JP2020037213A - Two plate-type injection device - Google Patents

Abstract

To provide a two plate type injection device which facilitates attachment/detachment of a ring type load cell without increasing a weight and an inertial moment of a moving member including a moving plate.SOLUTION: In a two plate type injection device 10, ball screw shafts 20a and 21a of a pair of ball screw mechanisms 20 and 21 are supported by a fixation plate 2 in a rotatable manner, ball screw nuts 20b and 21b combined with the ball screw shafts 20a and 21a are stored in ball screw nut storage through holes 3a and 3b longitudinally passing through a moving plate 3, and at least one ball screw nut is supported by the moving plate 3 via a ring type load cell fixed to the rear part of the moving plate 3 in a state of being stored in the ball screw nut storage through holes.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a two-plate injection device used for injection molding.

  The in-line screw type injection device of the injection molding machine includes a fixed plate, a movable plate provided so as to be able to advance and retreat with respect to the fixed plate, a screw supported by the movable plate so as to be rotatable about an axis, and A screw barrel rotatably provided with a cylinder barrel accommodated so as to be able to advance and retreat in the axial direction, and by moving the movable plate forward and backward with respect to the fixed plate, the screw is rotatable within the cylinder barrel and is capable of moving forward and backward. It is an injection device.

  The above-described in-line screw type injection devices are roughly classified into two types according to a configuration in which the movable plate can move forward and backward with respect to the fixed plate. One is a two-plate injection device as disclosed in Patent Literature 1 and Patent Literature 2. The two-plate injection device includes a driving unit (electric motor or the like) for moving the moving plate relative to the fixed plate and a driving unit (electric motor or the like) for rotating the screw. A configuration in which a moving plate advancing / retracting mechanism such as a ball screw mechanism or the like is arranged therebetween is mainly used.

  The other is a three-plate injection device. In the three-plate injection device, a fixed plate and a rear plate are connected by a plurality of connecting members such as tie bars, and a movable plate disposed between the two plates so as to be able to advance and retreat is provided between the fixed plate (or the movable plate) and the rear plate. The mainstream configuration is to move the moving plate with respect to the fixed plate by a moving plate moving mechanism such as a ball screw mechanism arranged in the moving plate.

  The former two-plate injection device does not require a rear plate, and the movable plate advance / retreat mechanism is disposed between the fixed plate and the movable plate. Therefore, the overall length of the injection device can be shorter than that of the latter three-plate injection device. . Therefore, it is adopted when there is a restriction on a small injection device or an installation space of an injection molding machine. On the other hand, a three-plate type injection device is often employed especially when there are no restrictions on the size of the injection device or the above-described restrictions on the installation space.

  In addition, in the in-line screw type injection apparatus, the resin material (pellet) supplied from the resin material supply unit such as a hopper at the rear of the injection apparatus is rotated regardless of the two-plate type or the three-plate type by rotating the screw into a cylinder barrel. A measuring step is performed in which the molten resin is melted (plasticized) while flowing into the storage section at the front end (front), and the molten resin necessary for one injection filling step is stored in the storage section. In this measuring step, a predetermined pressure (back pressure) is applied to the molten resin in the storage section.

  After the completion of the measuring step, an injection filling step is performed in which the molten resin stored in the storage section is filled in the mold at a stretch by moving the screw forward. To control the back pressure in these measuring processes and the injection pressure in the injection filling process, the axial force of the screw acting on the rotating shaft of the screw and the components of the moving plate advance / retreat mechanism is used as the molten resin pressure in the storage section. A resin pressure measuring means for measuring is arranged.

  When the driving means for moving the moving plate relative to the fixed plate or the driving means for rotating the screw is a servomotor, use the torque measurement / control function of the servomotor to replace the resin pressure measurement means. It is also possible. On the other hand, the resin pressure measuring means for directly measuring the axial force of the screw acting on the screw rotating shaft and the components of the moving plate advance / retreat mechanism can more accurately measure the molten resin pressure in the storage section. It has been.

  For example, both the injection devices of Patent Literature 1 and Patent Literature 2 are two-plate type injection devices, and a ball screw mechanism is adopted as a moving plate advance / retreat mechanism. The injection device disclosed in Patent Document 1 discloses a form in which a ball screw nut of the ball screw mechanism is supported on a fixed plate via a load cell serving as a resin pressure measuring means (Patent Document 1 / FIG. 1). ). Further, the injection device disclosed in Patent Document 2 discloses a form in which a ball screw nut of the ball screw mechanism is supported on a moving plate via a load cell serving as a resin pressure measuring means (Patent Document 2 / FIG. 2). ).

JP-A-2017-094681 JP 2012-196828 A

  The load cell employed as the pressure measuring means generally has a configuration in which the amount of elastic deformation of the load cell itself in the pressure receiving direction is measured by a built-in strain measuring means such as a strain gauge. The pressure receiving direction includes a compression type, a tension type, a dual-purpose type, and the like, and is appropriately selected depending on a pressure measured at a place where the load cell is arranged and an action direction thereof. On the other hand, the load cell adopted as the resin pressure measuring means of the injection device has a disk-like shape having an opening penetrating in the thickness direction at the center portion in consideration of the mounting location as in Patent Document 1 or Patent Document 2, and has a pressure receiving pressure. In many cases, the direction is the same disk-shaped thickness direction. These shapes are called a ring or a washer, but in the present application, they are called a ring type load cell.

  In the injection device of Patent Literature 1 (Patent Literature 1 / FIG. 1), a ball screw nut combined with a ball screw shaft is housed in a through hole penetrating a fixing plate back and forth, and the ball screw nut is connected to the through hole. Is supported by the fixed plate via a ring-type load cell fixed in front of the fixed plate. For example, when the ball screw shaft is rotated by the injection motor on the moving plate side to move the moving plate (screw) forward or backward, the ball screw shaft moves through the opening of the ring type load cell as the moving plate moves forward or backward. Move forward and backward with respect to the fixed plate. The molten resin pressure in the storage section in the measuring step or the injection filling step acts on the ring type load cell fixed to the fixed plate via the screw, the moving plate, the ball screw shaft and the ball screw nut, so that the pressure is measured.

  In the injection device of Patent Document 2 (Patent Document 2 / FIG. 2), a ball screw nut combined with a ball screw shaft projects rearward via a ring-type load cell fixed behind a moving plate. Supported on a moving plate. For example, when the ball screw shaft is rotated by the injection motor on the fixed plate side to move the moving plate (screw) and the ball screw nut forward or backward, the ball screw shaft screwed into the ball screw nut closes the opening of the ring type load cell. Since it rotates while penetrating, it does not hinder the forward and backward movement of the moving plate. The molten resin pressure in the storage section in the measuring step or the injection filling step acts on the ring type load cell fixed to the moving plate via the screw, the moving plate, and the ball screw nut, so that the pressure is measured.

  In the injection device of Patent Literature 1, the ring-type load cell can be removed without removing the ball screw nut from the ball screw shaft by disposing the ring-type load cell as described above (see Patent Literature 1). Paragraph [0038], etc.). However, in this configuration, it is difficult to rotationally drive both the ball screw nut and the ball screw shaft on the fixed plate side. As a result, the injection motor must be attached to the moving plate, and both the injection motor and the metering motor for rotating the screw are arranged on the moving plate. For this reason, in the case where the injection motor is disposed on the fixed plate and the weighing motor is disposed on the moving plate as in the injection device of Patent Document 2, the movement that moves forward and backward with respect to the fixed plate during the weighing process and the injection filling process is performed. Since the weight of the moving member including the plate and the moment of inertia of the moving member increase, it affects the back pressure during the screw retreat operation during the weighing process and the controllability of the screw injection speed and injection pressure during the injection filling process. give.

  On the other hand, as long as the injection device can be firmly fixed and supported on a foundation or the like, this effect and vicious circle can be suppressed to some extent. However, in the case of a configuration in which a sub injection device different from the main injection device is fixed to a mold clamping device (fixed plate or movable plate, etc.) or a mold of an injection molding machine in various mounting postures such as vertical or horizontal fixation. In addition, the ratio of the weight of the moving member or the moment of inertia to the total weight of the injection device must be larger than the ratio of the main injection device. This tendency becomes more remarkable as the injection device becomes smaller, and the influence on the control of the back pressure in the measuring step and the controllability of the injection speed and injection pressure in the injection filling step cannot be ignored. Also, due to restrictions on the support form of the injection device, it may be difficult to secure the support rigidity for supporting the weight and the moment of inertia of these moving members without affecting the controllability of the injection device.

  On the other hand, in the injection device of Patent Literature 2, the ring-type load cell cannot be removed from the rear of the moving plate without removing the ball screw nut from the ball screw shaft due to the arrangement of the ring-type load cell as described above. Generally, if the ball screw nut is removed from the ball screw shaft as it is, the ball in the ball screw nut falls off and becomes unusable. Therefore, when removing the ball screw nut from the ball screw shaft, a special removal jig (temporary shaft, sleeve, etc.) is required. That is, in the injection device of Patent Literature 2, when the ring-type load cell is removed from the rear of the moving plate or newly attached, the ball screw nut is removed from the ball screw shaft using a dedicated removal jig, It is necessary to remove the complete ball screw mechanism including the ball screw shaft and the ball screw nut from the injection device. As a result, there is a problem that it takes time and effort to attach and detach the ring-type load cell to and from the injection device for maintenance or replacement due to failure.

  The present invention has been made in view of the above-described problems, and provides a two-plate injection device in which a ring-type load cell can be easily attached and detached without increasing the weight and the moment of inertia of a moving member including a moving plate. The purpose is to do.

The object of the present invention is to provide a fixed plate, a cylinder barrel disposed in front of the fixed plate, a movable plate provided behind the fixed plate so as to be able to advance and retreat with respect to the fixed plate, A pair of ball screw mechanisms for moving the screw back and forth with respect to the fixed plate, an injection motor for driving the pair of ball screw mechanisms, a screw rotatably supported on the movable plate about an axis, and the screw A two-plate injection device, comprising a weighing motor that rotates the screw, by moving the movable plate forward and backward with respect to the fixed plate, so that the screw can advance and retract within the cylinder barrel.
Ball screw shafts of the pair of ball screw mechanisms are rotatably supported by the fixed plate, respectively.
Ball screw nuts combined with the ball screw shaft are respectively housed in ball screw nut housing through holes that penetrate the moving plate back and forth,
At least one of the ball screw nuts is supported by the moving plate via a ring type load cell fixed to the rear of the moving plate in a state housed in the ball screw nut housing through hole. This is achieved by a two-plate injection device.

  Such a two-plate injection device is characterized in that the ball screw shaft end portion penetrated into the cylinder barrel side of the fixed plate, and a ball between at least one output shaft of the injection motor disposed on the fixed plate. It is preferable that a screw shaft rotation transmitting means is arranged and the ball screw shaft is rotated.

The two-plate injection device according to the present invention includes a fixed plate, a cylinder barrel disposed in front of the fixed plate, and a movable plate provided behind the fixed plate so as to be able to advance and retreat with respect to the fixed plate. A pair of ball screw mechanisms for moving the movable plate relative to the fixed plate, an injection motor for driving the pair of ball screw mechanisms, and a screw supported by the movable plate so as to be rotatable about an axis. And a metering motor that rotates the screw, a two-plate injection device that allows the screw to move forward and backward in the cylinder barrel by moving the moving plate forward and backward with respect to the fixed plate,
Ball screw shafts of the pair of ball screw mechanisms are rotatably supported by the fixed plate, respectively.
Ball screw nuts combined with the ball screw shaft are respectively housed in ball screw nut housing through holes that penetrate the moving plate back and forth,
Since at least one of the ball screw nuts is stored in the ball screw nut storage through hole and supported by the moving plate via a ring-type load cell fixed behind the moving plate, the moving plate The ring-type load cell can be easily attached and detached without increasing the weight and the moment of inertia of the moving member including.

FIG. 2 is a schematic plan view of the two-plate injection device according to the first embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
A two-plate injection device according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic plan view (including a partial cross section) of a two-plate injection device according to the first embodiment, showing a state in which a screw 4 and a movable plate 3, which will be described later, are at a retreat limit position (a measurement completion position). Show. In FIG. 1, a part of the screw 4 and the movable plate 3 at the forward limit position (injection completion position) are shown by two-dot chain lines. The left side of FIG. 1 is the front, the right side is the rear, and the near side of FIG. 1 is the upper side. Although FIG. 1 is referred to as a plan view, an illustration suitable for describing the configuration of the two-plate injection device according to the first embodiment of the present invention is referred to as a plan view. The two-plate type injection device is not called a plan view based on the mounting posture of the two-plate injection device to the injection molding machine. The two-plate injection device according to the present invention may be attached to the injection molding machine in a vertical, horizontal, or other various mounting posture with respect to the axial direction in which the screw is rotated.

  As shown in FIG. 1, a two-plate injection device 10 according to a first embodiment of the present invention includes a fixed plate 2, a cylinder barrel 11 disposed in front of the fixed plate 2, and a rear of the fixed plate 2. The movable plate 3 is provided so as to be capable of moving forward and backward with respect to the fixed plate 2, a pair of ball screw mechanisms 20 and 21 for moving the movable plate 3 toward and away from the fixed plate 2, and a pair of ball screw mechanisms 20 and 21 are driven. It includes an injection motor 31, 32, a screw 4 supported on the movable plate 3 in a rotatable state about an axis by a screw rotation supporting portion 4a, and a metering motor 41 for rotating the screw 4 about the axis. ing.

  The screw rotation supporting portion 4a may employ a radial bearing, a thrust bearing, or a known rotation supporting form in which a plurality of the respective bearings are combined. In addition, in consideration of screw attachment and detachment at the time of maintenance and replacement of the screw 4, the rotation shaft portion rotatably supported by the screw rotation support portion 4 a is formed separately from the rotation shaft portion of the screw 4, and both rotation shaft portions are configured to be detachable. May be. As the guide mechanism for moving the movable plate 3 toward and away from the fixed plate 2, a well-known guide mechanism such as a linear guide disposed on the base member or a guide rod standing upright from the fixed plate is employed. Just do it. In order to simplify the drawing, the illustration of such a base member and a guide mechanism is omitted.

  Then, the ball screw shafts 20a and 21a of the pair of ball screw mechanisms 20 and 21 are rotatably supported on the fixed plate 2 by the ball screw shaft rotation support portions 24, respectively, and are combined with the ball screw shafts 20a and 21a. The nuts 20b and 21b are housed in the ball screw nut housing through holes 3a and 3b respectively penetrating the moving plate 3 back and forth, and the ball screw nuts 20b and 21b are housed in the ball screw nut housing through holes 3a and 3b. In this state, the movable plate 3 is supported by the movable plate 3 via ring-type load cells 50 and 51 fixed behind the movable plate 3.

  Specifically, the ring-type load cells 50 and 51 are not shown from the rear (rear surface) of the movable plate 3 which has been internally threaded in advance corresponding to the fixed position via bolt holes formed on the outer peripheral side. It is fixed with bolts. On the other hand, on the rear side (rear surface) of the ball screw nuts 20b and 21b, female threads corresponding to the bolt holes formed on the inner peripheral side of the ring type load cells 50 and 51 are formed in advance. The rear side (rear side) is fixed to the front side (front side) of the ring type load cells 50, 51 from the rear side (rear side) of the ring type load cells 50, 51 with bolts (not shown). As a result, the ball screw nuts 20b and 21b are stored in the ball screw nut storage through-holes 3a and 3b, and are attached to the movable plate 3 via the ring type load cells 50 and 51 fixed behind the movable plate 3. Supported.

  Further, between the end portions of the ball screw shafts 20 a and 21 a penetrating the fixed plate 2 toward the cylinder barrel 11 and the output shafts of the injection motors 31 and 32 disposed on the fixed plate 2, ball screw shaft rotation transmitting means 31 a. 32a are arranged, and the ball screw shafts 20a and 21a are driven to rotate. In the first embodiment, a ball screw shaft rotation transmitting means 31a, 32a is connected to a pulley disposed on an end of the ball screw shafts 20a, 21a, an output shaft of the injection motors 31, 32, and a belt connecting between the pulleys. However, the present invention is not limited to this, and a known rotation transmitting unit may be employed. Further, in FIG. 1, the injection motors 31 and 32 are illustrated as being disposed at both ends above the fixed plate 2 in order to avoid overlapping of the illustrated configuration. May be arranged side by side in the center above, or may be arranged so as to penetrate through the fixed plate 2 instead of above the fixed plate 2.

  Here, a screw shaft rotation transmitting means 4b for transmitting a rotational motion to the shaft of the screw 4 is disposed in front of the moving plate 3. In the first embodiment, the screw shaft rotation transmitting means 4b is a combination of a pulley arranged on the shaft of the screw 4, an output shaft of the weighing motor 41 (not shown), and a belt for connecting the two pulleys. Instead, a known rotation transmitting unit may be employed. The metering motor 41 may be arranged at any position on the moving plate 3 as long as the screw 4 can be driven to rotate via the screw shaft rotation transmitting means 4b. Directly above the axis is preferred. In FIG. 1, in order to avoid duplication of the illustrated configuration, the illustration of the metering motor 41 and the pulley of the output shaft of the motor is omitted, and only a part of the pulley and the belt arranged on the shaft of the screw 4 are illustrated. ing.

  Next, in the two-plate type injection device 10 according to the first embodiment of the present invention, the ring type load cells 50 and 51 are used to control the back pressure in the measuring step and the storage necessary for controlling the injection pressure in the injection filling step. The measurement of the molten resin pressure of the portion will be described.

  First, in the measuring step, with the increase in the volume of the molten resin in the storage section, the screw on which the molten resin pressure acts rearward was retracted to apply a predetermined pressure (back pressure) to the molten resin in the storage section. In this state, the molten resin required for one injection filling step is stored in the storage section.

  Then, in the injection filling step, the ball screw shafts 20a, 21a are rotationally driven by the injection motors 31, 32, and the moving plate 3 is moved toward the fixed plate 2 via the ball screw nuts 20b, 21b and the ring type load cells 50, 51. Advance in the approaching direction. At this time, the screw moving forward pushes out (injects) the molten resin in the storage section forward (die) from the nozzle side in front of the cylinder barrel 11 and receives the reaction force (injection pressure). This reaction force acts on the ball screw nuts 20b and 21b as forward resistance through the moving plate 3 and the ring type load cells 50 and 51. That is, the ball screw nuts 20b and 21b exert a pulling force to pull the ring type load cells 50 and 51 forward (to the left in FIG. 1). This tensile force is measured as the pressure of the molten resin stored in the storage section at the tip of the cylinder barrel 11. In the measuring step, the pressure of the molten resin (predetermined back pressure) stored in the storage portion at the tip of the cylinder barrel 11 is measured by the ring type load cells 50 and 51 via the ball screw nuts 20b and 21b.

  As described above, in the two-plate injection device 10 according to the first embodiment of the present invention, the ball screw nuts 20b and 21b are housed in the ball screw nut housing through holes 3a and 3b penetrating the moving plate 3 back and forth. In this state, it is supported by the moving plate 3 via ring-type load cells 50 and 51 fixed to the rear of the moving plate. Therefore, the ring type load cells 50, 51 are arranged at the rearmost position of the two-plate injection device 10, and the ring type load cells 50, 51 can be easily attached and detached without removing the ball screw nuts 20b, 21b from the ball screw shafts 20a, 21a. .

  On the other hand, also in the injection device of Patent Document 2, the ring type load cell is arranged behind the moving plate. However, since the ring type load cell is disposed between the moving plate and the ball screw nut, the ring type load cell cannot be removed from the rear of the moving plate without removing the ball screw nut from the ball screw shaft.

  In addition, in the two-plate injection device 10 according to the first embodiment of the present invention, the injection motors 31 and 32 can be arranged on the fixed plate 2 instead of the movable plate 3, so that the injection device of Patent Document 1 can be used. Thus, at the time of the weighing step and the injection filling step, the weight of the moving member including the moving plate that moves forward and backward with respect to the fixed plate and the moment of inertia of the moving member can be reduced. With this configuration, it is not necessary to increase the weight and the moment of inertia of the moving member including the moving plate, and the back pressure at the time of the screw retreating operation during the weighing process and the controllability of the screw injection speed during the injection filling process are excellent. Also, the output required for the injection motor can be suppressed.

  Here, in the two-plate injection device 10 according to the first embodiment of the present invention, as described in the first embodiment, the screw shaft rotation transmitting means 4b for transmitting the rotational motion to the shaft of the screw 4 moves. By being arranged in front of the plate 3, the ring-type load cells 50 and 51 are arranged at the rearmost position of the two-plate injection device 10, and the attachment and detachment of the ring-type load cells 50 and 51 are facilitated. On the other hand, although not shown, the shaft of the screw 4 is penetrated to the rear of the moving plate 3, and the screw shaft rotation transmitting means 4b is disposed in the penetrating portion, that is, the screw shaft rotation transmitting means 4b Even if the screw shaft rotation transmitting means 4b (pulley, belt, or the like) is arranged behind the plate 3, the screw type rotation transmitting means 4b is arranged so as not to hinder the ring type load cells 50, 51 from being detached behind. Thus, the ease of attaching and detaching the ring type load cells 50 and 51 is ensured.

  Furthermore, in the two-plate injection device 10 according to the first embodiment of the present invention, the ball screw nuts 20b and 21b are housed in the ball screw nut housing through holes 3a and 3b penetrating the moving plate 3 back and forth. In this state, it is supported by the moving plate 3 via the ring type load cell. For this reason, the ring type load cell is disposed behind the moving plate (between the moving plate and the ball screw nut) and the ball screw nut is supported so as to protrude to the rear thereof. When the moving stroke of the (moving plate 3) is the same, the total length of the two-plate type injection device can be reduced by at least the total length of the ball screw nut, and accordingly, the total length of the ball screw shaft can be reduced. This is a sub-injection device separate from the main injection device. The smaller the injection device, the more the injection device of Patent Document 1 has the weight and moment of inertia of the moving member with respect to the total weight of the injection device. This is a mode suitable for securing the support rigidity of the injection device by suppressing an increase in the ratio of the injection device, and can also be expected to reduce the cost of the injection device.

  As described above, the first embodiment and another related embodiment have been described as to the embodiments for carrying out the invention. However, the invention is not limited to the above-described embodiments, and is described in the claims. It goes without saying that the present invention can be implemented in various forms without departing from the scope of the present invention.

  For example, in the two-plate injection device 10 according to the first embodiment of the present invention, both the ball screw nuts 20 b and 21 b of the ball screw mechanisms 20 and 21 are connected to the moving plate 3 via the ring type load cells 50 and 51. The supported form has been described. However, although not shown, only one ball screw nut may be supported by the moving plate 3 via the ring type load cell. In this case, the other ball screw nut is supported by the moving plate 3 via a dummy load cell having the same shape as the ring type load cell. Since the ball screw mechanisms 20 and 21 are basically arranged in parallel with and at the same distance from the axis of the screw 4, the axial force of the screw 4 acting on each of the ball screw mechanisms may be regarded as equal. . Therefore, the pressure measured by the ring type load cell on one ball screw nut side may be doubled to obtain the molten resin pressure in the storage section.

  Alternatively, in the two-plate injection device 10 according to the first embodiment of the present invention, the fixed plate 2 is disposed on the end portions of the ball screw shafts 20 a and 21 a penetrating the cylinder barrel 11 side and the fixed plate 2. The embodiment in which the ball screw shaft rotation transmitting means 31a and 32a are arranged between the output shafts of the injection motors 31 and 32 and the ball screw shafts 20a and 21a are driven to rotate has been described. However, as described above, it is not always necessary that each of the two ball screw shafts is rotationally driven by a different injection motor. Although not shown, an injection motor and a ball screw shaft rotation transmitting means may be arranged so that two ball screw shafts are rotationally driven by one injection motor, or two ball screw shafts are provided. The injection motor and the rotation transmitting means 1 may be arranged so that the above-described injection motors are driven to rotate in cooperation with each other. As described above, the rotational driving form of the ball screw shaft in the fixed plate may be appropriately adjusted according to the injection capacity required of the two-plate injection device and the size of the two-plate injection device. good.

    2 fixing plate, 3 moving plate, 3a ball screw nut storage through hole, 3b ball screw nut storage through hole, 4 screw, 4a screw rotation support section, 4b screw shaft rotation transmission means, 10 2 plate type injection device, 11 cylinder barrel , 20 ball screw mechanism, 20a ball screw shaft, 20b ball screw nut, 21 ball screw mechanism, 21a ball screw shaft, 21b ball screw nut, 24 ball screw shaft rotation support part, 31 injection motor, 31a ball screw shaft rotation transmission means , 32 injection motor, 32a ball screw shaft rotation transmission means, 41 metering motor, 50 ring type load cell, 51 ring type load cell

Claims (2)

A fixed plate, a cylinder barrel disposed in front of the fixed plate, a moving plate provided at the rear of the fixed plate so as to be able to advance and retreat with respect to the fixed plate, and the moving plate with respect to the fixed plate. A pair of ball screw mechanisms for advancing and retreating, an injection motor for driving the pair of ball screw mechanisms, a screw supported on the moving plate so as to be rotatable around an axis, and a metering motor for rotating the screw. A two-plate injection device, wherein the screw is capable of moving back and forth in the cylinder barrel by moving the moving plate forward and backward with respect to the fixed plate,
Ball screw shafts of the pair of ball screw mechanisms are rotatably supported by the fixed plate, respectively.
Ball screw nuts combined with the ball screw shaft are respectively housed in ball screw nut housing through holes that penetrate the moving plate back and forth,
At least one of the ball screw nuts is supported by the moving plate via a ring type load cell fixed to the rear of the moving plate in a state housed in the ball screw nut housing through hole. Two-plate injection device. A ball screw shaft rotation transmitting unit disposed between the ball screw shaft end portion penetrating the cylinder barrel side of the fixed plate, and an output shaft of at least one injection motor disposed on the fixed plate; The two-plate injection device according to claim 1, wherein the ball screw shaft is rotated.

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