JP2018030135A - Injection device and molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection device which can suitably drive a plunger by an electric motor.SOLUTION: An injection device 9 has a rotary type electric motor 27 for injection, an electric motor 29 for pressure-boosting, and an integration transfer mechanism 31 which transfers a driving force of the electric motor 27 for injection and the electric motor 29 for pressure-boosting, to the plunger 23. The integration transfer mechanism 31 has: a piston 41 fixed to the plunger 23 in the rear part of the plunger 23; a cylinder member 39 which stores the piston 41 in a slidable manner and has a head side chamber 39h that fills the rear side of the piston 41 with liquid; a screw mechanism 69 for injection which is arranged in parallel to the cylinder member 39, and converts the rotation of the electric motor 27 for injection into linear motion and transmits the linear motion to the piston 41; and a pressurization member 47 which is driven by the electric motor 29 for pressure-boosting not through a fluid compressor and pressurizes the liquid of the head side chamber 39h.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 and 2). 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.

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 rotary first electric motor, a second electric motor, and a transmission mechanism that transmits a driving force of the first electric motor and the second electric motor to an injection plunger, The transmission mechanism includes a piston fixed to the injection plunger behind the injection plunger, and a slidable housing for the piston, and a head side chamber filled with liquid on the rear side of the piston. A first screw mechanism that is arranged in parallel to the cylinder member, converts the rotation of the first electric motor into a linear motion and transmits the linear motion to the piston, and fluid is generated by the second electric motor. A pressure member that is driven without a pressure device and pressurizes the liquid in the head side chamber.

  Preferably, the second motor is a rotary type, and the transmission mechanism is larger than the first screw mechanism that converts the rotation of the second motor into a linear motion and transmits the linear motion to the pressure member. A second screw mechanism having a small diameter and a small lead is further provided.

  Preferably, the second electric motor is a rotary type, and the cylinder member includes a rod side chamber filled with a liquid on a front side of the piston, and the transmission mechanism converts the rotation of the second electric motor into a linear motion. A second screw mechanism that transmits to the pressure member; a front rod that extends from the piston to the outside of the rod side chamber via the rod side chamber; and is connected to the injection plunger; A rear rod extending to the outside of the head side chamber via the head side chamber; and a flow path communicating the rod side chamber and the head side chamber; and the pressure member is disposed behind the piston. The second screw mechanism includes a screw shaft extending rearward from the pressure member, and a nut screwed to the screw shaft and rotated by the second electric motor, and the pressure member as well as The serial screw shaft, hole the rear rod is inserted is formed.

  Preferably, the cylinder member includes a rod side chamber filled with a liquid on a front side of the piston, and the transmission mechanism includes an accumulator communicating with the rod side chamber.

  Preferably, the cylinder member includes a rod side chamber filled with liquid on a front side of the piston, and the transmission mechanism includes a flow rate control valve capable of controlling a flow rate of the liquid discharged from the rod side chamber. Yes.

  Preferably, the cylinder member includes a rod-side chamber filled with a liquid on a front side of the piston, and the cylinder member has a sliding portion in which an inner diameter is constant in the axial direction and the piston slides, and the rod-side chamber. And a cushion portion having an inner diameter smaller than that of the sliding portion, the piston being a body that slides on the sliding portion. And a flow path cross-sectional area from the sliding part to the port in the gap with the cushion part by insertion into the cushion part. And a tip end portion that can be made smaller than the cross-sectional area.

  The molding machine which concerns on 1 aspect 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. 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 schematic diagram which shows the principal part structure of the injection device which concerns on 3rd Embodiment of this invention. The schematic diagram which shows the principal part structure of the injection device which concerns on 4th Embodiment of this invention. FIG. 7A and FIG. 7B are schematic views showing a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the second and subsequent embodiments, components that are the same as or similar to the configurations of the embodiments that have already been described may be denoted by reference numerals assigned to the configurations of the embodiments that have already been described, and descriptions thereof may be omitted. is there. Even when a configuration similar to (corresponding to) the configuration of the embodiment already described is denoted by a reference numeral different from that of the embodiment already described, matters that are not particularly noted are the same as those of the configuration of the embodiment already described. It is the same.

<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 is provided in a control panel and an operation unit 19 (not shown), for example. 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 view from above, a part (for example, a hydraulic system) is not limited to this for convenience of illustration. 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 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 (not shown) that detects its rotation, and the rotation speed is feedback-controlled by a servo driver (not shown) based on the detection value of the rotation sensor. 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. The injection motor 27 and the pressure-increasing motor 29 are within the front range from the rear end of the cylinder mechanism 33 (for example, the rear end of a rear rod 45 (described later) that is positioned in the backward limit). 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. They are arranged at approximately symmetrical positions. However, the two injection motors 27 may be arranged symmetrically with respect to the cylinder mechanism 33 in a plan view, and the pressure-increasing motor 29 may be arranged below or above the cylinder mechanism 33.

(Cylinder mechanism)
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 includes a cylinder member 39, a piston 41 slidably accommodated in the cylinder member 39, and is fixed to the piston 41, and the moving direction of the piston 41 from the cylinder member 39 is A front rod 43 extending to one side (front) of the front rod 43, a rear rod 45 fixed to the piston 41 and extending to the opposite side (rear) of the front rod 43, and a position behind the piston 41 And a pressure member 47 to be used.

  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 behind the piston 41 (for example, oil) can be pressurized and the plunger 23 can be driven.

  Of the cylinder member 39, the front side of the piston 41 and the configuration of the piston 41 and the front rod 43 may be the same as those of a general injection cylinder. For example, the piston 41 is generally cylindrical. 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 the 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. These two cylinder chambers are filled with liquid. 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. Note that the configuration of the frame 51 may be appropriately modified from a general one so that the injection transmission mechanism 35 and the like are suitably attached.

  The rear rod 45 is, for example, substantially circular in cross section like the front rod 43, and extends with a substantially constant cross sectional shape. The rear rod 45 extends through the pressure member 47 and the like to the outside of the head side chamber 39h. The cross-sectional area (diameter) of the rear rod 45 may be appropriately set as long as it is smaller than the cross-sectional area (diameter) of the piston 41. For example, it may be smaller than the cross-sectional area (diameter) of the front rod 43. It may be the same or larger. A suitable magnitude relationship between the two will be referred to later when the operation of the rear rod 45 is described later. In the illustrated example, the cross-sectional area of the rear rod 45 is equal to the cross-sectional area of the front rod 43.

  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.

  The pressure member 47 is formed with a hole 47h through which the rear rod 45 is inserted. The rear rod 45 is slidable with respect to the inner peripheral surface of the hole 47h. From another viewpoint, the end surface (the surface on the right side of the drawing) of the rear rod 45 is isolated from the head side chamber 39h by the pressing member 47. The hole 47h is, for example, a through hole that penetrates the pressing member 47 in the moving direction.

  The pressurizing member 47 may be in contact with the inner side of the rear end surface of the cylinder member 39 to define the retreat limit. In the middle of the rear rod 45, a stopper 45s may be provided that contacts the front surface of the pressure member 47 and restricts the proximity of the piston 41 and the pressure member 47 beyond a certain level. The stopper 45s is formed in a flange shape, for example. The retreat limit of the piston 41 may be defined by restricting the retreat with respect to the pressurizing member 47 by the stopper 45 s and defining the retreat limit of the pressurizing member 47 by the cylinder member 39. It may be defined by a stopper (not shown) that is provided and contacts the piston 41.

(Hydraulic system related to cylinder mechanism)
The integrated transmission mechanism 31 has a liquid control unit 53 for controlling the flow of liquid related to the cylinder mechanism 33. The liquid control unit 53 communicates with, for example, a communication channel 55 that connects the rod side chamber 39r and the head side chamber 39h, and an accumulator 57 that is connected to the rod side chamber 39r and / or the head side chamber 39h (both in the present embodiment). A head side valve 59, a flow rate control valve 61, and an auxiliary valve 63 provided in the flow path 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. One end of the communication channel 55 communicates with the rod side chamber 39r in front of the forward limit of the piston 41, and the other end communicates with the head side chamber 39h behind the backward limit of the piston 41. By providing the communication flow path 55, when the piston 41 moves forward, the liquid discharged to the head side chamber 39h whose volume is increased by the liquid discharged from the rod side chamber 39r as the volume of the rod side chamber 39r decreases. Can be replenished. Similarly, when the piston 41 moves backward, liquid can be supplied to the rod side chamber 39r with the liquid discharged from the head side chamber 39h.

  The amount of change in the volume of the rod-side chamber 39r accompanying the movement of the piston 41 is the magnitude obtained by multiplying the cross-sectional area obtained by subtracting the cross-sectional area of the front rod 43 from the cross-sectional area of the piston 41 by the amount of movement of the piston 41. The amount of change in the volume of the head-side chamber 39h accompanying the movement of the piston 41 is the magnitude obtained by multiplying the cross-sectional area obtained by subtracting the cross-sectional area of the rear rod 45 from the cross-sectional area of the piston 41 by the movement amount of the piston 41. Therefore, the difference between the amount of change in the volume of the rod side chamber 39r and the amount of change in the volume of the head side chamber 39h compared to the aspect in which the rear rod 45 is not provided due to the provision of the rear rod 45 is as follows. Alleviated. As a result, the excess or deficiency of the liquid when the liquid is replenished between the rod side chamber 39r and the head side chamber 39h by the communication channel 55 as described above is alleviated.

  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 piston 41 by liquid delivery, and its pressure 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 rod side chamber 39r and the head side chamber 39h. However, as will be understood from the operation described later, the accumulator 57 does not necessarily need to communicate with the head side chamber 39h, and may be connected to the rod side chamber 39r 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 rod side chamber 39r and the head side chamber 39h, and at least a flow from the head side chamber 39h to the rod side chamber 39r (another viewpoint). Then, the discharge of the liquid from the head side chamber 39h) can be prohibited. For example, the head side valve 59 is constituted by a pilot type check valve. When the pilot pressure is not introduced, the head side valve 59 allows a flow from the rod side chamber 39r to the head side chamber 39h and flows in the opposite direction. When the pilot pressure is introduced, both flows are allowed. Further, the head side valve 59 is provided in the communication channel 55 on the head side chamber 39 h side from the connection position of the communication channel 55 and the accumulator 57.

  By stopping the introduction of pilot pressure to the head side valve 59 and prohibiting the discharge of liquid from the head side chamber 39h by the head side valve 59, for example, the driving force of the pressure-increasing electric motor 29 is transmitted to the pressure member 47. When the pressurizing member 47 is moved forward, the pressure in the head side chamber 39h can be increased, and a force in the forward movement direction can be applied to the piston 41. That is, the driving force of the pressure-increasing electric motor 29 can be transmitted to the plunger 23. At this time, the pressure in the rod side chamber 39r is released to the accumulator 57, for example.

  The flow rate control valve 61 is for controlling the flow rate of the liquid discharged from the rod side chamber 39r. By controlling the flow rate of the liquid from the rod side chamber 39r, the speed of the piston 41 can be controlled, and consequently the inertial force in the forward direction at the time of injection can be controlled. For example, in the communication channel 55, the flow control valve 61 is provided closer to the rod side chamber 39 r than the connection position between the communication channel 55 and the accumulator 57.

  The flow control valve 61 may be, for example, a valve that performs pressure compensation (a flow rate adjusting valve) or a valve that does not perform pressure compensation. Further, the flow control valve 61 may perform temperature compensation or may not perform temperature compensation. The control method of the flow control valve 61 may be, for example, a spring type, an electromagnetic type, a pilot type, or a combination of two or more thereof. The flow control valve 61 may be a servo valve that performs feedback control or a proportional valve that performs open control. FIG. 2 shows a flow rate control valve 61 having a pressure compensation function and a temperature compensation function, which is opened by sequentially operating electromagnetic force and pilot pressure.

  The auxiliary valve 63 is a check valve provided in a flow path that bypasses the flow control valve 61. That is, the flow control valve 61 and the auxiliary valve 63 constitute a flow control valve with a check valve. The auxiliary valve 63 prohibits the flow of liquid from the rod side chamber 39r to the head side chamber 39h in the flow path bypassing the flow control valve 61 and allows the flow in the opposite direction. Therefore, regardless of whether the flow control valve 61 is opened or closed, the flow from the accumulator 57 to the rod side chamber 39r and the flow from the head side chamber 39h to the rod side chamber 39r through the opened head side valve 59 are allowed. However, the auxiliary valve 63 may be omitted, and the flow control valve 61 may be appropriately controlled to allow the flow to the rod side chamber 39r.

(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, A screw shaft 73 screwed into the nut 71, a guide shaft 75 fixed to the screw shaft 73, and a connecting plate 77 for fixing the guide shaft 75 and the coupling 49 are provided. 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 example shown in the drawing, the diameters of both are substantially equal. 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 linear 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 injection screw mechanism 69 is disposed in parallel with the cylinder mechanism 33, for example, and is within a range in front of the rear end of the cylinder mechanism 33.

  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 fixed to the screw shaft 73 via the guide shaft 75 or the like moves in the front-rear direction. For example, the nut 71 is allowed to rotate around the axis and is restricted from moving in the axial direction by, for example, the nut 71 being supported by an appropriate bearing. The rotation of the screw shaft 73 is regulated, for example, by the screw shaft 73 being connected to the front rod 43 via the guide shaft 75 and the connecting plate 77.

  For example, the guide shaft 75 is coaxially fixed to the front end of the screw shaft 73 and is interposed between the screw shaft 73 and the connecting plate 77. By providing the guide shaft 75, the screw shaft 73 and / or, for example, compared to an embodiment in which the tip of the screw shaft 73 is directly fixed to the connecting plate 77 (this embodiment is also included in the present invention). The injection motor 27 can be positioned rearward. As a result, for example, it is possible to reduce the risk that molten metal splashes reach the screw shaft 73 and / or the injection motor 27.

  For example, the guide shaft 75 is inserted into a bush provided on a fixed member (for example, the frame 51) and guided in the axial direction thereof. Therefore, the guide shaft 75 also contributes to reducing the possibility that an unnecessary moment (around the axis orthogonal to the plunger 23) is transmitted to the plunger 23 by the driving force of the injection motor 27. When the guide shaft 75 is not provided, the screw shaft 73 may be guided to the frame 51.

  A guide shaft 75 is also shown on the upper side of the drawing in FIG. The guide shaft 75 on the upper side of the paper surface may be used to reduce the possibility of unnecessary moment being applied to the plunger 23 simply by being guided by the bush of the frame 51. Similarly, it may be driven by fixing the screw shaft 73 to the rear end thereof. In the latter case, the two guide shafts 75 may be driven by one injection motor 27, or may be driven by separate injection motors 27, respectively. When two injection motors 27 are provided, tandem control (master-slave control) may be performed.

  The guide shaft 75 is made of a member different from the screw shaft 73 and may be fixed to the screw shaft 73, or may be fixed to the screw shaft 73 by being formed integrally with the screw shaft 73. . The length of the guide shaft 75 may be set so that the guide shaft 75 can slide with respect to the bush of the frame 51 with a stroke equivalent to the stroke of the piston 41, and / or the rear end of the screw shaft 73 is It may be set so as not to protrude rearward from the rear end of the cylinder mechanism 33.

  The connecting plate 77 may have an appropriate shape as long as the screw shaft 73 (strictly, the guide shaft 75) and the front rod 43 (strictly, the coupling 49) can be connected, and the fixing method thereof is also appropriately selected. It's okay. For example, the connecting plate 77 is located in front of the frame 51 and is fixed to the rear end surface of the coupling 49 with a screw (not shown) or the like, and a screw (reference numeral omitted) is inserted from the front to guide. It is fixed to the guide shaft 75 by being screwed to the front end of the shaft 75.

(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 a linear 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. For example, the pressure-increasing screw mechanism 83 is arranged in parallel to the cylinder mechanism 33, and is within a range in front of the rear end of the cylinder mechanism 33.

  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 of the screw shaft 87 is regulated by, for example, a guide in which the screw shaft 87 is eccentrically fixed to the pressurizing member 47 or a spline groove (not shown) provided in the screw shaft 87 is provided in the cylinder member 39. It is done by being guided and / or provided with a suitable anti-rotation member (see a third embodiment (FIG. 5) described later).

  The screw shaft 87 has a hole 87h through which the rear rod 45 is inserted. The hole 87h is, for example, a through hole that penetrates the screw shaft 87, and one end communicates with the hole 47h of the pressure member 47, and the other end is open to the atmosphere. And the end surface of the rear side rod 45 is exposed to atmospheric pressure by being inserted in the holes 47h and 87h. The inner diameter of the hole 87h of the screw shaft 87 is larger than the outer diameter of the rear rod 45, for example, so that both do not slide.

  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.

(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 of the pressure increasing motor 29, the detection signal of the current detector that detects the current flowing through the pressure increasing motor 29, and the opening degree of the flow control valve 61 A detection signal or the like that is shown 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 output to these control objects (strictly, its driver) in order to control, for example, the injection motor 27, the pressure-increasing motor 29, the flow control valve 61, and the display device 15. Control signal.

  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 guide shaft 75, and the position sensor 97 is located behind 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. 3 is a timing chart for explaining the operation of the injection device 9.

In FIG. 3, 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 flow control valve 61.

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 piston 41 (the plunger 23 and the 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. For example, pilot pressure is not introduced into the head side valve 59. The flow control valve 61 is fully opened, for example.

  In the above state, although the pressure is low, the pressure of the accumulator 57 is applied to the rod side chamber 39r and the head side chamber 39h. Therefore, for example, in a mode in which the cross-sectional area of the rear rod 45 is smaller than the cross-sectional area of the front rod 43, the piston 41 may move forward unintentionally. In the illustrated example, since the cross-sectional areas of the front rod 43 and the rear rod 45 are equal, such unintended advance does not occur.

  It should be noted that unintentional 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 rear rod 45 is smaller than the cross-sectional area of the front rod 43. For this purpose, the flow control valve 61 is closed, the head side valve 59 is configured so that the flow of liquid from the accumulator 57 to the head side chamber 39h can be prohibited, or the servo lock function or the brake of the injection motor 27 is used. You may do it.

(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 plunger 23 (the front rod 43 and the piston 41) via the injection transmission mechanism 35, and the plunger 23 moves forward. That is, low speed injection is performed by the driving force of the injection motor 27.

  At this time, the liquid discharged from the rod side chamber 39r as the piston 41 moves forward is returned to the head side chamber 39h. If the cross-sectional areas of the front rod 43 and the rear rod 45 are equal, basically, excess or deficiency of liquid does not occur. Further, when the cross-sectional areas of the front rod 43 and the rear rod 45 are different from each other and the liquid is excessive or insufficient, the excess or shortage is eliminated by the accumulator 57.

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. 3, 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 3, 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 forward speed of the pressurizing member 47 during high-speed injection is lower than the forward speed (V _H ) of the piston 41 and does not affect the control of the high-speed injection speed V _H by controlling the rotation speed of the injection motor 27. Or it has little 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: t3 to t4)
The control device 13 controls the flow rate of the liquid discharged from the rod side chamber 39r by the flow rate control valve 61 at an appropriate time in the period from the start of the deceleration of the plunger 23 to the stop of the plunger 23 (basic In other words, the inertial force forward of the plunger 23 and the injection drive unit 25 is controlled (basically reduced). Thereby, for example, the possibility that a large surge pressure is generated is reduced. This operation is also the deceleration control of the plunger 23.

  Specifically, for example, the control device 13 performs control to increase the flow rate again after once reducing the flow rate. 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.

  In FIG. 3, when the above-described deceleration start condition is satisfied (t3), the flow rate is decreased at the maximum speed, and then the flow rate is gradually increased so that the plunger 23 is fully opened (t4) so as to be fully opened. Fig. 6 illustrates a mode in which the flow control valve 61 is controlled.

(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 flow control valve 61 is opened (for example, fully open), the pressure fluctuation in the rod side chamber 39r is absorbed by the accumulator 57. As a result, the generation of surge pressure as shown by the dotted line in FIG. 3 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 piston 41 becomes slower than the advance speed of the pressure member 47, the volume between the piston 41 and the pressure member 47 is reduced. As a result, the head side valve 59 is self-closed, and 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 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. The speed control may be based on a semi-closed loop based on the detection value of the rotation sensor of the pressure-increasing electric motor 29, or the speed (position) of the pressure member 47 including or not including this loop is detected. (Full) closed loop which is made by providing a sensor to perform.

  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 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. The liquid discharged from the head side chamber 39h by the retreat of the piston 41 is returned to the rod side chamber 39r through the head side valve 59 opened by introduction of pilot pressure. 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 rotary injection motor 27, the pressure-increasing motor 29, and the integrated transmission mechanism that transmits the driving force of the injection motor 27 and the pressure-increasing motor 29 to the plunger 23. 31. The integrated transmission mechanism 31 accommodates a piston 41 fixed to the plunger 23 behind the plunger 23 and a piston 41 so as to be slidable, and a head side chamber 39h filled with liquid on the rear side of the piston 41. A cylinder member 39 having an internal pressure, a screw mechanism 69 for injection that converts the rotation of the injection motor 27 into a linear motion and transmits the linear motion to the piston 41, and a pressure increasing member. And a pressurizing member 47 that is driven by the electric motor 29 without using a fluid pressure device and pressurizes the liquid in the head side chamber 39h.

  Therefore, for example, when the plunger 23 is driven by the injection motor 27, the pressure increase motor 29 is substantially separated from the plunger 23 by allowing the piston 41 and the pressure member 47 to be separated. The plunger 23 can be driven. 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. In addition, for example, the liquid in the rod side chamber 39r and / or the head side chamber 39h 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, since the driving force is transmitted from the injection motor 27 to the plunger 23 by the injection screw mechanism 69, for example, it is easy to transmit a relatively large driving force. Since the injection screw mechanism 69 is arranged in parallel to the cylinder mechanism 33, for example, the total length of the injection drive unit 25 including the cylinder mechanism 33 and the injection screw mechanism 69 is the conventional hydraulic injection drive unit (hydraulic pressure). It is close to the injection drive unit including the cylinder), and the installation of the injection device 9 in the factory is facilitated.

  In the present embodiment, the pressure-increasing motor 29 is a rotary type, and the integrated transmission mechanism 31 converts the rotation of the pressure-increasing motor 29 into a linear motion and transmits it to the pressurizing member 47. In comparison, a pressure increasing screw mechanism 83 having a large diameter and a small lead is further provided.

  Accordingly, since the driving force is transmitted from the pressure-increasing electric motor 29 to the pressure member 47 by a screw mechanism, for example, a relatively large driving force can be easily transmitted. Combined with the fact that the screw mechanism is also used to transmit the driving force of the injection motor 27, the injection device 9 as a whole can easily cope with a large-sized 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.

  Further, in the present embodiment, the integrated transmission mechanism 31 extends from the piston 41 to the outside of the rod side chamber 39r via the rod side chamber 39r, and is connected to the plunger 23 and the piston 41 to the head side chamber 39h. Are further provided with a rear rod 45 extending to the outside of the head side chamber 39h, and a communication channel 55 for communicating the rod side chamber 39r and the head side chamber 39h. The pressing member 47 is disposed behind the piston 41. The pressure-increasing screw mechanism 83 has a screw shaft 87 extending rearward from the pressure member 47 and a nut 85 that is screwed into the screw shaft 87 and rotated by the pressure-increasing electric motor 29. The pressing member 47 and the screw shaft 87 are formed with holes 47h and 87h through which the rear rod 45 is inserted.

  Therefore, for example, the liquid can be supplied and discharged between the rod side chamber 39r and the head side chamber 39h, and the excess or deficiency of the liquid generated during the supply and discharge can be reduced by the rear rod 45. Since the rear rod 45 is inserted through the pressure member 47 and the screw shaft 87, for example, they are arranged concentrically, and the size can be reduced.

  In the present embodiment, the integrated transmission mechanism 31 includes an accumulator 57 that communicates with the rod side chamber 39r.

  Therefore, for example, the pressure fluctuation generated in the rod side chamber 39r when the plunger 23 is stopped can be released to the accumulator 57, and the surge pressure can be suppressed. That is, the cylinder mechanism 33 for switching the electric motor used for driving the plunger 23 can be effectively used. 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 flow control valve 61 which can control the flow volume of the liquid discharged | emitted from the rod side chamber 39r.

  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 rod side chamber 39r, thereby suppressing the surge pressure. That is, the cylinder mechanism 33 for switching the electric motor used for driving the plunger 23 can be effectively used.

Second Embodiment
FIG. 4 is a view similar to FIG. 2 showing the configuration of the injection device 209 (injection drive unit 225, integrated transmission mechanism 231) according to the second embodiment.

  The configuration of the injection device 209 of the present embodiment is different from the configuration of the injection device 9 of the first embodiment in that the rear rod 45 is not provided. Accordingly, in this embodiment, a hole through which the rear rod 45 is inserted is not formed in the pressure member 247 of the cylinder mechanism 233. Similarly, in the pressure-increasing screw mechanism 283 of the pressure-increasing transmission mechanism 237 of this embodiment, a hole through which the rear rod 45 is inserted is not formed in the screw shaft 287. For other configurations, the present embodiment may be substantially the same as the first embodiment.

  Note that the diameter of the screw shaft 287 of the pressure increasing screw mechanism 283 and the inner diameter of the nut 285 correspond to the diameter of the screw shaft 87 of the first embodiment corresponding to the fact that the hole through which the rear rod 45 is inserted is not formed. And the inner diameter of the nut 85 can be made smaller, and FIG. 4 illustrates such a mode. However, also in this embodiment, the screw shaft 287 of the pressure increasing screw mechanism 283 preferably has a smaller lead and a larger diameter than the screw shaft 73 of the injection screw mechanism 69.

  The operation of the injection device 209 may be substantially the same as the operation of the injection device 9 of the first embodiment. However, when the pressure of the accumulator 57 is applied to the rod side chamber 39r and the head side chamber 39h, the area (pressure receiving area) where the liquid pressure acts on the piston 41 in the head side chamber 39h is greater than the pressure receiving area of the piston 41 in the rod side chamber 39r. Is larger, the piston 41 moves forward. Therefore, for example, before the start of low-speed injection, the control device 13 fully closes the flow rate control valve 61, prohibits the discharge of liquid from the rod side chamber 39r, and restricts the forward movement of the piston 41.

  As described above, also in the present embodiment, as in the first embodiment, the injection device 209 includes the injection motor 27, the pressure-increasing motor 29, and the integrated transmission mechanism 231 that transmits these driving forces to the plunger 23. In the integrated transmission mechanism 231, the driving force of the injection motor 27 is transmitted to the piston 41 via the injection screw mechanism 69 arranged in parallel with the cylinder mechanism 233, and the driving force of the pressure-increasing motor 29 is the fluid pressure device. It is transmitted to the pressure member 47 without going through.

  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. Further, for example, a relatively large driving force can be transmitted to the plunger 23 with a small size by the injection screw mechanism 69 parallel to the cylinder mechanism 233.

<Third Embodiment>
FIG. 5 is a view similar to FIG. 2 showing the configuration of the injection device 309 (injection drive unit 325) according to the third embodiment. However, FIG. 5 is basically a view from the side. The arrangement and the like of the hydraulic system are for convenience of illustration, and are not limited to this.

  In the first and second embodiments, the flow rate of the liquid discharged from the rod side chamber 39r is controlled by the flow rate control valve 61 immediately before the plunger 23 stops. In contrast, in the present embodiment, the flow rate control valve 61 is not provided, and the flow rate is controlled by other means, which is different from the first and second embodiments. In addition, although there is a difference between the present embodiment and the first and second embodiments, configurations according to differences other than the flow control valve 61 may be replaced with each other between these embodiments. .

(Overall configuration of injection drive unit)
First, the configuration of the injection device 309 of this embodiment is basically the same as that of the first and second embodiments, but is different in details (as described above, can be replaced with other embodiments) ).

  Also in the third embodiment, as in the first and second embodiments, the injection device 309 (injection drive unit 325) is an integration that transmits the injection motor 27, the pressure-increasing motor 29, and these driving forces to the plunger 23. The integrated transmission mechanism 331 includes a cylinder mechanism 333, an injection transmission mechanism 335, and a pressure increase transmission mechanism 337.

  As in the other embodiments, the cylinder mechanism 333 applies the liquid in the cylinder member 339, the piston 341 housed in the cylinder member 339, the front rod 43 extending from the piston 341 and connected to the plunger 23, and the head side chamber 339h. A pressurizing member 347 is provided. In the illustrated example, the cylinder mechanism 333 does not have the rear rod 45 as in the second embodiment.

  The pressure member 347 is provided with an auxiliary rod 348 that extends forward from the pressure member 347 and can come into contact with the piston 341. The auxiliary rod 348 contributes to the regulation of the proximity of the piston 341 and the pressing member 347 beyond a certain level, like the stopper 45s of the first embodiment. Although the pressure member 347 is shown thinner than the pressure members of other embodiments, the thickness of the pressure member 347 may be set as appropriate.

  The injection transmission mechanism 335 is the same as the injection transmission mechanism 35 of the first embodiment except that the guide shaft 75 is not provided between the connecting plate 77 and the screw shaft 73. As a result, the position of the injection motor 27 is more forward than in the first embodiment.

  The pressure-increasing transmission mechanism 337 is the same as the pressure-increasing transmission mechanism 237 of the second embodiment, except that a rotation preventing mechanism 388 that restricts the rotation of the screw shaft 287 is provided. The rotation preventing mechanism 388 includes, for example, a screw side member 388a fixed to the rear end of the screw shaft 287 and a cylinder side member 388b fixed to the rear end of the cylinder member 339. The screw side member 388a and the cylinder member 388b are allowed to move relative to each other in the axial direction parallel to the screw shaft 387, and are restricted from moving relative to each other in the direction perpendicular to the axial direction.

  The position sensor 97 is arranged so as to constitute a linear encoder and a scale unit (not shown) provided on the front rod 43 in response to the fact that the guide shaft 75 is not provided.

  Similar to the liquid control unit 53 of the first embodiment, the liquid control unit 353 that controls the flow of liquid related to the cylinder mechanism 333 includes a communication channel 55, an accumulator 57, and a head-side valve 359.

  Similarly to the first embodiment, the head-side valve 359 can allow bidirectional flow between the rod-side chamber 339r and the head-side chamber 339h, and at least flows from the head-side chamber 339h to the rod-side chamber 339r (in another aspect, the head-side valve 359). The discharge of the liquid from the side chamber 339h can be prohibited. However, in FIG. 5, a non-leak switching valve controlled by electromagnetic force is illustrated as the head side valve 359 instead of the pilot check valve.

(Configuration related to flow control)
Next, a difference from the first and second embodiments (a configuration replacing the flow control valve 61) will be described. In addition, the structure replaced with the flow control valve 61 of this embodiment and the flow control valve 61 may be provided side by side.

  The cylinder member 339 has, on its inner surface, a sliding portion 339e where the piston 341 slides, a port 339k for connecting the rod side chamber 339r and the outside of the cylinder member 339, and between the sliding portion 339e and the port 339k. And a cushion portion 339f having an inner diameter smaller than that of the sliding portion 339e. From another viewpoint, the sliding portion 339e is a portion whose inner diameter is constant in the axial direction.

  The flow path cross-sectional area of the gap between the cushion portion 339f and the front rod 43 (the cross-sectional area perpendicular to the front rod 43) is the cross-sectional area of the port 339k (for example, the cross-sectional area from the inner surface to the outer surface of the cylinder member 339). Larger than the smallest one). The cushion part 339f may have a part that gradually decreases in diameter from the sliding part 339e side to the port 339k side in a part connected to the sliding part 339e. The portion that gradually decreases in diameter may be curved or stepped.

  On the other hand, the piston 341 has a main body 341a that slides in the cylinder member 339, and a front end 341b that is located at the front end of the main body 341a and has a smaller diameter than the main body 341a. The distal end portion 341b may have a portion that gradually decreases in diameter from the main body portion 341a side toward the front at the distal end or the like. The portion that gradually decreases in diameter may be curved or stepped.

  When the piston 341 moves forward in the cylinder member 339, the distal end portion 341b is inserted into the cushion portion 339f. At this time, the flow path cross-sectional area (for example, the smallest of the cross-sectional areas of the flow path from the sliding part 339e to the port 339k) of the gap between the cushion part 339f and the tip part 341b is smaller than the flow path cross-sectional area of the port 339k. Is also small. Therefore, the flow rate of the liquid flowing into the port 339k from the rod side chamber 339r is limited by the cushion portion 339f and the tip portion 341b. As a result, for example, the inertial force of the plunger 23 or the like is reduced immediately before the plunger 23 stops, and the surge pressure is suppressed.

  When the insertion of the distal end portion 341b into the cushion portion 339f is started, the gap (flow passage cross-sectional area) between the two gradually decreases. As a result, the valve gradually closes. The rate of change of the flow cross-sectional area can be adjusted by forming a portion that gradually decreases in diameter at the distal end portion 341b and / or the cushion portion 339f.

  When the plunger 23 stops, it is preferable that the gap between the tip 341b and the cushion 339f is not completely closed. This is because the pressure fluctuation is released to the accumulator 57. However, the gap may be closed. The piston 341 is stopped by being filled with molten metal before reaching the forward limit with respect to the cylinder member 339. However, with the piston 341 reaching the forward limit with respect to the cylinder member 339, The gap may be completely closed or may not be closed.

  The operation of the injection device 309 may be substantially the same as the operation of the injection devices of the first and second embodiments except that the control of the flow control valve 61 is omitted. Since the head side valve 359 formed of a non-leak switching valve does not self-close, when the liquid in the head side chamber 339h is pressurized by the pressurizing member 347, the head side valve 359 is closed by control.

  As described above, also in the present embodiment, as in the first and second embodiments, the injection device 309 includes the injection motor 27, the pressure-increasing motor 29, and the integrated transmission mechanism 331 that transmits the driving force thereof to the plunger 23. In the integrated transmission mechanism 331, the driving force of the injection motor 27 is transmitted to the piston 341 via the injection screw mechanism 69 arranged in parallel with the cylinder mechanism 333, and the driving force of the pressure-increasing motor 29 is It is transmitted to the pressurizing member 347 without going through the fluid pressure device.

  Therefore, also in this embodiment, the same effects as those in the first and second embodiments are achieved. For example, the electric motor that drives the plunger 23 can be suitably switched without using a friction clutch. Further, for example, a relatively large driving force can be transmitted to the plunger 23 with a small size by the injection screw mechanism 69 in parallel with the cylinder mechanism 333.

  In the present embodiment, the cylinder member 339 is located between the port 339k and the sliding portion 339e, and has a cushion portion 339f having an inner diameter smaller than that of the sliding portion 339e. The piston 341 is positioned in front of the main body 341a and the main body 341a, and slides on the sliding portion 339e. The piston 341 has a diameter smaller than that of the main body 341a, and is inserted into the cushion 339f. And a tip portion 339b whose cross-sectional area can be made smaller than the cross-sectional area of the port 339k.

  Therefore, for example, the inertial force immediately before stopping the plunger 23 can be controlled (reduced) with a simple configuration and control in which the flow rate control valve 61 is not provided. Further, for example, in addition to not providing the flow rate control valve 61, a non-leak switching valve is used for the head side valve 359, thereby increasing the hermeticity of the hydraulic system and reducing the need for maintenance such as replenishment of liquid. Can be reduced.

<Fourth embodiment>
FIG. 6 is a view similar to FIG. 2 showing the configuration of the injection device 409 (injection drive unit 425) according to the fourth embodiment.

  In the injection screw mechanism 69 of the first to third embodiments, the rotation of the injection motor 27 is transmitted to the nut 71, and the screw shaft 73 is driven in the front-rear direction together with the plunger 23. On the other hand, in the injection screw mechanism 69 of the present embodiment, the rotation of the injection motor 27 is transmitted to the screw shaft 73, and the nut 71 is driven in the front-rear direction together with the plunger 23 in the first to third embodiments. It differs from the form. For other configurations, the present embodiment may be substantially the same as the other embodiments. In the illustrated example, the configuration of the first embodiment is mainly used for configurations other than the above differences, but the configuration of the second or third embodiment may be used.

  The injection screw mechanism 69 is arranged in parallel to the cylinder mechanism 33 as in the other embodiments. The screw shaft 73 is allowed to rotate around the axis and is restricted from moving in the axial direction. The nut 71 is restricted from rotating around the axis and is allowed to move in the axial direction. The nut 71 is fixed to the plunger 23 via a cover 475 and the like which will be described later. Therefore, when the rotation of the injection motor 27 is transmitted to the screw shaft 73, the nut 71 moves along the screw shaft 73, and as a result, the plunger 23 moves in the front-rear direction.

  For example, the screw shaft 73 is allowed to rotate around the axis and the axial movement is restricted by the screw shaft 73 being supported by an appropriate bearing. The rotation of the nut 71 is restricted, for example, by the nut 71 being connected to the front rod 43 via the cover 475 and the connecting plate 77.

  Transmission to the screw shaft 73 of the injection motor 27 is performed by, for example, a winding transmission mechanism as in the other embodiments. However, the pulley / belt mechanism of this embodiment has a pulley 466 fixed to the screw shaft 73 and on which the belt 67 is hung. In the illustrated example, the direction of the injection motor 27 is opposite to that of the first embodiment, but as described in the third embodiment, the difference can be replaced between the embodiments.

  The nut 71 and the connection plate 77 are connected to each other through a rigid cover 475 that is fixed to the nut 71 and accommodates the screw shaft 73 in a hollow shape (for example, a cylindrical shape having a circular cross section). It is preferable that the front end portion of the cover 475 is closed. By providing such a cover 475, it is possible to protect the portion of the screw shaft 73 located on the tip side of the nut 71 from molten metal splashes. Note that the cover 475 preferably also accommodates the nut 71.

  The cover 475 is guided by the bush of the frame 51, for example, like the guide shaft 75 of the first embodiment, and contributes to suppressing unnecessary moment from being transmitted to the plunger 23. In FIG. 6, assuming that only one injection transmission mechanism 435 is provided, the guide shaft 75 that contributes only to the guide (the rear end is free) on the side opposite to the cover 475 with respect to the cylinder mechanism 33. End). However, instead of the guide shaft 75, a cover 475 (injection transmission mechanism 435) may be provided. In this case, the number of injection motors 27 may be one or two, etc., as in the first embodiment.

  Also in the present embodiment, as in the first embodiment, the injection device 409 includes the injection motor 27, the pressure-increasing motor 29, and the integrated transmission mechanism 431 that transmits these driving forces to the plunger 23. In the transmission mechanism 431, the driving force of the injection motor 27 is transmitted to the piston 41 via the injection screw mechanism 69 arranged in parallel with the cylinder mechanism 33, and the driving force of the pressure-increasing motor 29 does not pass through the fluid pressure device. It is transmitted to the pressure member 47.

  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. Further, for example, a relatively large driving force can be transmitted to the plunger 23 with a small size by the injection screw mechanism 69 parallel to the cylinder mechanism 33.

<Modification>
FIG. 7A and FIG. 7B are schematic views each showing a configuration of a modified example. In these drawings, the same reference numerals as those in the first embodiment are used for configurations that are the same as or similar to those in the embodiment. However, the modification may be applied to other embodiments.

  As shown in FIG. 7A, the pressure member 151 is not limited to a piston that slides in the cylinder member 39. For example, a rod having a smaller diameter than the cylinder member 39 (or a hollow member that communicates with the cylinder member 39). A shaped member may be used. Even in such a configuration, pressurization is performed in the direction in which the pressurizing member 151 is advanced or retracted (the direction in which the volume in which the liquid is stored is reduced or expanded) with respect to the head side chamber 39h (or a sealed space communicating with the head side chamber 39h). By applying a driving force to the member 151, it is possible to pressurize or release the pressurization of the head side chamber 39h. Further, since the pressure member 151 has a smaller pressure receiving area (area receiving pressure from the liquid in the forward / backward direction) than the piston-shaped member, the load on the pressure-increasing electric motor 29 can be reduced.

  The pressure member 151 (the pressure-increasing electric motor 29) may contribute to driving the piston 41 forward by contacting the rear end of the piston 41 in low-speed injection or the like. In this case, like the rear rod 45 of the first embodiment, the pressure member 151 contributes to alleviation of excess and deficiency of the liquid in the rod side chamber 39r and the head side chamber 39h.

  As shown in FIG. 7B, the pressurizing member 153 is not arranged coaxially with the piston 41, and may advance and retreat in a direction intersecting (for example, orthogonal to) the moving direction of the piston 41, for example. In this aspect, when the rear rod 45 is provided, the rear rod 45 extends directly from the cylinder member 39 to the outside without penetrating the pressure member 153.

  Further, as shown in FIG. 7B, the pressure member 153 may be advanced and retracted in another cylinder member 155 connected to the cylinder member 39. In the illustrated example, the cylinder member 155 is directly connected to the cylinder member 39, but may be connected to the cylinder member 39 via a flow path. The cylinder member 155 may have a smaller diameter than the cylinder member 39 from the viewpoint of reducing the amount of liquid or reducing the burden on the pressure-increasing electric motor 29.

  As shown in FIG. 7B, the rod side chamber 39r and the accumulator 57 may be connected without providing either the flow rate control valve 61 of the first embodiment or the cushion portion 339f of the third embodiment. Even in this aspect, the accumulator 57 contributes to elimination of excess or deficiency of the liquid, suppression of surge pressure, and the like.

  In addition to the illustrated example, various modifications may be made. For example, the pressure member that is driven in a direction intersecting the moving direction of the piston 41 as shown in FIG. 7B is not configured as a piston, but is a cylinder member as shown in FIG. A rod shape smaller than 155 or a rod shape inserted into the head side chamber 39h from the side surface of the cylinder member 39 may be used. The small diameter cylinder member 155 may be coaxially connected to the cylinder member 39. Further, for example, the pressurizing member has a cylinder shape that covers the rear end portion of the cylinder member 39 so as to be slidable on the outer peripheral surface of the cylinder member 39 and pressurizes the inside of the cylinder member 39 through the rear end opening of the cylinder member 39. There may be.

  In the above embodiments and modifications, the die-casting machine 1 is an example of a molding machine, the injection motor 27 is an example of a first motor, the pressure-increasing motor 29 is an example of a second motor, and integrated transmission The mechanisms 31, 231, 331 and 431 are examples of transmission mechanisms, the plunger 23 is an example of an injection plunger, the injection screw mechanism 69 is an example of a first screw mechanism, and the pressure-increasing screw mechanisms 83 and 283 are Each of them is an example of a second screw mechanism, and the communication channel 55 is an example of a channel.

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

  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. The low-speed injection by the second electric motor may be one in which the piston is driven by the pressurizing member through the liquid in the head side chamber, and as mentioned in the description of the modified example in FIG. The pressure member may be brought into contact with the piston. 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.

  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 pressurizing member may not be provided. Further, when the second electric motor is of a rotary type, the mechanism for converting the rotation into linear motion is not limited to the screw mechanism. For example, a cam mechanism or a link mechanism may be used.

  A rotation transmission mechanism (in the embodiment, a winding transmission mechanism) that transmits the rotation of the first or second motor without converting it into linear motion may not be provided. For example, the output shaft of the electric motor may be fixed coaxially or concentrically to the screw shaft or the nut. The rotation transmission mechanism may be a mechanism other than the winding transmission mechanism such as a gear mechanism.

  In the embodiment, the rod side chamber filled with the liquid is configured before the piston, and the liquid in the rod side chamber is used for reducing the surge pressure. However, the liquid may not be filled before the piston. For example, the rod side chamber is not sealed and may be open to the atmosphere. In this case as well, a small amount of oil that contributes to lubrication between the piston and the cylinder member may be stored in the rod side chamber.

  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 rod side chamber is replenished by, for example, sucking the liquid by the negative pressure in these cylinder chambers. Further, for example, excess liquid may not be generated, and when the liquid is insufficient, a vacuum space may be formed in the head side chamber or the rod side chamber.

  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 apparatus, 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 ... Piston, 47: Pressurizing member, 69: Screw mechanism for injection (first screw mechanism).

Claims (7)

A rotary first electric motor;
A second electric motor;
A transmission mechanism for transmitting the driving force of the first motor and the second motor to the injection plunger;
With
The transmission mechanism is
A piston fixed to the injection plunger behind the injection plunger;
A cylinder member that slidably accommodates the piston, and has a head side chamber filled with liquid on the rear side of the piston;
A first screw mechanism that is arranged in parallel to the cylinder member, converts the rotation of the first electric motor into a linear motion, and transmits the linear motion to the 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;
Having an injection device. The second electric motor is rotary;
The transmission mechanism is
The second screw mechanism having a large diameter and a small lead as compared with the first screw mechanism that converts the rotation of the second electric motor into a linear motion and transmits the linear motion to the pressure member. The injection device described. The second electric motor is rotary;
The cylinder member includes a rod side chamber filled with a liquid on a front side of the piston,
The transmission mechanism is
A second screw mechanism that converts rotation of the second electric motor into linear motion and transmits the linear motion to the pressure member;
A front rod extending from the piston to the outside of the rod side chamber via the rod side chamber, and connected to the injection plunger;
A rear rod extending from the piston to the outside of the head side chamber via the head side chamber;
A flow path communicating the rod side chamber and the head side chamber;
Further comprising
The pressure member is disposed behind the piston;
The second screw mechanism is
A screw shaft extending rearward from the pressure member;
A nut screwed into the screw shaft and rotated by the second electric motor;
Have
The injection device according to claim 1, wherein a hole through which the rear rod is inserted is formed in the pressure member and the screw shaft. The cylinder member includes a rod side chamber filled with a liquid on a front side of the piston,
The injection device according to claim 1, wherein the transmission mechanism includes an accumulator that communicates with the rod side chamber. The cylinder member includes a rod side chamber filled with a liquid on a front side of the piston,
The injection device according to any one of claims 1 to 4, wherein the transmission mechanism includes a flow rate control valve capable of controlling a flow rate of the liquid discharged from the rod side chamber. The cylinder member includes a rod side chamber filled with a liquid on a front side of the piston,
The cylinder member is
A sliding portion in which the inner diameter is constant in the axial direction and the piston slides;
A port opening in the rod side chamber;
A cushion part located between the port and the sliding part and having a smaller inner diameter than the sliding part;
Have
The piston is
A body portion sliding on the sliding portion;
The cross-sectional area of the flow path from the sliding portion to the port in the gap with the cushion portion by insertion into the cushion portion is located on the front side of the main body portion and is smaller in diameter than the main body portion. A tip that can be made smaller,
The injection device according to any one of claims 1 to 5. The injection device according to any one of claims 1 to 6,
A mold clamping device for clamping the mold;
An extrusion device for extruding a molded product from the mold;
A molding machine.

Images