JP2018001240A - Die lifter for press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die lifter for a press, which is built in the press, and which enables highly synchronized movement of multiple lifting members that rise and fall while supporting dies.SOLUTION: The die lifter for a press comprises: cylindrical lifting members 10 which are fitted in four circular holes 6 provided at a top surface of a bolster 3 of the press, and which rise and fall while supporting dies (an upper die and a lower die 4) upon replacement of the dies; servomotors 11 serving as drive sources of the respective lifting members 10; and motion conversion mechanisms 12 each for converting rotational motion of each servomotor 11 into elevational motion of each lifting member 10. This structure facilitates adjustment of synchronization of the lifting members 10, achieving high synchronization, and thus enabling the dies to be stably lifted straight, and to be smoothly removed from a die positioning key provided at the bolster 3, upon replacement of the dies. Consequently, damage of the die positioning key can be prevented.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a mold lifting device that lifts and lowers a mold for a press machine during replacement.

  The press machine reciprocates the slide with a predetermined lifting stroke, and works with an upper mold attached to the lower surface side of the slide and a lower die attached to the upper surface side of the bolster installed below the slide. Material) is sandwiched and processed. The upper mold and the lower mold (hereinafter, both are simply referred to as “mold”) are exchanged every time the product (molded product) produced by the press machine is changed. The procedure is as follows.

  When the press work before the mold replacement in the press machine is completed, first, the slide is lowered to the bottom dead center, and the upper mold is removed from the slide and placed on the lower mold. Then, after raising the slide, the die lifting device (die lifter) is driven to raise the plurality of lifting rollers of the die lifting device arranged on the upper surface of the bolster, and the lower die is moved by these lifting rollers. Is raised above the mold positioning key provided on the upper surface of the bolster. After that, the upper and lower molds are moved horizontally on the lifting roller and replaced with a cart that has been waiting in advance at the mold exchanging position near the press machine, and the cart is moved to the mold loading / unloading position away from the press machine. Let

  Next, the carriage on which the new mold is placed is moved to the mold exchange position, the mold is transferred from the carriage to the lifting roller, and horizontally moved to a predetermined position on the lifting roller. In this state, the mold lifting device is driven again to lower the lifting roller, and the lower mold is fitted to the mold positioning key. Then, the slide is lowered to the bottom dead center, the upper mold is attached to the slide, and the carriage returns to the mold loading / unloading position.

  Here, as the above-described mold lifting device, a hydraulic device that lifts and lowers a frame provided with lifting rollers by a plurality of hydraulic cylinders is often used (for example, see Patent Document 1).

JP 07-032070 A

  However, in the hydraulic mold lifting apparatus as described above, since the mold is lifted and lowered by a plurality of hydraulic cylinders, when the center of gravity of the mold is shifted from the center of the shape, the piston rod of each hydraulic cylinder As a result, there is a variation in the amount of movement of the mold, and the mold cannot be lifted straight (perpendicular to the top surface of the bolster), and the lower mold is caught by the mold positioning key, which may damage the mold positioning key. .

  On the other hand, it is considered that if the hydraulic cylinders are adjusted synchronously, even if the center of gravity of the mold is shifted from the center of the shape, the mold can be moved up and down straight. However, in actuality, the operation of the hydraulic cylinders is also affected by the piping path and the like, so it is not easy to synchronize the operations of the hydraulic cylinders with high accuracy.

  Then, this invention makes it a subject to provide the die raising / lowering apparatus for press machines which can be operate | moved with high synchronism with the several raising / lowering member incorporated in a press machine, and raising / lowering in the state which supported the metal mold | die. .

  In order to solve the above-described problems, a die lifting device for a press machine according to the present invention includes a plurality of lifting members that lift and lower while supporting the die during replacement of the press machine die, and driving of the lifting member. An electric motor as a power source and a motion conversion mechanism that converts the rotational motion of the motor into the lifting motion of the lifting member are provided.

  That is, by adopting a configuration in which a plurality of elevating members are driven by an electric motor via a motion conversion mechanism, synchronization adjustment of each elevating member can be easily performed, and high synchronism can be obtained.

  Here, as the motion conversion mechanism, a worm that receives rotation from the electric motor, a worm wheel that meshes with the worm, a screw shaft that rotates integrally with the worm wheel, and a screw shaft that is screw-coupled to the screw shaft, What consists of a nut member which raises / lowers with rotation of a screw axis | shaft in the state by which rotation was regulated integrally with the raising / lowering member is employable.

  As described above, the die lifting device for a press machine according to the present invention facilitates synchronous adjustment of each lifting member by using an electric motor as a driving power source of a plurality of lifting members that lift and lower while supporting the die. Since it can be performed and high synchronism is obtained, the mold can be moved up and down stably, and there is little possibility of damaging the mold positioning key when replacing the mold. Therefore, in the press machine incorporating this mold lifting device, the mold positioning accuracy and thus the product quality can be maintained well over a long period of time.

  In addition, compared to the case of using a mold lifting device driven by fluid pressure such as a conventional hydraulic cylinder, the time required for maintenance such as initial adjustment and adjustment at the time of lifting operation failure is greatly reduced, There is also an advantage that troubles due to fluid leakage, for example, the occurrence of a fire when oil leaks in the vicinity of a high-temperature workpiece is eliminated.

The top view which shows the assembly state to the press machine of the die raising / lowering apparatus of embodiment 1 is an enlarged plan view of the main part of FIG. Sectional view along line III-III in FIG. a and b are front cross-sectional views of main parts for explaining a die replacement procedure in the press machine of FIG. Front sectional view of the main part showing the step of taking out the mold from the press machine of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a state in which a die lifting device for a press machine (hereinafter simply referred to as “die lifting device”) 1 according to an embodiment is incorporated in a press machine. In the press machine, a lower frame to which a bolster 3 is fixed and an upper frame (both not shown) are connected by four tie rods 2, and a slide (not shown) arranged above the bolster 3 is moved up and down. The workpiece is machined by an upper die (not shown) attached to the lower surface side of the slide and a lower die 4 attached to the upper surface side of the bolster 3 by reciprocating at a constant stroke.

  The lower mold 4 has wheels 5 attached to the positions of four vertices of a rectangle inside each side of the lower surface, and can be easily moved horizontally when the mold is changed later (FIG. 5). reference). On the other hand, on the upper surface of the bolster 3, there are four circular holes 6 into which the wheels 5 of the lower mold 4 are immersed during work processing, and two circular holes 6 aligned in the mold moving direction (left-right direction in FIG. 1). A pair of wheel grooves 7 are provided that extend along a straight line passing through the center and guide each wheel 5 of the lower mold 4 when the mold is exchanged. Further, a rectangular parallelepiped mold positioning key 8 is provided at the center of the upper surface of the bolster 3, and the mold positioning key 8 is fitted into a recess 9 (see FIG. 5) provided at the center of the lower surface of the lower mold 4. At the same time, a part of each wheel 5 of the lower mold 4 is immersed in the circular hole 6 on the upper surface of the bolster 3, and the lower surface of the lower mold 4 comes into contact with the upper surface of the bolster 3. Is set to the state when machining the workpiece.

  As shown in FIGS. 1 to 3, the mold lifting apparatus 1 of the embodiment includes four lifting members 10 that lift and lower while supporting the molds (the upper mold and the lower mold 4) during mold replacement. The four servo motors (electric motors) 11 serving as driving power sources for the lifting members 10 and the four motion converting mechanisms 12 for converting the rotational motion of the servo motors 11 to the lifting motions of the lifting members 10, respectively. Yes.

  Each of the elevating members 10 has a cylindrical shape that fits into the circular hole 6 on the upper surface of the bolster 3, and a radial groove 13 that is continuous with the wheel groove 7 on the upper surface of the bolster 3 when formed on the upper end surface. . Further, a plurality of protrusions 14 are provided on the outer peripheral surface of the lower end, and the rotation is restricted by fitting each of these protrusions 14 into the axial groove 15 formed on the inner peripheral surface of the circular hole 6. It is designed to move up and down in the state. A plurality of ring-shaped guide bushes (sliding members) 16 are embedded in the inner peripheral surface of the circular hole 6 so that the elevating movement of the elevating member 10 can be performed smoothly.

  Each of the motion conversion mechanisms 12 is screwed to the worm 17 that receives rotation from the servo motor 11, the worm wheel 18 that meshes with the worm 17, the screw shaft 19 that rotates together with the worm wheel 18, and the screw shaft 19. The nut member 20 is moved up and down with the rotation of the screw shaft 19 in a state in which the rotation is restricted integrally with the lifting member 10.

  Then, by lowering each lifting member 10 of the mold lifting device 1 to the lower limit position, a part of the wheel 5 of the lower mold 4 placed at the position of the radial groove 13 at the upper end of each lifting member 10 is bolstered. 3, the mold positioning key 8 of the bolster 3 is fitted into the recess 9 at the center of the lower surface of the lower mold 4, and the lower surface of the lower mold 4 is in contact with the upper surface of the bolster 3, The lower mold 4 can be set to the state when machining the workpiece.

  Next, the procedure of die replacement in this press machine will be described. When the press work before the mold replacement is completed, the slide is first lowered to the bottom dead center, and the upper mold 21 is removed from the slide and placed on the lower mold 4 as shown in FIG. At this time, the lower mold 4 is in the state at the time of machining the workpiece described above, and each lifting member 10 of the mold lifting apparatus 1 is in the lower limit position. Then, the slide from which the upper mold 21 has been removed is raised to a position that does not interfere with the subsequent mold replacement work.

  After raising the slide as described above, the mold lifting device 1 is driven from the state of FIG. 4A to raise each lifting member 10 to the upper limit position as shown in FIG. 4B. Then, the wheel 5 is supported by each lifting member 10, the lower mold 4 on which the upper mold 21 is placed is lifted above the mold positioning key 8, and the radial groove 13 at the upper end of each lifting member 10 is It becomes continuous at the same height as the wheel groove 7 on the upper surface of the bolster 3.

  Then, from the state of FIG. 4B, as shown in FIG. 5, the table 22 of the carriage (the whole is not shown) that has been waiting in advance at the die replacement position in the vicinity of the press machine is moved and its upper surface is moved. A pair of wheel grooves 23 provided on the bolster 3 are respectively connected to the wheel grooves 7 of the bolster 3, and the molds (upper mold 21 and lower mold 4) are moved horizontally along the wheel grooves 7 and 23 of the bolster 3 and the table 22. Then, the bolster 3 is transferred to the table 22. The carriage with the mold placed on the table 22 is moved to a mold carry-in / out position away from the press machine.

  Thereafter, a new mold is set on the press machine in the reverse order of the above. That is, the carriage on which the new mold is placed is moved to the mold exchange position in the vicinity of the press machine, the mold is transferred from the carriage table 22 to the bolster 3, and each wheel 5 of the lower mold 4 is moved up and down by the lifting member 10. Until the position of the radial groove 13 is reached. In this state, the mold lifting device 1 is driven to lower each lifting member 10 to the lower limit position so that a part of each wheel 5 of the lower mold 4 is immersed in the circular hole 6 of the bolster 3 and the lower The recess 9 on the lower surface of the mold 4 is fitted into the mold positioning key 8. Then, the slide is lowered to the bottom dead center, the upper mold 21 is attached to the slide, and the carriage is returned to the mold loading / unloading position.

  The mold lifting device 1 has the above-described configuration, and uses the servo motor 11 as a driving power source for the plurality of lifting members 10 that lift and lower while supporting the mold. It can be performed easily and high synchrony can be obtained. Therefore, when changing the mold, the mold can be moved up and down stably, there is less risk of damaging the mold positioning key 8, and compared with the conventional one using a hydraulic cylinder driven by fluid pressure. The time required for initial adjustment and maintenance can be shortened, and troubles due to fluid leakage can be eliminated.

  In the above-described embodiment, the lower mold 4 is provided with the wheels 5 so that the mold can be easily replaced between the bolster 3 and the carriage table 22. Instead of the lifting member of the embodiment, a die between the bolster and the carriage is used by using a lifting roller that is positioned below the upper surface of the bolster at the time of workpiece processing and lifts the lower die upward from the die positioning key at the time of die replacement. At the time of replacement, the mold may be moved horizontally on the lifting roller. Further, each motion conversion mechanism of the mold lifting device of the present invention is not limited to that of the embodiment, and any mechanism may be used as long as it has a function of converting the rotational motion of the electric motor into the lifting motion of the lifting member.

DESCRIPTION OF SYMBOLS 1 Mold raising / lowering device 3 Bolster 4 Lower die 5 Wheel 6 Circular hole 7 Wheel groove 8 Mold positioning key 9 Recess 10 Lifting member 11 Servo motor (electric motor)
12 motion conversion mechanism 17 worm 18 worm wheel 19 screw shaft 20 nut member 21 upper mold 22 table 23 wheel groove

Claims (2)

  A plurality of elevating members that move up and down while supporting the die when exchanging the die for a press machine, an electric motor as a driving power source for the elevating member, and a rotational movement of the electric motor is converted into an elevating movement of the elevating member A die lifting device for a press machine, comprising a motion conversion mechanism that performs the same.   The motion conversion mechanism includes a worm that receives rotation from the electric motor, a worm wheel that meshes with the worm, a screw shaft that rotates together with the worm wheel, and a screw shaft that is coupled to the screw shaft, and is integrated with the lifting member. 2. The die lifting device for a press machine according to claim 1, comprising a nut member that moves up and down with rotation of the screw shaft in a state in which the rotation is restricted.

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