JP2018069286A - Injection device and molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection device which can drive a plunger suitably by a motor.SOLUTION: An integrated transmission mechanism 31 of an injection device 9 includes: a joint piston 41 which is positioned on a rear side of a plunger 23 and moves together with the plunger 23 when drive force of an injection motor 27 is transmitted without a fluid pressure apparatus; a cylinder member 39 which houses the joint piston 41 slidably and has a head side chamber 39h filled with a liquid on a rear side of the joint piston 41; a pressurizing member 47 which is driven by a motor for boost 29 without the fluid pressure apparatus and pressurizes the liquid in the head side chamber 39h; an auxiliary piston 46 which is positioned on a rear side of the joint piston 41 and is fixed to the joint piston 41; and an auxiliary cylinder chamber 48 which houses the auxiliary piston 46 slidably and has a front side chamber 48a filled with a liquid on a front side of the auxiliary piston 46.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an injection apparatus that injects a molding material in a liquid or solid-liquid coexistence state into a mold, and a molding machine including the injection apparatus. The molding machine is, for example, a die casting machine or a plastic injection molding machine.

  In recent years, it has been proposed to make the injection device of a die casting machine all electric (for example, Patent Documents 1 to 4). That is, a technique has been proposed in which a plunger that pushes a molding material into a cavity of a mold is moved by a driving force of an electric motor without using a driving force of a pump or an accumulator.

Japanese Patent Laying-Open No. 2015-199087 Japanese Patent Laying-Open No. 2015-199088 JP 2009-183966 A JP, 2014-210282, A

  It is preferable that various proposals have been made on the specific structure for driving the plunger by the driving force of the electric motor to enrich the technology.

  An injection device according to an aspect of the present invention includes a first electric motor, a second electric motor, and a transmission mechanism interposed between the electric motor and the injection plunger. The transmission mechanism includes the injection plunger. A coupling piston that moves with the injection plunger by transmitting the driving force of the first electric motor without passing through a fluid pressure device, and slidably accommodates the coupling piston. A cylinder member having a head side chamber filled with liquid on the rear side of the joint piston, and pressurization for pressurizing the liquid in the head side chamber driven by the second electric motor without passing through a fluid pressure device. A member, an auxiliary piston fixed to the joint piston, and slidably receiving the auxiliary piston, and on the front side of the auxiliary piston. And a, an auxiliary cylinder chamber having a side chamber before the liquid is filled.

  Preferably, the transmission mechanism further includes a flow path communicating the head side chamber and the front chamber.

  Preferably, the transmission mechanism includes an accumulator that communicates with the front chamber.

  Preferably, the transmission mechanism has a flow rate control valve capable of controlling the flow rate of the liquid discharged from the front chamber.

  Preferably, the pressurizing member is located behind the joint piston across the head side chamber, and at least a part of the auxiliary cylinder chamber is located in the pressurizing member.

  Preferably, the second electric motor is a rotary type, and the transmission mechanism is screwed to the screw shaft, which is coaxially fixed to the pressure member, and the second motor. A nut to which rotation of the electric motor is transmitted, the auxiliary cylinder chamber extends in the pressure member and the screw shaft, and the movable range of the auxiliary piston is It extends over the pressure member and the screw shaft.

  Preferably, the first motor and the second motor are rotary, and the transmission mechanism converts the rotation of the first motor into a translational motion and transmits the translation to the injection plunger, and A second screw mechanism having a small diameter and a small lead as compared with the first screw mechanism, which converts the rotation of the second electric motor into a translational motion and transmits it to the pressurizing member.

  Preferably, in the cylinder member, the front side of the joint piston is not filled with liquid.

  The molding machine which concerns on one embodiment of this invention has said injection apparatus, the mold clamping apparatus which clamps a metal mold | die, and the extrusion apparatus which extrudes a molded article from the said metal mold | die.

  According to the present invention, the plunger can be suitably driven by the electric motor.

The schematic diagram which shows the principal part structure of the die-casting machine which has the injection apparatus which concerns on 1st Embodiment of this invention. The typical sectional view showing the important section composition of the injection device of Drawing 1. 3A and 3B are enlarged views of a rear portion of the cylinder mechanism in the injection apparatus of FIG. The timing chart for demonstrating operation | movement of the injection apparatus of FIG. The schematic diagram which shows the principal part structure of the injection device which concerns on 2nd Embodiment of this invention. The timing chart for demonstrating operation | movement of the injection apparatus of FIG.

<First Embodiment>
(Overall configuration of die casting machine)
FIG. 1 is a side view partially including a sectional view showing a configuration of a main part of a die casting machine 1 according to a first embodiment of the present invention.

  The die casting machine 1 injects a molten metal material (molten metal) into a mold 101 (a space such as a cavity Ca, etc .; the same applies hereinafter), and solidifies the molten metal in the mold 101. Product (molded product). The metal is, for example, aluminum or an aluminum alloy. It is also possible to use a solid-liquid coexisting metal instead of the molten metal.

  The mold 101 includes, for example, a fixed mold 103 and a moving mold 105. In the description of the present embodiment, for convenience, the cross section of the fixed mold 103 or the movable mold 105 is shown by one type of hatching, but these molds may be of a direct engraving type or a nested type. It may be a thing. Further, the fixed mold 103 and the moving mold 105 may be combined with a core or the like.

  The die casting machine 1 includes, for example, a machine main body 3 that performs a mechanical operation for molding, and a control unit 5 that controls the operation of the machine main body 3.

  The machine body 3 includes, for example, a mold clamping device 7 that opens and closes and molds the mold 101, an injection device 9 that injects molten metal into the mold 101, and a die-cast product that is a fixed mold 103 or a movable mold 105. And an extrusion device 11 for extruding from the moving mold 105 in FIG. In the machine main body 3, the configuration other than the injection device 9 (for example, the configuration of the mold clamping device 7 and the extrusion device 11) is basically (excluding the portion related to the mounting of the injection device 9, for example) and various known types. The configuration may be the same.

  In the molding cycle, the mold clamping device 7 moves the moving mold 105 toward the fixed mold 103 and closes the mold. Further, the mold clamping device 7 performs mold clamping by applying a mold clamping force corresponding to the extension amount of the tie bar (reference number omitted) to the mold 101. A cavity Ca having the same shape as the molded product is formed in the clamped mold 101. The injection device 9 injects and fills molten metal into the cavity Ca. The molten metal filled in the cavity Ca is deprived of heat by the mold 101 and cooled and solidifies. Thereby, a molded article is formed. Thereafter, the mold clamping device 7 opens the mold by moving the moving mold 105 away from the fixed mold 103. At this time or thereafter, the extrusion device 11 extrudes the molded product from the moving mold 105.

  The control unit 5 includes, for example, a control device 13 (see FIG. 2) that performs various calculations and outputs a control command, a display device 15 that displays an image, and an input device 17 that receives an operator's input operation. ing. From another viewpoint, the control unit 5 includes, for example, a control panel (not shown) having a power supply circuit, a control circuit, and the like, and an operation unit 19 as a user interface.

  The control device 13 (see FIG. 2) is provided, for example, on a control panel (not shown) and the operation unit 19. The control device 13 may be divided or distributed as appropriate. For example, the control device 13 includes a lower control device for each of the mold clamping device 7, the injection device 9, and the extrusion device 11, and a higher control device that performs control such as synchronization between the lower control devices. May be configured.

  The display device 15 and the input device 17 are provided in the operation unit 19, for example. For example, the operation unit 19 is provided in a fixed portion of the mold clamping device 7. The display device 15 is configured by a touch panel including a liquid crystal display or an organic EL display, for example. The input device 17 is configured by, for example, a mechanical switch and the touch panel.

  In the case where attention is paid to the injection device 9 in the die casting machine 1, the control unit 5 may be regarded as a control unit of the injection device 9.

(Configuration of injection device)
The injection device 9 includes, for example, a sleeve 21 that communicates with the mold 101, a plunger 23 that can slide within the sleeve 21, and an injection drive unit 25 that drives the plunger 23. In the description of the injection device 9, the mold 101 side (the left side in FIG. 1) may be referred to as the front, and the opposite side may be referred to as the rear.

  The sleeve 21 is, for example, a cylindrical member connected to the fixed mold 103, and a supply port 21 a for receiving the molten metal into the sleeve 21 is opened on the upper surface. The plunger 23 has a plunger tip 23a that can slide in the front-rear direction within the sleeve 21, and a plunger rod 23b having a tip fixed to the plunger tip 23a.

  When the mold clamping of the mold 101 by the mold clamping device 7 is completed, one shot of molten metal is poured into the sleeve 21 from the supply port 21a by a hot water supply device (not shown). Then, when the plunger 23 slides forward in the sleeve 21 from the illustrated position, the molten metal in the sleeve 21 is pushed out (injected) into the mold 101.

(Schematic configuration of injection drive)
FIG. 2 is a schematic diagram showing a specific configuration of the injection device 9 (injection driving unit 25). Although FIG. 2 is basically a side view, for the sake of illustration, a part (for example, a hydraulic system) is not limited to this. FIG. 2 also includes a cross-sectional view as appropriate.

  The injection device 9 is configured as a so-called all-electric injection device. That is, the injection device 9 has an injection motor 27 and a pressure-increasing motor 29, and the plunger 23 is basically driven by the driving force of the injection motor 27 and the pressure-increasing motor 29 throughout the entire injection process. Driven and not driven by the driving force of hydraulic equipment such as pumps and accumulators.

  The injection motor 27 is mainly used for low-speed injection and high-speed injection (in a narrow sense), and the pressure-increasing motor 29 is mainly used for pressure increase. The injection device 9 is interposed between the plunger 23 and these motors in order to transmit the driving force of the injection motor 27 and the pressure-increasing motor 29 to the plunger 23 and to switch the motor to be used according to the progress of the process. An integrated transmission mechanism 31 is provided.

  The integrated transmission mechanism 31 is connected to the plunger 23, transmits the driving force of the injection motor 27 and the pressure-increasing motor 29 to the plunger 23, and contributes to the switching of the motor to be used, and the injection motor 27. An injection transmission mechanism 35 for transmitting the driving force to the cylinder mechanism 33 and a pressure increasing transmission mechanism 37 for transmitting the driving force of the pressure-increasing electric motor 29 to the cylinder mechanism 33 are provided.

(Electric motor)
The number of electric motors may be set as appropriate. In the description of the present embodiment, an example in which two injection motors 27 and one pressure-increasing motor 29 are provided is taken as an example.

  The injection motor 27 and the pressure-increasing motor 29 are constituted by, for example, a rotary motor, and although not particularly illustrated, the stator constituting one of the field and the armature and the other of the field and the armature are constituted. And a rotor that rotates relative to the stator. These motors may be of an appropriate type, and may be, for example, a DC motor, an AC motor, a synchronous motor, or an induction motor. May be.

  The injection motor 27 and the pressure-increasing motor 29 are configured as servo motors, for example. That is, the injection motor 27 has a rotation sensor 27s that detects the rotation thereof, and the rotation speed is feedback-controlled by a servo driver (not shown) based on the detection value of the rotation sensor 27s. Similarly, the pressure-increasing electric motor 29 has a rotation sensor 29s that detects the rotation thereof, and the rotation speed is feedback-controlled by a servo driver (not shown) based on the detection value of the rotation sensor 29s. The rotation sensors of the injection motor 27 and the pressure-increasing motor 29 are, for example, encoders that output a number of pulses corresponding to the rotation amount.

  Further, the servo driver of the booster motor 29 can detect, for example, a current flowing through the booster motor 29 and perform torque feedback control based on the detected value. The servo driver of the injection motor 27 may also be capable of such torque feedback control.

  It is preferable that the injection motor 27 and the pressure-increasing motor 29 (particularly the injection motor 27) are constituted by low inertia motors. That is, these electric motors are preferably constituted by electric motors whose rotor inertia is relatively small with respect to the rated torque. The low inertia motor is often described as being a low inertia motor in its catalog or specification, and it can be specified based on the description whether the motor is a low inertia motor. Generally, a low inertia motor is configured with a rotor diameter that is relatively small with respect to the axial length of the rotor. However, it is also known that low inertia is realized by optimizing the magnet material, rotor diameter, iron core shape, stacking thickness, and the like.

  The arrangement of the injection motor 27 and the pressure-increasing motor 29 may be set as appropriate. For example, the injection motor 27 and the pressure-increasing motor 29 are arranged in parallel with the cylinder mechanism 33. More specifically, for example, the injection motor 27 has its output shaft 27a facing forward. The pressure-increasing electric motor 29 has its output shaft 29a directed rearward.

  Further, for example, the absolute position around the axis of the cylinder mechanism 33 of the injection motor 27 and the pressure-increasing motor 29 and the relative position between the two motors may be set as appropriate. For example, the two injection motors 27 are arranged substantially symmetrically with respect to the cylinder mechanism 33 in a plan view or a side view. The pressure-increasing motor 29 may be disposed between the two injection motors 27 around the axis of the cylinder mechanism 33, or may be disposed coaxially with the one injection motor 27.

(Basic configuration of cylinder mechanism)
As a basic configuration, the cylinder mechanism 33 has a configuration similar to a hydraulic device including a hydraulic cylinder (injection cylinder). Specifically, for example, the cylinder mechanism 33 is fixed to the cylinder member 39, the joint piston 41 slidably accommodated in the cylinder member 39, and the joint piston 41. A front rod 43 extending toward one side (forward) of the moving direction of the piston 41 for use and a pressurizing member 47 positioned behind the joint piston 41 are provided.

  The cylinder mechanism 33 is disposed coaxially with the plunger 23. The front rod 43 is coaxially connected to the rear end of the plunger 23 via a coupling 49. The cylinder member 39 is provided fixed (impossible to move). Therefore, the plunger 23 can be driven by transmitting the driving force of the injection motor 27 to the front rod 43. Further, by transmitting the driving force of the pressure-increasing electric motor 29 to the pressurizing member 47, the liquid (for example, oil) behind the joint piston 41 can be pressurized and the plunger 23 can be driven.

  The joint piston 41 has, for example, a substantially cylindrical shape. The front rod 43 is generally circular in cross section and extends with a substantially constant cross sectional shape. The inside of the cylinder member 39 is partitioned by a coupling piston 41 into a rod side chamber 39r on the side from which the front rod 43 extends and a head side chamber 39h on the opposite side. For example, the cylinder member 39 is fixed to a frame 51 fixed to a fixed die plate (reference numeral omitted) of the mold clamping device 7 that holds the fixed mold 103.

  The head side chamber 39h is filled with liquid as in a general hydraulic cylinder. On the other hand, unlike the general hydraulic cylinder, the rod side chamber 39r is not filled with liquid, and is open to the atmosphere, for example. Accordingly, the rod side chamber 39r can be arranged with at least a part of a configuration (injection transmission mechanism 35) for transmitting the driving force of the injection motor 27 to the front rod 43. Note that a small amount of liquid (oil) that contributes to lubrication between the joint piston 41 and the cylinder member 39 may be stored in the rod side chamber 39r.

  3A and 3B are enlarged views of a rear portion of the cylinder mechanism 33. FIG. FIG. 3A shows a state where the joint piston 41 is positioned at the retreat limit, and FIG. 3B shows a state where the joint piston 41 is slightly advanced from the retreat limit.

  The pressurizing member 47 is constituted by, for example, a piston that can slide the cylinder member 39. The pressurizing member 47 has an inside of the cylinder member 39, the head side chamber 39h, and a space on the opposite side (rear side) (reference number omitted. It is divided into). For example, the rear space is not filled with liquid and is open to the atmosphere.

  More specifically, the pressure member 47 has a main body portion 47a that slides in the cylinder member 39, and a protruding portion 47b that protrudes forward from the main body portion 47a. The protrusion 47 b has a smaller diameter than the main body 47 a (the inner surface of the cylinder member 39) and does not slide in the cylinder member 39. The protrusion 47b is in contact with the rear end surface of the joint piston 41, and can restrict the proximity of the joint piston 41 and the main body 47a beyond a certain level. Thereby, for example, the volume between the two (head side chamber 39h) is ensured, and the retreat limit of the joint piston 41 is regulated by the pressure member 47 located at the retreat limit.

  The shapes of the main body 47a and the protrusion 47b may be appropriate. The shape of the main body 47a is, for example, a substantially cylindrical shape if the presence of an O-ring (not shown) is ignored. The projecting portion 47b has, for example, a columnar base portion 47ba having a diameter smaller than that of the main body portion 47a, and an end surface of the base portion 47ba as a lower base in order from the main body portion 47a (the diameter is reduced from the end surface of the base portion 47ba). A frustoconical intermediate portion 47bb, and a columnar tip portion 47bc whose end face is the upper base of the intermediate portion 47bb. In addition, the protrusion part 47b may be comprised only from the columnar part or the truncated cone part.

  The retreat limit of the pressure member 47 may be defined, for example, by contacting the inner side (stopper) of the rear end surface of the cylinder member 39. The backward limit of the joint piston 41 may be defined, for example, by contact with the protruding portion 47b as described above, or a stopper (not shown) provided in the cylinder member 39 contacts the joint piston 41. May be defined. The advance limit of the joint piston 41 may be defined by, for example, a stopper (not shown) provided in the cylinder member 39 coming into contact with the joint piston.

  In the example shown in the figure, the diameter of the joint piston 41 and the diameter of the pressure member 47 (main body 47a) are the same, but they may be different from each other. That is, the cylinder member 39 may have a different diameter between a portion where the joint piston 41 slides and a portion where the pressure member 47 slides. From the viewpoint of reducing the burden on the pressure-increasing electric motor 29, the diameter of the pressure member 47 is preferably smaller than the diameter of the joint piston 41.

(Auxiliary part of cylinder mechanism)
As shown in FIGS. 3A and 3B, the cylinder mechanism 33 has a configuration that the general hydraulic cylinder does not have, and an auxiliary rod 45 that extends rearward from the joint piston 41. And an auxiliary piston 46 fixed to the auxiliary rod 45, and an auxiliary cylinder chamber 48 in which the auxiliary piston 46 is slidably accommodated. These contribute to, for example, reduction of surge pressure and / or reduction of excess or deficiency of liquid.

  The auxiliary rod 45 is, for example, a rod extending with a constant cross-sectional shape, and the cross-sectional shape is, for example, a substantially circular shape. The diameter of the auxiliary rod 45 may be appropriately set as long as it is smaller than the inner diameter of the cylinder member 39 (head side chamber 39h). For example, it may be larger than or equal to the diameter of the front rod 43, It may be small (example shown in the figure), and is preferably smaller than the diameter of the front rod 43 from the viewpoint of downsizing the apparatus or reducing the inertial force applied to the plunger 23.

  The auxiliary piston 46 has, for example, a substantially cylindrical shape, and is fixed to the rear end of the auxiliary piston 46. The diameter of the auxiliary piston 46 may be appropriately set as long as it is larger than the diameter of the auxiliary rod 45. For example, it may be larger than, equal to, or smaller than the diameter of the front rod 43. (Example of illustration) From the viewpoint of downsizing the apparatus or reducing the inertial force applied to the plunger 23, it is preferable that the diameter is equal to or less than the diameter of the front rod 43.

  The auxiliary cylinder chamber 48 is provided, for example, inside the pressure member 47 and a screw shaft 87 described later. More specifically, for example, the auxiliary cylinder chamber 48 extends from the protruding portion 47 b (more specifically, for example, the base portion 47 ba) of the pressure member 47 to the rear end of the screw shaft 87. The auxiliary cylinder chamber 48 has, for example, a constant cross-sectional area from the front end to the rear end.

  The auxiliary cylinder chamber 48 is partitioned by an auxiliary piston 46 into a front front chamber 48a and a rear rear chamber 48b (having a volume of 0 in FIG. 3A). The front chamber 48a is filled with liquid. For example, the rear chamber 48b is open to the atmosphere and is not filled with liquid.

  The front chamber 48 a communicates with the outside via an auxiliary flow path 50 provided in the pressure member 47 and the screw shaft 87. For example, one end of the auxiliary flow path 50 opens to the front chamber 48 a ahead of the advance limit of the auxiliary piston 46, and the other end opens to the outside at the rear end face of the screw shaft 87.

  The stroke of the auxiliary piston 46 (equivalent to the stroke of the joint piston 41) extends over both the pressure member 47 and the screw shaft 87, for example. That is, at least a part of the auxiliary piston 46 is located in the pressure member 47 in the forward limit, and at least a part thereof is located in the screw shaft 87 in the backward limit. In the illustrated example, the front end of the auxiliary piston 46 is positioned at the protruding portion 47b (more specifically, the root portion 47ba) at the forward limit, and the rear end thereof is at the rear end of the screw shaft 87 at the backward limit. To position.

  Since the auxiliary piston 46 is fixed to the joint piston 41, for example, the forward limit of the auxiliary piston 46 with respect to the auxiliary cylinder chamber 48 is a stopper (not shown) in the cylinder member 39. It is prescribed | regulated by contacting. The retreat limit of the auxiliary piston 46 with respect to the auxiliary cylinder chamber 48 is defined by the joint piston 41 coming into contact with the pressurizing member 47. However, the advancing limit and / or the retreating limit of the auxiliary piston 46 may be defined by contacting a stopper (not shown) provided in the auxiliary cylinder chamber 48.

(Hydraulic system related to cylinder mechanism)
Returning to FIG. 2, the integrated transmission mechanism 31 has a liquid control unit 53 for controlling the flow of the liquid related to the cylinder mechanism 33. The liquid control unit 53 includes, for example, a communication channel 55 that connects the head side chamber 39h and the front chamber 48a, an accumulator 57 that is connected to the head side chamber 39h and / or the front chamber 48a (both in the present embodiment), and a communication flow A head side valve 59 and an auxiliary valve 61 provided in the passage 55 are provided.

  The communication channel 55 (and other channels) is constituted by, for example, a steel pipe, a flexible hose, or a metal block. Note that at least a part of the communication channel 55 is a flexible tube formed of a flexible hose or the like corresponding to the fact that the cylinder member 39 and the pressurizing member 47 (front chamber 48a) are relatively movable. It is a road.

  One end of the communication channel 55 communicates with the head side chamber 39 h behind the retreat limit of the joint piston 41, and the other end of the communication channel 55 is an end that opens on the rear end surface of the screw shaft 87 of the auxiliary channel 50. Communicates. By providing the communication flow path 55, when the joint piston 41 and the auxiliary piston 46 fixed to each other advance, the liquid discharged from the front chamber 48a as the volume of the front chamber 48a decreases. The liquid can be supplied to the head side chamber 39h whose volume is increased. Similarly, when the joint piston 41 and the auxiliary piston 46 move backward, the liquid can be supplied to the front side chamber 48a by the liquid discharged from the head side chamber 39h.

  The amount of change in the volume of the head side chamber 39h accompanying the movement of the joint piston 41 is a magnitude obtained by multiplying the cross sectional area of the joint piston 41 by the cross section of the auxiliary rod 45 and the amount of movement of the joint piston 41. That's it. The amount of change in the volume of the front chamber 48a accompanying the movement of the auxiliary piston 46 is a magnitude obtained by multiplying the cross-sectional area of the auxiliary piston 46 by the cross-sectional area of the auxiliary piston 46 and the amount of movement of the auxiliary piston 46. That's it. Therefore, the excess or deficiency of the liquid when the liquid is replenished between the head side chamber 39h and the front side chamber 48a is determined by ignoring the influence of the operation of the pressurizing member 47. The closer to 41 the cross-sectional area, the lower the value. In this respect, the diameter of the auxiliary piston 46 is preferably relatively large. For example, unlike the illustrated example, the diameter may be larger than the diameter of the front rod 43.

  The accumulator 57 may be configured by an accumulator of an appropriate type such as a weight type, a spring type, a gas pressure type (including a pneumatic type), a cylinder type, and a prada type. In the illustrated example, the accumulator 57 is a cylinder type, and has a cylinder member and a piston slidably accommodated in the cylinder member, although the reference numerals are omitted. The inside of the cylinder member is partitioned into a gas chamber and a liquid chamber by a piston, and the liquid chamber is connected to the cylinder mechanism 33.

  Unlike the accumulator connected to a normal injection cylinder, the accumulator 57 is not intended to drive the joint piston 41 by liquid delivery, and the pressure thereof may be relatively low. For example, the pressure of the gas chamber of the accumulator 57 (for example, the maximum pressure set in the specification of the accumulator 57 or the maximum pressure actually generated during the molding cycle) is a pressure (1 MPa) defined as high pressure in the high-pressure gas safety method. May be lower. A so-called mini bottle may be used as the accumulator 57.

  The accumulator 57 is connected to, for example, the communication channel 55 and eventually communicates with the head side chamber 39h and the front side chamber 48a. However, as will be understood from the operation described later, the accumulator 57 does not necessarily need to communicate with the front chamber 48a, and may be connected to the front chamber 48a separately from the communication channel 55.

  The head side valve 59 is provided in the communication flow path 55 and can allow a bidirectional flow between the head side chamber 39h and the front side chamber 48a, and at least a flow from the head side chamber 39h to the front side chamber 48a ( From another viewpoint, the discharge of the liquid from the head side chamber 39h can be prohibited. By closing the head side valve 59 and prohibiting the discharge of liquid from the head side chamber 39h, for example, when the driving force of the pressure-increasing electric motor 29 is transmitted to the pressure member 47 and the pressure member 47 is advanced, The pressure in the head side chamber 39h can be increased, and a force in the forward direction can be applied to the joint piston 41. That is, the driving force of the pressure-increasing electric motor 29 can be transmitted to the plunger 23. For example, the head side valve 59 is provided in the communication channel 55 on the head side chamber 39 h side from the connection position between the communication channel 55 and the accumulator 57.

  The head side valve 59 may have an appropriate configuration as long as it can perform the above functions. For example, the head side valve 59 is configured by a 2-port 2-position non-leak switching valve that is closed by a spring force and opened by an electromagnetic force. ing. A non-leak valve is a valve with little or no liquid leak, and is often described as a non-leak valve in its catalog or specifications, and whether or not it is a non-leak valve based on the description. Can be specified. As a non-leak valve, for example, a valve that has no leakage at all by adopting a poppet structure or the like is known.

  The auxiliary valve 61 is for controlling the flow rate of the liquid discharged from the front chamber 48a. By controlling the flow rate of the liquid from the front chamber 48a, for example, the speed of the auxiliary piston 46 and the like can be controlled, and thus the inertia force in the forward direction at the time of injection can be controlled. For example, the auxiliary valve 61 is provided in the communication channel 55 closer to the front chamber 48 a than the connection position between the communication channel 55 and the accumulator 57.

  The auxiliary valve 61 may be appropriate as long as the flow rate can be controlled. For example, the auxiliary valve 61 is configured by a non-leak switching valve with a flow rate control function that is closed by a spring force and opened by an electromagnetic force. The non-leak valve is as described above. However, there is little or no leakage only when fully closed. As a thing with a flow control function, what combined a poppet structure and a spool structure (valve unit which combined a switching valve and a flow control valve from another viewpoint) is known, for example. The flow rate control may or may not perform pressure compensation and / or temperature compensation. The auxiliary valve 61 may be a servo valve that performs feedback control regarding flow rate control, or may be a proportional valve that performs open control.

(Transmission mechanism for injection)
The injection transmission mechanism 35 includes, for example, a winding transmission mechanism (reference numeral omitted) and an injection screw mechanism 69. Specifically, for example, the injection transmission mechanism 35 includes a pulley 65 fixed to the output shaft 27a of the injection motor 27, a belt 67 hung on the pulley 65, a nut 71 on which the belt 67 is hung, And a screw shaft 73 screwed into the nut 71. The pulley 65, the belt 67, and the nut 71 constitute a pulley / belt mechanism that is a kind of a winding transmission mechanism. The nut 71 and the screw shaft 73 constitute an injection screw mechanism 69.

  The pulley 65 and the belt 67 transmit the rotation of the injection motor 27 to the nut 71. These members contribute to, for example, arranging the injection motor 27 in parallel with the screw shaft 73 and improving the degree of freedom of arrangement of the injection motor 27 with respect to the injection screw mechanism 69. . The diameter of the pulley 65 and the diameter of the nut 71 may be the same, or one may be larger than the other. That is, the winding transmission mechanism of the injection transmission mechanism 35 may or may not contribute to deceleration or acceleration. In the illustrated example, the diameter of the nut 71 is smaller than the diameter of the pulley 65. Accordingly, the rotation of the injection motor 27 is increased and transmitted to the nut 71. The belt 67 may be, for example, a toothed belt or may have no teeth. The winding transmission mechanism of the injection transmission mechanism 35 may be of a type other than the pulley / belt mechanism, such as a sprocket / chain mechanism.

  The screw mechanism 69 for injection contributes to converting the rotation of the electric motor 27 for injection into translational motion. The injection screw mechanism 69 may be a ball screw mechanism in which a ball is interposed between the nut 71 and the screw shaft 73, or may be a sliding screw mechanism in which no ball is interposed. The former is preferable from the viewpoint of improving the transmission efficiency and increasing the speed. The screw mechanism 69 for injection may be of a single thread type with one thread groove, or may be of a multiple thread type with two or more thread grooves.

  The screw shaft 73 is provided on the front rod 43, for example. That is, a thread groove is formed in a part (illustrated example) or all of the outer peripheral surface of the front rod 43, and a part (illustrated example) or all of the front rod 43 is a screw shaft 73. It should be noted that the outer diameter of the screw may be larger than, equal to, or smaller than the diameter of the portion of the front rod 43 where the thread groove is not formed. The ratio and position of the screw shaft 73 in the front rod 43 may be set as appropriate. For example, the rear end of the screw shaft 73 is positioned immediately before the joint piston 41, and the front end of the screw shaft 73 is used for the joint. The piston 41 is positioned forward (preferably near the front end) of the cylinder member 39 in a state where the piston 41 is in the retreat limit, and the screw shaft 73 extends over half of the length of the front rod 43.

  The nut 71 is accommodated in the cylinder member 39 (rod side chamber 39r), for example. The diameter of the outer peripheral surface of the nut 71 is, for example, smaller than the diameter of the inner surface on which the joint piston 41 of the cylinder member 39 slides. However, at the position where the nut 71 is arranged, the diameter of the nut 71 can be increased by forming a recess in the inner surface of the cylinder member 39 (thinning it) or increasing the diameters of both the inner surface and the outer surface of the cylinder member 39. It is good also as more than the diameter of the inner surface where the piston 41 for couplings of the cylinder member 39 slides. The position of the nut 71 in the axial direction of the cylinder member 39 may be an appropriate position, but is, for example, in front of the center of the cylinder member 39, preferably in the vicinity of the front end.

  The belt 67 hung on the nut 71 extends over the inside and outside of the cylinder member 39 through an opening (reference numeral omitted) formed on the side surface of the cylinder member 39. The diameter of the outer peripheral surface of the portion of the belt 67 wound around the nut 71 is made smaller than the diameter of the inner surface on which the joint piston 41 of the cylinder member 39 slides, similarly to the diameter of the outer peripheral surface of the nut 71 described above. Alternatively, at the position where the nut 71 is disposed, the coupling piston 41 of the cylinder member 39 is slid by forming a recess in the inner surface of the cylinder member 39 (example shown in the figure) or increasing the diameter of the cylinder member 39. It may be greater than the diameter of the moving inner surface.

  The nut 71 is allowed to rotate around the axis and is restricted from moving in the axial direction. On the other hand, the screw shaft 73 is restricted from rotating around the axis and is allowed to move in the axial direction. Therefore, when the rotation of the injection motor 27 is transmitted to the nut 71 via the pulley 65 and the belt 67, the screw shaft 73 moves in the axial direction. As a result, the plunger 23 connected to the front rod 43 moves in the front-rear direction.

  For example, the nut 71 is allowed to rotate about the axis and the axial movement is restricted by the nut 71 being supported by the cylinder member 39 via an appropriate bearing. For example, the rotation of the screw shaft 73 around the shaft is regulated by, for example, providing the screw shaft 73 eccentrically with respect to the joint piston 41, or fixing a spline groove (not shown) provided on the screw shaft 73 to the cylinder member 39. It is done by being guided by various guides.

  Two belts 67 are hung on the nut 71, and the driving force of the two injection motors 27 is transmitted. However, a nut 71 may be provided for each injection motor 27. In the control of the two injection motors 27, tandem control may be performed. Further, only one injection motor 27 may be provided.

(Transmission mechanism for pressure increase)
The pressure increasing transmission mechanism 37 includes, for example, a winding transmission mechanism (reference numeral omitted) and a pressure increasing screw mechanism 83. Specifically, the pressure-increasing transmission mechanism 37 includes a pulley 79 fixed to the output shaft 29a of the pressure-increasing electric motor 29, a belt 81 hung on the pulley 79, a nut 85 on which the belt 81 is hung, and a nut 85 And a screw shaft 87 fixed to the pressure member 47. The pulley 79, the belt 81, and the nut 85 constitute a pulley / belt mechanism that is a kind of a winding transmission mechanism. The nut 85 and the screw shaft 87 constitute a pressure increasing screw mechanism 83.

  The pulley 79 and the belt 81 transmit the rotation of the pressure-increasing motor 29 to the nut 85. These members contribute to, for example, arranging the pressure-increasing electric motor 29 in parallel with the screw shaft 87 and improving the degree of freedom of the arrangement of the pressure-increasing motor 29 with respect to the pressure-increasing screw mechanism 83. . The diameter of the pulley 79 and the diameter of the nut 85 may be the same, or one may be larger than the other. That is, the winding transmission mechanism of the pressure increase transmission mechanism 37 may or may not contribute to deceleration or speed increase. In the illustrated example, the diameter of the nut 85 is larger than the diameter of the pulley 79. Therefore, the nut 85 is driven with a torque larger than the torque generated by the pressure-increasing electric motor 29. The belt 81 may be, for example, a toothed belt or may have no teeth. The winding transmission mechanism of the pressure increase transmission mechanism 37 may be of a type other than the pulley / belt mechanism, such as a sprocket / chain mechanism.

  The pressure-increasing screw mechanism 83 contributes to converting the rotation of the pressure-increasing motor 29 into translational motion. The pressure-increasing screw mechanism 83 may be a ball screw mechanism in which a ball is interposed between the nut 85 and the screw shaft 87, or may be a sliding screw mechanism in which no ball is interposed. The former is preferable from the viewpoint of obtaining a desired boosting curve with high accuracy by improving the transmission efficiency, and the latter is preferable from the viewpoint of suppressing retraction of the pressurizing member 47 that receives pressure from the head side chamber 39h. The pressure-increasing screw mechanism 83 may be of a single thread type with one screw groove, or may be of a multiple thread type with two or more thread grooves.

  The nut 85 is allowed to rotate around the axis and is restricted from moving in the axial direction. On the other hand, the screw shaft 87 is restricted from rotating around the axis and is allowed to move in the axial direction. Therefore, when the rotation of the pressure-increasing electric motor 29 is transmitted to the nut 85 via the pulley 79 and the belt 81, the screw shaft 87 moves in the axial direction. As a result, the pressure member 47 fixed to the screw shaft 87 moves in the front-rear direction.

  For example, the nut 85 is allowed to rotate around the axis and the axial movement is restricted by supporting the nut 85 with an appropriate bearing. The rotation restriction of the screw shaft 87 is, for example, that the screw shaft 87 is eccentrically fixed with respect to the pressure member 47, or a spline groove (not shown) provided in the screw shaft 87 serves as a guide fixed to the cylinder member 39. The guide shaft (not shown) that is guided and / or parallel to the screw shaft 87 and only allowed to move in the axial direction is fixed to the screw shaft 87.

  The screw shaft 87 may be a member separate from the pressing member 47 and may be fixed to each other, or may be formed integrally with the pressing member 47 and fixed to the screw shaft 87.

  When comparing the injection screw mechanism 69 and the pressure increasing screw mechanism 83, for example, the pressure increasing screw mechanism 83 has a smaller lead and a diameter (for example, an effective diameter or a male thread valley diameter) compared to the injection screw mechanism 69. Is big. Further, for example, the injection screw mechanism 69 may be a ball screw mechanism, whereas the pressure increasing screw mechanism 83 may be a sliding screw mechanism.

  As can be understood from the above description, the driving force of the injection motor 27 is transmitted to the plunger 23 by a mechanical transmission mechanism, and is transmitted without passing through a fluid pressure device (for example, a hydraulic device). Yes. For example, the electric motor 27 for injection does not drive the plunger 23 by applying pressure to the working fluid or sending the working fluid like the electric motor that drives the pump. Similarly, the driving force of the pressure-increasing electric motor 29 is transmitted to the pressurizing member 47 by a mechanical transmission mechanism, and is transmitted without passing through a fluid pressure device (for example, a hydraulic device). For example, the pressure-increasing electric motor 29 does not drive the pressurizing member 47 by applying pressure to the working fluid or sending out the working fluid, like the electric motor that drives the pump.

(cover)
The injection device 9 has a cover 75 for mainly protecting the injection screw mechanism 69. The cover 75 is a substantially cylindrical member, for example, and is fixedly provided. For example, the cover 75 is fixed to the frame 51 so as to cover a hole through which the front rod 43 of the frame 51 is inserted. The inner diameter of the cover 75 (cylindrical portion) is larger than that of the coupling 49, for example. A hole through which the plunger rod 23 b is inserted is formed in the front end surface of the cover 75. The gap between the hole and the plunger rod 23b is preferably small or absent. The cover 75 extends in the axial direction of the plunger 23 from the front surface of the frame 51 to immediately after the plunger tip 23a positioned at the retreat limit.

  Accordingly, when the plunger 23 moves forward from the illustrated position (retreat limit), the plunger 23 extends from the cover 75. Further, the rear part (including the screw shaft 73) from the coupling 49 is blocked from the front by the cover 75 and the frame 51 until reaching the forward limit. As a result, for example, the screw shaft 73 is protected from molten metal splash.

(Control devices, sensors, etc.)
The control device 13 is configured by, for example, a computer including a CPU 89 and a memory 91, generates a control signal for controlling each unit based on an electrical signal input through the input unit 93, and generates the generated control signal. The control signal is output to each unit via the output unit 95.

  The electrical signal input to the control device 13 includes, for example, a detection signal from the position sensor 97 that detects the position of the plunger 23, a detection signal from the force sensor 99 that detects the force applied to the plunger 23, and the input device 17. It is the operation signal according to the user's operation. In addition, the detection signal of the rotation sensor 27 s of the injection motor 27, the detection signal of the rotation sensor 29 s of the pressure boosting motor 29, the detection signal of the current detector that detects the current flowing through the pressure boosting motor 29, and the opening degree of the auxiliary valve 61 May be input to the control device 13 in addition to or instead of the input to the servo driver that drives the electric motor or the control valve.

  The control signal output from the control device 13 is, for example, a control signal for controlling the injection motor 27, the pressure-increasing motor 29, the head side valve 59, the auxiliary valve 61, and the display device 15 (strictly, This is a control signal output to the driver.

  The position sensor 97 constitutes a magnetic or optical linear encoder together with a scale portion (not shown) fixed to the plunger 23, for example. In the illustrated example, the scale portion is provided on the front rod 43, and the position sensor 97 is located near the frame 51. The position sensor 97 and / or the control device 13 can specify the position and speed (injection speed) of the plunger 23 based on pulses generated by a number corresponding to the relative movement amount between the scale unit and the position sensor 97. It is.

  The force sensor 99 includes a load cell positioned between the plunger 23 and the front rod 43, for example. The load cell is, for example, a strain gauge type. Based on the detection signal from the force sensor 99, the control device 13 can specify the force applied to the plunger 23, and thus the pressure applied to the molten metal.

(Operation of injection device)
FIG. 4 is a timing chart for explaining the operation of the injection device 9.

In FIG. 4, the horizontal axis indicates time t. Line L _V represents the injection speed (the speed of the plunger 23), the line L _P indicates the injection pressure (pressure at which the plunger 23 is applied to the molten metal). The upper line indicates the rotation speed or servo-free state (servo-off state) of the injection motor 27 or the servo-lock state (servo-on state) of the pressure-increasing motor 29. , The servo-free state (servo OFF state), and the control state of the auxiliary valve 61 and the head side valve 59 are shown.

As can be understood from the injection speed (line L _V ) and the injection pressure (line L _P ), the injection device 9 generally has a low-speed injection (period T1), a high-speed injection (period T2), and pressure increase / hold. Pressure (period T3) is sequentially applied. That is, in the initial stage of injection, the injection device 9 advances the plunger 23 at a relatively low speed in order to prevent entrainment of the melt air, and then fills the melt without delaying the solidification of the melt. In view of the above, the plunger 23 is advanced at a relatively high speed. Thereafter, the injection device 9 increases the pressure of the molten metal in the cavity by the force in the direction in which the plunger 23 advances in order to eliminate sink marks in the molded product. Specifically, it is as follows.

(Before starting low-speed injection: ~ t0)
Immediately before the start of low-speed injection, the injection device 9 is in the state shown in FIG. That is, the joint piston 41 (plunger 23 and front rod 43) and the pressure member 47 are located at an initial position such as a retreat limit. The injection motor 27 and the pressure-increasing motor 29 are stopped. The head side valve 59 and the auxiliary valve 61 are closed, for example.

(Low speed injection (T1): t0 to t1)
When the clamping of the fixed mold 103 and the movable mold 105 is completed and a predetermined low-speed injection start condition is satisfied, for example, the molten metal is supplied to the sleeve 21, the control device 13 drives the injection motor 27. The driving force is transmitted to the front rod 43 via the injection transmission mechanism 35, and the plunger 23 advances. That is, low speed injection is performed by the driving force of the injection motor 27.

  At this time, the head side valve 59 and the auxiliary valve 61 are open (for example, fully open). That is, the head side chamber 39 h and the front side chamber 48 a are communicated with each other and connected to the accumulator 57. Then, the liquid discharged from the front chamber 48a as the joint piston 41 advances (advancement of the auxiliary piston 46 relative to the pressurizing member 47) returns to the head side chamber 39h. In the present embodiment, since the cross-sectional area of the auxiliary piston 46 is smaller than the cross-sectional area of the joint piston 41, a shortage of liquid occurs. This shortage is resolved by the accumulator 57.

  The pressure member 47 is stopped by the servo lock function or the brake of the pressure-increasing electric motor 29 and / or the pressure receiving area in the head side chamber 39h (the pressure of the liquid acts in the moving direction of the pressure member 47). Since the area) is larger than the pressure receiving area in the front chamber 48a, it is stopped at the retreat limit.

The speed of the plunger 23 is controlled by adjusting the rotational speed of the electric motor 27 for injection. Specifically, for example, the control device 13 feedback-controls the rotation speed of the injection motor 27 based on the speed of the plunger 23 detected by the position sensor 97. In FIG. 4, the rotation speed M _VL of the injection motor 27 at this time is made constant, thus, slower injection speed V _L is constant. However, multi-stage shifting may be performed.

  The speed feedback control here may control the speed based on the deviation of the speed itself, or may obtain the target position every moment in a predetermined time interval (for example, 1 ms) based on the target speed. Alternatively, the speed may be controlled based on the position deviation from moment to moment (substantially speed feedback is performed by position feedback). Since the speed is a derivative of the position, the latter may be regarded as feedback control based on the speed. The same applies to the high-speed injection described later.

The low-speed injection speed V _L may be appropriately set so as not to cause gas entrainment due to the molten metal, but is, for example, less than 1 m / s. Injection pressure in the low-speed injection is a relatively low P _L corresponding to injection speed is relatively slow.

(High-speed injection (T2): t1 to t3)
When the plunger 23 reaches a predetermined high speed switching position, the control device 13 increases the rotation speed of the injection motor 27 from M _VL to M _VH . As a result, the injection speed is increased from the relatively low _VL to the relatively high _VH , and high-speed injection is realized. Incidentally, with increasing injection speed, a P _H injection pressures slightly rises and. The high-speed injection speed V _H may be appropriately set in a range higher than the low-speed injection speed V _{L, and} is, for example, 1 m / s or more. Preferably it is 3 m / s or more.

  For example, the control device 13 converts the target speed set for each section in which the movement range of the plunger 23 into a plurality of sections into the target position of the plunger 23 from time to time, thereby performing position feedback control (substantial speed feedback control). (The gear is shifted based on the passage of time), and it is not detected whether or not the plunger 23 has reached the high-speed switching position. However, the control device 13 may switch the target speed by detecting that the plunger 23 has reached a predetermined high-speed switching position based on a signal from the position sensor 97.

Since high-speed injection is realized by controlling the rotation speed of the injection motor 27, the acceleration time (T4: t1 to t2) from the low-speed injection speed V _L to the high-speed injection speed V _H can be arbitrarily set. It is. In the case where the injection motor 27 is a low inertia motor, the acceleration time is controlled more accurately. For example, the speed increase from V _L = 0.20 m / s to V _H = 5.0 m / s can be performed in about 10 ms.

Further, the control device 13 starts driving the pressure-increasing electric motor 29 at an appropriate time before the pressure increase is started. In Figure 4, during acceleration the completion of the high-speed injection speed V _H (t2) driving the pressure-increasing motor 29 is started in and, exemplifies a case where the rotation speed is increased to a constant rotational speed M _VI Yes. The advance speed of the pressure member 47 during high-speed injection is lower than the advance speed (V _H ) of the joint piston 41, and affects the control of the high-speed injection speed V _H by controlling the number of revolutions of the injection motor 27. Has little or no effect. Then, by previously driving the pressure-increasing electric motor 29 in this way, the transition to pressure-increasing is performed smoothly.

(Deceleration by injection motor: t3 to t4)
When the predetermined deceleration start condition is satisfied (t3), the control device 13 decreases the rotational speed of the injection motor 27. Thereby, the plunger 23 is decelerated. Like deceleration, this deceleration is realized by controlling the rotation speed of the injection motor 27, so the deceleration time can be arbitrarily set. By configuring the injection motor 27 with a low-inertia motor, such a deceleration time is suitably set as in the case of the speed increase. Incidentally, even if the deceleration is started, the cavity Ca from the molten metal is generally filled, the pressure of the molten metal is kept in the vicinity of P _H or rises.

  The deceleration control of the injection motor 27 here may be open control or feedback control, similar to the speed control in the low speed injection and the high speed injection, and the speed feedback control may be the speed itself. It may be based on the deviation of, or may be based on the positional deviation every moment.

  The deceleration start condition may be appropriately set. For example, the deceleration is started when the plunger 23 reaches a predetermined deceleration start position. However, similarly to the high-speed switching position, the control device 13 may switch the target speed by detecting that the plunger 23 has reached the deceleration start position based on the signal from the position sensor 97, or may change the position every moment. Speed feedback control is substantially performed by feedback control (shifting based on the passage of time), and it is not necessary to detect whether or not the plunger 23 has reached the deceleration start position.

  Note that the plunger 23 and the injection motor 27 may be decelerated by the force received by the plunger 23 from the molten metal substantially filled in the mold 101 without performing such deceleration control of the injection motor 27.

(Inertial force control by flow control valve: t2 to t6)
The control device 13 controls (essentially reduces) the flow rate of the liquid discharged from the front chamber 48a by the auxiliary valve 61 in an appropriate period including the time immediately before the stop of the plunger 23, and as a result, the plunger 23 and the injection The inertial force forward of the drive unit 25 is controlled (essentially reduced). Thereby, for example, the possibility that a large surge pressure is generated is reduced. This operation also contributes to the deceleration control of the plunger 23.

  Specifically, for example, the control device 13 decreases the flow rate before the plunger stops. Then, the flow rate is minimized at the stop point (t4) of the plunger 23, and thereafter the flow rate is maintained. Here, when the flow rate is set to the minimum, the auxiliary valve 61 is not fully closed, and absorption of pressure fluctuations from the front chamber 48a to the accumulator 57 is allowed.

  The start time and end time of the flow rate control may be set as appropriate. FIG. 4 illustrates a case where the flow rate control is started relatively early after the start of high-speed injection (in another aspect, after the start of driving of the pressure-increasing electric motor 29) and before the start of deceleration. Therefore, the decrease in the flow rate is proceeding relatively slowly. As a result, for example, the possibility that an unintended pressure fluctuation occurs due to an impact applied to the pressure member 47 is reduced.

(Stop of plunger: t4)
The plunger 23 is stopped by the deceleration control of the injection motor 27 described above and / or by the force that the plunger 23 receives from the molten metal (t4). At this time, since the auxiliary valve 61 is not completely closed, the pressure fluctuation in the front chamber 48 a is absorbed by the accumulator 57. As a result, the generation of surge pressure as shown by the dotted line in FIG. 4 is suppressed.

(Pressure increase: t3 to t4)
As described above, the pressure-increasing electric motor 29 starts rotating at an appropriate time and reaches a certain rotational speed _MVI . The time at which the rotational speed _MVI is reached may be an appropriate time, but is, for example, the time (t3) at which deceleration is started. As a result of the deceleration of the plunger 23, when the advance speed of the joint piston 41 becomes slower than the advance speed of the pressure member 47, the volume between the joint piston 41 and the pressure member 47 is reduced. On the other hand, the control device 13 closes the head-side valve 59 at an appropriate time after starting deceleration and before stopping the plunger (in the illustrated example, at the time of starting deceleration).

  As a result, the pressure in the head side chamber 39h increases. As a result, the driving force of the pressure-increasing electric motor 29 is transmitted to the plunger 23 via the pressure member 47, the liquid in the head side chamber 39h, and the coupling piston 41. That is, pressure increase by the driving force of the pressure increasing motor 29 is realized.

Then, the injection pressure reaches the pressure P _max which is the final pressure (t4). The pressure increase time until the pressure P _max is reached can be set to an arbitrary length by appropriately controlling the injection motor 27 and the pressure increase motor 29, similarly to the acceleration time and deceleration time. Similarly, by setting the injection motor 27 and the pressure-increasing motor 29 to be low-inertia motors, the setting of such a boosting time is suitably performed. For example, the pressure increase from P _H = 3 MPa to P _max = 50 MPa can be performed in about 10 ms.

  In the pressure increase, the control device 13 may appropriately perform speed control and / or torque control of the pressure increase motor 29. For example, the control device 13 may switch the control of the pressure-increasing motor 29 from speed control to torque control at an appropriate time such as the deceleration start time, or may perform control combining speed control and torque control. .

  The speed control may be an open control or a feedback control, and the feedback control may be based on a deviation of the speed itself or based on a momentary positional deviation. Also good. Further, the speed control may be performed by a semi-closed loop based on the detection value of the rotation sensor 29s of the pressure-increasing electric motor 29, and the speed (position) of the pressurizing member 47 including or not including this loop may be used. It may be based on a (full) closed loop made by providing a sensor for detection.

  The torque control may be open control or feedback control. The feedback control may be based on a semi-closed loop based on the current of the pressure-increasing motor 29 detected by a current detector (not shown), or based on a detection value of the force sensor 99 including or not including this loop. It may be a closed loop. Further, the torque of the pressure-increasing electric motor 29 may be controlled in multiple stages.

(Holding pressure: t4 to t6)
After the plunger 23 is stopped (t4), the injection motor 27 is in a torque-free state, for example. For example, the pressure-increasing electric motor 29 is stopped or torque control is maintained. By retreating the pressurizing member 47 and discharging the liquid in the head side chamber 39h by the head side valve 59, or in addition to this, maintaining the torque control of the pressure increasing motor 29. The casting pressure P _max is maintained.

In holding pressure, the pressure in the cavity Ca can be maintained at the casting pressure P _max by advancing the plunger 23 appropriately (speed V ₁ ) by the pressure-increasing electric motor 29 according to the shrinkage accompanying the solidification of the molten metal. When a certain time has elapsed, the torque of the pressure-increasing electric motor 29 is gradually reduced, and further, the pressure-increasing electric motor 29 is stopped and the pressure holding is completed (t6).

  In the holding pressure, the retraction of the pressurizing member 47 may be regulated by a servo lock function or a brake of the pressure-increasing electric motor 29 and / or by the resistance force of the pressure-increasing screw mechanism 83 (slide screw mechanism). May be made.

(After molding)
When the molded product is solidified, the mold is opened by a mold clamping device (not shown), and the molded product is pushed out of the mold by an extrusion device (not shown). The injection device 9 may extrude the biscuits with the plunger 23 in order to release the molded product from the fixed mold 103. The electric motor used at this time may be either the injection electric motor 27 or the pressure-increasing electric motor 29, or both of them may be used.

  Thereafter, the joint piston 41 is returned to the initial position by the reverse rotation of the injection motor 27, and the pressure member 47 is returned to the initial position by the reverse rotation of the pressure-increasing motor 29. At this time, the head side valve 59 and the auxiliary valve 61 are opened. Therefore, the liquid discharged from the head side chamber 39h by the retreat of the joint piston 41 is returned to the front side chamber 48a via the communication channel 55. The excess or deficiency of the liquid is eliminated by the accumulator 57.

  As described above, in the present embodiment, the injection device 9 includes the injection motor 27, the pressure-increasing motor 29, and the integrated transmission mechanism 31 interposed between these and the plunger 23. The integrated transmission mechanism 31 is located behind the plunger 23, and includes a joint piston 41 that moves together with the plunger 23 when the driving force of the injection motor 27 is transmitted without passing through the fluid pressure device, and the joint piston 41. A cylinder member 39 having a head side chamber 39h filled with a liquid on the rear side of the coupling piston 41 and a pressure-increasing motor 29 is driven without a fluid pressure device. A pressurizing member 47 that pressurizes the liquid in the head side chamber 39h, and an auxiliary piston 46 fixed to the joint piston 41 and slidably accommodated in the joint piston 41. An auxiliary cylinder chamber 48 having a front chamber 48a filled with liquid is provided on the front side of the auxiliary piston 46.

  Therefore, for example, when the plunger 23 is driven by the injection motor 27, the pressure-increasing motor 29 is substantially separated from the plunger 23 by allowing the joint piston 41 and the pressure member 47 to be separated. The plunger 23 can be driven in the state. On the other hand, when the pressurizing member 47 is advanced by the pressure-increasing motor 29, the driving force of the pressure-increasing motor 29 is transmitted to the plunger 23 due to an increase in the pressure of the liquid in the head side chamber 39h. Is substantially connected to the plunger 23. That is, the electric motor that drives the plunger 23 can be switched.

  Such switching of the electric motor using the cylinder mechanism 33 is advantageous in transmitting a large force compared to, for example, a case where a friction clutch is used. Further, for example, the liquid in the head side chamber 39h and / or the front side chamber 48a contributes to various impact relaxations, so that an improvement in durability is expected. For these reasons, the present embodiment is advantageous for all-electrical use of a large molding machine that requires a relatively large driving force and that the inertial force tends to be relatively large.

  Further, by providing the auxiliary piston 46 and the auxiliary cylinder chamber 48, a configuration is obtained in which the liquid is discharged as the plunger advances. That is, the front chamber 48a produces the same action as the action of the rod side chamber (rod side chamber filled with liquid) of a general hydraulic cylinder with respect to the action of the liquid. Therefore, various advantageous effects can be obtained by using the front chamber 48a. For example, impact relaxation, inertial force control, and / or deceleration control can be performed. In another aspect, the necessity of filling the rod side chamber 39r with liquid is reduced, and the rod side chamber 39r can be effectively used, for example, by arranging a part of the transmission mechanism 35 for injection in the rod side chamber 39r.

  In the present embodiment, the integrated transmission mechanism 31 further includes a communication channel 55 that communicates the head side chamber 39h and the front chamber 48a.

  Accordingly, for example, liquid can be replenished from the front chamber 48a whose volume is reduced as the auxiliary piston 46 is advanced with respect to the head side chamber 39h whose volume is increased as the joint piston 41 is advanced. Conversely, the liquid discharged from the head side chamber 39h can be stored in the front side chamber 48a. That is, the auxiliary piston 46 and the auxiliary cylinder chamber 48 can be effectively used to eliminate excess and deficiency of the liquid in the head side chamber 39h. In another aspect, since the liquid is replenished between the head side chamber 39h and the front side chamber 48a, the volume of the liquid as a whole apparatus is reduced, and the apparatus can be downsized.

  In the present embodiment, the integrated transmission mechanism 31 includes an accumulator 57 that communicates with the front chamber 48a.

  Therefore, for example, the pressure fluctuation generated in the front chamber 48a when the plunger 23 is stopped can be released to the accumulator 57, and the surge pressure can be suppressed. Further, the accumulator 57 can eliminate excess or deficiency of the liquid in the cylinder mechanism 33.

  Moreover, in this embodiment, the integrated transmission mechanism 31 has the auxiliary | assistant valve | bulb 61 (flow control valve) which can control the flow volume of the liquid discharged | emitted from the front side chamber 48a.

  Therefore, for example, the inertial force immediately before the plunger 23 is stopped can be controlled by controlling the flow rate of the liquid discharged from the front chamber 48a, thereby suppressing the surge pressure.

  In the present embodiment, the pressurizing member 47 is positioned behind the joint piston 41 with the head side chamber 39h interposed therebetween. At least a part of the auxiliary cylinder chamber 48 is located in the pressure member 47.

  Therefore, for example, the pressurizing member 47 and the auxiliary piston 46 are arranged concentrically, and the size can be reduced. From another viewpoint, the pressurizing member 47 for pressurizing the liquid in the head side chamber 39h is used for forming the auxiliary cylinder chamber 48, and the pressurizing member 47 is effectively used. In addition, the pressure member 47 and the liquid in the front chamber 48a exert pressure on each other, and the impact is expected to be dispersed.

  In the present embodiment, the pressure-increasing electric motor 29 is a rotary type. The integrated transmission mechanism 31 (the pressure increase transmission mechanism 37) is screwed to the screw shaft 87 coaxially fixed to the pressure member 47 and the screw shaft 87, and the rotation of the pressure increase motor 29 is transmitted. And a nut 85 to be provided. The auxiliary cylinder chamber 48 extends in the pressure member 47 and the screw shaft 87. The movable range of the auxiliary piston 46 extends over the pressure member 47 and the screw shaft.

  Therefore, for example, the pressurizing member 47 and the screw shaft 87 are arranged coaxially, and the auxiliary piston 46 is arranged concentrically with the pressurizing member 47 and the screw shaft 87, thereby reducing the size. It is done. In another aspect, the screw shaft 87 for converting the rotation of the pressure-increasing electric motor 29 into a translational motion and transmitting it to the pressurizing member 47 is used for forming the auxiliary cylinder chamber 48. Can be used effectively.

  In the present embodiment, the injection motor 27 and the pressure-increasing motor 29 are rotary, and the integrated transmission mechanism 31 converts the rotation of the injection motor 27 into a translational motion to convert the plunger 23 (strictly, the front rod 43). ) And a pressure increasing screw having a large diameter and a small lead compared to the injection screw mechanism 69 that converts the rotation of the pressure increasing motor 29 into a translational motion and transmits it to the pressurizing member 47. A mechanism 83 is further provided.

  Therefore, since the driving force is transmitted from the injection motor 27 and the pressure-increasing motor 29 by a screw mechanism, for example, a relatively large driving force can be easily transmitted, and it is easy to cope with a large die casting machine. In addition, since the lead of the injection screw mechanism 69 is relatively large, for example, when the plunger 23 is driven by the injection motor 27, the speed can be easily increased. On the other hand, since the lead of the pressure-increasing screw mechanism 83 is relatively small, for example, when the pressure member 47 is driven by the pressure-increasing electric motor 29, it is easy to increase the thrust. Further, since the diameter of the pressure-increasing screw mechanism 83 is relatively large, for example, when the pressure member 47 is driven by the pressure-increasing electric motor 29, the screw shaft 87 of the pressure-increasing screw mechanism 83 is unlikely to buckle. Easy to transmit relatively large thrust.

Second Embodiment
In the following description of the second embodiment, differences from the first embodiment will be mainly described. The points not particularly mentioned are the same as in the first embodiment. About the structure which is the same as that of 1st Embodiment, or similar, the code | symbol attached | subjected to the structure of 1st Embodiment may be attached | subjected, and description may be abbreviate | omitted. About the structure which is similar (corresponding) to the structure of the first embodiment, even when the reference numerals different from those of the first embodiment are attached, the matters not particularly noted are the same as those of the first embodiment. .

  FIG. 5 is a view similar to FIG. 2 showing the configuration of the injection device 209 (injection drive unit 225) according to the second embodiment. However, in FIG. 5, a cross-sectional view corresponding to the line AA is also shown in the upper left of the drawing.

(Schematic configuration of injection drive)
Similarly to the injection device 9 of the first embodiment, the injection device 209 includes an injection motor 27, a pressure-increasing motor 29, and an integrated transmission mechanism 231 that transmits these driving forces to the plunger 23. 231 includes a cylinder mechanism 233, an injection transmission mechanism 235, and a pressure increase transmission mechanism 237.

(Basic configuration of cylinder mechanism)
The cylinder mechanism 233 includes a cylinder member 239, a joint piston 41, a front rod 243, and a pressure member 247, similarly to the cylinder mechanism 33 of the first embodiment. The inside of the cylinder member 239 is partitioned by a joint piston 41 into a rod side chamber 239r and a head side chamber 239h.

  However, in this embodiment, the pressurizing member 247 is not arranged behind or coaxially with the joint piston 41 and intersects the moving direction of the joint piston 41 (the front-rear direction of the injection device 209). The direction (for example, orthogonal) is arranged as the moving direction.

  In another aspect, the pressurizing member 247 does not have a piston shape that slides in the cylinder member 239 on which the joint piston 41 slides, but slides in the pressure-increasing cylinder member 240 connected to the cylinder member 239. It has a piston shape. The pressurizing member 247 can pressurize the liquid in the head side chamber 239h via the liquid in the pressure increasing cylinder member 240.

  The diameter of the pressure-increasing cylinder member 240 (pressure member 247) may be the same as or different from the diameter of the cylinder member 239 (joint piston 41). From the viewpoint of reducing the load on the pressure-increasing electric motor 29, the diameter of the pressure-increasing cylinder member 240 is preferably smaller than the diameter of the cylinder member 239.

  The pressure member 247 may slide only within the pressure-increasing cylinder member 240 or may enter the cylinder member 239 within a range not interfering with the auxiliary rod 45. In the illustrated example, the pressure-increasing cylinder member 240 is directly connected to the cylinder member 239, but may be connected via an appropriate flow path. In the illustrated example, the pressure-increasing cylinder member 240 is disposed so as to be orthogonal to the cylinder member 239, but may be disposed so as to be inclined or parallel to the cylinder member 239.

(Auxiliary part of cylinder mechanism)
The cylinder mechanism 233 includes an auxiliary rod 45, an auxiliary piston 246, and an auxiliary cylinder chamber 248, similarly to the cylinder mechanism 33 of the first embodiment. The auxiliary cylinder chamber 248 has a front chamber 248 a filled with liquid on the front side of the auxiliary piston 246.

  However, the auxiliary cylinder chamber 248 is not formed inside the pressurizing member and the screw shaft, but is formed inside the auxiliary cylinder member 252 connected to the cylinder member 239. The head side chamber 239h and the front side chamber 248a are partitioned by a partition portion 254 (which may be regarded as a rear end portion of the cylinder member 239 or a front end portion of the auxiliary cylinder member 252). The auxiliary rod 45 extends from the joint piston 41 to the auxiliary piston 246 through the partition portion 254. The diameter of the auxiliary piston 246 may be smaller than or equal to the joint piston 41 (example shown in the figure) or larger.

(Hydraulic system related to cylinder mechanism)
Similar to the integrated transmission mechanism 231 of the first embodiment, the integrated transmission mechanism 231 includes a liquid control unit 253 for controlling the flow of liquid related to the cylinder mechanism 233, and the liquid control unit 253 is a communication flow. A passage 55, an accumulator 57, a head side valve 259 and an auxiliary valve 261 are provided.

  Similarly to the head side valve 59 of the first embodiment, the head side valve 259 can allow a bidirectional flow between the head side chamber 239h and the front side chamber 248a, and at least from the head side chamber 239h to the front side chamber 248a. Flow (in another aspect, discharge of liquid from the head side chamber 239h) can be prohibited.

  However, in FIG. 5, a pilot type check valve is shown as the head side valve 259 instead of a non-leak switching valve. This check valve allows the flow from the front side chamber 248a to the head side chamber 239h when the pilot pressure is not introduced, and prohibits the flow in the opposite direction. When the pilot pressure is introduced, Allow both flows.

  The auxiliary valve 261 controls the flow rate of the liquid discharged from the front chamber 248a, similarly to the auxiliary valve 61 of the first embodiment. However, FIG. 5 shows a normal flow control valve as the auxiliary valve 61, not a non-leak switching valve with a flow control function. More specifically, this flow control valve has, for example, a pressure compensation function and a temperature compensation function, and is opened by sequentially operating electromagnetic force and pilot pressure.

  In FIG. 5, the liquid control unit 253 has a bypass valve 263. The bypass valve 263 is a check valve provided in a flow path that bypasses the auxiliary valve 261. That is, the auxiliary valve 261 and the bypass valve 263 constitute a flow control valve with a check valve.

  The bypass valve 263 prohibits the flow of liquid from the front chamber 248a to the head chamber 239h and allows the flow in the opposite direction in the flow path bypassing the auxiliary valve 261. Therefore, regardless of whether the auxiliary valve 261 is opened or closed, the flow from the accumulator 57 to the front chamber 248a and the flow from the head chamber 239h to the front chamber 248a through the opened head valve 259 are allowed.

  However, the bypass valve 263 may be omitted, and the flow to the front chamber 248a may be permitted by the control for opening the auxiliary valve 261 as in the first embodiment.

(Transmission mechanism for injection)
Similarly to the injection transmission mechanism 35 of the first embodiment, the injection transmission mechanism 235 converts the rotation of the injection motor 27 into a translational motion and transmits it to the plunger 23 (more strictly, the front rod 243). However, in the first embodiment, a screw mechanism is used as a mechanism for converting rotational motion into translational motion, whereas in this embodiment, a rack and pinion mechanism 269 is used. Note that the number of combinations of the injection motor 27 and the rack and pinion mechanism 269 may be one or two or more. In this embodiment, one case is taken as an example.

  The rack and pinion mechanism 269 includes a rack 273 and a pinion 271 that can mesh with the rack 273.

  The rack 273 is provided on the front rod 243. That is, the rack 273 is configured by arranging a plurality of teeth on the outer peripheral surface of the front rod 243 along the axial direction of the front rod 243. The position (upper surface, side surface, or lower surface) around the axis of the front rod 243 of the rack 273 may be set as appropriate. The pinion 271 is arranged such that a direction perpendicular to the axial direction of the front rod 243 (the paper surface penetration direction in FIG. 1) extends in the rotation axis. When the rotation of the injection motor 27 is transmitted to the pinion 271, the rack 273 moves in the axial direction of the front rod 243, and as a result, the plunger 23 moves forward and backward.

  The transmission of rotation from the injection motor 27 to the pinion 271 is performed directly, for example, without using a transmission mechanism. That is, the injection motor 27 is arranged so that its output shaft 27a is concentric with the pinion 271, and the output shaft 27a and the pinion 271 are fixed. However, rotation may be indirectly transmitted from the injection motor 27 to the pinion 271 via a transmission mechanism such as a winding transmission mechanism or a gear mechanism (including a bevel gear, for example).

(Transmission mechanism for pressure increase)
The pressure-increasing transmission mechanism 237 includes a winding transmission mechanism and a pressure-increasing screw mechanism 283, similarly to the pressure-increasing transmission mechanism 37 of the first embodiment.

  However, the screw shaft 287 of the pressure-increasing screw mechanism 283 does not have the auxiliary cylinder chamber 248 inside as described above. Further, in response to the pressurizing member 247 intersecting (for example, orthogonal to) the front-rear direction of the injection device 209, various rotary shafts of the pressure-increasing electric motor 29, the winding transmission mechanism, and the pressure-increasing screw mechanism 283. This direction intersects the direction of the rotation axis in the first embodiment.

(Operation of injection device)
FIG. 6 is a timing chart for explaining the operation of the injection device 209.

  This figure is the same as FIG. 2 except that the operation of the head side valve is omitted and the waveform indicating the operation of the auxiliary valve is different from FIG. That is, the operation of the injection device 209 may be the same as the operation of the injection device 9 of the first embodiment except for the control of these valves. Note that the head-side valve 259 is in a state where pilot pressure is not introduced, for example, in the illustrated range (from the start of injection to the completion of pressure holding).

(Before starting low-speed injection: ~ t0)
Immediately before the start of low-speed injection, unlike the first embodiment, the auxiliary valve 261 is, for example, fully open. As described above, for example, pilot pressure is not introduced into the head side valve 259.

  Accordingly, although the pressure is low, the pressure of the accumulator 57 is applied to the head side chamber 239h and the front side chamber 248a. As a result, for example, in a mode in which the cross-sectional area of the auxiliary piston 246 is smaller than the cross-sectional area of the joint piston 41, the joint piston 41 may move unintentionally. In the illustrated example, the auxiliary piston 246 and the joint piston 41 have the same cross-sectional area, and thus such unintended advance does not occur.

  It should be noted that unintended advancement is reliably prevented in the illustrated example, or unlike the illustrated example, unintended advancement is prevented in a mode in which the cross-sectional area of the auxiliary piston 246 is smaller than the cross-sectional area of the joint piston 41. Therefore, as in the first embodiment, the auxiliary valve 261 may be closed, or the head side valve 259 may be configured so that the flow of liquid from the accumulator 57 to the head side chamber 239h can be prohibited. Further, a servo lock function or a brake of the injection motor 27 may be used. Further, from the viewpoint of reliably preventing unintended advancement, the cross-sectional area of the auxiliary piston 246 may be larger than the cross-sectional area of the joint piston 41.

(Low speed injection, high speed injection and deceleration by injection motor: t0 to t4)
Operations for low speed injection, high speed injection, and deceleration by the injection motor may be the same as the operations in the first embodiment. The head side valve 259 allows the liquid to flow into the head side chamber 239h, and the auxiliary valve 261 is in an open state (for example, fully open). Therefore, the point that the liquid discharged from the front chamber 248a is returned to the head side chamber 239h as the joint piston 41 advances (the auxiliary piston 246 advances) is the same as in the first embodiment.

  However, in the example shown in FIG. 5, the diameter of the auxiliary piston 246 is equal to the diameter of the joint piston 41, so that excess or deficiency of the liquid does not occur if the influence of the pressurizing member 247 is ignored. As already described, unlike the illustrated example, the diameter of the auxiliary piston 246 may be larger or smaller than the diameter of the joint piston 41. The excess or deficiency of the liquid generated in this case is eliminated by the accumulator 57 as in the first embodiment.

(Inertial force control by flow control valve: t3 to t4)
As in the first embodiment, the control device 13 controls the flow rate of the liquid discharged from the front chamber 248a by the auxiliary valve 261 in an appropriate period including the time immediately before the plunger 23 is stopped (basically reduced). ) As a result, the inertial force forward of the plunger 23 and the injection drive unit 225 is controlled (basically reduced). However, FIG. 6 illustrates a case where the specific control method is different from that in FIG.

  For example, the control device 13 performs control to once again decrease the flow rate and then increase the flow rate again. The flow rate when it is most reduced may be set as appropriate, or may be zero. The flow rate most increased after the reduction may be set as appropriate, or may be the maximum (flow rate corresponding to full opening). The rate of change of the flow rate when the flow rate is decreased or increased, the start time point, the end time point, and the like may be set as appropriate. Such control is performed in an appropriate period from the start of deceleration (t3) to the stop of the plunger 23 (t4), for example.

  In FIG. 6, when the deceleration start condition is satisfied (t3), the flow rate is decreased at the maximum speed, and then the flow rate is gradually increased. When the plunger 23 is almost stopped (t4), it is assisted to be fully opened. The mode by which the valve 261 for control is controlled is illustrated.

(Plunger stop and pressure increase: t3 to t4)
The operation related to stopping and increasing the pressure of the plunger 23 may be basically the same as the operation of the first embodiment. However, if the speed of the pressurizing member 247 exceeds the speed of the joint piston 41 after the start of deceleration of the plunger 23 (t4), the head side valve 259 consisting of a check valve is self-closed. Further, the control for closing the head side valve 59 is unnecessary.

(After molding)
The operation after solidification of the molten metal is basically the same as the operation of the first embodiment. However, control for opening the head side valve 259 is performed by introducing pilot pressure. In the example of FIG. 5, since the bypass valve 263 is provided, the auxiliary valve 261 may be closed when replenishing the liquid to the front chamber 248a when the auxiliary piston 246 is retracted. In the example of FIG. 5, the sectional area of the joint piston 41 and the sectional area of the auxiliary piston 246 are equal. If the influence of the member 247 is ignored, excess or deficiency of the liquid does not occur.

  Also in the present embodiment, the injection device 209 includes the injection motor 27, the pressure-increasing motor 29, and the integrated transmission mechanism 231 interposed between these and the injection plunger, as in the first embodiment. Further, the integrated transmission mechanism 231 is located behind the joint piston 41 and accommodates the auxiliary piston 246 fixed to the joint piston 41 and the auxiliary piston 246 so as to be slidable. An auxiliary cylinder chamber 248 having a front chamber 248a filled with liquid is provided on the front side of the piston 246.

  Therefore, also in this embodiment, the same effect as the first embodiment is achieved. For example, the electric motor that drives the plunger 23 can be suitably switched without using a friction clutch. Moreover, various advantageous effects can be obtained by the front chamber 248a that produces the same action as that produced by the rod side chamber of a general hydraulic cylinder.

  In the first and second embodiments described above, the die casting machine 1 is an example of a molding machine, the injection motor 27 is an example of a first motor, and the pressure-increasing motor 29 is an example of a second motor, The integrated transmission mechanisms 31 and 231 are examples of transmission mechanisms, the plunger 23 is an example of an injection plunger, the communication flow path 55 is an example of a flow path, and the auxiliary valves 61 and 261 are examples of flow control valves, respectively. The injection screw mechanism 69 is an example of a first screw mechanism, and the pressure-increasing screw mechanism 83 is an example of a second screw mechanism and a screw mechanism.

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The first and second embodiments may be appropriately combined. For example, in the first embodiment, the fluid control unit (valve or the like) is that of the second embodiment, the injection transmission mechanism is that of the second embodiment, the pressurizing member and the auxiliary unit (auxiliary unit) A piston or the like) may be the second embodiment.

  The molding machine (molding machine) is not limited to a die casting machine. For example, the molding machine may be another metal molding machine, an injection molding machine that molds a resin, or a molding machine that molds a material in which a thermoplastic resin or the like is mixed with wood flour. There may be. Further, the molding machine is not limited to horizontal mold clamping horizontal injection, and may be vertical mold clamping vertical injection, horizontal mold clamping vertical injection, vertical mold clamping horizontal injection, for example. The molding material is not limited to a liquid material, and may be a solid-liquid coexisting state such as a semi-solid metal or a semi-molten metal. The liquid used for the cylinder mechanism is not limited to oil, and may be water, for example.

  The number of electric motors having different roles such as the injection electric motor 27 and the pressure-increasing electric motor 29 may be provided as appropriate, and is not limited to two. For example, a low-speed injection motor, a high-speed injection motor, and a pressure-increasing motor may be provided. Moreover, as mentioned in the embodiment, a plurality of electric motors having a common role may be provided. For example, two injection motors 27 may be provided, or two booster motors 29 may be provided.

  The division of roles of the first motor (injection motor 27 in the embodiment) that drives the piston and the second motor (increase motor 29 in the embodiment) that drives the pressurizing member may be set as appropriate. For example, the second motor may perform low-speed injection and pressure increase, and the first motor may perform high-speed injection. Further, for example, in the pressure increase and / or pressure holding, the torque control of the first motor may be performed in addition to the second motor, and pressure increase and / or pressure holding may be performed by the first motor and the second motor.

  Each of the first electric motor and the second electric motor is not limited to a rotary type, and may be a linear motor. In this case, a transmission mechanism for transmitting the driving force of the linear motor to the plunger (the front rod and the coupling piston) or the pressure member may not be provided. The rotary first electric motor may include a nut screwed into a screw shaft provided on the front rod as a rotor, and may be disposed concentrically with the front rod. , A part or all of them may be arranged in the cylinder member. Moreover, the 1st electric motor which consists of a linear motor may contain a front side rod as a needle | mover, and a part or all of such a 1st electric motor may be arrange | positioned in a cylinder member.

  In the case where the first electric motor or the second electric motor is a rotary type, the mechanism for converting the rotation into the translational motion is not limited to the screw mechanism and the rack and pinion mechanism. For example, a cam mechanism or a link mechanism may be used. In the screw mechanism, a nut may be fixed to the plunger, and the screw shaft may be rotated by an electric motor.

  The rotation transmission mechanism (for example, the winding transmission mechanism of the first embodiment) that transmits the rotation of the first or second electric motor without converting it into translational motion may or may not be provided. The rotation transmission mechanism may be a mechanism other than the winding transmission mechanism such as a gear mechanism.

  The injection device of the present embodiment reduces the necessity of disposing liquid in the rod side chamber by providing an auxiliary piston or the like, and enables effective use of the rod side chamber. However, the rod side chamber may be filled with liquid.

  Further, in relation to the above, the configuration for driving the plunger by the driving force of the first electric motor is not limited to the configuration for transmitting the driving force of the first electric motor to the front rod in the rod side chamber, and the rotation is translated. It is not limited to the structure where the mechanism etc. which convert to are arrange | positioned in a rod side chamber. For example, a screw mechanism or a rack and pinion mechanism may be provided in parallel to the front rod outside the cylinder member, and the mechanism may be connected to the plunger, the front rod, or a coupling that connects them.

  When the pressurizing member is positioned behind the joint piston, the auxiliary cylinder chamber may be formed only inside the pressurizing member or only inside the screw shaft. In the embodiment, the volume of the auxiliary cylinder chamber 48 is secured by forming the protruding portion 47b on the pressure member 47, but such a protruding portion 47b may not be provided. The pressure member in which the auxiliary cylinder chamber is formed does not need to have the screw shaft fixed coaxially. For example, in the first embodiment, the portion that is the screw shaft 87 may be a part of the pressure member that is not cut into the thread groove, and the screw shaft may be provided in parallel to the pressure member.

  The pressure member is not limited to a piston-shaped member. For example, in the second embodiment, the pressure member may have a rod shape having a diameter smaller than that of the pressure increasing cylinder member 240. Further, for example, the pressurizing member may be a rod that advances and retreats from the side surface of the cylinder member 239 so as not to interfere with the auxiliary rod 45 without the pressure increasing cylinder member 240 being provided.

  In the embodiment, the excess or deficiency of the liquid in the cylinder mechanism is solved by the accumulator. However, instead of the accumulator, for example, the excess or deficiency of the liquid may be eliminated by a tank. In this case, the shortage of liquid in the head side chamber or the front side chamber is replenished by, for example, sucking the liquid by the negative pressure in these cylinder chambers. Further, for example, excessive liquid may not be generated, and when the liquid is insufficient, a vacuum space may be formed in the head side chamber or the front side chamber.

  In the embodiment, the flow rate of the hydraulic fluid discharged from the front chamber is controlled in the period including the time immediately before the plunger stops, but such control may not be performed. For example, in the embodiment, the auxiliary valve 61 or 261 may not be provided, and the accumulator 57 may be directly connected to the front chamber. Even in this case, for example, the effect that the pressure fluctuation in the front chamber is absorbed by the accumulator 57 is exhibited.

  Further, as the auxiliary piston moves forward, the gap between the inner surface of the auxiliary cylinder chamber (front chamber) and the auxiliary piston becomes narrow, thereby reducing the flow rate of the liquid discharged from the front chamber. . For example, in the second embodiment, at the front end of the auxiliary cylinder chamber 248 (behind the port connected to the accumulator 57), a portion (tapered or stepped) that is smaller in diameter than the portion where the auxiliary piston slides. And a portion that can be inserted into the aforementioned reduced diameter portion may be formed at the front end of the auxiliary piston 246.

  A configuration for reducing surge pressure other than that shown in the embodiment may be combined with the configuration of the embodiment. For example, an elastic member and / or a liquid (for example, oil) interposed between the plunger and the front rod may be disposed in the coupling that connects the plunger and the front rod. When the liquid is disposed in the coupling, a flow path for allowing the liquid in the coupling to escape to the head side chamber may be provided in the front rod when a surge pressure is generated.

DESCRIPTION OF SYMBOLS 1 ... Injection device, 23 ... Plunger, 27 ... Electric motor for injection (1st electric motor), 29 ... Electric motor for pressure increase (2nd electric motor), 31 ... Integrated transmission mechanism (transmission mechanism), 39 ... Cylinder member, 41 ... For joints Piston 46 ... auxiliary piston 47 ... pressurizing member 48 ... auxiliary cylinder chamber.

Claims (9)

A first electric motor;
A second electric motor;
A transmission mechanism interposed between the electric motor and the injection plunger;
Have
The transmission mechanism is
A coupling piston, which is located behind the injection plunger, and the driving force of the first electric motor is transmitted without a fluid pressure device and moves together with the injection plunger;
A cylinder member that slidably accommodates the coupling piston, and has a head side chamber filled with liquid on the rear side of the coupling piston;
A pressure member that is driven by the second electric motor without a fluid pressure device and pressurizes the liquid in the head side chamber;
An auxiliary piston that is located behind the coupling piston and is fixed to the coupling piston;
An injection apparatus comprising: an auxiliary cylinder chamber that slidably accommodates the auxiliary piston and has a front chamber filled with a liquid on a front side of the auxiliary piston. The injection device according to claim 1, wherein the transmission mechanism further includes a flow path communicating the head side chamber and the front side chamber. The injection device according to claim 1, wherein the transmission mechanism includes an accumulator that communicates with the front chamber. The injection device according to any one of claims 1 to 3, wherein the transmission mechanism includes a flow rate control valve capable of controlling a flow rate of the liquid discharged from the front chamber. The pressurizing member is located behind the joint piston across the head side chamber,
The injection device according to any one of claims 1 to 4, wherein at least a part of the auxiliary cylinder chamber is located in the pressure member. The second electric motor is rotary;
The transmission mechanism is
A screw shaft fixed coaxially to the pressure member;
A nut that is screwed onto the screw shaft and to which rotation of the second electric motor is transmitted;
The auxiliary cylinder chamber extends in the pressure member and the screw shaft,
The injection device according to claim 5, wherein a movable range of the auxiliary piston extends over the pressure member and the screw shaft. The first motor and the second motor are rotary,
The transmission mechanism is
A first screw mechanism that converts rotation of the first electric motor into translational motion and transmits the translation to the injection plunger;
A second screw mechanism having a small diameter and a small lead as compared with the first screw mechanism, which converts the rotation of the second electric motor into a translational motion and transmits it to the pressure member. The injection device according to any one of 1 to 5. The injection device according to claim 1, wherein a liquid is not filled in a front side of the joint piston in the cylinder member. The injection device according to any one of claims 1 to 8,
A mold clamping device for clamping the mold;
An extrusion device for extruding a molded product from the mold;
Having a molding machine.

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