JP2016055307A - Injection unit, and molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection unit capable of lightening the burden on an electric motor.SOLUTION: An injection unit 1 comprises: an injection cylinder device 9 arranged with a cylinder member 29 stationally; a screw mechanism 12 interposed between a plunger 5 and a piston rod 35 of the injection cylinder device 9 and capable of moving them relatively in cross directions; and a nut electric motor 19N for rotating the nut 13 of the screw mechanism 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a molding apparatus (molding machine) and an injection apparatus thereof. The molding apparatus is, for example, a die casting machine or an injection molding machine.

  A so-called hybrid injection device is known in which a plunger that pushes a molding material in a sleeve into a cavity is driven by a combination of a hydraulic device and another driving device (for example, an electric motor).

  For example, the injection device disclosed in Patent Document 1 includes an injection cylinder device connected to a plunger, a ball screw mechanism that can move the injection cylinder device, and an electric motor that drives the ball screw mechanism. This injection device performs low-speed injection by driving an electric motor, and then performs high-speed injection by supplying hydraulic fluid to the injection cylinder device while continuing to drive the electric motor.

  An injection device that can selectively execute the standard injection method and the ultra-low speed injection method is also known (for example, Patent Document 2). The standard injection method includes a low speed injection process and a high speed injection process following the low speed injection process as main processes. The ultra-low speed injection method is a method including an injection process at an injection speed lower than the injection speed of the low speed injection process as a main process. In addition, an injection device is known in which a plunger that pushes a molding material in a sleeve into a cavity is driven only by an electric motor (for example, Patent Documents 3 and 4).

JP 2008-114234 A Japanese Patent Laid-Open No. 05-253661 JP 2008-230192 A JP 2009-012050 A

  Since the injection device of patent document 1 moves an injection cylinder apparatus with an electric motor, the burden of an electric motor is large. As a result, for example, it becomes necessary to specially order a large electric motor, resulting in an increase in cost. In addition, in the injection devices of Patent Documents 3 and 4, since the injection operation is performed only by the electric motor, the load on the electric motor is increased during high-speed injection. As a result, for example, it becomes necessary to specially order a large electric motor, resulting in an increase in cost.

  Accordingly, it is desirable to provide an injection device and a molding device that can reduce the burden on the electric motor.

  An injection device according to an aspect of the present invention includes a plunger that can move back and forth in a sleeve, a cylinder member that is fixedly disposed, a piston that is housed in the cylinder member so as to be slidable in the front-rear direction, and the piston An injection cylinder device having a piston rod fixed to the piston rod, a male screw member and a female screw member interposed between the plunger and the piston rod, and by relative rotation around the axis of the male screw member and the female screw member. A screw mechanism capable of relatively moving the plunger and the piston rod in the front-rear direction; and an electric motor that rotates at least one of the male screw member and the female screw member.

  Preferably, the injection device further includes a rotating member that is not rotatable with respect to the one of the male screw member and the female screw member and is relatively movable in the front-rear direction, and the electric motor is fixedly disposed, The rotation is transmitted to the one of the male screw member and the female screw member by being transmitted to the rotating member.

  Preferably, the rotating member includes a first rotating member that is non-rotatable and relatively movable in the front-rear direction with the one of the male screw member and the female screw member, and a second rotating member, and extends in an annular shape. A flexible elongated member that is hung on the first rotating member and the second rotating member is further provided, and the rotation of the electric motor is sequentially performed on the second rotating member, the elongated member, and the first rotating member. By being transmitted, it is transmitted to the one of the male screw member and the female screw member.

  Preferably, the electric motor includes a first electric motor that rotates one of the male screw member and the female screw member, and a second electric motor that rotates the other of the male screw member and the female screw member.

  Preferably, the first electric motor and the second electric motor are controlled such that the male screw member and the female screw member are rotated in opposite directions to advance the plunger.

  Preferably, the injection device further includes a rotation restricting member that restricts rotation of the other of the male screw member and the female screw member.

  A molding apparatus according to an aspect of the present invention includes the above-described injection device.

  According to the present invention, the burden on the electric motor can be reduced.

The schematic diagram which shows the structure of the principal part of the die-casting machine which concerns on the 1st Embodiment of this invention in the state before an injection start. The schematic diagram which shows the structure of the principal part of the die-casting machine of FIG. 1 in the state of the injection completion of a super-low-speed injection method. The schematic diagram which shows the structure of the principal part of the die-casting machine of FIG. 1 in the state of the injection completion of a standard injection method. Sectional drawing in the IV-IV line of FIG. The figure explaining operation | movement of the injection device of the die-casting machine of FIG. The schematic diagram which shows the structure of the principal part of the die-casting machine concerning the 2nd Embodiment of this invention.

<First Embodiment>
(Configuration of injection device)
FIGS. 1 to 3 are cross-sectional views seen from the side schematically showing the configuration of the main parts of the die casting machine DC1 and the injection apparatus 1 according to the first embodiment of the present invention. FIG. 1 shows a state before the start of injection. FIG. 2 shows the state of injection completion in the ultra-low speed injection method. FIG. 3 shows a state of injection completion in the standard injection method. Note that the completion of injection referred to here is completion of injection in a narrow sense that does not include pressure increase or holding pressure.

  In the following, the left side of FIG. 1 (the direction in which the plunger 5 advances when the molten metal is pushed out into the cavity 105 by the plunger 5) may be referred to as the front, and the right side of FIG.

  For example, the die casting machine DC1 includes a molding material (not shown) that clamps the fixed mold 101 and the movable mold 103, and a molding material in the cavity 105 that is configured by the clamped fixed mold 101 and the movable mold 103. An injection device 1 for injecting and filling molten metal (a molten metal material) as (material), and an unillustrated extrusion device for extruding a molded die-cast product (molded product) from the fixed mold 101 or the moving mold 103; And a control device 111 for controlling these devices. Note that the control device 111 may be regarded as constituting a part of each device.

  The injection device 1 includes a sleeve 3 that communicates with the cavity 105, a plunger 5 that pushes the molten metal in the sleeve 3 into the cavity 105, an electric drive unit 7 that drives the plunger 5, an injection cylinder device 9 that also drives the plunger 5, And a hydraulic device 11 for supplying hydraulic fluid to the injection cylinder device 9.

  The sleeve 3 is provided so as to be inserted through a fixed die plate (not shown) that holds the fixed mold 101, for example. The sleeve 3 may be inserted through the fixed mold 101. The plunger 5 includes a plunger tip 5a that can slide the sleeve 3 in the front-rear direction, and a plunger rod 5b that is fixed to the plunger tip 5a. In the present application, “fixed” includes not only the case where the two members are connected but also the case where the two members are formed integrally.

  When the molten metal is supplied into the sleeve 3 from the hot water supply port 3 a formed in the sleeve 3, the plunger tip 5 a slides (moves forward) toward the cavity 105 in the sleeve 3, so that the molten metal is contained in the cavity 105. Injected and filled.

  The electric drive unit 7 has a screw mechanism 12 interposed between the plunger 5 and the injection cylinder device 9. Specifically, for example, the screw mechanism 12 includes a nut 13 connected to the plunger 5 and a bolt 15 screwed to the nut 13. As will be described later, the movement of the bolt 15 in the front-rear direction is restricted by the injection cylinder device 9.

  Therefore, as indicated by arrows in FIG. 2, the nut 13 and the bolt 15 rotate in opposite directions, and as a result, when the relative rotation occurs, the nut 13 moves forward. Further, each of the nut 13 and the bolt 15 rotates in a direction opposite to that when the nut 13 moves forward, and when the nut 13 and the bolt 15 rotate relative to each other in a direction opposite to that when the nut 13 moves forward, the nut 13 moves backward.

  The nut 13 is formed, for example, in a generally cylindrical shape with the rear opened, and an internal thread is formed on the inner peripheral surface thereof. The nut 13 and the plunger 5 cannot be moved relative to each other in the front-rear direction. For example, a shaft portion that protrudes forward is formed at the front end of the nut 13, and the shaft portion is connected to the rear end of the plunger rod 5 b by a coupling 17.

  The nut 13 and the plunger rod 5b are preferably rotatable relative to each other around the axis. In this case, for example, it is possible to suppress an increase in the torque necessary for the rotational drive of the nut 13 due to the moment of inertia of the plunger 5 and the frictional resistance between the plunger 5 and the sleeve 3. A bearing may be interposed between the nut 13 and the plunger 5.

  For example, the bolt 15 is formed in a substantially cylindrical shape with the rear opened, and a male screw is formed on the front side portion of the outer peripheral surface thereof. The bolt 15 may be solid. However, since the bolt 15 is cylindrical, the weight of the bolt 15 can be reduced. The connection between the bolt 15 and the injection cylinder device 9 will be described later.

  The screw mechanism 12 may be a ball screw mechanism or a sliding screw mechanism. Preferably, the screw mechanism 12 is constituted by a sliding screw mechanism. In the case of a sliding screw mechanism, for example, when the nut 13 receives a backward force, the nut 13 is prevented from moving backward with respect to the bolt 15 while causing relative rotation between the nut 13 and the bolt 15. The

  The lead angle of the screw mechanism 12 may be set as appropriate. When the lead angle is reduced, the backward movement of the nut 13 as described above is suppressed, but it is difficult to increase the forward speed of the nut 13. Therefore, for example, the lead angle is preferably maximized within a range in which the nut 13 is retracted by the maximum force assumed by the nut 13 from the plunger 5 and is not retracted.

  The electric drive unit 7 includes a nut motor 19N and a nut transmission mechanism 21N that transmits the rotation of the nut motor 19N to the nut 13 in order to rotate the nut 13. Further, the electric drive unit 7 includes a bolt motor 19B and a bolt transmission mechanism 21B that transmits the rotation of the bolt motor 19B to the bolt 15 in order to rotate the bolt 15.

  Hereinafter, the nut motor 19N and the bolt motor 19B may be simply referred to as the motor 19 without being distinguished from each other. Further, the nut transmission mechanism 21N and the bolt transmission mechanism 21B may be simply referred to as the transmission mechanism 21 without being distinguished from each other. Further, in the drawings, “N” is attached to the reference numeral of the member included in the nut transmission mechanism 21N, “B” is attached to the reference numeral of the member included in the bolt transmission mechanism 21B, and “N” “B” is described in the following description. ] May be omitted.

  The electric motor 19 is a rotary type. The electric motor 19 may be a direct current motor or an alternating current motor, and may be an induction motor or a synchronous motor. The electric motor 19 is, for example, a servo motor that follows an input command in combination with an encoder (not shown) and a servo driver (not shown).

  In the description of the operation to be described later, when the electric motor 19 is stopped, the electric motor 19 may be in a torque-free state, may be controlled to stop at a certain position, and includes a brake. And a brake may be used. An appropriate stopping method may be selected according to the situation where the electric motor 19 is stopped.

  The electric motor 19 is fixedly arranged. For example, the die casting machine DC1 has a base 113 to which a fixed die plate (not shown) or the like is fixed, and the main body (stator) of the electric motor 19 is fixed to the base 113.

  The nut transmission mechanism 21N includes, for example, an input pulley 23N fixed to the output shaft of the nut electric motor 19N, an output pulley 27N attached so as not to rotate relative to the nut 13, and the input pulley 23N and the output pulley 27N. And a belt 25N hung on the belt.

  Similarly, the bolt transmission mechanism 21B includes, for example, an input pulley 23B fixed to the output shaft of the bolt motor 19B, an output pulley 27B attached so as not to rotate relative to the bolt 15, an input pulley 23B, A belt 25B hung on the output pulley 27B.

  4 is a cross-sectional view taken along line IV-IV in FIG.

  The belt 25N is, for example, a toothed belt. The output pulley 27N has a plurality of teeth corresponding to the plurality of teeth of the belt 25N. Although not particularly illustrated, the input pulley 23N also has a plurality of teeth corresponding to the plurality of teeth of the belt 25N. Although not particularly shown, the belt 25B, the output pulley 27B, and the input pulley 23B also have a plurality of teeth.

  The output pulley 27N has one or more grooves 27s extending in the front-rear direction on the inner peripheral surface. On the other hand, on the outer peripheral surface of the nut 13, a ridge 13s extending in the front-rear direction and fitted in the groove 27s is formed. As a result, the output pulley 27N and the nut 13 cannot be relatively rotated around the axis, and can be relatively moved in the axial direction (front-rear direction).

  Therefore, as shown in FIG. 2, when the nut motor 19N is driven and the rotation is transmitted to the output pulley 27N via the input pulley 23N and the belt 25N, the nut 13 rotates together with the output pulley 27N. On the other hand, the nut 13 moves forward and backward with respect to the output pulley 27N by the driving force in the front-rear direction accompanying the relative rotation with the bolt 15.

  Similar to the output pulley 27N and the nut 13, the output pulley 27B has a groove 27s extending in the front-rear direction on its inner peripheral surface, and the bolt 15 extends in the front-rear direction on its outer peripheral surface and is fitted in the groove 27s. 15 s (FIGS. 1 to 3).

  Therefore, as shown in FIG. 2, when the bolt motor 19B is driven and the rotation is transmitted to the output pulley 27B via the input pulley 23B and the belt 25B, the bolt 15 rotates together with the output pulley 27B. Further, as shown in FIG. 3, the bolt 15 moves forward and backward with respect to the output pulley 27 </ b> B by the driving force of the injection cylinder device 9. At this time, the nut 13 also moves forward and backward with respect to the output pulley 27N.

  Although not particularly illustrated, a member (for example, a bearing) that restricts the movement of the output pulley 27 in the front-rear direction may be appropriately provided.

  Returning to FIG. 1 to FIG. 3, the injection cylinder device 9 is constituted by, for example, a direct connection type pressure increasing cylinder. That is, the injection cylinder device 9 includes a cylinder member 29, an injection piston 31 and a pressure increasing piston 33 that can slide inside the cylinder member 29, and a piston rod 35 that extends forward (from the plunger 5 side) from the injection piston 31. Have.

  The cylinder member 29 has an injection cylinder part 29a and a pressure increasing cylinder part 29b which is located behind the injection cylinder part 29a and has an inner diameter larger than that of the injection cylinder part 29a. The injection piston 31 is slidable on the injection cylinder part 29a and divides the inside of the injection cylinder part 29a into a front rod side chamber 29r and a head side chamber 29h on the opposite side. The pressure increasing piston 33 has a small diameter portion 33a that can slide the injection cylinder portion 29a and a large diameter portion 33b that can slide the pressure increasing cylinder portion 29b. The large diameter portion 33b divides the inside of the pressure increasing cylinder portion 29b into a front front chamber 29f and a rear rear chamber 29e. The tip of the piston rod 35 extends from the cylinder member 29 (rod side chamber 29r).

  The injection piston 31 can move forward by supplying hydraulic fluid to the head side chamber 29h, and the injection piston 31 can move backward by supplying hydraulic fluid to the rod side chamber 29r. Further, when the hydraulic fluid outflow from the head side chamber 29h is restricted, the hydraulic pressure is applied to the rear side chamber 29e, and the front side chamber 29f is set to the tank pressure, according to the difference in pressure receiving area before and after the pressure increasing piston 33. The hydraulic fluid in the head side chamber 29h is increased.

  The cylinder member 29 is fixed to a fixed die plate (not shown) or the like. For example, the die casting machine DC1 includes the above-described base 113 and a support frame 115 fixed to the base 113, and the cylinder member 29 is fixed to the support frame 115. On the other hand, the piston rod 35 is connected to the bolt 15 at its tip. Accordingly, when the injection piston 31 moves back and forth with respect to the cylinder member 29 by supplying hydraulic fluid as described above, the bolt 15, the nut 13 and the plunger 5 move back and forth.

  If the plunger 5 receives a resistance force from the molten metal or the like when the plunger 5 is moved forward, a force for moving the nut 13 backward relative to the bolt 15 is applied to the nut 13. The relative retreat of the nut 13 with respect to the bolt 15 may be appropriately suppressed. For example, the nut 13 may be restrained by being positioned at the backward limit with respect to the bolt 15 (for example, the rear end of the female screw of the nut 13 reaches the rear end of the male screw of the bolt 15). Or may be suppressed by suppressing the rotation of the nut 13 and the bolt 15 by the driving force or brake of the electric motor 19.

  The bolt 15 and the piston rod 35 are not movable relative to each other in the front-rear direction. For example, a flange is provided at the tip of the piston rod 35, and the bolt 15 includes members that are fixed to each other so as to sandwich the flange in the front-rear direction (the dividing line is omitted in the figure).

  The bolt 15 and the piston rod 35 are preferably rotatable relative to each other around the axis. In this case, for example, it is possible to suppress an increase in torque necessary for rotational driving of the bolt 15 by the moment of inertia of the piston rod 35 and the injection piston 31 and the frictional resistance between the injection piston 31 and the cylinder member 29. A bearing may be interposed between the bolt 15 and the piston rod 35.

  The hydraulic device 11 includes, for example, a tank 37 that stores hydraulic fluid, a pump 39 that delivers hydraulic fluid from the tank 37, a pump motor 41 that drives the pump 39, and an accumulator 43 that supplies accumulated hydraulic fluid. And a hydraulic circuit 45 for connecting these elements and the injection cylinder device 9 to each other.

  The tank 37 is an open tank, for example, and holds hydraulic fluid under atmospheric pressure. For example, the tank 37 receives hydraulic fluid from the injection cylinder device 9 via the hydraulic circuit 45 and the like, and supplies hydraulic fluid to the accumulator 43 via the pump 39 and the hydraulic circuit 45.

  The pump 39 may be a rotary pump that discharges hydraulic fluid by rotation of a rotor such as a gear pump or a vane pump, or discharges hydraulic fluid by reciprocation of a piston such as an axial plunger pump or a radial plunger pump. A plunger pump may be used. The pump 39 may be configured by a constant displacement pump in which the discharge amount in one cycle of movement of the rotor or piston is fixed, or may be configured by a variable displacement pump in which the discharge amount is variable. The pump 39 is sufficient if it can discharge the hydraulic fluid in one direction, but the structure may be the same as that of the bidirectional (two-way) pump.

  The pump motor 41 is, for example, a rotary motor. The pump motor 41 may be a DC motor or an AC motor, or may be an induction motor or a synchronous motor. The pump motor 41 may function as a constant speed motor provided in an open loop, or may function as a servo motor provided in a closed loop. As in the case of the electric motor 19, when the pump electric motor 41 is stopped, an appropriate stopping method may be selected depending on the situation in which the pump electric motor 41 is stopped.

  The accumulator 43 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. For example, the accumulator 43 is a gas pressure type, cylinder type or prada type accumulator, and pressure is accumulated by compressing a gas (for example, air or nitrogen) held in the accumulator 43. The accumulated hydraulic fluid is supplied to the injection cylinder device 9 via the hydraulic circuit 45.

  The hydraulic circuit 45 includes a plurality of flow paths that connect the injection cylinder device 9, the tank 37, the pump 39, and the accumulator 43, and a plurality of valves that control the flow of hydraulic fluid in the plurality of flow paths. Yes. The plurality of flow paths are constituted by, for example, a steel pipe, a flexible hose, or a metal block. The plurality of valves are, for example, non-pilot type or pilot type check valves, switching valves, and servo valves that perform flow rate control.

  The control device 111 includes, for example, a CPU, a ROM, a RAM, an external storage device, an input circuit, and an output circuit, although not particularly illustrated. The control device 111 outputs a control signal for controlling each unit based on various input signals that have been input.

  The signal is input to the control device 111, for example, an input device (not shown) that accepts a user input operation, an encoder (not shown) of the electric motor 19, an encoder (not shown) of the pump motor 41, and the position of the plunger 5 are detected. The position sensor 47 is a pressure sensor (not shown) that detects the pressure of the working fluid at an appropriate position in the hydraulic system.

  The control device 111 outputs a signal, for example, a display (not shown) that displays information to the user, a driver (not shown) that supplies power to the motor 19, and a driver (not shown) that supplies power to the pump motor 41. The hydraulic circuit 45.

  For example, the position sensor 47 constitutes a linear encoder together with a scale unit (not shown). For example, the position sensor 47 is fixedly provided behind the sleeve 3, and the scale portion is fixedly provided with respect to the plunger 5 and extends in the front-rear direction. The position sensor 47 detects the position of the plunger 5 by detecting the position of the scale portion that moves as the plunger 5 moves. The position sensor 47 or the control device 111 can detect the speed by differentiating the detected position.

  The pressure sensor is provided at an appropriate position in the hydraulic system. For example, although not particularly illustrated, a pressure sensor for detecting the pressure of the head side chamber 29h and a pressure sensor for detecting the pressure of the rod side chamber 29r are provided, and the control device 111 determines whether the plunger 5 The pressure applied to the molten metal can be specified. Further, for example, although not particularly shown, a pressure sensor for detecting the pressure of the accumulator 43 is provided, and the control device 111 can determine the completion of filling of the accumulator 43 based on the detected value.

(Operation of injection device)
FIG. 5 is a diagram for explaining the operation of the injection apparatus 1. In FIG. 5, the horizontal axis represents time. In the uppermost graph, the vertical axis indicates the injection speed (the speed of the plunger 5). In the lower graph, the vertical axis indicates the relative speed of the nut 13 with respect to the bolt 15 of the electric drive unit. In the lower graph, the vertical axis indicates the rotational speed of the pump 39. In the lower graph, the vertical axis indicates the operation of the accumulator 43.

  The injection apparatus 1 can selectively execute a standard injection method indicated by a dotted line and an ultra-low speed injection method indicated by a solid line. In addition, the dashed-dotted line and the dashed-two dotted line have shown the modification mentioned later.

The standard injection method is an injection method that is generally widely used, and includes a low-speed injection process (t0 to t2) and a high-speed injection process (t2 to t3). That is, in the initial stage of injection, the plunger 5 is advanced at a relatively low speed V _L to prevent the molten air from being caught, and then the molten metal is filled without delaying the solidification of the molten metal. viewpoint plunger 5 is advanced at a relatively fast speed V _H from. Thereafter, although not particularly shown, in order to eliminate sink marks in the molded product, the molten metal in the cavity is increased and held by the force in the direction in which the plunger 5 moves forward.

The speed V _L is set according to various conditions such as the diameter of the sleeve 3 and the amount of hot water per shot, and is, for example, less than 1.0 m / s, and more specifically, for example, 0.2 m / s. s to 0.5 m / s. Although the speed _{VH is} also set according to various conditions, it is, for example, 1 m / s or more, and more specifically, for example, 2 m / s or more and 10 m / s or less.

The ultra-low speed injection method is an injection method used in the manufacture of ultra-precision parts and the like, for example, lower than the speed V _L of the low speed injection process so that the molten metal is surely filled into the fine irregularities of the cavity 105. It contains low-speed injection step (tl to) to advance the plunger 5 at a velocity _{V S.} Prior to the low speed injection process, in order to prevent the molten metal from solidifying before reaching the cavity 105, an initial injection process in which the plunger 5 is advanced at a speed close to the speed V _L of the low speed injection process ( t0 to t1) may be performed.

The speed V _S is, for example, less than 0.2 m / s, and more specifically, for example, 0.01 m / s or more and less than 0.05 m / s. Moreover, the speed | rate of an initial stage injection process is 0.05 m / s or more and 0.25 m / s or less, for example.

  It should be noted that the shape of the cavity 105, the amount of hot water, and the like are different between the graph of change with time of the standard injection method and the graph of change with time of the ultra-low speed injection method shown in FIG. In FIG. 5, the start time t2 of the high-speed injection process comes after the start time t1 of the ultra-low-speed injection process, but this is not necessarily the case.

  The control device 111 receives, for example, a setting for executing a standard injection method or an ultra-low speed injection method via an input device (not shown), and based on the setting, which of the standard injection method and the ultra-low speed injection method is selected. The operation of each unit is controlled to execute this.

(Operation of each part in the standard injection method)
In the standard injection method, for example, the plunger 5 is basically driven only by the driving force of the injection cylinder device 9 and not by the driving force of the electric drive unit 7. That is, the electric motor 19 is stopped, the working fluid is supplied to the injection cylinder device 9, and the plunger 5 is driven. The supply of the hydraulic fluid to the injection cylinder device 9 may be performed in the same manner as a known hydraulic injection device having only the injection cylinder device 9 as a drive source for driving the plunger 5. For example, it is as follows.

(Low speed injection process: t0 to t2)
Before the start of the low-speed injection process, the injection device 1 is in the state shown in FIG. 1, for example. That is, the nut 13 is located at the retreat limit with respect to the bolt 15, the injection piston 31 is located at the retreat limit with respect to the cylinder member 29, and the pressure increasing piston 33 is retreated with respect to the cylinder member 29. Is located. The electric motor 19 and the pump electric motor 41 are stopped, and the charging of the accumulator 43 is completed. Each cylinder chamber has a tank pressure, for example.

When a predetermined injection start condition is satisfied, such as completion of mold clamping by a mold clamping device (not shown) and completion of supply of molten metal to the sleeve 3 by a water heater (not shown), the control device 111 causes the liquid from the accumulator 43 to The hydraulic fluid is supplied to the head side chamber 29h via the pressure circuit 45. As a result, the injection piston 31 moves forward, and as a result, the plunger 5 moves forward at the speed _VL .

  At this time, the hydraulic fluid discharged from the rod side chamber 29r may be discharged to the tank 37 via the hydraulic circuit 45 or to the head side chamber 29h via the hydraulic circuit 45 (runaround circuit not shown). It may be refluxed. Further, as already described, the bolt 15 and the nut 13 interposed between the piston rod 35 and the plunger 5 advance while moving relative to the output pulley 27 in the front-rear direction.

  The speed control of the plunger 5 is performed by, for example, the opening of a servo valve (not shown) constituting the meter-in circuit in the hydraulic circuit 45 based on the detection result of the position sensor 47 and / or the hydraulic pressure. This is realized by feedback-controlling the opening degree of a servo valve (not shown) constituting the meter-out circuit in the circuit 45.

(High-speed injection process: t2 to t3)
When the high-speed injection start condition is satisfied, for example, when the position of the plunger 5 detected by the position sensor 47 reaches a predetermined switching position, the control device 111 increases the amount of hydraulic fluid in the accumulator 43 more than in the low-speed injection. A valve (not shown) of the hydraulic circuit 45 is controlled so as to be supplied to 29h. Thus, the injection piston 31 moves forward at a relatively high speed, thus, the plunger 5 is advanced at a velocity V _H.

  At this time, the hydraulic fluid discharged from the rod side chamber 29r may be discharged to the tank 37 or returned to the head side chamber 29h, as in the low speed injection process. Further, the bolt 15 and the nut 13 move forward relative to the output pulley 27 in the front-rear direction, similarly to the low-speed injection process.

  The speed control of the plunger 5 is performed by, for example, the opening of a servo valve (not shown) constituting the meter-in circuit in the hydraulic circuit 45 based on the detection result of the position sensor 47 and / or the hydraulic pressure. This is realized by feedback-controlling the opening degree of a servo valve (not shown) constituting the meter-out circuit in the circuit 45.

(After high-speed injection process: t2)
When the molten metal is filled into the cavity 105 to some extent, the plunger 5 receives a reaction force from the filled molten metal and decelerates, while the injection pressure rapidly increases (t2 to t3). The operation of each part is the same as that during high-speed injection. However, in order to alleviate the impact at the time of filling, appropriate deceleration control may be performed by a meter-out circuit or the like when a predetermined deceleration start condition is satisfied, such as the plunger 5 reaching a predetermined deceleration position.

  Next, although not particularly illustrated, the control device 111 sets the rod side chamber 29r and the front side chamber 29f to the tank pressure, prohibits the discharge of the hydraulic fluid from the head side chamber 29h, and applies the hydraulic pressure of the accumulator 43 to the rear side chamber 29e. Thus, the hydraulic circuit 45 is controlled. Thereby, pressure increase and holding pressure are performed.

  After that, when the molten metal solidifies, the control device 111 performs mold opening by a mold clamping device (not shown), and pushes out a molded product from the mold by an extrusion device (not shown). At this time, the injection device 1 may perform an operation of pushing a biscuit. The said operation | movement is implement | achieved by the driving force of the injection cylinder apparatus 9, for example.

  Further, the control device 111 controls the hydraulic circuit 45 so as to return the injection piston 31 (plunger 5) and the pressure increasing piston 33 to the initial positions. This control may be the same as the control in a known hydraulic injection device.

(Operation of each part in the ultra-low speed injection method)
In the ultra-low speed injection method, for example, the plunger 5 is basically driven only by the driving force of the electric drive unit 7 and not by the driving force of the injection cylinder device 9. That is, the hydraulic fluid is not supplied to the injection cylinder device 9, the electric motor 19 is rotated, and the plunger 5 is driven. For example, it is as follows.

(Initial injection process: t0 to t1)
Before the start of the initial injection process, the injection device 1 is, for example, in the same state as before the low-speed injection process described above. When a predetermined injection start condition is satisfied, the control device 111 drives the nut motor 19N and the bolt motor 19B. The rotation direction of the two electric motors 19 is a direction in which the nut 13 and the bolt 15 rotate in directions opposite to each other and the nut 13 moves forward. Thereby, the plunger 5 moves forward at a speed relatively close to the speed _VL .

(Ultra-low speed injection process: t1)
When the start condition of the ultra-low speed injection is satisfied, such as the position of the plunger 5 detected by the position sensor 47 reaches a predetermined switching position, the control device 111 rotates the rotational speed of the nut motor 19N and / or the bolt motor 19B. Lower. As a result, the plunger 5 moves forward at the speed V _S.

  In the initial injection process and the ultra-low speed injection process, when the nut 13 moves forward, a backward force is applied to the bolt 15 according to the law of action and reaction. This backward force is received by a fixed member. Specifically, for example, the injection piston 31 is positioned at the retreat limit, and the cylinder member 29 has a stopper (not shown) included in the cylinder piston 29 (or the pressure increasing piston 33 that is in contact with the rear end portion of the cylinder member 29). Abut. The cylinder member 29 is fixed to the support frame 115 and the base 113 as described above. A backward force applied to the bolt 15 is received by the support frame 115 and the base 113 via the piston rod 35, the injection piston 31 and the cylinder member 29.

  In the initial injection process and the ultra-low speed injection process, for example, the control device 111 feeds back the rotation speed of the nut motor 19N and / or the bolt motor 19B based on the detection result of the position sensor 47. It is realized by controlling. The rotational speeds of the two electric motors 19 may be the same or different from each other.

(After ultra-low speed injection process)
Although not shown in particular, when the molten metal is filled in the cavity 105 to some extent by the ultra-low speed injection process, the plunger 5 receives the reaction force from the filled molten metal and is decelerated, while the injection pressure increases. Go. Thereafter, the control of the electric motor 19 is switched to, for example, torque control, and is controlled so as to generate a predetermined torque. Thereby, pressure increase and holding pressure are performed.

  After that, when the molten metal solidifies, the control device 111 opens the mold with a mold clamping device (not shown), and pushes out the molded product from the mold with an extrusion device (not shown), as in the standard injection method. At this time, the injection device 1 may perform an operation of pushing a biscuit. The said operation | movement is implement | achieved by the driving force of the electric drive part 7, for example.

  Further, the control device 111 drives the motor 19N for nuts and the motor 19B for bolts in directions opposite to those when the plunger 5 is advanced so as to return the plunger 5 to the initial position. The plunger 5 may be moved backward by driving only one of the nut motor 19N and the bolt motor 19B.

  As described above, in the present embodiment, the injection device 1 is interposed between the injection cylinder device 9 in which the cylinder member 29 is fixedly disposed, the plunger 5 and the piston rod 35 of the injection cylinder device 9, and these are arranged. A screw mechanism 12 that can be relatively moved in the front-rear direction and a nut motor 19N that rotates a nut 13 of the screw mechanism 12 are provided.

  Therefore, for example, the nut motor 19N does not need to generate a driving force for moving the injection cylinder device 9, and the burden on the nut motor 19N is reduced. As a result, for example, the need for customizing a large electric motor 19 is reduced, and cost reduction is expected.

  When high-pressure hydraulic fluid is supplied to the injection cylinder device 9, a force is generated to move the cylinder member 29 backward. This embodiment is not an aspect in which the injection cylinder device is moved by an electric motor, and the cylinder member 29 is fixedly provided, so that the rearward movement of the cylinder member 29 is firmly prevented. As a result, for example, the injection piston 31 can be effectively moved forward, and acceleration at the time of switching from the low speed injection process to the high speed injection process can be suitably performed.

  Further, in the present embodiment, the control device 111 of the injection device 1 performs an ultra-low speed injection method that drives only the nut motor 19N among the injection cylinder device 9 and the nut motor 19N from the start of injection to the completion of injection (in a narrow sense). The injection cylinder device 9 and the injection cylinder device 9 and the standard injection method for driving at least the injection cylinder device 9 among the injection cylinder device 9 and the nut motor 19N from the start of injection to the completion of injection (in a narrow sense) and The nut motor 19N is controlled.

Therefore, the controllability of the injection speed is improved in the ultra-low speed injection method. For example, there is a large difference between the speed V _S (as an example, 0.01 m / s) of the ultra-low speed injection process and the speed V _H (10 m / s as an example) of the high speed injection process. Therefore, if both speeds are to be realized by the injection cylinder device, the flow rate of the hydraulic fluid supplied to the injection cylinder device is greatly different between the ultra-low speed injection process and the high speed injection process (for example, 1000 times). It is difficult to control the flow rate with a servo valve. In particular, it is difficult to realize minute flow rate control. However, by realizing the ultra-low speed injection method with an electric motor, such inconvenience is eliminated.

  In addition, in the ultra-low speed injection method, the repetition accuracy of the injection speed is also improved. For example, when the ultra-low speed injection method is performed by the injection cylinder device, disturbance is caused by the temperature of the working fluid, the bubble mixing rate, and various other factors in the speed control, and the repetition accuracy of the injection speed is lowered. However, by realizing the ultra-low speed injection method with an electric motor, such inconvenience is eliminated.

  Thus, in the present embodiment, an ultra-low injection speed can be realized with high accuracy, while a high-speed injection speed necessary for a high-speed injection process can be realized. As a result, there is no need to prepare a dedicated machine for the ultra-low speed injection method.

  Moreover, in this embodiment, the injection device 1 further includes an output pulley 27N that is not rotatable with the nut 13 and is relatively movable in the front-rear direction. The nut motor 19N is fixedly arranged, and the rotation thereof is transmitted to the nut 13 by being transmitted to the output pulley 27N.

  That is, the nut motor 19N does not need to be provided so as to be movable in the front-rear direction together with the nut 13. Accordingly, the nut motor 19N does not need to generate a driving force for moving itself in the front-rear direction. As a result, reduction of the burden on the nut motor 19N is expected. Further, in the injection cylinder device 9, it is not necessary to generate a driving force for moving the nut motor 19N. As a result, for example, it is easy to obtain an injection speed necessary for high-speed injection.

  In the present embodiment, the injection device 1 further includes a flexible belt 25N that extends in an annular shape and is hung on the output pulley 27N, and an input pulley 23N on which the belt 25N is hung. The rotation of the nut motor 19N is transmitted to the nut 13 by being sequentially transmitted to the input pulley 23N, the belt 25N, and the output pulley 27N.

  Therefore, for example, the rotation of the nut motor 19N can be appropriately changed. Further, for example, the distance between the nut motor 19N and the output pulley 27N can be set as appropriate. As a result, for example, it is easy to separate the nut motor 19N from the high-temperature atmosphere near the sleeve 3.

  In the present embodiment, the injection device 1 further includes a bolt motor 19 </ b> B that rotates the bolt 15.

  Therefore, for example, the rotation of the bolt 15 in the same direction as the nut 13 can be suppressed by the driving force of the bolt motor 19B. Further, for example, when the nut 13 is pushed backward by the surge pressure at the completion of the filling of the molten metal, the bolt 15 is rotated and the nut 13 is retracted by the driving force of the bolt motor 19B.

  Further, in the present embodiment, the nut motor 19N and the bolt motor 19B are controlled so as to advance the plunger 5 by rotating the nut 13 and the bolt 15 in opposite directions, so that only the nut 13 is rotated. Compared to the case, it is easy to realize a high speed.

  If the ultra-low speed injection process is divided into a low speed process and a high speed process in the standard injection method, it can be regarded as corresponding to the low speed process from the relationship of injection speed. That is, it can be understood that the ultra-low speed injection method realizes the low speed process in the standard injection method.

(Modification of operation of each part in standard injection method)
In the description of the above-described embodiment, a case has been described in which only the injection cylinder device 9 is basically used and the electric drive unit 7 is not used in the standard injection method. However, the electric drive unit 7 may also be used in the standard injection method. For example, it is as follows.

  In the above-described FIG. 5 (“electric drive unit” and “ACC” portions), a first modified example of the operation of each unit in the standard injection method is shown by a one-dot chain line.

  In the first modification, the low-speed injection process is realized by the driving force of the electric drive unit 7. The details are substantially the same as the initial injection process of the ultra-low speed injection method.

  In the first modification, the high-speed injection process is realized by the driving force of the injection cylinder device 9 as in the high-speed injection process of the standard injection method of the embodiment. The details are almost the same as the high-speed injection process of the standard injection method.

  In the high-speed injection process, the relative position of the nut 13 and the bolt 15 is the position at the time of switching from the low-speed injection process to the high-speed injection process. The suppression of the relative backward movement of the nut 13 with respect to the bolt 15 is, for example, that the nut 13 is constituted by a sliding screw mechanism, the lead angle is increased, and / or the driving force or brake of the electric motor 19 is output. This is realized by restricting the rotation of the pulley 27 or the like.

  In this modification, the accumulator 43 does not need to supply hydraulic fluid to the injection cylinder device 9 in the low speed injection process. Therefore, at least a part of the filling process of the accumulator 43 may overlap with the low-speed injection process.

  In the embodiment, in the low-speed injection of the standard injection method, the working fluid is supplied from the accumulator 43 to the injection cylinder device 9. However, hydraulic fluid may be supplied from the pump 39 to the injection cylinder device 9 instead of the accumulator 43. Specifically, it is as follows.

  In FIG. 5 (portion “Pump”), a two-dot chain line indicates a second modification of the operation of each part in the standard injection method.

  In the second modification, the hydraulic fluid is supplied from the pump 39 to the head side chamber 29h, and the low speed injection is performed. The speed control of the plunger 5 at this time may be performed by a meter-in circuit and / or a meter-out circuit, for example, as in the embodiment, and the rotational speed of the pump 39 is feedback controlled based on the detection result of the position sensor 47. It may be done by doing.

  Thereafter, as in the first modification, the working fluid of the accumulator 43 is supplied to the injection cylinder device 9 and high-speed injection is performed. The details are the same as in the embodiment.

<Second Embodiment>
FIG. 6 is a cross-sectional view from the side schematically showing the configuration of the main parts of the die casting machine DC 201 and the injection apparatus 201 according to the second embodiment of the present invention. In addition, about the structure same or similar to the injection device 1 of 1st Embodiment, the code | symbol same as the code | symbol of 1st Embodiment may be attached | subjected, and description may be abbreviate | omitted.

  The injection device 201 is different from the injection device 1 of the first embodiment only in the configuration related to the bolt. That is, the bolt 15 of the first embodiment is rotatably provided, and the rotation of the bolt motor 19B is transmitted, whereas the bolt 215 of the present embodiment is restricted from rotating. The electric motor 19B is not provided.

  More specifically, for example, one or more guide shafts 117 extending forward are fixed to the support frame 115. A guide shaft 117 is inserted through the bolt 215. As a result, the bolt 215 is restricted in rotation and is movable in the front-rear direction.

  The operation of the injection device 201 of the present embodiment is the same as the operation of the injection device 1 of the first embodiment except that the bolt 215 is not rotated. In addition, when the injection speed equivalent to the injection speed by the electric drive unit 7 of the first embodiment is realized by the electric drive unit 207 of the present embodiment, the nut 13 is rotated at a higher speed than the first embodiment. Appropriate concrete changes such as these are necessary.

  As described above, the injection device 201 is interposed between the injection cylinder device 9 in which the cylinder member 29 is fixedly disposed, and the plunger 5 and the piston rod 35 of the injection cylinder device 9. Has a screw mechanism 212 that can be relatively moved in the front-rear direction, and a nut motor 19N that rotates the nut 13 of the screw mechanism 212.

  Therefore, also in the second embodiment, the same effect as in the first embodiment is achieved. For example, the burden on the electric motor is reduced, and the retreat of the cylinder member 29 in high-speed injection is firmly regulated.

  In the first and second embodiments described above, the nut 13 is an example of one of the male screw member and the female screw member and the female screw member, and the bolts 15 and 215 are the other of the male screw member and the female screw member, and the male screw. The nut motor 19N is an example of a first motor (electric motor), the output pulley 27N is an example of a first rotating member (rotating member), and the belt 25N is an example of a long member. The input pulley 23N is an example of a second rotating member (rotating member), the bolt motor 19B is an example of a second electric motor (electric motor), the guide shaft 117 is an example of a rotation restricting member, and the die casting machines DC1 and DC201. Is an example of a molding apparatus.

  In the first embodiment, contrary to the above, the bolt 15 may be an example of one of a male screw member and a female screw member, and the nut 13 may be regarded as an example of the other of the male screw member and the female screw member. Similarly, the nut motor 19N is an example of a second motor (electric motor), the output pulley 27B is an example of a first rotating member (rotating member), the belt 25B is an example of a long member, and the input pulley 23B. Is an example of the second rotating member (rotating member), and the bolt motor 19B may be regarded as an example of the first electric motor (electric motor).

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

  The 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, or a molding machine that molds a material obtained by mixing wood powder with a thermoplastic resin or the like. . Further, the molding machine is not limited to horizontal mold clamping horizontal injection, and may be vertical mold clamping vertical injection, vertical mold clamping horizontal injection, horizontal mold clamping vertical injection, for example. The hydraulic fluid is not limited to oil and may be water, for example.

  The injection device (control device) may not be able to execute the ultra-low speed injection method, and may be able to execute only the standard injection method. Further, in the ultra-low speed injection method or the standard injection method, the roles of the electric drive unit and the injection cylinder device may be set as appropriate. For example, in the standard injection method, the biscuit may be pushed out by an electric drive unit. Although the present invention can reduce the load on the electric motor, it may be divided into roles that increase the load on the electric motor. For example, in the high-speed injection of the standard injection method, the nut 13 may be advanced with respect to the bolt 15 in addition to the advance of the piston rod.

  The number of screwing members (a male screw member and a female screw member) is not limited to two, and three or more may be provided. For example, a first nut that is fixed to the plunger and whose rotation is restricted, a second nut that is fixed to the piston rod and whose rotation is restricted, and a screw bolt that is screwed into the first nut and the second nut are provided. May be. Then, the plunger may be moved backward or forward by rotating both screw bolts with an electric motor and causing the first nut and the second nut to approach or separate from each other.

  Whether the male screw member and the female screw member are set to the plunger side and the piston rod side may be appropriately set. For example, when the number of screwing members is two as in the embodiment, the male screw member is not movable in the front-rear direction with respect to the plunger, and the female screw member is not movable relative to the piston rod. It may be impossible to move in the front-rear direction.

  When only one of the screwing members that are screwed together is rotated as in the second embodiment, it may be rotated on either the plunger side or the piston rod side. For example, in the embodiment, the rotation of the nut 13 may be restricted and only the bolt 15 may be rotated.

  The first electric motor may rotate not only one of the male screw member and the female screw member but also the other of the male screw member and the female screw member. For example, the rotation of one electric motor may be transmitted to both the male screw member and the female screw member via an appropriate gear mechanism or the like, and the male screw member and the female screw member may rotate in directions opposite to each other.

  The first rotating member that cannot be rotated relative to the screwing member (the male screw member or the female screw member) rotated by the first electric motor and that is relatively movable in the front-rear direction may not be provided. In another aspect, the first electric motor may be provided to be movable in the front-rear direction. The same applies to the second electric motor. Further, the first rotating member and the screwing member may be provided with grooves (or protrusions).

  The transmission mechanism between the electric motor and the screwing member may be appropriately configured. For example, the transmission mechanism may include a gear mechanism. In the case where the transmission mechanism includes a flexible long member that extends in an annular shape, the long member is not limited to a belt, and may be a chain.

  The injection cylinder device is not limited to a pressure-increasing type, and may be a single-acting type that does not have a pressure-increasing piston.

  DESCRIPTION OF SYMBOLS 1 ... Injection apparatus, 3 ... Sleeve, 5 ... Plunger, 9 ... Injection cylinder apparatus, 13 ... Nut (one of a male screw member and a female screw member), 15 ... Bolt (the other of a male screw member and a female screw member), 19N ... Electric motor for nuts (1st electric motor), 35 ... piston rod, 105 ... cavity.

Claims (7)

A plunger capable of moving back and forth in the sleeve;
An injection cylinder device having a fixedly arranged cylinder member, a piston accommodated in the cylinder member so as to be slidable in the front-rear direction, and a piston rod fixed to the piston;
It has a male screw member and a female screw member interposed between the plunger and the piston rod, and the plunger and the piston rod can be relatively moved in the front-rear direction by relative rotation around the axis of the male screw member and the female screw member. Screw mechanism,
An electric motor for rotating at least one of the male screw member and the female screw member;
Injection device with. A rotating member that is non-rotatable with the one of the male screw member and the female screw member and is relatively movable in the front-rear direction;
The injection device according to claim 1, wherein the electric motor is fixedly disposed, and rotation thereof is transmitted to the one of the male screw member and the female screw member by being transmitted to the rotating member. The rotating member includes a first rotating member that is not rotatable with respect to the one of the male screw member and the female screw member and is relatively movable in the front-rear direction, and a second rotating member,
A flexible elongate member extending annularly and being hung on the first rotating member and the second rotating member;
The injection according to claim 2, wherein the rotation of the electric motor is transmitted to the one of the male screw member and the female screw member by being sequentially transmitted to the second rotating member, the long member, and the first rotating member. apparatus. 4. The motor according to claim 1, further comprising: a first motor that rotates one of the male screw member and the female screw member; and a second motor that rotates the other of the male screw member and the female screw member. The injection device according to item. The injection device according to claim 4, wherein the first electric motor and the second electric motor are controlled such that the male screw member and the female screw member are rotated in opposite directions to advance the plunger. The injection device according to claim 1, further comprising a rotation restricting member that restricts rotation of the other of the male screw member and the female screw member.   The shaping | molding apparatus which has the injection apparatus of any one of Claims 1-6.

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