 is rotatable in the circumferential direction, and is connected to a drive motor 48 via a required transmission mechanism 49. The screw shaft 47 is vertically supported by a transmission mechanism 49, and a drive motor 48 is provided on a guide table 50 so as to be movable in a direction perpendicular to the plane of FIG. Dies 7 and 8 are attached to the fixed platen 2 and the movable platen 3. Reference numeral 9 denotes an injection device.

In the above-described mold clamping device of the electric vertical injection molding machine, when the screw shaft 47 is rotated by the operation of the drive motor 48 to move the nut members 46a, 46b away from each other, the toggle links 41, 42 are provided. Is extended linearly to lower the end plate 5, so that the movable platen 3 moves downward in the mold clamping and molds 7 and 8 are clamped between the movable platen 3 and the fixed platen 2. At this time, the screw shaft 47 descends with the rotation of the toggle links 42, and the drive motor 48 moves on the guide table 50 as the screw shaft 47 descends.

[0006]

The above-described mold clamping device of the vertical injection molding machine can eliminate the unbalanced load generated when the drive motor 48 is directly connected to one end of the screw shaft 47 so as to be freely movable up and down. Since the transmission mechanism 49 and the like must be moved following the vertical movement of the screw shaft 47, the structure becomes complicated. Further, since it is structurally difficult to increase the rotation angle of the bell crank-shaped toggle link 42, there is also a complaint that the opening and closing stroke of the movable platen 3 cannot be increased.

An object of the present invention is to provide a mold clamping device for a vertical injection molding machine which has a simple structure and allows easy replacement of a screw mechanism. Another object of the present invention is to provide a mold clamping device for a vertical injection molding machine that can increase the opening and closing stroke of a movable plate.

[0008]

In order to achieve at least one of the above-mentioned objects, according to the present invention, a movable plate is fixed to an upper end of a tie bar above a fixed plate fixed to a machine body. In the vertical injection molding machine, which is provided below and below the fixed plate, an end plate is fixed to a lower end of the tie bar and is provided up and down with respect to the fixed plate together with the movable plate. Under the board, a screw shaft is supported at the upper end thereof on a bearing of a bearing housing which is removably fitted above the through hole of the fixed board, and the lower end is supported on a bearing of the machine body or the fixed board. Provided
The screw shaft has an outer diameter smaller than the inner diameter of the through hole, and a nut member for vertically moving the end plate together with the movable plate by vertical movement along the screw shaft is screwed into the screw shaft. A drive motor for rotating the screw shaft to move the nut member up and down is connected.

In the above means, when it becomes necessary to remove the screw mechanism from the fixed platen or the like, for example, after removing the nut member from the crosshead, the lower end of the bearing housing and the screw shaft are separated from the fixed platen and the bearing. Pull it up, lift the screw mechanism together with the bearing housing and remove it on the fixed platen. At this time, since the outer diameter of the nut member is smaller than the inner diameter of the through hole of the fixed plate, and the nut member can be passed through the through hole, the screw mechanism can be removed while the nut member is screwed onto the screw shaft. it can. To mount the screw mechanism on a fixed platen or the like, reverse the above operation.

[0010] In the above-mentioned mold clamping device of the vertical injection molding machine, it is preferable that the screw mechanism has a ball screw structure or a roller screw structure (claim 9). In this case, the movable plate is smoothly opened and closed. be able to.

In a rotary type vertical injection molding machine in which a rotary table is rotatably provided on a fixed board, an extraction hole of a bearing housing is formed in the rotary table. In this means, a removal hole formed in the rotary table is used for removing and mounting the screw mechanism. A lid is preferably provided in the extraction hole so as to be detachable.

In the above-mentioned mold clamping device, the toggle link is connected between the fixed plate and the end plate by a toggle pin so as to be able to bend up and down freely by a toggle pin. A toggle mechanism for extending the movable platen by moving it up and down to close the mold.
The crosshead may be detachably connected to a nut member screwed to the screw shaft above the end plate (claim 3), and the toggle mechanism may be provided below the end plate with a screw shaft. The crosshead may be detachably connected to a nut member screwed into the end plate, and a through-hole through which the nut member can pass may be formed in the end plate. According to this means, the boosting function of the toggle mechanism can be utilized.
In the case of the configuration described in claim 4, the nut member is passed through the through hole when removing the screw mechanism or the like. By this means, the height of the mold clamping device can be reduced.

The toggle link of the toggle mechanism may be configured to extend by moving the toggle pin closer to the screw shaft (claim 5), and the toggle link may be configured to extend by moving the toggle pin away from the screw shaft. (Claim 6).

Further, the toggle piece of the toggle mechanism may be connected to a free end opposite to the toggle pin of the toggle link pivotally attached to the end plate by a connecting pin (claim 7). Alternatively, a configuration may be employed in which a connecting pin is connected to an intermediate portion of a toggle link that is pivotally attached to the fixed board side by a pivot (claim 8). It is also possible to adopt a structure that does not use a toggle mechanism.

[0015]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.
In addition, the fixed platen 2, the movable platen 3, the end plate 5, etc.
Since the basic configuration of the main part of the vertical injection molding machine is the same as that of FIG. 5, the same reference numerals are given and the detailed description is omitted.
In FIG. 1, the left half shows the mold open state, and the right half shows the mold clamped state. This point is the same in other FIGS. 2 to 4.

In FIG. 1, reference numeral 11 denotes a toggle mechanism. The toggle mechanism 11 is attached to the lower surface of the fixed platen 2 so as to be vertically rotatable about a pivot 12, and is attached to the upper surface of the end plate 5 so as to be vertically rotatable about a pivot 14. Toggle pin 1 on toggle link 13
The toggle links 16, 16 connected by 5 and the mounting shaft 17
And a crosshead 20 connected to the other end of the toggle link 16 by a connecting pin 19. Left and right two sets of toggle links 13, 1
6 can bend up and down. The pivot 14 of the end plate 5 is provided directly below the pivot 12 of the fixed platen 2.

Reference numeral 22 denotes a screw shaft. Screw shaft 22
Is in the middle of the two sets of toggle links 13 and 16,
The upper end and the lower end are supported by the bearing 23 of the fixed plate 2 and the bearing 24 of the holding member 1 ′ fixed to the guide rod 25 vertically fixed to the fixed plate 2, so that the movement in the axial direction is stopped. It is provided vertically to be rotatable in the direction. A nut member 21 is screwed to the screw shaft 22 to form a screw mechanism 31. The bearing 23 is fitted in a bearing housing 34 fitted in the through-hole 2 a of the fixed board 2. The flange 34a of the bearing housing 34 is fixed to the fixed platen 2 with a plurality of bolts (not shown), and the bolts can be loosened and pulled out from the through holes 2a of the fixed platen 2.
The inner diameter of the through hole 2 a is larger than the outer diameter of the nut member 21 so that the nut member 21 can pass therethrough. The nut member 21 is detachably connected to the crosshead 20 by bolts (not shown). Screw mechanism 3
1 preferably has a ball screw structure or a roller screw structure.

The crosshead 20 is guided by a plurality of guide rods 25 (only one is shown in FIG. 1) which is vertically fixed to the fixed board 2 or the machine body 1.
Therefore, when the screw shaft 22 is rotated, the nut member 21 is rotated.
Thereby, the crosshead 20 is moved up and down along the guide rod 25.

A driven pulley 26 is detachably attached to the lower end of the screw shaft 22, and is provided with a drive motor 2 such as a servo motor.
7 is connected to a drive pulley 28 by a timing belt 29. The pulleys 26 and 28 and the belt 29 are
The transmission mechanism 30 that transmits the rotation of the screw 7 to the screw shaft 22 is configured, but the transmission mechanism 30 may use another transmission member such as a gear. The drive motor 27 is fixed to the machine body 1 and has a brake 27a. The brake 27a operates when the power is turned off, and the drive motor 27
It is configured to apply braking to the free rotation of the vehicle.

The mounting positions of the pulley 26 and the drive motor 27 are not limited to those shown in FIG.
Can be attached to the upper portion of the screw shaft 22 as in the second embodiment shown in FIG. 2, and the drive motor 27 can be fixed near the fixed platen 2 or to the fixed plate 2 itself. The outer diameter of the pulley 26 shown in FIG.
However, in the case of the pulley 26 having an outer diameter larger than the inner diameter of the through hole 2a, the present invention can be implemented by being configured to be splittable.

Although only one tie bar 4 is shown in FIG. 1, two or more tie bars 4 are used (normally four tie bars 4 and three in the case of a rotary type).
Book) is provided. The lower end of the tie bar 4 is screwed into the adjustment nut 32, and by rotating the adjustment nut 32, the distance between the movable platen 3 and the end plate 5 can be finely adjusted according to the thickness of the molds 7 and 8. I can do it.

In the case of a normal vertical injection molding machine, the fixed platen 2
The mold 7 is mounted on the rotary table 35 in a rotary vertical injection molding machine having a rotary table 35. In this case, a removal hole 35 a that allows the bearing housing 34 to be pulled out is formed in the rotary table 35. A lid 36 is detachably fitted into the extraction hole 35a.

Next, the operation of the above-configured mold clamping device of the vertical injection molding machine according to the present invention will be described. When the power of the drive motor 27 is turned on from the mold opening state on the left side of FIG. 1, the brake 2 which has stopped the free rotation of the drive motor 27 until then.
7a is turned off, the drive motor 27 is operated and the screw shaft 2
2, the nut member 21 is lowered together with the crosshead 20, so that the inner end of the toggle link 16 is pushed down by the toggle piece 18, and as a result, the toggle link 16, 13 The end plate 5 is lowered by pivoting inward about the pivots 14 and 12 so as to approach the screw shaft 22. As a result, the movable platen 3 moves downward with the mold clamping together with the end plate 5, and when the toggle links 13 and 16 extend linearly as shown in the right side of FIG. 1, the drive motor 27 is stopped to complete the mold clamping. In this case, the brake 27a operates and the drive motor 2
7 free rotation. The operation of the second embodiment shown in FIG. 2 is the same as that of FIG.

In the mold clamping state on the right side of FIG. 1, the power is turned on, the drive motor 27 is operated (the brake 27a is turned off), and the screw shaft 22 is rotated in the reverse direction. Then, the movable platen 3 opens upward and moves.
When the power is turned off and the driving of the drive motor 27 is stopped to complete the mold opening, the brake 27a is actuated immediately and the drive motor 2
Stop the free rotation of 7.

When it becomes necessary to replace the screw mechanism 31, the nut member 21 is separated from the crosshead 20, the pulley 26 is removed from the screw shaft 22, and the flange 34a is fixed to the fixed platen 2. The bearing housing 34 is pulled out from the through hole 2a by applying upward force to the screw mechanism 31 and the bearing housing 34, and the lower end of the screw shaft 22 is fixed to the bearing 2 by applying upward force to the screw mechanism 31 and the bearing housing 34.
4, the nut member 21 is pulled up on the fixed platen 2 and removed while the nut member 21 is screwed to the screw shaft 22.

In the case of a rotary vertical injection molding machine, the lid 3
Needless to say, the screw mechanism 31 is removed in a state where the removal hole 6 is removed and the extraction hole 35a is aligned with the through hole 2a. Assembling of the screw mechanism 31 is performed in the reverse of the above.

In the above-mentioned toggle-type mold clamping device, when the movable platen 3 is opened and closed by the operation of the toggle mechanism 11, there is no need to move the transmission mechanism 30 or the drive motor 27, so that the structure is simplified. . Therefore, it is possible to manufacture a highly reliable mold clamping device which is less likely to break down and is inexpensive. In addition, since there is almost no structural restriction on the rotation angle of the toggle link 16, it can be increased to increase the opening / closing stroke of the movable platen 3. Also, brake 2
7a is configured to operate when the power is turned off to apply a brake to the free rotation of the drive motor 27, so that it operates automatically even in the event of an unexpected power outage, preventing the movable platen 3 from lowering naturally. Is done. Moreover, since the brake 27a does not consume power during braking, power consumption can be reduced.

Further, the screw mechanism 31 can be lifted up on the fixed platen 2 and removed, so that it is not necessary to disassemble the toggle mechanism 11 or remove the fixed platen 2 or the rotary table 35 when removing the screw mechanism 31. In addition, the replacement work of the screw mechanism 31 is facilitated.

FIG. 3 shows a third embodiment of the present invention.
In the case of this mold clamping device, the toggle piece 18 is connected to the connecting pin 1.
The toggle links 13 and 16 which are connected to the intermediate portion of the toggle link 13 at 9 and which are bent inward by bringing the toggle pin 15 close to the screw shaft 22, connect the toggle pin 15 to the screw shaft 2.
2 so as to be separated from the second and extend linearly. The pivot 14 of the end plate 5 is provided at a position directly below the pivot 12 of the fixed platen 2 or at a position slightly inward from the position directly below. Other structures and operations are the same as those of the mold clamping device of FIG.

FIG. 4 shows a fourth embodiment of the present invention.
In the case of this mold clamping device, the crosshead 20 is disposed below the end plate 5, and the end plate 5 is formed with a through hole 5a through which the nut member 21 can pass. In this embodiment, when replacing the screw mechanism 31, the nut member 21 passes through the through hole 5a. Other structures and operations are the same as those of the apparatus of FIG. 1, but the height can be reduced in this mold clamping apparatus.

Each of the mold clamping devices shown in FIGS.
Although the crosshead 20 is configured to descend and clamp the mold, the crosshead 20 may be elevated and clamped. Further, the injection molding machine shown in FIGS. 2 to 4 can be of a rotary type. Toggle link 1
Either one or both of 3 and 16 may be configured such that two or more link units are pin-connected.

[0032]

As described above, according to the first aspect of the present invention, the movable plate is fixedly provided on the upper end of the tie bar above the fixed plate fixed to the machine body, and the movable platen is provided below the fixed plate. In a vertical injection molding machine in which an end plate is fixed to the lower end of the tie bar and vertically movable with respect to the fixed plate together with the movable plate, a screw shaft is provided below the fixed plate. The upper end is supported by a bearing of a bearing housing which is removably fitted to the through hole of the fixed plate, and the lower end is provided by being supported by a bearing of the machine body or the fixed plate. An outer diameter is made smaller than the inner diameter of the through hole, and a nut member for vertically moving the end plate together with the movable plate by vertical movement along the screw axis is screwed. Rotate the nut Member being a drive motor that moves is contacted configured vertically, it is not necessary to the drive motor and the transmission mechanism and the movable structure, the structure is simplified.
Therefore, it is possible to manufacture a highly reliable mold clamping device which is less likely to break down and is inexpensive. Further, since the screw mechanism can be pulled out onto the fixed platen, the labor required for replacing the screw mechanism can be greatly reduced.

The toggle link, which is connected to the fixed plate and the end plate by a toggle pin so as to be able to bend up and down freely by a toggle pin, is extended and moved by the vertical movement of a crosshead connected to the toggle link by a toggle piece. If a toggle mechanism is provided to move the panel to the mold, there is almost no restriction on the rotation angle of the toggle link in terms of structure.Therefore, the rotation angle of the toggle link is increased to increase the opening and closing stroke of the movable plate. The workability of the mold clamping device can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a mold clamping device of a vertical injection molding machine according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

FIG. 4 is a sectional view showing a fourth embodiment of the present invention.

FIG. 5 is a front view of a mold clamping device of a conventional electric vertical injection molding machine.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 machine body 1 ′ holding member 2 fixed plate 2 a through hole 3 movable plate 4 tie bar 5 end plate 5 a through hole 11 toggle mechanism 12, 14 pivot 13, 16 toggle link 15 toggle pin 18 toggle piece 19 connecting pin 20 crosshead 21 nut member 22 Screw shaft 27 Drive motor 30 Transmission mechanism 31 Screw mechanism 34 Bearing housing 35 Rotary table 35a Extraction hole

Claims (9)

[Claims] A movable plate fixed to an upper end of a tie bar provided above a fixed plate fixed to a machine body; and an end plate fixed to a lower end of the tie bar below the fixed plate. In a vertical injection molding machine provided vertically with respect to the fixed plate together with a movable plate, a screw shaft is fitted below the fixed plate so as to be able to be pulled out into a through hole of the fixed plate. The upper end is supported by the bearing of the bearing housing, and the lower end is supported by the bearing of the machine body or the fixed plate. The screw shaft has an outer diameter smaller than the inner diameter of the through hole, and A nut member for vertically moving the end plate together with the movable plate by vertical movement along the screw shaft is screwed, and a drive motor for rotating the screw shaft to vertically move the nut member is mounted on the screw shaft. Contacted A mold clamping device for a vertical injection molding machine, characterized in that: 2. A mold clamping device for a vertical injection molding machine according to claim 1, wherein a removal hole of a bearing housing is formed in a rotary table rotatably provided on a fixed platen. 3. A toggle link, which is connected between a fixed plate and an end plate by a toggle pin so as to be able to bend up and down freely by a toggle pin, is extended by a vertical movement of a crosshead connected to the toggle link by a toggle piece. 2. A toggle mechanism for clamping and moving the movable platen by means of a nut member screwed to a screw shaft above the end plate, wherein the crosshead is detachably connected to the nut member.
Or a mold clamping device for a vertical injection molding machine according to 2. 4. A toggle link, which is connected between a fixed plate and an end plate by a toggle pin so as to be able to bend and extend up and down by a toggle pin, is extended by a vertical movement of a crosshead connected to the toggle link by a toggle piece. A toggle mechanism for clamping and moving the movable platen is provided by detachably connecting the crosshead to a nut member screwed to a screw shaft below the end plate, and the nut member is allowed to pass through the end plate. 3. The mold clamping device for a vertical injection molding machine according to claim 1, wherein a through hole is formed. 5. The mold clamping device for a vertical injection molding machine according to claim 3, wherein the toggle link is configured to extend by moving the toggle pin closer to the screw shaft. 6. The mold clamping device for a vertical injection molding machine according to claim 3, wherein the toggle link is configured to extend by moving the toggle pin away from the screw shaft. 7. The toggle piece according to claim 3, wherein the toggle piece is connected to the end plate by a connecting pin at a free end opposite to the toggle pin of the toggle link pivotally connected to the end plate. Clamping device for vertical injection molding machine. 8. The vertical injection device according to claim 3, wherein the toggle piece is connected by a connecting pin to an intermediate portion of a toggle link that is pivotally connected to the fixed plate by a pivot. Mold clamping device for molding machines. 9. The mold clamping device for a vertical injection molding machine according to claim 1, wherein the screw mechanism has a ball screw structure or a roller screw structure.