KR20090092494A - Molds Clamping Apparatus of Injection Molding Machine - Google Patents

Abstract

A mold clamping apparatus of an injection molding machine is provided to prevent loosening of a lock nut as the lock nut and a housing are locked at a protrusion and a groove when a guide bar moves backward. A mold clamping apparatus of an injection molding machine comprises a fixed template, a movable template(20), a guide bar(30), a transfer cylinder, and a lock nut(50). The fixed template has a first molding unit. The movable template has a second molding unit. The guide bar provides a clamping force by hydraulic pressure acting on a mold cylinder. The transfer cylinder delivers the movable template back and forth. The lock nut moves advances or retracts in the radial direction of the guide bar by a nut cylinder(70). A protrusion and a groove are formed in the back end surface of the lock nut and the rear inner surface of a housing(60). When the guide bar retracts, the movement of the lock unit is blocked by the protrusion and the groove and the force retracting the guide bar is transferred to the movable template.

Description

Molding device of injection molding machine {Molds Clamping Apparatus of Injection Molding Machine}

The present invention relates to a mold clamping apparatus of an injection molding machine, and more particularly, a mold of an injection molding machine capable of implementing high-speed precision operation by distinguishing between a high-pressure mold opening operation and a transfer operation of a movable mold for ejecting a molded product. Relates to a device.

The molding device of the injection molding machine is a device that closes the mold with a strong clamping force so that the mold does not open during injection, and opens the mold and removes the molded product when the injected resin solidifies. And a transfer cylinder for moving the movable die.

Specifically, as shown in FIG. 1, the mold clamping device 2 includes a stationary mold plate 10 having a first mold portion 11, a movable mold plate 20 having a second mold portion 21, A guide bar 30 for guiding movement of the movable die 20 and providing a clamping force by hydraulic pressure acting on the die cylinder 31, and a transfer cylinder 40 for forwarding and moving the movable die 20 back and forth. And a locking nut 50 mounted to the movable die 20 to couple to the guide bar 30 to lock the movable die 20 at the time of mating.

Here, the guide bar 30 guides the linear motion of the movable plate 20, the guide bar 30 of the hydraulic system 32 to enter and exit the mold cylinder 31 installed on the fixed plate 10 Move forward and backward by operating hydraulic pressure.

In the conventional locking device for locking the movable plate 20 through the lock nut 50, the lock nut 50, the housing 60 is fixed to the movable plate 20, as shown in detail in FIG. ) Is installed inside. The lock nut 50 is moved forward / backward in the radial direction of the guide bar 30 by the nut cylinder 70, so that the teeth 35 formed in the guide bar 30 and the teeth 55 formed in the lock nut 50. Is locked / unlocked by

Such a mold clamping device joins or molds the first and second mold parts 11 and 21 provided in the stationary mold plate 10 and the movable mold plate 20. Conventionally, both the mold and the mold opening are made by moving the movable die 20 back and forth by the transfer cylinder 40. After molding, as shown in FIG. 2, the nut cylinder 70 is operated to lock the nut 50. Advance to engage the teeth 55 of the lock nut 50 and the teeth 35 of the guide bar 30. The teeth 35 of the guide bar 30 and the teeth 55 of the lock nut 50 have vertical surfaces 35a and 55a and inclined surfaces 35b and 55b. After fastening, one side of the vertical surfaces 35a and 55a is provided. The load Fc can be transmitted only in the direction. When the lock nut 50 and the guide bar 30 are fastened as described above, the mold cylinder 31 receives the high pressure hydraulic oil to pull the guide bar 30, and accordingly the teeth 35 of the guide bar 30. The vertical surface 35a of the puller pulls the vertical surface 55a of the teeth 55 of the lock nut 50, and the first and second mold parts 11 and 21 are strongly joined by this force, and the high-pressure molten resin is introduced into the mold. It will not open when is injected. When molten resin is injected into the mold and the molded article is molded, the first mold part 11 and the second mold part 21 are joined by the molded part. Therefore, in order to open the mold, a load equal to or greater than this joining force must be applied. Is called a high pressure dog.

In the case of such high pressure type opening, the locking nut 50 and the guide bar 30 are first unlocked and then carried out through the transfer cylinder 40. Therefore, the conventional injection molding machine is the transfer cylinder 40 performs both the high-speed forward and backward operation and the high-pressure type opening operation. It is advantageous that the diameter of the transfer cylinder 40 is small because only the weight of the movable die 20 can be accommodated for the high-speed forward and backward operations, but in order to perform the high pressure mold opening operation, the bonding force by the molding in addition to the weight of the movable die 20 is performed. In order to generate large mold opening force, the diameter of the transfer cylinder 40 needs to be large, so that a contradiction arises. That is, if the diameter of the transfer cylinder 40 is small, it is advantageous for high-speed forward and backward, but the high-pressure type dog is disadvantageous. If the diameter of the transfer cylinder 40 is large, it is advantageous for the high-pressure dog dog, but the operating flow rate increases and the position of the movable die 20 is increased. Since the control precision is poor, it is disadvantageous for the high speed forward and backward operation, and the price of the transfer cylinder 40 increases.

While repeating the research to solve such a conventional problem, the high pressure mold opening is performed by the guide bar 30 and the mold cylinder 31 without the transfer cylinder 40, and after the high pressure mold opening the transfer cylinder 40 By fully opening the movable die 20 by means of the mold cylinder 31, which has a large force for the original mold, the mold is opened, so that the high pressure mold is easy to open and the diameter of the transfer cylinder 40 is also small. I realized that it is advantageous for high speed precision operation.

However, in order to open the high pressure, the force should be transmitted to the movable plate 20 by the guide bar 30, and in order to do so, the lock nut 50 should be transmitted as it is fastened to the guide bar 30. As shown in FIG. 2, when the force acts in the opposite direction (ie, the mold opening direction) while the lock nut 50 is engaged, the force is transferred to the inclined surfaces 35b and 55b of the teeth 35 and 55 to lock the nut. Since the force of the nut 50 is induced radially outward, that is, in the direction of releasing the fastening of the lock nut 50, it is faced with an additional problem that it is difficult to maintain the fastened state.

In accordance with the above problem, the present invention by performing the high-pressure type opening operation of the movable plate by the guide bar to be performed by distinguishing the high-pressure opening operation and the transfer operation, by preventing the locking nut 50 is not released when the high pressure opening, The purpose is to obtain a high-pressure type opening operation and high speed precision operation.

An object of the present invention described above is a guide plate for guiding movement of the movable mold plate and providing a clamping force by hydraulic pressure acting on the mold cylinder of the fixed mold plate with a fixed mold plate having a first mold portion and a second mold portion. A transfer cylinder for transferring the movable plate back and forth and the housing fixed to the movable plate to move forward / backward in the radial direction of the guide bar by a nut cylinder and engage with the teeth formed on the guide bar. And a locking nut having a locking nut, and a locking jaw protrudes from the rear end surface of the locking nut, and a locking groove is formed on the rear inner surface of the housing to restrict the movement of the locking jaw of the locking nut in a release direction. When the guide bar is retracted by supplying hydraulic pressure to the mold cylinder after the solidification, the locking nut is pushed backward so that the locking jaw is closed. As the movement of the guide bar is retracted by the locking groove of the housing, the force for retracting the guide bar is transmitted to the housing through the tooth, the locking jaw and the locking groove, and the force transmitted to the housing is transferred to the movable plate. It is achieved by providing a mold clamping device of an injection molding machine, characterized in that the high-pressure mold opening by the guide bar is delivered.

According to the clamping apparatus of the injection molding machine of the present invention, when the guide bar is retracted, the locking nut and the housing are caught by the locking jaw and the locking groove to prevent the radial movement of the lock nut, that is, locking of the lock nut is prevented from being released. High pressure type opening is possible. Therefore, the high pressure mold opening can be realized by a mold cylinder having a large force for the original mold, and the transfer of the movable mold plate can be realized by the transfer cylinder.

Therefore, according to the present invention, it is easier to open the high-pressure mold, and a smaller diameter of the transfer cylinder can be used, so that the position control of the high speed forward and backward operation of the movable die can be more precisely realized.

1 is a schematic view showing a clamping apparatus of a conventional injection molding machine.

FIG. 2 is an enlarged view illustrating main parts illustrating a state in which the lock nut of the clamping device illustrated in FIG. 1 is locked and a clamping force is applied to the guide bar.

3 is a view illustrating a state in which the guide bar is pushed in the mold opening direction in FIG. 2.

4 is an enlarged view illustrating main parts of the mold clamping apparatus according to the present invention.

5 is a view illustrating a state in which the lock nut is locked in FIG. 4 and a clamping force is applied to the guide bar.

6 is a view showing a state at the time of high pressure mold opening in FIG.

7 is a view showing a state when releasing the lock nut in FIG.

<Description of Symbols for Major Parts of Drawings>

2: Clamping Device 10: Fixed Plate

11: first mold part 20: movable mold

21: second mold part 30: guide bar

31: shaped cylinder 32: hydraulic system

35, 55: tooth 35a, 55a: vertical plane

35b, 55b: inclined plane 40: transfer cylinder

50: lock nut 60: housing

70: nut cylinder 80a: locking jaw

80b: locking groove 81a, 81b: inclined surface

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is an enlarged view illustrating main parts of the injection molding machine according to the present invention. The same parts as in the above-described conventional configuration will be described with the same reference numerals. Reference numerals not shown in FIG. 4 refer to FIG. 1.

As shown in FIG. 4, the lock nut 50 and the guide bar 30 are engaged with each other by teeth 55 and 35, and a locking jaw is provided at the rear end surface 50a of the lock nut 50. 80a is formed to protrude, and a locking groove 80b is formed on the rear inner surface 60a of the housing 60 to restrict the movement of the locking jaw 80a of the lock nut 50 in the release direction. Here, the term "rear" refers to a direction in which the movable die 20 retreats, that is, a direction in which the movable die 20 is opened (left direction in FIG. 4).

Therefore, when molding is completed by molding and injection of molten resin, and the guide bar 30 is retracted, the inclined surface 35b of the teeth 35 of the guide bar 30 becomes the teeth 55 of the lock nut 50. The lock nut 50 is finely moved radially outward at the same time as the lock nut 50 is retracted by pushing the inclined surface 55b, and at the same time, the locking jaw 80a of the lock nut 50 is a locking groove of the housing 60. The lock nut 50 is caught by 80b) so that it cannot be opened radially outward of the guide bar 30. When the radial movement of the lock nut 50 is prevented by the housing 60 as described above, the force for retracting the guide bar 30 is transmitted to the housing 60 through the lock nut 50, and the housing 60. Is fixed to the movable die 20, the movable die 20 is retracted to form a high pressure die.

On the other hand, it is preferable that the engaging jaw 80a of the lock nut 50 and the engaging groove 80b of the housing 60 are inclined surfaces 81a and 81b. If the engaging surface of the engaging jaw (80a) and the engaging groove (80b) is made of the inclined surfaces (81a, 81b), after the high-pressure type release of the lock nut 50 (retraction to the radially outer side of the guide bar 30) ) Smooth operation.

Such operation of the present invention will be described in more detail with reference to FIGS. 4 to 7. See FIG. 1 in parallel.

As shown in FIG. 4, when the movable die 20 is retracted by the transfer cylinder 40, the first and second mold parts 11 and 21 are opened. Subsequently, the transfer cylinder 40 operates in the opposite direction (right side in the drawing) so that the movable die 20 performs a high speed forward operation toward the stationary die 10. At this time, the guide bar 30 guides the transfer of the movable die 20. When the movable die 20 is advanced to close the first mold part 11 and the second mold part 21, the nut cylinder 70 is operated to move the lock nut 50 toward the guide bar 30.

Then, as shown in FIG. 5, the teeth 55 of the lock nut 50 are engaged with the teeth 35 of the guide bar 30. In this state, the mold cylinder 31 is supplied with a high-pressure hydraulic fluid to pull the guide bar 30 to pull the movable mold plate 20 in close contact with the fixed mold plate 10. The first and second mold parts 11 and 21 are strongly coupled to each other by a force that pulls the movable die 20 and closely adheres to the fixed die 10, that is, the clamping force (molding force) Fc. Even if molten resin of is injected, it does not open.

Subsequently, molten resin is injected into the spout 11a (refer FIG. 1) of the stationary plate 10 through a nozzle, and a product is shape | molded. When molten resin is injected into the first and second mold parts 11 and 21 and the molded product is molded, the first mold part 11 and the second mold part 21 are joined by the molding, so that the mold is opened. Apply more load than this joint force. That is, high pressure type openings should be made.

In the case of high-pressure type startup, the locking nut 50 and the guide bar 30 are first released, and then the movable die 20 is moved through the transfer cylinder 10. However, in the present invention, the high pressure mold opening is performed through the guide bar 30 and the mold cylinder 31, not by the transfer cylinder 10. As shown in FIG. 1, one side of the guide bar 30 is connected to a mold cylinder 31, which is originally large to provide sufficient adhesion of the first and second mold parts 11 and 21. It consists of a dose. By the way, in the head portion of the guide bar 30 in the mold cylinder 31, when the guide bar 30 is pulled (i.e., molded), the surface to receive hydraulic pressure (i.e., the left side of the head in the drawing) is guided. The hydraulic pressure is applied only to the cross-sectional area excluding the diameter of the bar 30, but the surface subjected to the hydraulic pressure when pushing the guide bar 30 (that is, the cross-sectional area of the right side of the head in the drawing) receives the hydraulic pressure to its entire cross-section. By the way, since the mold cylinder 31 is originally made with a large capacity so as to provide sufficient molding force, it is possible to sufficiently perform the high pressure mold opening even with the force of the size acting at the time of molding, but the cross-sectional area subjected to hydraulic pressure at the time of mold opening is compared. Of course, the larger opening force than the opening force makes the opening easier.

6 illustrates a case in which the high pressure mold opening force is applied by reversing the guide bar 30. At this time, the teeth 55 of the lock nut 50 and the teeth 35 of the guide bar 30 are coupled back by a predetermined distance so that the lock nut 50 contacts the rear inner surface of the housing 60. Since the housing 60 has a state in which the first mold portion 11 of the movable mold plate 20 is joined to the second mold portion 21 of the stationary mold plate 10 by a molded article, the bonding force and the movable mold plate 20 are used. The movement is limited by the weight of). From the time when the lock nut 50 contacts the housing 60, the mold opening force, that is, the force for reversing the guide bar 30, is transmitted to the lock nut 50. At this time, since the lock nuts 50 and the teeth 35 and 55 of the guide bar 30 are in contact with the inclined surfaces 35b and 55b, the lock nuts 50 are pushed radially outward by the inclined surfaces 35b and 55b. There is a falling component. Conventional lock nut (50) could not maintain the fastening state because it does not support this force because it opens radially outward, the locking nut (50) and the housing (60) according to the present invention is the locking jaw (80a) and Since the movement in the radial direction is blocked by the locking groove (80b), the lock nut 50 is maintained in the state fastened to the guide bar (30). Therefore, the force pushing the guide bar 30 is transmitted from the lock nut 50 to the housing 60 by the locking jaw 80a and the locking groove 80b, and the housing 60 is fixed to the movable plate 20. As a result, the movable die 20 is pushed in the end, and this force, that is, the joining force due to the molded product is overcome by this force, that is, the mold opening force Fo, and the movable die 20 is opened at a high pressure.

7 is a case of releasing the fastening of the lock nut 50 after the high-pressure type opening process. When the first and second mold parts 11 and 21 are opened by the high pressure mold opening, the movable die 20 and the housing 60 attached thereto are free to move forward and backward. Therefore, the housing 60 is no longer able to resist movement of the lock nut 50. At this time, when the lock nut 50 is moved radially outward by operating the nut cylinder 70, the inclined surfaces 81a and 81b of the locking jaw 80a and the locking groove 80b are slid by the force of the nut cylinder 70. Is released.

After the high-pressure type opening is performed by the high-speed backward operation to reverse the movable die 20 to the initial state through the transfer cylinder 40 to return to the initial state as shown in Figure 4 and complete the operation. Since the transfer cylinder 40 can only handle the transfer of the movable die 20, not the high pressure die, the diameter can be reduced, so that the position control of the high speed forward and backward operation of the movable die can be more precisely implemented at a lower cost. Can be.

Claims (2)

A movable mold plate 20 having a first mold part 11 and a fixed mold plate 10 and a second mold part 21; A guide bar 30 which guides the movement of the movable plate 20 and provides a clamp force by hydraulic pressure acting on the mold cylinder 31 of the stationary plate 10; A transfer cylinder 40 for forwarding and moving the movable die 20; It is installed inside the housing 60 fixed to the movable die 20, and forward / backward in the radial direction of the guide bar 30 by a nut cylinder 70, the teeth formed in the guide bar (30 A lock nut 50 having teeth 55 engaged with 35; A locking jaw 80a protrudes from the rear end surface 50a of the lock nut 50. A locking groove 80b is formed in the rear inner surface 60a of the housing 60 to restrict the movement of the locking jaw 80a of the locking nut 50 in the release direction. When the guide bar 30 is retracted by supplying hydraulic pressure to the mold cylinder 31 after the molding is solidified, the lock nut 50 is pushed backward so that the locking jaw 80a is caught by the housing 60. As the movement to the radially outer side is stopped by the groove 80b, the force for retracting the guide bar 30 is transmitted through the teeth 35 and 55, the locking jaw 80a and the locking groove 80b. The clamping device of the injection molding machine, characterized in that the force transmitted to the housing (60), the force transmitted to the housing (60) is transmitted to the movable die (20) to form a high pressure mold opening by the guide bar (30). The method of claim 1, The locking jaw (80a) and the locking groove (80b) is a clamping device of the injection molding machine, characterized in that the engagement with each other by the inclined surface (81a, 81b).