JP3506834B2 - Injection molding machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-line screw type injection molding machine, and more particularly to a structure of an injection unit of the injection molding machine. 2. Description of the Related Art In a hydraulically driven in-line screw type injection molding machine, an injection unit (injection system mechanism unit) includes a hydraulic motor for rotating a screw, and a hydraulic motor for driving a screw back and forth. And a hydraulic nozzle touch cylinder (hereinafter, a nozzle touch cylinder) for driving the entire injection unit forward and backward.
Further, in a model requiring high-speed injection, a hydraulic accumulator (hereinafter, referred to as an accumulator) for high-speed injection (to supply hydraulic oil accumulated in a forward oil chamber of an injection cylinder) is provided near an injection unit. It was to be arranged in. In the injection unit of a conventional injection molding machine, the above-mentioned hydraulic drive sources (hydraulic motor, injection cylinder, nozzle touch cylinder) and accumulators are individually arranged, and hydraulic lines for these are also individually drawn. Had been turned. [0004] As described above, in the injection unit of the conventional injection molding machine, each hydraulic drive source and accumulator are individually arranged and mounted, and hydraulic piping for these is also individually pulled. It is difficult to keep the injection unit compact because it has been turned around, and since many hydraulic pipes are routed, there are problems in terms of safety, oil contamination, and aesthetics. There was a problem that loss easily occurred. In particular, in the feedback control, there is also a problem that the length of the pipeline between the accumulator and a driving source (injection cylinder) to which the pressure oil from the accumulator is supplied becomes long, and the responsiveness is deteriorated. [0005] The present invention has been made in view of the above points,
The purpose is to make the injection unit compact and to provide hydraulic piping for each hydraulic drive source and accumulator, especially in a hydraulically driven inline screw type injection molding machine equipped with an accumulator for high-speed injection. Are obtained in a common manner, thereby providing excellent safety and aesthetic appearance, reducing oil stains, and further reducing piping resistance. In order to achieve the above object, the present invention provides a hydraulically driven in-line screw type injection molding machine, comprising: a hydraulic motor, an injection cylinder,
An accumulator, a nozzle touch cylinder, and a valve group for controlling these components are integrated into one manifold block. Further, the injection cylinder has a hollow structure, and a rotation transmission mechanism having a spline shaft coupling mechanism for transmitting rotation of the hydraulic motor to the screw is housed inside the injection cylinder. An embodiment of the present invention will be described below. FIG. 1 is a partially cutaway front view showing a configuration of an injection system of an in-line screw type injection molding machine according to one embodiment of the present invention (hereinafter, referred to as the present embodiment), and FIG. FIG. 3 is a right side view of the injection unit of the injection molding machine of the present embodiment, and FIG. 4 is an enlarged view of a main part of FIG. In FIG. 1, reference numeral 1 denotes a main body base of an injection molding machine, and an injection unit generally indicated by reference numeral 4 is mounted on support bases 2 and 3 fixed on the main body base 1. Reference numeral 5 denotes a fixed die plate of a mold opening / closing mechanism system mounted on the main body base 1. Reference numeral 6 denotes a unit base member of the injection unit 4. The unit base member 6 is mounted on the supports 2 and 3 so as to be slidable by a predetermined amount. Each member constituting the injection unit 4 is mounted on the unit base member 6, and a nozzle touch cylinder 15 described later is provided.
By the operation described above, the entire injection unit 4 including the unit base member 6 moves forward and backward on the support bases 2 and 3. A heating cylinder holding block 7 is mounted and fixed on the front side (left side in FIG. 1) of the unit base member 6, and the rear end of the heating cylinder 8 is fixed to the heating cylinder holding block 7. . A nozzle 9 is fixed to the distal end side of the heating cylinder 8, and a band heater (not shown) is wound around the outer periphery of the heating cylinder 8 and the nozzle 9. During the molding operation, the nozzle 9 is pressed by a nozzle touch cylinder 15 described later against a resin injection port into a mold (not shown). Reference numeral 10 denotes a screw, which is disposed in the heating cylinder 8 so as to be rotatable and forward and backward, and a rotation drive mechanism and a forward and backward drive mechanism to be described later are connected to the rear end side. Reference numerals 7a and 8a denote resin material input ports formed in the heating cylinder holding block 7 and the heating cylinder 8, respectively.
The resin material dropped and thrown from a hopper (not shown) attached to the heating cylinder holding block 7
The screw 10 is supplied to the rear end side of the screw 10 through a and 8a. Reference numeral 11 denotes a manifold block which is a feature of the present invention, and is mounted and fixed to the rear side (the right side in FIG. 1) of the unit base member 6. As shown in FIGS. 1 to 3, this manifold block 11 has a screw 1
0, a hydraulic motor 12 for rotating and driving the screw 10, an injection cylinder 13 for driving the screw 10 forward and backward, and an accumulator 14 for supplying hydraulic oil accumulated in a forward oil chamber 13a of the injection cylinder 13. A nozzle touch cylinder 15 for driving the entire injection unit 4 back and forth, and a valve group for controlling them (a servo valve 16 for controlling the injection cylinder 13, a valve 17 for controlling the hydraulic motor 12, a nozzle touch cylinder 15 The control valve 18) is integrated. That is,
All the hydraulic circuit components necessary for the injection unit 4 are incorporated in the manifold block 11. A P (pipe) line pipe 19 is provided between the manifold block 11 and the main body base 1.
The injection unit 4 is connected by a T (tank) line pipe 20 and a drain line pipe (pipe for return oil at a lower pressure than the T line) 21, and through these three pipes 19, 20, 21. All the hydraulic circuit components are connected to a pump and a tank (not shown) of the main body base 1 by piping in the manifold block 11. In this embodiment, the nozzle touch cylinder 1
5 includes a pair of manifold blocks 11 (a lower front portion and an upper rear portion of the manifold block 11). As shown in FIG. 2, the piston body of the nozzle touch cylinder 15 includes a bar body 22. The rear end portion is always in contact. Each bar body 22 has an intermediate portion fixed to the heating cylinder holding block 7,
The tip of the bar body 22 is always in contact with the fixed die plate 5. Therefore, if the operating oil is poured into the forward oil chamber of the nozzle touch cylinder 15, the injection unit 4 moves forward, the nozzle 9 is pressed against the resin injection port into the mold (not shown), and the nozzle touch cylinder 15 retreats. When the working oil is poured into the oil chamber, the injection unit 4 is retracted, and the nozzle 9 is separated from the resin injection port to the mold (not shown). Note that the two nozzle touch cylinders 15
It is controlled in common by one valve 18. Next, a rotary drive mechanism and a forward / backward drive mechanism of the screw 10 will be described with reference to FIG. As shown in FIG. 4, the injection cylinder 13 described above is disposed in the manifold block 11, and in this embodiment, the injection cylinder 13 has a hollow cylindrical shape. Reference numerals 13a, 13b, and 13c denote a forward oil chamber, a backward oil chamber, and a piston body of the injection cylinder 13, respectively. When hydraulic oil is poured into the forward oil chamber 13a via the accumulator 14 and the servo valve 16, the piston When the body 13c moves forward and the operating oil flows into the retraction oil chamber 13b, the piston body 13c retreats (actually, supply of oil to the retraction oil chamber 13b during the molding operation). Is the screw 1 during the weighing process
0 for back pressure control). 23 is connected to the rear end of the screw 10
The tip of the piston body 13c of the injection cylinder 13 is coupled to the rotating shaft body 23 via a plurality of bearings, and the piston body 13c and the rotating shaft body 23 are in the axial direction. , And the rotary shaft 23 is held rotatably with respect to the piston 13c. Therefore, the rotation shaft 23 and the screw 10 are integrally driven forward and backward by the forward and backward movement of the piston body 13c of the injection cylinder 13. Reference numeral 24 denotes a rotary drive, which is rotatably disposed inside the injection cylinder 13 via a bearing.
The output shaft 12 of the hydraulic motor 12 is
a is connected and fixed. Reference numeral 24a denotes a shaft rotation drive unit of the rotation drive unit 24, and the rotation shaft unit 23a
Are connected to each other by a spline shaft. Therefore, the rotation of the output shaft 12a of the hydraulic motor 12 is transmitted to the screw 10 via the rotary drive 24 and the rotary shaft 23. That is, at the time of the metering process, the screw 10 in the heating cylinder 8 is rotated by the rotation of the hydraulic motor 12 to transfer the resin material supplied to the rear side of the screw 10 to the tip side of the screw 10 while kneading and plasticizing. Thus, the molten resin is stored at the tip end of the screw 10. At this time, the screw 10 that retreats due to the resin pressure of the molten resin stored on the tip side of the screw 10 slides backward with respect to the rotary driving body 24 while controlling the back pressure. As described above, the injection unit 4 of the injection molding machine according to the present embodiment includes the hydraulic motor 12 and the injection cylinder 1
3, an accumulator 14, a nozzle touch cylinder 15, and a valve group (16, 1) for controlling these.
7, 18) are integrated into one manifold block 11, so that the entire injection unit 4 can be made compact. Each hydraulic drive source of the injection unit 4 (12, 13, 15)
Hydraulic piping for the accumulator 14 and the accumulator 14 can be combined into a common one, which is superior in terms of safety and aesthetics as compared with a case where a large number of piping are routed, and oil contamination due to leakage from the piping. There are fewer places. Further, since the common manifold block 11 is used for all the hydraulic circuit components of the injection unit 4, the entire pipeline length can be shortened as compared with the conventional case, and the pipeline resistance is reduced. The responsiveness is improved, and the feedback performance of the servo valve 16 is also improved. Further, since the injection cylinder 13 has a hollow structure, a rotation transmission mechanism having a spline shaft coupling mechanism for transmitting the rotation of the hydraulic motor 12 to the screw 10 is housed inside the injection cylinder 13. The injection cylinder 13 and the rotation transmitting mechanism can be arranged in a space-efficient manner without increasing the overall length of the injection unit 4, and the injection unit 4 as a whole can also be compactly arranged in this respect. Furthermore, the hydraulic motor 12 is not moved forward and backward together with the screw 10,
Is fixed to the injection unit 4, so that the weight of the member that advances together with the screw 12 during the injection operation (operating weight at the time of the injection operation) can be reduced, thereby reducing the inertia. Therefore, the responsiveness is improved. For this reason, coupled with the effect of reducing the pipeline resistance,
The injection feedback performance is further improved. As described above, according to the present invention, the injection unit can be made compact in a hydraulically driven in-line screw type injection molding machine equipped with a high-speed injection accumulator. It becomes. Further, since the hydraulic piping for each hydraulic drive source and the accumulator can be integrated into a common one, excellent safety and aesthetic appearance can be obtained, oil contamination can be reduced, and piping resistance can be reduced. Furthermore, since the oscillation of the feedback control can be suppressed by reducing the pipe resistance, the gain can be increased, and the operating weight at the time of the injection operation can be reduced and the inertia can be reduced, so that the responsiveness is improved. Injection feedback performance is greatly improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cutaway front view showing a configuration of an injection system of an in-line screw type injection molding machine according to an embodiment of the present invention. FIG. 2 is a partially cutaway plan view of an injection unit of the in-line screw type injection molding machine according to one embodiment of the present invention. FIG. 3 is a right side view of an injection unit of the in-line screw type injection molding machine according to one embodiment of the present invention. FIG. 4 is an enlarged view of a main part of FIG. 1; [Description of Signs] 1 Main body base 2, 3 of injection molding machine Support base 4 Injection unit 5 Fixed die plate 6 Unit base member 7 Heating cylinder holding block 8 Heating cylinder 9 Nozzle 10 Screw 11 Manifold block 12 Hydraulic motor 12a Output shaft 13 Injection cylinder 13a Forward oil chamber 13b Retreat oil chamber 13c Piston body 14 Accumulator 15 Nozzle touch cylinder 16 Servo valve 17 for controlling injection cylinder 17 Valve for controlling hydraulic motor 18 Valve for controlling nozzle touch cylinder 19 P line piping 20 T Line pipe 21 Drain line pipe 22 Bar body 23 Rotary shaft 23a Spline shaft 24 Rotary driver 24a Shaft rotary driver

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 45/20 B29C 45/82

Claims (1)

(57) [Claims 1] By rotating a screw in a heating cylinder, a resin material supplied to a rear side of the screw is transferred to a tip side of the screw while being kneaded and plasticized. In an in-line screw type injection molding machine that stores molten resin at the tip side of the screw and injects and fills the molten resin into the mold by advancement of the screw, a hydraulic motor for driving the screw and a forward and backward drive for the screw A hydraulic injection cylinder, a hydraulic accumulator for supplying hydraulic oil accumulated in a forward oil chamber of the hydraulic injection cylinder, and a hydraulic nozzle touch cylinder for driving the entire injection unit back and forth. An injection molding machine characterized in that a group of valves for controlling are integrated into one manifold block. .