JP6186609B2 - Injection device and molding device - Google Patents

Description

  The present invention relates to a molding machine (molding apparatus) and an injection apparatus thereof. The molding machine 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 of Patent Document 1 or 2 includes an injection cylinder connected in series to a plunger, and a ball screw mechanism that is arranged in parallel to the injection cylinder and driven by an electric motor. The ball screw mechanism is provided such that the nut moves in the axial direction with respect to the screw shaft. Moreover, the injection device has an attachment / detachment portion for attaching / detaching a piston rod (plunger) of the injection cylinder and a nut of the ball screw mechanism.

  And the injection device of patent documents 1 or 2 drives a plunger by a ball screw mechanism (electric motor) in the state where a nut and a plunger were connected by an attaching-and-detaching part in low-speed injection, and then from low-speed injection to high-speed injection. At the time of switching, the connection by the detachable portion is released, and the plunger is driven by the injection cylinder in high-speed injection.

  As described above, in the technique of Patent Document 1 or 2, the speed of the plunger is accurately controlled by the electric motor in the low-speed injection, and the plunger and the ball screw mechanism are separated from each other in the high-speed injection. This eliminates the inconvenience of being limited by the speed, and realizes a high injection speed with hydraulic equipment.

Japanese Patent No. 4790869 Japanese Patent No. 4960527

  In the vicinity of the sleeve, the molding material supplied to the sleeve scatters, or a lubricant for lubrication between the sleeve and the plunger scatters. When the scattered molding material or lubricant adheres to the ball screw mechanism or the like, there is a possibility that these performance deterioration or life shortening may occur. Therefore, it is desired to provide an injection device and a molding device that can improve the operating environment of the drive device.

  The injection device of the present invention has a sleeve that communicates with a cavity, a plunger that pushes the molding material in the sleeve into the cavity, an injection cylinder that has a piston rod connected to the plunger, and a drive device. The drive device rotates a screw shaft parallel to the piston rod, a nut threadedly engaged with the screw shaft, and a rotating member that is one of the screw shaft and the nut, whereby the other of the screw shaft and the nut is rotated. An electric motor that generates a driving force for moving the moving member in a direction parallel to the piston rod, and the moving member moves together with the moving member, and the relative advance with respect to the piston rod is restricted, and the relative movement with respect to the piston rod is restricted. A regulated member that is allowed to retreat, and the screw shaft includes the nut in the injection cycle. Flip has a threaded portion which is a range that moves relative to the axis, the threaded portion and the nut is located rearward than the the controlled member over the injection cycle.

  Preferably, the rotating member is the screw shaft, the moving member is the nut, and the driving device extends in a direction parallel to the piston rod, and one end side is fixed to the nut and the other end side is A relay member fixed to the regulated member;

  Preferably, the rotating member is the nut, the moving member is the screw shaft, the screw shaft is located in front of the screwing portion, and a connecting portion to which the regulated member is fixed. And an intermediate portion located between the connecting portion and the screwing portion.

  The molding device of the present invention includes any one of the above-described injection devices and a mold clamping device.

  ADVANTAGE OF THE INVENTION According to this invention, the operating environment of the drive device with which connection with a plunger and the cancellation | release are made can be improved.

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. The schematic diagram which shows the structure of the principal part of the injection apparatus of the die-casting machine of FIG. The figure explaining operation | movement of the injection apparatus of FIG. The schematic diagram which shows the structure of the principal part of the injection device which concerns on the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the second and subsequent embodiments, configurations that are the same as or similar to the configurations of the embodiments that have already been described may be denoted by the same reference numerals as those of the embodiments that have already been described, and description thereof may be omitted. .

<First Embodiment>
FIG. 1 is a side view (partly including a cross-sectional view) schematically showing a configuration of a main part of a die casting machine DC1 according to a first embodiment of the present invention.

  In the following, the left side in FIG. 1 (the direction in which the plunger 5 moves 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 in FIG.

  The die casting machine DC1 includes, for example, a mold clamping device 151 that clamps the fixed mold 101 and the movable mold 103, and a cavity 105 that includes the fixed mold 101 and the movable mold 103 that are clamped to the mold clamping device 151. An injection device 1 for injecting and filling molten metal (a molten metal material) as a molding material (material) and a die-cast product (molded product) that is molded (not shown) are extruded from the fixed mold 101 or the moving mold 103. It has an extrusion device and a control device 153 for controlling these devices. Note that the control device 153 may be regarded as constituting a part of each device.

  The mold clamping device 151 is, for example, a base (not shown), a fixed die plate 155 fixed on the base and holding the fixed mold 101, and movable in the mold opening / closing direction on the base. And a movable die plate 157 for holding.

  An injection frame 159 is fixed to the fixed die plate 155. The injection frame 159 may be an appropriate type such as a C type or a D type. As will be described later, the injection frame 159 is used for fixing the injection device 1 to the mold clamping device 151, and may be regarded as a part of the injection device 1.

(Configuration of injection device)
FIG. 2 is a top view (partly including a cross-sectional view) schematically showing a configuration of a main part of the injection apparatus 1.

  The injection device 1 includes a sleeve 3 (see also FIG. 1) that communicates with the cavity 105, a plunger 5 that pushes the molten metal in the sleeve 3 to the cavity 105, an injection cylinder 9 that drives the plunger 5, and hydraulic fluid to the injection cylinder 9. A hydraulic device 11 to be supplied and a driving device 13 for driving the plunger 5 are provided.

  The configuration of the sleeve 3 and the plunger 5 may be the same as a known configuration. The sleeve 3 is provided so as to be inserted through the fixed die plate 155, for example. The sleeve 3 may be inserted through the fixed mold 101. The plunger 5 has a plunger tip 5a that slides on the sleeve 3, and a plunger rod 5b fixed to the plunger tip 5a.

  In the present application, as a general rule, “fixing” is not only performed when two or more members formed separately from each other are fixed, but also fixed by forming two or more members integrally. The term “connection” refers to a case where two or more members formed separately are fixed (or engaged), and are fixed by forming two or more members integrally. It shall not include the case where

  When the molten metal is supplied into the sleeve 3 from the hot water supply port 3a (see also FIG. 1) formed in the sleeve 3, the plunger tip 5a slides (advances) in the sleeve 3 toward the cavity 105. The molten metal is injected and filled into the cavity 105.

  Note that the rear end of the stroke of the plunger 5 is, for example, a position where the front portion of the plunger tip 5a is inserted into the rear end of the sleeve 3 as shown in FIG. In addition, the front end of the stroke of the plunger 5 is a position where an appropriate biscuit thickness is secured.

  The length of the plunger 5 is roughly equivalent to the stroke of the plunger 5. However, the length of the plunger 5 is such that the rear end portion of the plunger rod 5b is located outside the sleeve 3 when the plunger 5 is located at the front end of the stroke.

  The injection cylinder 9 is constituted by, for example, a direct connection type pressure increasing cylinder. That is, the injection cylinder 9 includes a cylinder member 15, an injection piston 17 and a pressure increasing piston 19 that can slide inside the cylinder member 15, and a piston rod 21 that is fixed to the injection piston 17 and exposed from the cylinder member 15. Have.

  The cylinder member 15 includes an injection cylinder portion 15a and a pressure increasing cylinder portion 15b that is located behind the injection cylinder portion 15a and has a larger diameter than the injection cylinder portion 15a. The injection piston 17 is slidable on the injection cylinder portion 15a, and divides the inside of the injection cylinder portion 15a into a front rod side chamber 15r and an opposite head side chamber 15h. The pressure increasing piston 19 has a small diameter portion 19a that can slide the injection cylinder portion 15a and a large diameter portion 19b that can slide the pressure increasing cylinder portion 15b. The large diameter portion 19b divides the inside of the pressure increasing cylinder portion 15b into a front front chamber 15f and a rear rear chamber 15e.

  When the hydraulic fluid is supplied to the head side chamber 15h, the injection piston 17 moves forward. In addition, when hydraulic fluid is supplied to the rear chamber 15e in a state where the hydraulic fluid is prohibited from flowing out from the head side chamber 15h and the front chamber 15f is at tank pressure, the pressure receiving area before and after the pressure increasing piston 19 is reduced. The hydraulic fluid in the head side chamber 15h is increased according to the difference.

  The injection cylinder 9 is disposed coaxially (in series) behind the plunger 5. The tip of the piston rod 21 is connected to the rear end of the plunger 5. Accordingly, as the piston rod 21 moves forward and backward, the plunger 5 also moves forward and backward.

  In addition, since the plunger 5 and the piston rod 21 are coaxially arranged and connected to each other, other members other than these are particularly parallel to the plunger 5 and parallel to the piston rod 21. It may be expressed without distinction, and similarly, it may be expressed without particular distinction between other members connected to the plunger 5 and connected to the piston rod 21. .

  The plunger 5 and the piston rod 21 are connected by a coupling 23. The coupling 23 includes, for example, a spacer 25 interposed between the rear end of the plunger 5 and the front end of the piston rod 21 and a cover 27 covering these. The cover 27 has a contacted portion 27 b that is used for connection with the driving device 13. The contacted portion 27b has, for example, a flange portion.

  The stroke of the injection cylinder 9 defines, for example, a forward limit provided in the injection cylinder portion 15a from a position where the injection piston 17 contacts a stopper (not shown) that defines a backward limit provided in the injection cylinder portion 15a. This is the distance to the position where it abuts against a stopper (not shown). The stopper may be constituted by the inner surface of the end of the cylinder member 15.

  The stroke of the injection cylinder 9 is slightly longer than the stroke of the plunger 5, for example. Preferably, the plunger 5 is in a state in which the distal end portion of the plunger tip 5a is inserted into the rear end of the sleeve 3 when the injection piston 17 is located at the backward limit, and the injection piston 17 is slightly before the forward limit. When located, it is located at a position where an appropriate biscuit thickness is secured.

  The hydraulic device 11 includes, for example, a tank 29 that stores hydraulic fluid, a pump 31 that sends hydraulic fluid from the tank 29, a pump motor 33 that drives the pump 31, and an accumulator 35 that supplies accumulated hydraulic fluid. And a hydraulic circuit 37 for connecting these elements and the injection cylinder 9 to each other.

  The tank 29 is an open tank, for example, and holds the working fluid under atmospheric pressure. For example, the tank 29 eliminates the excess or deficiency of the hydraulic fluid in the injection cylinder 9 via the hydraulic circuit 37, and supplies the hydraulic fluid to the accumulator 35 via the pump 31 and the hydraulic circuit 37.

  The pump 31 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 31 may be constituted 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 constituted by a variable displacement pump in which the discharge amount is variable. The pump 31 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 33 is a rotary electric motor. The pump motor 33 may be a DC motor or an AC motor, or may be an induction motor or a synchronous motor. The pump motor 33 may function as a constant-speed motor provided in an open loop, or may function as a servo motor provided in a closed loop.

  In the description of the operation described later, when the pump motor 33 is stopped, the pump motor 33 may be in a torque-free state, or (in the case of a servo motor), stopped at a fixed position. It may be controlled to include the brake, and the brake may be used. An appropriate stopping method may be selected according to the situation where the pump motor 33 is stopped.

  The accumulator 35 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 35 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 35. The accumulated hydraulic fluid is supplied to the injection cylinder 9 via the hydraulic circuit 37.

  Although not particularly shown, the hydraulic circuit 37 includes a plurality of flow paths that connect the injection cylinder 9, the tank 29, the pump 31, and the accumulator 35, and a plurality of valves that control the flow of hydraulic fluid in the plurality of flow paths. have. 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 hydraulic circuit 37 may be appropriately configured so as to realize a flow of hydraulic fluid described later.

  In FIG. 2, a servo valve 39 for controlling the flow rate of the hydraulic fluid discharged from the rod side chamber 15r is illustrated as a component of the hydraulic circuit 37. The servo valve 39 constitutes a meter-out circuit. That is, the forward speed of the piston rod 21 is controlled by controlling the flow rate of the hydraulic fluid discharged from the rod side chamber 15r by the servo valve 39.

  The drive device 13 is driven in the front-rear direction by the drive motor 41, the screw mechanism 43 that transmits the drive force of the drive motor 41, and the drive force transmitted from the screw mechanism 43, and is driven by the plunger 5 (piston rod 21). An attachment / detachment part 45 that can be attached / detached is provided. The drive device 13 has, for example, two sets of the combination of the drive motor 41, the screw mechanism 43, and the attaching / detaching portion 45 symmetrically.

  The drive motor 41 is a rotary motor and has a stator that constitutes one of the armature or the field and a rotor that constitutes the other of the armature or the field, as is well known, although not particularly illustrated. ing. The stator is fixed by an appropriate method to restrict various parallel movements and rotational movements, and the rotor rotates about its axis with respect to the stator. The drive motor 41 is arranged with the axial direction parallel to the piston rod 21.

  The drive motor 41 may be a DC motor or an AC motor, or may be an induction motor or a synchronous motor. The drive motor 41 is preferably a motor with a brake. The drive motor 41 is configured as a servo motor, for example, and constitutes a servo mechanism together with an encoder 47 that detects the rotation of the drive motor 41 and a servo driver 49 that supplies power to the drive motor 41.

  In the description of the operation to be described later, when the drive motor 41 is stopped, an appropriate stop method may be selected according to the situation in which the drive motor 41 is stopped, as in the case of the pump motor 33.

  The screw mechanism 43 is configured by, for example, a ball screw mechanism, and includes a screw shaft 51 and a nut 53 that is screwed onto the screw shaft 51 via a ball (not shown).

  The screw shaft 51 is disposed in parallel to the piston rod 21. Further, the screw shaft 51 is allowed to move in the axial direction and is restricted from rotating around the axis by being fixed to the detachable portion 45. On the other hand, the nut 53 is disposed concentrically inside the rotor of the drive motor 41 and is fixed to the rotor. The nut 53 is restricted from moving in the axial direction and is allowed to rotate about the axis.

  Therefore, when the drive motor 41 is driven, the nut 53 rotates and the screw shaft 51 moves in parallel (in the front-rear direction) with the piston rod 21. In a state where the screw shaft 51 and the plunger 5 are connected by the detachable portion 45, when the drive motor 41 is driven, the plunger 5 moves in the front-rear direction together with the screw shaft 51.

  The screw shaft 51 has a threaded portion 51a into which the nut 53 is screwed, a connecting portion 51b that is coupled to the piston rod 21 by an attaching / detaching portion 45 at the front thereof, and an intermediate portion 51c therebetween. For example, the middle portion 51c is not threaded in all or most of the middle portion 51c.

  In addition, the screwing part 51a does not say the whole in which the thread groove is cut in the screw shaft 51, but the range (the nut in which the nut 53 relatively moves in the cycle (injection cycle) of the operation performed by the injection device 1). 53 is a range in which the screw is engaged over the injection cycle). Therefore, for example, even if a screw groove is cut in the entire screw shaft 51, the screw shaft 51 does not have the intermediate portion 51c by itself. Further, in such a screw shaft 51 that is entirely thread-grooved, even if the thread groove cut to the front side of the range in which the nut 53 moves in the injection cycle is used for some purpose other than the injection cycle. The screw shaft 51 does not have the intermediate portion 51c.

  The rear end of the range in which the thread groove is cut does not affect the determination of the presence or absence of the intermediate portion 51c. Further, the rear end of the screw shaft 51 in which the nut 53 moves relatively (the rear end of the threaded portion 51a) varies depending on the setting change of the biscuit thickness or the use of a short sleeve. Therefore, the rear end of the threaded portion 51a may be the rear end of the range where the thread groove is cut.

  In the present embodiment, for example, as shown in FIG. 2, the front end of the threaded portion 51a is connected to the piston rod 21 by the connecting portion 51b and the injection piston 17 is not shown in the injection cylinder portion 15a. This is a position where the nut 53 is screwed when it is at a position where the backward movement is restricted by the stopper (reverse limit). The attaching / detaching portion 45 may be a position where it comes into contact with a stopper (not shown) provided on the injection frame 159.

  The connecting portion 51b refers to a portion of the screw shaft 51 that directly contributes to the connection with the piston rod 21. For example, in the present embodiment, the connecting portion 51 b is a portion that contacts the member (base portion 55) included in the attaching / detaching portion 45 of the screw shaft 51. More specifically, the connecting portion 51b is from the rear end surface of the flange-shaped portion 51f formed at the tip to the front end surface of the rear flange-shaped portion 51e. Therefore, for example, even if the rear flange-like portion 51e is formed thicker (longer) on the rear side, the length of the intermediate portion 51c is not evaluated to be shorter.

  The screw shaft 51 of the screw shaft 51 and the nut 53 is configured to move in the front-rear direction, and the connecting portion 51b is provided in front of the screwing portion 51a, so that the screwing portion 51a and the nut 53 are , Located behind the attaching / detaching portion 45 over the injection cycle. Furthermore, since the intermediate part 51c is provided in the screw shaft 51, the screwing part 51a and the like are located further rearward. As a result, the molten metal or lubricant supplied to the sleeve 3 is prevented from being scattered to the screwing portion 51a and the like, and the screwing portion 51a and the like are protected.

  From the viewpoint of protecting the threaded portion 51a and the like, the intermediate portion 51c is preferably as long as possible. On the other hand, if the intermediate portion 51c is too long, the rear end of the screw shaft 51 protrudes rearward, and the injection device 1 becomes longer.

  Therefore, in the present embodiment, the length of the intermediate portion 51c is set so that the rear end of the screw shaft 51 coincides with the rear end of the injection cylinder 9 when the screw shaft 51 is positioned at the retreat limit in the injection cycle. ing. Thereby, the intermediate part 51c is enlarged to the maximum while avoiding lengthening of the injection device 1.

  In this case, for example, if the length of the threaded portion 51 a and the stroke of the injection cylinder 9 are substantially the same, the length of the intermediate portion 51 c is approximately the thickness of the injection frame 159 and the front end surface of the cylinder member 15. This is a length obtained by adding the thickness of the (rod cover) and the distance from the rear end surface of the injection piston 17 located at the backward limit to the rear end of the cylinder member 15.

  The various lengths described above differ for each specific product (die casting machine). However, for example, empirically, the thickness of the front end surface of the cylinder member 15 can be estimated to be approximately 1/10 or more of the stroke of the injection cylinder 9, and the thickness of the injection frame 159 is approximately the stroke of the injection cylinder 9. It can be estimated that 1/10 or more. Therefore, even if the size of the pressure increasing cylinder portion 15b is underestimated, the intermediate portion 51c (or the portion where the thread groove of the intermediate portion 51c is not cut) has a length exceeding 1/5 of the stroke of the injection cylinder 9. have.

  Further, for example, from experience, the size of the pressure increasing cylinder portion 15 b can be estimated to be approximately 1/5 or more of the stroke of the injection cylinder 9. Accordingly, in the present embodiment, the intermediate portion 51c has a length exceeding 1/3.

  The detachable portion 45 includes a base portion 55, a hook 57 that is swingably supported by the base portion 55, and an actuator 59 that drives the hook 57.

  The base portion 55 is fixed to the connecting portion 51 b of the screw shaft 51. Therefore, the base 55 is driven in the front-rear direction together with the screw shaft 51 by the driving force of the drive motor 41. Further, as the base portion 55 moves in the front-rear direction, the hook 57 and the actuator 59 supported by the base portion 55 also move in the front-rear direction.

  The base portion 55 has a plate-like portion in which a hole portion through which the piston rod 21 is inserted is formed, and can come into contact with the contacted portion 27b of the coupling 23 from the rear. That is, the base 55 is restricted from advancing relative to the piston rod 21 by contact with the contacted portion 27b, and is allowed to move backward relative to the piston rod 21 from the contact position.

  Therefore, the plunger 5 can be advanced by advancing the base 55 in a state where the base 55 is in contact with the contacted portion 27b. That is, the plunger 5 can be moved forward by the driving force of the drive motor 41. Further, the plunger 5 can be moved forward relative to the base portion 55 by supplying hydraulic fluid to the head side chamber 15 h and moving the piston rod 21 at a relatively high speed.

  The base portion 55 has a buffer portion made of a material having a smaller coefficient of rebound from the abutted portion 27b than the other portions of the base portion 55 as a portion that abuts on the abutted portion 27b. Is preferred.

  The base 55 (a member to be regulated) is fixed to a connecting portion 51b positioned in front of the screwing portion 51a. That is, the screwing part 51a and the nut 53 are located behind the base part 55 over the injection cycle. The determination as to whether or not the screwing part 51a (the whole) or the like is located behind the base part 55 is a part of the base part 55 that directly contributes to the restriction of the forward movement relative to the piston rod 21 (this embodiment). In the embodiment, the base 55 is assumed to be formed based on the position of the surface abutting the contacted portion 27b. Therefore, for example, even if the base 55 has a guide shaft extending rearward, it does not affect the determination as to whether or not the screwing portion 51a is located rearward of the base 55.

  For example, the hook 57 is generally L-shaped, and one end is rotatably supported by the base 55. The hook 57 can be engaged with the contacted portion 27b in the retracting direction of the plunger 5 ("ON" position), and the disengaged position ("OFF" position). Can be moved between. The hook 57 can hold the contacted portion 27b with the base portion 55 at the ON position.

  When the hook 57 is turned off (disengaged), the plunger 5 can be moved forward relative to the base 55. Further, when the hook 57 is turned on (engaged), the plunger 5 can be retracted as the base 55 is retracted. That is, the plunger 5 can be moved backward by the driving force of the drive motor 41.

  The drive device 13 is configured and arranged so that the hook 57 can be engaged with the contacted portion 27b over the entire stroke of the injection piston 17. For example, the stroke of the screw mechanism 43 is equivalent to the stroke of the injection cylinder 9, and the driving device 13 is arranged so that the screw shaft 51 is also positioned in the backward limit when the injection piston 17 is in the backward limit. ing.

  The actuator 59 is constituted by, for example, an actuator that performs reciprocating motion (extending and contracting from another viewpoint). The actuator 59 is, for example, a linear motor, a pneumatic cylinder, or a hydraulic cylinder. The hook 57 is turned on or off by the reciprocation of the actuator 59.

  The control device 153 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 153 outputs a control signal for controlling each unit based on various input signals.

  The signal is input to the control device 153, for example, by an input device (not shown) that receives a user input operation, an encoder 47, a position sensor 65 for detecting the position of the plunger 5, and an appropriate position in the hydraulic system. It is a pressure sensor (not shown) that detects the pressure of the liquid.

  The controller 153 outputs a signal, for example, a display (not shown) that displays information to the user, a servo driver 49, a driver (not shown) that supplies power to the pump motor 33, and a hydraulic circuit 37 (servo valve 39), and an actuator 59 (or a driver thereof).

  For example, the position sensor 65 constitutes a linear encoder together with a scale unit (not shown). For example, the position sensor 65 is fixedly provided in front of the cylinder member 15, and the scale portion is provided on the piston rod 21 and extends in the axial direction thereof. And the position sensor 65 detects the position of the plunger 5 indirectly by detecting the position of the scale part which moves with the movement of the piston rod 21. The position sensor 65 or the control device 153 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 15h and a pressure sensor for detecting the pressure of the rod side chamber 15r are provided, and the control device 153 determines whether the plunger 5 is based on the detection values of these pressure sensors. 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 35 is provided, and the control device 153 can determine the completion of filling of the accumulator 35 based on the detected value.

(Operation of injection device)
FIG. 3 is a diagram for explaining the operation of the injection apparatus 1. In FIG. 3, the horizontal axis represents time. A solid line Lv indicates a change in injection speed, and a solid line Lp indicates a change in injection pressure. In the graph in which the solid lines Lv and Lp are drawn, the vertical axis indicates the magnitude of the injection speed and the injection pressure. Further, below the graph, operations of the injection piston 17 of the injection cylinder 9, the drive motor 41, the attaching / detaching portion 45, the servo valve 39, the pump motor 33, and the accumulator 35 are shown. In the lower part of FIG. 3, the load of the drive motor 41 is shown.

  “ON / OFF” of the servo valve 39 indicates a state in which the opening degree is controlled / a state in which the opening degree is opened or closed without being controlled. Further, “filling” of the accumulator 35 indicates a state in which the accumulator 35 can be filled (the filling does not have to be performed over the entire range “filled”).

  In general, the injection device 1 performs low-speed injection, high-speed injection, and pressure increase (pressure increase) in order. That is, in the initial stage of injection, the injection device 1 advances the plunger 5 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 5 is advanced at a relatively high speed. Thereafter, the injection device 1 increases the pressure of the molten metal in the cavity by the force in the direction in which the plunger 5 advances in order to eliminate sink marks in the molded product. Specifically, it is as follows.

(Low speed injection: t0 to t1)
Immediately before the start of the low speed injection, the injection device 1 is in the state shown in FIGS. That is, the injection piston 17 of the injection cylinder 9 and the screw shaft 51 of the drive device 13 are located at an initial position such as a backward limit. In this initial position, the base portion 55 of the attaching / detaching portion 45 is in contact with the contacted portion 27b of the coupling 23, and the hook 57 of the attaching / detaching portion 45 can be engaged with the contacted portion 27b. However, the engagement is not necessarily performed, and the engagement is released (OFF) in this embodiment. Further, the drive motor 41 is stopped. The pump electric motor 33 is stopped if the accumulator 35 is completely filled, and is driven if the filling is not completed. For example, the hydraulic circuit 37 prohibits the inflow and outflow of the hydraulic fluid in the injection cylinder 9.

  The control device 153 drives the drive motor 41 when a predetermined low-speed injection start condition is satisfied, for example, the mold clamping of the fixed mold 101 and the movable mold 103 is completed and the molten metal is supplied to the sleeve 3. The driving force is transmitted to the contacted portion 27b through the screw mechanism 43 and the base portion 55. Thereby, the plunger 5 and the piston rod 21 move forward. That is, low speed injection is performed by the driving force of the driving device 13.

  The control device 153 controls the hydraulic circuit 37 so that the hydraulic fluid is appropriately discharged from the rod side chamber 15r and supplied to the head side chamber 15h as the injection piston 17 moves forward. .

  For example, the hydraulic circuit 37 discharges the hydraulic fluid discharged from the rod side chamber 15r to the tank 29 or returns to the head side chamber 15h via a run-around circuit (not shown). During the low speed injection, the servo valve 39 is fully opened, for example. Even when the run-around circuit is used, the head side chamber 15h has a larger pressure receiving area than the rod side chamber 15r, and therefore it is necessary to supply hydraulic fluid to the head side chamber 15h.

  Further, for example, the hydraulic circuit 37 allows the flow of hydraulic fluid from the tank 29 to the head side chamber 15h and replenishes the hydraulic fluid to the head side chamber 15h. The filling of the accumulator 35 may be terminated before the low-speed injection, and the hydraulic fluid may be supplied from the pump 31 to the head side chamber 15h. Alternatively, the hydraulic fluid may be supplied to the head side chamber 15h from an assist accumulator (not shown). When the hydraulic fluid is replenished from the pump 31 or the accumulator, the hydraulic fluid may be replenished to such an extent that no negative pressure is generated in the head side chamber 15h. It can be said that the hydraulic fluid may be replenished so as to assist the drive of the plunger 5 by the drive device 13 (for example, to generate several tens of% of the driving force for driving the plunger 5).

  The speed of the plunger 5 is controlled by adjusting the rotational speed of the drive motor 41. Specifically, the control device 153 feedback-controls the rotational speed of the drive motor 41 based on the speed of the plunger 5 detected by the position sensor 65.

  The filling of the accumulator 35 is terminated when the pump motor 33 is stopped (OFF) when a detection value of a pressure sensor (not shown) that detects the pressure of the accumulator 35 reaches a predetermined filling completion pressure. The number of revolutions of the pump motor 33 is appropriately set so that the filling of the accumulator 35 is completed at an appropriate time after the charging start of the accumulator 35 described later until the low-speed injection ends.

  In addition, although FIG. 3 illustrates the case where the low-speed injection is performed in a state where the attachment / detachment unit 45 is turned off (disengaged), the attachment / detachment unit 45 may be turned on. In this case, for example, when multistage control including deceleration is performed, it is possible to prevent the plunger 5 from moving away from the base portion 55 due to inertial force.

(High-speed injection: t1 to t2)
The control device 153 controls the hydraulic circuit 37 so that the working fluid is supplied from the accumulator 35 to the head side chamber 15h when the position of the plunger 5 based on the detection value of the position sensor 65 reaches a predetermined high speed switching position. Further, the control device 153 adjusts the servo valve 39 to an appropriate opening degree. Further, the control device 153 continues turning OFF the attachment / detachment unit 45 from the low-speed injection, or turns OFF the attachment / detachment unit 45 that was ON in the low-speed injection.

  Thereby, the injection piston 17, the piston rod 21, and the plunger 5 advance at a relatively high speed. At this time, since the engagement of the detachable portion 45 is released, the plunger 5 or the like moves forward leaving the detachable portion 45 and the screw shaft 51 moving at a relatively low speed. Therefore, the drive device 13 does not become a load that prevents the plunger 5 or the like from moving forward. Then, the molten metal of the sleeve 3 is injected into the cavity 105 at a high speed.

  In addition, when the plunger 5 is driven by the injection cylinder 9, the load of the drive motor 41 of the drive device 13 is lower than that during low-speed injection.

  The speed of the plunger 5 is controlled by adjusting the opening degree of the servo valve 39. Note that the control device 153 may feedback control the opening degree of the servo valve 39 based on the speed of the plunger 5 detected by the position sensor 65.

(Decelerated injection: t2 to t3)
When the molten metal is filled to some extent in the cavity 105, the plunger 5 receives a reaction force from the filled molten metal and decelerates, while the injection pressure increases rapidly. 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 such as reducing the opening degree of the servo valve 39 when a predetermined deceleration start condition is satisfied, such as when the plunger 5 reaches a predetermined deceleration position, is performed. May be made.

(Pressure increase: t3 to t4)
When a predetermined pressure increase start condition is satisfied, the control device 153 controls the hydraulic pressure circuit 37 to start the pressure increase process. The pressure increase start condition is, for example, a predetermined injection pressure based on a detection value of a pressure sensor (not shown) that detects the pressure of the head side chamber 15h (and a pressure sensor (not shown) that detects the pressure of the rod side chamber 15r as necessary). Or the detection position of the plunger 5 detected by the position sensor 65 has reached a predetermined position.

  The hydraulic circuit 37 allows the hydraulic fluid to be discharged from the accumulator 35 to the rear chamber 15e, allows the hydraulic fluid to be discharged from the front chamber 15f to the tank 29, and the hydraulic fluid from the head side chamber 15h to start the pressure increase. The discharge of the hydraulic fluid from the rod side chamber 15r to the tank 29 is permitted. Thereby, the pressure in the head side chamber 15h is pressurized by the pressure increasing piston 19, the injection pressure rises, and the injection pressure reaches the final pressure. Further, the injection speed becomes 0 when the cavity 105 is completely filled with the molten metal.

(Holding pressure: t4 to t6)
The control device 153 maintains the state where the injection pressure is the final pressure. During this time, the molten metal is cooled and solidified. When the molten metal solidifies, the control device 153 controls the hydraulic circuit 37 so as to stop the supply of the hydraulic pressure from the accumulator 35 to the rear chamber 15e, and the pressure holding ends.

  Note that the control device 153 determines whether or not the molten metal has solidified as appropriate. For example, the control device determines whether or not the molten metal has solidified based on whether or not a predetermined time has passed since a predetermined time such as the time when the final pressure is obtained.

(Attachment / detachment part: t5)
The pressure increase is started and the speed of the plunger 5 is decreased, and further, the pressure holding is started and the plunger 5 is stopped, so that the attaching / detaching portion 45 (base portion 55) continuously driven from the low-speed injection by the driving device 13. Catches up with the contacted portion 27b. In other words, the detachable portion 45 is in a state that can be engaged with the contacted portion 27b. The time when the detachable portion 45 reaches the abutted portion 27b is preferably before the pressure holding is completed.

  The control device 153 stops the drive motor 41 when detecting the arrival of the attaching / detaching portion 45 to the contacted portion 27b based on the detection values of the position sensor 65 and the encoder 47. Note that the position of the attaching / detaching unit 45 may be detected by providing a position sensor (linear encoder) similar to the position sensor 65.

  The speed of the attachment / detachment unit 45 from the start of high-speed injection until the attachment / detachment unit 45 reaches the contacted portion 27b may be equal to or different from the speed at the time of low-speed injection. Further, deceleration control may be appropriately performed so that the base 55 does not give an impact to the plunger 5.

(Extrusion follow-up: t7 to t9)
After completion of the pressure holding, the control device 153 causes the mold clamping device (not shown) to open the mold and pushes out the molded product from the fixed mold 101 by the extrusion device (not shown). At this time, the control device 153 controls these so that the injection cylinder 9 and / or the drive device 13 generate drive force for pushing out the biscuits by the plunger 5. FIG. 3 illustrates a case in which the plunger 5 is driven by the driving device 13 and the injection cylinder 9 is also driven in the initial stage of extrusion follow-up (t7 to t8).

(Plunger retraction: t10 to t11)
The control device 153 is configured to operate at an appropriate time after the attachment / detachment portion 45 reaches the abutted portion 27b (after t5), preferably after completion of pressure holding (after t6), and more preferably at the start of extrusion follow-up. At (t7), the detachable portion 45 is turned on (engaged). Then, when the extrusion follow-up is completed, the control device 153 drives the drive motor 41 in the direction in which the attachment / detachment unit 45 is retracted. Thereby, the plunger 5 moves backward.

  While the plunger 5 is retracted by the driving device 13, for example, the injection cylinder 9 is in a state where no driving force is generated, and is returned to the initial state by the driving force of the driving device 13. For example, the hydraulic circuit 37 permits the replenishment of the working fluid from the tank 29 to the rod side chamber 15r, prohibits the discharge of the working fluid from the head side chamber 15h, allows the replenishment of the working fluid from the tank 29 to the front side chamber 15f, And discharge | emission of the hydraulic fluid from the rear side chamber 15e to the tank 29 is performed. Thereby, the injection piston 17 and the pressure-increasing piston 19 are retracted as the plunger 5 is retracted. When the pressure-increasing piston 19 reaches the retreat limit, the hydraulic fluid is allowed to be discharged from the head side chamber 15h to the tank 29. The hydraulic fluid discharged from the head side chamber 15h may be returned to the rod side chamber 15r.

  As a result of the retraction of the plunger 5 as described above, the plunger 5, the piston rod 21 and the screw shaft 51 are returned to the initial positions shown in FIGS. That is, preparation for the next molding cycle (injection cycle) is completed.

(Accumulator filling: t9 to t11 to t1)
The filling of the accumulator 35 may be performed at an appropriate time except for high-speed injection in which the accumulator 35 is discharged, pressure increase and holding pressure, and extrusion follow-up in which the accumulator 35 may be discharged.

  For example, when the extrusion follow-up is completed (t9), the control device 153 starts driving the pump motor 33 and starts filling the accumulator 35. The filling completion time of the accumulator 35 is set to an appropriate time until the end of the low speed injection as described above.

  The operation of the injection device 1 described above, that is, the operation from the start of low-speed injection (t0) to the return to the initial state by the completion of retraction of the plunger 5 (t11) constitutes an injection cycle. As already described, the length of the threaded portion 51a is defined by the range of relative movement of the nut 53 with respect to the screw shaft 51 in this injection cycle.

  As described above, in the present embodiment, the injection apparatus 1 includes the injection cylinder 9 having the sleeve 3 that communicates with the cavity 105, the plunger 5 that pushes the molten metal in the sleeve 3 into the cavity 105, and the piston rod 21 that is connected to the plunger 5. And a driving device 13.

  The driving device 13 rotates the screw shaft 51 parallel to the piston rod 21, the nut 53 screwed to the screw shaft 51, and the nut 53, thereby moving the screw shaft 51 in a direction parallel to the piston rod 21. A drive motor 41 that generates a force, and a base 55 that moves together with the screw shaft 51 and is restricted from moving forward relative to the piston rod 21 and allowed to move backward relative to the piston rod 21. . The screw shaft 51 has a threaded portion 51a that is a range in which the nut 53 moves relative to the screw shaft 51 in the injection cycle (t0 to t11). The screw part 51a and the nut 53 are located behind the base part 55 over the injection cycle.

  Therefore, as already described, the screwing portion 51a, the nut 53, and the like can be arranged rearward from the sleeve 3. As a result, the molten metal or lubricant supplied to the sleeve 3 is suppressed from scattering to the screw mechanism 43 and the like, and consequently, the performance deterioration or the life shortening of the driving device 13 is suppressed.

  Unlike this embodiment, by making the plunger or piston rod longer, the connecting position (position of the attaching / detaching portion) between the piston rod and the drive device is set to a position away from the sleeve, and as a result, the drive device is moved further rearward. It is possible to arrange. However, in this case, the plunger or the piston rod loses compatibility with that in the conventional hydraulic injection device in which the plunger is driven only by the hydraulic device. Further, the arrangement position of the cylinder member is also behind the conventional hydraulic injection device. As a result, for example, it becomes difficult to hybridize an existing hydraulic injection device. In addition, the length of the injection device is also increased due to the cylinder member being positioned rearward.

  However, in the present embodiment, since the rear arrangement of the screwing portion 51a and the like is realized by devising the configuration of the drive device 13 as described above, the configuration of the plunger 5 and the configuration and arrangement of the injection cylinder 9 are arranged. The position may be the same as in a conventional hydraulic injection device. As a result, for example, it is easy to hybridize an existing hydraulic injection device. Further, for example, the cylinder member 15 can be fixed to the injection frame 159 in the same manner as a conventional hydraulic injection device. An increase in the length of the injection device due to the cylinder member 15 being positioned rearward is also suppressed.

  Moreover, in this embodiment, the structure which rotates the nut 53 and moves the screw shaft 51 to the front-back direction is employ | adopted. The screw shaft 51 is located in front of the screwing part 51a, and includes a connecting part 51b to which the base 55 is fixed, and an intermediate part 51c located between the connecting part 51b and the screwing part 51a. Yes.

  Therefore, the screwing portion 51 a and the nut 53 can be arranged behind the base portion 55 by a simple method of providing the intermediate portion 51 c on the screw shaft 51.

  In the above first embodiment, the nut 53 is an example of the rotating member of the present invention, the screw shaft 51 is an example of the moving member of the present invention, and the base 55 is an example of the regulated member of the present invention. is there.

<Second Embodiment>
FIG. 4 is a top view (partly including a cross-sectional view) schematically showing a configuration of a main part of the injection apparatus 201 according to the second embodiment, and corresponds to FIG. 2 of the first embodiment. It is. Moreover, about the structure which only differs in dimension from 1st Embodiment, the code | symbol same as the structure of 1st Embodiment may be attached | subjected.

  In the first embodiment, the driving device 13 is configured to rotate the nut 53 and move the screw shaft 51 in the front-rear direction. On the other hand, the drive device 213 of the second embodiment is configured to rotate the screw shaft 251 and move the nut 253 in the front-rear direction. Specifically, it is as follows.

  The driving device 213 includes a driving motor 241, a transmission mechanism 271 that transmits the driving force of the driving motor 241, a screw mechanism 243 that transmits the driving force transmitted from the transmission mechanism 271, and a driving force transmitted from the screw mechanism 243. And an attaching / detaching portion 45 driven in the front-rear direction. The driving device 213 includes a guide shaft 272 interposed between the screw mechanism 243 and the attaching / detaching portion 45. The drive device 213 includes two combinations of the drive motor 41, the transmission mechanism 271, the screw mechanism 243, the attaching / detaching portion 45, and the guide shaft 272, for example, symmetrically.

  Unlike the first embodiment, the drive motor 241 is not configured integrally with the screw mechanism 243. The drive motor 241 has an output shaft 241a fixed to the rotor, for example, like a general motor. For example, the drive motor 241 is arranged with the output shaft 241a facing rearward.

  The transmission mechanism 271 includes, for example, a pulley / belt mechanism, and includes a first pulley 273 fixed to the output shaft 241a, a second pulley 274 fixed to the screw shaft 251, a first pulley 273, and a second pulley. And a belt 275 suspended on a pulley 274.

  Therefore, when the output shaft 241a of the drive motor 241 is rotated, the rotation is transmitted to the screw shaft 251 via the transmission mechanism 271 and the screw shaft 251 is rotated.

  The screw shaft 251 and the second pulley 274 are fixed coaxially via a transmission shaft 277 that is restricted from moving in the axial direction by an appropriate bearing and allowed to rotate about the axis, for example.

  The screw mechanism 243 is configured by, for example, a ball screw mechanism, and includes a screw shaft 251 and a nut 253 that is screwed onto the screw shaft 251 via a ball (not shown).

  The screw shaft 251 is disposed in parallel to the piston rod 21. Further, the screw shaft 251 is restricted from moving in the axial direction by being fixed to the above-described transmission shaft 277 and is allowed to rotate about the axis. On the other hand, the nut 253 is allowed to move in the axial direction by being fixed to the guide shaft 272, and the rotation about the axis is restricted. Therefore, when the screw shaft 251 is rotated, the nut 253 moves in a direction parallel to the piston rod 21.

  The guide shaft 272 extends in a direction parallel to the piston rod 21, and one end side is fixed to the nut 253 and the other end side is fixed to the base portion 55. Therefore, when the nut 253 moves in the front-rear direction, the base 55 also moves in the front-rear direction.

  The guide shaft 272 has an appropriate length with respect to the threaded portion 251a of the screw shaft 251 (for example, a length equal to or longer than the length of the threaded portion 251a). Accordingly, even when the nut 253 is positioned at the retreat limit of the injection cycle, the base portion 55 (the regulated member) is positioned ahead of the screwing portion 251a. That is, the screwing portion 251a and the nut 253 are located behind the base portion 55 over the injection cycle.

  The definition of the screwing portion 251a is the same as that of the first embodiment, and is defined by the range in which the nut 253 moves relative to the screw shaft 251 in the injection cycle. In addition, the determination as to whether or not the screwing portion 251a (the whole) or the like is positioned behind the base portion 55 also restricts the forward movement relative to the piston rod 21 in the base portion 55, as in the first embodiment. Suppose that it is made based on the position of the part which contributes to (the surface which contacts the cover 227 from the rear in this embodiment). In determining whether or not the nut 253 is positioned behind the base portion 55, the size of the nut 253 is determined based on a portion that can be screwed to the screw shaft 251. For example, even if the guide shaft 272 and the nut 253 are integrated, the range where the guide shaft 272 and the screw shaft 251 are screwed together can be specified as the nut 253.

  When the nut 253 is positioned at the retreat limit of the injection cycle, the guide shaft 272 is positioned in the axial direction of the nut 253 from the length of the threaded portion 251a so that the base 55 is positioned forward of the threaded portion 251a. It is only necessary to have a length obtained by adding the length obtained by subtracting the thickness, the length necessary for fixing the guide shaft 272 and the nut 253, and the length necessary for fixing the guide shaft 272 and the base 55.

  For example, the guide shaft 272 is formed in a hollow shape that accommodates the screw shaft 251. For example, the hollow shape has a circular cross section and a constant diameter except for a portion fixed to the nut 253. For example, when the nut 253 is positioned at the retreat limit of the injection cycle, the guide shaft 272 has a length that can cover the entire front of the nut 253 in the screwing portion 251a. More preferably, the guide shaft 272 covers the entire front of the screw shaft 251 (which may include a portion other than the screwing portion 251a) of the screw shaft 251 when the nut 253 is positioned at the retreat limit of the injection cycle. Yes. In this case, more preferably, the tip of the guide shaft 272 is closed.

  The guide shaft 272 and the nut 253 are fixed by, for example, increasing the diameter of the rear end of the guide shaft 272 and fitting the nut 253 to the expanded diameter portion and preventing the nut 253 from coming off. The inner surface of the portion of the guide shaft 272 to which the nut 253 is fitted is, for example, a polygon corresponding to the shape of the outer peripheral surface of the nut 253.

  The guide shaft 272 and the base portion 55 are fixed by, for example, inserting the guide shaft 272 into the base portion 55 and fixing them with screws (not shown). Note that the fixing of the guide shaft 272 and the base portion 55 contributes to the restriction of rotation around the axis of the guide shaft 272 (and consequently the restriction of rotation of the nut 253).

  For example, the guide shaft 272 is slidably inserted into a bush 163 provided in the injection frame 161. As a result, the load of the guide shaft 272 and unnecessary moment generated in the guide shaft 272 are supported by the injection frame 161, and an unnecessary force is prevented from being applied to the plunger 5 and the like.

  The coupling 223 of the injection device 201 includes, for example, a spacer 25 interposed between the plunger 5 and the piston rod 21 and a cover 227 that covers these, similarly to the coupling 23 of the first embodiment. Yes.

  However, unlike the cover 27 of the first embodiment, the cover 227 has a contacted portion 227b in the middle in the front-rear direction, not at the rear end. The rear portion of the cover 227 with respect to the contacted portion 227 b is fitted to the base portion 55. Therefore, the piston rod 21 is shortened by the length that the cover 227 is inserted into the base 55, and as a result, the rear end of the cylinder member 15 is positioned forward.

  Also in the second embodiment, the rear end of the drive device 213 (the rear end of the output shaft 241a and the rear end of the transmission shaft 277) substantially coincides with the rear end of the injection cylinder 9 as in the first embodiment. ing. Accordingly, the length of the injection device 201 is suppressed, and the drive motor 241 and the like are arranged as far as possible.

  The operation of the injection device 201 of the second embodiment is substantially the same as the operation of the injection device 1 of the first embodiment. However, as understood from the above description, when the plunger 5 is driven by the driving force of the drive motor 241, the nut 253 rotates and the screw shaft 251 moves in the front-rear direction.

  Also in the second embodiment described above, since the screwing portion 251a and the nut 253 are disposed behind the base portion 55 (the regulated member) over the injection cycle, the first embodiment is employed. The same effect as the form is produced. That is, the driving device 213 can be arranged away from the sleeve 3 in the axial direction, and the operating environment of the driving device 213 can be improved.

  Moreover, in this embodiment, the structure which rotates the screw shaft 251 and moves the nut 253 to the front-back direction is employ | adopted. The drive device 213 has a guide shaft 272 that extends in a direction parallel to the piston rod 21, one end of which is fixed to the nut 253 and the other end is fixed to the base 55.

  Accordingly, since the base portion 55 and the like move along the screw shaft 251, stable operation is expected. Further, as the screw shaft 251, a general screw shaft having no intermediate portion can be used.

  In the present embodiment, the guide shaft 272 is formed in a hollow shape that accommodates the screw shaft 251.

  Therefore, the guide shaft 272 not only enables the configuration from the drive motor 241 to the screw mechanism 243 to be arranged rearward, but also plays a role of directly protecting the screw shaft 251 from the molten metal and the release agent. As a result, the operating environment of the driving device 213 is dramatically improved.

  In the second embodiment described above, the screw shaft 251 is an example of the rotating member of the present invention, the nut 253 is an example of the moving member of the present invention, and the base 55 is an example of the regulated member of the present invention. The guide shaft 272 is an example of the relay member of the present invention.

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

  The above-described embodiments may be appropriately combined. For example, the driving device 13 of the first embodiment and the coupling 223 of the second embodiment may be combined. Similarly, the drive device 213 of the second embodiment and the coupling 23 of the first embodiment may be combined. Further, for example, the screw mechanism 43 of the first embodiment may be combined with the drive motor 241 and the transmission mechanism 271 of the second embodiment. Specifically, the nut 53 of the first embodiment and the second pulley 274 of the second embodiment may be fixed. Similarly, the screw mechanism 243 of the second embodiment and the drive motor 41 of the first embodiment may be combined. Specifically, the rotor of the drive motor 41 may be fixed to the rear portion of the screw shaft 251.

  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 molding machine may not have an injection frame. The hydraulic fluid is not limited to oil and may be water, for example.

  When a transmission mechanism that transmits a driving force from the electric motor of the driving device to the screw mechanism is provided, the transmission mechanism is not limited to the pulley belt mechanism, and may be a gear mechanism, for example.

  The drive and injection cylinder may be used alone or together as appropriate in the injection cycle.

  For example, the drive device may not be used for plunger retraction and extrusion tracking. Specifically, as disclosed in Patent Document 1, the driving device is stopped when switching from the low speed injection to the high speed injection, and the backward movement of the plunger and the follow-up of the plunger may be performed only by the cylinder device. Good.

  In this case, it is only necessary that the driving device can be driven with a low-speed injection stroke, and the screwing portion can be shortened. As a result, without increasing the length of the injection device, the intermediate portion or the relay member (guide shaft) can be lengthened, and the screwing portion, the nut, the drive motor, and the like can be arranged further rearward.

  Further, for example, contrary to the above, the driving device may be used for pressure increase and / or pressure holding so as to assist the injection cylinder. Such cooperation between the driving device and the cylinder device may be performed only in a part of one process.

  As described above, the drive device does not necessarily have to be subjected to the retraction of the plunger. Therefore, the injection device only needs to be able to restrict the relative advancement of the screw shaft with respect to the piston rod and to allow the relative backward movement of the screw shaft with respect to the piston rod. That is, in the injection device, the configuration including the regulated member (base portion 55 in the embodiment) does not have to be a configuration (detachable portion) capable of regulating the relative retreat of the screw shaft with respect to the plunger. For example, in the embodiment, the hook 57 and the actuator 59 can be omitted.

  Further, in the case where the detachable portion is provided, it is sufficient that the detachable portion can release the connection so as to allow at least the driven portion to move backward relative to the piston rod. Further, the connection may be released so as to allow both the backward movement and the backward movement. For example, the attaching / detaching portion includes an engaging member (a regulated member) that is movable between a position where the piston rod is engaged with both the forward and backward directions and a position retracted from the engaging position. And an actuator for driving the engaging member.

  In addition, in the case where the detachable portion is provided, the regulated member may not be a member that comes into contact with the piston rod or a member fixed to the piston rod from the rear. For example, the regulated member is a front-rear direction of the screw shaft with respect to the piston rod of the screw shaft by holding the piston rod or a predetermined member fixed to the piston rod from the side or adsorbing the predetermined member from the side by the frictional force alone. The relative movement may be restricted. In addition, the relative movement between the screw shaft and the piston rod may be appropriately regulated or allowed. For example, various aspects disclosed in Patent Document 1 may be applied.

  The hydraulic device can be appropriately configured, and the connection and sharing of various flow paths and the arrangement of various valves can be appropriately changed. For example, in the embodiment, the servo valve 39 constituting the meter-out circuit is provided, but a servo valve constituting the meter-in circuit may be provided instead of or in addition to the servo valve 39.

  In the screw shaft having the intermediate portion described in the first embodiment, the connecting portion, the intermediate portion, and the screwing portion do not need to be formed integrally. For example, the screwing portion and the intermediate portion may be configured by separate members and connected to each other by a coupling or the like. Further, the relay member (guide shaft) described in the second embodiment may be formed integrally with the regulated member (part or all) and / or the nut.

  The length of the intermediate portion may be set in a longer range than the range of a length exceeding 1/5 or 1/3 of the stroke of the injection cylinder exemplified in the embodiment. For example, the length of the intermediate portion may be equal to or greater than half of the stroke of the injection cylinder, or equal to or greater than the stroke of the injection cylinder. In this case, protection of the screwed portion of the screw mechanism and the like is further ensured. In particular, when the intermediate portion has a length equal to or longer than the stroke of the injection cylinder, even when the screw shaft advances, the screwing portion advances only to the vicinity of the front end (injection frame) of the cylinder member. Protection of joints etc. is ensured. Similarly, the relay member (guide shaft) may be set in a longer range than the range of a length equal to or longer than the length of the threaded portion illustrated in the embodiment.

  In addition, the upper limit of the length of the intermediate part and the relay member may be appropriately set as long as the injection device is not so long as to be unrealistic. For example, the upper limit of the length of the intermediate part and the relay member is about twice the stroke of the injection cylinder.

  The rear end of the drive device (for example, the rear end of the screw shaft located at the retreat limit of the injection cycle in the first embodiment, the front end of the output shaft in the second embodiment, etc.) coincides with the rear end of the injection cylinder. It does not have to be. That is, the rear end of the drive device may be positioned forward or rearward of the rear end of the injection cylinder. However, as described in the embodiment, from the viewpoint of disposing the screw mechanism and the drive motor behind while suppressing an increase in the length of the injection device, the rear end of the drive device is within a predetermined range from the rear end of the injection cylinder. It is preferable to be within the range.

  For example, if the thickness of the injection frame, the thickness of the rod cover, and the thickness of the head cover are estimated to be 1/10 or more of the stroke of the injection cylinder, in the first embodiment, after the screw shaft positioned at the backward limit of the injection cycle, If the end is less than 1/10 of the stroke from the rear end of the injection cylinder, the length of the intermediate portion is preferably more than 1/5 of the stroke. Similarly, also in the second embodiment, if the rear end of the drive device is less than 1/10 of the stroke of the injection cylinder from the rear end of the injection cylinder, the stroke of the above-described stroke is between the regulated member and the screwed portion. A distance exceeding 1/5 is easily secured, which is preferable.

  In the second embodiment, the relay member that connects the nut and the regulated member covers the screw shaft, but the relay member may not cover the screw shaft. For example, the relay member may be a solid shaft member that extends parallel to the screw shaft.

  DESCRIPTION OF SYMBOLS 1 ... Injection apparatus, 3 ... Sleeve, 5 ... Plunger, 9 ... Injection cylinder, 13 ... Drive apparatus, 51 ... Screw shaft, 51a ... Screwing part, 51b ... Connection part, 51c ... Intermediate part, 53 ... Nut, 41 ... Electric motor, 105 ... cavity.

Claims (4)

A sleeve leading to the cavity;
A plunger that pushes the material in the sleeve into the cavity;
An injection cylinder having a piston rod coupled to the plunger;
A driving device;
Have
The driving device includes:
A screw shaft parallel to the piston rod;
A nut screwed onto the screw shaft;
An electric motor that generates a driving force that rotates a rotating member that is one of the screw shaft and the nut, thereby moving a moving member that is the other of the screw shaft and the nut in a direction parallel to the piston rod;
A regulated member that moves together with the moving member, is restricted relative to the piston rod, and is allowed to move backward relative to the piston rod;
The screw shaft has a threaded portion that is a range in which the nut moves relative to the screw shaft in an injection cycle,
The threaded portion and the nut, the injection apparatus in its entirety is positioned behind the object to be restricting member over the injection cycle. The rotating member is the screw shaft;
The moving member is the nut;
The injection device according to claim 1, wherein the driving device includes a relay member extending in a direction parallel to the piston rod, one end side being fixed to the nut and the other end side being fixed to the regulated member. The rotating member is the nut;
The moving member is the screw shaft;
The screw shaft is
A connecting portion that is positioned in front of the screwing portion and to which the regulated member is fixed;
An intermediate portion located between the connecting portion and the screwing portion ,
The injection device according to claim 1, wherein the drive device has two screw mechanisms including the nut and the screw shaft in parallel with the injection cylinder . The injection device according to any one of claims 1 to 3,
A mold clamping device;
A molding apparatus having:

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