JP2011020370A - Mold clamping device for molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold clamping device capable of preventing a locking means from being damaged, and capable of engaging surely a half-nut with a half-nut engagement groove, even when a set position of the half-nut is not matched severely with that of the half-nut engagement groove. <P>SOLUTION: Full lengths L of the first and second half-nuts 277, 278 are formed to be shorter by about 1 mm than a space D between a locking means attaching face of a movable die plate 24 and an inner face of a front face 271c constituting a support member 271. In concretely saying, a holding plate 273 constituting the locking means 27, a screw shaft 274, a right screw nut body 275, a left screw nut body 276 and the first and second half-nuts 277, 278 are attached to the support member 271 via a sliding means 272, and the first and second half-nuts 277, 278 are displaced within a clearance provided between the locking means attaching face of the movable die plate 24 and the front face 271c of the support member 271. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mold clamping device provided in a molding machine such as an injection molding machine or a die casting machine, and more particularly, to a configuration of a tie bar lock means provided in a so-called two platen type mold clamping device.

  The two platen type mold clamping device has a fixed die plate with a fixed die, a movable die plate with a movable die, a tie bar bridged between the fixed die plate and the movable die plate, and a fixed die plate. Mold opening / closing means for driving the movable die plate in the mold opening / closing direction with respect to the die plate, locking means for integrally connecting the movable die plate and the tie bar at the mold closing position, and the fixed mold and the fixed mold via the tie bar And a mold clamping means for applying a required mold clamping force between them, and a member corresponding to a head stock provided in a three platen type mold clamping device can be omitted. The machine weight of the molding machine can be reduced and the installation area can be reduced.

  The locking means has a half nut attached to the movable die plate so as to be opened and closed, and the movable die plate and the tie bar are integrated by engaging the half nut with a half nut engaging groove formed in the tie bar. The movable die plate can be moved relative to the tie bar (fixed die plate) by releasing the engagement between the half nut engaging groove and the half nut.

  Conventionally, as a drive source of the lock means, one using a hydraulic device (for example, see Patent Document 1) and one using a pressure cylinder such as an air cylinder (for example, see Patent Document 2) are known. .

JP-A-10-258450 JP 60-212320 A

  However, equipment that uses a hydraulic device as the drive source for the locking means must be equipped with equipment such as a hydraulic tank, hydraulic pump, and hydraulic piping in the molding plant, which increases the size and complexity of the equipment. There is a problem that the cost becomes high. In addition, this type of locking means requires the sensors because the half nut cannot reach the lock position or unlock position of the tie bar unless the operating position of the half nut is detected using sensors. This is a component, and the equipment cost is expensive from this point. Further, this type of locking means has a problem that the inside of the molding factory is easily contaminated due to oil leakage from the hydraulic device.

  On the other hand, a device using a pressure cylinder such as an air cylinder as a drive source for the locking means can simplify the equipment compared to a device using a hydraulic device, and there is a risk that the molding factory may become dirty due to oil leakage. However, as in the case of using a hydraulic device, a sensor for detecting that the half nut has reached the locked position or unlocked position of the tie bar is required. There is a problem that it is difficult to reduce the cost.

  Such a problem can be solved by adopting a configuration in which an electric servo motor is used as a drive source of the lock means and the driving force of the electric servo motor is transmitted to the half nut via the ball screw mechanism. However, according to such a configuration, since the half nut is connected to the ball screw mechanism without loosening, unlike the case where a pressure cylinder such as an air cylinder is used as a driving source of the locking means, play is provided to the movement of the half nut. If the setting position of the half nut and the setting position of the half nut engaging groove formed on the tie bar do not exactly match, the engagement of these members cannot be performed smoothly, and the locking means It is expected that an excessive force is applied to cause a disadvantage that the locking means is broken.

  The present invention has been made in order to avoid such inconveniences, and the purpose thereof is, even if the setting position of the half nut engaging groove formed in the half nut and the tie bar does not exactly match, An object of the present invention is to provide a mold clamping device that can prevent breakage of locking means and can reliably engage a half nut and a half nut engaging groove.

  In order to solve the above problems, the present invention provides a fixed die plate to which a fixed mold is attached, a movable die plate to which a movable mold is attached, and a tie bar that is bridged between the fixed die plate and the movable die plate. A mold opening / closing means for driving the movable die plate in a mold opening / closing direction with respect to the fixed die plate, a lock means for integrally connecting the movable die plate and the tie bar at a mold closing position, and via the tie bar. In addition, in the mold clamping device of the molding machine including a mold clamping unit that applies a required mold clamping force between the fixed mold and the fixed mold, the lock unit is opposed to the other through the tie bar. The two half nuts arranged in the table, the electric servo motor for locking which is a driving source of the two half nuts, and the driving force of the electric servo motor for locking are A ball screw mechanism that transmits to the nuts and relatively drives the two half nuts in a direction approaching the tie bar or in a direction away from the tie bar, the two half nuts being in an axial direction of the tie bar It can be moved by a small amount to attach to the movable die plate.

  When an electric servo motor is used as a drive source for the half nut, unlike the case where a hydraulic device is used, various equipment and pipes serving as a hydraulic source can be omitted, so that the equipment cost of a molding factory can be reduced. In addition, it is impossible to cause oil leakage from the hydraulic device, so that the molding factory can be kept clean. Furthermore, since the operating position of the half nut can be known from the output signal from the encoder laid on the electric servo motor, sensors for detecting the operating position of the half nut are not required. Simplification and cost reduction can be achieved. In addition, if the half nut can be moved by a small amount in the axial direction of the tie bar, even if the setting position of the half nut and the setting position of the half nut engaging groove formed on the tie bar do not exactly match When the driving force of the electric servomotor for locking is received, the half nut can be automatically displaced in a direction that matches the half nut engaging groove, so that the engagement between the half nut and the half nut engaging groove Can be reliably performed, and an excessive force can be prevented from acting on the locking means, so that the locking means can be prevented from being broken.

  Further, in the mold clamping device of the molding machine having the above configuration, the present invention bridges a plurality of tie bars between the fixed die plate and the movable die plate, and corresponds to each of the plurality of tie bars. The lock means is arranged.

  According to such a configuration, since each tie bar is locked by a plurality of locking means, the locking force of the tie bar can be increased, and the clamping force can be applied uniformly to the fixed mold and the movable mold, such as a flash It is possible to mold a high-quality molded product without any defects.

  In the mold clamping device of the molding machine having the above-described configuration, the ball screw mechanism includes a right screw formed on one side and a left screw formed on the other side with a substantially central portion as a boundary, and the lock A screw shaft that is rotationally driven by the electric servomotor, a right screw nut that is formed integrally with one of the two half nuts and screwed to the right screw, and a second screw nut that is integral with the other half nut. And a left screw nut body screwed onto the left screw.

  According to such a configuration, a right screw and a left screw are formed on one screw shaft, and a right screw nut body and a left screw nut body are screwed into the right screw portion and the left screw portion of the screw shaft, respectively. Compared to the case where the right screw shaft and the left screw shaft formed separately are used, the configuration of the mold clamping device can be simplified and the cost can be reduced.

  According to the present invention, since the electric servo motor is used as the drive source of the half nut, the equipment can be simplified and the cost can be reduced as compared with the case where a pressure cylinder such as a hydraulic device or an air cylinder is used. The inside environment can also be kept good. In addition, since the half nut can be moved by a small amount in the axial direction of the tie bar, even if the setting position of the half nut and the setting position of the half nut engaging groove formed on the tie bar do not exactly match The half nut and the half nut engaging groove can be reliably engaged with each other, and an excessive force can be prevented from acting on the lock means, so that the lock means can be prevented from being broken.

It is a perspective view of an injection molding machine provided with a mold clamping device concerning an embodiment. It is principal part sectional drawing which shows the operation | movement of a half nut, and the meshing state of a half nut and a half nut engaging groove. It is principal part sectional drawing seen from the side of the mold clamping apparatus in a mold closed state. It is the front view seen from the lock means attachment surface side of a movable die plate. It is a front view of a locking means. It is a side view of a locking means. It is a top view of the mold clamping apparatus in a mold closed state. It is a top view of the mold clamping apparatus in a mold clamping state.

  Hereinafter, a mold clamping device of a molding machine according to an embodiment will be described by taking a mold clamping device of an injection molding machine as an example. As shown in FIG. 1, an injection molding machine provided with a mold clamping device according to the embodiment includes a mold clamping device 2 provided on a base frame 1, and an injection device 3 disposed opposite to the mold clamping device 2. The mold clamping device 2 and the controller 4 that controls the driving of the injection device 3 are mainly configured.

  The mold clamping device 2 includes a fixed die plate 22 to which the fixed mold 21 is attached, a movable die plate 24 to which the movable mold 23 is attached, and a total of four bridges between the fixed die plate 22 and the movable die plate 24. A tie bar 25, a mold opening / closing means 26 for driving the movable die plate 24 in the mold opening / closing direction with respect to the fixed die plate 22, and a movable die plate 24 and a tie bar 25 attached to the movable die plate 24, A locking means 27 for integrally connecting them, a clamping means 28 for applying a required clamping force between the fixed mold 21 and the movable mold 23 via the tie bar 25, a mold opening / closing means 26, a locking means. 27 and the controller 4 for controlling the driving of the mold clamping means 28.

  A desired cavity (not shown) is formed on the abutting surfaces of the fixed mold 21 and the movable mold 23, and the fixed mold 21 is not shown for guiding the molten resin injected from the injection device 3 into the cavity. The spool communicates.

  The fixed die plate 22 is fixed to the base frame 1 using bolts 221. On the other hand, the movable die plate 24 is slidably attached to the base frame 1 via the guide rail 241 and is movable in a direction approaching or separating from the fixed die plate 22. As is clear from FIG. 1, the fixed die plate 22 and the movable die plate 24 are formed in a substantially square front shape, and the tie bar 25 is penetrated through the tie bar through holes formed at the four corners. The fixed die plate 22 is provided with a nozzle insertion hole (not shown) for inserting the injection nozzle provided in the injection device 3 and bringing the tip of the injection nozzle into contact with the spool provided in the fixed mold 11.

  The tie bar 25 guides the movable die plate 24 toward or away from the fixed die plate 22 and drives the mold clamping means 28 between the fixed mold 21 and the movable mold 23 during mold clamping. A mold clamping force generated by this is applied, one end of which is fixed to the mold clamping means 28 and the other end is inserted into a tie bar insertion hole provided in the movable die plate 24. When the movable die plate 24 is moved to the mold closed position by the mold opening / closing means 26, the end of the tie bar 25 inserted into the tie bar insertion hole of the movable die plate 24 faces the lock means mounting surface side of the movable die plate 24. When the movable die plate 24 is moved to the mold open position by the mold opening / closing means 26, the length is formed so as not to drop out from the tie bar insertion hole of the movable die plate 24. As shown in FIGS. 2A to 2C, a plurality of rows of half nut engaging grooves 251 are formed at a constant pitch in the portion protruding in the direction.

  The mold opening / closing means 26 reciprocates the movable die plate 24 between a mold closed position where the abutting surfaces of the fixed mold 21 and the movable mold 23 are in contact with each other and a mold open position where the molded product is taken out. As shown in FIG. 3, a screw shaft 261 having one end fixed to a fixed die plate 22 and a mold opening / closing electric servomotor 262 with a nut body screwed into the screw shaft 261 are provided. Is done. The mold opening / closing electric servomotor 262 is a so-called built-in motor, and includes a casing 263, a cylindrical motor stator 264 fixed to the inner surface of the casing 263, and an outer periphery of the motor stator 264. A wound motor coil 265, a cylindrical motor rotor 266 disposed in the motor stator 264, a nut body 267 formed integrally with the motor rotor 266, and an outer surface of the motor rotor 266 are attached. The motor magnet 268 is configured. When the mold opening / closing electric servomotor 262 is rotated in one direction, the nut body 267 moves in one direction along the slope of the thread formed on the screw shaft 261, and for example, the movable die plate 24 moves in the mold closing direction. . When the mold opening / closing electric servomotor 262 is rotated in the other direction, the nut body 267 moves in the other direction along the slope of the thread formed on the screw shaft 261. For example, the movable die plate 24 is moved. Move in the mold opening direction.

  The lock means 27 is attached to the surface of the movable die plate 24 that does not face the fixed die plate 22 and is provided for each tie bar 25 that penetrates the movable die plate 24 as shown in FIG. As shown in FIGS. 5 and 6, the lock means 27 includes an upper plate 271 a, a lower plate 271 b, and a front plate 271 c, and a support member in which tips of the upper plate 271 a and the lower plate 271 b are fixed to the movable die plate 24. 271 and two holding plates 273 that are attached to the upper and lower surfaces of the support member 271 via the sliding means 272 and can move a little in the normal direction of the locking means mounting surface of the movable die plate 24, and these 2 One side of the holding plate 273 bridged at both ends, a total of two screw shafts 274, and a right screw nut body 275 and a left screw nut body screwed into the two screw shafts 274, respectively. 276, a first half nut 277 formed integrally with the right screw nut body 275, a second half nut 278 formed integrally with the left screw nut body 276, and an unillustrated requirement And a locking electric servomotor 279 that drives rotation of the screw shaft 274 via the power transmission mechanism. The screw shaft 274 is formed with a right-hand thread for screwing a right-hand screw nut body 275 on one side and a left-hand side for screwing a left-hand screw nut body 276 on the other side, with a substantially central portion as a boundary. A screw is formed. As shown in FIG. 5, the first and second half nuts 277, 278 are formed in a substantially semicircular front shape, and in the length direction of the inner surface thereof, as shown in FIG. A plurality of rows of engaging convex portions 277a and 278a that can be inserted into the half nut engaging groove 251 formed on the outer surface are formed at a constant pitch. As the lock electric servomotor 279, a built-in motor similar to the mold opening / closing electric servomotor 262 can be used.

  Since the locking means 27 of this example is configured as described above, when the electric servomotor 279 for locking is rotationally driven, the rotational force is transmitted to the screw shaft 274 via a power transmission mechanism (not shown), and the screw shaft 274 Is transmitted to the right screw nut body 275 and the left screw nut body 276, and the first and second half nuts 277, 278 move in a direction toward or away from each other. The moving directions of the first and second half nuts 277 and 278 are switched by rotating the electric servomotor 279 for locking forward or reverse. When the first and second half nuts 277 and 278 move toward each other and the engaging protrusions 277a and 278a are inserted to a predetermined position in the half nut engaging groove 251, the tie bar 25 is locked. When the first and second half nuts 277 and 278 are moved away from each other and the engaging projections 277a and 278a are completely separated from the half nut engaging groove 251, the tie bar 25 is unlocked. It becomes.

  Further, the total length L of the first and second half nuts 277 and 278 is the distance between the lock means mounting surface of the movable die plate 24 and the inner surface of the front plate 271c constituting the support member 271 as shown in FIG. It is formed slightly smaller than D, for example, about 1 mm. As described above, the holding plate 273, the screw shaft 274, the right screw nut body 275, the left screw nut body 276, and the first and second half nuts 277 and 278 constituting the lock means 27 are the sliding means 272. Since the first and second half nuts 277 and 278 are attached to the support member 271 via the support member 271, a clearance is provided between the lock means mounting surface of the movable die plate 24 and the front plate 271c of the support member 271. Thus, the first and second half nuts 277 and 278 can be freely displaced within the clearance range. Therefore, even when the engaging protrusions 277a, 278a and the half nut engaging groove 251 do not completely match, this play can be used to securely lock the tie bar 25 with the locking means 27 and the engaging protrusions. Excessive force can be prevented from acting on the portions 277a, 278a and the half nut engaging groove 251, and damage to the tie bar 25 and the lock member 27 can be prevented.

  As shown in FIG. 1, the mold clamping unit 28 includes a first mold clamping unit 28 a that applies a mold clamping force to the two tie bars 25 arranged on the upper side of the fixed die plate 22 and the movable die plate 24. A second mold clamping means 28b for applying a mold clamping force to the other two tie bars 25 arranged on the lower side is configured. According to this configuration, since the two mold clamping means 28a and 28b are used in parallel, the size of the mold clamping means per one can be reduced, and the installation area of the molding machine can be reduced. The first mold clamping means 28a applies a mold clamping force to the two tie bars 25 arranged on either the left or right side of the fixed die plate 22 and the movable die plate 24, so that the second mold clamping is performed. The means 28b may be configured to apply a clamping force to the two tie bars 25 arranged on the other side of the fixed die plate 22 and the movable die plate 24.

  As shown in FIGS. 7 and 8, the first and second mold clamping means 28a and 28b include a motor mounting member 281 to which one end of the tie bar 25 is fixed, and a mold clamping mounted to the motor mounting member 281. Electric servomotor 282, a substantially L-shaped B link 283 whose one end is pivotally coupled to motor mounting member 281 and one end is pivotally coupled to fixed die plate 22 and the other end A link 284 that is pin-coupled so that the side rotates relative to the other end side of the B link 283, a cross head 286 that receives the driving force of the mold clamping electric servo motor 282 via the ball screw mechanism 285, and one end Is coupled to the cross head 286 so as to be pivotable, and the C link 287 is coupled to the other end of the B link 283 so as to pivot relative to the other connecting portion. Consisting of. In the mold clamping means of this example, the toggle link mechanism is a link mechanism having a five-point pivot structure having an A link 284, a B link 283, and a C link 287. The gist of the present invention is as follows. Of course, other types of toggle link mechanisms can be used. As the mold clamping electric servo motor 282, a built-in motor similar to the mold opening / closing electric servo motor 262 can be used.

  As shown in FIG. 7, these mold clamping devices 28 a and 28 b are provided with a locking means 27 in a half nut engaging groove 251 formed in the tie bar 25 with the fixed mold 21 and the movable mold 23 closed. From the state in which the first and second half nuts 277 and 278 provided are locked (in FIG. 7, in order to facilitate understanding, between the fixed mold 21 and the movable mold 23, A slight gap is drawn.) When the mold clamping electric servo motor 282 is driven and the cross head 286 is moved to the fixed die plate 22 side via the ball screw mechanism 285, as shown in FIG. 284 and B link 283 extend in a straight line, the motor mounting member 281 moves backward toward the injection device 3 side, a tensile force acts on the tie bar 25, and the fixed mold 21 and the movable mold 23 are clamped. . Thereby, since a required cavity is formed between the fixed mold 21 and the movable mold 23, the injection of the molding material into the cavity by the injection device 3 becomes possible. From this state, when the mold clamping electric servo motor 282 is driven and the cross head 286 is moved to the motor mounting member 281 side via the ball screw mechanism 285, as shown in FIG. 7, the A link 284 and the B link 283 are used. Are folded, the motor mounting member 281 moves forward to the fixed die plate 22 side, and the fixed mold 21 and the movable mold 23 are opened.

  As shown in FIG. 1, the injection device 3 includes a weighing electric servomotor 301 and two injection electric servomotors 302 and 303, and the resultant force of the two injection electric servomotors 302 and 303 is heated. This is transmitted to a screw (not shown) that is housed in the cylinder 304 so as to be rotatable and capable of moving forward and backward, and the molten resin is injected into a cavity formed between the fixed mold 21 and the movable mold 23. Note that a built-in motor similar to the mold opening / closing electric servomotor 262 can also be used as the metering electric servomotor 301 and the injection electric servomotors 302 and 303. The configuration of the injection device 3 is not the gist of the present invention, and is a matter that belongs to the public knowledge, and thus further explanation is omitted.

  The controller 4 includes two mold opening / closing electric servo motors 262, four locking electric servo motors 279, two mold clamping electric servo motors 282, an injection electric servo motor 301, and injection electric servo motors 302 and 303. The control signals l to v of the electric servomotors are generated based on the position signals a to k output from the encoders incorporated in the encoder, and the driving of the electric servomotors is stopped via a motor driver circuit (not shown). To control.

  Hereinafter, the operation control of the injection molding machine performed by the controller 4 will be described.

  When the mold is attached (during replacement), the movable die plate 24 is moved to the mold opening position by driving the mold opening / closing electric servomotor 262, and the lock means 27 is driven by driving the locking electric servomotor 279. The first and second half nuts 277 and 278 are moved to the unlocking position, and the mold clamping means 28 drives the mold clamping electric servo motor 282 so that the motor mounting member 281 is farthest from the fixed die plate 22. Moved to position. In this state, the fixed mold 21 and the movable mold 23 are attached to the fixed die plate 22 and the movable die plate 24, respectively.

  Thereafter, the controller 4 drives the mold opening / closing electric servo motor 262 to move the movable die plate 24 to the fixed die plate 22 side to the mold closed position of the fixed mold 21 and the movable mold 23. The mold closing position of the movable die plate 24 is stored in the controller 4.

  When the movable die plate 24 is moved to the mold closing position, the tip portion of the tie bar 25 passes through the tie bar through hole provided in the movable die plate 24 and protrudes to the lock member mounting surface side of the movable die plate 24. . The amount of protrusion of the tie bar 25 from the movable die plate 24 varies depending on the die height of the fixed mold 21 and the movable mold 23, and as shown in FIG. 2 (c), the half nut engaging groove 251 formed in the tie bar 25 is provided. The formation position and the formation positions of the engaging projections 277 a and 278 a formed on the first and second half nuts 277 and 278 are shifted in the axial direction of the tie bar 25. The shift amount is a maximum of one pitch of the formation pitch p of the half nut engagement groove 251 and is a remainder value of a quotient obtained by dividing the die height (known) by the formation pitch (known) of the half nut engagement groove. . The driving amount of the mold clamping electric servo motor 282 for moving the tie bar 25 by the amount of movement corresponding to the remainder is easily obtained from the lengths of the A link 284 and the B link 283 constituting the toggle link mechanism. be able to. These calculations are performed by the controller 4. The controller 4 drives the mold clamping electric servomotor 282 based on the calculation result, and moves the tie bar 25 by a predetermined amount via the toggle link mechanism. Thereby, as shown in FIG. 2B, the formation position of the half nut engagement groove 251 and the formation position of the engagement protrusions 277a and 278a formed in the first and second half nuts 277 and 278 Can be matched.

  Next, the controller 4 drives the electric servomotor 279 for locking and moves the first and second half nuts 277 and 278 in a direction approaching each other. When the formation position of the half nut engagement groove 251 and the formation position of the engagement protrusions 277a and 278a are completely matched, the engagement protrusions 277a and 278a are approximately the frictional force acting between the tie bars 25. It enters into the half nut engaging groove 251 with the resistance force of. When the output of the encoder provided in the lock electric servomotor 279 reaches a predetermined tie bar lock position, the lock electric servomotor 279 is stopped. As a result, the tie bar 25 is locked to the movable die plate 24.

  If the formation position of the half nut engagement groove 251 and the formation position of the engagement protrusions 277a and 278a do not completely match, the direction in which the first and second half nuts 277 and 278 approach each other. When moved to, the engaging convex portions 277a and 278a abut against the half nut engaging groove 251. However, the first and second half nuts 277 and 278 can be freely displaced within a clearance range provided between the movable die plate 24 and the front plate 271c of the support member 271. When it collides with the half nut engaging groove 251, the force is displaced in a direction to avoid the collision, and insertion into the half nut engaging groove 251 becomes possible. Therefore, the tie bar 25 can be reliably locked, an excessive force can be prevented from acting on the tie bar 25 and the lock means 27, and vibration and noise can be reduced and durability can be improved.

  After the tie bar 25 is locked to the movable die plate 24 by the locking means 27, the controller 4 drives the mold clamping electric servo motor 282 until the A link 284 and the B link 283 extend in a straight line. Move forward. Thereby, a tensile force acts on the tie bar 25, and the fixed mold 21 and the movable mold 23 are clamped.

  After mold clamping, the controller 4 drives the injection electric servo motors 302 and 303 to inject a predetermined amount of molten resin into the mold cavity. After injection, the process returns to the original position through the reverse process.

  The mold clamping device of the molding machine according to the above embodiment uses the mold opening / closing electric servomotor 262 and the mold clamping electric servomotor 282 to use the half nut engaging groove 251 and the first and second half nuts 277 and 278. Therefore, it is not necessary to provide special means used only for adjusting these meshing positions, and the mold clamping device 2 and thus the molding machine can be reduced in size, simplified and reduced in cost. Can be planned. In addition, since all the electric servo motors are used as the drive sources for each part of the apparatus, the molding machine can be fully motorized. From this point, the mold clamping device 2 and thus the molding machine can be reduced in size, simplified and reduced in cost. In addition, as in the case where a hydraulic actuator is used instead of the electric servo motor, contamination in the molding factory due to oil leakage can be prevented, and the working environment in the molding factory can be improved.

  In the above-described embodiment, the mold clamping device of the injection molding machine has been described as an example, but the present invention can also be applied to a die clamping machine.

  In the above embodiment, the electric servo motor is used as the drive source for the mold opening / closing means 26, the lock means 27, the mold clamping means 28, and the injection apparatus 3. However, as the drive source for the lock means 27 and the injection apparatus 3, A hydraulic actuator or an air actuator can also be used.

  Further, in the above-described embodiment, built-in motors are used as the mold opening / closing electric servomotor 262, the locking electric servomotor 279, the mold clamping electric servomotor 282, and the weighing / injection electric servomotors 301, 302, and 303. However, it is of course possible to use other types of motors.

  The present invention can be used for a mold clamping device of an injection molding machine or a die casting machine.

DESCRIPTION OF SYMBOLS 1 Base frame 2 Clamping device 21 Fixed mold 22 Fixed die plate 23 Movable mold 24 Movable die plate 25 Tie bar 251 Half nut engaging groove 26 Mold opening / closing means 261 Screw shaft 262 Mold opening / closing electric servo motor 263 Casing 264 Motor fixing Child 265 Motor coil 266 Motor rotor 267 Nut body 268 Motor magnet 27 Locking means 271 Support member 272 Sliding means 273 Holding plate 274 Screw shaft 275 Right screw nut body 276 Left screw nut body 277 First half nut 278 First 2 half nuts 279 Electric servo motor for locking 28 Mold clamping means 28a First mold clamping means 28b Second mold clamping means 281 Motor mounting member 282 Mold clamping electric servo motor 283 B link 284 A link 285 Ball screw mechanism 2 86 Cross head 287 C link 3 Injection device 301 Electric servo motor for weighing 302, 303 Electric servo motor for injection 4 Controller

Claims (3)

A fixed die plate with a fixed mold attached, a movable die plate with a movable mold attached, a tie bar bridged between the fixed die plate and the movable die plate, and the movable with respect to the fixed die plate Mold opening / closing means for driving the die plate in the mold opening / closing direction, locking means for integrally connecting the movable die plate and the tie bar at the mold closing position, and the fixed mold and the fixed mold via the tie bar A mold clamping device of a molding machine provided with a mold clamping means for applying a required mold clamping force between
The locking means includes two half nuts arranged opposite to each other via the tie bar, an electric servo motor for locking that is a driving source of the two half nuts, and a driving force of the electric servo motor for locking. It is transmitted to two half nuts, and consists of a ball screw mechanism that relatively drives the two half nuts in a direction approaching the tie bar or in a direction away from the tie bar,
The mold clamping device for a molding machine, wherein the two half nuts are attached to the movable die plate so as to be slightly movable in the axial direction of the tie bar.   The plurality of tie bars are bridged between the fixed die plate and the movable die plate, and the locking means is arranged corresponding to each of the plurality of tie bars. Mold clamping device for molding machine.   The ball screw mechanism has a right-hand thread formed on one side and a left-hand thread formed on the other side with a substantially central portion as a boundary, a screw shaft that is rotated by the electric servomotor for locking, and the two half A right screw nut body formed integrally with one of the nuts and screwed to the right screw, and a left screw nut body formed integrally with the other of the two half nuts and screwed to the left screw The mold clamping device for a molding machine according to claim 1, wherein the mold clamping device is configured as follows.

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