KR910001568B1 - Direct-pressure type mold clamping mechanism - Google Patents

Abstract

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Description

[Name of invention]

Direct clamping mechanism

Detailed description of the invention

[Technical Field]

The present invention relates to a motor-driven direct pressure clamping mechanism in an injection molding machine.

Background Technology

The injection molding machine is equipped with a toggle type clamping mechanism which connects a drive source and a movable platen through a toggle link, or a direct pressure type clamping mechanism which is directly connected to both. Tighten.

Therefore, in order to mold fastening, the mold needs to be fastened by a large force. Therefore, one requirement of the driving source of the mold clamping mechanism is that a large mold clamping force can be generated. Further, in injection molding, it is desired to shorten the time required for manufacturing a molded article, that is, cycle time. Therefore, the second requirement of the driving source is that the mold can be driven at high speed when the mold is opened and closed.

The toggle link opens and closes the mold at high speed and generates a large clamping force, so the toggle clamping mechanism meets the above two requirements. On the other hand, the direct pressure clamping mechanism has an advantage that, unlike the toggle mold clamping mechanism, mold thickness adjustment for compensating for the change in the mold thickness is unnecessary. However, the direct pressure clamping mechanism has difficulty in meeting the above two requirements. For example, in a direct pressure type fastening mechanism using a motor as a driving source, in order to meet the above two requirements, the capacity is very large, and therefore, an expensive motor must be used, and the manufacturing cost of the injection molding machine is significant. Defects occur.

[Initiation of invention]

Therefore, an object of the present invention is a direct pressure type driven by a motor that can perform mold closing and mold opening operation at high speed, and can also generate a required clamping force, without using a special motor having a particularly large capacity. In providing a clamping mechanism.

In order to achieve the above object, the direct pressure mold clamping mechanism of the present invention has a linear motion portion integrally movable with a movable platen, a rotary member, and rotates the rotary member of the linear motion member. Converting means for converting into linear motion, a motor for driving the rotating member of the converting means, vibration means for rotating the rotating member at high speed by transmitting rotation of the motor to the rotating member, and A reduction gear for reducing the rotation of the motor and increasing the rotational force so as to transmit such a great motor rotational force to the rotating member, and connecting the motor and the rotating member through either of the transmission means and the reducer. And a switching means for making it.

As described above, the present invention does not need to generate a particularly large driving force, but when the mold closing and mold opening need to move the movable platen at a high speed, the movable platen is driven by a motor through a transmission means. Although the speed and the movement amount may be small on one side, the mold clamping operation is performed by the motor output increased through the reducer when the mold clamping needs to generate a large clamping force. Therefore, a large capacity motor is required. Without this, mold clamping can be performed, and mold closing and mold opening operations can be performed in a short time. Therefore, an injection molding machine can be obtained economically and with a short cycle time.

In addition, since the maximum output torque of the motor is set to be small, when the mold protection is performed by applying a torque limit to the motor output during the mold protection, a small optimum mold protection force can be obtained.

BEST MODE FOR CARRYING OUT THE INVENTION

1 shows a direct pressure clamping mechanism according to a first embodiment for carrying out the present invention, wherein reference numeral 1 is a movable platen, reference numeral 2 is a fixed platen, and the two platens 1 and 2 are provided. The mold spheres 3 and 4 are respectively attached. If the stationary platen 2 is fixed to the base 21 of the injection molding machine, the movable platen 1 is a rear platen (not shown) and the stationary platen 2 not fixed to the base 21 of the injection molding machine. According to the tie (not shown) extended between them, it is able to slide left and right in 1st degree. Reference numeral 5 denotes a nut fixing base fixed to the movable platen 1 with a bolt or the like, and a nut mounting plate 6 is fixed to one end of the nut fixing base 5 by a bolt or the like. The nut nut 7 is fixed to the nut mounting plate 6 by bolts or the like, and these elements 1, 5, 6 and 7 have an integral structure.

A bowl screw 8 is screwed into the bowl nut 7, and the bowl screw 8 is mounted so that its shaft center almost coincides with the center of the movable platen 1. That is, by rotating the bowl screw 8, the movable platen 1 is moved through the bowl nut 7, the nut mounting plate 6, and the nut fixing base 5, whereby the molds 3 and 4 When sieving, the screw 8 is positioned so that the molds 3 and 4 are equally sieved.

The bowl screw shaft 8a and the bowl screw shaft 8a integral with the bowl screw 8 are rotatably held by the base 21 of the injection molding machine (or the rear platen fixed to the base) through the thrust bearing 20. . The teeth 9, 13 are fixed to the bowl screw shaft 8a, and the teeth 10 are engaged with the teeth 9, and the teeth 10 are separated from the drive shaft 12 by the electromagnetic clutch 11. It is connected freely. The gear 13 is engaged with the idler 14, and the idler 14 is engaged with the gear 15, which is also separated from the drive shaft 12 by the electromagnetic clutch 16. Is connected. Thus, the drive shaft 12 is connected to the motor 17. Moreover, the brake apparatus 19 is formed in the axis | shaft with which the tooth | gear 18 which meshes with the tooth | gear 9 was connected. Although not shown, the motor 17 and the brake device 19 are fixed to the base 21 of the injection molding machine, and the idler 14 is supported on the base 21.

In the present embodiment, the gear 9 and the gear 10 constitute a reduction gear, decelerate the rotation of the drive shaft 12, and greatly rotate the torque so as to be transmitted to the bowl screw shaft 8a. On the other hand, the gear 13, the idler 14, and the gear 15 constitute a transmission means for transmitting the rotation of the drive shaft 12 to the bowl screw shaft 8a at a rotational speed ratio of 1: 1.

In the figure, reference numeral 100 denotes an apparatus for driving control of the clutches 11 and 16, the motor 17, and the brake apparatus, and the apparatus 100 can be constructed by conventional techniques, and thus description thereof is omitted.

Next, the operation of the mold clamping mechanism of the present embodiment will be described.

First, when closing the mold, the clutch 11 is turned off, the drive shaft 12 and the gear 10 are separated, while the clutch 16 is turned on to connect the drive shaft 12 and the gear 15 to each other. In addition, the brake device 19 is turned off. Thus, when the motor 17 is rotated in the mold closing direction, the bowl screw is driven through the drive shaft 12, the clutch 16, the gear 15, the idler 14, the gear 13, and the bowl screw shaft 8a. (8) rotates at a high speed. Therefore, the nut 3, which is screwed with the bowl screw 8, is advanced so that the mold 3 mounted on the nut mounting plate 6 and the nut fixing base 5 integrally with the movable platen 1 is mounted. Move in the mold closing direction (from right to left in the first diagram). Thereafter, when the mold 3 reaches the mold protection start position, the rotation speed of the motor 17 is lowered to drive the mold 3 at the mold protection speed.

Thus, when the molds 3 and 4 reach the position touched, the clutch 16 is turned off, the connection between the drive shaft 12 and the gear 15 is released, and the brake device 19 is turned on. Fix the rotation of the bowl screw (8). Next, the clutch 11 is turned on, the drive shaft 12 and the gear 10 are connected, and the brake device 19 is turned off. Thus, the rotation of the motor 17 is decelerated and transmitted to the bowl screw shaft 8a through the drive shaft 12, the clutch 11, the gear 10, and the gear 9, so that the bowl screw 8 is slowed down. To rotate. With the rotation of the bowl screw 8, as described above, the mold 3 moves in the mold closing direction to sift the molds 3 and 4. At this time, by the gears 10 and 9, the rotational speed of the motor 17 is reduced, and since the rotational force is amplified, it is possible to generate a large clamping force and to reach a position for generating the set clamping force. When detected by a suitable sensor, the brake device 19 is turned on, the clutch 11 is turned off, and the driving of the motor 17 is stopped.

Thus, when mold closing is performed after the end of injection and holding pressure, the brake device 19 is turned off, the clutch 16 is turned on, and the motor 17 is opened at the mold separation speed in the mold opening direction (reverse). Rotate to rotate the bowl screw 8 through the clutch 16, the drive shaft 12, the gear 15, the idler 14, the gear 13, and the bowl screw shaft 8a in the opposite direction to mold closing. Rotate Thereafter, when the mold 3 reaches the acceleration position, the motor 17 is rotated. Then, when the mold 3 reaches the deceleration position, the motor 17 is decelerated. In addition, when the mold 3 reaches the mold closing completion position, the driving of the motor 17 is stopped, and the mold closing, mold clamping, and mold opening operations are finished once.

In addition, in the above embodiment, although the gear 18 engaging the brake device 19 with the gear 19 is formed to be fixed, the bowl screw shaft 8a may be directly fixed. In addition, the clutch 11 does not necessarily need to be formed between the drive shaft 12 and the gear 10, for example, the clutch 11 is between the gear 15 and the gear 10 of the drive shaft 12. It is also possible to form a clutch in place of, so that the gear 10 is directly fixed to one side of the drive shaft 12. A clutch instead of the clutch 16 may be formed between the bowl screw shaft 8a and the gear 13 and the gear 15 may be directly fixed to the drive shaft 12.

Moreover, the motor 17 can also be comprised by a servo motor. In this case, the servo motor operates to hold the mold 3 at a predetermined position at the time of transition from mold closing to mold clamping and at mold clamping, and therefore it is not necessary to form the brake 19.

2 shows a direct pressure clamping mechanism according to a second embodiment of the present invention, and the same members as those of the first embodiment are denoted by the same reference numerals. That is, reference numeral 1 is a movable platen, reference numeral 2 is a fixed platen, reference numerals 3 and 4 are molds, and reference numeral 5 is a nut base fixed to the movable platen 1.

This embodiment is mainly different from the first embodiment in which a set of bowl nuts 7 and a bowl screw 8 are used, and two sets of bowl nuts and bowl screws for coarse and fine motion are used. That is, the nut mounting plate 30 is fixed to the nut fixing base 5 with a bolt or the like, and the fine movement bowl screw 32 is screwed to the fine movement bowl nut 31 fixed to the nut mounting plate 30. have. Thus, the nut mounting plate 30 is able to slide in the direction of the molds 3 and 4 (left and right in FIG. 3) along the guide surface 35 of the coarse feed carriage 34. A coarse bowl nut 37 is fixed to the coarse feed carrier 34, and a coarse bowl nut 38 is screwed to the coarse nut 37, and the coarse bowl nut 38 is accompanied by the rotation of the coarse bowl screw 38. 37 and the coarse feed carrier 34 are made to move in the opening-closing direction of the metal mold | die 3,4. Then, the coarse feed carriers 3 and 4 are guided to move in the opening and closing directions of the molds 3 and 4 by guide rods and the like not shown. Further, a brake device 40 for preventing rotation of the coarse bowl screw 38 and the integral thread screw shaft 39 is fixed to the base of the injection molding machine, and one end of the bowl screw shaft 39 has an electromagnetic clutch ( It is connected to the shaft 43 of the gear 42 so that it can be interrupted | blocked through 41). Thus, the gear 42 meshes with the gear 45 driven by the motor 44.

The bearing plate 36 is integrally fixed to the coarse feed table 34. Thus, the fine-driving bowl screw 32 and the integral bowl screw shaft 33 extend through the bearing plate 36, and are held by the thrust bearing 46 disposed on the bearing plate 36. have. Further, one end of the bowl screw shaft 33 is connected to the spline shaft 49 via the clutch 48 freely. In addition, a brake device 47 fixed to the bearing plate 36 is arranged in an operating relationship with the bowl screw shaft 33. A tooth 50 is splined to the spline shaft 49, and the tooth 50 is engaged with the tooth 45 driven by the motor 44. Thus, the reduction ratio of the gear 45 and the gear 50 is set to a large value, and the gear 45 and the gear 50 constitute a reducer, while the gear 45 and the gear 42 rotate. A ratio of 1: 1 constitutes a transmission means.

Next, the operation of the mold clamping mechanism according to the second embodiment will be described.

First, when mold closing is performed, the clutch 48 is removed through the drive control device 100 and the clutch 41 is inserted. Thus, the brake device 47 is operated to fix the rotation of the fine motion bowl screw 32, while the brake device 40 is turned off. Thus, the motor 44 is driven in the mold closing direction, and the toothed screw shaft 39 and the coarse coarse threaded screw 38 are connected to each other through the gear 45, the toothed tooth 42, and the clutch 41. Rotate at high speed In the meantime, the fine-driving bowl screw 32 is driven off from the spline shaft 49 by the clutch 48 in the off state and fixed by the brake device 47 in the on state.

With the rotation of the coarse bowl screw 38, the bowl nut 37 and the coarse feed carriage 34 integral with the bowl screw 38 move in the mold closing direction, and are integral with the feed table 34. The bowl screw shaft 33 and the fine moving bowl screw 32, which are integrally movable through the bearing plate 36 and the brake device 47, also move in the same direction. At the same time, it is mounted on the movable platen 1 fixed through the nut fixing base 5 to the nut mounting plate 30 integral with the non-rotating bowl nut 32 for screwing with the non-rotating bowl screw 32. The mold 3 moves at high speed in the mold closing direction. At this time, the spline shaft 49 and the clutch 48 also move from the right side to the left side together with the coarse feed table 34.

Thus, when the mold 3 reaches the mold protection start position, the rotation speed of the motor 44 is lowered to the mold protection speed, and when the mold 3 touches the mold 4, the brake device 40 is operated. In this way, the rotation of the coarse bowl screw 38 is fixed, the clutch 41 is removed, the clutch 48 is inserted, and the brake device 47 is turned off. As a result, the rotation of the motor 44 is decelerated by the gear reducer made of the gear 45 and the gear 50, so that it can be moved finely through the spline shaft 49, the clutch 48, and the bowl screw shaft 33. It is transmitted to the bowl screw 32 to rotate it. With the rotation of the bowl screw 32, the nut mounting plate 30, the nut fixing base 5, which are integral with the bowl nut 31 and with respect to the coarse feed carrier 34, and the movable platen ( The mold 3 is moved in the mold closing direction through 1), so that the molds 3 and 4 are sifted together. At this time, since the rotational force of the motor 44 is amplified by the gear reducer by the gear 45 and the gear 50, a large clamping force is generated and the molds 3 and 4 are sifted by a large force. Thus, when the position at which the set clamping force is generated is reached, the brake device 47 is also operated to fix the rotation of the fine motion bowl screw 32 and the coarse motion bowl screw 38 to stop the driving of the motor 44. The clutch 48 is also removed.

Next, when performing mold opening, the brake device 47 is turned on, the brake device 40 is turned off, the clutch 41 is inserted, and the clutch 48 is removed. Thus, the motor 44 is rotated in the mold opening direction, the coarse bowl screw 38 is rotated at the mold separation speed, and the mold 3 is moved in the mold opening direction. In this way, when the mold 3 reaches the acceleration start position, the rotation of the motor 44 is accelerated. Then, when the mold 3 reaches the deceleration start position, the motor 44 is decelerated. Thereafter, when the coarse feed carrier 34 reaches a position corresponding to the mold closing start position of the mold 3, the brake device 40 is operated, the clutch 41 is removed, and then the brake device 47 is removed. The clutch 48 is turned off. As a result, the fine-driving bowl screw 32 rotates, and with this, the mold opening plate 30 is opened with respect to the coarse feed carrier 34 until the plate-locking operation start position of the plate 30 is reached. Is driven in the direction. As a result, the mold 3 reaches the mold opening completion position.

Then, in mold opening, the nut mounting plate 30 is first returned to the mold fastening operation start position of the plate on the coarse feed carrier 34, and then the coarse feed carrier 34 is opened to the mold opening completion position. It is also possible to change the operation sequence to return to the position of the coarse feed carrier 34 of.

In addition, when using a motor other than the servo motor in the motor 44, the respective positions of the coarse feed carriage 34 and the nut mounting plate 30 can be detected by various sensors to control the motor 44. There is a need. On the other hand, when the motor 44 is configured as a servo motor, the movement amount of the coarse feed table 34 and the nut mounting plate 30 with respect to the coarse feed table 34 is detected by a position detector formed in the servo motor. As such, various sensors are not necessary.

As described in the first and second embodiments, the present invention enables fast mold closing, mold opening speed, and large clamping force without using a motor with a particularly large capacity. Thus, since a motor with a particularly large capacity is not used, a torque limit for limiting the output torque of the motor can be optimally performed for protecting the mold during mold closing. That is, if the torque limit is to be applied to a motor having a large capacity, for example, a motor having a maximum output torque of 100 tons, the resolution of the torque limit is about 1/100, so the output torque at the time of the type protection is the lowest, 1 It is in tones. However, in the present invention which selectively uses the transmission means and the reduction gear, and changes the transmission path of the output torque of the motor to the movable platen at the time of mold opening and closing, and the mold fastening, the maximum output is 2-3 tons. A general purpose motor of a degree can also be used, and if the torque limit is applied to this motor, the output torque can be reduced to about 20 kg to 30 kg and an optimum mold protection pressure can be obtained.

[Brief Description of Drawings]

1 is a schematic diagram showing the main parts of a direct pressure type clamping device of a first embodiment of the present invention.

2 is a schematic view showing an apparatus according to a second embodiment of the present invention.

Claims (6)

A engrave mechanism of an injection molding machine, comprising: a linear movement member integrally movable with a movable platen, a rotation member, and a conversion for converting the rotational movement of the rotational member into the linear movement of the linear movement member. Means, a motor for driving the rotating member of the converting means, transmission means for rotating the rotating member at high speed by rotating the motor to the rotating member, and decelerating the rotation of the motor, And a reduction means for increasing the rotational force and transmitting the increased motor rotational force to the rotating member, and a switching means for connecting the motor and the rotating member through one of the transmission means and the reducer. Direct pressure clamping mechanism having a. The direct pressure type fastening mechanism according to claim 1, wherein the converting means is comprised of a bowl nut as the linear motion member and a bowl screw as the rotating member screwed to the bowl nut. 3. The transmission according to claim 1 or 2, wherein the switching means includes a clutch for disconnecting transmission of motor rotation to the rotary member through the transmission means and transmission of motor rotation to the rotary member through the reducer. A direct pressure fastening mechanism by means of a clutch for disconnecting gears. The direct pressure type clamping mechanism according to claim 1 or 2, comprising brake means for fixing the rotating member. 2. The driving means according to claim 1, wherein the converting means is splined to the coarse bowl screw nut mechanism having a coarse bowl screw which is driven by the motor via the transmission means, and is splined to the reducer and driven by the motor. A non-moving bowl screw nut mechanism having a fine-moving bowl screw, said switching means comprising: a clutch for disconnecting transmission of motor rotation to said coarse bowl screw, a brake means for fixing rotation of said coarse bowl screw, A clutch for disconnecting transmission of motor rotation to the fine movement bowl screw, and a brake means for fixing rotation of the fine movement bowl screw, and the fine movement nut slides in the axial direction with respect to the coarse nut. Freely excreted, this fine nut is mobile and integral with the movable platen. Straight apsik clamping mechanism is. The direct pressure mold clamping mechanism according to claim 1, 2 or 5, wherein the motor is a servo motor.

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