JP3249666B2 - Mold clamping device of molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a mold clamping device of a molding machine such as an injection molding machine or a foam molding machine.

[0002]

2. Description of the Related Art Generally, mold clamping and opening of a molding machine must be performed quickly and reliably in order to shorten a working cycle and stabilize a molded product. FIG. 9 shows one cycle in the foam molding operation. According to the figure, in the molding operation, high-speed mold closing, cracking stop, material filling, re-mold closing,
Intensification mold clamping, heating, cooling, mold opening, product ejection, and re-mold opening are sequentially performed. In the heating / cooling step, the pressure-intensifying cylinder is operated to clamp the mold at high pressure so that the mold is not opened by the expansion pressure of the raw resin. on the other hand,
When the high-speed mold is closed or the high-speed mold is opened, the ball screw is operated to quickly move the fixed mold, and the mold opening and closing one cycle operation is quickly performed.

Next, a conventional example will be described. The first conventional example (not shown) is a method in which a mold is opened by a ball screw and a servomotor to perform mold clamping and pressure-increasing mold clamping. In this case, direct clamping and pressure-increasing mold clamping are performed by a ball screw. It is necessary to increase the strength of the ball screw, and as a result, the diameter of the ball screw increases, the servo motor also has a large capacity, and the cost of electric equipment and power consumption increases.

A second conventional example (not shown) uses a ball screw, a small capacity servomotor and a speed reducer. When the mold is opened / closed, the speed reducer is not operated, and the rotation of the small capacity servomotor is controlled. When the high-speed mold is opened / closed by direct transmission to the ball screw, and the pressure-increasing mold is tightened, the reduction gear is operated by switching with an electromagnetic clutch or air clutch to reduce the high-speed rotation of the small-capacity servo motor and at the same time reduce the gear. And the ball screw is rotated under pressure increase by the speed reducer. In this case as well, the diameter of the ball screw needs to be increased not only to be able to withstand the pressure increase by the speed reducer, but also requires a speed reducer and an electromagnetic clutch, thus increasing the equipment cost.

A third conventional example (not shown) is a method of performing mold opening / closing and pressure-increasing mold clamping with a hydraulic cylinder. Hydraulic cylinders can easily obtain high pressure compared to ball screws.On the other hand, hot water temperature control or cracking cylinders are required to perform highly accurate stop operations. In the case of hydraulic pressure, a low-pressure mold closing device is required at the time of mold closing, and there is a problem that the hydraulic circuit becomes complicated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional disadvantages, and an object of the present invention is to combine a ball screw with a hydraulic cylinder and an intensifying cylinder to form a small-diameter ball screw. With a small capacity servo motor, high-speed mold opening and closing is performed, and a hydraulic cylinder is used to perform pressure-increasing mold clamping work. It is intended to provide.

[0007]

According to a first aspect of the present invention, there is provided a mold clamping apparatus for a molding machine, comprising: a movable plate on which a movable mold 1 is mounted.
2. Fixing in which the fixed mold 3 is mounted facing the moving mold 1
The fixed mold 3 of the plate 4 and the fixed plate 4 is mounted.
Cylinder 5, cylinder 5 provided on the surface opposite to the surface
Provided on the fixed plate 4 and the piston 6 sliding inside
One end is fixed to the moving plate 2 through the through hole.
And the other end is fixed to the piston 6 to move the moving plate 2
Hollow cylinder lock that guides against the fixed plate 4
7, the nut 8 fixed to the piston 6, and the nut 8
A screw that is removably screwed and disposed in the cylinder rod 7
And a rotating device 10 for rotating the screw rod 9, and a screw rod 9.
Pressing the piston 6 by applying hydraulic pressure to the cylinder 5
Pressurizing device 1 for bringing moving mold 1 into close contact with stationary mold 3
2 is a mold clamping device for a molding machine.

According to this, the high-speed opening and closing operation is performed by the screw rod 9.
Is rotated to operate the piston 6 so that the movable plate 2 having the movable mold 1 performs a high-speed mold opening / closing operation on the fixed mold 4. On the other hand, in the pressure increasing mold clamping step, the pressure increasing device 12 is operated to supply the pressure oil to the cylinder 5 to clamp the moving mold 1 to the fixed mold 3. Thereby, quick mold opening and closing and high-pressure mold clamping can be achieved.

[0009]

In the high-speed opening / closing operation, the rotating device 10 is operated to rotate the screw rod 9, and the nut 8 and the piston 6 to which the nut 8 is fixed are moved forward and backward relative to the cylinder 5. Thus, the movable plate 2 slidably mounted on the cylinder rod 7 and having the movable mold 1 performs a high-speed mold opening / closing operation on the fixed mold 3. On the other hand, in the pressurizing mold clamping process, the
Is supplied to the pressure-increasing-side pressure oil chamber 11a to move the piston 6 away from the fixed plate 4 (that is, the direction in which the movable mold 1 moves closer to the fixed mold 3), and Then, the moving mold 1 is clamped by the pressure increasing mold. At this time, the increased pressure is applied only to the cylinder rod 7 as tension, and no force is applied to the screw rod 9. Therefore, the screw rod 9 needs to have sufficient strength to move the moving plate 2 on which the moving mold 1 is mounted at a high speed, and may have a small diameter. In the case of the drawing, the cylinder rod 7 is hollow, and the screw rod 9 is inserted therein. However, the present invention is not limited to this, and both may be arranged in parallel.

[0011] The mold clamping device of the molding machine according to claim 2 is a transfer device.
A moving plate 2 on which a moving mold 1 is mounted, and a pair with the moving mold 1
The fixed plate 4 on which the fixed mold 3 is mounted
On the surface opposite to the surface on which the fixed mold 3 of rate 4 is mounted
Cylinder 5 with one end fixed, slides inside cylinder 5
Piston 6 and a through hole provided in the fixed plate 4
And one end is fixed to the moving plate 2 while the other end is
Is fixed to the piston 6 and the moving plate 2 is fixedly played.
Hollow cylinder rod 7 that guides
A nut 8 rotatably mounted on the other end of the
The end is fixed to the piston 6 and screwed to the nut 8 so that it can advance and retreat.
, A rotating device 10 for rotating the screw rod 9 and the nut 8,
And pressurize piston 6 by applying hydraulic pressure to cylinder 5
To make the movable mold 1 adhere to the fixed mold 3
This is a mold clamping device for a molding machine, which includes a pressure device 12.

The mold clamping device according to claim 2 has a slightly different structure from the mold clamping device according to claim 1 , but has the same operating principle. That is, in the high-speed opening and closing operation, the rotating device 10 is operated to rotate the nut 8. Then, the piston 6 moves forward and backward relative to the cylinder 5 to which the nut 8 is fixed. Thereby, the movable plate 2 slidably supported by the cylinder rod 7 and having the movable mold 1
Performs a high-speed mold opening and closing operation on the fixed mold 3.
On the other hand, in the pressure-intensifying mold clamping step, the pressure-intensifying cylinder 12 is operated to supply hydraulic pressure to the pressure-intensifying-side hydraulic oil chamber 11a of the cylinder 5 so that the piston 6 is separated from the fixed plate 4 (that is, the movable mold 1 is fixed). (In a direction approaching the mold 3), and the movable mold 1 is clamped to the fixed mold 3 by a pressure-increasing mold. At this time, the increased pressure is applied only to the cylinder rod 7 as tension, and no force is applied to the screw rod 9. Therefore, the screw rod 9 needs to have sufficient strength to move the moving plate 2 on which the moving mold 1 is mounted at a high speed, and may have a small diameter.

[0013] molding machine mold clamping device according to claim 3, solid
Fixed plate 4 on which fixed mold 3 is mounted, fixed plate 4
Cylinder plate 1 arranged at a predetermined distance from
5. Arranged between the fixed plate 4 and the cylinder plate 15.
The movable mold 1 is placed on the surface facing the fixed plate 4.
The moving plate 2 to be mounted, provided on the moving plate 2
Fixed plate 4 and cylinder play
Tie bar 14 and cylinder press
Cylinder 5 fixed to sheet 15, slides in cylinder 5
Rotatably mounted on the piston 6 and the cylinder plate 15
The nut 8 is screwed into the nut 8 so that it can move forward and backward.
One end is fixed to the moving plate 2 and the other end is a piston
A rotating device for rotating a screw rod 9 and a nut 8 fixed to 6
Piston 10 by applying hydraulic pressure to the
The movable mold 1 is brought into close contact with the fixed mold 3 by pressing
A mold clamping device for a molding machine, comprising
You.

Although the structure of the mold clamping device of the third aspect is different from that of the mold clamping devices of the first and second aspects, the operation principle is similar. That is, in the high-speed opening and closing operation, the rotating device 10 is operated to rotate the nut 8. Then, the screw rod 9 screwed into the nut 8 moves forward and backward together with the piston 6. As a result, the moving plate 2 mounted on the tip of the screw rod 9 also moves forward and backward at a high speed, and is opened and closed at a high speed. On the other hand, in the pressure-intensifying mold clamping step, the pressure-intensifying device 12 is operated to supply hydraulic pressure to the pressure-intensifying-side pressure oil chamber 11 b of the cylinder 5 and the piston 6
And the movable mold 1 is clamped to the fixed mold 3 by the pressure increasing mold.

The common point of the mold clamping device according to the present invention is that when the pressure is increased, the rotating device 10 is kept free and freely rotates with respect to the advance of the screw rod 9. .
Further, during the high-speed opening / closing operation, the pressure increasing device 12 is free, and the pressure oil in the pressure increasing pressure oil chamber 11b can freely move between the pressure increasing device 12 and the pressure increasing device 12. In addition, since the high-speed opening / closing operation is performed with the screw rod 9, the cracking stop position accuracy is high,
Also, since the pressure intensifying mold clamping is not performed by the rotating device 10, the rotating device
There is a point that 10 is enough with small capacity.

In addition, in the first and second aspects, the pressure-intensifying mold is clamped through the cylinder rod 7 and no pressure-increasing force is applied to the screw rod 9. whereas sufficient movement plate 2 mounted with only the thickness withstand high speed type opening and closing operation of the case of claim 4, since increasing pressure is applied to the threaded rod 9, it requests the strength to withstand increased pressure Is different.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a molding machine according to the present invention. The molding machine includes all devices that use a fixed mold and a movable mold, such as a foam molding machine and an injection molding machine. Here, a foam molding machine will be described as an example. 1 and 3 show a first embodiment of the present invention, FIGS. 4 and 5 show a second embodiment, and FIGS. 6 and 7 show a third embodiment.
This is an example. A first embodiment of the present invention will be described in detail with reference to FIGS. It is to be noted that components having the same function are denoted by the same reference numerals throughout the drawings.

FIGS. 1 and 3 show a first embodiment of a mold clamping device according to the present invention.
It will be described according to. 1 is a moving mold, 2 is a moving plate,
Reference numeral 3 denotes a fixed mold, 4 denotes a fixed plate, and the fixed mold 3 is fixed to the inner surface side of the fixed plate 4 as described above. 2 is fixed to the inner surface. The fixing plate 4 is a stand
13 and movable mold 1 with respect to fixed mold 3.
Are separated from each other. Reference numeral 5 denotes a cylinder, which is mounted on the fixed plate 4 on the opposite side of the fixed mold 3. Reference numeral 6 denotes a piston reciprocally mounted in the cylinder 5. Reference numeral 7 denotes a cylinder rod, one end of which is mounted on the moving plate 2, and the other end of which is mounted on the piston 6, which is inserted into a through hole 18 of a mounting portion 17 of the fixed plate 4.

Numeral 8 is a nut mounted on the piston 6. The nut 8 may be a normal spiral screw recessed on the inner surface, but in the present embodiment, a ball nut is used for smoother rotation. Reference numeral 9 denotes a screw rod which is screwed into the nut 8 so as to be able to advance and retreat. In this embodiment, a ball screw is used. One end of the screw rod 9 is rotatably held by a head cover 19 via a bearing, and the other end is housed in an insertion hole 20 formed in the cylinder rod 7. 21 is a rod cover, and a fixing plate 4
Is fixed to the mounting portion 17. Reference numeral 11a denotes a pressure-intensifying-side pressure oil chamber formed between the rod cover 21 and the piston 6, and communicates with a pressure oil inlet 23 formed in the rod cover 21. 22 is a rod side bush.

Reference numeral 10 denotes a rotating device, which includes a timing pulley 10a,
It comprises a drive pulley 10b, a servomotor 10c and a timing belt 10d. FIG. 2 is a front view of the rotating device 10, in which a timing pulley 10a is mounted on one end of the screw rod 9, and a drive pulley 10b is mounted on a drive shaft of a servomotor 10c. The timing belt 10c is suspended between the timing pulley 10a and the driving pulley 10b, and the driving force of the servo motor 10c is
0a.

Reference numeral 12 denotes a pressure booster, which comprises a cylinder body 12a, a pressure booster piston 12b, a pressure booster rod 12c, a small-diameter cylinder portion 12d, and a pressure oil reservoir 12e. The pressure booster piston 12b reciprocates in the cylinder body 12a. Slide freely, booster rod 1
2c reciprocates in the small-diameter cylinder portion 12d together with the pressure-increasing piston 12b. The pressurized oil reservoir 12e is filled with pressurized oil, and its open end is open to the base of the small-diameter cylinder portion 12d. The distal end of the small-diameter cylinder portion 12d is connected to a pressure oil inlet 23 via a hydraulic line, and the pressure oil is supplied to the pressure-increase side pressure oil chamber 11
Supply inside a.

Reference numeral 24 denotes a hydraulic pressure switching valve which is connected to both ends of the cylinder body 12a, and serves to reciprocate the pressure-intensifying piston 12b. FIG. 3 is a partially detailed drawing of FIG. Reference numeral 25 denotes an eject mechanism, which includes the following members. Reference numeral 36 denotes a fixed eject plate, which is disposed on the back of the fixed plate 4. An eject guide 28 is provided between the fixed eject plate 36 and the fixed plate 4, and the fixed eject plate 36 is fixed by the eject guide 28. Are fixed to the fixing plate 4.

An eject operation plate 30 is supported by the eject guide 28 so as to be reciprocable. Reference numeral 26 denotes an eject nut, which is mounted on an eject operation plate 30 and into which an eject screw 27 is screwed. One end of the eject screw 27 is rotatably held by the fixed plate 4, and the other end is rotatably held by the fixed eject plate 36. Further, a timing pulley 34 is mounted on the other end projecting portion of the eject screw 27, and is rotated by an eject timing belt 35.

Reference numeral 29 denotes an eject operation rod mounted on the eject operation plate 30, and a back hole 2a formed in the fixed plate 4.
And is inserted into the steam chamber 37 inside the fixed plate 4. 31 is an eject plate, and an eject operation rod 29
It is attached to the tip. Numeral 32 denotes an eject pin, which projects through the eject hole 3a formed in the fixed mold 3 to the cavity surface side of the eject hole 3a. A return spring 33 urges and pushes the eject pin 32 back into the steam chamber 37 formed by the fixed mold 3 and the fixed plate 4. Reference numeral 38 denotes a molded product, which is fitted into the cavity surface of the fixed mold 3.

Next, the operation of the first embodiment will be described.
FIG. 1 is a view showing a mold opening state. First, a case where the high-speed mold closing is performed from this state to the cracking position will be described. By driving the servo motor 10c, the screw rod 9 is rotated at a high speed via the timing pulley 10a. Screw rod 9
Since the nut 8 screwed with the nut 8 is mounted and fixed on the piston 6 of the cylinder rod 7, the nut 8 is
Inside, screwed and moves to the right. A head cover 19 is rotatably mounted on the tip of the screw rod 9 via a bearing, and the cylinder rod 7, the moving plate 2 and the moving mold 1 move at high speed in the direction of the fixed mold 3 together with the nut 8. At this time, the pressure-increase side pressure oil chamber 11a expands, so that the hydraulic pressure switching valve 24 is at the position (a) as shown in the figure, and the pressure-increase piston 12b is pulled back to open the outlet of the pressure oil reservoir 12e, and the pressure oil Is drawn into the pressure-increasing pressure oil chamber 11a more freely than the pressure oil reservoir 12e.

As shown in FIG. 9, the rotating speed of the rotating device 10 is accelerated to a certain speed at the time of the rise of the high-speed mold closing, and is maintained at the same speed after reaching the certain speed. When the movable mold 1 approaches the fixed mold 3 at a predetermined cracking position, it is gradually decelerated, is held at a low speed for a certain time immediately before the fixed mold 3, and then is decelerated again to stop at the predetermined cracking position. . (Stopping cracking) During this period, high-speed trapezoidal feedback driving using the screw rod 9 and the nut 8 is exclusively performed. In the foam molding, a slight gap is provided between the movable mold 1 and the fixed mold 3 at this time. Subsequently, a filler (not shown) is operated to fill the raw material beads into the cavity formed by the movable mold 1 and the fixed mold 3. When the filling of the raw material is completed, the servomotor 10c is operated again to re-close the mold until the movable mold 1 comes into contact with the fixed mold 3.

The position where the movable mold 1 contacts the fixed mold 3 is detected, and the process is switched to the pressure increasing step. In the pressure increasing step, the hydraulic pressure switching valve 24 is operated to switch from the position (a) to the position (b), the pressure increasing piston 12b is advanced, and the pressure increasing rod 12c is advanced into the small diameter cylinder portion 12d. When the tip of the pressure-intensifying rod 12c closes the opening of the pressure-oil reservoir 12e, the small-diameter cylinder portion 12d, the pressure-oil pipeline and the pressure-increase-side pressure-oil chamber 11a form a closed circuit, and the pressure oil in the small-diameter cylinder portion 12d is Pressure oil chamber 1
1a, the piston 6 is separated from the fixed plate 4, and the movable mold 1 is further pressed against the fixed mold 3 (right in the figure). (Intensification mold clamping)

After the pressure-increasing mold has been clamped in this way, high-temperature steam is supplied to the steam chamber 37 of the fixed mold 3 (or the movable mold 1) to form the movable mold 1 and the fixed mold 3. Through the cavity, and into the steam chamber 37 of the movable mold 1 (or the fixed mold 3). As a result, the raw material beads filled in the cavity are heated and expanded to fill the cavity. Thereafter, cooling water is passed through the movable mold 1 and the fixed mold 3 to cool the molded product. When the cooling of the molded product is completed, the hydraulic switching valve 24 is operated in the reverse direction to move it from the position (b).
(a) The position is switched to the position, the pressure-intensifying piston 12b is retracted, and the pressure oil reservoir 12e is opened.

Next, the servo motor 10c is rotated in the reverse direction, and the moving plate 2 is moved to the left side in the drawing by operating in the opposite direction to that described above, and the moving mold 1 is separated from the fixed mold 3 to open the high-speed mold. I do. At this time, the piston 6 moves to the left in the figure, and the pressure-increasing-side pressure oil chamber 11a is reduced. Fixed mold side pressure oil 11a
As the pressure decreases, the pressure oil in the pressure-intensifying-side pressure oil chamber 11a returns to the pressure oil reservoir 12e through the pipeline. At this time, the hydraulic switching valve 24
Has already been switched to the position (a) as described above, and the pressure-intensifying piston 12b is in a direction to be pulled back (leftward in the figure), the pressure oil reservoir 12e is open, and the return of the pressure oil has no resistance. Is being done.

After the high-speed mold opening is performed as described above, the mold opening speed is temporarily reduced, and during this time, the eject mechanism 25 is operated to perform product protrusion, and the molded product 38 is taken out from the mold 3 (or 1). After that, the high-speed mold opening is performed again. When the mold re-opening is completed, the servo motor 10c is stopped. Then, the process proceeds to the next foam molding. The above is a series of operations according to the first embodiment of the present invention. It has been described that the closing of the mold after the stopping of the cracking is performed by the servomotor 10c. However, the present invention is not limited to this. Needless to say, it may be closed. Further, the switching of the pressure intensifier 12 has been described to be performed by the hydraulic pressure switching valve 24, but is not limited to this.
It is also possible to use a motor and screw mechanism as described later.

Next, a second embodiment of the present invention will be described with reference to FIGS. The description of the same points as in the first embodiment will be omitted. In the second embodiment, the screw rod 9 projects in the direction opposite to that of the first embodiment, and is screwed into the nut 8 rotatably held by the head cover 19. The timing pulley 10a is integrally fixed to the nut 8, and is connected to the drive pulley 10b via a timing belt 10d. In FIG. 5, reference numeral 39 denotes a connecting member for connecting the screw rod 9 and the piston 6 to each other. The operation of the second embodiment is similar to that of the first embodiment.

Next, a third embodiment of the present invention will be described with reference to FIGS. Also in this case, the same parts as described above will not be described. The structure of the third embodiment is slightly different from that of the first and second embodiments. The fixed plate 4 is provided upright at one end of the gantry 13 and the cylinder plate 15 is provided upright at the other end of the gantry 13. . A tie bar 14 is provided between the fixed plate 4 and the cylinder plate 15, and the movable plate 2 is slidably held by the tie bar 14. The cylinder 5 is fixed to the back surface of the cylinder plate 15 via a fixed-side rod cover 21a, and a pressure oil inlet 23 provided in the head cover 19 and the small diameter cylinder portion 12d are connected by a pressure oil pipe.

Reference numeral 16 denotes a rotation holding unit, which is constituted by a sleeve 16a, a bearing 16b, and a housing 16c.
The nut 8, the timing pulley 10a, and the sleeve 16a are integrally formed by bolts, and are rotated by a timing belt 10d. Sleeve 1
6a is rotatably held by a housing 16c via a bearing 16b. One end of the screw rod 9 is attached to the piston 6, the other end is attached to the moving plate 2,
The rotation of the moving plate 2 moves forward and backward.

The operation of the third embodiment will be described with reference to FIGS. As described above, by switching the hydraulic pressure switching valve 24 to the position (a), the pressure-intensifying piston 12b is moved to the left in the drawing to open the inlet of the hydraulic pressure reservoir 12e, and the pressure oil is supplied to the pressure-increasing-side pressure oil chamber 11b of the cylinder 5. Be supplied freely. Subsequently, the servo motor 10c is operated to rotate the timing pulley 10a via the timing belt 10d. As a result, the nut 8 integrally formed with the timing pulley 10a rotates, and the screw rod 9 is moved to the left in the figure (the fixed mold 3).
Side) to bring the movable mold 1 close to the fixed mold 3. At this time, the pressure oil in the pressure oil reservoir 12e is automatically sucked into the pressure-intensifying-side pressure oil chamber 11a through the pipeline. Hereinafter, stop the cracking position, fill the raw material, reclose the mold, pressurize the mold,
Cooling process, high-speed mold opening, product ejection, re-mold opening, etc. are the first.
This is the same as the embodiment. Also in this case, when the pressure-intensifying piston 12b is operated to advance the piston 6 in the pressure-intensifying mold clamping, the nut 8 screwed to the screw rod 9 rotates, so that the servomotor 10c is turned off. As a result, the servomotor 10c rotates without load, and the pressure-increasing mold clamping by hydraulic pressure is performed.

FIG. 9 is a flowchart according to the present invention. The screw rod 9 (ball screw) is used for both high-speed closing and re-closing after cracking is stopped, and the mold is opened. It may be used by tightening, or the screw rod (9) (ball screw) is used for high-speed mold closing and mold opening, and the pressure-intensifying cylinder 12 is used for both mold re-closing after cracking stops and pressure-increasing mold clamping. You may make it.

In addition, as shown in FIG. 8, a screw mechanism is adopted as the pressure intensifier 12 instead of the pressure intensifier piston 12b, and the pressure intensifier rod 12c is reciprocated by the pressure intensifier screw 12g via the pressure intensifier nut 12f. You may make it slide. The pressure-increasing nut 12f is driven to rotate forward and reverse by a pressure-increasing motor 12h via a pressure-increasing belt 12i.

[0037]

According to the first and second aspects of the present invention, the movable plate on which the movable mold is mounted can be opened and closed at a high speed with respect to the fixed mold by rotating the screw rod or the nut.
In the pressure-increasing mold clamping step, pressure-increasing pressure is applied only to the cylinder rod as tension, and no pressure is applied to the threaded rod so that the pressure-increasing cylinder can perform pressure-increasing mold clamping. Therefore, there is an advantage that the screw rod needs only a strength enough to move the moving plate on which the moving mold is mounted at a high speed, and may have a small diameter. Others
Since the high-speed opening and closing operation is performed only with a screw rod or nut, the accuracy of switching from the high-speed opening and closing operation to the accurate stop at the cracking stop position and the switching position accuracy from the re-mold closing to the pressure increasing mold clamping operation are dramatically improved. There are advantages too. Also, a servo motor can be used as a rotating device,
The pressure can be adjusted freely, and the control benefits are great.

The third aspect of the present invention is structurally different from the first and second aspects. Also in this case, the high-speed opening and closing operation is performed by rotating the nut and advancing and retreating the screw rod screwed to the nut. The point that the switching accuracy from the mold closing to the pressure increasing mold clamping operation is dramatically improved, and the servomotor can be used as a rotating device, the speed and pressure can be freely adjusted, and there are great control advantages. It is. In this case, the screw rod also serves as a piston rod, and in the pressure-increasing mold clamping step, the increased pressure is applied to the screw rod as a force in the compression direction. Therefore, unlike the first and second aspects, the screw rod basically needs to be thick enough to withstand the increased pressure, but even in this case, the rotating device is kept free, The pressure increase is not directly applied to the nut, but is applied only to the threaded rod, so that a threaded rod having a smaller diameter than in the conventional example is sufficient.

[Brief description of the drawings]

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

FIG. 2 is a front view of the rotating device of the present invention.

FIG. 3 is an enlarged view of a main part of FIG. 1;

FIG. 4 is a plan view of a second embodiment of the present invention.

FIG. 5 is an enlarged view of a main part of FIG. 4;

FIG. 6 is a front view of a third embodiment of the present invention.

FIG. 7 is an enlarged view of a main part of FIG. 6;

FIG. 8 is a sectional view of another embodiment of the pressure booster used in the present invention.

FIG. 9 is a time chart of a general mold opening / closing process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Moving mold 2 ... Moving plate 3 ... Fixed mold 4 ... Fixed plate 5 ... Cylinder 6 ... Piston 7 ... Cylinder rod 8 ... Nut 9 ... Screw rod 10 ... Rotating device 11a ... Pressure increasing pressure oil chamber 12 ... Pressure increasing apparatus

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-345339 (JP, A) JP-A 62-48519 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 33/22 B22D 17/26 B29C 45/68

Claims (3)

(57) [Claims] 1. A movable plate on which a movable mold is mounted, and a fixed press on which a fixed mold is mounted opposite to the movable mold.
And the surface of the fixing plate opposite to the surface on which the fixed mold is mounted.
A cylinder provided on the opposite surface, a piston sliding in the cylinder, and a through hole provided in the fixed plate,
One end is fixed to the moving plate, and the other end is
The moving plate is fixed to the fixed plate.
Hollow cylinder rod, the piston secured to a nut, the cylinder rod is screwed to freely advance and retreat in the nut to guide against
Screw rod disposed in the inside, a rotation device for rotating the screw rod, and the cylinder
By applying hydraulic pressure inside and pressing the piston
A pressure intensifier for bringing the movable mold into close contact with the fixed mold;
Obtain, molding machine mold clamping device. 2. A movable plate on which a movable mold is mounted, and a fixed plate on which a fixed mold is mounted opposite to the movable mold.
And the surface of the fixing plate opposite to the surface on which the fixed mold is mounted.
A cylinder having one end fixed to the opposite surface, a piston sliding in the cylinder, and a through-hole provided in the fixed plate;
One end is fixed to the moving plate, and the other end is
The moving plate is fixed to the fixed plate.
A hollow cylinder rod for guiding the cylinder, a nut rotatably mounted on the other end of the cylinder, and one end fixed to the piston,
Screw rod screwed into the cylinder , a rotation device for rotating the nut, and the cylinder
By applying hydraulic pressure inside and pressing the piston
A pressure intensifier for bringing the movable mold into close contact with the fixed mold;
Obtain, molding machine mold clamping device. 3. A fixed plate on which a fixed die is mounted, and a serial plate arranged at a predetermined distance from the fixed plate.
Cylinder plate, disposed between the fixed plate and the cylinder plate
Then, a movable mold is mounted on the surface facing the fixed plate.
The moving plate to be attached is inserted into a through hole provided in the moving plate,
It is installed between the fixed plate and the cylinder plate.
Tie bar, a cylinder fixed to the cylinder plate, a piston sliding in the cylinder, a nut rotatably mounted on the cylinder plate, and screwed to the nut so as to be able to advance and retreat, one end of which moves.
Fixed to the plate and the other end to the piston
Screw rod, rotating device for rotating the nut, and the cylinder
By applying hydraulic pressure inside and pressing the piston,
Equipped with a pressure intensifier for bringing a moving mold into close contact with the fixed mold
That, molding machine mold clamping device.