JP3898565B2 - Magnetic adsorption holding device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention provides a magnetic adsorption holding device.In particular,The present invention relates to a structure in which a magnetic path can be formed between the object to be fixed and the object to be fixed even when the object is separated from the fixing surface.
[0002]
[Prior art]
  Conventionally, a magnetic adsorption holding device that attracts and fixes a workpiece such as a workpiece or a mold to be machined by applying a magnetic force is used in various machines used for machining, molding, etc. As an example of a machine provided with such a magnetic adsorption holding device, a case where it is applied to an injection molding machine will be described.
[0003]
  Generally, an injection molding machine has a pair of mold fixing plates for fixing a mold, and a bolt or a clamping device using hydraulic pressure is used as a means for fixing the mold to the mold fixing plate. Often used. However, in recent years, an injection molding machine in which a magnetic force is generated on a mold fixing surface for fixing a mold by the magnetic adsorption holding device and the mold is adsorbed and fixed by this magnetic force is being used. In this case, in the horizontal injection molding machine, the mold fixing surface is formed in a vertical plane, and the mold is fixed in a vertical posture on the mold fixing surface.
[0004]
  When fixing a die with a bolt or hydraulic clamp device, the fixing position of the die is limited by the arrangement of the bolt hole or the clamp device, whereas when fixing the die with a magnetic adsorption holding device There is no such restriction, and the degree of freedom in selecting the mold fixing position is high. Furthermore, if an AlNiCo magnet is used as a magnet for generating magnetic force, the magnetic pole of the magnet changes and is maintained by simply energizing the coil wound around the magnet for a few seconds. It is possible to easily generate a magnetic force on the fixed surface and to erase the magnetic force, thereby simplifying the replacement work of the mold (see, for example, JP-A-9-174559).
[0005]
[Problems to be solved by the invention]
  However, in the injection molding machine, when the mold is attracted and fixed to the mold fixing surface by the magnetic adsorption holding device, when the molded product is taken out from the mold, or when the impact force due to the mold opening is applied For example, if the mold is momentarily separated from the mold fixing surface, the suction force may be drastically reduced and the mold may fall from the mold fixing surface. Also, if the mold side surface that contacts the mold fixing surface is not flat due to various factors such as mold warpage and machining accuracy, a part of the mold will always be Since it is in a state of being separated from the fixed surface, the attractive force becomes weak and the mold is likely to fall. Such a problem can also occur in various machines having a magnetic adsorption holding device other than the injection molding machine.
  The object of the present invention is to form a magnetic path between a fixed body such as a workpiece and a mold, which is separated from the fixed surface, so that the fixed body falls or the fixing position thereof is reduced. It is an object of the present invention to provide a magnetic adsorption / holding device that can be made difficult to shift.
[0006]
[Means for Solving the Problems]
  The magnetic adsorption holding device according to claim 1 is provided with a plate member and a fixing surface for fixing a fixed body, and is fixed to the plate member.Made of magnetic materialA plurality of block members and a magnetic force that attracts and fixes the object to be fixed to the fixed surface are generated.Can holdIn addition, a magnetic attraction and holding device including a magnetic force generation and holding mechanism that causes the magnetic force to act on the fixed body via a plurality of block members,The magnetic force generation and holding mechanism includes a plurality of permanent magnets disposed around the plurality of block members, a plurality of alnico magnets disposed on the opposite side of the fixed surface with respect to the plurality of block members, and a plurality of A plurality of coils wound around each of the Alnico magnets,Each block member is provided with a magnetic force holding member made of a magnetic material capable of moving back and forth in a direction perpendicular to the fixed surface and partially protruding from the fixed surface.In addition, a locking member for locking the magnetic force holding member so as not to protrude from a predetermined protruding position is fixedly provided on the block member,The magnetic force holding member is attracted to the fixed body when the fixed body is fixed to the fixed surface.A magnetic path through which part of the magnetic flux generated by the magnetic force generation and holding mechanism passesIn addition, when the object to be fixed is separated from the fixing surface, it is configured to hold the state of being adsorbed to the object to be fixed within a predetermined distance.
[0007]
  The magnetic force generation and holding mechanism includes a plurality of permanent magnets arranged around a plurality of block members, a plurality of alnico magnets, and a plurality of coils wound around the plurality of alnico magnets, respectively.In this magnetic adsorption holding device, when a fixed object such as a workpiece to be machined or an injection molding die is fixed to the fixed surface by suction,Multiple permanent magnetsThus, a magnetic force is generated on the fixed surface to hold the magnetic force, and the magnetic force is applied to the fixed body via the plurality of block members. When releasing the object to be fixed, turn on the coil for several seconds.Of alnico magnetReverse the magnetic polesThe state can be maintained by switching to a state in which the magnetic flux of the plurality of permanent magnets does not go outside the fixed surface.
[0008]
  Each block member is provided with a magnetic force holding member that can move forward and backward in the direction perpendicular to the fixed surface.In addition, a locking member for locking the magnetic force holding member so as not to protrude from a predetermined protruding position is fixedly provided on the block member.ing. In a state where the fixed body is fixed to the fixed surface, the magnetic force holding member is in a state of being retracted into the block member while adsorbing to the fixed body.
  Here, when a large impact force or the like acts on the fixed body and the fixed body is separated from the fixing surface, the magnetic force acting on the fixed body is rapidly reduced. However, the fixed body is separated from the fixed surface, creating a gap.EvenMagnetic holding memberFixed objectPartly protruding while adsorbed onConfigure magnetic pathTherefore, the state in which the magnetic force holding member is attracted to the fixed body can be held within a predetermined separation distance. Therefore, even in the part separated from the fixing surface of the fixed body, the magnetic force holding member is interposed.MagneticSince the path is configured, it is difficult for the body to be fixed to fall from the fixing surface or to shift its fixing position.When the fixed body is separated from the fixed surface by the predetermined separation distance and the magnetic force holding member is in the predetermined protruding position, the magnetic force holding member is locked by the locking member. Deviation is suppressed.
[0009]
  In addition, if the surface of the fixed body that contacts the fixed surface is not formed flat due to factors such as warpage of the fixed body and machining accuracy, a part of the fixed body is always separated from the fixed surface. Even in this case, since the magnetic force holding member protrudes from the fixed surface and is attracted to the mold, even in such a portion separated from the fixed surface,Because the magnetic force holding member constitutes the magnetic path,Since the magnetic force acting on the fixed body is not significantly reduced, the fixed body is unlikely to drop or the fixing position on the fixing surface is unlikely to shift.
[0010]
According to a second aspect of the present invention, there is provided a magnetic adsorption / holding device according to the first aspect of the present invention, in which the magnetic force is retained between the fixed body and the block member via the magnetic force holding member while the magnetic force holding member is attracted to the fixed body. The road is constructed. Therefore, even when a large impact force or the like acts on the fixed body and the fixed body is separated from the fixing surface, a magnetic path is formed between the fixed body and the block member via the magnetic force holding member. Since the magnetic force acting on the fixed body does not drop significantly, it is difficult for the fixed body to fall or for the fixed position on the fixed surface to shift.
[0011]
  According to a third aspect of the present invention, there is provided a magnetic adsorption holding device comprising: a plate member fixed to a plate surface of a mold fixing plate for fixing the die to a mold fixing plate of an injection molding machine; Multiple fixedMade of magnetic materialGenerates a magnetic force that attracts the block member and the mold to the mold fixing surface.Can holdIn addition, a magnetic adsorption holding device provided with a magnetic force generation holding mechanism that causes the magnetic force to act on the mold through a plurality of block members,The magnetic force generation and holding mechanism includes a plurality of permanent magnets disposed around the plurality of block members, and a plurality of alnico magnets disposed on the opposite side of the mold fixing surface with respect to the plurality of block members. A plurality of coils each wound around a plurality of alnico magnets,Each block member is provided with a magnetic force holding member made of a magnetic material capable of moving back and forth in a direction perpendicular to the mold fixing surface and partially protruding from the mold fixing surface.In addition, a locking member for locking the magnetic force holding member so as not to protrude from a predetermined protruding position is fixedly provided on the block member,The magnetic force holding member is attracted to the mold when the mold is fixed to the mold fixing surface.A magnetic path through which part of the magnetic flux generated by the magnetic force generation and holding mechanism passesIn addition, when the mold is separated from the mold fixing surface, it is configured to maintain the state of being attracted to the mold within a predetermined separation distance.
[0012]
  Since the action of this magnetic adsorption holding device is almost the same as that of Claim 1, it will be briefly explained. When the molded product is taken out or when the impact force at the time of mold opening acts on the mold, the mold is When separated from the mold fixing surface, the magnetic force holding member is partly protruding while adsorbing to the mold.Configure magnetic pathTherefore, the state in which the magnetic force holding member is attracted to the mold can be held within the range of the predetermined separation distance. Therefore, even in a portion of the mold separated from the mold fixing surface, the magnetic force acts through the magnetic force holding member, and the magnetic force acting on the mold is not significantly reduced. It becomes difficult to fall.
[0013]
  According to a fourth aspect of the present invention, there is provided a magnetic adsorption / holding device according to the third aspect, wherein a magnetic path is provided between the mold and the block member via the magnetic force holding member while the magnetic force holding member is attracted to the mold. It is characterized by being configured. Therefore, even when the mold is separated from the mold fixing surface, a magnetic path is formed between the mold and the block member via the magnetic force holding member so that the magnetic force acts on the mold and the magnetic force acting on the mold. Does not drop significantly, making it difficult for the mold to fall.
[0014]
  According to a fifth aspect of the present invention, there is provided the magnetic adsorption holding device according to any one of the first to fourth aspects, wherein each block member is provided with a biasing member that biases the magnetic force holding member toward the protruding side. It is. Therefore, by always urging the magnetic force holding member to the protruding side by the urging force of the urging member, the mold can be removed when the molded product is taken out or when the impact force when the mold is opened is applied to the mold. When separated from the mold fixing surface, the magnetic force holding member can be reliably projected and attracted to the mold.
[0015]
  According to a sixth aspect of the present invention, in the invention of any one of the first to fifth aspects, the block member is provided with a plurality of magnetic force holding members. Even when the mold is separated from the mold fixing surface, the state in which the plurality of magnetic force holding members are attracted to the mold is maintained, so that the magnetic force acting on the mold via the magnetic force holding member increases, It becomes difficult to fall.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described. The present embodiment is an example in which the present invention is applied to a horizontal injection molding machine including a pair of mold fixing plates facing each other in the horizontal direction. First, the injection molding machine 1 will be briefly described.
  As shown in FIG. 1, the injection molding machine 1 includes a fixed plate 2 and a movable plate 3 (mold fixed plate) for fixing a fixed mold 2a and a movable mold 3a, and mold clamping of the molds 2a and 3a. In order to open the mold, the movable platen drive mechanism 4 having a ram 4a for driving the movable platen 3 in the direction of approaching / separating from the fixed platen 2 and the movable platen 3 are guided to be movable in the approaching / separating direction. Resin supply mechanism 6 having four guide rods 5 to be supported, an injection cylinder 6a for supplying molten synthetic resin to cavities formed in the molds 2a and 3a in a clamped state, and a movable mold An eject mechanism (not shown) for taking out a molded product from 3a is provided.
[0017]
  When a molding operation is performed by the injection molding machine 1, the movable platen 3 is driven by the ram 4a in a direction approaching the fixed platen 2, and the movable die 3a is pressed against the fixed die 2a to be in a clamped state. In this state, molten synthetic resin is supplied into the molds 2a and 3a from the tip of the injection cylinder 6a having a screw conveyor-like pressurizing member therein, and the molded product is injection-molded. After that, the ram 4a drives the movable platen 3 in the direction away from the fixed platen 2, and the movable die 3a is separated from the fixed die 2a to be in the mold open state. In this state, the molded product is taken out from the movable mold 3a by the eject mechanism.
[0018]
  Next, the fixed platen 2 and the movable platen 3 will be described. Since the fixed platen 2 and the movable platen 3 have substantially the same structure, the fixed platen 2 will be described below.
  As shown in FIGS. 1 and 2, the stationary platen 2 is formed in a square shape in a side view, and insertion holes 2b for inserting guide rods 5 are provided in the vicinity of the four corners, respectively. The guide rods 5 are fixed to the stationary platen 2 in a state of being inserted through the four insertion holes 2b. The fixed platen 2 is provided with a mold suction fixing device 10 (corresponding to a magnetic suction holding device) for fixing the die 2a to the fixed platen 2.
[0019]
  As shown in FIGS. 2 to 6, the die suction fixing device 10 includes a plate member 11 fixed to the plate surface 2 c of the fixed platen 2, and four blocks fixed to the plate member 11 having a die fixing surface 12 a. A magnetic force generation / holding mechanism 13 that generates a magnetic force for attracting the member 12 and the mold 2a to the mold fixing surface 12a and holds the magnetic force, and acts on the mold 2a via the four block members 12. And.
[0020]
  As shown in FIG. 2, the plate member 11 is formed in a substantially square shape when viewed from the side. The plate member 11 is positioned in a groove 2 d formed in the fixed platen 2, and a bolt 20 is provided at the center of the fixed platen 2. It is fixed with. Four block members 12 made of a magnetic material are fixed to the plate member 11 with bolts 21 made of a non-magnetic material (for example, SUS304), and a vertical mold fixing surface 12a is provided on the left surface of each block member 12. Is formed. Further, as will be described in detail later, each block member 12 includes four magnetic members that can advance and retreat in a direction perpendicular to the mold fixing surface 12a and can partially protrude leftward from the mold fixing surface 12a. A magnetic force holding member 30 and four coil springs 31 (urging members) for urging the four magnetic force holding members 30 to the protruding side are provided.
[0021]
  As shown in FIGS. 4 and 5, the magnetic force generation and holding mechanism 13 includes a plurality of permanent magnets 22 disposed around the four block members 12, and the right side of the four block members 12 (the mold fixing surface 12 a and Four alnico magnets 23 disposed on the opposite side) and four sets of coils 24 wound around the four alnico magnets 23, respectively. When the coil 2a is fixed to the mold fixing surface 12a, when the coil 24 is energized for a few seconds in a predetermined direction, the direction of the magnetic flux by the alnico magnet 23 in the block member 12 is the permanent magnet 22 as shown in FIG. The magnetic pole of the alnico magnet 23 changes so as to be the same as the direction of the magnetic flux due to. Therefore, a magnetic flux passes between the mold 2a and the mold adsorption fixing device 10 as shown by a chain line in FIG. 4, and the mold 2a is fixed to the mold fixing surface 12a.
[0022]
  On the other hand, when releasing the fixation of the mold 2a, if the coil 24 is energized for several seconds in the opposite direction to the case of fixing the mold 2a, the magnetic pole of the alnico magnet 23 is reversed and the block member 12 The magnetic flux generated by the alnico magnet 23 does not come out of the mold fixing surface 12a. Therefore, as indicated by a chain line in FIG. 5, the magnetic flux passes only inside the mold adsorption fixing device 10, and no magnetic force acts on the mold 2a, so that the mold 2a is fixed.
[0023]
  Next, the magnetic force holding member 30 unique to the present application will be described. However, since the four magnetic force holding members 30 have the same structure, one of them will be described below.
  As shown in FIGS. 4 to 6, the magnetic force holding member 30 is formed of a magnetic body (for example, S45C) in a substantially cylindrical shape, and the magnetic force holding member 30 is slid in the left-right direction in the accommodation hole 12 b formed in the block member 12. It is fitted in freely. Of the magnetic force holding member 30Tip surfaceIs formed with a suction surface 30a for suction to the mold 2a. Further, the magnetic force holding member 30 is a bolt 32 made of a non-magnetic material (for example, SUS304) that is screwed into the block member 12.(Corresponding to the locking member)Is inserted. An annular engagement portion 30b formed on the inner peripheral portion of the right end portion of the magnetic force holding member 30 can be engaged with the bolt 32, and the magnetic force holding member 30 is restricted from coming out to the left from the accommodation hole 12b. . A coil spring 31 is disposed at the right end of the accommodation hole 12b, and the magnetic force holding member 30 is elastically biased leftward by the coil spring 31.
[0024]
  In a state where the magnetic force generated by the magnetic force generation and holding mechanism 13 is applied to the mold 2a and the mold 2a is fixed to the mold fixing surface 12a, the magnetic force holding member 30 is a coil spring as shown by the solid line in FIG. Retreating to the right against the urging force of 31, the attracting surface 30 a of the magnetic force holding member 30 is attracted to the mold 2 a in the same plane as the mold fixing surface 12 a.
[0025]
Here, for example, when the mold 2a is momentarily separated from the mold fixing surface 12a when the molded product is taken out by the eject mechanism or when the impact force when the mold is opened is applied to the mold, it will be described later. As shown by the chain line in FIG. 6, the magnetic force holding member 30 protrudes to the left due to the urging force of the coil spring 31, and the bolt 32 has an annular engagement portion 30b. Is engagedTo the specified protruding positionIn the range of a predetermined separation distance (for example, 3 mm) up to, the magnetic force holding member 30 is held in a state of being reliably adsorbed to the mold 2a. Thus, while the magnetic force holding member 30 is attracted to the mold 2a, a magnetic path is formed between the mold 2a and the block member 12 via the magnetic force holding member 30, and the magnetic force is applied to the mold 2a. Works.
[0026]
In addition, as shown in FIG. 7, due to factors such as warpage of the mold 2a and machining accuracy, the surface of the mold fixing surface that contacts the mold fixing surface 12a is not formed flat. Although a part of the mold 2a is always separated from the mold fixing surface 12a, the state in which the magnetic force holding member 30 protrudes from the mold fixing surface 12a and is attracted to the mold 2a is maintained. Is done.
[0027]
  Next, the change in magnetic force generated by the magnetic force generation and holding mechanism 13 and acting on the mold 2a when the mold 2a is separated from the mold fixing surface 12a will be described in detail.
  As shown in FIGS. 8A and 8B, in the residual magnetic flux density Br-coercive force Hc demagnetization characteristics, the demagnetization characteristics of the permanent magnet 22 and the Alnico magnet 23 are represented by La and Lb, respectively. Here, Bra and Brb are residual magnetic flux densities remaining in the respective magnets 22 and 23 when the magnetic field H is zero.
[0028]
  Here, the magnetic force generation and holding mechanism of the present invention generates a magnetic force by combining a plurality of permanent magnets 22 and an alnico magnet 23, and the change in the magnetic force is uniquely determined from the demagnetization characteristics of a single magnet. However, it is possible to grasp the trend of the change.
[0029]
  That is, when there is no gap between the mold 2a and the mold fixing surface 12a, the inclination of the permeance line is large. That is, the permeance coefficient (Br / Hc) is large. On the other hand, since the inclination of the permeance line is smaller when there is a gap, the permeance coefficient is smaller than when there is no gap.
[0030]
  Here, the demagnetization characteristic, the permeance line, and the operating point of the magnet will be described. In the case of a single magnet, the demagnetization characteristic and the permeance line become clear, and Br and Hc of the operating point can be obtained. Further, the residual magnetic flux density Br ′ when the gap is returned to the state without the gap is on the recoil wire and can be obtained.
  In the case of an alnico magnet, Br ′ <Br, and in the case of a permanent magnet such as ferrite or neodymium, it generally moves on a demagnetization curve and Br′≈Br. However, in the case of the magnetic adsorption holding device, a plurality of alnico magnets, neodymium magnets, and the like are used, and it is extremely difficult to determine the permeance line in this case.
  However, the tendency of the value of Br ′ determined by the inclination of the permeance line and the recoil line can be compared with and without a gap.
[0031]
That is, as shown in FIG. 8, in the permanent magnet 22, when the permeance line in a state where the mold 2a is not separated from the mold fixing surface 12a is L1, the permanent magnet 22 in this state is La and L1. The magnetic flux density from the permanent magnet 22 is B1. From this state, when the mold 2a is separated from the mold fixing surface 12a and a gap of a predetermined amount is generated, the permeance line is L2, and the operating point is P2, so that the magnetic flux density from the permanent magnet 22 is B2. It becomes and decreases.
  However, when the mold 2a is separated from the mold fixing surface 12a and a predetermined amount of gap is generated, if the magnetic force holding member 30 is attracted to the mold 2a, the permeance line is L3 and the operating point is P3. Therefore, the magnetic flux density from the permanent magnet 22 is B3 (B2 <B3 <B1).
[0032]
  Similarly, in the Alnico magnet 23, if the permeance line is L4 when the mold 2a is not separated from the mold fixing surface 12a, the operating point is P4 which is the intersection of Lb and L4. The magnetic flux density is B4. In this state, when the mold 2a is separated from the mold fixing surface 12a and a predetermined amount of gap is generated, the permeance line is L5 and the operating point is P5. Therefore, the magnetic flux density of the Alnico magnet 23 is B5. descend.
However, when the mold 2a is separated from the mold fixing surface 12a and a predetermined amount of gap is generated, if the magnetic force holding member 30 is attracted to the mold 2a, the permeance line is L6 and the operating point is P6. Therefore, the magnetic flux density from the alnico magnet 23 is B6 (B5 <B6 <B4).
[0033]
  Here, the magnetic force F acting on the mold fixing surface 12a is F = KB.²Since it is obtained by S (S is the area of the part through which the magnetic flux passes and K is a constant), the magnetic force F increases as the magnetic flux density B increases. Therefore, when the magnetic force holding member 30 is attracted to the mold 2a when the mold 2a is separated from the mold fixing surface 12a, the magnetic force generated by the permanent magnet 22 and the alnico magnet 23 is separated from the mold 2a. Although it is reduced from the state where there is no magnetic force, it is predicted that the degree of the reduction is surely suppressed as compared with the case where the magnetic force holding member 30 is not provided.
[0034]
  However, even in this case, if the magnetic flux density B6 of the magnetic flux by the alnico magnet 23 is smaller than the magnetic flux density B3 of the magnetic flux by the permanent magnet 22, the magnetomotive force of the alnico magnet 23 is lower than the magnetomotive force of the permanent magnet 22. In addition, a part of the magnetic flux of the permanent magnet 22 may be divided and passed to the alnico magnet 23 from the mold fixing surface 12a without passing to the outside. In this case, the magnetic force generated on the mold fixing surface 12a is the magnetic flux. Will be reduced by the amount divided.
[0035]
  In order to confirm the change in magnetic force predicted as described above, the results of the experiment conducted by the applicant of the present application are illustrated.9Shown in Here, the curves A and B indicate the reduction rate of the adsorption force with respect to the adsorption force (8,400 N in the experiment) when there is a gap between the mold 2a and the mold fixing surface 12a and when there is no gap. , A is when the magnetic force holding member 30 is not provided, and B is when the magnetic force holding member 30 is adsorbed to the mold 2a. As is clear from this experimental result, even when a gap is generated between the mold 2a and the mold fixing surface 12a, when the magnetic force holding member 30 is attracted to the mold 2a, the magnetic force holding member 30 is not provided. Compared to the above, it is possible to remarkably reduce the decrease in adsorption power.
[0036]
  Next, the operation of the mold suction fixing device 10 will be described.
  First, in the stationary platen 2, the stationary mold 2a is moved to the vicinity of a predetermined fixed position by a mold transportation mechanism (not shown) disposed on the side of the injection molding machine 1 or transportation means such as a crane. Next, when the coil 24 is energized for several seconds in a predetermined direction, the magnetic pole of the alnico magnet 23 is changed and the state is maintained, and a magnetic flux as shown in FIG. 4 is generated, and the mold fixing surface 12a is subjected to the metal mold. A magnetic force for fixing the mold 2a is generated. When the mold 2a is fixed to the mold fixing surface 12a by this magnetic force, at the same time, the magnetic force holding member 30 retreats to the right against the urging force of the coil spring 31, and as shown by the solid line in FIG. The adsorption surface 30a of the magnetic force holding member 30 is adsorbed to the mold 2a in the same plane as the mold fixing surface 12a, and the adsorption surface 30a causes a magnetic force to act on the mold 2a together with the mold fixing surface 12a. Similarly, in the movable platen 3, the movable mold 3a is fixed to the mold fixing surface 12a.
[0037]
  When the molds 2a and 3a are instantaneously separated from the mold fixing surface 12a due to impact or the like when the mold is opened with the molds 2a and 3a being fixed to the mold fixing surface 12a, Although the magnetic force acting on the molds 2a and 3a suddenly weakens, at the same time, as indicated by the chain line in FIG. 6, the magnetic force holding member 30 protrudes to the left by the urging force of the coil spring 31, and the annular engagement portion 30b Within the range of a predetermined separation distance until engaging with 32, the magnetic force holding member 30 is held in the state of being attracted to the molds 2a and 3a. Accordingly, since a magnetic path is formed between the mold 2a and the block member 12 via these magnetic force holding members 30, a magnetic force having a predetermined strength acts on the molds 2a and 3a even in this case. .
[0038]
  When releasing the molds 2a and 3a, if the coil 24 is energized for several seconds in the direction opposite to that when the mold is fixed, the magnetic pole of the alnico magnet 23 is reversed, as shown in FIG. The magnetic flux passes only inside the mold adsorption fixing device 10, and the magnetic force does not act on the molds 2a and 3a.
[0039]
  As shown in FIG. 6, when the surfaces of the molds 2a and 3a that are in contact with the mold fixing surface 12a are not formed flat due to factors such as warpage of the molds 2a and 3a and machining accuracy. In this case, a part of the molds 2a and 3a is separated from the mold fixing surface 12a, but in this case also, the magnetic force holding member 30 protrudes from the mold fixing surface 12a to the molds 2a and 3a. Because of the adsorption, a magnetic force having a predetermined strength acts on the molds 2a and 3a via the magnetic force holding member 30 even in a portion separated from the mold fixing surface 12a.
[0040]
  According to the mold adsorption fixing device 10 described above, a decrease in magnetic flux density can be suppressed with a small magnetic path configuration, and the following effects can be obtained without significantly reducing the adsorption force of the entire block member 12. Can do.
1) When the molds 2a and 3a are separated from the mold fixing surface 12a when the molded product is taken out by the eject mechanism, or the surfaces on the mold 2a and 3a side contacting the mold fixing surface 12a are formed flat. Even when part of the molds 2a and 3a is not separated from the mold fixing surface 12a, the magnetic force holding member 30 protrudes from the mold fixing surface 12a and is attracted to the molds 2a and 3a. A magnetic path is formed between the molds 2a, 3a and the block member 12 via the holding member 30, and a predetermined magnetic force acts on the molds 2a, 3a via the magnetic force holding member 30, so that the mold 2a , 3a becomes difficult to fall.
[0041]
  2) The magnetic force generation and holding mechanism 13 includes a plurality of permanent magnets 22 disposed around the four block members 12 and four disposed on the opposite side of the four block members 12 from the mold fixing surface 12a. Since the Alnico magnet 23 and the four sets of coils 24 wound around the four Alnico magnets 23 are provided, the magnetic poles of the Alnico magnet 23 are reversed and the state is maintained only by energizing the coils 24. The molds 2a and 3a can be easily fixed to the mold fixing surface 12a, or the fixing can be released, and the replacement work of the molds 2a and 3a is easy. Further, it is not necessary to supply power to the mold adsorption / fixation device 10 while the mold adsorption / fixation device 10 is fixing the molds 2a, 3a, and the adsorption power of the molds 2a, 3a is lost during a power failure. There is nothing. Furthermore, power consumption is reduced, which is advantageous in terms of operating costs.
[0042]
  3) Since each block member 12 is provided with a coil spring 31 that biases the magnetic force holding member 30 toward the protruding side, the magnetic force is held by the coil spring 31 when the molds 2a and 3a are separated from the mold fixing surface 12a. By biasing the member 30 to the left, the magnetic force holding member 30 can be reliably attracted to the molds 2a and 3a.
[0043]
  Next, modified embodiments in which various modifications are made to the embodiment will be described. In addition, about the thing similar to the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted suitably.
  1] The number of the magnetic force holding members 30 provided in the block member 12 is not limited to four in the above embodiment, but may be one or a plurality other than four. However, when the molds 2a and 3a are separated from the mold fixing surface 12a, the magnetic force acting on the molds 2a and 3a through the magnetic force holding member 30 is increased so that the molds 2a and 3a are not easily dropped. In addition, it is desirable to increase the number of the magnetic force holding members 30 while increasing the attracting surface 30 a of each magnetic force holding member 30.
  2] As the urging member, various members such as a plate spring, a disc spring, an elastic member made of synthetic rubber or synthetic resin can be used in addition to the coil spring 31.
[0044]
3] Modification 1 ... See FIG.
As shown in FIG. 10, a magnetic force holding member 40 is slidably fitted in a receiving hole 42b formed in the block member 42, and the magnetic force holding member 40 is received by a disc spring 41 received at the right end of the receiving hole 42b. It is elastically biased to the left. A ring member 43 is press-fitted into the left end of the accommodation hole 42b. An annular engagement portion 40a formed at the right end of the magnetic force holding member 40 can be engaged with the ring member 43, and the magnetic force holding member 40 is restricted from coming out to the left from the accommodation hole 42b. Also in this modified embodiment 1, as in the above-described embodiment, when the mold 2a is separated from the mold fixing surface 42a, a predetermined separation distance until the annular engagement portion 40b engages with the ring member 43 is obtained. 10, the magnetic force holding member 40 protrudes to the left, the suction surface 40 a is attracted to the mold 2 a, and the magnetic force acts on the mold 2 a via the magnetic force holding member 40. .
[0045]
4] Modification 2 ... See FIG.
As shown in FIG. 11, an annular magnetic force holding member 50 is slidably fitted on a bolt 53 and slidably fitted in a receiving hole 52 b formed in the block member 52. The magnetic force holding member 50 is elastically biased leftward by a disc spring 51 accommodated in the right end of the accommodation hole 52b. An annular engagement portion 50b formed at the right end of the magnetic force holding member 50 can be engaged with the bolt 53, and the magnetic force holding member 50 is restricted from coming out to the left from the accommodation hole 52b. Also in this modified embodiment 2, as in the above embodiment, when the mold 2a is separated from the mold fixing surface 52a, a predetermined separation distance until the annular engagement portion 50b engages with the bolt 53 is obtained. 11, the magnetic force holding member 50 protrudes to the left to attract the suction surface 50 a to the mold 2 a, and the magnetic force acts on the mold 2 a via the magnetic force holding member 50. .
[0046]
  5] When the mold 2a is separated from the mold fixing surfaces 12a, 42a, 52a and a gap is formed between the mold fixing surfaces 12a, 42a, and 52a in the embodiment and the modifications 1 and 2 thereof, the surface on the mold fixing surface side of the mold 2a Opposing magnetic poles are formed between the mold fixing surfaces 12a, 42a, and 52a, and the magnetic force holding members 30, 40, and 50 partially protrude while being attracted to the mold 2a by the magnetic force caused by the magnetic poles generated on both surfaces. Therefore, the biasing members such as the coil spring 31 and the disc springs 41 and 51 that bias the magnetic force holding members 30, 40, and 50 to the protruding side can be omitted.
  6] The magnetic adsorption holding device of the present invention is not limited to the case where the mold is adsorbed and fixed in the injection molding machine, but the case where another object to be fixed is fixed, such as the case where the workpiece to be machined is adsorbed and fixed to the fixing surface. It can also be applied to.
[0047]
【The invention's effect】
  According to the first aspect of the present invention, each block member is provided with a magnetic force holding member made of a magnetic material that can move forward and backward in a direction perpendicular to the fixed surface and can partially protrude from the fixed surface. In the state that the fixed body is fixed to the fixed surface,Configure magnetic pathAt the same time, when the object to be fixed is separated from the fixing surface, the state of being adsorbed to the object to be fixed is maintained within a predetermined distance, so that the following effects can be obtained.
[0048]
  When a large impact force acts on the fixed body and the fixed body is separated from the fixed surface, the magnetic force acting on the fixed body is drastically reduced. Partially protruding while adsorbed on the moldAnd configure the magnetic pathThe range of the specified separation distance(A range that does not protrude beyond the specified protruding position)The state in which the magnetic force holding member is attracted to the fixed body can be held. Therefore, even in the part separated from the fixing surface of the fixed body, the magnetic force holding member is interposed.MagneticSince the path is configured, it becomes difficult for the fixed body to fall from the fixing surface or to shift the fixing position.
[0049]
  In addition, if the surface of the fixed body that contacts the fixed surface is not formed flat due to factors such as warpage of the fixed body and machining accuracy, a part of the fixed body is always separated from the fixed surface. In this case as well, the magnetic force holding member protrudes from the fixed surface and is attracted to the mold, so that the magnetic force acting on the fixed body is greatly increased even in the part separated from the fixed surface. It is difficult for the fixed body to fall or the fixing position on the fixing surface to shift.
[0050]
  According to the invention of claim 2, while the magnetic force holding member is adsorbed to the fixed body, a magnetic path is formed between the fixed body and the block member via the magnetic force holding member. Even when a large impact force acts on the body and the object to be fixed is separated from the fixing surface, a magnetic path is formed between the object to be fixed and the block member via the magnetic force holding member, and the object to be fixed acts on the object. The magnetic force is not significantly reduced, and it is difficult for the fixed body to drop or the fixing position on the fixing surface to shift.
[0051]
  According to the invention of claim 3, when the mold of the injection molding machine is adsorbed and fixed to the mold fixing surface, when the molded product is taken out or when the impact force at the time of mold opening acts on the mold, etc. Even if the mold is separated from the mold fixing surface, the magnetic force holding member is partly protruding while adsorbing to the moldAnd configure the magnetic pathTherefore, the state in which the magnetic force holding member is attracted to the mold can be held within the range of the predetermined separation distance. Accordingly, the magnetic force holding member is also provided in the part of the mold separated from the mold fixing surface.To make up the magnetic pathThe magnetic force acting on the mold is not significantly reduced, and the mold is less likely to drop from the mold fixing surface.
[0052]
  According to the fourth aspect of the present invention, since the magnetic path is formed between the mold and the block member through the magnetic force holding member while the magnetic force holding member is attracted to the mold, Even when separated from the mold fixing surface, a magnetic path is formed between the mold and the block member via the magnetic force holding member, and the magnetic force acts on the mold, so that the magnetic force acting on the mold is greatly reduced. This makes it difficult for the mold to fall.
[0053]
  According to the invention of claim 5, since the urging member for urging the magnetic force holding member to the protruding side is provided in each block member, the magnetic force holding member is always urged to the protruding side by the urging force of the urging member. Therefore, when the mold is separated from the mold fixing surface, such as when the molded product is taken out or when the impact force when the mold opens is applied to the mold, Can be adsorbed to the mold. In addition, the same effect as any one of claims 1 to 4 can be obtained.
[0054]
  According to the invention of claim 6, since each block member is provided with a plurality of magnetic force holding members, even when the mold is separated from the mold fixing surface, the state in which the plurality of magnetic force holding members are attracted to the mold is present. Since it is held, the magnetic force acting on the mold via the magnetic force holding member is increased, and the mold is difficult to drop. In addition, the same effect as any one of claims 1 to 5 can be obtained.
[Brief description of the drawings]
FIG. 1 is a front view of an injection molding machine according to an embodiment of the present invention.
FIG. 2 is a left side view of the fixed platen.
FIG. 3 is a partially enlarged view of FIG. 2;
4 is a cross-sectional view taken along line IV-IV in FIG. 2 in a state where the mold is fixed.
FIG. 5 is a view corresponding to FIG. 4 in a state where the mold fixing is released.
6 is an enlarged view of a main part of FIG.
FIG. 7 is a view corresponding to FIG. 4 when the mold is warped.
FIG. 8 is a diagram showing demagnetization characteristics and permeance lines of a permanent magnet and an alnico magnet.
FIG. 9 is a diagram showing a relationship between a gap between a mold and a mold fixing surface obtained by an experiment and an adsorption force reduction rate.
FIG. 10 is a diagram corresponding to FIG.
FIG. 11 is a diagram corresponding to FIG.
[Explanation of symbols]
1 Injection molding machine
2 Fixed platen
2a Fixed mold
2c board
3 Movable platen
3a Movable mold
10 Mold adsorption fixing device
11 Plate member
12, 42, 52 Block member
12a, 42a, 52a Mold fixing surface
13 Magnetic generation and retention mechanism
30, 40, 50 Magnetic force retaining member
31 Coil spring
32 bolt (locking member)
41, 51 Belleville spring

Claims (6)

A plate member, a plurality of magnetic block members fixed to the plate member having a fixing surface for fixing the object to be fixed, and a magnetic force for attracting and fixing the object to be fixed to the fixing surface are generated. together can hold, a magnetic attraction holding device that includes a magnetic force generation holding mechanism to act on the fixed element via a plurality of block members the magnetic force,
The magnetic force generation and holding mechanism includes a plurality of permanent magnets disposed around the plurality of block members, a plurality of alnico magnets disposed on the opposite side of the fixed surface with respect to the plurality of block members, and a plurality of A plurality of coils wound around each of the Alnico magnets,
Wherein each block member, Rutotomoni provided a magnetic force holding member partially protruding possible magnetic steel from and fixed surface can move forward and backward in a direction perpendicular to the fixed surface, than the magnetic force holding member a predetermined projected position A locking member for locking so as not to protrude is fixedly provided on the block member,
The magnetic force holding member constitutes a magnetic path through which a part of the magnetic flux generated by the magnetic force generation and holding mechanism passes by being attracted to the fixed body when the fixed body is fixed to the fixed surface. When separated from the fixed surface, it is configured to hold the state adsorbed to the fixed body within the range of a predetermined separation distance.
A magnetic adsorption holding device characterized by that.   2. The magnetism according to claim 1, wherein a magnetic path is formed between the fixed body and the block member via the magnetic force holding member while the magnetic force holding member is attracted to the fixed body. Adsorption holding device. A plate member fixed to the surface of the mold fixing plate and a plurality of magnetic blocks having a mold fixing surface and fixed to the plate member for fixing the die to the mold fixing plate of the injection molding machine. A member and a magnetic force generating and holding mechanism capable of generating a magnetic force for attracting the mold to the mold fixing surface and holding the magnetic force and acting the magnetic force on the mold through a plurality of block members are provided. A magnetic adsorption holding device,
The magnetic force generation and holding mechanism includes a plurality of permanent magnets disposed around the plurality of block members, and a plurality of alnico magnets disposed on the opposite side of the mold fixing surface with respect to the plurality of block members. A plurality of coils each wound around a plurality of alnico magnets,
Wherein each block member, predetermined Rutotomoni, the magnetic force holding member partially disposed magnetic force holding member made extendable magnetic material from and die fastening surface can move forward and backward in a direction perpendicular to the die fastening surface A locking member for locking so as not to protrude from the protruding position of is fixedly provided on the block member,
The magnetic force holding member constitutes a magnetic path through which a part of the magnetic flux generated by the magnetic force generation and holding mechanism passes by being attracted to the mold when the mold is fixed to the mold fixing surface. When separating from the mold fixing surface, it is configured to hold the state adsorbed to the mold within a predetermined separation distance range,
A magnetic adsorption holding device characterized by that.   The magnetic adsorption / holding according to claim 3, wherein a magnetic path is formed between the mold and the block member via the magnetic force holding member while the magnetic force holding member is adsorbed to the mold. apparatus.   The magnetic adsorption holding device according to any one of claims 1 to 4, wherein each block member is provided with a biasing member that biases the magnetic force holding member toward the protruding side.   The magnetic attraction / holding device according to claim 1, wherein each block member is provided with a plurality of magnetic force holding members.

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