JP4820730B2 - Injection molding machine - Google Patents

Description

  The present invention relates to an injection molding machine including a drive mechanism that drives a movable part such as a screw forward and backward by a servo motor and a ball screw mechanism.

  In general, an injection molding machine in which a screw is driven forward and backward by a drive mechanism having a servo motor and a ball screw mechanism is known from Japanese Patent Application Laid-Open No. 10-151653, etc. The rear end of the screw is connected to the nut part of the ball screw mechanism, and a servo motor is provided on the side of the molding machine body, and the rotation of the servo motor is transmitted to the ball screw part of the ball screw mechanism via the rotation transmission mechanism. To do. As a result, the rotational motion transmitted from the servomotor is converted into a straight motion by the ball screw mechanism, and the screw moves forward and backward based on this straight motion. In this case, the rotation transmission mechanism is installed between the toothed drive pulley attached to the rotor shaft of the servo motor, the toothed driven pulley attached to the ball screw portion of the ball screw mechanism, and the toothed drive pulley and the toothed driven pulley. It is composed of a passed timing belt.

  However, such an injection molding machine requires a space for disposing a rotation transmission mechanism, which leads to an increase in the size of the molding machine main body, generation of noise, and further gain (control constant) due to a decrease in rigidity. There is a problem that the control becomes unstable because the value cannot be increased. In addition, since rotation is transmitted through the rotation transmission mechanism, control response, control accuracy, and control accuracy are deteriorated, and there is a problem that a bias load is applied to the rotor shaft of the servo motor from the timing belt. Arise.

Therefore, the present applicant has already proposed an injection molding machine for solving this problem in Japanese Patent Laid-Open No. 2001-88180. This injection molding machine includes a drive mechanism that drives a movable part such as a screw forward and backward by a servo motor and a ball screw mechanism, and also includes a ball screw part or an end part of a nut part and a servo motor that moves the movable part forward and backward. This is a direct connection of the end of the rotor shaft, which can contribute to downsizing and compacting of the molding machine body and noise reduction, as well as control responsiveness, control accuracy, control accuracy and rigidity. Stability can be improved, and in addition, a problem that an offset load is applied to the rotor shaft of the servo motor can be solved.
JP 10-151653 A JP 2001-88180 A

  However, the above-described conventional injection molding machine (Patent Document 2) has the following problems to be solved.

  First, since the end of the ball screw or nut and the end of the rotor shaft of the servo motor are directly connected, there is an advantage that it is possible to reduce the size and size and reduce noise associated with the need for a rotation transmission mechanism. However, on the other hand, the speed reduction function (pressure increasing function) of the rotation transmission mechanism cannot be used, and in order to secure the necessary high output, the servo motor is increased in size and cost.

  Second, since there is no rotation transmission mechanism responsible for the deceleration function (pressure increasing function), the servo motor itself is responsible for a wide range of control from low speed to high speed or from low pressure to high pressure. Therefore, there is a limit to control with high accuracy and stability, and it is not easy to perform accurate and flexible molding corresponding to various molded products.

  An object of the present invention is to provide an injection molding machine that solves the problems existing in the background art.

  In order to solve the above-described problem, the injection molding machine M according to the present invention includes a drive mechanism 1 that drives the movable portion 2 forward and backward by a servo motor 3o and a ball screw mechanism 4, and a ball screw that moves the movable portion 2 back and forth. When configuring an injection molding machine in which the end portion 5s of the ball screw portion 5 (or nut portion 6) of the mechanism 4 and the front end portion 7os of the rotor shaft 7o of the servo motor 3o are connected by the direct connection mechanism 8, a servo motor (basic In addition to the servo motor 3o, another servo motor (additional servo motor) 3a is mounted, and the additional servo motor 3a is attached to the rear end surface of the casing 60 of the basic servo motor 3o via the attachment 55a, and the basic servo motor 3o The rear end portion of the rotor shaft 7o or the front end portion 7as of the rotor shaft 7a of the additional servo motor 3a A restricting portion that is provided with an axial recess 15 on one of the end surfaces, inserts the other into the recess 15, and restricts relative rotation between the inner peripheral surface of the recess 15 and the outer peripheral surface facing the inner peripheral surface. 16 and provided with rotation transmission means 9 for connecting the rotor shaft 7o of the basic servo motor 3o and the rotor shaft 7a of the additional servo motor 3a by a direct coupling mechanism 13a, thereby providing additional servo to the rotor shaft 7o of the basic servo motor 3o. The present invention is characterized in that the rotation of the rotor shaft 7a of the motor 3a can be transmitted. In this case, according to a preferred aspect of the invention, the movable part 2 includes a movable member 2m that moves the movable mold Cm in the mold clamping mechanism 12 of the mold clamping device Mc or the screw 2s inserted into the heating cylinder 11 of the injection apparatus Mi forward or backward. Can be applied.

  An injection molding machine M according to another embodiment of the present invention includes a drive mechanism 1 that drives the movable portion 2 forward and backward by a servo motor 3o and a ball screw mechanism 4 in order to solve the above-described problem. An injection molding machine is configured in which the end portion 5s of the ball screw portion 5 (or the nut portion 6) of the ball screw mechanism 4 that moves the screw back and forth and the front end portion 7os of the rotor shaft 7o of the servo motor 3o are connected by the direct connection mechanism 8. At this time, in addition to the servo motor (basic servo motor) 3o, another additional servo motor 3a is mounted, and the end of the rotor shaft 7o projecting outside the basic servo motor 3o and the rotor shaft projecting outside the additional servo motor 3a. A basic servo module is provided by rotation transmission means 9 having a rotation transmission mechanism 14a using a gear transmission mechanism or a belt transmission mechanism interposed between end portions of 7a. Characterized in that the transmission configured to be able to rotate the rotor shaft 7a of the additional servo motors 3a to the rotor shaft 7o of data 3o.

  The injection molding machine M according to the present invention having such a configuration has the following remarkable effects.

  (1) In addition to the basic servo motor 3o, an additional servo motor 3a is mounted, and rotation transmission means 9 capable of transmitting the rotation of the rotor shaft 7a of the additional servo motor 3a to the rotor shaft 7o of the basic servo motor 3o is provided. Therefore, even when the end portion 5s of the ball screw portion 5 (or nut portion 6) of the ball screw mechanism 4 and the end portion 7os of the rotor shaft 7o of the basic servo motor 3o are connected by the direct connection mechanism 8, high output is easy. The basic servo motor 3o itself can be increased in size and cost can be avoided.

  (2) Since the plurality of servo motors 3o, 3a can be laid out flexibly, it is possible to contribute to the miniaturization of the entire injection molding machine M (drive mechanism 1) and to the plurality of servo motors 3o, 3a and the rotation transmission means 9. By adding selectivity, it is possible to easily perform accurate and flexible molding corresponding to various molded products, and to contribute to improvement of accuracy and stability in a wider range of control.

  (3) If the direct transmission mechanism 13a which connects the rotor shafts 7o and 7a to the rotation transmission means 9 is used, it can be avoided that the direct connection mechanism 13a protrudes outward from the outer diameter of the rotor shafts 7o and 7a. In addition, since the gain (control constant) can be increased by increasing the rigidity of the transmission system, the stability of the control can be increased, and the rotational output of low speed and high torque is directly transmitted, resulting in control responsiveness and control accuracy. In addition, the accuracy of control can be greatly improved.

  (4) If the rotation transmission mechanism 14a that transmits rotation by being interposed between the rotor shafts 7o and 7a is used for the rotation transmission means 9, in particular, the degree of freedom in designing the layout of the additional servo motor 3a can be increased. This can contribute to the miniaturization of the entire injection molding machine M (drive mechanism 1).

  (5) If the screw 2s inserted into the heating cylinder 11 of the injection device Mi is applied to the movable portion 2 according to a preferred aspect, in particular, it is possible to avoid an increase in size and cost of the injection device Mi and to control the injection process. Can contribute to the improvement of accuracy and stability.

  (6) If the movable member 2m for moving the movable mold Cm in the mold clamping mechanism 12 of the mold clamping device Mc is moved forward and backward according to a preferred mode, the size and cost of the mold clamping device Mc are increased. Can be avoided, and can contribute to improvement in accuracy and stability related to the control of the mold clamping process.

  Next, the best embodiment according to the present invention will be given and described in detail with reference to the drawings.

  First, a schematic configuration of an injection molding machine M according to the present embodiment will be described with reference to FIGS.

  FIG. 1 shows an injection device Mi of an injection molding machine M. In the figure, reference numeral 20 denotes a machine base. On the upper surface of the machine base 20, a separate injection stand 21 and injection drive base 22 are installed. Four guide shafts 23 are installed between the injection table 21 and the injection drive table 22, and a separate rear slider 25 is slidable on the guide shaft 23. Load (see FIG. 4).

  The front slider 24 is formed in a cylindrical shape having a hollow portion on the inner side, and a screw coupling 27 is rotatably supported by a bearing 26 disposed in the hollow portion. A servo motor 28 is provided. A toothed driven pulley 29 is attached to the front end of the screw coupling 27, and a toothed driving pulley 31 is attached to the rotor shaft 30 of the servo motor 28. Further, between the toothed driven pulley 29 and the toothed driving pulley 31. In addition, the rotation transmission mechanism is configured by spanning the timing belt 32. On the other hand, the rear end of the heating cylinder 11 is attached to the front end surface of the injection table 21. The heating cylinder 11 is provided with a hopper 34 at the rear, and a screw 2s (movable part 2) is inserted therein, and the rear end of the screw 2s is coupled to the center of the screw coupling 27 (toothed driven pulley 29).

  On the other hand, a bearing holding ring 35 is attached to the rear end of the front slider 24, and the outer ring portion of the load cell 36 is fixed to the rear end surface of the bearing holding ring 35 with a plurality of fixing screws. Further, four restriction stoppers 37 are attached to the bearing holding ring 35, and the rear slider 25 is restricted by the restriction stoppers 37. Each of the restriction stoppers 37 is not in contact with the load cell 36. On the other hand, the rear slider 25 is connected to the drive mechanism 1 and is driven forward and backward by the drive mechanism 1.

  Next, the structure of the drive mechanism 1 which becomes the principal part of the injection molding machine M according to the present embodiment will be described with reference to the drawings.

  First, the front end of the nut portion 6 in the ball screw mechanism 4 is fixed to the rear end surface of the rear slider 25 with a plurality of fixing screws. On the other hand, the injection drive base 22 has a hollow portion inside, and a bearing 51 disposed in the hollow portion rotatably supports the rear end shaft portion 52 of the ball screw portion 5 of the ball screw mechanism 4. Reference numeral 53 denotes a bearing holding ring fixed to the front end surface of the injection drive base 22.

  Further, as shown in FIG. 2, an attachment 55o is attached to the rear end surface of the injection drive base 22 by a plurality of fixing screws 54, and an injection servo motor is attached to the attachment 55o by a plurality of fixing screws 56. Install the basic servo motor 3o. The basic servo motor 3o includes a casing 60 formed of a non-magnetic material, and a non-magnetic rotor shaft 7o is rotatably supported in the casing 60 via a pair of front and rear bearings 61 and 62. Four magnets 63 arranged at equal intervals in the circumferential direction are fixed to the outer periphery of the rotor shaft 7o located inside the casing 60 to constitute a rotor portion (magnet rotor) 64 (see FIG. 3). In this case, the types and sizes of the magnets 63 are selected so that the magnetic flux density is as high as possible. In addition, 65 ... is a spacer provided between each magnet 63 ....

  On the other hand, a stator portion 66 is provided at a position facing the rotor portion 64 on the inner peripheral surface of the casing 60. The stator portion 66 has a yoke portion 67 configured in a cylindrical shape by laminating a large number of silicon steel plates formed in a ring shape, and is formed inside the yoke portion 67 at a constant pitch in the circumferential direction. It has many core parts 68 .... Then, a stator coil 69 is wound around (attached to) each core portion 68. At this time, the number (number of slots) of the core portions 68... Is increased as much as possible, and preferably set to 36 or more, so that a low-speed and high-torque rotation is output together with the high magnetic flux density by the magnets 63. A synchronous AC servo motor is configured.

  Further, the front end portion 7os of the rotor shaft 7o and the rear end portion 5s of the ball screw portion 5 (rear end shaft portion 52) of the ball screw mechanism 4 are directly connected using a direct connection mechanism 8 as shown in FIGS. . This direct coupling mechanism 8 includes a rear end portion 5s of the ball screw portion 5 inserted into a concave portion 15 formed in the axial direction from the end surface 7of of the rotor shaft 7o, and a relative portion of the ball screw portion 5 with respect to the rotor shaft 7o by the restriction portion 16. Regulate rotation. In this case, as shown in FIG. 3, the restricting portion 16 includes an axial groove 70 formed on the inner peripheral surface of the recess 15, an axial groove 71 formed on the outer peripheral surface of the rear end portion 5 s, A single parallel pin 72 straddling the concave groove 70 and the concave groove 71 is provided. Therefore, by using such a direct coupling mechanism 8, it is possible to avoid the direct coupling mechanism 8 from projecting outward from the outer diameter of the rotor shaft 7o. In addition, since the gain (control constant) can be increased by increasing the rigidity of the transmission system, the stability of the control can be increased, and the rotational output of low speed and high torque is directly transmitted, resulting in control responsiveness and control accuracy. In addition, the accuracy of control can be greatly improved.

  On the other hand, the attachment 55a is attached to the rear end surface of the casing 60, which is the rear end of the basic servo motor 3o, by means of fixing screws 54, and an additional servo motor which is a second servo motor is attached to the attachment 55a by means of the fixing screws 56. Install 3a. In this case, the additional servo motor 3a can be used by changing only a part (shape) of the same servo motor as the basic servo motor 3o. That is, normally, as shown in FIG. 2, a rotary encoder 57 for detecting the rotational speed (rotational speed) of the rotor section 64 is attached to the rear end of the servo motor. Therefore, the attachment 55 a can be used by changing a part of the shape of the encoder cover that covers the rotary encoder 57. Specifically, the function of the attachment 55o is added to the function of covering the rotary encoder 57, and a hole 55ah through which the rear end shaft portion 7or of the rotor shaft 7o is inserted is provided in the center of the attachment 55a.

  Further, the rear end shaft portion 7or of the rotor shaft 7o in the basic servo motor 3o protrudes through the hole 55ah, and the rear end shaft portion 7or and the front end portion 7as of the rotor shaft 7a in the additional servo motor 3a are shown in FIG. Thus, the direct connection mechanism 13a which comprises the rotation transmission means 9 connects. In this case, the configuration of the direct coupling mechanism 13a is the same as that of the direct coupling mechanism 8 in which the front end portion 7os of the rotor shaft 7o and the rear end portion 5s of the ball screw portion 5 of the ball screw mechanism 4 are directly coupled. For this reason, the same reference numerals are given to the same parts of the direct connection mechanism 13a as the direct connection mechanism 8 to clarify the configuration, and detailed description thereof is omitted.

  Further, a rotary encoder 57 for detecting the rotational speed (rotational speed) of the rotor portion 64 is attached to the rear end surface of the casing 60 in the additional servo motor 3 a. The rotary encoder 57 is covered with an encoder cover 58. In this case, the configuration of the rotary encoder 57 itself of the additional servo motor 3a is the same as that of the rotary encoder 57 of the basic servo motor 3o. The rotary encoders 57 attached to the basic servo motor 3o and the additional servo motor 3a are particularly configured with high resolution so that they can be accurately detected even when the rotational speed of the rotor portions 64 is low. In other words, the number of pulses obtained per rotation of the rotor unit 64 is configured to be as large as possible. Specifically, 20,000 pulses or more per revolution, ideally 40,000 pulses or more are desirable. The rotary encoder 57 need only be attached to either one, but in the illustrated example, it is attached to both the servomotors 3o and 3a, so that not only the detection result of one but also the average value obtained from both detection results is used. It is also possible to do.

  Next, the operation | movement in the injection process of the injection molding machine M which concerns on this embodiment is demonstrated with reference to FIGS.

  Now, it is assumed that the injection molding machine M is in a state where the weighing process has been completed. Accordingly, the screw 2s is located at the reverse injection start position. By starting the injection process, the two servo motors 3o and 3a are simultaneously driven and controlled by a molding machine controller (not shown), and the rotor shafts 7o and 7a rotate together. In this case, the control conditions for the two servo motors 3o and 3a are the same. Then, the rotation of the rotor shaft 7o is transmitted to the ball screw portion 5 of the ball screw mechanism 4, and the nut portion 6 advances by the rotation of the ball screw portion 5. As a result, since the slider 25, the load cell 36, the bearing holding ring 35, the front slider 24, and the screw coupling 27 move forward together after the nut portion 6 is attached, the screw 2s also moves forward and is measured in front of the screw 2s. The resin is injected and filled into the mold.

  At this time, since the screw position and the injection speed when the screw 2s moves forward are detected by the rotary encoders 57 with high resolution, the screw position and the injection speed are controlled accurately and with high accuracy. Further, since the nut portion 6 in the injection process pressurizes the inner ring portion of the load cell 36 via the rear slider 25, pressure control such as injection pressure and holding pressure is performed based on the pressure detected from the load cell 36. At this time, the rear slider 25 only comes into contact with the load cell 36, and the rear slider 25 is loaded on the guide shafts 23, so that the rotation applied from the ball screw portion 5 to the nut portion 6 is performed. The directional stress (load) is received by the rear slider 25, and no problem is imparted to the load cell 36. Thereby, accurate and highly accurate pressure detection can be performed.

  Therefore, according to the injection molding machine M according to this embodiment, the additional servo motor 3a is mounted in addition to the basic servo motor 3o, and the rotor shaft 7o of the basic servo motor 3o and the rotor shaft of the additional servo motor 3a are mounted. 7a is connected by the direct connection mechanism 13a (rotation transmission means 9), and therefore the end portion 5s of the ball screw portion 5 of the ball screw mechanism 4 and the end portion 7os of the rotor shaft 7o of the basic servo motor 3o are connected by the direct connection mechanism 8. Even in this case, a high output can be easily secured, and an increase in the size of the basic servo motor 3o itself and an increase in cost can be avoided. In the case of the example, since the screw 2s inserted into the heating cylinder 11 of the injection device Mi is applied to the movable part 2, it is possible to avoid an increase in size and cost of the injection device Mi, and in particular, accuracy and stability related to the control of the injection process. It can contribute to the improvement of sex.

  By the way, in the injection molding machine M according to the present embodiment, since the two servo motors 3o and 3a are connected, only one servo motor 3o (or 3a) can be used. Therefore, according to the molding process and molding conditions, a single mode using only one servo motor 3o (or 3a) and a multiple mode using both servo motors 3o at the same time can be selected. For example, a single mode can be used for the filling process, and a multiple mode can be used for the pressure holding process. In the case of the single mode, a back electromotive force is generated in the other servo motor 3a (or 3o) that is not supplied with power. Therefore, it is necessary to provide a power absorption circuit or the like to prevent braking.

  Next, an injection molding machine M according to a modified embodiment of the present invention will be described with reference to FIGS. 4 to 7 show a modified embodiment of the rotation transmission means 9 for connecting the servomotors 3o, 3a,... FIG.

  First, the injection molding machine M shown in FIG. 4 uses, as the rotation transmission means 9, a rotation transmission mechanism 14a that transmits rotation by being interposed between the rotor shaft 7o of the basic servo motor 3o and the rotor shaft 7a of the additional servo motor 3a. This is different from the injection molding machine M shown in FIG. The rotation transmission mechanism 14a fixes the transmission gear 81 to the rear end shaft portion 7or of the rotor shaft 7o, and fixes the transmission gear 82 to the end portion (front end portion) 7as of the rotor shaft 7a. An intermediate gear 83 is disposed between the transmission gear 82 and the gear transmission mechanism. In this way, when connecting the basic servo motor 3o and the additional servo motor 3a, if the rotor shafts 7o and 7a are connected by the rotation transmission mechanism 14a, the degree of freedom of design for the layout of the additional servo motors 3a is increased. Therefore, there is an advantage that it is possible to contribute to the downsizing of the entire injection molding machine M (drive mechanism 1).

  Further, when the basic servo motor 3o and the additional servo motor 3a are connected to each other, the injection molding machine M shown in FIG. 5 connects the rotor shafts 7o and 7a with the rotation transmission mechanism 14b (rotation transmission means 9). The difference from the modified embodiment shown in FIG. 4 is that the mounting position of the motor 3a is different from the type and connection position of the rotation transmission mechanism 14b. When mounting the additional servo motor 3 a, the rotation transmission mechanism 14 b attaches an attachment member 91 to the upper surface of the injection drive base 22 and installs the additional servo motor 3 a on the attachment member 91. The transmission pulley 92 is fixed to the end portion (front end portion) 7as of the rotor shaft 7a of the additional servo motor 3a, the transmission pulley 93 is fixed to the rear end shaft portion 52 of the ball screw portion 5, and the transmission pulley 93 and a transmission pulley 92, a timing belt 94 is bridged to constitute a belt transmission mechanism. In this way, when connecting the basic servo motor 3o and the additional servo motor 3a, if they are connected by the rotation transmission mechanism 14b, the design freedom for the layout of the additional servo motors 3a... Is similar to the modified embodiment shown in FIG. Since the degree can be increased, there is an advantage that it is possible to contribute to the miniaturization of the entire injection molding machine M (drive mechanism 1).

  Further, the injection molding machine M shown in FIG. 6 is a combination of the embodiment shown in FIG. 1 and the modified embodiment shown in FIG. 4, and two additional servos for the basic servo motor 3o. The motors 3a and 3b are mounted, the basic servo motor 3o and the additional servo motor 3a are connected by the rotation transmission mechanism 14a shown in FIG. 4, and the additional servo motors 3a and 3b are connected directly by the direct connection mechanism shown in FIG. 13a is connected. As described above, a plurality of additional servo motors 3a and 3b can be coupled to the basic servo motor 3o. In particular, if the direct coupling mechanism 13a and the rotation transmission mechanism 14a are connected in combination, a plurality of servo motors 3o and 3a are connected. Can be laid out flexibly and can contribute to the miniaturization of the entire injection molding machine M (drive mechanism 1). In addition, by adding selectivity to the plurality of servo motors 3o, 3a... And the rotation transmission means 9, accurate and flexible molding corresponding to various molded products can be easily performed, and a wider control range. Can contribute to improvement of accuracy and stability.

  On the other hand, the injection molding machine M shown in FIG. 7 is based on the injection molding machine M shown in FIG. 1 and has a clutch mechanism 101 interposed between the basic servo motor 3o and the additional servo motor 3a. The single mode using only one servo motor 3o and the multiple mode using both servo motors 3o at the same time can be selected not only electrically but also mechanically. The power absorption circuit provided in the other servo motor 3a that does not supply power is not required. In FIG. 7, reference numeral 102 denotes a support base for supporting the basic servo motor 3o and the additional servo motor 3a.

  Further, the injection molding machine M shown in FIG. 8 uses a movable member 2m that moves the movable mold Cm in the mold clamping mechanism 12 of the mold clamping device Mc as the movable part 2. In this case, since the mold clamping mechanism 12 is configured by the toggle link mechanism L, the movable member 2m that is directly driven by the drive mechanism 1 becomes the crosshead 2h of the toggle link mechanism L. In this case, the illustrated mold clamping device Mc includes a fixed platen 112 and a pressure platen 113 that are spaced apart from each other. The fixed platen 112 is fixed on a machine base (not shown), and the pressure platen 113 is mounted on the machine base. It is supported so that it can move forward and backward. Four tie bars 114 are installed between the fixed platen 112 and the pressure receiving plate 113. The front ends of the tie bars 114 are fixed to the stationary platen 113, and the rear ends of the tie bars 114 are inserted into the pressure receiving plate 113. On the other hand, the movable plate 115 is slidably loaded on the tie bars 114. The movable plate 115 supports the movable mold Cm, the fixed plate 113 supports the fixed mold Cc, and the movable mold Cm and the fixed mold Cc constitute a mold C. Further, a toggle link mechanism L is disposed between the pressure receiving plate 113 and the movable platen 115. The toggle link mechanism L includes a pair of first links La and La pivotally supported on the pressure receiving plate 113, a pair of output links Lc and Lc pivotally supported on the movable plate 115, the first links La and La and the output links Lc, A pair of second links Lb and Lb are coupled to the support shaft of Lc, and the second links Lb and Lb are pivotally supported on the cross head 2h. Further, the drive mechanism 1 is disposed between the pressure receiving plate 113 and the cross head 2h. In this case, the drive mechanism 1 is the same as the drive mechanism 1 shown in FIG. In FIG. 8, reference numeral 116 denotes a mold thickness adjusting unit. By applying to such a mold clamping mechanism 12 (mold clamping device Mc), in particular, an increase in size and cost of the mold clamping device Mc can be avoided, and accuracy and stability relating to control of the mold clamping process can be improved. Can contribute.

  4 to 8, the same components as those in FIGS. 1 to 3 are denoted by the same reference numerals to clarify the configuration, and detailed description thereof is omitted.

  Although various embodiments have been described in detail above, the present invention is not limited to such embodiments, and the detailed configuration, shape, material, quantity, and the like are within the scope not departing from the gist of the present invention. , Can be changed, added and deleted arbitrarily.

  For example, although the screw 2s of the injection device Mi and the movable member 2m of the mold clamping device Mc are illustrated as the movable portion 2, an ejector pin or the injection device itself may be used. On the other hand, the direct coupling mechanism 8 has the recess 15 formed in the end surface 7of of the rotor shaft 7o, but a recess is formed in the end of the ball screw part 5 or the nut part 6, and the end of the rotor shaft 7o is inserted into this recess. May be. Moreover, although the illustrated structure is suitable for the direct connection mechanism 8, it does not exclude use of a direct connection mechanism having another structure, for example, spline coupling. Further, the ball screw mechanism includes a so-called roller screw mechanism. On the other hand, as is apparent from FIGS. 1 and 4 to 7, the number of additional servomotors 3 a connected to the basic servomotor 3 o, rotation transmission means, and combinations can be arbitrarily implemented.

A partial cross-sectional side view of an injection device in an injection molding machine according to the best embodiment of the present invention, Cross-sectional side view of servo motor (drive mechanism) used in the injection device, Cross-sectional front view showing a part of a servo motor used in the injection device, The plane block diagram which shows a part of injection device in the injection molding machine which concerns on the modified embodiment of this invention, A partially sectional side view showing a part of an injection device in an injection molding machine according to another modified embodiment of the present invention, The plane block diagram which shows a part of injection device in the injection molding machine which concerns on other modified embodiment of this invention, A partially sectional side view showing a part of an injection device in an injection molding machine according to another modified embodiment of the present invention, The plane block diagram which shows the mold clamping apparatus in the injection molding machine which concerns on other modified embodiment of this invention,

Explanation of symbols

  1: drive mechanism, 2: movable part, 2s: screw, 2m: movable member, 3o: basic servo motor, 3a ...: additional servo motor, 4: ball screw mechanism, 5: ball screw part, 5s: ball screw part End, 6: Nut, 7o: Rotor shaft, 7os: End of rotor shaft, 7a ...: Rotor shaft, 7as: Front end of rotor shaft, 8: Direct coupling mechanism, 9: Rotation transmission means, 11: Heating cylinder , 12: Clamping mechanism, 13a ...: Direct coupling mechanism, 14a ...: Rotation transmission mechanism, 15: Recess, 16: Restriction part, 55a: Attachment, 60: Casing, Cm: Movable mold, M: Injection molding machine, Mi: Injection device, Mc: Clamping device

Claims (4)

  A drive mechanism that drives the movable portion forward and backward by a servo motor and a ball screw mechanism, and an end portion of a ball screw portion or a nut portion of the ball screw mechanism that moves the movable portion forward and backward, and a front end portion of the rotor shaft of the servo motor In addition to the servo motor (basic servo motor), another servo motor (additional servo motor) is mounted on the injection molding machine that is connected by a direct coupling mechanism, and an attachment is attached to the rear end surface of the casing of the basic servo motor. The additional servo motor is attached, and an axial concave portion is provided on one end surface of the rear end portion of the rotor shaft of the basic servo motor or the front end portion of the rotor shaft of the additional servo motor. Insert the other, and between the inner peripheral surface of the recess and the outer peripheral surface facing the inner peripheral surface By providing a rotation transmitting means for connecting a rotor shaft of the basic servo motor and a rotor shaft of the additional servo motor by a direct coupling mechanism, a restricting portion that restricts counter rotation is provided to the rotor shaft of the basic servo motor. An injection molding machine characterized in that the rotation of the rotor shaft of the additional servo motor can be transmitted.   The injection molding machine according to claim 1, wherein the movable part is a screw inserted into a heating cylinder of an injection device.   The injection molding machine according to claim 1, wherein the movable part is a movable member that moves the movable mold forward and backward in the mold clamping mechanism of the mold clamping device.   A drive mechanism that drives the movable portion forward and backward by a servo motor and a ball screw mechanism, and an end portion of a ball screw portion or a nut portion of the ball screw mechanism that moves the movable portion forward and backward, and a front end portion of the rotor shaft of the servo motor In an injection molding machine that is connected by a direct coupling mechanism, in addition to the servo motor (basic servo motor), another servo motor (additional servo motor) is mounted, and the end of the rotor shaft that protrudes outside the basic servo motor And a rotor transmission shaft using a gear transmission mechanism or a belt transmission mechanism between the end portion of the rotor shaft projecting outside the additional servo motor and the rotor shaft of the basic servo motor. An injection component characterized in that the rotation of the rotor shaft of the additional servo motor can be transmitted. Machine.

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