JP2019051622A - Mold platen fall prevention device for vertical injection molding machine - Google Patents

Abstract

To provide a mold platen fall prevention device for a vertical injection molding machine, which is low in maintenance and manufacturing cost.SOLUTION: In a vertical injection molding machine equipped with a toggle mechanism, a ball screw is rotated by a large pulley provided on a lower movable plate to drive the toggle mechanism, and a die is opened and closed. A stopper plate 31 composed of a stopper plate base part 37 rotatably supported on a lower movable plate, and a stopper piece 38 having a plurality of projections 39 exchangeably provided on the stopper plate base part is provided in the vicinity of the large pulley. The plurality of projections 39 are engaged with teeth of a gear of the large pulley by pressing the stopper plate 31 against the large pulley by an actuator 32 to prevent a mold plate from falling.SELECTED DRAWING: Figure 3

Description

  The present invention is provided at a fixed platen, a plurality of tie bars vertically penetrating through the fixed platen, an upper movable plate fixed to an upper end portion of the tie bar, and a lower end portion of the tie bar. In a vertical injection molding machine, which is composed of a lower movable plate and a toggle mechanism provided between the fixed plate and the lower movable plate, the mold is opened and closed when the toggle mechanism crosshead is driven. The present invention relates to a mold platen fall prevention device for preventing a movable platen from falling.

  A vertical injection molding machine that is opened and closed by a toggle mechanism is well known, and is fixed to a fixed platen, a plurality of tie bars that pass vertically through the fixed platen, and an upper end of the tie bar. The upper movable platen, the lower movable platen provided at the lower end of the tie bar, and the toggle mechanism provided between the fixed platen and the lower movable platen. The crosshead of the toggle mechanism is driven by a ball screw mechanism. For example, the crosshead is as follows. A ball nut is provided integrally with the cross head, and a ball screw is screwed to the ball nut. A large pulley is fixed to the lower end of the ball screw. On the other hand, the lower movable plate is provided with a mold opening / closing servo motor, and this server motor is provided with a drive pulley. The driving pulley and the large pulley are wound around by the timing belt. Accordingly, when the mold opening / closing servo motor is driven, the rotational force is transmitted to the drive pulley, the timing belt, and the large pulley, and the ball screw rotates. Then, the cross head moves up and down together with the ball nut, and the toggle mechanism is driven, thereby driving the vertical movable plate up and down. That is, the mold is opened and closed.

  In the conventional vertical injection molding machine, the mold opening / closing servo motor is equipped with a brake, and when the servo motor stops, the rotation of the servo motor is restricted by the brake. The position is held. That is, the mold plate is prevented from falling. However, even if the servomotor is stopped, if the timing belt is cut, it is not possible to prevent the mold plate from falling. In other words, safety cannot be ensured. On the other hand, Patent Document 1 proposes a pattern board fall prevention device that can reliably prevent the mold board from dropping even when the timing belt is cut.

JP 2008-105185 A

  The platen fall prevention device described in Patent Document 1 includes a stopper made of a predetermined plate in the vicinity of a large pulley. The stopper is pivotally supported by a pin and is driven by an actuator such as an air cylinder. A plurality of protrusions are formed on the stopper, and when the stopper is pressed against the large pulley by the actuator, it meshes with the gear teeth of the large pulley, thereby restricting the rotation of the large pulley and preventing the mold plate from falling. It has become. The pin that supports the stopper is in mesh with the protrusion of the stopper and the gear teeth of the large pulley, and when the protrusion receives force from the gear teeth of the large pulley to be rotated, It is generally located in the direction. Therefore, when the rotation of the large pulley is restricted by the stopper, most of the force acting on the stopper acts on the pin, and no load is imposed on the actuator that drives the stopper. Thereby, the rotation of the large pulley can be safely stopped.

  The platen fall prevention device described in Patent Document 1 includes a stopper having a predetermined protrusion that meshes with the gear teeth of the large pulley, and the rotation of the large pulley is regulated only by driving the stopper. Even if it occurs, it is possible to reliably prevent the vertical movable plate from falling. Further, since the rotation of the large pulley is regulated by the meshing between the gear teeth and the protrusions, the rotation can be regulated reliably unlike an apparatus that regulates the rotation of an electromagnetic clutch or the like, which is highly reliable and excellent. However, there are also problems to be solved for the platen fall prevention device. First, there is a maintenance problem. The stopper projections are worn a little each time they mesh with the gear teeth of the large pulley and need to be replaced after a long period of use. In the case of replacement, the entire apparatus including the stopper and the actuator that drives the stopper must be replaced. This is costly. Alternatively, it is conceivable to replace only the stopper instead of the entire apparatus. However, when replacing only the stopper, remove the pin that pivots the stopper, disconnect the actuator, remove the old stopper, replace it with a new stopper, pivot it again with the pin, and reconnect the actuator. There must be. That is, the amount of work is large and the cost of maintenance increases. There is also a problem of manufacturing cost. The plurality of protrusions formed on the stopper are formed at the same pitch as the gear teeth so as to properly mesh with the gear teeth of the large pulley. If the type of vertical injection molding machine changes, the pitch of the gear teeth of the large pulley may change, but if the pitch changes, it is necessary to change the interval between the plurality of protrusions of the stopper accordingly. Then, since the shape of the stopper has to be changed for each vertical injection molding machine, the manufacturing cost of the mold platen fall prevention device increases.

  It is an object of the present invention to provide a platen drop prevention device for a vertical injection molding machine that solves the above-described problems. Specifically, the platen can be reliably dropped by cutting a timing belt or the like. It is an object of the present invention to provide a platen drop prevention device for a vertical injection molding machine, which can prevent the above-mentioned problem, has a low maintenance cost, and has a low manufacturing cost.

  In order to achieve the above object, the present invention is directed to a platen drop prevention device for a vertical injection molding machine in which a vertically movable platen is driven by a toggle mechanism with respect to a fixed platen. The toggle mechanism is driven by a cross head driven by a ball screw mechanism rotated by a large pulley provided in the lower movable plate. The platen fall prevention device includes a predetermined stopper plate. The stopper plate has a plurality of protrusions and is pivotally supported on the lower movable plate in the vicinity of the large pulley. When driven by a predetermined actuator, the protrusion of the stopper plate meshes with the gear teeth of the large pulley to restrict the rotation of the large pulley, thereby preventing the mold plate from falling. In the present invention, the stopper plate includes a stopper plate base portion and a stopper small piece attached to the stopper plate base portion. A step plate is formed on the stopper plate base, and the small stopper piece is attached to this step. Two side wall surfaces adjacent to each other are formed on the stepped portion, and the stopper small piece is attached so that the two side surfaces are in contact with these side wall surfaces. The angle formed by the two adjacent side wall surfaces is an acute angle.

Thus, in order to achieve the above object, the invention according to claim 1 is fixed to a fixed platen, a plurality of tie bars vertically penetrating through the fixed platen, and an upper end portion of the tie bar. An upper movable platen, a lower movable plate provided at the lower end of the tie bar, and a toggle mechanism provided between the fixed platen and the lower movable plate, and the crosshead of the toggle mechanism includes the lower movable platen. It is driven by a ball screw mechanism that is rotated by a large pulley provided on the belt. When the large pulley is rotated through a predetermined timing belt, the crosshead is driven to open and close the mold. In the vertical injection molding machine, it is a mold plate fall prevention device for restricting the rotation of the large pulley to prevent the vertical movable plate from falling, the mold plate fall prevention device comprising a stopper plate, The stopper plate includes a plurality of protrusions and is pivotally supported with respect to the lower movable plate in the vicinity of the large pulley. When the stopper plate is pressed against the large pulley by a predetermined actuator, A plurality of protrusions mesh with a plurality of teeth of the gear of the large pulley to restrict the rotation of the large pulley, and the stopper plate is a stopper plate base that is pivotally supported by the lower movable platen And a stopper small piece that is replaceably attached to the stopper plate base, and the plurality of protrusions are formed on the stopper small piece. It is configured as a machine platen fall prevention device.
According to a second aspect of the present invention, in the platen fall prevention device according to the first aspect, a stepped portion having a predetermined shape is formed on the stopper plate base portion, and the stopper small piece is placed in the stepped portion and The stopper small piece body is fixed in a state where the side surface of the stopper small piece is in contact with the side wall surface forming the step portion, and is configured as a platen drop prevention device for a vertical injection molding machine.
According to a third aspect of the present invention, in the platen fall prevention device according to the second aspect, the stepped portion has two adjacent side wall surfaces, and the stopper small piece has two adjacent side surfaces. A platen drop prevention device for a vertical injection molding machine characterized in that the two side wall surfaces are fixed in contact with the two flat side wall surfaces, and the angle formed by the two side wall surfaces is an acute angle. Composed.
According to a fourth aspect of the present invention, there is provided the mold plate drop prevention device according to the third aspect, wherein a notch is formed in a joint portion between the two side wall surfaces. It is configured as a machine platen fall prevention device.

  According to the above, the present invention is configured as a platen fall prevention device for a vertical injection molding machine. The vertical injection molding machine includes a fixed platen and a vertical movable platen, and the vertical movable platen is driven by a toggle mechanism to open and close the mold. The toggle mechanism is driven by a cross head driven by a ball screw mechanism rotated by a large pulley provided in the lower movable plate. The mold platen fall prevention device of the present invention includes a stopper plate that is pivotally supported in the vicinity of the large pulley in the lower movable platen. When the stopper plate is pressed against the large pulley by a predetermined actuator, the plurality of protrusions formed on the stopper plate are engaged with the gear teeth of the large pulley, thereby restricting the rotation of the large pulley. That is, even if a problem such as cutting of the timing belt occurs, the rotation of the large pulley can be reliably restricted to prevent the mold plate from falling. In the present invention, the stopper plate is composed of a stopper plate base portion pivotally supported by the lower movable platen, and a stopper small piece attached to the stopper plate base portion in an exchangeable manner. The protrusion is formed on the stopper small piece. Therefore, even if a plurality of protrusions wear due to long-term use, only the stopper small piece needs to be replaced, and the cost required for maintenance is small. In addition, it is necessary to form a plurality of protrusions according to the gear teeth pitch of the large pulley. When the vertical injection molding machine changes, the large pulley changes, which may cause the gear tooth pitch to vary. However, it is possible to cope with a large pulley with any pitch tooth by simply replacing the stopper piece. That is, there is no need to prepare a platen fall prevention device for each model, and the effect of reducing the manufacturing cost can be obtained. According to another invention, the stopper plate base is formed with a stepped portion having a predetermined shape, the stopper piece is placed in the step, and the side surface of the stopper piece is in contact with the side wall surface forming the step. It is fixed with. When a plurality of protrusions of the stopper small piece mesh with the gear teeth of the large pulley to restrict the rotation of the large pulley, a predetermined moment acts on the stopper small piece. Since the side surface of the stopper small piece is in contact with the side wall surface of the step formed on the stopper plate base, the pressing force generated by the moment is received by the contact surface, preventing the stopper small piece from rotating. Will be. According to another invention, the stepped portion is formed with two adjacent side wall surfaces, and the stopper small piece is fixed in a state where the two adjacent side surfaces are in contact with the two flat side wall surfaces. The angle formed by the side wall surface is an acute angle. The stopper small piece is fixed to the stopper plate base portion with a bolt or the like. However, when the stepped portion and the stopper small piece are in contact with only one side wall surface and one side surface, The load also acts on the bolt due to the acting moment. However, according to the present invention, the stepped portion and the stopper small piece are in contact with the two adjacent side wall surfaces and the two adjacent side surfaces, and the angle formed by the two side wall surfaces is an acute angle. The moment acting on the stopper piece is almost received by the two side wall surfaces. That is, the stopper small piece can be reliably prevented from rotating, and the large pulley can be stably maintained in the stopped state. Further, the load acting on the bolt for attaching the stopper small piece can be reduced, and the reliability of the apparatus is improved.

It is a front view which shows the vertical injection molding machine which concerns on embodiment of this invention. It is a figure which shows the pattern board fall prevention apparatus which concerns on this Embodiment, and is a front view of the mold board fall prevention apparatus seen from the back surface of the lower movable board. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the pattern board fall prevention apparatus which concerns on this Embodiment, The (a) is a front view which shows a pattern board fall prevention apparatus, The (a) is expanded a part of stopper plate containing a stopper small piece body. The front view to show, (c) is sectional drawing of the stopper plate which shows the cross section cut | disconnected by XX in (b). It is a figure explaining the effect | action of the pattern board fall prevention apparatus which concerns on this Embodiment, The (a), (b) is a front view of a stopper plate which shows a state when a moment acts on a stopper small piece body. .

  Embodiments of the present invention will be described below. A vertical injection molding machine 1 according to the present embodiment is configured in the same manner as a conventional vertical injection molding machine as shown in FIG. That is, the vertical injection molding machine 1 includes a fixed platen 3 fixed to a predetermined housing (not shown), and a plurality of tie bars 4, 4, which slidably penetrate the fixed platen 3 vertically. ..., an upper movable board 6 fixed to the upper ends of the tie bars 4, 4, ..., a lower movable board 7 provided at the lower ends of the tie bars 4, 4, ..., the fixed board 3, and the lower movable board. 7 and a toggle mechanism 9 provided between the two. The toggle mechanism 9 is driven by a ball screw mechanism 11. A ball nut 12 of the ball screw mechanism 11 is fixed to a cross head 13 of the toggle mechanism 9, and a ball screw 15 is screwed to the ball nut 12. The ball screw 15 penetrates the lower movable platen 7 and its lower end is fixed to a large pulley 17 provided on the lower surface side of the lower movable platen 7. When the large pulley 17 is rotated, the ball screw 15 is rotated. A mold opening / closing motor 19 and a driving pulley 20 are provided on the side of the lower movable platen 7. The driving pulley 20 and the large pulley 17 are wound around a timing belt 22. In such a vertical injection molding machine 1 according to the present embodiment, a fixed mold 24 is provided on the fixed plate 3, a movable mold 25 is provided on the upper movable plate 6, and Although not shown in the figure, an injection device is provided. When the mold opening / closing motor 19 is driven in the vertical injection molding machine 1, the large pulley 17 and the ball screw 15 rotate via the drive pulley 20 and the timing belt 22, and the cross head 13 moves up and down together with the ball nut 12 to toggle the mechanism 9. Is driven, and the upper and lower movable boards 6 and 7 are moved up and down. That is, the mold is opened and closed.

  The mold platen fall prevention device 27 according to the present embodiment is provided in the vicinity of the large pulley 17 on the lower surface side of the lower movable platen 7. FIG. 2 is a view of the lower movable platen 7 as viewed from the bottom. The mold platen dropping device 27 is relatively narrow in the lower movable platen 7 surrounded by the timing belt 22 between the drive pulley 20 and the large pulley 17. It is provided in the part. The mold platen fall prevention device 27 includes a mounting plate 28 fixed to the back surface of the lower movable platen 7, a stopper plate 31 pivotally supported by a pin 29 with respect to the mounting plate 28, and a stopper plate. An actuator for driving 31, that is, an air cylinder 32 is configured. It can also be said that the stopper plate 31 is pivotally supported with respect to the lower movable platen 7.

  FIG. 3 shows an enlarged view of the platen fall prevention device 27 according to the present embodiment. The tip of the piston 33 of the air cylinder 32 and the stopper plate 31 are pivotally attached by a pin 35, and when the air cylinder 32 is driven, the stopper plate 31 rotates around the pin 29 within a predetermined range as indicated by reference numeral 36. Move.

  The pattern board fall prevention device 27 according to the present embodiment is characterized in that the stopper plate 31 is composed of two members. That is, the stopper plate 31 includes a stopper plate base portion 37 as a main body and a stopper small piece 38 attached to the stopper plate base portion 37. The stopper small body 38 has an elongated rectangular shape on the upper surface, and a plurality of protrusions 39, 39,... Are formed on a portion corresponding to one long side. As shown in FIG. 3C, the stopper plate base portion 37 is formed to have a thin wall by cutting an edge portion within a predetermined range. That is, the step part 40 is formed. A stopper small piece 38 is attached to the stepped portion 40. Incidentally, in order to form the stepped portion 40, the stopper plate base portion 37 is formed with two adjacent side wall surfaces 42 and 43. The side surface 44 corresponding to the long side of the stopper small piece 38 and the side surface 45 corresponding to the short side are in contact with the two side wall surfaces 42 and 43, respectively. The stopper small piece 38 is fixed to the stopper plate base portion 37 by bolts 47 in a state in which they abut. Thus, since the stopper plate 31 is composed of two members, it can be easily replaced if the stopper small piece 38 deteriorates due to wear or the like.

  In the present embodiment, the angle α formed by the two side wall surfaces 42 and 43 of the stepped portion 40 of the stopper plate base portion 37, that is, the angle α formed by the side surfaces 44 and 45 of the stopper small piece 38 is also characteristic. . This angle α is an acute angle smaller than 90 degrees. Since it has an acute angle, the stopper small piece 38 is firmly held by the two side wall surfaces 42 and 43 so that even if a moment acts on the stopper small piece 38, the stopper small piece 38 does not rotate. . In the stopper plate base portion 37, a notch 48 is formed in a joint portion between the two adjacent side wall portions 42 and 43 to prevent breakage due to stress concentration.

  In the pattern board fall prevention device 27 according to the present embodiment, when the air cylinder 32 is driven, the stopper plate 31 is pressed against the large pulley 17. Gear teeth are formed on the large pulley 17, and a plurality of protrusions 39, 39,... Of the stopper small piece 38 mesh with these teeth. When engaged, the rotation of the large pulley 17 is restricted, thereby preventing the vertically movable plates 6 and 7 from falling. By the way, when the rotation of the large pulley 17 is restricted by the stopper plate 31, if a rotational force is applied to the large pulley 17, the stopper small piece 38 is shown in FIGS. 4A and 4B depending on the direction of rotation. As shown, any one of the moments 49 and 50 acts. When a moment in the rotational direction indicated by reference numeral 49 acts, a pressing force acts between the side wall portion 42 of the stopper plate base portion 37 and the side surface 44 of the stopper small piece body 38 at the location indicated by reference numeral 52. This cancels out the moment. On the other hand, when a moment in the rotational direction indicated by reference numeral 50 is applied, a pressing force is applied between the side wall portion 42 of the stopper plate base portion 37 and the side surface 44 of the stopper small piece 38 at the location indicated by reference numeral 53. A pressing force is applied between the side wall portion 43 of the stopper plate base portion 37 and the side surface 45 of the stopper small piece 38 at the location indicated by reference numeral 54. These cancel out the moment. Since the moments in any of the rotational directions indicated by reference numerals 49 and 50 are canceled, the stopper small piece body 38 can be stably controlled without rotating.

DESCRIPTION OF SYMBOLS 1 Vertical injection molding machine 3 Fixed board 4 Tie bar 6 Upper movable board 7 Lower movable board 9 Toggle mechanism 11 Ball screw mechanism 12 Ball nut 13 Cross head 15 Ball screw 17 Large pulley 19 Type opening / closing motor 22 Timing belt 27 Mold plate fall prevention device 29 Pin 31 Stopper plate 32 Air cylinder 37 Stopper plate base 38 Stopper small piece 39 Projection 40 Step 42 Side wall surface 43 Side wall surface 44 Side surface 45 Side surface 48 Notch

Claims (4)

A fixed plate, a plurality of tie bars vertically penetrating the fixed plate, an upper movable plate fixed to the upper end of the tie bar, and a lower movable plate provided at the lower end of the tie bar And a toggle mechanism provided between the fixed platen and the lower movable platen, and the crosshead of the toggle mechanism is driven by a ball screw mechanism rotated by a large pulley provided on the lower movable platen. In a vertical injection molding machine in which the crosshead is driven to open and close the mold when the large pulley is rotated through a predetermined timing belt, the rotation of the large pulley is restricted. A platen fall prevention device that prevents the vertical movable plate from falling,
The mold plate fall prevention device includes a stopper plate, the stopper plate includes a plurality of protrusions and is pivotally supported with respect to the lower movable plate in the vicinity of the large pulley. When the stopper plate is pressed against the large pulley by an actuator, the plurality of protrusions mesh with a plurality of teeth of the gear of the large pulley, and the rotation of the large pulley is restricted,
The stopper plate includes a stopper plate base portion pivotally supported by the lower movable plate, and a stopper small piece attached to the stopper plate base portion so as to be replaceable. A platen fall prevention device for a vertical injection molding machine, characterized in that it is formed on a small stopper piece.   2. The mold platen fall prevention device according to claim 1, wherein a stepped portion having a predetermined shape is formed in the stopper plate base portion, the stopper small piece is placed in the stepped portion, and a side surface of the stopper small piece is the stepped portion. A platen drop prevention device for a vertical injection molding machine, characterized in that it is fixed in a state of being in contact with a side wall surface that forms a wall.   3. The mold platen fall prevention device according to claim 2, wherein the stepped portion is formed with two adjacent side wall surfaces, and the stopper small piece has two adjacent side surfaces in contact with the two flat side wall surfaces. A platen drop prevention device for a vertical injection molding machine, characterized in that the angle formed by the two side wall surfaces is an acute angle.   4. The platen drop prevention device according to claim 3, wherein a notch is formed in a joint portion between the two side wall surfaces.

Images