JP2006321204A - Mold clamping device of injection molding machine and its assembling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure capable of efficiently performing the assembling work of a mold clamping device. <P>SOLUTION: A through-hole 36 of a tie bar 22 is formed to a mold clamping piston 30 and the ring nut 38 threaded with and connected to the outer periphery of the end part of the tie bar 22 is provided while a diametrically expanded fitting and mounting part 42 for locking the ring nut 38 by stepped surfaces (50 and 52) is formed to one end part of the through-hole 36 provided to the piston 30 and the mold clamping force by virtue of the hydraulic pressure received by the piston 30 within a mold clamping cylinder 32 is transmitted to the tie bar 22 through the ring nut 38. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mold clamping device of an injection molding machine for molding a plastic or aluminum product and an assembling method thereof.

In the conventional injection molding machine, as shown in FIG. 4, a pair of fixed mold 2 and movable mold 1 are attached to a fixed platen 3 and a movable platen 4, and four tie bars 5 are moved relative to the fixed platen 3. The movable platen 4 is moved toward and away as a guide to perform mold matching and generate a mold clamping force via a tie bar 5. In recent injection molding machines, a high-speed and long-stroke mold opening / closing cylinder mechanism 6 is used for mold matching, and a low-speed and short-stroke mold clamping cylinder mechanism 7 is used for mold clamping. . In this type of mold clamping device, one end of four tie bars 5 connecting the fixed platen 3 and the movable platen 4 is fixed to the fixed platen 3 or the movable platen 4, and the ring groove provided on the other end side is half-cut. A method is adopted in which a large clamping force is obtained by operating the clamping cylinder mechanism 7 in a state where it is bitten by the nut 8 and fixed and held, and then supported by the reaction force by the tie bar 5. Then, molten aluminum or plastic is injected and injected into the mold from the injection side, and after cooling and solidification, the mold is opened and the molded product is taken out.
Such a mold clamping device is generally widely used because the machine length is shorter and the space can be saved as compared with a conventional toggle type mold clamping device.
Japanese Patent Laid-Open No. 5-2699749 JP-A-4-348916

  Incidentally, the mold clamping cylinder mechanism 7 in such an injection molding machine is a cylinder formed on the fixed platen 3 by attaching a mold clamping piston 9 to one end portion of the tie bar 5 by screw connection, as shown in detail in FIG. 10 is used. Since the large-diameter, heavy-weight mold clamping piston 9 is connected to the tie bar 5 with screws, when assembling an injection molding machine, it is extremely difficult to reassemble the tie bar 5 and the mold clamping piston 9 in the field work. Yes, after assembling the clamping piston 9 to the tie bar 5 at the factory, it was shipped together without being disassembled.

  Therefore, conventionally, since the tie bar 5 and the mold clamping piston 9 are integrated, as shown in FIG. 6, in the field installation work, it is necessary to insert a long tie bar 5 from the injection side when incorporating the fixed platen 3, In order to avoid interference, the construction on the exit side could only be started after the tie bar 5 was installed. For this reason, there has been a problem that the assembly period of the injection molding machine becomes long.

  In addition, it is necessary to re-install the packing around the mold clamping piston 9 at the site construction. Since there are 2 sets of packing and shims for each tie bar, a total of 8 sets, shim adjustment etc. takes much time and Variations in packing mounting height due to variability, oil leakage is likely to occur, and the time until the pressure rise limit in the clamping cylinder varies, affecting the quality of the molded product. In addition, the work of recovering leaked oil, replenishment of oil, etc. is increased, and the maintenance, productivity, and environmental performance are lowered, so there is a high demand for improvement.

  An object of the present invention is to provide a mold clamping device of an injection molding machine having a structure capable of efficiently assembling a mold clamping device, paying attention to the above-mentioned conventional problems. Also, the purpose is to provide a mold clamping device that can perform assembly work such as pressurizing seals at the factory and does not require basic seal adjustment work between piston cylinders during on-site assembly work. To do. Another object of the present invention is to provide an assembling method that has very little influence on the construction work on the injection side when assembling the mold clamping device.

  In order to achieve the above object, a mold clamping device of an injection molding machine according to the present invention includes a fixed platen and a movable platen connected by a plurality of tie bars, and a tie bar tip portion in a mold clamping cylinder provided on the fixed platen. In the mold clamping device of the injection molding machine to which the piston is mounted, a through-hole of the tie bar is formed in the piston, and a ring nut that is screwed to the outer periphery of the end portion of the tie bar is provided. On the one end side of the through-hole, a fitting insertion portion having an enlarged diameter for engaging the ring nut with a stepped surface is formed, and the clamping force by the hydraulic pressure received by the piston in the clamping cylinder is applied to the ring nut. It can be transmitted to the tie bar.

  In this case, the mold clamping cylinder in which the tie bar through hole is formed may be structured so that it can be transported in a state in which cylinder components are incorporated at the time of factory assembly. That is, cylinder components such as packing, piston, packing presser and the like are assembled in the cylinder without being removed.

  The mold clamping device assembling method of the injection molding machine according to the present invention is such that a fixed platen and a movable platen are linked by a plurality of tie bars, and a piston at the tip of the tie bar is mounted in a mold clamping cylinder provided on the fixed platen. In a method of assembling a mold clamping device of an injection molding machine, a piston having a hole through which a tie bar can pass is mounted in advance in a mold clamping cylinder of a fixed platen, and the movable platen is movable with respect to a fixed platen and a movable platen arranged opposite to each other The tie bar passes from the platen side to the fixed platen, or the injection side passes the tie bar through the fixed platen, and a ring nut is screwed and fixed to the through end of the tie bar. It is characterized in that a nut is inserted and assembled.

  According to the above configuration, the tie bar with the ring nut removed can be inserted into the mold clamping cylinder of the fixed platen from the rear side of the movable platen in the field installation work, so simultaneous installation work on the mold clamping side and the injection side is possible. The construction period can be shortened because the construction can proceed without any restrictions on the process. Moreover, since the piston and packing can be shipped together with the fixed platen without disassembling, the quality at the time of shipping inspection can be maintained on site. Therefore, the cost and the number of days for reassembling the packing at the site and adjusting the shim can be reduced.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a mold clamping device for an injection molding machine and an assembling method thereof according to the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a partial cross-sectional side view schematically showing the overall configuration of a mold clamping device according to an embodiment. As shown in the figure, the mold clamping device 100 includes a fixed platen 14 fixedly disposed on the base 12 and a movable platen 16 disposed so as to face the fixed platen 14 and move toward and away from the fixed platen 14. Equipped. A stationary mold 18 and a movable mold 20 are respectively attached to the facing portions of the platens 14 and 16. A mold opening / closing cylinder mechanism 23 is provided between the fixed platen 14 and the movable platen 16 for matching the movable mold 20 and the fixed mold 18, which has a smaller diameter than the mold clamping cylinder mechanism 28 described later. The cross section has a long stroke structure, enabling high-speed movement.

  Four tie bars 22 are placed between the fixed platen 14 and the movable platen 16 so as to be positioned at the four corners of the region surrounding the molds 18 and 20. The tie bar 22 extends toward the movable platen 16 with the end of the mold clamping cylinder mechanism 28 as a fixed end, and penetrates the movable platen 16. A plurality of ring grooves 24 are formed at a constant pitch on the side of the tie bar 22 that penetrates the movable platen 16. Corresponding to this ring groove portion, a half nut mechanism 26 is provided on the outer surface portion of the movable platen 16, and the half nut is engaged with the ring groove 24 at the position where the dies 18 and 20 are mated. Both are combined to support the reaction force during mold clamping.

  On the other hand, a mold clamping cylinder mechanism 28 is configured at the end of the tie bar 22 located on the fixed platen 14 side. The mold clamping cylinder mechanism 28 includes a ring nut 38 fixed to the end of the tie bar 22 and a mold clamping formed on the back surface of the fixed platen 14 (on the side opposite to the mold mounting surface) through which the mold clamping piston 30 is inserted. After the molds are aligned, hydraulic oil is supplied to a hydraulic chamber 34 formed between the cylinders 32 to pull the movable platen 16 to the fixed platen 14 side via the tie bars 22, thereby clamping the mold. Is generated.

  In this embodiment, in this embodiment, as shown in detail in FIG. 2, a through-hole 36 of the tie bar 22 is formed in the mold clamping piston 30 and is screwed to the outer periphery of the end portion of the tie bar 22. A ring nut 38 is provided. On the other hand, on one end portion side of the through hole 36 provided in the mold clamping piston 30, an expanded fitting mounting portion 42 for engaging the ring nut 38 with the engaging step portion 50 is formed. As a result, the mold clamping force by the hydraulic pressure received by the piston 30 in the mold clamping cylinder 32 is transmitted to the tie bar 22 via the ring nut 38.

  More specifically, the mold clamping piston 30 is formed around the through hole 36 of the tie bar 22 and has a cylindrical piston main body 30 a and is fitted into the mold clamping cylinder 32 formed on the fixed platen 14. A hydraulic chamber 34 is formed between the joint portions of the two step surfaces 40 so that the piston main body 30a can be pushed rightward in the drawing by the introduced hydraulic pressure. A sleeve 30b is extended on one end side (die side) of the piston main body 30a. The sleeve 30b is inserted between the tie bar 22 and the hole of the fixed platen 14, and a packing 44 is provided on the joint surface leading to the hydraulic chamber 34. Is pressed and held by the packing presser 46. The packing presser 46 has a flange formed at the end of the cylindrical ring, and the packing 44 is pressed against the end surface of the cylindrical ring, and the shim 48 is interposed in the flange to adjust the presser dimension. I let you.

On the other hand, the engagement step portion 50 is formed in the opening of the through hole 36 on the outer end side of the piston body 30a to double the diameter, and the maximum diameter expanding portion on the opening end side is the ring nut 38 described above. The fitting mounting portion 42 is used. The ring nut 38 has a female screw portion 38 a that is screwed into a male screw portion 22 a formed at the end portion of the tie bar 22, and is screwed to the end portion of the tie bar 22. A taper sleeve 38b that relieves the screw stress of the male screw portion 22a and the female screw portion 38a is provided at the distal end portion of the ring nut 38. The outer peripheral portion of the proximal end portion of the taper sleeve 38b is provided with a mold from the piston 30. A pressure receiving step 52 for receiving a tightening force is provided so as to contact the piston side engaging step 50. As a result, the mold clamping force generated by the mold clamping piston 30 due to the hydraulic pressure is transmitted to the tie bar 22 through the ring nut 38.
The mold clamping piston 30, the ring nut 38, and the tie bar 22 are assembled, and an end plate 54 shared by these component end faces is fixed with a bolt, a knock pin, or the like, and these are configured to behave integrally.

  In order to prevent hydraulic leakage from the sliding surface between the mold clamping piston 30 and the mold clamping cylinder 32 communicating with the hydraulic chamber 34 at the injection side end surface portion of the fixed platen 14, the packing 44A is pressed and held by the packing presser 46A. I try to let them. This is also configured in the same manner as the piston sleeve 30b side, and the packing 44A is pressed by a packing presser 46A in which a flange is formed at the end of the cylindrical ring, and a shim 48A is interposed in the flange portion. The presser dimensions are adjusted.

  In the mold clamping device 100 having such a configuration, the force generated in the mold clamping piston 30 by hydraulic pressure is: piston 30 → ring nut 38 → tie bar 22 → half nut mechanism 26 → movable platen 16 → molds 18, 20 → fixed. The mold clamping force can be applied to the molds 18 and 20 by being transmitted to the platen 14.

  An injection molding machine equipped with such a mold clamping device 100 is assembled once after manufacture of each part, and after performing trial operation and inspection in a factory, it is disassembled and shipped. At the time of disassembly, the ring nut 38 is removed from the tie bar 22, and the tie bar 22 is removed from the mold clamping piston 30. The mold clamping piston 30 is shipped together with the packings 44 and 44A and the packing retainers 46 and 46A while being incorporated in the fixed platen 14. The ring nut 38 may be removed from the tie bar 22 and the tie bar 22 may be removed from the mold clamping piston 30 to form a hollow structure.

  In the field installation work, after the fixed platen 14 and the movable platen 16 are placed on the machine base 12, the tie bar 22 is inserted from the rear side of the movable platen 16 and passed through the mold clamping piston 30 in the fixed platen 14. Then, a ring nut 38 is attached to the end portion of the tie bar 22 with a screw and fixed.

Since it is not necessary to insert the long tie bar 22 from the injection side and there is no interference, installation work on the injection side and the mold clamping side can be performed simultaneously. If there is no space for inserting the tie bar on the mold clamping device side and insertion from the movable platen side is not possible, or when simultaneous work is not necessary, it is of course possible to insert from the injection side.
The mold opening / closing cylinder mechanism 28 can be a combination structure of a servo motor and a ball screw.

  As described above, in the present embodiment, the mold clamping piston 30 is provided with the through hole 36 of the tie bar 22, the ring nut 38 that is screwed to the outer periphery of the end portion of the tie bar 22 is provided, and the piston 30 is provided. On one end portion side of the through hole 36 formed, a fitting mounting portion 42 having an enlarged diameter for engaging the ring nut 38 with a stepped surface (50, 52) is formed, and the piston 30 in the mold clamping cylinder 32 receives it. The structure is such that hydraulic clamping force is transmitted to the tie bar 22 via the ring nut 38. When assembling the mold clamping device 100, the mold clamping piston 30 provided with a hole 36 through which the tie bar 22 can pass is mounted in the mold clamping cylinder 32 of the fixed platen 14 in advance, and is movable with the fixed platen 14 arranged oppositely. A tie bar 22 is passed through the fixed platen 14 from the movable platen 16 side with respect to the platen 16, and a ring nut 38 is screwed and fixed to the through end of the platen 16. Since the ring nut 38 is fitted and assembled to 42, the assembly work on the injection device side can be performed in parallel at the time of on-site assembly, and the work efficiency can be greatly improved.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a mold clamping device of an injection molding machine that molds plastic or aluminum products and an assembly method thereof.

It is a partial section side view of an injection molding machine provided with a mold clamping device concerning an embodiment. It is a detailed sectional view of the mold clamping cylinder mechanism of the same device. It is a disassembled explanatory drawing which shows the assembly state of the same apparatus. It is a partial cross section side view of the conventional injection molding machine. It is a detailed sectional view of the mold clamping cylinder mechanism of the same device. It is a disassembled explanatory drawing which shows the assembly state of the same apparatus.

Explanation of symbols

100 ......... Clamping device, 12 ......... Base, 14 ......... Fixed platen, 16 ......... Movable platen, 18 ......... Fixed mold, 20 ......... Moveable mold, 22 ......... Tie bar, 23 ......... Cylinder opening / closing cylinder mechanism, 24 ......... Ring groove, 26 ......... Half nut mechanism, 28 ......... Clamping cylinder mechanism, 30 ......... Clamping piston, 30a ......... Piston body, 30b ... …… Sleeve, 32 …… Clamping cylinder, 34 ……… Hydraulic chamber, 36 ………… Through hole, 38 ……… Ring nut, 38a ……… Female thread, 38b ……… Taper sleeve, 40 …… ... Step surface, 42 ......... Fitting mounting part, 44, 44A ......... Packing, 46, 46A ......... Packing presser, 48, 48A ......... Shim, 50 ......... Engagement step part (piston side) 52 ……… Pressure step, 54 ……… End plate.

Claims (3)

In a mold clamping device of an injection molding machine in which a fixed platen and a movable platen are connected by a plurality of tie bars, and a piston at the tip of a tie bar is mounted in a mold clamping cylinder provided on the fixed platen.
A through hole of the tie bar is formed in the piston, and a ring nut screwed to the outer periphery of the end of the tie bar is provided, and the ring nut is provided at a step surface on one end side of the through hole provided in the piston. An injection molding characterized in that a fitting mounting portion having an enlarged diameter to be engaged is formed, and the mold clamping force by the hydraulic pressure received by the piston in the mold clamping cylinder can be transmitted to the tie bar via the ring nut. Machine clamping device.   2. The mold clamping apparatus for an injection molding machine according to claim 1, wherein the mold clamping cylinder in which the tie bar through hole is formed is configured to be transported in a state in which cylinder components are incorporated at the time of factory assembly. In the mold clamping device assembling method of the injection molding machine in which the fixed platen and the movable platen are connected by a plurality of tie bars, and the piston at the tip of the tie bar is mounted in the mold clamping cylinder provided in the fixed platen.
A fixed platen clamping cylinder is pre-installed with a piston with a hole through which the tie bar can penetrate, and the fixed platen and movable platen arranged opposite to each other penetrate the tie bar from the movable platen side or from the injection side. Injection molding, characterized in that a tie bar is passed through a fixed platen, a ring nut is screwed and fixed to an end of the fixed platen, and the ring nut is fitted into a mounting portion of a tie bar through-hole of the piston which is expanded. Assembling method of mold clamping device.

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