JPH07132517A - Mold clamping device for molding machine - Google Patents

Abstract

PURPOSE:To reduce installation cost and maintenance cost, simplify a structure, and improve accuracy of stopping position by a clamping device wherein high speed mold opening/closing is performed based on combination of a screw bar and a pressure increasing hydraulic cylinder by a small ball screw and a servo motor having a small capacity, and pressure increase mold clamping is performed by the hydraulic cylinder. CONSTITUTION:A moving mold 1 is mounted on a moving plate 2 and a fixed mold 3 is mounted on a fixing plate 4. A piston 6 is mounted on one end of an opening/closing cylinder rod 7, whose other end is mounted on the moving plate 2, of the moving plate 2. The piston 6 is housed in a cylinder 5, which operates the moving plate, in a reciprocating way. A pressure increasing device 12, which is mounted on the piston 6, allows the piston 6 to reciprocate at a high speed by a screw bar 9, supplies hydraulic pressure to the cylinder 5, and clamps with pressure the moving mold 1 to the fixed mold 3 by the piston 6, is connected to the side of a piston rod of the cylinder 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of 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 mold opening of a molding machine must be carried out quickly and surely in order to shorten a work cycle and stabilize a molded product. FIG. 9 shows one cycle in the foam molding operation. According to the figure, in the molding work, high-speed mold closing, cracking stop, raw material filling, re-mold closing,
Intensification mold clamping, heating, cooling, mold opening, product ejection, and remolding are performed in sequence. In the heating / cooling step, the pressure boosting cylinder is operated to clamp the die at a high pressure so that the die does not open due to the expansion pressure of the raw material resin. on the other hand,
At the time of high-speed mold closing or high-speed mold opening, the ball screw is actuated to move the fixed mold quickly, and the mold opening / closing one cycle operation is quickly performed.

Next, a conventional example will be described. The first conventional example (not shown) uses a ball screw and a servomotor to perform mold opening and mold clamping and boosting mold clamping. In this case, the ball screw directly performs mold clamping and boosting mold clamping. It is necessary to increase the strength of the ball screw, and as a result, the diameter of the ball screw becomes large, the servo motor also has a large capacity, and the electric equipment cost and power consumption also increase.

The second conventional example (not shown) uses a ball screw, a small capacity servomotor and a speed reducer. The speed reducer is not operated when the mold is opened and closed, and the rotation of the small capacity servomotor is prevented. When transmitting directly to the ball screw to open and close the mold at high speed, and when performing pressure clamping, the electromagnetic clutch or air clutch is used to switch the speed reducer to reduce the high-speed rotation of the small-capacity servo motor and reduce the speed simultaneously. The output of is increased 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 not only to be large enough to withstand the pressure increase by the speed reducer but also requires a speed reducer and an electromagnetic clutch, resulting in high equipment costs.

A third conventional example (not shown) is a method of performing die opening / closing and pressure boosting die clamping with a hydraulic cylinder. A hydraulic cylinder can easily obtain a high pressure compared to a ball screw, but on the other hand, a hot water temperature control or a cracking cylinder is required to perform a highly accurate stop operation, and for die protection, In the case of hydraulic pressure, a low pressure mold closing device is required at the time of mold closing, which causes a problem that the hydraulic circuit becomes complicated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such drawbacks of the prior art. An object of the present invention is to combine a ball screw, a hydraulic cylinder, and a pressure boosting cylinder to obtain a small diameter ball screw. By using a small capacity servo motor to open and close the mold at high speed and a hydraulic cylinder to perform pressure boosting mold clamping work, equipment cost and maintenance cost are low, and the structure is simple and the mold clamping device has high position accuracy. It is intended to be provided.

[0007]

A mold clamping device for a molding machine according to claim 1, wherein a movable plate 2 having a movable mold 1 mounted thereon, a fixed plate 4 having a fixed mold 3 mounted thereon, and a movable plate operation A cylinder rod 7 mounted on a piston 6 that reciprocates in a cylinder 5 for opening and closing the moving plate 2, and a screw rod 9 mounted on the piston 6 for performing high-speed reciprocating motion of the piston 6. 5, a hydraulic pressure is supplied to 5 and a pressure increasing device 12 is used to clamp the moving mold 1 to the fixed mold 3 by the piston 6 and clamp the mold.

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

The mold clamping device of the molding machine according to claim 2 is the first embodiment in which claim 1 is more specific, and is a movable plate 2 on which the movable mold 1 is mounted, and a fixed mold 3 A fixed plate 4 on which is mounted, a cylinder 5 fixed to the fixed plate 4 on the opposite side of the fixed mold 3, and a piston 6 which slidably supports the movable plate 2 and reciprocates in the cylinder 5. A cylinder rod 7 having the same, a nut 8 mounted on the piston 6, a screw rod 9 screwed into the nut 8 so as to be able to be screwed forward and backward, and arranged parallel to the cylinder rod 7, and a screw rod 9. The rotating device 10 for rotating and the pressure-increasing pressure oil chamber 11a of the cylinder 5 are supplied with hydraulic pressure to move the piston 6 in the direction away from the fixed plate 4, and the movable mold 1 is clamped to the fixed mold 3 with pressure increasing. Booster
It is characterized by being composed of 12 and.

In the high-speed die 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. As a result, the movable plate 2 which is slidably mounted on the cylinder rod 7 and has the movable mold 1 performs the high-speed mold opening / closing operation with respect to the fixed mold 3. On the other hand, in the pressure boosting mold clamping process, the pressure booster 12 is operated to activate the cylinder 5
The hydraulic pressure 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 moving die 1 approaches the fixed die 3) and the fixed die 3 is moved. Then, the moving die 1 is clamped with the pressure increasing die. 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 has a strength sufficient to move the moving plate 2 having the moving die 1 at a high speed, and the screw rod 9 may have a small diameter. In the figure, the cylinder rod 7 is hollow and the threaded rod 9 is inserted therein, but the invention is not limited to this, and both may be arranged in parallel.

According to a third aspect of the present invention, there is provided a mold clamping device for a molding machine, including a movable plate 2 having a movable mold 1, a fixed plate 4 having a fixed mold 3 mounted thereon, and an opposite side of the fixed mold 3. A cylinder 5 fixed to a fixed plate 4, a cylinder rod 7 having a piston 6 that slidably supports the moving plate 2 and reciprocates in the cylinder 5, and a nut 8 attached to the cylinder 5. A screw rod 9 which is screwed into the nut 8 so as to be able to advance and retract, is attached to the piston 6, and is arranged in parallel to the cylinder rod 7, a rotating device 10 for rotating the nut 8, and a pressure increasing of the cylinder 5. A pressure increasing device 12 for supplying pressure oil to the side pressure oil chamber 11a to move the piston 6 in a direction away from the fixed plate 4 to clamp the moving die 1 to the fixed die 3
It is characterized by being composed of and.

The mold clamping device according to claim 3 has the same operating principle as the mold clamping device according to claim 2 with a slight difference in structure. That is, the high-speed mold opening / closing operation operates the rotating device 10 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. As a result, the movable plate 2 is slidably supported by the cylinder rod 7 and has the movable mold 1.
Will open and close the fixed mold 3 at high speed.
On the other hand, in the pressure boosting mold clamping step, the pressure boosting cylinder 12 is operated to supply the hydraulic pressure to the pressure boosting side pressure oil chamber 11a of the cylinder 5 so that the piston 6 is separated from the fixed plate 4 (that is, the movable die 1 is fixed. The die 3 is moved in the direction approaching the die 3) and the moving die 1 is clamped to the fixed die 3 under pressure. 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 has a strength sufficient to move the moving plate 2 having the moving die 1 at a high speed, and the screw rod 9 may have a small diameter.

A mold clamping device for a molding machine according to a fourth aspect of the present invention is provided on a pedestal 13 so as to stand upright, a fixed plate 4 on which a fixed mold 3 is mounted, a cylinder plate 15 on which a cylinder 5 is mounted, and a fixed plate 4. A tie bar 14 installed between the cylinder plate 15 and the movable plate 2 reciprocally slidably mounted on the tie bar 14, one end of which is mounted on the movable plate 2 on the opposite side of the movable mold 1 and the other end. The piston 6 is attached to the tie bar 14, the screw rod 9 arranged in parallel with the tie bar 14, the nut 8 screwed onto the screw rod 9, the rotating device 10 for rotating the nut 8, and the cylinder plate 15. Hydraulic pressure is supplied to the rotation holding portion 16 that rotatably holds the nut 8 and the tip side pressure oil chamber 11b of the cylinder 5 to move the piston 6 in the direction of the fixed mold 3 to move the fixed mold 3 to the fixed mold 1. Intensifier 1 for clamping the pressure It is characterized by being composed of 2 and.

The mold clamping device according to claim 4 is different from the mold clamping device according to claims 2 and 3 in structure, but the operating principle is similar. That is, the high-speed mold opening / closing operation operates the rotating device 10 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 attached to the tip of the screw rod 9 also moves forward and backward at high speed, and the high speed mold is opened and closed. On the other hand, in the pressure-increasing die clamping process, the pressure-increasing device 12 is operated to supply hydraulic pressure to the pressure-increasing side pressure oil chamber 11b of the cylinder 5 to cause the piston 6 to move.
Is pushed out, and the movable mold 1 is clamped to the fixed mold 3 by pressure increasing.

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

In addition to this, in the first to third aspects, the pressure boosting die clamping is performed through the cylinder rod 7, and the screw rod 9 is not subjected to the pressure boosting. The moving plate 2 mounted with is thick enough to withstand the high-speed opening / closing operation, whereas in the case of claim 4, since the increased pressure is applied to the screw rod 9, the strength enough to withstand the increased pressure is required. Different in required points.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mold clamping device for a molding machine according to the present invention will be described below with reference to the illustrated embodiments. The molding machine includes all devices such as a foam molding machine and an injection molding machine that use a fixed mold and a moving mold. 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 should be noted that components having the same function are denoted by the same reference numerals throughout the drawings.

A first embodiment of the mold clamping device of the present invention is shown in FIGS.
Follow the instructions below. 1 is a moving mold, 2 is a moving plate,
Reference numeral 3 denotes a fixed mold, and 4 denotes a fixed plate. As described above, the fixed mold 3 is fixed to the inner surface side of the fixed plate 4, and the movable mold 1 faces the fixed mold 3 to move the movable plate. It is fixed to the inner surface of 2. The fixed plate 4 is a mount
It is erected on 13 and fixed mold 3 is moved mold 1
Are abutted and separated from each other. Reference numeral 5 denotes a cylinder, which is mounted on the fixed plate 4 on the side opposite to the fixed mold 3. A piston 6 is reciprocally mounted in the cylinder 5. Reference numeral 7 is a cylinder rod, one end of which is attached to the moving plate 2 and the other end of which is attached to the piston 6, and is inserted into the through hole 18 of the attachment portion 17 of the fixed plate 4.

Reference numeral 8 denotes a nut, which is attached to the piston 6. The nut 8 may be an ordinary spiral screw whose inner surface is recessed, but in the present embodiment, a ball nut is used for smoother rotation. Reference numeral 9 is a threaded rod that is screwed into the nut 8 so as to be able to advance and retract. A ball screw is used in this embodiment. One end of the screw rod 9 is rotatably held by the 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, the fixed plate 4
It is fixed to the mounting portion 17 of. A pressure increasing side pressure oil chamber 11a is 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 is a timing pulley 10a,
It is composed of a drive pulley 10b, a servo motor 10c, and a timing belt 10d. FIG. 2 is a front view of the rotating device 10. The timing pulley 10a is attached to one end of the screw rod 9, and the drive pulley 10b is attached to the drive shaft of the 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 applied to the timing pulley 1c.
It is transmitted to 0a.

Reference numeral 12 is a pressure boosting device, which is composed of a cylinder body 12a, a pressure boosting piston 12b, a pressure boosting rod 12c, a small diameter cylinder portion 12d and a pressure oil sump 12e. The pressure boosting piston 12b reciprocates in the cylinder body 12a. Slide freely, booster rod 1
2c slides back and forth in the small diameter cylinder portion 12d together with the pressure boosting piston 12b. The pressure oil sump 12e is filled with pressure oil, and the open end of the pressure oil sump 12e opens at the base of the small diameter cylinder portion 12d. The tip of the small-diameter cylinder portion 12d is connected to the pressure oil inlet 23 via a hydraulic line, and the pressure oil is increased in the pressure oil chamber 11
It is designed to be supplied within a.

Reference numeral 24 denotes an oil pressure switching valve, which is connected to both ends of the cylinder body 12a and serves to reciprocate the pressure boosting piston 12b. FIG. 3 is a partial detailed view of FIG. The eject mechanism 25 is composed of the following members. A fixed eject plate 36 is disposed on the back surface of the fixed plate 4, and an eject guide 28 is installed between the fixed eject plate 36 and the fixed plate 4. The fixed eject plate 36 is fixed by the eject guide 28. Are fixed to the fixing plate 4.

An eject actuating plate 30 is reciprocally supported by the eject guide 28. Reference numeral 26 denotes an eject nut, which is attached to the eject actuating plate 30 and has an eject screw 27 screwed therein. 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 attached to the other end projecting portion of the eject screw 27, and is rotationally driven by an eject timing belt 35.

Reference numeral 29 is an ejecting rod mounted on the ejecting plate 30, which is a rear hole 2a formed in the fixed plate 4.
It is inserted into the steam chamber 37 inside the fixed plate 4 through. 31 is an eject plate, which is an eject actuating rod 29
It is attached to the tip of the. Reference numeral 32 denotes an eject pin, which projects through the eject through hole 3a formed in the fixed mold 3 toward the cavity surface side of the eject through hole 3a. Reference numeral 33 denotes a return spring, which presses and urges the eject pin 32 so as to pull it 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 drawing showing a mold open state. First, a description will be given of the case of performing high-speed mold closing from this state to the cracking position. The servomotor 10c is driven to rotate the screw rod 9 at high speed via the timing pulley 10a. Screw rod 9
Since the nut 8 screwed with is fixed to the piston 6 of the cylinder rod 7, the nut 8 is
It is screwed in 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 die 1 move together with the nut 8 at high speed in the fixed die 3 direction. At this time, the pressure-increasing side pressure oil chamber 11a is expanded, so the hydraulic pressure switching valve 24 is in the (a) position as shown in the figure, and the pressure-increasing piston 12b is pulled back to open the outlet of the pressure oil sump 12e, so that the pressure oil Is freely sucked into the pressure increasing side pressure oil chamber 11a from the pressure oil reservoir 12e without resistance.

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

The position where the movable mold 1 comes into contact with the fixed mold 3 is detected, and the pressure is increased. In the pressure boosting step, the hydraulic pressure switching valve 24 is operated to switch from the (a) position to the (b) position, the pressure boosting piston 12b is moved forward, and the pressure boosting rod 12c is moved forward into the small diameter cylinder portion 12d. When the tip of the pressure boosting rod 12c closes the opening of the pressure oil sump 12e, the small diameter cylinder portion 12d, the pressure oil pipeline and the pressure increasing side pressure oil chamber 11a constitute a closed circuit, and the pressure oil in the small diameter cylinder portion 12d is Pressure increasing side pressure oil chamber through pressure oil pipe 1
It is supplied to the inside of 1a, the piston 6 is separated from the fixed plate 4, and the moving mold 1 is further pressed to the fixed mold 3 (right side in the figure) side. (Intensification mold clamping)

After performing the pressure-intensifying mold clamping in this manner, 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. The moving mold 1 (or the fixed mold 3) is allowed to flow through the cavity to the steam chamber 37. Thereby, the raw material beads filled in the cavity are heated and expanded to fill the inside of the cavity. After that, 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, operate the hydraulic switching valve 24 in the reverse direction to move from the (b) position.
(a) Switch to the position and retract the pressure boosting piston 12b to open the pressure oil sump 12e.

Next, the servo motor 10c is rotated in the reverse direction, and the operation in the opposite direction to that described above is performed to move the moving plate 2 to the left side in the drawing, separating the moving mold 1 from the fixed mold 3 and opening the high speed mold. I do. At this time, the piston 6 moves to the left side in the figure, and the pressure increasing side pressure oil chamber 11a is contracted. Fixed mold side pressure oil 11a
The pressure oil in the pressure-increasing side pressure oil chamber 11a is returned to the pressure oil sump 12e through the conduit. At this time, the hydraulic switching valve 24
Has already been switched to the (a) position and the pressure boosting piston 12b has been pulled back (left in the figure) as described above, and the pressure oil sump 12e is open, so that pressure oil can return without resistance. It is supposed to be done.

After the high speed mold opening is performed in this way, the mold opening speed is once lowered, during which the eject mechanism 25 is operated to project the product, and the molded product 38 is taken out from the mold 3 (or 1), After that, high-speed mold opening is performed again. The servo motor 10c is stopped when the remolding is completed. 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, and it has been described that the mold re-closing after the cracking is stopped is performed by the servo motor 10c, but the invention is not limited to this, and the pressure booster 12 can be used to re-mold. It goes without saying that it may be closed. Further, although it has been described that the pressure increase device 12 is switched by the hydraulic pressure switching valve 24, it is not limited to this, of course,
It is also possible to use a motor / screw mechanism as described below.

Next, a second embodiment of the present invention will be described with reference to FIGS. The description of the points that are the same as those of 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. 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 description of the same parts as those described above will be omitted. The structure of the third embodiment is slightly different from that of the first and second embodiments. The fixing plate 4 is erected on one end of the pedestal 13 and the cylinder plate 15 is erected on the other end of the pedestal 13. . A tie bar 14 is installed between the fixed plate 4 and the cylinder plate 15, and the moving plate 2 is slidably held by the tie bar 14. The cylinder 5 is fixed to the rear surface of the cylinder plate 15 via a fixed rod cover 21a, and the pressure oil inlet 23 provided in the head cover 19 and the small diameter cylinder portion 12d are connected by a pressure oil pipe line.

Reference numeral 16 is a rotation holding portion, which is composed of 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 a bolt, and are rotated by the timing belt 10d. Sleeve 1
6a is rotatably held in the 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, and the nut 8
The rotation of the moving plate 2 causes the moving plate 2 to move forward and backward.

The operation of the third embodiment will be described with reference to FIGS. Similar to the above, by switching the hydraulic pressure switching valve 24 to the (a) position, the pressure boosting piston 12b is moved to the left side in the drawing, the inlet of the hydraulic pressure reservoir 12e is opened, and the pressure oil is stored in the pressure boosting side pressure oil chamber 11b of the cylinder 5. Be free to supply. Then, 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 side in the drawing (fixed mold 3
Side) to bring the moving mold 1 close to the fixed mold 3. At this time, the pressure oil in the pressure oil sump 12e is automatically sucked into the pressure increasing side pressure oil chamber 11a through the pipe line. Below, stop the cracking position, fill the raw material, close the mold again, clamp the booster mold, heat
Cooling process, high speed mold opening, product ejection, remolding etc. are the first
Same as the embodiment. Also in this case, when the pressure boosting piston 12b is actuated in the pressure boosting mold clamping to move the piston 6 forward, the nut 8 screwed into the screw rod 9 rotates, so the servo motor 10c is turned off. As a result, the servomotor 10c rotates with no load, and the pressure-increasing die clamping is performed by hydraulic pressure.

FIG. 9 is a flow chart in the present invention. The screw rod (9) (ball screw) is used for both high-speed mold closing and remolding after the cracking is stopped and mold opening, and the pressure boosting cylinder 12 is used for the pressure boosting cylinder. It may be used for tightening, but the screw rod (9) (ball screw) is used for high-speed mold closing and mold opening, and the pressure boosting cylinder 12 is used for both remolding after stopping cracking and pressure boosting mold clamping. You may do it.

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

[0037]

According to the first to third aspects of the present invention, the movable plate on which the movable mold is mounted can be opened and closed at high speed with respect to the fixed mold by rotating the screw rod or the nut.
In the pressure boosting mold clamping step, the pressure boosting mold is clamped by the pressure boosting cylinder so that the pressure boosting is applied only to the cylinder rod as a tension and no force is applied to the screw rod. Therefore, the screw rod has the advantage that it is sufficient to move the moving plate on which the moving die is mounted at a high speed, and the screw rod may have a small diameter. Other,
Since the high-speed mold opening / closing operation is performed only with a screw rod or a nut, the precision of the high-speed mold opening / closing operation at the cracking stop position, and the accuracy of the switching position from re-mold closing to pressure boosting mold clamping operation are dramatically improved. There are also advantages. In addition, you can use a servo motor as a rotating device,
The pressure can be adjusted freely, and it has great control advantages.

The mold clamping device of claim 4 is structurally different from those of claims 1 to 3. In this case as well, the high-speed mold opening / closing operation is performed by rotating the nut and advancing / retreating the screw rod screwed into the nut. Switching from mold closing to boosting mold clamping operation The position accuracy is dramatically improved, and because a servo motor can be used as a rotating device, speed and pressure can be adjusted freely, and there are great advantages in control. Is. In this case, the screw rod also serves as the piston rod, and the increased pressure is applied to the screw rod as a force in the compression direction in the pressure-increasing die clamping step. Therefore, unlike claims 1 to 3, the threaded rod is basically required to have a thickness capable of withstanding the increased pressure. However, even in this case, the rotating device is kept free, Since the increased pressure is not applied directly to the nut but only to the threaded rod, a threaded rod with a smaller diameter than the conventional example will suffice.

[Brief description of drawings]

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

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

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

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

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

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

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

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]

 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 side pressure oil chamber 12 ... Pressure increasing apparatus

Claims (4)

[Claims] 1. A moving plate mounted with a moving mold, a fixed plate mounted with a fixed mold, and a cylinder rod mounted on a piston reciprocating in a cylinder for moving the plate to open and close the moving plate. ,
It is composed of a threaded rod mounted on the piston for performing high-speed reciprocating motion of the piston, and a pressure increasing device for supplying hydraulic pressure to the cylinder and clamping the moving mold to the fixed mold by the piston. The mold clamping device of the molding machine, which is characterized by 2. A moving plate on which a moving mold is mounted, a fixed plate on which a fixed mold is mounted, a cylinder fixed to the fixed plate on the opposite side of the fixed mold, and the moving plate slidably supported. And a cylinder rod having a piston that reciprocates in the cylinder, a nut mounted on the piston, and a screw rod screwed into the nut so as to be screwed forward and backward and arranged parallel to the cylinder rod. , A rotating device that rotates the screw rod and a pressure increasing device that supplies hydraulic pressure to the pressure increasing side pressure oil chamber of the cylinder to move the piston in the direction away from the fixed plate and clamps the moving mold to the fixed mold. A mold clamping device for a molding machine, which is characterized in that 3. A moving plate on which a moving mold is mounted, a fixed plate on which a fixed mold is mounted, a cylinder fixed to the fixed plate on the opposite side of the fixed mold, and the moving plate slidably supported. And a cylinder rod having a piston that reciprocates in the cylinder, a nut attached to the cylinder, and a nut that is screwed into the nut so that the nut can be screwed forward and backward, and is attached to the piston and arranged parallel to the cylinder rod. Screw rod, rotating device that rotates the nut, and hydraulic pressure to the pressure oil chamber on the pressure-increasing side of the cylinder to move the piston in the direction in which the fixed plate separates, and the movable die is clamped to the fixed die. A mold clamping device for a molding machine, characterized in that it is configured with a pressure increasing device. 4. A fixed plate that is erected on a stand and has a fixed die, a cylinder plate that has a cylinder, a tie bar that is installed between the fixed plate and the cylinder plate, and a reciprocating slide on the tie bar. A movable plate freely mounted, one end of the movable plate opposite to the movable mold is mounted on the movable plate, the other end is equipped with a piston, and a screw rod is arranged in parallel with the tie bar, and a screw rod is screwed on the screw rod. Mounted nut, a rotating device that rotates the nut, a rotation holding portion that rotatably holds the nut with respect to the cylinder plate, and a piston to fix the piston by supplying hydraulic pressure to the pressure oil chamber on the tip side of the cylinder. A mold clamping device for a molding machine, comprising: a pressure increasing device for moving the movable mold to a fixed mold and increasing the pressure of the movable mold.