JP4790566B2 - Clamping device - Google Patents

Description

  The present invention relates to a mold clamping device.

  2. Description of the Related Art Conventionally, in an injection molding machine, resin is injected from an injection nozzle of an injection device, filled into a cavity space between a fixed mold and a movable mold, and solidified to obtain a molded product. ing. A mold clamping device is provided for moving the movable mold relative to the fixed mold to perform mold closing, mold clamping, and mold opening.

  The mold clamping device includes a hydraulic mold clamping device that is driven by supplying oil to a hydraulic cylinder, and an electric mold clamping device that is driven by an electric motor. It is widely used because it has high controllability, does not pollute the surroundings, and has high energy efficiency. In this case, by driving the electric motor, the ball screw is rotated to generate a thrust, and the thrust is expanded by a toggle mechanism to generate a large mold clamping force.

  However, since the electric mold clamping device having the above-described configuration uses a toggle mechanism, it is difficult to change the mold clamping force due to the characteristics of the toggle mechanism, and the responsiveness and stability are improved. The mold clamping force cannot be controlled during molding. Therefore, a mold clamping device is provided in which the thrust generated by the ball screw can be directly used as a mold clamping force. In this case, since the torque of the electric motor and the mold clamping force are proportional, the mold clamping force can be controlled during molding.

  However, in the conventional mold clamping device, the load resistance of the ball screw is low and a large mold clamping force cannot be generated, and the mold clamping force fluctuates due to torque ripple generated in the electric motor. In addition, in order to generate the mold clamping force, it is necessary to constantly supply current to the motor, and the power consumption and heat generation amount of the motor increase. Therefore, it is necessary to increase the rated output of the motor by that amount. The cost of the device becomes high.

Therefore, a mold clamping device using a linear motor for the mold opening / closing operation and utilizing the attractive force of an electromagnet for the mold clamping operation is conceivable (for example, Patent Document 1).
WO05 / 090052 pamphlet

  However, when an electromagnet is used for mold clamping, it is necessary to generate a large attractive force in order to generate a desired mold clamping force. Therefore, it is necessary to increase the magnetomotive force (current and the number of coil windings) or increase the adsorption area by the electromagnet (the area of the opposing surface of the rear platen 13 and the adsorption plate 22 in Patent Document 1). An increase in magnetomotive force has a problem of increasing the amount of heat generation, and an increase in adsorption area has a problem of increasing the size of the apparatus. Furthermore, if the supply current is increased to increase the magnetomotive force, there is a problem that the running cost is increased.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a mold clamping device that can efficiently generate an attractive force by an electromagnet.

  In order to solve the above problems, the present invention provides a mold clamping device that has a coil holding member that holds a coil constituting an electromagnet and generates a clamping force by the electromagnet, and includes at least one of the coil holding members. The part is formed of a grain-oriented electrical steel sheet, and the grain-oriented electrical steel sheet is arranged in a direction in which the magnetic resistance decreases with respect to the direction in which the magnetic flux by the electromagnet passes.

  Moreover, this invention has the adsorption | suction member which forms the surface where the said coil is hold | maintained in the said coil holding member, and an opposing surface, The said coil holding member opposes the surface where the said coil is held, and the said adsorption member The directional electromagnetic steel sheet moves relative to the attracting member by the attracting force based on the electromagnet generated between the coil holding member and the coil holding member in the direction in which the magnetic resistance decreases. It arrange | positions on the opposite side to the said adsorption | suction member on both sides of the said coil so that it may orthogonally cross with respect to this direction.

  Moreover, this invention has the adsorption | suction member which forms the surface where the said coil is hold | maintained in the said coil holding member, and an opposing surface, The said coil holding member opposes the surface where the said coil is held, and the said adsorption member The directional electromagnetic steel sheet moves relative to the attracting member by the attracting force based on the electromagnet generated between the coil holding member and the coil holding member in the direction in which the magnetic resistance decreases. It is arrange | positioned in the location which faces the said opposing surface of the said adsorption member so that it may become the direction of this.

  According to the present invention, at least a part of the attracting member is formed of a directional electromagnetic steel plate, and the directional electromagnetic steel plate in the attracting member has a low magnetic resistance with respect to a direction in which the magnetic flux by the electromagnet passes. It is arranged in the direction.

  Further, the present invention provides the grain-oriented electrical steel sheet in the attracting member at a location facing the coil such that the direction in which the magnetic resistance is reduced is substantially orthogonal to the direction of relative movement of the coil holding member. It is characterized by being arranged.

  Further, in the present invention, the grain-oriented electrical steel sheet in the attracting member is disposed at a location that does not face the coil so that the direction in which the magnetic resistance decreases is a direction of relative movement of the coil holding member. It is characterized by that.

  In order to solve the above-described problem, the present invention provides a mold clamping device that generates a mold clamping force with an electromagnet, a coil holding member that holds a coil that constitutes the electromagnet, and the coil in the coil holding member. It has an adsorption member that forms a surface to be held and an opposing surface, and at least a part of the adsorption member is formed of a directional electromagnetic steel plate, and the directional electromagnetic steel plate is in a direction in which a magnetic flux by the electromagnet passes. Thus, the magnetic resistance is arranged in such a direction as to decrease.

  In the present invention, the coil holding member moves relative to the attracting member by an attracting force based on the electromagnet generated between a surface on which the coil is held and the facing surface of the attracting member. The directional electrical steel sheet is disposed at a position facing the coil such that a direction in which the magnetic resistance is reduced is substantially orthogonal to a direction of relative movement of the coil holding member. .

  In the present invention, the coil holding member moves relative to the attracting member by an attracting force based on the electromagnet generated between a surface on which the coil is held and the facing surface of the attracting member. Then, the grain-oriented electrical steel sheet is arranged at a location not facing the coil such that the direction in which the magnetic resistance is reduced is the direction of relative movement of the coil holding member.

  ADVANTAGE OF THE INVENTION According to this invention, the mold clamping apparatus which can generate | occur | produce the adsorption | suction force by an electromagnet efficiently can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, for the mold clamping device, the moving direction of the movable platen when closing the mold is the front, the moving direction of the movable platen when opening the mold is the rear, and the injection device is the injection The description will be made assuming that the moving direction of the screw when performing the measurement is the front and the moving direction of the screw when performing the measurement is the rear.

  FIG. 1 is a view showing a state of a mold apparatus and a mold clamping apparatus when the mold is closed in the embodiment of the present invention, and FIG. 2 is a state when the mold apparatus and the mold clamping apparatus are opened in the embodiment of the present invention. FIG.

  In the figure, 10 is a mold clamping device, Fr is a frame of an injection molding machine, Gd is laid on the frame Fr to form a rail, and supports the mold clamping device 10 as a first guide member for guiding it. The two guides (in the figure, only one of the two guides Gd is shown) 11 is placed on the guide Gd and fixed to the frame Fr and the guide Gd. A fixed platen as a first fixing member, and a rear platen 13 as a second fixing member is disposed at a predetermined distance from the fixed platen 11 and opposed to the fixed platen 11, and the fixed platen A tie bar 14 (only two of the four tie bars 14 are shown in the figure) is laid between 11 and the rear platen 13 as four connecting members. The rear platen 13 is placed on the guide Gd so that it can move slightly with respect to the guide Gd as the tie bar 14 expands and contracts.

  In the present embodiment, the fixed platen 11 is fixed to the frame Fr and the guide Gd, and the rear platen 13 can move slightly with respect to the guide Gd. The fixed platen 11 can be moved slightly with respect to the guide Gd by being fixed with respect to the Fr and the guide Gd.

  A movable platen 12 as a first movable member is disposed along the tie bar 14 so as to face the fixed platen 11 so as to be movable back and forth in the mold opening / closing direction. For this purpose, a guide hole (not shown) for penetrating the tie bar 14 is formed at a position corresponding to the tie bar 14 in the movable platen 12.

  A first screw portion (not shown) is formed at the front end portion of the tie bar 14, and the tie bar 14 is fixed to the fixed platen 11 by screwing the first screw portion and the nut n1. Further, a guide post 21 as a second guide member having an outer diameter smaller than that of the tie bar 14 is protruded rearward from the rear end surface of the rear platen 13 at a predetermined portion at the rear of each tie bar 14, and It is formed integrally with the tie bar 14. A second screw portion (not shown) is formed in the vicinity of the rear end surface of the rear platen 13, and the fixed platen 11 and the rear platen 13 are connected by screwing the second screw portion and the nut n2. The In the present embodiment, the guide post 21 is formed integrally with the tie bar 14, but the guide post 21 may be formed separately from the tie bar 14.

  A fixed mold 15 as a first mold is fixed to the fixed platen 11, and a movable mold 16 as a second mold is fixed to the movable platen 12. Accordingly, the fixed mold 15 and the movable mold 16 are brought into contact with and separated from each other, and mold closing, mold clamping, and mold opening are performed. As the mold clamping is performed, a plurality of cavity spaces (not shown) are formed between the fixed mold 15 and the movable mold 16, and the molding material injected from the injection nozzle 18 of the injection apparatus 17 is used as a molding material. Resin (not shown) is filled in each cavity space. A mold device 19 is configured by the fixed mold 15 and the movable mold 16.

  A suction plate 22 as a second movable member disposed in parallel with the movable platen 12 is disposed behind the rear platen 13 so as to be able to advance and retract along the guide posts 21 and is guided by the guide posts 21. Is done. The suction plate 22 is formed with guide holes 23 through the guide posts 21 at locations corresponding to the guide posts 21. The guide hole 23 is opened at the front end surface, and has a large diameter portion 24 that accommodates the ball nut n2 and a sliding surface that is opened at the rear end surface of the suction plate 22 and is slid with the guide post 21. A small diameter portion 25 is provided. In the present embodiment, the suction plate 22 is guided by the guide post 21, but the suction plate 22 can be guided not only by the guide post 21 but also by the guide Gd.

  By the way, in order to move the movable platen 12 forward and backward, a linear motor 28 as a first drive unit and as a mold opening / closing drive unit is disposed between the movable platen 12 and the frame Fr. The linear motor 28 includes a stator 29 as a first drive element and a mover 31 as a second drive element. The stator 29 is parallel to the guide Gd on the frame Fr. In addition, the movable platen 12 is formed corresponding to the moving range of the movable platen 12, and the movable element 31 is formed at a lower end of the movable platen 12 so as to face the stator 29 and over a predetermined range.

When the length of the stator 29 is Lp, the length of the movable element 31 is Lm, and the stroke of the movable platen 12 is Lst, the length Lm corresponds to the maximum propulsive force by the linear motor 28. And the length Lp is
Lp> Lm + Lst
To be.

  The mover 31 includes a core 34 and a coil 35. The core 34 includes a plurality of magnetic pole teeth 33 that are protruded toward the stator 29 and formed at a predetermined pitch, and the coil 35 is wound around the magnetic pole teeth 33. The magnetic pole teeth 33 are formed in parallel to each other in a direction perpendicular to the moving direction of the movable platen 12. The stator 29 includes a core (not shown) and a permanent magnet (not shown) formed to extend on the core. The permanent magnet is formed by magnetizing the N-pole and S-pole magnetic poles alternately and at the same pitch as the magnetic pole teeth 33.

  Accordingly, when the linear motor 28 is driven by supplying a predetermined current to the coil 35, the movable element 31 is advanced and retracted, and accordingly, the movable platen 12 is advanced and retracted to perform mold closing and mold opening. it can.

  In the present embodiment, the permanent magnet is disposed on the stator 29 and the coil 35 is disposed on the mover 31, but the coil is disposed on the stator and the permanent magnet is disposed on the mover. You can also. In this case, since the coil does not move as the linear motor 28 is driven, wiring for supplying power to the coil can be easily performed.

  By the way, when the movable platen 12 is moved forward and the movable mold 16 abuts against the fixed mold 15, the mold is closed and subsequently the mold is clamped. In order to perform mold clamping, an electromagnet unit 37 is disposed between the rear platen 13 and the suction plate 22 as a second driving unit and as a mold clamping driving unit. A rod 39 as a mold clamping force transmission member extending through the rear platen 13 and the suction plate 22 and connecting the movable platen 12 and the suction plate 22 is disposed so as to freely advance and retract. The rod 39 advances and retracts the suction plate 22 in conjunction with the advance and retreat of the movable platen 12 when the mold is closed and opened, and transmits the mold clamping force generated by the electromagnet unit 37 to the movable platen 12 during mold clamping. To do.

  The mold clamping device 10 is configured by the fixed platen 11, the movable platen 12, the rear platen 13, the suction plate 22, the linear motor 28, the electromagnet unit 37, the rod 39, and the like.

  The electromagnet unit 37 includes an electromagnet 49 as a first driving member formed on the rear platen 13 side, and an attracting portion 51 as a second driving member formed on the attracting plate 22 side. A predetermined portion of the front end surface of the attracting plate 22, in the present embodiment, is formed in a portion that surrounds the rod 39 and faces the electromagnet 49 in the attracting plate 22. In addition, in the present embodiment, two grooves 45 as coil arrangement portions having a rectangular cross-sectional shape are parallel to each other at a predetermined portion of the rear end surface of the rear platen 13, slightly above and below the rod 39. A core 46 having a rectangular shape is formed between the grooves 45, and a yoke 47 is formed in another portion. A coil 48 is wound around the core 46.

  In addition, although the said core 46 and the yoke 47 are comprised by the integral structure of a casting, they may be formed by laminating | stacking the thin plate which consists of a ferromagnetic material, and may comprise an electromagnetic laminated steel plate.

  In the present embodiment, the electromagnet 49 is formed separately from the rear platen 13, and the attracting portion 51 is formed separately from the attracting plate 22. The electromagnet is formed as a part of the rear platen 13, and the attracting portion is formed as a part of the attracting plate 22. It can also be formed.

  Therefore, in the electromagnet unit 37, when an electric current is supplied to the coil 48, the electromagnet 49 is driven to attract the attracting part 51 and generate the mold clamping force.

  The rod 39 is connected to the suction plate 22 at the rear end and is connected to the movable platen 12 at the front end. Therefore, the rod 39 is moved forward as the movable platen 12 moves forward when the mold is closed to advance the suction plate 22, and is moved backward as the movable platen 12 is moved backward when the mold is opened. Retreat.

  For this purpose, a hole 41 for penetrating the rod 39 and a hole 42 for penetrating the rod 39 are formed in the central portion of the rear platen 13 and the central portion of the suction plate 22. A bearing member Br1 such as a bush that slidably supports the rod 39 is provided facing the opening. Further, a screw 43 is formed at the rear end of the rod 39, and the screw 43 and a nut 44 as a mold thickness adjusting mechanism supported rotatably on the suction plate 22 are screwed together.

  By the way, when the mold closing is completed, the suction plate 22 is brought close to the rear platen 13, and a gap δ is formed between the rear platen 13 and the suction plate 22. However, the gap δ becomes too small or large. If it is too large, the adsorbing part 51 cannot be adsorbed sufficiently, and the mold clamping force becomes small. The optimum gap δ changes as the thickness of the mold apparatus 19 changes.

  Therefore, a large-diameter gear (not shown) is formed on the outer peripheral surface of the nut 44, and a die thickness adjusting motor (not shown) as a die thickness adjusting driving unit is disposed on the suction plate 22. A small-diameter gear attached to the output shaft of the motor is engaged with a gear formed on the outer peripheral surface of the nut 44.

  Then, when the mold thickness adjusting motor is driven according to the thickness of the mold device 19 and the nut 44 is rotated by a predetermined amount with respect to the screw 43, the position of the rod 39 with respect to the suction plate 22 is adjusted, The position of the suction plate 22 with respect to the fixed platen 11 and the movable platen 12 is adjusted, and the gap δ can be set to an optimum value. That is, the mold thickness is adjusted by changing the relative positions of the movable platen 12 and the suction plate 22.

  The mold thickness adjusting device is configured by the mold thickness adjusting motor, the gear, the nut 44, the rod 39, and the like. In addition, a rotation transmitting portion that transmits the rotation of the mold thickness adjusting motor to the nut 44 is constituted by the gear. The nut 44 and the screw 43 constitute a movement direction conversion unit, and the rotation direction of the nut 44 is converted into a straight movement of the rod 39 in the movement direction conversion unit. In this case, the nut 44 constitutes the first conversion element, and the screw 43 constitutes the second conversion element.

  Next, the operation of the mold clamping apparatus 10 having the above configuration will be described.

  When a new mold apparatus 19 is attached along with the replacement of the mold apparatus 19, first, the distance between the suction plate 22 and the movable platen 12 is changed in accordance with the thickness of the mold apparatus 19, and the mold is changed. Thickness adjustment is performed. In the mold thickness adjustment, the fixed mold 15 and the movable mold 16 are attached to the fixed platen 11 and the movable platen 12, respectively, and then the movable mold 16 is retracted to place the mold apparatus 19 in an open state. .

  Subsequently, in the distance adjusting step, the linear motor 28 is driven, and the movable mold 16 is brought into contact with the fixed mold 15 to perform a mold touch. At this time, no mold clamping force is generated. In this state, the mold thickness adjusting motor is driven to rotate the nut 44, and the distance between the rear platen 13 and the suction plate 22, that is, the gap δ is adjusted to a preset value.

  At this time, the coil 48 is embedded in the rear platen 13 so that the coil 48 is not damaged even if the rear platen 13 and the suction plate 22 come into contact with each other, and the coil 48 does not protrude from the surface of the rear platen 13. In this case, the surface of the rear platen 13 functions as a stopper for preventing damage to the coil 48.

  Thereafter, the mold opening / closing process means of the control unit (not shown) performs the mold opening / closing process, and supplies current to the coil 35 in the state of FIG. 2 when the mold is closed. Subsequently, the linear motor 28 is driven, the movable platen 12 is advanced, and the movable mold 16 is brought into contact with the fixed mold 15 as shown in FIG. At this time, a gap δ is formed between the rear platen 13 and the suction plate 22, that is, between the electromagnet 49 and the suction portion 51. Note that the force required for mold closing is sufficiently reduced compared to the mold clamping force.

  Subsequently, the mold opening / closing processing means supplies current to the coil 48 during mold clamping, and attracts the attracting portion 51 by the attracting force of the electromagnet 49. Along with this, the clamping force is transmitted to the movable platen 12 via the suction plate 22 and the rod 39, and clamping is performed. Under this structure, in this embodiment, when changing the mold clamping force, such as at the start of mold clamping, the control unit sets the target mold clamping force to be obtained by the change, that is, the target in a steady state. Clamping force The value of a steady current (hereinafter referred to as “rated current”) required to generate a mold clamping force (hereinafter referred to as “steady mold clamping force”). Control is performed so that the coil 48 is supplied.

  The mold clamping force is detected by a load detector (not shown), and the detected mold clamping force is sent to the control unit, and is supplied to the coil 48 so that the mold clamping force becomes a set value. Current is adjusted and feedback control is performed. During this time, the resin melted in the injection device 17 is injected from the injection nozzle 18 and filled in each cavity space of the mold device 19. As the load detector, a load cell disposed on the rod 39, a sensor for detecting the extension amount of the tie bar 14, or the like can be used.

  When the resin in each cavity space is cooled and solidified, the mold opening / closing means stops supplying current to the coil 48 in the state shown in FIG. 1 when the mold is opened. Along with this, the linear motor 28 is driven, the movable platen 12 is moved backward, and the movable mold 16 is placed in the retracted limit position as shown in FIG.

  In the present embodiment, the core 46, the yoke 47, and the suction plate 22 are all made of an electromagnetic laminated steel plate, but the periphery of the core 46 and the suction portion 51 in the rear platen 13 are electromagnetic laminated. You may make it comprise with a steel plate. In the present embodiment, an electromagnet 49 is formed on the rear end surface of the rear platen 13, and the attracting portion 51 is disposed on the front end surface of the attracting plate 22 so as to be capable of moving forward and backward. However, it is possible to dispose the electromagnet on the front end surface of the suction plate 22 so as to be able to advance and retreat, with the suction portion opposed to the suction portion on the rear end surface of the rear platen 13.

  In the present embodiment, the linear motor 28 is arranged as the first drive unit. However, instead of the linear motor 28, an electric motor, a hydraulic cylinder or the like is arranged. Can do. When the motor is used, the rotational rotational motion generated by driving the motor is converted into a linear motion by a ball screw as a motion direction conversion unit, and the movable platen 12 is advanced and retracted.

  By the way, in the present embodiment, the rear platen 13 and the suction plate 22 are laminated such that a directional electromagnetic steel sheet in which the direction in which the magnetic flux is most easily passed is aligned is such that the magnetic resistance is lower than the direction in which the magnetic flux passes by the electromagnet 49. And is formed by bonding by welding or the like.

  FIG. 3 is a diagram showing an example of a rear platen and a suction plate formed by laminating directional electromagnetic steel sheets in a direction in which the magnetic resistance decreases with respect to the direction in which the magnetic flux by the electromagnet passes.

  In (A) and (B) in the figure, the layered pattern shown on the rear platen 13 and the suction plate 22 indicates the direction in which the directional electrical steel sheets as the magnetic flux guiding members are laminated. Therefore, each layer may be viewed as a single grain-oriented electrical steel sheet. In the drawings, (A) and (B) show variations of the method of laminating grain-oriented electrical steel sheets in the rear platen 13, and in the following, explanations are common to (A) and (B). Do.

  In the rear platen 13, a portion indicated by 131 is laminated with directional electromagnetic steel sheets in the advancing and retreating direction of the rear platen 13, and functions as a vertical magnetic flux guiding member. In the directional electrical steel sheet in this portion, the direction in which magnetic flux easily passes (that is, the direction in which the magnetic resistance decreases) is the direction indicated by the arrow a131 (the direction that is substantially orthogonal (including orthogonal) to the advancing / retreating direction of the rear platen 13). It is arranged to be. Further, a portion indicated by 132 is laminated with a directional electromagnetic steel sheet in a direction orthogonal to the advancing / retreating direction of the rear platen 13 and functions as a horizontal magnetic flux guiding member. The grain-oriented electrical steel sheets in this portion are arranged so that the direction in which the magnetic flux is most easily passed is the direction indicated by the arrow a132 (the advancing / retreating direction of the rear platen 13).

  On the other hand, in the suction plate 22, a portion indicated by 221 has a directional electromagnetic steel plate laminated in a direction orthogonal to the advancing / retreating direction of the rear platen 13, and functions as a vertical magnetic flux guiding member. The grain-oriented electrical steel sheets in this portion are arranged so that the direction in which magnetic flux can easily pass is the direction indicated by arrow a221 (the traveling direction of the rear platen). A portion indicated by 222 is laminated with directional electromagnetic steel plates in the advancing and retreating direction of the rear platen 13 and functions as a horizontal magnetic flux guiding member. The directional electrical steel sheets in this portion are arranged so that the direction in which magnetic flux can easily pass is the direction indicated by the arrow a222 (the direction substantially perpendicular to the advancing / retreating direction of the rear platen 13).

  The reason why the magnetic resistance is lowered in the direction in which the magnetic flux by the electromagnet 49 passes through the rear platen 13 and the suction plate 22 by laminating the directional electromagnetic steel plates as shown in FIG.

  FIG. 4 is a diagram for explaining the relationship between how the magnetic flux passes through the rear platen and the suction plate and how to laminate the grain-oriented electrical steel sheets. The method of laminating the directional electrical steel sheets of the rear platen 13 and the suction plate 22 in FIGS. 4A and 4B is the same as in FIGS. 3A and 3B. Also in FIG. 4, (A) and (B) will be described in common.

  In the drawing, an arrow a <b> 1 indicates an example of a direction in which a magnetic flux passes through the electromagnet 49. Of the path of the arrow a1, for example, the portion 133 of the rear platen 13 (that is, the portion on the opposite side of the suction plate 22 across the coil 48) is such that the magnetic flux indicated by the arrow a1 is substantially in the forward / backward direction of the rear platen 13. Pass in the orthogonal direction. The portion 133 is a portion in which the grain-oriented electrical steel sheet is disposed such that the direction in which the magnetic resistance decreases is substantially orthogonal to the advancing / retreating direction of the rear platen 13. If it does so, in the part 133, the magnetic flux shown by arrow a1 will pass easily.

  Further, the portion 134 of the rear platen 13 (that is, a portion facing the opposing surface of the adsorption member and where the coil 48 is not present. In particular, adjacent to or close to the coil 48 in a direction orthogonal to the traveling direction of the rear platen 13. The magnetic flux indicated by the arrow a <b> 1 passes substantially in the advancing / retreating direction of the rear platen 13. The portion 134 is a portion where the grain-oriented electrical steel sheet is arranged in the direction in which the rear platen 13 advances and retreats in the direction in which the magnetic resistance decreases. Then, in the portion 134, the magnetic flux indicated by the arrow a1 can easily pass.

  Further, the magnetic flux indicated by the arrow a <b> 1 passes through a portion 223 (that is, a portion facing the coil 48) in the suction plate 22 in a direction substantially orthogonal to the advancing / retreating direction of the rear platen 13. The portion 223 is a portion in which the grain-oriented electrical steel sheet is disposed such that the direction in which the magnetic resistance decreases is substantially orthogonal to the advancing / retreating direction of the rear platen 13. If it does so, in the part 223, the magnetic flux shown by arrow a1 will pass easily.

  Further, in the portion 224 (that is, a portion that does not face the coil 48, particularly a portion that faces the portion 134) in the suction plate 22, the magnetic flux indicated by the arrow a <b> 1 passes substantially in the advancing and retreating direction of the rear platen 13. The portion 224 is a portion where the grain-oriented electrical steel sheet is arranged in the direction in which the rear platen 13 advances and retreats in the direction in which the magnetic resistance decreases. If it does so, in the part 224, the magnetic flux shown by the arrow a1 will pass easily.

  From the above, it can be said that the magnetic flux indicated by the arrow a1 is in a state where it can easily pass through most of the part. Therefore, according to the mold clamping device 10 in the present embodiment, the attractive force by the electromagnet 49 can be efficiently generated. That is, the characteristics of the magnetic circuit of the electromagnet 49 can be improved, and the rising response can be improved. Further, it is possible to reduce the magnetomotive force (current and the number of turns of the coil) and the adsorption area of the rear platen 13 and the adsorption plate 22 necessary for generating the desired adsorption.

  Here, comparing FIGS. 3A and 3B, in FIG. 3B, the horizontal magnetic flux guide member is disposed from one end of the rear platen to the other end. On the other hand, in the case of (A), the vertical direction magnetic flux guide member is arranged from the middle of the horizontal direction magnetic flux guide member. For this reason, in the structure of (A), the magnetic flux that has entered from the surface facing the suction plate 22 is more actively guided in the vertical direction by the vertical magnetic flux guide member than in the structure of (B). . Furthermore, in the structure of (A), since the upper and lower ends of the vertical direction magnetic flux guide member are outside air having a large magnetic resistance, the magnetic flux goes around the horizontal direction magnetic flux guide member. In addition, since the air layer is formed by the rod through hole in the central portion and the coil 48 is vertically symmetric, the magnetic flux of the vertical magnetic flux guiding member is positively circulated toward the horizontal magnetic flux guiding member. A magnetic circuit is constructed.

  It should be noted that all the parts of the rear platen 13 and the suction plate 22 do not have to be formed of directional electromagnetic steel plates. For example, the grain-oriented electrical steel sheet may be used only for a portion through which the magnetic flux by the electromagnet 49 passes or a portion through which a lot of magnetic flux passes. Such a portion corresponds to the portions 133, 134, 223, and 224 in FIG. 4, but all of these portions may not be formed of the grain-oriented electrical steel sheet. For example, even if a grain-oriented electrical steel sheet is used for one of these parts, the ease of passing of the magnetic flux can be improved for that part. Of course, if the portion using the grain-oriented electrical steel sheet is increased, the effect of the present invention can be obtained more remarkably.

  In the present embodiment, the example in which the present invention is applied to the mold clamping device that generates the mold clamping force by the attractive force shown in FIG. 1 and FIG. 2 is shown. The present invention may be applied to a mold clamping device that generates a mold clamping force by generating a repulsive force.

  As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the specific embodiment which concerns, In the range of the summary of this invention described in the claim, various deformation | transformation * It can be changed.

It is a figure which shows the state at the time of the mold closing of the metal mold apparatus and mold clamping apparatus in embodiment of this invention. It is a figure which shows the state at the time of the mold opening of the metal mold | die apparatus and mold clamping apparatus in embodiment of this invention. It is a figure which shows the example of the rear platen and adsorption | suction board which were formed by laminating | stacking a directional electromagnetic steel plate in the direction where magnetic resistance becomes low with respect to the direction through which the magnetic flux by an electromagnet passes. It is a figure for demonstrating the relationship between the way of the magnetic flux in a rear platen and an adsorption | suction board, and the lamination | stacking method of a directionality electromagnetic steel plate.

Explanation of symbols

10 mold clamping device 11 fixed platen 12 movable platen 13 rear platen 14 tie bar 15 fixed die 16 movable die 17 injection device 18 injection nozzle 19 mold device 21 guide post 22 suction plate 23 guide hole 24 large diameter portion 25 small diameter portion 28 linear Motor 29 Stator 31 Mover 37 Electromagnet unit 39 Rod 41, 42 Hole 43 Screw 44 Nut 45 Coil placement portion 46 Core 47 Yoke 48 Coil 49 Electromagnet 51 Adsorption portion 55 Auxiliary member 56 Mold material Br1 Bearing member Gd Guide Fr Frame n1 , N2 nut

Claims (9)

A mold clamping device having a coil holding member for holding a coil constituting an electromagnet and generating a clamping force by the electromagnet,
At least a part of the coil holding member is formed of a grain-oriented electrical steel sheet,
The die-clamping apparatus according to claim 1, wherein the grain-oriented electrical steel sheet is arranged in a direction in which a magnetic resistance is lowered with respect to a direction in which a magnetic flux by the electromagnet passes. In the coil holding member, having a suction member that forms a surface facing the surface on which the coil is held,
The coil holding member moves relative to the attracting member by an attracting force based on the electromagnet generated between a surface on which the coil is held and the facing surface of the attracting member,
The grain-oriented electrical steel sheet is disposed on the opposite side of the attracting member with the coil interposed therebetween so that the direction in which the magnetic resistance decreases is substantially perpendicular to the direction of relative movement of the coil holding member. The mold clamping apparatus according to claim 1, wherein: In the coil holding member, having a suction member that forms a surface facing the surface on which the coil is held,
The coil holding member moves relative to the attracting member by an attracting force based on the electromagnet generated between a surface on which the coil is held and the facing surface of the attracting member,
The grain-oriented electrical steel sheet is disposed at a location facing the facing surface of the attracting member such that a direction in which the magnetic resistance is reduced is a direction of relative movement of the coil holding member. The mold clamping device according to claim 1 or 2. At least a part of the adsorption member is formed of a grain-oriented electrical steel sheet,
4. The mold clamping apparatus according to claim 2, wherein the grain-oriented electrical steel sheet in the attracting member is arranged in a direction in which a magnetic resistance is lowered with respect to a direction in which a magnetic flux by the electromagnet passes.   The grain-oriented electrical steel sheet in the attracting member is disposed at a position facing the coil such that a direction in which the magnetic resistance is lowered is substantially orthogonal to a direction of relative movement of the coil holding member. The mold clamping device according to claim 4.   The grain-oriented electrical steel sheet in the attracting member is disposed at a location that does not face the coil so that the direction in which the magnetic resistance decreases is the direction of relative movement of the coil holding member. The mold clamping apparatus according to claim 4 or 5. A mold clamping device for generating a mold clamping force by an electromagnet,
A coil holding member for holding a coil constituting the electromagnet;
In the coil holding member, having a suction member that forms a surface facing the surface on which the coil is held,
At least a part of the adsorption member is formed of a grain-oriented electrical steel sheet,
The die-clamping apparatus according to claim 1, wherein the grain-oriented electrical steel sheet is arranged in a direction in which a magnetic resistance is lowered with respect to a direction in which a magnetic flux by the electromagnet passes. The coil holding member moves relative to the attracting member by an attracting force based on the electromagnet generated between a surface on which the coil is held and the facing surface of the attracting member,
The directional electrical steel sheet is disposed at a position facing the coil such that a direction in which the magnetic resistance is reduced is substantially orthogonal to a direction of relative movement of the coil holding member. 7. The mold clamping apparatus according to 7. The coil holding member moves relative to the attracting member by an attracting force based on the electromagnet generated between a surface on which the coil is held and the facing surface of the attracting member,
The directional electrical steel sheet is disposed at a location that does not face the coil such that the direction in which the magnetic resistance decreases is a direction of relative movement of the coil holding member. 8. The mold clamping apparatus according to 8.

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