JP2018027656A - Molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding machine with an eject device excellent in operability and durability.SOLUTION: The eject device 6 comprises: a ball screw mechanism composed of a nut body 42 held freely rotatively to a movement die plate 14 and a screw shaft 43 screwed in the nut body 42; an electrically driven servomotor 70 for eject mounted in the movement die plate 14; and a pulley 57 fitted to the nut body 42 and transferring the driving force of the electrically driven servomotor 70 for eject to the nut body 42. A ball circulation passage 46 of the ball screw mechanism is formed at the nut body 42, and the pulley 47 is fitted to the central part of the ball circulation passage 46.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a molding machine such as an injection molding machine and a die casting machine, and more particularly to an ejecting apparatus for taking out a molded product from a mold apparatus.

  A molding machine such as an injection molding machine or a die casting machine is provided with an ejecting device for taking out a molded product from a mold device (for example, see Patent Document 1). 5 and 6 show a conventionally known ejector of a molding machine. FIG. 5 is an enlarged view of a main part of a molding machine according to a conventional example, and FIG.

  5 and 6, reference numeral 101 denotes a moving die plate, reference numeral 102 denotes an ejecting device attached to the moving die plate 101, and reference numeral 103 denotes a connecting pin between the moving die plate 101 and a tail stock (not shown). Figure 2 shows a toggle link mechanism linked together. Each of these drawings shows a state in which the toggle link mechanism 103 is contracted, a mold apparatus (not shown) is in the mold open state, and the eject apparatus 102 is in a standby position before taking out the molded product.

  The ejecting device 102 includes a nut body 105 that is rotatably held by the movable die plate 101 via a bearing 104 that is a combination of a plurality of bearings, a screw shaft 106 that is screwed into the nut body 105, and a screw shaft 106. The eject plate 107 is connected to one end, and a plurality of eject pins 108 are fixed to the eject plate 107 at one end.

  As shown in an enlarged view in FIG. 6, the nut body 105 is formed in a cylindrical shape in which a screw hole 111 and a straight hole 112 having a larger diameter than the screw hole 111 are formed coaxially in the center of the cross section. A screw shaft 106 is screwed into the screw hole 111. The screw hole 111 is formed over the length of about ½ of the entire length of the nut body 105. The straight hole 112 is formed to have a diameter through which the screw shaft 106 can be inserted.

  The outer shape of the nut body 105 will be described. A ring-shaped flange 113 projects outwardly at a substantially central portion in the length direction of the nut body 105, and on the right side of the formation portion of the flange 113 in the drawing. Is the holding portion 114 of the nut body 105, and the pulley mounting portion 115 is on the left side. The pulley 117 is attached to the pulley mounting portion 115 and is fixed to the nut body 105 with a bolt 119. As a result, the pulley 117 according to the conventional example is disposed close to the side surface portion of the flange 113.

  The moving die plate 101 is formed with a nut body housing recess 121 and a screw shaft insertion hole 122.

  The nut body 105 is rotatably held by the movable die plate 101 via the bearing 104 by housing the holding portion 114 to which the bearing 104 is mounted in a nut body housing recess 121 formed in the movable die plate 101. The The holding portion 114 is pushed into the nut body accommodating recess 121 until the side surface of the flange 113 hits the end surface of the movable die plate 101. The holding part 114 pushed into the nut body housing recess 121 is prevented from falling off by the drop-off preventing member 124 attached to the movable die plate 101 using the bolt 123.

  A timing belt (not shown) is wound around the pulley 117, and is driven to rotate by an electric servo motor for ejection (not shown) provided on the movable die plate 101.

  Since the molding machine according to the conventional example is configured as described above, when an unillustrated electric servomotor for rotation is rotationally driven in a predetermined direction, the nut body 105 is set to a predetermined via a timing belt and a pulley 117 (not illustrated). The screw shaft 106 and the eject plate 107 are linearly driven in a predetermined direction as the nut body 105 rotates.

  When the eject plate 107 is linearly driven in a direction approaching the movable die plate 101, the tip of the eject pin 108 protrudes from the end surface of the movable die plate 101, and the molded product is taken out. On the other hand, when the eject plate 107 is linearly driven in a direction away from the movable die plate 101, the tip of the eject pin 108 is accommodated in the movable die plate 101 so that the next molding operation can be performed. Become.

JP2015-128874A

  By the way, in a ball screw mechanism comprising a nut body 105 in which a small-diameter screw hole 111 and a large-diameter straight hole 112 are formed concentrically at the center of the cross section, and a screw shaft 106 screwed into the screw hole 111. The ball circulation path 120 constituting the ball screw mechanism is formed inside the pulley mounting portion 115 inevitably formed with the screw hole 111.

  However, in the conventional molding machine, as shown in FIGS. 5 and 6, the pulley 117 that transmits the driving force of the electric servomotor for ejection to the nut body 105 is attached to the end of the pulley attachment portion 115. As the pulley 117 is driven to rotate, a large strain acts on the nut body 105, and the strain acting on the nut body 105 acts unbalanced on the ball circulation path 120. For this reason, in the conventional molding machine, there is a problem that the ejecting device 102 is difficult to operate smoothly, and as a result, the durability of the ejecting device 102 is also impaired, and there is room for improvement in this respect.

  The present invention has been made to solve such problems of the prior art, and an object of the present invention is to provide a molding machine equipped with an ejecting device excellent in operability and durability.

  In order to solve the above-mentioned problems, the present invention provides a mold clamping unit having a movable die plate, an injection unit for injecting and filling a molding material into a cavity of a mold apparatus clamped by the mold clamping unit, In a molding machine including an ejecting device for removing a molded product from the mold device, the ejecting device includes a nut body rotatably held by the movable die plate and a screw shaft screwed to the nut body. A ball screw mechanism that is mounted on the movable die plate, and a pulley that is attached to the nut body and transmits a driving force of the electric servo motor for ejection to the nut body. The nut body forms a ball circulation path of the ball screw mechanism, and the pulley is attached to a central portion of the ball circulation path. Vignetting wherein the are.

  According to this configuration, since the pulley is attached to the central portion of the ball circulation path, the distortion of the nut body due to the rotational driving of the pulley is reduced, and the distortion acts equally on the ball circulation path. Therefore, the operability and durability of the eject device are improved.

  In the molding machine having the above-described configuration, the nut body may be formed with a ring-shaped flange at a central portion in a length direction, and a bearing may be attached to one side of the nut body via the flange. The ball circulation path is formed on the other side of the nut body via a flange, the flange and the bearing are accommodated in a nut body housing recess formed in the movable die plate, and the nut body is The movable die plate is rotatably held via the bearing.

  According to this configuration, since the flange and the bearing are accommodated in the nut body accommodating recess formed in the movable die plate, the ejecting device from the end surface of the movable die plate is compared with the case where the flange is abutted against the end surface of the movable die plate Can be reduced, and the molding machine can be downsized.

  According to the present invention, it is possible to improve the operability and durability of the ejecting device provided in the molding machine, and to reduce the size of the molding machine.

It is a block diagram of the molding machine which concerns on embodiment. It is the front view seen from the tail stock side of the movement die plate with which the molding machine concerning an embodiment is equipped. It is principal part sectional drawing of the molding machine which concerns on embodiment. It is the A section enlarged view of FIG. It is principal part sectional drawing of the molding machine which concerns on a prior art example. It is the B section enlarged view of FIG.

  Hereinafter, the molding machine according to the embodiment will be described taking an injection molding machine as an example. Note that the scope of the present invention is not limited to the embodiments described below, and it goes without saying that various design changes can be made without departing from the spirit of the present invention.

  As shown in FIG. 1, the molding machine 1 of this example is an injection molding machine, and includes a machine base 2, a mold clamping unit 3, an injection unit 4, a mold device 5, an ejection device 6, and these A display device 7 for displaying the operation state of the mold clamping unit 3, the injection unit 4 and the ejection device 6, and a control device 8 for controlling the driving of the mold clamping unit 3, the injection unit 4, the ejection device 6 and the display device 7. Have.

  The mold clamping unit 3 includes a fixed die plate 11, a tail stock 12 disposed so as to face the fixed die plate 11, and a plurality of tie bars 13 bridged at both ends by the fixed die plate 11 and the tail stock 12. , And a movable die plate 14 that is guided by the tie bar 13 and moves between the fixed die plate 11 and the tail stock 12. The fixed die plate 11 is fixed at a predetermined position on the upper surface of the machine base 2. On the other hand, the tailstock 12 is movably attached to the upper surface of the machine base 2 within a range in which the mold thickness can be adjusted, and is fixed to the upper surface of the machine base 2 after the mold thickness adjustment.

  A fixed die 15 constituting the mold apparatus 5 is attached to a surface of the fixed die plate 11 facing the moving die plate 14, and a mold is mounted on the surface of the moving die plate 14 facing the fixed die plate 11. A moving mold 16 constituting the device 5 is attached. Between the mating surface 15a of the fixed mold 15 and the mating surface 16a of the movable mold 16, a cavity 17 having a predetermined shape is formed when the mold is clamped.

  The moving die plate 14 is moved in the mold opening direction or the mold closing / clamping direction by driving the toggle link mechanism 20 having both ends connected to the tail stock 12 and the moving die plate 14 to contract or extend.

  That is, both ends of the link member constituting the toggle link mechanism 20 are connected to the tail stock 12 and the movable die plate 14 via the connection pins 21 and 22, respectively. Further, the straight head portion 19 of the ball screw mechanism is connected to the cross head 23 of the toggle link mechanism 20. The rectilinear portion 19 of the ball screw mechanism is screwed into a rotating portion of a ball screw mechanism (not shown), and the rotating portion of the ball screw mechanism is rotationally driven using a mold opening / closing electric servo motor (not shown). In the example of FIG. 1, a screw shaft is used as the rectilinear portion 19 of the ball screw mechanism. However, a nut body screwed to the screw shaft may be used as the rectilinear portion 19 of the ball screw mechanism. .

  Therefore, when the mold opening / closing electric servomotor is driven and the toggle link mechanism 20 is extended with the tailstock 12 fixed to the machine base 2, the movable die plate 14 is guided to the tie bar 13 and moved to the fixed die plate side. Then, mold closing and subsequent mold clamping are performed. On the other hand, when the mold opening / closing electric servomotor is driven and the toggle link mechanism 20 is contracted while the tailstock 12 is fixed to the machine base 2, the movable die plate 14 is guided by the tie bar 13 toward the tailstock 12 side. Move and mold open.

  As shown in FIG. 1, the injection unit 4 includes a cylindrical heating cylinder 32 having an injection nozzle 33 attached to the tip thereof, a screw 34 housed in the heating cylinder 32 so as to be rotatable and movable back and forth, and a raw material A hopper 35 for charging the resin and a hopper block 31 for supplying the raw resin charged in the hopper 35 into the heating cylinder 32 are provided. A band heater 36 that heats the resin supplied into the heating cylinder 32 is wound around the outer periphery of the heating cylinder 32.

  The injection unit 4 includes a metering electric servo motor and an injection electric servo motor (not shown), and transmits the power of each motor to the screw 34 via a required power transmission mechanism.

  The electric metering servomotor rotates the screw 34 in one direction. When the screw 34 is rotationally driven in accordance with a command from the control device 8, the raw material resin put into the hopper 35 falls into a screw groove formed in the screw 34 by its own weight and is introduced into the heating cylinder 32. The The raw material resin introduced into the heating cylinder 32 is melted by frictional heat and shearing heat generated by the rotational drive of the screw 34, and heat generated by the band heater 36, and is sequentially attached to the tip of the heating cylinder 32. It is transferred to the nozzle 33 side.

  The electric servomotor for injection drives the screw 34 to move straight forward or backward. When a predetermined amount of molten resin is stored at the tip of the heating cylinder 32, the electric servomotor for injection is activated in response to a command from the control device 8, and the screw 34 is driven forward to move to the tip of the heating cylinder 32. A predetermined amount of the molten resin stored is injected and filled from the injection nozzle 33 into the cavity 17 of the mold apparatus 5. Thereby, a molded product having a predetermined shape is obtained.

  As shown in FIG. 1, the display device 7 is disposed at a position where the operator on the front surface of the machine base 2 can easily see. The display device 7 can be provided with an input device 7a. The control device 8 is installed inside the machine base 2. The display device 7 lists detection data of various sensors (not shown) provided in the mold clamping unit 3, the injection unit 4, and the ejection device 6, and calculation data of the control device 8 based on these detection values. It can be displayed in a desired format such as display or graph display.

  The control device 8 controls the entire control of the molding machine 1 including the mold clamping unit 3, the injection unit 4, the eject device 6 and the display device 7.

  Hereinafter, the ejecting apparatus 6 of the molding machine according to the embodiment will be described in detail with reference to FIGS.

  As shown in FIGS. 2 to 4, the ejecting apparatus 6 according to the embodiment is also the same in basic structure as the ejecting apparatus 102 according to the conventional example shown in FIGS. It is attached to a movable die plate 14 that is moved in the mold opening direction and the mold closing / clamping direction. 3 and 4, the toggle link mechanism 20 is contracted, the fixed mold 15 and the movable mold 16 are in the mold open state, and the ejecting device 6 is in the standby position before taking out the molded product. Is shown.

  As shown in FIGS. 3 and 4, the ejecting apparatus 6 according to the embodiment includes a nut body 42 that is rotatably held by the movable die plate 14 via a bearing 41 that is a combination of a plurality of bearings, and a nut body 42. The screw shaft 43 is engaged with the screw shaft 43, the eject plate 44 is connected to one end of the screw shaft 43, and the plurality of eject pins 45 are fixed to the eject plate 44 at one end.

  As shown in an enlarged view in FIG. 4, the nut body 42 is formed in a cylindrical shape in which a screw hole 51 and a straight hole 52 having a larger diameter than the screw hole 51 are formed coaxially in the center of the cross section. A screw shaft 43 is screwed into the hole 51. The screw hole 51 is formed over the length of about ½ of the entire length of the nut body 42. The straight hole 52 is formed to have a diameter through which the screw shaft 43 can be inserted. In the nut body 42 of this configuration, a ball circulation path 46 of the ball screw mechanism is formed at a portion corresponding to the screw hole 51 as shown in FIG.

  A ring-shaped flange 53 projects outwardly at a substantially central portion of the nut body 42 in the length direction. In the figure, the right side of the formation portion of the flange 53 is the holding portion 54 of the nut body 42 and the left side. Is a pulley mounting portion 55. The pulley 57 is attached to the pulley mounting portion 55 and is fixed to the nut body 42 with a bolt 59. Thereby, the pulley 57 according to the embodiment is disposed at a substantially central portion of the pulley mounting portion 55, that is, a substantially central portion of the ball circulation path 46.

  As shown in FIGS. 3 and 4, the moving die plate 14 has a nut body housing recess 60 and a screw shaft insertion hole 61 formed coaxially, and the nut body 42 is rotatable in the nut body housing recess 60. Is retained.

  In the present embodiment, the holding portion 54 of the nut body 42, the flange 53, and a part of the pulley mounting portion 55 are accommodated in the nut body accommodating recess 60 formed in the movable die plate 14. Thereby, the nut body 42 is rotatably held by the movable die plate 14 via the bearing 41. The pushing position of the nut body 42 into the nut body housing recess 60 is set to a predetermined position where the pulley 47 does not interfere with the moving die plate 14. The nut body 42 pushed into the nut body housing recess 60 is prevented from falling off by the drop-off preventing member 63 attached to the movable die plate 14 using the bolts 62.

  As shown in FIG. 2, an electric servomotor 70 for ejection is mounted on the moving die plate 14, and a pulley 71 attached to the main shaft of the electric servomotor 70 for ejection and a pulley attachment portion 55 of the nut body 42. A timing belt 72 is wound around the pulley 57 attached to the belt. Accordingly, the nut body 42 is rotationally driven in a predetermined direction by the ejecting electric servo motor 70.

  Since the molding machine according to the embodiment is configured as described above, when the ejecting electric servo motor 70 is rotationally driven in a predetermined direction, the nut body 42 is set in a predetermined direction via the timing belt 72 and the pulley 57. The screw shaft 43 and the eject plate 44 are linearly driven in a predetermined direction as the nut body 42 rotates.

  When the eject plate 44 is linearly driven in a direction approaching the movable die plate 14, the tip of the eject pin 45 protrudes from the end surface of the movable die plate 14, and the molded product is taken out. On the other hand, when the eject plate 44 is linearly driven in a direction away from the movable die plate 14, the tip of the eject pin 45 is accommodated in the movable die plate 14 so that the next molding operation can be performed. Become.

  In the ejecting device 6 according to the embodiment, the pulley 57 that transmits the driving force of the ejecting electric servo motor 70 to the nut body 42 is disposed at the substantially central portion of the ball circulation path 46. The distortion of the accompanying nut body 42 can be reduced, and the distortion can be applied to the ball circulation path 46 in a balanced manner. For this reason, the ejecting apparatus 6 according to the embodiment has a smoother operation than the conventional ejecting apparatus 102, and the durability is enhanced accordingly.

  Moreover, since the ejecting apparatus 6 according to the embodiment accommodates a part of the holding portion 54, the flange 53, and the pulley mounting portion 55 of the nut body 42 in the nut body housing recess 60 formed in the movable die plate 14, Compared with the prior art in which only the holding portion 114 of the nut body 105 is accommodated in the nut body accommodating recess 121 formed in the movable die plate 101, the protruding amount of the ejecting device 6 from the movable die plate 14 can be reduced. . Therefore, as apparent from the comparison between FIG. 3 and FIG. 5, the molding machine according to the embodiment sets the protrusion amount L1 of the toggle connecting portion 14a from the movable die plate 14 to the movable die plate 101 in the molding machine according to the conventional example. Thus, the protrusion amount L2 of the toggle connecting portion 101a from can be reduced, and the molding machine can be downsized.

  In the eject device 6 according to the embodiment, the holding portion 54, the flange 53, and a part of the pulley mounting portion 55 of the nut body 42 are housed in the nut body housing recess 60 formed in the movable die plate 14. The gist of the present invention is not limited to this, and only the holding portion 54 of the nut body 42 can be accommodated in the nut body accommodating recess 60 formed in the movable die plate 14.

  In the above embodiment, the so-called return pin type ejecting device 6 has been described as an example. However, the gist of the present invention is not limited to this, and a so-called plate type ejecting device may be provided.

DESCRIPTION OF SYMBOLS 1 Molding machine 2 Machine stand 3 Clamping unit 4 Injection unit 5 Mold apparatus 6 Eject apparatus 14 Moving die plate 14a Toggle connection part 15 Fixed side mold 16 Moving side mold 20 Toggle link mechanism 41 Bearing 42 Nut body 43 Screw shaft 44 Eject plate 45 Eject pin 46 Ball circulation path 51 Screw hole 52 Straight hole 53 Flange 54 Holding portion 55 Pulley mounting portion 60 Nut body housing recess 61 Screw shaft insertion hole 70 Electric servo motor for ejection 71 Pulley 72 Timing belt

Claims (2)

A mold clamping unit having a movable die plate, an injection unit for injecting and filling a molding material into a cavity of a mold apparatus clamped by the mold clamping unit, and an ejecting apparatus for removing a molded product from the mold apparatus; In a molding machine equipped with
The ejecting device includes a ball screw mechanism including a nut body rotatably held on the moving die plate and a screw shaft screwed to the nut body, and an electric servo for ejecting mounted on the moving die plate. A motor and a pulley that is attached to the nut body and includes a pulley that transmits the drive force of the electric servomotor for ejection to the nut body;
The nut body is formed with a ball circulation path of the ball screw mechanism, and the pulley is attached to a central portion of the ball circulation path.   The nut body has a ring-shaped flange formed at the center in the length direction, a bearing is mounted on one side of the nut body via the flange, and on the other side of the nut body via the flange. The ball circulation path is formed, the flange and the bearing are accommodated in a nut body recess formed in the movable die plate, and the nut body is freely rotatable on the movable die plate via the bearing. The molding machine according to claim 1, wherein the molding machine is held by the machine.