CN104476742A - Self-locking clamping mechanism of injection molding machine - Google Patents

Abstract

The inventiondiscloses a self-locking clamping mechanism of an injection molding machine. The self-locking clamping mechanism comprises a fixed mold plate (1), a movable mold plate (2), pull rods (3) and a mold moving oil cylinder (4), wherein the fixed mold plate (1) is fixed to one end of the pull rods (3), the movable mold plate (2) is arranged at the other end of the pull rods (3) in a sleeving manner, and a piston end of the mold moving oil cylinder (4) is connected with the movable mold plate (2) to drive the movable mold plate (2) to move. The clamping mechanism further comprises a mold locking structure, wherein the mold locking structure comprises rear nuts (5) corresponding to the pull rods (3) in a one-to-one mode, a large gear ring (6) and a power mechanism for driving the large gear ring (6) to rotate, the rear nuts (5) are screwed onto the pull rods (3), the outer edge of each rear nut (5) is in a gear shape, and the large gear ring is meshed with the rear nuts (5) respectively under the drive of the power mechanism and drives the rear nuts to rotate on the corresponding pull rods. The self-locking clamping mechanism does not need a mold locking oil cylinder and reduces the energy consumption of mold locking through self-locking between mechanisms.

Description

Self-locking mold clamping mechanism of injection molding machine

technical field

The invention relates to the field of injection molding machines, in particular to a self-locking mold clamping mechanism of the injection molding machine.

Background technique

The mold clamping structure of the existing two-platen injection molding machine mainly includes hydraulic direct locking type and compound type. Among them, the working process of the hydraulic direct locking type is mainly: firstly, the movable template is moved through the fast mold moving cylinder, and then the tie rod is locked through the brake structure, and then the mold is locked through the locking cylinder. The hydraulic direct locking type has automatic adjustment. mold function, but the required hydraulic system is relatively complex, the reliability is poor, and the occupied space has no obvious advantages compared with the three-platen injection molding machine, especially when the clamping force is large, four very large The oil cylinder has a large power, and it needs to consume a lot of energy when clamping the mold and maintaining the pressure. The typical composite type mainly drives the movable template to move quickly through the fast cylinder fixed on the static template to close the mold. Specifically, the movable template and the tie rod are relatively fixed by a positioning locking device, and then pulled by the clamping cylinder. The pull rod locks the mold tightly. In the composite type, the mold adjustment structure is generally divided into the following two types: 1. In the clamping cylinder, the position of the tie rod is finely adjusted to make the tooth top of the tie rod match the position of the tooth root of the gate nut, position and then lock the tie rod; 2. Adjust the position of the lock nut through the motor and other power mechanisms, so that the positions of the pull rod and the lock nut match, position and then lock the pull rod. In these two mold adjustment structures, the four tie rods or the lock nuts need to add a separate power device, and at the same time the oil circuit system becomes complicated, which increases the considerable cost, and is not suitable for small and medium-sized two-platen injection molding machines.

The patent (notification number: CN201313365Y) discloses a mold clamping device for a two-platen machine, including a movable platen, a tie rod, a fixed platen, a tie rod nut, a tie rod platen, a mold transfer cylinder, a brake cylinder, two-half opening and closing brake nuts, Brake positioning shaft, brake positioning shaft pressure plate, tie rod support, spring, high pressure mold clamping cylinder piston rod, high pressure mold clamping cylinder rear cover, high pressure mold clamping cylinder body, high pressure mold clamping cylinder front cover, guide copper sleeve, the device The connection between the four tie rods and the fixed platen is completely fixed. The brake part and the high-pressure mold clamping part are all designed on the rear side of the movable platen. When assembling the machine, the position of the lock thread of the four tie rods can be manually adjusted. After being adjusted in a unified position, it is completely fixed with the fixed formwork, the lengths of the force of the four tie rods are exactly the same, and the clamping force shared by the four tie rods is also exactly the same, so the deformation of the four tie rods is also exactly the same. This structure can improve the clamping accuracy, but there are still problems such as the need for a high-pressure mold clamping device, the structure of the hydraulic system is very complicated, and the energy consumption is high.

Contents of the invention

In view of this, the present invention provides a self-locking mold clamping mechanism of an injection molding machine to solve the technical problems of complex hydraulic systems and high energy consumption in the prior art, and proposes a self-locking mold clamping structure with low energy consumption to Solve the above-mentioned technical problems.

The technical solution of the present invention is to provide a self-locking mold clamping mechanism of an injection molding machine with the following structure, including a fixed template, a movable template, a pull rod and a mold transfer cylinder, the fixed template is fixed on one end of the pull rod, and the The movable template is sleeved on the other end of the pull rod, and the piston end of the mold transfer cylinder is connected with the movable template to drive the movable template to move;

The mold clamping mechanism also includes a mold locking structure. The mold locking structure includes rear nuts corresponding to the pull rods one by one, a large ring gear and a power mechanism for driving the large ring gear to rotate. The external thread of the nut, the rear nut is screwed on the pull rod, the outer edge of the rear nut is set in the shape of a gear, and a disc is installed on the mobile template, and the large ring gear is installed on the outer edge of the disc. A steel ball is arranged between the disk and the large ring gear, and the large ring gear and the disk are rotatably connected; driven by the power mechanism, the large ring gear meshes with the rear nuts respectively and drives the rear nuts to rotate on the corresponding pull rods.

With the above structure, compared with the prior art, the present invention has the following advantages: When the present invention is used to close the mold, under the action of the mold-moving oil cylinder, the movable template is in contact with the mold on the fixed template, and then driven by the power mechanism. The large ring gear rotates, thereby driving the rear nut meshed with it to rotate, thereby locking the mobile formwork, the rear nut is subjected to the reaction force of the movement formwork and the friction force with the pull rod, the rear nut and the pull rod are threaded, and the reaction force Under the friction and force, deformation occurs, thereby locking the rear nut. At the same time, the friction between the threads can produce a strong self-locking effect, and the large ring gear can amplify the torque of the power mechanism. The present invention does not need to use a clamping cylinder. The energy consumption of mold clamping is reduced by utilizing the self-locking between mechanisms.

As a preference, the mold clamping mechanism also includes a rear nut driving device corresponding to the rear nut one by one, and the rear nut driving device includes a pinion, a servo motor, a motor fixing frame, a linear guide rail and a The rotating part, the pinion gear meshes with the outer edge of the rear nut, the pinion gear is connected to the output shaft of the servo motor, the servo motor is installed on the motor fixing frame, and the linear guide rail is fixedly installed on the mobile template and connected to the large plane of the movable template. Vertically, the motor fixing frame is slidably connected to the linear guide rail, and the rotating part is connected to the motor fixing frame at the same time. When the mold is closed, the rear nut driving device drives the rear nut to be screwed into contact with the moving template. When the mold is opened, the rear nut is driven to leave to leave a space for mold opening. When the rear nut is driven to rotate, the motor is driven by the rear nut The fixed frame slides on the linear guide rail. Since the motor fixed frame is connected with the rotating part, the rotation of the rear nut will not be affected, and at the same time, the motor fixed frame can be smoothly driven to slide.

Preferably, the rotating part is a bearing, the inner ring of the bearing is axially fixedly connected with the rear nut, and the motor fixing frame is connected with the outer ring of the bearing. When the rear nut rotates, it drives the inner ring of the bearing to rotate accordingly. At this time, because the outer ring of the bearing is connected with the motor fixing frame, the inner ring and the outer ring of the bearing rotate relatively, which can drive the motor without affecting the rotation of the rear nut. The fixed frame moves back and forth.

Preferably, the large ring gear is provided with a plurality of toothed areas and a plurality of toothless areas, the plurality of toothed areas at least correspond to the rear nut one by one, and the toothed areas and the toothless areas are alternated arrangement. This design is used to prevent the teeth on the rear nut from interfering with the teeth on the large ring gear and cause failure. That is, when meshing is required, the toothed area is allowed to mesh with the rear nut, and when the rear nut moves back and forth quickly, the toothless area is allowed to engage. Corresponds to the rear nut to prevent tooth interference.

Preferably, the first tooth on the toothed area meshing with the rear nut is stretchable in the radial direction of the large ring gear, and is installed on the large ring gear through an elastic reset element. This design can prevent the first tooth from interfering with the rear nut and cause "stuck" and other phenomena, and plays a role of buffering, so that the subsequent meshing can be carried out effectively.

Preferably, the mold clamping mechanism further includes a controller, a torque sensor is installed on the output shaft of the servo motor, and both the servo motor and the torque sensor are electrically connected to the controller. Judging whether the torque sensor reaches the set value, if it reaches the set value, the servo motor is controlled to stop rotating, the servo motor responds quickly, and the fast forward and fast back of the rear nut can be realized.

Preferably, the power mechanism is a hydraulic motor, and a driving gear is connected to the hydraulic motor, and the driving gear meshes with the large ring gear. The hydraulic motor drives the large ring gear to rotate, and the driving gear is much smaller than the large ring gear, which plays a role of torque amplification.

Preferably, the movable template is provided with a displacement sensor for detecting the front and rear displacement of the movable template or the large ring gear. When the mold is opened, the displacement sensor detects that the large ring gear returns to its original position, and the hydraulic motor is controlled to stop working. In order to precisely control the hydraulic motor.

Description of drawings

Fig. 1 is the cross-sectional view of the self-locking mold clamping mechanism of the injection molding machine of the present invention;

Fig. 2 is a side view of the self-locking mold clamping mechanism of the injection molding machine of the present invention;

Fig. 3 is an axial side view of the self-locking mold clamping mechanism of the injection molding machine of the present invention;

As shown in the figure, 1. Fixed template, 2. Moving template, 3. Tie rod, 4. Transfer cylinder, 5. Rear nut, 6. Large gear ring, 6.1. Toothed area, 6.2. No toothed area, 7. Front nut, 8, body guide rail, 9.1, pinion gear, 9.2, servo motor, 9.3, motor fixing frame, 9.4, linear guide rail, 9.5, rotating part, 10, hydraulic motor, 11, controller, 12, torque sensor, 13. Displacement sensor.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the present invention is not limited to these embodiments.

The present invention covers any alternatives, modifications, equivalent methods and schemes made on the spirit and scope of the present invention. In order to provide the public with a thorough understanding of the present invention, specific details are set forth in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, for the sake of illustration, the drawings of the present invention are not completely drawn according to the actual scale, and are described here.

As shown in Figures 1, 2 and 3, a self-locking mold clamping mechanism of an injection molding machine involved in the present invention includes a fixed template 1, a movable template 2, a pull rod 3 and a mold transfer cylinder 4, the pull rod 3 One end is fixed on the fixed template 1, the movable template 2 is sleeved on the other end of the pull rod 3, and the piston end of the mold transfer cylinder 4 is connected with the movable template 2 to drive the movable template 2 to move;

The mold clamping mechanism also includes a mold locking structure, and the mold locking structure includes a rear nut 5 corresponding to the pull rod 3, a large ring gear 6, and a power mechanism that drives the large ring gear 6 to rotate. The pull rod 3 The external thread that cooperates with the rear nut 5 is provided on the top, and the described rear nut 5 is screwed on the pull rod 3. The outer edge of the rear nut 5 is set in a gear shape, and a disc is installed on the mobile template 2. The large The ring gear 6 is installed on the outer edge of the disc, and steel balls are arranged between the disc and the large ring gear 6, and the large ring gear 6 is rotatably connected to the disc; Engage and drive the rear nut 5 to rotate on the corresponding pull rod 3 .

The above constitutes the basic solution to solve the technical problem of the present invention. A further limitation is made on the above solution: the front nut fixes the pull rod on the fixed formwork. The mold-moving oil cylinder 4 is connected with the movable template 2 through the mold-moving cylinder hinge seat, positioning pin and universal head. Simultaneously, a fuselage guide rail 8 is provided for the mobile template 2 to slide on the fuselage. The pull rod 3 is divided into two parts, the part near the fixed template 1 is a polished rod structure, and the part near the movable template 2 is a screw structure, which is screwed with the rear nut 5; the number of pull rods 3 is consistent with the prior art, which is four. The installation of the large ring gear 6 can be realized in the following manner: a disk is installed on the mobile formwork, the large ring gear 6 is installed on the outer edge of the disk, steel balls are arranged between the two, and the large ring gear It is rotatably connected with the disc, just like the structure of the bearing; it is also possible to set a plurality of bearing columns arranged in a circle on the mobile template, and the large ring gear is sleeved on the bearing column, and the bearing column can not only position it but also Let it turn smoothly.

The mold clamping mechanism also includes a rear nut driving device corresponding to the rear nut 5 one-to-one. The rear nut driving device includes a pinion 9.1, a servo motor 9.2, a motor fixing frame 9.3, a linear guide rail 9.4 and a rear nut driving device. The rotating part 9.5 on 5, the pinion 9.1 meshes with the outer edge of the rear nut, the pinion 9.1 is connected to the output shaft of the servo motor 9.2, the servo motor 9.2 is installed on the motor fixing frame 9.3, and the linear guide rail 9.4 is fixed Installed on the mobile formwork 2 and perpendicular to the large plane of the mobile formwork 2, the motor fixing frame 9.3 is slidably connected to the linear guide rail 9.4, and the rotating part 9.5 is connected to the motor fixing frame 9.3 at the same time. When the mold is closed, the rear nut driving device drives the rear nut to be screwed into contact with the moving template. When the mold is opened, the rear nut is driven to leave to leave a space for mold opening. When the rear nut is driven to rotate, the motor is driven by the rear nut The fixed frame slides on the linear guide rail, and because the motor fixed frame is connected with the rotating part, it will not affect the rotation of the rear nut. The end of the linear guide rail 9.4 is provided with a directional fixing seat to prevent the motor holder 9.3 from sliding out of the linear guide rail 9.4, and also prevent the linear guide rail from naturally bending due to its own weight.

The rotating part 9.5 is a bearing, the inner ring of the bearing is axially fixedly connected with the rear nut, and the motor fixing frame 9.3 is connected with the outer ring of the bearing.

The large ring gear 6 is provided with a plurality of toothed areas 6.1 and a plurality of toothless areas 6.2, the plurality of toothed areas 6.1 at least correspond to the rear nut 5 one by one, the toothed areas 6.1 and the toothless areas 6.1 The tooth regions 6.2 are arranged alternately. A toothed area can be used to cooperate with the power mechanism. Of course, the power mechanism can also cooperate with the inner ring of the ring gear 6 (the inner ring is provided with internal teeth).

The first tooth on the toothed area 6.1 meshing with the rear nut 5 is stretchable in the radial direction of the large ring gear 6, and is installed on the large ring gear 6 through an elastic reset element. For example, a spring is used as the elastic return element.

The mold clamping mechanism also includes a controller 11, a torque sensor is installed on the output shaft of the servo motor 9.2, and both the servo motor 9.2 and the torque sensor 12 are electrically connected to the controller 11. When the rear nut 5 is in contact with the movable template 2, the torque rises, and the torque sensor detects that the torque rise reaches a set value, and the servo motor is controlled to stop rotating.

The power mechanism is a hydraulic motor 10 , a drive gear is connected to the hydraulic motor 10 , and the drive gear meshes with the large ring gear 6 . The large ring gear is driven to rotate by the hydraulic motor, and the number of teeth of the driving gear is far less than that of the large ring gear, which plays a role of torque amplification.

The mobile template 2 is provided with a displacement sensor 13 for detecting the front and rear displacement of the large ring gear 6. When the mold is opened, the displacement sensor detects that the large ring gear returns to its original position, and then controls the hydraulic motor 10 to stop working. "The large ring gear returns to its original position" means that the large ring gear turns back to its original position, and its first tooth can be used as the detection object.

The torque sensor, displacement sensor, servo motor and hydraulic motor are all connected with the controller to realize cooperative control.

Based on the above-mentioned self-locking two-platen machine mold clamping mechanism, a method for opening and closing molds of the self-locking two-platen machine mold clamping mechanism can be formed, including the following steps:

Clamping process:

1) The mold-moving cylinder pulls the movable template so that the movable template just contacts the mold on the fixed template, and the mold-moving cylinder stops working;

2) The rotation of the servo motor drives the pinion to rotate, and the pinion drives the teeth of the outer ring of the rear nut to rotate, and the rear nut is driven to rotate and at the same time move towards the moving template until the side of the rear nut is attached to the moving template. At this time, the servo motor stops working. The stop of the servo motor is controlled by the torque sensor. The torque sensor detects that the torque exceeds the set value and sends a feedback signal to make it stop working;

3) The power mechanism drives the large gear ring to rotate, and the rotation of the large gear ring drives the rear nut to rotate through the tooth engagement on the rear nut, and the rear nut rotates through its internal internal thread to mesh with the external thread on the pull rod, so that the deformation of the pull rod reaches the required level. The amount of deformation corresponding to the clamping force, complete the clamping, and maintain the clamping force until the end of the clamping. The power mechanism can use a hydraulic motor. After the hydraulic motor reaches the set value, the pressure sensor on the oil circuit detects the oil pressure and sends a feedback signal. The solenoid valve cuts off the oil circuit to keep the pressure of the hydraulic motor until the product cools down and the mold closing action is completed.

Mold opening process:

1) The power mechanism reverses, driving the large ring gear to rotate in reverse, thereby driving the rear nut to reverse, when the large ring gear returns to the original position, the clamping force disappears, and the power mechanism stops working;

2) The reverse rotation of the servo motor drives the pinion to rotate in the reverse direction, and the pinion drives the rear nut to continue to rotate in the reverse direction. The internal thread of the rear nut meshes with the outer nut of the pull rod, and moves away from the rear screw plate to the set position;

3) The mold-moving cylinder pushes the movable template, so that the mold on the movable template and the fixed template is separated to the rear nut side, and the mold-moving cylinder stops working.

The above is only an illustration of the preferred embodiments of the present invention, but should not be construed as a limitation on the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to vary. In a word, all kinds of changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

Claims (8)

1. the self-locking clamping of an injection machine, comprise solid plate (1), moving die plate (2), pull bar (3) and mould shifting oil cylinder (4), described solid plate (1) is fixed on one end of pull bar (3), described moving die plate (2) is sheathed on the other end of pull bar (3), and the piston end of described mould shifting oil cylinder (4) is connected to drive moving die plate (2) mobile with moving die plate (2); It is characterized in that:

Described clamping also comprises mould-locking structure, described mould-locking structure comprises and pull bar (3) back nut (5) one to one, bull gear (6) and the actuating unit driving bull gear (6) to rotate, described pull bar (3) is provided with the external screw thread coordinated with back nut (5), described back nut (5) is combined on pull bar (3), the outer rim of back nut (5) is arranged to gear-like, at the upper installation disk of moving die plate (2), described bull gear (6) is installed on disk outer rim, between disk and bull gear (6), steel ball is set, bull gear (6) and disk are rotatably connected, bull gear (6) all engages to back nut (5) respectively and drives back nut (5) above to rotate at corresponding pull bar (3) under the driving of actuating unit.

2. the self-locking clamping of injection machine according to claim 1, it is characterized in that: described clamping mechanism also comprises and back nut (5) back nut drive unit one to one, described back nut drive unit comprises pinion (9.1), servomotor (9.2), motor fixing frame (9.3), line slideway (9.4) and the tumbler (9.5) be arranged on back nut (5), described pinion (9.1) engages with back nut outer rim, pinion (9.1) is connected with the output shaft of servomotor (9.2), servomotor (9.2) is arranged on motor fixing frame (9.3), it is upper and vertical with moving die plate (2) that described line slideway (9.4) is fixedly mounted on moving die plate (2), described motor fixing frame (9.3) is slidably connected with line slideway (9.4), described tumbler (9.5) is connected on motor fixing frame (9.3) simultaneously.

3. the self-locking clamping of injection machine according to claim 2; it is characterized in that: described tumbler (9.5) is bearing; bearing inner race is connected with back nut axial restraint, and described motor fixing frame (9.3) is connected with bearing outer ring.

4. self-locking two trigger clamping according to claim 1; it is characterized in that: described bull gear (6) establishes multiple You Chi district (6.1) and multiple anodontia district (6.2); described multiple You Chi districts (6.1) at least with back nut (5) one_to_one corresponding, described You Chi district (6.1) and anodontia district (6.2) are alternately.

5. the self-locking clamping of injection machine according to claim 1; it is characterized in that: upper first tooth engaged with back nut (5) in described You Chi district (6.1) is scalable in bull gear (6) radial direction, is installed on bull gear (6) by elastic reset member.

6. the self-locking clamping of injection machine according to claim 2; it is characterized in that: described clamping also comprises controller (11); the output shaft of described servomotor (9.2) is provided with torque sensor, and described servomotor (9.2) and torque sensor are all electrically connected with controller.

7. the self-locking clamping of injection machine according to claim 1; it is characterized in that: described actuating unit is hydraulic motor (10); described hydraulic motor (10) is connected with driven wheel, and described driven wheel engages with bull gear (6).

8. the self-locking clamping of injection machine according to claim 2; it is characterized in that: described moving die plate (2) is provided with the displacement transducer moved forward and backward for detecting bull gear (6); during die sinking; displacement transducer detects that bull gear gets back to original position, then hydraulic control motor (10) quits work.