JP2019150848A - Injection device and molding machine - Google Patents

Abstract

To provide an injection device in which the rotation around the axis of a plunger can be suitably regulated.SOLUTION: An injection device 9 moving a plunger 23 slidable inside a sleeve 21 leading to the inside of a mold 101 forward and backward, comprises a screw mechanism 33, an electric motor 31, a pair of guide faces 51b, and a guided part 53. A nut 41 of the screw mechanism 33 can be connected coaxially to the plunger 23. A screw shaft 39 of the screw mechanism 33 is regulated in movement in its axial direction. The electric motor 31 generates driving force rotating the screw shaft 39. The pair of guide faces 51b face in a direction confronted each other around the axis of the screw mechanism 33, and have a length in the axial direction of the screw mechanism 33. The guided part 53 is regulated in movement in the axial direction of the screw mechanism 33 to the nut 41 and around the axis of the screw mechanism 33, and is inserted into a space between the pair of guide faces 51b from the side of the screw mechanism 33.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to an injection apparatus and a molding machine. The molding machine is, for example, a die casting machine or an injection molding machine.

  2. Description of the Related Art As an injection device that pushes a molding material in a sleeve that communicates with a mold into the mold by using a plunger, an apparatus that drives the plunger with a screw mechanism is known (for example, Patent Documents 1 and 2). The screw mechanism converts the rotation of the electric motor into a translational motion and transmits it to the plunger.

  Specifically, the screw mechanism includes a screw shaft and a nut that is screwed onto the screw shaft. The translation element, which is one of the screw shaft and the nut, is coaxially connected to the plunger, and is allowed to move in the axial direction and is restricted from rotating around the shaft. The rotation element that is the other of the screw shaft and the nut is restricted from moving in the axial direction and is allowed to rotate about the axis. Then, when the rotating element is rotated around the axis by the electric motor, the translation element moves in the axial direction, and thereby the plunger moves forward and backward in the sleeve relative to the mold.

  In Patent Document 1, a guide bar that extends in parallel to the screw mechanism and a slider that is fixed to the translation element and through which the guide bar is inserted are provided. This restricts the rotation of the translation element about its axis.

  Moreover, in patent document 2, rotation of the translation element around its axis is regulated by a linear guide. The linear guide includes a rail that extends in parallel to the screw mechanism, and a slider that is fixed to the translation element and has a concave groove that is guided by the rail.

JP 2014-79765 A JP 2014-87843 A

  It is preferable to provide an injection apparatus and a molding machine that can suitably regulate the rotation of the translation element about its axis in the screw mechanism that drives the plunger.

  An injection device according to an aspect of the present disclosure is an injection device that moves a plunger slidable in a sleeve communicating with a mold, and includes a screw shaft and a nut that is screwed to the screw shaft. A screw mechanism in which one of these translation elements can be coaxially coupled to the plunger and the movement of the other rotation element in its axial direction is restricted, and the rotation element is rotated. An electric motor for generating a driving force, a pair of guide surfaces facing each other around an axis of the screw mechanism, and having a length in the axial direction of the screw mechanism, and the translation element A movement of the screw mechanism in the axial direction and around the axis of the screw mechanism is restricted, and a guided portion is inserted between the pair of guide surfaces from the screw mechanism side.

  In one example, the guided portion is restricted from moving in the axial direction of the screw mechanism and the axis of the screw mechanism with respect to the translation element, and an axis having a direction intersecting the axial direction of the screw mechanism as an axial direction. And a shaft that is rotatably supported about the axis of the shaft relative to the translation element, and has a diameter smaller than the distance between the pair of guide surfaces, and between the pair of guide surfaces And a rotating body located in the position.

  In one example, the injection device further includes an extending member extending in the axial direction of the screw mechanism, and a guide groove extending in the axial direction of the screw mechanism is formed in the extending member, and the guide groove The pair of guide surfaces are constituted by the pair of inner wall surfaces.

  In one example, the extending member is a hollow member that covers the outer periphery of the screw mechanism.

  In one example, the guide groove penetrates the extending member from the inside to the outside, and a hose extending from the outside of the extending member to the translation element via the guide groove is provided, The movement range of the guided portion and the movement range of the hose corresponding to the movement range from the backward limit to the forward limit of the translation element partially overlap each other.

  In one example, the axial direction of the screw mechanism is a horizontal direction, and the guide groove passing through the extending member from the inside to the outside is provided only under the extending member.

  In one example, the extending member includes a hollow member integrally formed in a hollow shape covering the screw mechanism, and the hollow member has one end fixed to the injection frame and the other end receiving the rotating element. It is fixed to a member that is supported so as not to move in the axial direction.

  In one example, the injection device further includes an injection rod that is interposed between and connected to the plunger and the translation element, the translation element is a nut, and the rotation element is a screw shaft. The injection rod has a cylindrical portion that covers a portion of the screw shaft that is closer to the plunger than the nut, and the hollow member is movable in the axial direction of the cylindrical portion. I support it.

  The molding machine which concerns on 1 aspect of this indication has said injection apparatus, the mold clamping apparatus which clamps the said metal mold | die, and the extrusion apparatus which extrudes a molded article from the said metal mold | die.

  According to said structure, rotation around the axis | shaft of a translation element can be controlled suitably.

The schematic diagram which shows the structure of the die-casting machine which has the injection device which concerns on embodiment of this indication. Sectional drawing which shows the structure of the injection apparatus of FIG. The bottom view which shows a part of injection apparatus of FIG.

(Overall configuration of die casting machine)
FIG. 1 is a side view partially including a cross-sectional view illustrating a configuration of a main part of a die casting machine 1 according to an embodiment of the present disclosure. In addition, the vertical direction of the paper surface is a vertical direction, and the horizontal direction of the paper surface and the through direction of the paper surface are horizontal directions.

  The die casting machine 1 injects an uncured metal material into a mold 101 (a space such as a cavity Ca; the same applies hereinafter), and solidifies the metal material in the mold 101, thereby producing a die cast product (molded product). Is to be manufactured. The uncured state is, for example, a liquid or solid-liquid coexistence state. The solid-liquid coexistence state is a semi-solid state where solidification has progressed from a liquid state, or a semi-molten state where melting has progressed from a solid state. The metal is, for example, aluminum or an aluminum alloy. In the following, molten metal (liquid metal material) may be taken as an example of the uncured metal material.

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

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

  The machine body 3 includes, for example, a mold clamping device 7 that opens and closes and molds the mold 101, an injection device 9 that injects molten metal into the mold 101, and a die-cast product that is a fixed mold 103 or a movable mold 105 ( In FIG. 1, it has the extrusion apparatus 11 extruded from the moving metal mold | die 105). In the machine body 3, the configuration other than the injection device 9 (for example, the configuration of the mold clamping device 7 and the extrusion device 11) may be the same as various known configurations.

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

  The control unit 5 may be similar to various known configurations. For example, the control unit 5 includes a control panel (not shown) having a power supply circuit, a control circuit, and the like, and an operation unit (reference numeral omitted) as a user interface. A part of the control panel and the operation unit constitutes a control device that controls each unit. The operation unit includes, for example, a display device that displays an image and an input device that receives an input operation of an operator.

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

  The sleeve 21 is, for example, a cylindrical member connected to the fixed mold 103, and a supply port 21 a for receiving the molten metal into the sleeve 21 is opened on the upper surface. The plunger 23 has, for example, a plunger tip that can slide in the sleeve 21 in the front-rear direction, and a plunger rod whose tip is fixed to the plunger tip, although not particularly designated.

  In the description of the present disclosure, when two members are fixed, the two members may be fixed by being integrally formed or joined to each other unless otherwise specified. Alternatively, they may be detachably connected by screws or the like.

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

  The injection drive unit 25 is fixed to the injection frame 15, for example. The configuration of the injection frame 15 may be similar to various known configurations, for example. For example, the injection frame 15 is a so-called C frame, and has a shape curved in a C shape as illustrated. Both ends of the C-shape are fixed to the fixed die plate 13 holding the fixed mold 103 of the mold clamping device 7. More specifically, for example, the injection frame 15 is viewed in the mold opening / closing direction of the fixed die plate 13 (as viewed in the left-right direction on the paper surface), and at the center side in the horizontal direction, the back surface (the mold 101). Both ends are fixed on the top and bottom of the opposite side. The injection frame 15 may be regarded as a part of the injection device 9.

(Driving drive unit drive system)
FIG. 2 is a schematic cross-sectional view showing the configuration of the injection driving unit 25. 2 is a view of the injection drive unit 25 viewed in the same direction as FIG. That is, the vertical direction of the paper surface is a vertical direction, and the horizontal direction of the paper surface and the through direction of the paper surface are horizontal directions.

  The injection drive unit 25 is an all-electric type, and includes a rotary motor 31 and a screw mechanism 33 for converting the rotation of the motor 31 into a translational motion. When the translational motion is transmitted from the screw mechanism 33 to the plunger 23, the plunger 23 moves forward and backward in the sleeve 21. Transmission of rotation from the electric motor 31 to the screw mechanism 33 is performed via, for example, a winding transmission mechanism 35. The screw mechanism 33 and the plunger 23 are connected via an injection rod 37, for example. These specific configurations are, for example, as follows.

(Electric motor)
Although not particularly shown, the electric motor 31 includes a stator that constitutes one of a field and an armature, and a rotor that constitutes the other of the field and the armature and rotates with respect to the stator. The electric motor 31 may be of an appropriate type. For example, the electric motor 31 may be a DC motor, an AC motor, a synchronous motor, or an induction motor. And a thing with a brake may be sufficient and a low inertia motor may be sufficient.

  The number of electric motors 31, the arrangement position, and the direction of arrangement may be set as appropriate. In the illustrated example, the electric motor 31 is arranged in parallel to the screw mechanism 33 with the output shaft 31a facing rearward. By the parallel arrangement, the injection driving unit 25 can be easily shortened. Further, for example, only one electric motor 31 is provided above (or below) the screw mechanism 33. More specifically, for example, the positions in the left-right direction of both axial centers coincide. Thereby, the injection | emission drive part 25 is easy to make width (paper surface penetration direction) small.

  The electric motor 31 is configured as a servo motor, for example. For example, the position and speed of the electric motor 31 are feedback-controlled by the control unit 5 based on a detection value of a position sensor (not shown) that detects the position of the plunger 23 (full closed loop control is performed). The electric motor 31 may be subjected to open control, or may be subjected to semi-closed loop control based on a detection value of a sensor that detects rotation of the electric motor 31 in addition to or instead of the full closed loop.

(Screw mechanism)
The screw mechanism 33 includes a screw shaft 39 and a nut 41 that is screwed onto the screw shaft 39. The screw shaft 39 is allowed to rotate around the axis and is restricted from moving in the axial direction. On the other hand, the nut 41 is restricted from rotating around the axis and is allowed to move in the axial direction. Therefore, when the rotation of the electric motor 31 is transmitted to the screw shaft 39, the nut 41 moves in the axial direction.

  The screw mechanism 33 may be a ball screw mechanism in which a ball is interposed between the screw shaft 39 and the nut 41, or may be a sliding screw mechanism in which no ball is interposed. As can be understood from the fact that the screw mechanism 33 may be a ball screw mechanism, when the screw shaft and the nut are screwed together, it is necessary that they are screwed (contacted) directly. No. The screw mechanism 33 may be of a single thread type with one thread groove, or may be of a multiple thread type with two or more thread grooves.

  The screw shaft 39 may be a solid shaft shape or a hollow shape (tubular shape). In the screw shaft 39 and the nut 41, the diameter, the length in the axial direction, the pitch of the thread groove, and the like may be set as appropriate. In the illustrated example, the nut 41 is formed relatively long in the axial direction. For example, the axial length of the nut 41 is at least three times the outer diameter of the screw shaft 39.

  The screw mechanism 33 is disposed coaxially with the plunger 23. That is, the shaft centers of the screw shaft 39 and the nut 41 are generally positioned on the extension of the shaft center of the plunger 23. Accordingly, the plunger 23 moves in the axial direction by the axial drive of the screw mechanism 33.

(Wound transmission mechanism)
The winding transmission mechanism 35 is, for example, a pulley / belt mechanism. The input pulley 43 is coaxially fixed to the output shaft 31a of the electric motor 31; And an output pulley 47 that is coaxially fixed to the screw shaft 39. The belt 45 may be, for example, a toothed belt or may have no teeth.

  The rotation of the electric motor 31 is sequentially transmitted to the input pulley 43, the belt 45, and the output pulley 47 and input to the screw mechanism 33 (screw shaft 39). The winding transmission mechanism 35 contributes to, for example, improving the degree of freedom of arrangement of the electric motor 31 with respect to the screw mechanism 33. Specifically, for example, the winding transmission mechanism 35 can be arranged in parallel with the screw mechanism 33 of the electric motor 31.

  The diameter of the input pulley 43 and the diameter of the output pulley 47 may be the same, or one may be larger than the other. That is, the winding transmission mechanism 35 may or may not contribute to deceleration or speed increase. In the illustrated example, the diameter of the output pulley 47 is larger than the diameter of the input pulley 43. Accordingly, the rotation of the electric motor 31 is increased and input to the screw mechanism 33.

  Detailed shapes of the input pulley 43 and the output pulley 47 may be set as appropriate. In the illustrated example, the output pulley 47 has a recess that accommodates a rear end of a support structure (described later) of the screw mechanism 33. Thus, the output pulley 47 can be positioned forward by the amount accommodated.

(Injection rod)

  The injection rod 37 is coaxially connected to the rear end of the plunger 23 (see FIG. 1) and is fixed coaxially to the front end of the nut 41. Therefore, when the nut 41 moves in the axial direction, the plunger 23 moves in the axial direction.

  The injection rod 37 is formed in a hollow shape through which the screw shaft 39 can be inserted, for example. In other words, the injection rod 37 has a cylindrical portion 37a. The cylindrical portion 37a has, for example, a cylindrical shape, and occupies most of the length of the injection rod 37. The inner diameter of the cylindrical portion 37 a is set slightly larger than the outer diameter of the screw shaft 39. Therefore, the cylindrical portion 37a (injection rod 37) and the screw shaft 39 are not in contact with each other. However, it is not impossible for the screw shaft 39 to slide on the cylindrical portion 37a.

  The injection rod 37 and the plunger 23 may be appropriately connected. For example, in the illustrated example, the injection rod 37 has a connecting portion 37b fixed to the front end of the cylindrical portion 37a. The connecting portion 37b is, for example, not provided with a reference numeral, and is located at the front end of the cylindrical portion 37a, a disc-like portion that closes the front end of the cylindrical portion 37a, a shaft-like portion that protrudes forward from the disc-like portion, And a flange. Although not particularly illustrated, the rear end portion of the plunger 23 is also shaped to have a flange. And the front-end part of the connection part 37b is mutually fixed by the rear-end part of the plunger 23 and a well-known coupling (refer FIG. 1 and code | symbol abbreviation).

  The injection rod 37 and the nut 41 may be fixed as appropriate. For example, in the illustrated example, the rear end portion 37c of the injection rod 37 has a shape having a flange. Moreover, the front end part of the nut 41 is also made into the shape which has a flange. And the rear-end part 37c and the front-end part of the nut 41 are being fixed with the volt | bolt and nut which are not shown in figure.

(Support structure for injection drive)
The drive system from the electric motor 31 to the injection rod 37 described above may be supported by a support structure having an appropriate configuration. For example, the injection drive unit 25 includes a hollow (tubular) support portion 49 that extends rearward from the injection frame 15 and supports the screw mechanism 33 and the injection rod 37 while being accommodated. More specifically, the support portion 49 supports the injection rod 37 via the bush 55 at the front end thereof. Moreover, the support part 49 is supporting the screw shaft 39 via the bearing 57 in the rear end, for example.

  Although not particularly illustrated, the support portion 49 may be provided with a portion that supports the electric motor 31. Although not particularly illustrated, the support portion 49 may be provided with a buffer member that abuts against the injection rod 37 and restricts the advance slightly before the nut 41 reaches the advance limit defined by the thread groove. Good. Similarly, although not particularly illustrated, the support portion 49 may be provided with a buffer member that abuts against the nut 41 and restricts the retreating slightly before the nut 41 reaches the retreat limit defined by the thread groove. Good.

  The structure of the support part 49, the bush 55, and the bearing 57 is as follows, for example.

(Support part)
For example, the support portion 49 supports the injection rod 37 so as to be movable back and forth at the front end thereof, and supports the screw shaft 39 so as to be rotatable and not movable in the axial direction at the rear end thereof. Accordingly, the drive mechanism including the injection rod 37 and the screw mechanism 33 is supported at the front and rear ends by the support portion 49, and is supported by the injection frame 15 through the support portion 49.

  Further, since the support portion 49 supports the screw shaft 39 so as not to move in the axial direction, the backward force applied to the screw shaft 39 when the nut 41 (plunger 23) is advanced is the support portion 49. To the injection frame 15. In other words, the support portion 49 contributes to receiving a radiant output.

  Although the screw mechanism 33 and the injection rod 37 are supported only at the front and rear ends as described above, the nut 41 or the injection rod 37 may be supported slidably forward and backward at other positions. . Further, the support portion 49 may be supported by a member (for example, a leg) other than the injection frame 15 in addition to (or instead of) the injection frame 15.

  The support portion 49 may be configured by appropriately combining a plurality of members. For example, the support 49 includes a hollow member 51 fixed to the injection frame 15 and a rear end member 52 fixed to the rear end of the hollow member 51.

(Hollow member)
The hollow member 51 is made of, for example, a casting (in other words, metal) integrally formed as a whole. The hollow member 51 is generally a cylindrical member concentric with the screw mechanism 33 and covers the outer periphery of the screw mechanism 33 (accommodates the screw mechanism 33). More specifically, the hollow member 51 has a front surface portion that covers not only the tubular portion but also the front portion of the tubular portion, and an injection rod 37 is provided on the front surface portion, although not particularly designated. A hole to be inserted is formed. The shape of the cross section (the shape of the inner peripheral surface and / or the shape of the outer peripheral surface) of the hollow member 51 (cylindrical portion) may be an appropriate configuration such as a circle or a rectangle, for example, a circle.

  Various dimensions of the hollow member 51 may be set as appropriate. In the illustrated example, the inner diameter of the hollow member 51 is slightly larger than the connecting portion (maximum diameter portion) of the injection rod 37 and the nut 41. That is, the injection rod 37 and the nut 41 do not slide on the inner surface of the hollow member 51 (its cylindrical portion) (in another aspect, it is not supported by the cylindrical portion of the hollow member 51). However, it is also possible to make it slide. In the illustrated example, the length of the hollow member 51 in the front-rear direction is, for example, a length that can accommodate the entire portion of the screw shaft 39 where the thread groove is cut.

  The hollow member 51 may be fixed to the injection frame 15 by an appropriate method. In the example shown in the figure, the front end of the hollow member 51 has a protrusion, and this protrusion is fitted into a hole formed in the injection frame 15, although no reference numeral is given. In addition, the male screw inserted through the injection frame 15 is screwed into a female screw portion formed in a peripheral portion of the protrusion in the front end portion of the hollow member 51. In this way, the hollow member 51 is fixed to the injection frame 15.

(Rear end member)
The rear end member 52 is, for example, a cylindrical member that is generally concentric with the screw mechanism 33, and covers (accommodates) the outer periphery of a portion of the screw shaft 39 where the rear screw groove is not formed. ing). More specifically, the rear end member 52 has a rear surface portion that closes not only the cylindrical portion but also the rear portion of the cylindrical portion. A hole through which is inserted is formed. The cross-sectional shape (the shape of the inner peripheral surface and / or the shape of the outer peripheral surface) of the rear end member 52 (cylindrical portion) may be an appropriate configuration such as a circle or a rectangle, for example, a circle.

  The rear end member 52 may be fixed to the hollow member 51 by an appropriate method. In the example shown in the figure, although not particularly designated, the rear end portion of the hollow member 51 and the front end portion of the rear end member 52 are each formed thick outward. Then, the rear end member 52 is fixed to the hollow member 51 by the male screw inserted through the thick portion of the rear end member 52 being screwed into the female screw portion formed in the thick portion of the hollow member 51. Yes.

(Bush)
The bush 55 is a substantially cylindrical metal member, and is fitted and attached to the hole on the front end surface of the hollow member 51 described above. An injection rod 37 is inserted into the bush 55 so as to be slidable in the front-rear direction. In the illustrated example, the bush 55 is provided with a flange and is inserted through the hollow member 51 from the front. However, the insertion direction may be reversed, and the bush 55 may have no flange. The method of fixing the bush 55 to the hollow member 51 may be a known appropriate method such as a method using a set screw or a retaining ring.

  For example, the bush 55 is not fixed directly to the injection frame 15, but is only fixed to the hollow member 51. The injection rod 37 is supported so as to be slidable only through the bush 55. Therefore, the support of the bush 55 and the injection rod 37 is completed within the support portion 49. That is, in the present embodiment, the support 49 may be fixed to the injection frame 15, and there is no need to attach a bush or the like to the injection frame 15. However, a bush may be provided on the injection frame 15.

(bearing)
The bearing 57 supports the screw shaft 39 so that the screw shaft 39 cannot move in the axial direction and can rotate around the shaft. The bearing 57 is housed and fixed in the rear end member 52. Thereby, the screw shaft 39 is supported by the support portion 49 so as not to move in the axial direction and to rotate around the shaft. The specific configuration of the bearing 57 may be the same as that of various known bearings.

(Rotation stopper for translational element of screw mechanism)
FIG. 2 is a bottom view showing a part of the injection driving unit 25.

  As described above, in the screw mechanism 33, the rotation of the nut 41 around the axis is restricted. Therefore, when the screw shaft 39 screwed to the nut 41 rotates around the axis, the nut 41 moves in the axial direction. Moving. Here, as shown in FIGS. 2 and 3, the restriction of the rotation of the nut 41 around the axis is realized by a guide groove 51a and a guided portion 53 guided by the guide groove 51a.

  Specifically, the guide groove 51 a is formed in the support portion 49. That is, the guide groove 51a is provided so as not to move with respect to the injection frame 15 (in other words, the fixed portion of the die casting machine 1). Further, the guide groove 51a extends, for example, in the axial direction of the screw mechanism 33 (has a length). On the other hand, the guided portion 53 is supported by the injection rod 37, and as a result, the nut 41 is restricted from moving in the axial direction of the screw mechanism 33 and around the axis of the screw mechanism 33. The guided portion 53 is inserted into the guide groove 51a. The diameter (width) of the portion inserted into the guide groove 51a of the guided portion 53 is slightly smaller than the width of the guide groove 51a.

  In such a configuration, when the screw shaft 39 is rotated in one direction, the nut 41 also tries to rotate in the one direction. At this time, the guided portion 53 comes into contact with one of the pair of inner wall surfaces (the pair of guide surfaces 51b) of the guide groove 51a. As a result, the rotation of the nut 41 in the one direction is restricted. Since the guided portion 53 is allowed to move in the axial direction within the range of the length of the guide groove 51a, the nut 41 moves to one side in the axial direction (for example, advances).

  Similarly, when the screw shaft 39 is rotated in the other direction, the nut 41 also tries to rotate in the other direction. At this time, the guided portion 53 comes into contact with the other of the pair of inner wall surfaces (the pair of guide surfaces 51b) of the guide groove 51a. As a result, the rotation of the nut 41 in the other direction is restricted. Since the guided portion 53 is allowed to move in the axial direction within the range of the length of the guide groove 51a, the nut 41 moves to the other side in the axial direction (for example, retreats).

  Specific configurations of the guide groove 51a (hollow member 51) and the guided portion 53 are, for example, as follows.

(Guide groove)
The guide groove 51a is constituted by, for example, a slit that penetrates the hollow member 51 (its cylindrical portion) inward and outward. From another viewpoint, the hollow member 51 has a pair of guide surfaces 51b with which the guided portion 53 abuts. The pair of guide surfaces 51 b face each other around the axis of the screw mechanism 33 and have a length (extend) in the axial direction of the screw mechanism 33.

  The guide grooves 51a (a pair of guide surfaces 51b) extend in parallel to the axial direction of the screw mechanism 33, for example. In this case, from another viewpoint, the pair of guide surfaces 51b extend parallel to each other. In still another aspect, the guide groove 51a (a pair of guide surfaces 51b) extends linearly.

  In the direction around the axis of the screw mechanism 33, the number and position of the guide grooves 51a may be set as appropriate. In the illustrated example, only one guide groove 51 a is provided and is positioned below the screw mechanism 33. More specifically, for example, the center line of the guide groove 51 a is located directly below the axis of the screw mechanism 33. For example, the guide groove 51 a is within the width of the screw mechanism 33 or the screw shaft 39 when viewed through the plane.

  The length of the guide groove 51 a is, for example, a length that does not restrict the drive range of the screw mechanism 33 by the guide groove 51 a and the guided portion 53. That is, the distance that the guided portion 53 can move in the guide groove 51 a is longer than the distance that the nut 41 can move relative to the screw shaft 39.

  The distance that the nut 41 can move with respect to the screw shaft 39 (the distance from the forward limit to the reverse limit) is a distance defined by the screw mechanism 33 itself (for example, the arrangement range of the screw groove). Alternatively, it may be a distance defined by a stopper provided in the support portion 49. Further, it is not impossible to define the drive range of the screw mechanism 33 by the guide groove 51a and the guided portion 53.

  The hollow member 51 has, for example, ribs 51c extending along the guide groove 51a on both sides of the guide groove 51a. Thereby, for example, a decrease in the strength of the hollow member 51 due to the formation of the guide groove 51a is compensated. In addition, the rib 51c is not provided except the position of the both sides of the guide groove 51a, for example. The distance between the guide groove 51a and the rib 51c is, for example, not more than the width of the guide groove 51a.

(Guide part)
The guided portion 53 includes, for example, a shaft body 59 and a rotating body 61 supported by the shaft body 59.

  The shaft body 59 is restricted from moving relative to the nut 41 (injection rod 37) in the axial direction of the screw mechanism 33 and the axis of the screw mechanism 33. The axial direction of the shaft body 59 is a direction intersecting the axial direction of the screw mechanism 33 (specifically, the radial direction of the screw mechanism 33). On the other hand, the rotating body 61 is supported by the shaft body 59 so as to be rotatable around the axis of the shaft body 59 with respect to the nut 41. The rotating body 61 has a radial position of the screw mechanism 33 equivalent to that of the guide groove 51a, and can contact the pair of guide surfaces 51b around the axis of the screw mechanism 33.

  Therefore, as described above, when the guided portion 53 is guided to the guide surface 51b, the rotating body 61 rolls on the guide surface 51b. Specifically, when the nut 41 moves forward, the guided portion 53 rolls on one of the pair of guide surfaces 51 b and rotates in one direction around the axis of the shaft body 59. Further, when the guided portion 53 moves backward, the guided portion 53 rolls on the other of the pair of guide surfaces 51 b and rotates in the one direction around the axis of the shaft body 59.

  Here, if the rotating body 61 is fitted in the guide groove 51a and is in contact with both of the pair of guide surfaces 51b, the operation of the rotating body 61 rolling on one guide surface 51b is the other guide surface. It is inhibited by the frictional resistance of 51b. However, since the diameter of the rotating body 61 is smaller than the width of the guide groove 51a, such inconvenience is eliminated. The difference between the diameter of the rotating body 61 and the width of the guide groove 51a may be small, for example, 0.1 mm or less.

  The configurations of the shaft body 59 and the rotating body 61 may be appropriate. For example, the rotating body 61 is configured by a roller follower (a bearing from another viewpoint). Although not particularly illustrated, the roller follower includes, for example, an inner ring, an outer ring, a plurality of needle rollers interposed therebetween, and a cage that holds the plurality of needle rollers. . The shaft body 59 is, for example, a nut 41 (directly the rear end portion 37c of the injection rod 37) and a roller shaft fixed to the inner ring.

  In the example using the roller follower described above, the rotating body 61 rotates around the axis of the shaft body 59 with respect to the nut 41 by rotating the rotating body 61 around the axis of the shaft body 59. In this example, strictly speaking, the outer ring of the roller follower is a rotating body that rolls on the guide surface 51b.

(Supplying lubricating oil to the screw mechanism)
As shown in FIG. 2, the injection drive unit 25 includes, for example, one or more (four in the illustrated example) hoses extending from the outside of the support unit 49 (hollow member 51) to the nut 41 via the guide groove 51a. 63. The hose 63 is used, for example, to supply lubricating oil between the nut 41 and the screw shaft 39.

  Specifically, the hose 63 is a flexible tubular member. One end of the hose 63 is connected to a hole (not shown) penetrating from the inner peripheral surface of the nut 41 to the outer peripheral surface. The other end of the hose 63 is connected to a lubricating oil supply unit (not shown). The lubricating oil supply unit supplies lubricating oil to the hose 63 using a pump or gravity.

  The position to which the hose 63 of the nut 41 is attached is, for example, located behind the guided portion 53 (in another aspect, one in the axial direction). The hose 63 is passed through the guide groove 51 a behind the guided portion 53. When the nut 41 moves back and forth, the part of the hose 63 connected to the nut 41 also moves forward and backward, and as a result, the hose 63 moves in the front and rear direction in the guide groove 51a.

  When the nut 41 is moved between the backward limit and the forward limit, a part of the moving range of the hose 63 (a front part in the illustrated example) is a part of the moving range of the guided portion 53 (the illustrated example). It overlaps with the rear part. From another viewpoint, even if the guided portion 53 is moved to the one side until the screw mechanism 33 reaches one (rear in the illustrated example) driving limit, the hose 63 is attached to the one side rather than the guided portion 53. The length that can be passed is secured in the guide groove 51a.

  The number of the hoses 63 and the mounting position of the hose 63 with respect to the nut 41 may be set as appropriate. In the illustrated example, the mounting positions of a plurality of (four) hoses 63 are evenly arranged along the guide groove 51 a on the guide groove 51 a side of the nut 41. Further, when the guided portion 53 is located at the drive limit on the hose 63 side (in the illustrated example, the backward limit; defined by the drive limit of the screw mechanism 33), for example, some of the plurality of attachment positions Is within the range of the length of the guide groove 51a, and the rest is located outside the range of the length of the guide groove 51a. In addition, all the attachment positions may be located within the range of the above length or outside the range.

  As described above, in the present embodiment, the injection device 9 for moving the plunger 23 slidable in the sleeve 21 communicating with the mold 101 back and forth includes the screw mechanism 33, the electric motor 31, and the pair of guide surfaces 51b. And a guided portion 53. The screw mechanism 33 has a screw shaft 39 and a nut 41 screwed into the screw shaft 39. The nut 41 can be coaxially connected to the plunger 23. The screw shaft 39 is restricted from moving in the axial direction. The electric motor 31 generates a driving force that rotates the screw shaft 39. The pair of guide surfaces 51 b face each other around the axis of the screw mechanism 33 and have a length in the axial direction of the screw mechanism 33. The guided portion 53 is restricted from moving in the axial direction of the screw mechanism 33 relative to the nut 41 and around the axis of the screw mechanism 33, and is inserted between the pair of guide surfaces 51b from the screw mechanism 33 side.

  Therefore, as described above, the guided portion 53 contacts the pair of guide surfaces 51b around the axis of the screw mechanism 33, so that the rotation of the nut 41 around the axis is restricted. On the screw mechanism 33 side, it is only necessary to project the guided portion 53, so that the configuration can be simplified and / or downsized.

  In the present embodiment, the guided portion 53 includes a shaft body 59 and a rotating body 61. The shaft body 59 is restricted from moving in the axial direction of the screw mechanism 33 relative to the nut 41 and around the axis of the screw mechanism 33, and the direction intersecting the axial direction of the screw mechanism 33 is defined as the axial direction. The rotating body 61 is supported by the shaft body 59 so as to be rotatable about the axis of the shaft body 59 with respect to the nut 41, and has a smaller diameter than the distance between the pair of guide surfaces 51b, and the pair of guide surfaces 51b. Located between.

  Therefore, as described above, in the guided portion 53, the rotating body 61 rolls when being guided by the respective guide surfaces 51b. Thereby, sliding resistance is reduced. By reducing the sliding resistance, for example, the accuracy of drive control of the plunger 23 by the electric motor 31 is improved. Or the lifetime of the guide surface 51b etc. becomes long.

  In the present embodiment, the injection device 9 further includes a support portion 49 (or a hollow member 51) extending in the axial direction of the screw mechanism 33. A guide groove 51a extending in the axial direction of the screw mechanism 33 is formed in the support portion 49, and a pair of guide surfaces 51b is constituted by a pair of inner wall surfaces of the guide groove 51a.

  Therefore, for example, compared with an aspect in which a pair of rails is provided to form a pair of guide surfaces 51b (this aspect is also included in the technology according to the present disclosure), one member in which the guide grooves 51a are formed. The guide groove 51a may be formed in a member that is necessarily arranged around the screw mechanism 33, and the configuration can be simplified and / or downsized easily.

  In the present embodiment, the support portion 49 (or the hollow member 51) is a hollow member that covers the outer periphery of the screw mechanism 33.

  Therefore, the support portion 49 serves as both a member that protects the screw mechanism 33 and a member that guides the guided portion 53. From another viewpoint, the guided portion 53 can be guided only by forming a groove in the member that protects the screw mechanism 33. As a result, for example, it is easy to simplify and / or reduce the size of the configuration.

  In this embodiment, the guide groove 51a penetrates the support portion 49 (or the hollow member 51) from the inside to the outside. The injection device 9 further includes a hose 63 extending from the outside of the support portion 49 to the nut 41 via the guide groove 51a. The movement range of the guided portion 53 and the movement range of the hose 63 corresponding to the movement range of the nut 41 from the backward limit to the forward limit partially overlap each other.

  Therefore, first, since the guide groove 51a is a through groove, the guide groove 51a is easy to form as compared with an aspect that is a concave groove (this aspect is also included in the technology according to the present disclosure). In addition, since the guided portion 53 may protrude outward from the support portion 49, the degree of freedom in designing the guided portion 53 is also improved. Further, the guide groove 51 a is used not only for guiding the guided portion 53 but also for extending the hose 63 from the inside of the support portion 49 to the outside. As a result, for example, the configuration can be simplified and / or downsized.

  In the present embodiment, the axial direction of the screw mechanism 33 is a horizontal direction, and a guide groove 51a penetrating the support portion 49 from the inside to the outside is provided only below the support portion 49 (hollow member 51). ing.

  In this case, for example, it is easy to reduce the width of the injection driving unit 25 as compared with an aspect in which the guide groove 51a is formed on the side (this aspect is also included in the technology according to the present disclosure). By reducing the width of the injection drive unit 25, for example, it is easy to secure a space for arranging a furnace and / or peripheral equipment. Further, for example, compared to an aspect in which the guide groove 51a is formed upward (this aspect is also included in the technology according to the present disclosure), there is a risk that dust or the like may enter the support portion 49 through the guide groove 51a. Reduced.

  In the present embodiment, the support portion 49 includes a hollow member 51 that is integrally formed in a hollow shape that covers the screw mechanism 33. The hollow member 51 has one end fixed to the injection frame 15 and the other end supporting the screw shaft 39 so as not to move in the axial direction (rear end member 52. In another aspect, the bearing 57 is fixed. Part.) Is fixed.

  Therefore, the support portion 49 is also used for receiving the radiation output in addition to the protection of the screw mechanism 33 and the guidance of the guided portion 53. As a result, for example, simplification and / or size reduction of the configuration is facilitated. Since the hollow member 51 only needs to form a guide groove 51a as a configuration for guiding the guided portion 53 (it is not necessary to provide a linear guide rail), the hollow member 51 guides the guided portion 53. It is easy to form a unitary structure including the above. And since it is integrally formed, it is easy for the hollow member 51 to ensure the intensity | strength which receives a radiant power.

  In the present embodiment, the injection device 9 further includes an injection rod 37 that is interposed between the plunger 23 and the nut 41 and connects them. The injection rod 37 has a cylindrical portion 37 a that covers a portion closer to the plunger 23 than the nut 41 of the screw shaft 39. The hollow member 51 supports the cylindrical portion 37a so as to be movable in the axial direction.

  Therefore, for example, the injection rod 37 does not need to be slidably supported by the injection frame 15. Therefore, when the injection driving unit 25 is attached to the injection frame 15, the hollow member 51 may be attached to the injection frame 15, and the workability is high. In addition, it is easy to attach the injection drive unit 25 to the injection frame 15 to which a hydraulic injection drive unit (injection cylinder) can be attached. From another viewpoint, compatibility between the electric injection drive unit 25 and the hydraulic injection drive unit is also improved.

  In the above embodiment, the die casting machine 1 is an example of a molding machine. The nut 41 is an example of a translation element. The screw shaft 39 is an example of a rotating element. The support part 49 or the hollow member 51 is an example of an extending member.

  The technology according to the present disclosure is not limited to the above-described embodiments, 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 that molds a resin, or a molding machine that molds a material in which a thermoplastic resin or the like is mixed with wood flour. There may be. Further, the molding machine is not limited to horizontal mold clamping horizontal injection, and may be vertical mold clamping vertical injection, horizontal mold clamping vertical injection, vertical mold clamping horizontal injection, for example.

  Which of the screw shaft and the nut is the translation element or the rotation element may be the reverse of the embodiment. That is, the nut may be a rotating element and the screw shaft may be a translation element. In this case, the nut is not movable in the axial direction and is rotatable about the axis. The screw shaft is movable in the axial direction. The nut is rotated by the electric motor. The guided portion is restricted from moving in the axial direction of the screw mechanism and the axis of the screw mechanism with respect to the screw shaft, and contributes to the rotation prevention of the screw shaft.

  The pair of guide surfaces are not limited to those constituted by the pair of inner wall surfaces of the guide grooves as mentioned in the description of the embodiment. For example, the pair of guide surfaces may be constituted by two members (typically, two rails) arranged apart from each other around the axis of the screw mechanism.

  Further, as mentioned in the description of the embodiment, when the pair of guide surfaces is constituted by the pair of inner wall surfaces of the guide grooves, the guide grooves are extended members (support portions 49) that cover the outer periphery of the screw mechanism. Or it is not limited to what is formed in the hollow member 51). In another aspect, the injection device does not need to have a hollow extending member that covers the screw mechanism.

  Further, as mentioned in the description of the embodiment, the pair of guide surfaces (guide grooves from another viewpoint) is not limited to the lower side, and may be provided at any position around the axis of the screw mechanism. Further, a combination of a pair of guide surfaces and guided portions may be provided at a plurality of positions around the axis of the screw mechanism.

  The pair of guide surfaces need only face each other in a direction facing each other around the axis of the screw mechanism. In other words, the pair of guide surfaces need not face each other in the tangential direction of the circumference around the screw mechanism. Therefore, for example, with respect to the angle around the axis of the screw mechanism, the angle between the pair of guide surfaces may be relatively large. For example, the angle may be 45 ° or more, 90 ° or more, 180 ° or more, or 270 ° or more.

  As described in the description of the embodiment, the guided portion is guided to one guide surface when moving forward, and is guided to the other guide surface when moving backward. Therefore, when the angle between the pair of guide surfaces is large with respect to the size of the guided portion, the position of the guided portion at the time of forward movement and the guided position at the time of backward movement with respect to the position around the axis of the screw mechanism. This is very different from the position of the part. As a result, the positions of the translation elements (nuts or screw shafts), injection rods, and plungers around the axes also differ between forward movement and backward movement. On the other hand, the sliding resistance of these members varies depending on the position around the axis due to the influence of gravity or the like. From the above, for example, if the angle between the pair of guide surfaces is appropriately set, the degree of wear can be made uniform around the axis.

  In an embodiment in which the angle between a pair of guide surfaces is small as in the embodiment (for example, the play of the guided portion between one guide surface is 1 cm or less, 1 mm or less, or 0.1 mm or less), for example, forward movement Since the translation element or the like hardly rotates at the start or at the start of reverse movement, the rotation of the electric motor 31 can be converted into translation without waste. In addition, unintended rotation caused by external force (rotation that causes the guided portion to move away from the guide surface to be contacted) is also small. As a result, it is easy to save energy and / or improve the accuracy of drive control. Further, when the guide groove is formed in the hollow member, it is easy to ensure the strength of the hollow member because the guide groove is thin.

  Further, the pair of guide surfaces need only have a length in the axial direction of the screw mechanism, and do not need to extend in parallel to the axial direction. For example, at least one of the pair of guide surfaces may be inclined or meandering with respect to the axial direction when the hollow member is cut along the axial direction and the hollow member is expanded in a planar shape. Good.

  In the above-described aspect, the guided portion changes the position around the axis of the screw mechanism while being guided by the guide surface. In turn, the translation elements (nuts or screw shafts), injection rods and plungers change their position about the axis as they advance and / or retract. As described above, the sliding resistance of these members varies depending on the position around the axis due to the influence of gravity or the like. Therefore, for example, it is possible to reduce the possibility that the wear proceeds at a specific position around the axis.

  In the embodiment in which the pair of guide surfaces extend parallel to the axis of the screw mechanism as in the embodiment, for example, the translational element or the like hardly rotates during forward movement and / or backward movement. Can be converted into translational motion without waste. As a result, it is easy to save energy and / or improve the accuracy of drive control. Further, when the guide groove is formed in the hollow member, the guide groove is located only at a part of the position around the axis (because the guide groove does not divide the hollow member forward and backward), It is easy to ensure the strength of the member in the axial direction.

  As described in the embodiments, the guided portion may be a member that slides on the guide surface. When the guided portion is a sliding member, the width of the guided portion need not be smaller than the distance between the pair of guide surfaces. In other words, the guided portion may be fitted between a pair of guide surfaces.

  In the case where the guided portion includes a shaft body and a rotating body, the guided portion is not limited to a configuration including a roller follower. For example, the shaft body and the rotating body are fixed to each other, and the shaft body is supported so as to be rotatable about the axis of the shaft body with respect to the translation element. You may be able to rotate around an axis.

  The axial direction of the shaft body (in another aspect, the protruding direction of the guided portion) only needs to intersect the axial direction of the screw mechanism. For example, when the shaft center of the shaft body is extended, it is not necessary to pass through the shaft center of the screw mechanism. Further, when viewed from the side of the screw mechanism, the axial direction of the shaft body does not need to be orthogonal to the axial direction of the screw shaft. However, the rotation of the rotating body is smoother when it is orthogonal.

  Two or more guided portions may be provided for a pair of guide surfaces (one guide groove). For example, two or more guided portions may be provided at different positions in the axial direction of the screw mechanism and at the same position around the axis of the screw mechanism. Further, for example, two or more guided portions may be arranged at the same or different positions in the axial direction of the screw mechanism and may be in contact with different guide surfaces. For example, two or more guided portions may be fitted between a pair of guide surfaces.

  The guided portion only needs to be restricted from moving in the axial direction of the screw mechanism and around the axis of the screw mechanism with respect to the translation element of the screw mechanism. Therefore, it may be supported by the injection rod fixed to the translation element (in the embodiment, the nut 41) as in the embodiment, or may be directly supported by the translation element, unlike the embodiment.

  A member (in the embodiment, an injection rod) that is interposed between the translation element and the plunger and connects them is not limited to a cylindrical one. For example, when the translational element is a screw shaft, the injection rod may be constituted by a solid shaft-shaped member, or a non-shaft-shaped member may be used instead of the injection rod.

  When the hose is passed through the guide groove, the hose may be located in front of the guided portion, not behind the guided portion. For example, in the embodiment, the guided portion may be provided at the rear end of the nut 41, and a guide groove or the like may be formed in accordance with this.

  A transmission mechanism for transmitting the rotation of the electric motor to the screw mechanism (in the embodiment, the winding transmission mechanism 35) may not be provided. That is, the output shaft of the electric motor and the rotating element of the screw mechanism may be directly connected. In the case where a transmission mechanism is provided, the transmission mechanism may include other types such as a gear mechanism instead of or in addition to the winding transmission mechanism. The winding transmission mechanism may be of a type other than the pulley / belt mechanism, such as a sprocket / chain mechanism.

DESCRIPTION OF SYMBOLS 1 ... Die casting machine, 9 ... Injection apparatus, 21 ... Sleeve, 23 ... Plunger, 31 ... Electric motor, 33 ... Screw mechanism, 39 ... Screw shaft (rotating element), 41 ... Nut (translation element), 51b ... Guide surface, 53 ... guided part, 101 ... mold.

Claims (9)

An injection device for moving a plunger slidable back and forth in a sleeve communicating with a mold,
A screw shaft and a nut threadably engaged with the screw shaft, and one of the translation elements can be coaxially connected to the plunger, and the other rotation element in the axial direction. A screw mechanism that is restricted in movement;
An electric motor generating a driving force for rotating the rotating element;
A pair of guide surfaces facing each other around the axis of the screw mechanism and having a length in the axial direction of the screw mechanism;
A guided portion that is restricted from moving in the axial direction of the screw mechanism relative to the translation element and about the axis of the screw mechanism, and is inserted between the pair of guide surfaces from the screw mechanism side;
Having an injection device. The guided portion is
A shaft body in which the axial direction of the screw mechanism and the movement of the screw mechanism around the axis with respect to the translation element are restricted, and a shaft body whose axial direction intersects the axial direction of the screw mechanism;
The shaft is supported by the shaft so as to be rotatable about the shaft of the shaft relative to the translation element, and has a diameter smaller than the distance between the pair of guide surfaces and is positioned between the pair of guide surfaces. The injection device according to claim 1. An extension member extending in the axial direction of the screw mechanism;
The injection device according to claim 1 or 2, wherein a guide groove extending in an axial direction of the screw mechanism is formed in the extending member, and the pair of guide surfaces are constituted by a pair of inner wall surfaces of the guide groove. . The injection device according to claim 3, wherein the extending member is a hollow member that covers an outer periphery of the screw mechanism. The guide groove penetrates the extending member from the inside to the outside,
A hose extending from the outside of the extending member to the translation element via the guide groove is provided,
The injection device according to claim 4, wherein a part of a movement range of the guided portion and a movement range of the hose corresponding to a movement range from a backward limit to a forward limit of the translation element partially overlap each other. The axial direction of the screw mechanism is a horizontal direction,
The injection device according to claim 4 or 5, wherein the guide groove that penetrates the extending member from the inside to the outside is provided only below the extending member. The extending member includes a hollow member integrally formed in a hollow shape covering the screw mechanism,
The hollow member has one end fixed to the injection frame and the other end fixed to a member that supports the rotating element so as not to move in the axial direction. The injection device according to. An injection rod that is interposed between the plunger and the translation element to connect them;
The translation element is a nut;
The rotating element is a screw shaft;
The injection rod has a cylindrical portion that covers a portion closer to the plunger than the nut of the screw shaft,
The injection device according to claim 7, wherein the hollow member supports the cylindrical portion so as to be movable in an axial direction thereof. The injection device according to any one of claims 1 to 8,
A mold clamping device for clamping the mold;
An extrusion device for extruding a molded product from the mold;
Having a molding machine.

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