Injection molding machine

An injection molding machine includes a sub injection device configured to inject molten resin into a mold of a clamping device along a direction perpendicular to an opening/closing direction of the mold, a sub machine base configured to support the sub injection device, and a coupling unit provided on a main machine base configured to support a main injection device and the clamping device and couple the main machine base and the sub machine base together. The coupling unit includes a base provided on the main machine base, two fixed blocks fixed to the base, a guide bar bridged in parallel to the opening/closing direction of the mold by the two fixed blocks, and a movable block slidably fitted onto the guide bar. The movable block is connected to the sub machine base.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2016-116801 filed on Jun. 13, 2016, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an injection molding machine that includes a clamping device including a mold and which moves the mold in an opening/closing direction, and an injection device for injecting molten resin in the mold along the opening/closing direction of the mold, and further includes a sub injection device for injecting the molten resin in the mold along a direction perpendicular to the opening/closing direction of the mold.

Description of the Related Art

Japanese Laid-Open Patent Publication No. 07-144356 discloses a multicolor molding machine that includes a first injection device for injecting molten resin in a mold along an opening/closing direction of the mold, and a second injection device for injecting the molten resin in the mold along a direction perpendicular to the opening/closing direction of the mold.

Japanese Laid-Open Patent Publication No. 2002-205315 discloses that an injection device and a mold attachment platen of a clamping device are coupled to each other by a coupling unit in order to reduce relative displacement between the injection device and the clamping device due to a pressing force of a nozzle touch and thereby stabilize a nozzle touch state and an injection molding operation.

SUMMARY OF THE INVENTION

Japanese Laid-Open Patent Publication No. 07-144356 does not take into account influences of a pressing force and a reaction force thereof produced when a nozzle of the second injection device touches a mold. Therefore, the nozzle and a sprue bush of the mold are likely to become misaligned, and it is difficult to perform stable injection molding. Further, misalignment of the nozzle of the second injection device and the sprue bush of the mold in a direction (the opening/closing direction of the mold) perpendicular to an injection direction of the second injection device is not taken into account. Therefore, it is not possible to perform position adjustment.

Japanese Laid-Open Patent Publication No. 2002-205315 does not take into account misalignment of a nozzle of the injection device and the sprue bush of the mold in the direction perpendicular to the injection direction of the injection device. Therefore, it is not possible to perform position adjustment.

It is therefore an object of the present invention to provide an injection molding machine that can adjust misalignment of a nozzle of a sub injection device and a sprue bush of a mold while performing stable injection molding in the sub injection device.

According to the present invention, there is provided an injection molding machine that includes: a clamping device including a mold and configured to produce a clamping force by opening and closing the mold; an injection device configured to inject molten resin into the mold along an opening/closing direction of the mold; and a machine base configured to support the clamping device and the injection device, wherein the injection molding machine further includes: a sub injection device configured to inject molten resin into the mold along a direction perpendicular to the opening/closing direction of the mold; a sub machine base configured to support the sub injection device; and a coupling unit provided on the machine base and configured to couple the machine base and the sub machine base together, the coupling unit includes: a base provided on the machine base; two fixed blocks fixed to the base; a guide bar supported by and bridged (extended, suspended) between the two fixed blocks in parallel to the opening/closing direction of the mold; and a movable block slidably fitted onto the guide bar, and the movable block is connected to the sub machine base.

According to this configuration, by the coupling unit that couples the machine base and the sub machine base together, it is possible to adjust a position of the sub injection device in the opening/closing direction of the mold. Further, by the coupling unit, it is possible to completely mechanically balance an action and a reaction accompanying a pressing force of a nozzle touch of the sub injection device between the machine base and the sub machine base. As a result, it is possible to suppress a moment action in a tilting direction of the sub injection device and the nozzle of the sub injection device due to the pressing force of a nozzle touch, and perform stable molding.

In the present invention, the injection molding machine further includes a nozzle touch mechanism configured to move the sub injection device having a nozzle configured to inject molten resin, with respect to the sub machine base in the direction perpendicular to the opening/closing direction of the mold, and thereby cause the nozzle to touch the mold. Consequently, it is possible to cause the nozzle of the sub injection device to touch the mold, and injection molding can be performed by the sub injection device.

In the injection molding machine according to the present invention, the nozzle touch mechanism includes: a ball screw configured to be rotated by driving of a motor and screw-engaged with a screw-engagement portion of the sub injection device; and a coupling support member configured to rotatably support the ball screw and provided on the sub machine base, and the coupling support member is connected to the movable block. With the above feature, the reaction force of the pressing force of the nozzle touch of the sub injection device is transmitted to the machine base via the coupling unit. Consequently, it is possible to completely mechanically balance the action and the reaction of the pressing force of the nozzle touch of the sub injection device between the machine base and the sub machine base.

In the injection molding machine according to the present invention, the sub injection device is supported on the sub machine base with a linear guide bearing portion interposed therebetween, and the linear guide bearing portion is configured to enable movement of the sub injection device with respect to the sub machine base in the direction perpendicular to the opening/closing direction of the mold. Consequently, the sub injection device can perform a nozzle touch operation.

In the injection molding machine according to the present invention, the sub machine base includes: a fixed base; a guide rail provided on the fixed base in parallel to the opening/closing direction of the mold; and a movable base supported on the fixed base with the guide rail interposed therebetween, the movable base being movable in the opening/closing direction of the mold; and the movable base is connected to the coupling unit. Consequently, it is possible to easily adjust the position of the sub injection device with respect to the clamping device in the opening/closing direction of the mold.

In the injection molding machine according to the present invention, the coupling unit further includes a coupling block configured to couple the two fixed blocks and a stationary platen configured to fix a fixed mold of the mold. With the above feature, a force applied to the coupling unit due to a pressing force of the nozzle touch of the sub injection device is dispersed to the machine base and the stationary platen. Consequently, it is possible to reduce the force applied to the machine base. As a result, it is possible to lower rigidity of the machine base.

In the present invention, the injection molding machine further includes a machine base coupling portion configured to couple the machine base and the sub machine base below the coupling unit to maintain a relative position between the machine base and the sub machine base. Consequently, even when rapid acceleration or rapid deceleration of the moving platen of the clamping device causes movement of the position of the machine base, it is possible to maintain the relative position (relative positional relationship) between the machine base and the sub machine base.

According to the present invention, the coupling unit that couples the machine base and the sub machine base makes it possible to adjust the position of the sub injection device in the opening/closing direction of the mold. Further, the coupling unit makes it possible to completely mechanically balance the action and the reaction accompanying the pressing force of the nozzle touch of the sub injection device between the machine base and the sub machine base. As a result, it is possible to suppress the moment action in the tilting direction of the sub injection device and the nozzle of the sub injection device due to the pressing force of the nozzle touch, and perform stable molding.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of an injection molding machine according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1is an overall plan view showing an injection molding machine10, as viewed from above.FIG. 2is an overall side view showing the injection molding machine10, as viewed from a side. The injection molding machine10includes an injection device (hereinafter referred to as a main injection device)12, a clamping device14, a machine base (hereinafter referred to as a main machine base)16that supports the main injection device12and the clamping device14, a sub injection device18, a sub machine base20that supports the sub injection device18, and a coupling unit22that is arranged on the main machine base16and couples the main machine base16and the sub machine base20together.

The main injection device (first injection device)12includes an injection cylinder24, and injects molten resin in the injection cylinder24from a nozzle24aof the injection cylinder24into a mold26(more specifically, a cavity) of the clamping device14. The main injection device12and the clamping device14are disposed on the main machine base (first machine base)16so as to face each other along an opening/closing direction (which is referred to as “Direction A” below for ease of description) of the mold26. An axial direction of the injection cylinder24is parallel to Direction A. Hence, the main injection device12injects the molten resin in the mold26along Direction A (the opening/closing direction of the mold26).

An injection screw (not shown) is arranged in the injection cylinder24. When this injection screw moves while rotating toward the mold26, the molten resin in the injection cylinder24is injected from the nozzle24ainto the mold26. This injection cylinder24is heated by a heater or the like, and melts pelleted resin supplied from a hopper (not shown). In this regard, the injection screw is rotated and moved in Direction A by a driving source such as a servo motor (not shown) or the like.

The sub injection device (second injection device)18also has the same configuration as that of the main injection device12. To explain it briefly, the sub injection device18also includes an injection cylinder28, and injects molten resin in the injection cylinder28from a nozzle28aof the injection cylinder28into the mold26(more specifically a cavity). The sub injection device18is disposed on the sub machine base (second machine base)20so as to face the clamping device14along a direction (referred to as “Direction B” below for ease of description) perpendicular to the opening/closing direction of the mold26. An axial direction of the injection cylinder28is parallel to Direction B. Hence, the sub injection device18injects the molten resin in the mold26along Direction B (the direction perpendicular to the opening/closing direction of the mold26).

The clamping device14includes the mold26, and produces a clamping force by opening and closing the mold26. That is, the clamping device14performs operations of opening/closing and clamping the mold26. More specifically, the mold26includes a fixed mold26aand a movable mold26b. During molding, the clamping device14moves the movable mold26bin a closing direction (a direction to approach the fixed mold26a), causes the movable mold26bto contact the fixed mold26a, and then further moves the movable mold26bin the closing direction to thereby perform clamping operation. Further, after molding, the clamping device14moves the movable mold26bin the opening direction and causes the movable mold26band the fixed mold26ato move away from each other. The operation of opening and closing the mold26is performed by a driving source such as a servo motor (not shown).

The clamping device14includes a fixed platen (stationary platen)30, a rear platen32, and a plurality of tie bars34that couple the fixed platen30and the rear platen32together. A movable platen (moving platen)36is arranged between the fixed platen30and the rear platen32, and is movable in an axial direction of the tie bars34along the plurality of tie bars34. The fixed mold26ais attached to a surface of the fixed platen30on the movable platen36side. The movable mold26bis attached to a surface of the movable platen36on the fixed platen30side. Hence, the movable platen36moves in the axial direction (Direction A) of the tie bars34to open and close the mold26. This movable platen36is moved in the axial direction of the tie bars34by a driving mechanism that includes a toggle mechanism and a servo motor, which are not shown.

Next, the coupling unit22will be described in more detail.FIG. 3is a perspective view showing a configuration of the coupling unit22.FIG. 4is a perspective view showing a state where the coupling unit22is placed on the main machine base16. The coupling unit22is arranged at such a position that, when the main machine base16and the sub machine base20are coupled, a nozzle28aof the sub injection device18arranged on the sub machine base20can touch a sprue bush27(seeFIG. 4) of the mold26. More specifically, an installation position of the coupling unit22is near a position of the mold26of the clamping device14in Direction A, and is at one end portion side of the main machine base16in Direction B. The sprue bush27is arranged on a surface of the mold26at the sub injection device18side. Although not shown, a sprue bush corresponding to the nozzle24aof the main injection device12is arranged on a surface of the mold26at the main injection device12side.

The coupling unit22includes a base40, two fixed blocks42,42, a guide bar44, and two movable blocks46,46. The base40is detachably mounted on the main machine base16by a bolt (not shown) or the like. Since the base40is attachable and detachable, the coupling unit22is attachable and detachable with respect to the main machine base16. The base40supports (fixes) the two fixed blocks42,42. The base40is a flat plate of a substantially rectangular shape, and is installed on the main machine base16such that a longitudinal direction of the base40is parallel to Direction A.

The guide bar44is supported by the two fixed blocks42,42and is bridged (extended, suspended) in parallel to Direction A (the axial direction of the tie bars34). That is, one end of the guide bar44is fixed to one fixed block (first fixed block)42fixed to one end side of the base40in the longitudinal direction, and the other end of the guide bar44is fixed to the other fixed block (second fixed block)42fixed to the other end side of the base40in the longitudinal direction.

The two movable blocks46,46are slidably fitted on the guide bar44. That is, each of the two movable blocks46,46includes an insertion hole46aformed along Direction A. When the guide bar44is inserted in the insertion hole46a, each of the movable blocks46,46is slidably fitted on the guide bar44. Further, in each of the two movable blocks46,46, a fitting hole46binto which a coupling pin68(seeFIG. 6) to be described later is fitted is formed along Direction A. The two movable blocks46,46are disposed at a fixed interval so as to be fitted with respect to both end portion sides of the coupling pin68. The two movable blocks46,46are connected with the sub machine base20by the coupling pin68.

Thus, the two movable blocks46,46of the coupling unit22provided on the main machine base16are movable in Direction A with respect to the main machine base16(base40). The movable blocks46are connected with the sub machine base20. Consequently, it is possible to adjust the position of the sub injection device18in the direction A with respect to the main machine base16(clamping device14, mold26). Consequently, it is possible to adjust a touch position (nozzle touch position) of the nozzle28ain the direction A so as to coincide with the position of the sprue bush27of the mold26, and align the nozzle28awith the sprue bush27.

Another fixed block (third fixed block)42for fixing and supporting a center portion of the guide bar44may be further provided. The number of the movable blocks46may be one or may be three or more.FIG. 4shows an example where the sprue bush27is formed in the fixed mold26a. However, the sprue bush27may be formed in the movable mold26b, or the sprue bush27may be formed at a boundary between the fixed mold26aand the movable mold26b.

Next, a structure of the sub machine base20will be described in more detail.FIG. 5is a perspective view of the sub injection device18and the sub machine base20.FIG. 6is a plan view showing the sub injection device18and the sub machine base20, as viewed from above. The sub machine base20supports the sub injection device18so as to enable movement of the sub injection device18in Direction A and Direction B.

The sub machine base20includes a fixed base50, two guide rails52,52, a movable base54, and two linear guide bearing portions56,56. The two guide rails52,52are arranged on the fixed base50in parallel with Direction A. One guide rail52is arranged at one end side of the fixed base50in Direction B, and the other guide rail52is arranged at the other end side of the fixed base50in Direction B. The movable base54is supported on the fixed base50with the two guide rails52,52interposed therebetween. The two guide rails52,52support the movable base54on the fixed base50movably in Direction A with respect to the fixed base50. The number of the guide rails52may be one, or three or more.

The two linear guide bearing portions56,56are arranged on the movable base54in parallel with Direction B. One linear guide bearing portion56is arranged at one end side of the movable base54in Direction A, and the other linear guide bearing portion56is arranged at the other end side of the movable base54in Direction A. The sub injection device18is supported on the movable base54with the two linear guide bearing portions56,56interposed therebetween. The two linear guide bearing portions56,56support the sub injection device18on the movable base54movably in Direction B with respect to the movable base54. The sub injection device18is supported on the movable base54such that the nozzle28aof the injection cylinder28is directed to the mold26of the clamping device14.

In the present embodiment, a motor62to be described later is disposed between the linear guide bearing portions56,56. Therefore, the movable base54is made up of two support members54a,54aon which the two linear guide bearing portions56,56are arranged and which are disposed in parallel to Direction B, and two connection members54b,54bthat connect lower portions of the two support members54a,54a. The two connection members54b,54bare connected to the two guide rails52,52movably in Direction A. The number of linear guide bearing portions56may be one, or three or more. The motor62is arranged between the two support members54a,54a, and above the connection member54b.

A feed screw unit58is attached to the fixed base50and the movable base54. The feed screw unit58moves the movable base54in Direction A with respect to the fixed base50. The feed screw unit58includes a feed screw58a, an axial support member58bthat axially supports (supports) the feed screw58arotatably yet unmovably in the axial direction, an axial support member58cthat axially supports (supports) the feed screw58arotatably, and a nut portion58dthat is screw-engaged with the feed screw58a. The two axial support members58b,58care attached to the fixed base50, and the nut portion58dis attached to the movable base54. Hence, when the feed screw58arotates, the movable base54moves in Direction A with respect to the fixed base50. The feed screw58ais rotated by driving of a servo motor (not shown) or is manually rotated (by operating a handle attached to an end portion thereof).

The main injection device12is also supported on the main machine base16with the two linear guide bearing portions59interposed therebetween (seeFIG. 1and the like). The linear guide bearing portions59enable movement of the main injection device12in Direction A.

The sub machine base20is provided with a nozzle touch mechanism60. The nozzle touch mechanism60is a mechanism that moves the sub injection device18in Direction B with respect to the movable base54, and thereby causes the nozzle28aof the sub injection device18to touch the sprue bush27(seeFIG. 4) of the mold26. The nozzle touch mechanism60will be described also with reference toFIG. 7. In this regard, movement of the nozzle28ain a direction to approach the mold26will be referred to as forward movement, and movement of the nozzle28ain a direction to move away from the mold26will be referred to as backward movement.

The nozzle touch mechanism60includes the motor62such as a servo motor, a ball screw64, and a coupling support member66. The motor62is fixed to the movable base54, and is installed at an end portion of the movable base54on an opposite side (an opposite side of the nozzle28aof the sub injection device18) of the clamping device14in Direction B. The motor62is arranged above the connection member54bof the movable base54, and is fixed on a motor support member55that connects the two support members54a,54a. A rotary axis of the motor62and the ball screw64are connected to each other through a coupling portion63. The ball screw64is screw-engaged with a screw-engagement portion18a(seeFIG. 7) of the sub injection device18.

The coupling support member66axially supports (supports) a distal end of the ball screw64rotatably yet unmovably in the axial direction. Hence, when the ball screw64is rotated by driving of the motor62, the sub injection device18moves in Direction B. That is, when the motor62rotates forward, the sub injection device18moves forward (moves in the direction to approach the clamping device14), and when the motor62rotates reversely, the sub injection device18moves backward (moves in the direction to move away from the clamping device14).

The coupling support member66is connected to the two movable blocks46,46of the coupling unit22by the coupling pin68. The coupling support member66is formed along Direction A so as to straddle the two linear guide bearing portions56,56(support members54a,54a), and is supported on the movable base54(support members54a,54a) with the two linear guide bearing portions56,56interposed therebetween. Consequently, the coupling support member66is movable in Direction B with respect to the movable base54.

The coupling support member66can be fitted on the coupling pin68, which is fitted with the two movable blocks46,46. Consequently, the coupling pin68can connect the coupling unit22and the coupling support member66. Consequently, it is possible to couple the main machine base16and the sub machine base20together.

More specifically, the coupling support member66includes a Π-shaped base member66athat is formed along Direction A so as to straddle the two linear guide bearing portions56,56(support members54a,54a) and is supported on the movable base54, and a protrusion portion66bthat protrudes from the base member66atoward the clamping device14(mold26). The ball screw64is axially supported rotatably by the protrusion portion66b. The length of the protrusion portion66bin a width direction (Direction A) is shorter than the length of the base member66ain the width direction (Direction A).

A through hole (not shown) is formed in the protrusion portion66balong Direction A. By inserting the coupling pin68in the through hole, the coupling pin68is fitted with the protrusion portion66b. The coupling pin68is fitted with the protrusion portion66bsuch that a central axis of the coupling pin68and a central axis of the ball screw64lie in the same horizontal plane. By fitting the coupling pin68into the protrusion portion66band the two movable blocks46,46in a state where the two movable blocks46,46are disposed at a fixed interval sandwiching the protrusion portion66bfrom both end sides in Direction A, the coupling unit22and the coupling support member66are connected (seeFIG. 1). By providing a height-adjustable mount80(seeFIGS. 2 and 7) on a bottom portion of the fixed base50of the sub machine base20, it is possible to position central axes of the coupling pin68, the ball screw64, and the guide bar44on the same horizontal plane.

Thus, the coupling support member66is supported on the movable base54that is movable in Direction A with respect to the fixed base50, and is connected to the two movable blocks46,46of the coupling unit22that can move in Direction A. Consequently, it is possible to easily adjust the position of the sub injection device18in Direction A with respect to the clamping device14(mold26). Consequently, it is possible to easily adjust the touch position of the nozzle28awith respect to the mold26in Direction A, and facilitate positioning between the nozzle28aand the sprue bush27in Direction A.

FIG. 8is a perspective view showing a state where the coupling unit22and the coupling support member66are connected, whereby the main machine base16and the sub machine base20are coupled. In order to perform injection molding in the state shown inFIG. 8, when the movable mold26bis moved in a closing direction to close the mold26, and then the motor62is driven to rotate (rotate forward) the ball screw64, the sub injection device18moves forward along Direction B. After the nozzle28ahas been placed into contact with the sprue bush27of the mold26, the sub injection device18is further moved forward, whereby a pressing force of the nozzle28aagainst the mold26is produced. The pressing force is produced when the ball screw64pulls the coupling unit22in a direction to move away from the mold26. The central axes of the coupling pin68, the ball screw64, and the guide bar44lie in the same plane by adjusting the mount80, and the coupling support member66is supported by the two linear guide bearing portions56,56. Consequently, the guide bar44is pulled in the direction to move away from the mold26horizontally in Direction B.

The coupling unit22is fixed to the main machine base16. Therefore, a moment to pull the main machine base16in a direction toward the sub injection device18by a force (reaction force) due to the pressing force acts on the main machine base16. However, the main machine base16has such rigidity that the main machine base16is not deformed by the moment. Hence, an action and a reaction accompanying a pressing force are completely mechanically balanced between the main machine base16and the sub machine base20. Hence, a moment action in a tilting direction of the sub injection device18and the nozzle28adue to the pressing force of the nozzle touch is suppressed. Consequently, it is possible to suppress misalignment of the nozzle28aand the mold26and perform stable molding.

In the case where the sprue bush27of the mold26is not positioned within an adjustment range of the nozzle28aof the sub injection device18in Direction A, i.e., when positioning between the nozzle28aand the sprue bush27in Direction A cannot be achieved even by moving the movable blocks46in Direction A, the installation position of the coupling unit22may be changed. When, as shown in, for example,FIGS. 9A and 9B, the thicknesses (the lengths in Direction A) of the fixed molds26aprovided with the sprue bushes27significantly differ from each other, so that the positions of the sprue bushes27in Direction A significantly change, the installation position of the coupling unit22may be shifted in Direction A.

The embodiment can be modified as follows.

FIG. 10is a perspective view showing a configuration of a coupling unit22aaccording to the first modification. The same or similar components as or to those of the embodiment will be assigned the same reference numerals, and description thereof will be omitted.

The coupling unit22aincludes the base40, the two fixed blocks42,42, the guide bar44, and the two movable blocks46,46, and further includes a coupling block82. The coupling block82couples (connects) the two fixed blocks42,42and the fixed platen30together. The coupling block82is connected to surfaces of the two fixed blocks42,42on the mold26side by a fixing member such as a bolt. The coupling block82is connected to the two fixed blocks42,42above the two movable blocks46,46. The coupling block82is connected to a surface of the fixed platen30on the mold26(more specifically, the fixed mold26a) side by a fixing member such as a bolt. Consequently, it is possible to reduce a force applied to the main machine base16due to the pressing force produced when the nozzle28aof the sub injection device18touches the mold26. That is, the force applied to the coupling unit22adue to the pressing force is dispersed to the main machine base16and the fixed platen30. Consequently, it is possible to reduce the force applied to the main machine base16. As a result, it is possible to lower rigidity of the main machine base16.

FIG. 11is a perspective view showing a configuration of a coupling unit22baccording to the second modification. The same or similar components as or to those of the embodiment will be assigned the same reference numerals, and description thereof will be omitted.

The coupling unit22bincludes the base40, the two fixed blocks42,42, the guide bar44and the two movable blocks46,46and further includes a coupling block84. The coupling block84couples (connects) the two fixed blocks42,42and the fixed platen30together, as with the coupling block82according to the first modification. The coupling block84is connected to surfaces of the two fixed blocks42,42on the mold26side by a fixing member such as a bolt. The coupling block84is connected to the two fixed blocks42,42above the two movable blocks46,46. The coupling block84is connected to a surface of the fixed platen30on the sub injection device18(more specifically, the sub machine base20) side by a fixing member such as a bolt. Thus, it is possible to reduce a force applied to the main machine base16due to the pressing force produced when the nozzle28aof the sub injection device18touches the mold26. That is, the force applied to the coupling unit22bdue to the pressing force is dispersed to the main machine base16and the fixed platen30. Consequently, it is possible to reduce the force applied to the main machine base16. As a result, it is possible to lower the rigidity of the main machine base16.

In the embodiment, one sub injection device18and one sub machine base20are added (additionally installed) to the injection molding machine10. However, a plurality of sub injection devices18and a plurality of sub machine bases20may be added (additionally installed). In this case, a plurality of coupling units22are provided on the main machine base16.

FIG. 12is a plan view showing, as viewed from above, a state where the two coupling units22are disposed on the main machine base16.FIG. 13is a plan view showing, as viewed from above, a state where the main machine base16and the two sub machine bases20provided with the sub injection devices18are coupled through the two coupling units22. The same or similar components as or to those of the embodiment will be assigned the same reference numerals.

The installation positions of the two coupling units22in Direction A are near the mold26of the clamping device14, and, in Direction B, are on both end sides of the main machine base16. Hence, the two sub injection devices18and the two sub machine bases20are connected to the main machine base16such that the nozzles28aof the two sub injection devices18face each other. In the third modification, the sprue bushes27are formed respectively on both side surfaces of the mold26of the clamping device14in Direction B. The two sub machine bases20are coupled to the main machine base16through the coupling units22such that the nozzles28aof the two sub injection devices18can touch the two sprue bushes27.

Thus, the coupling unit22is attachable and detachable to and from the main machine base16. Consequently, it is possible to additionally install the two or more sub injection devices18to the injection molding machine10. The installation position of the coupling unit22installed on the main machine base16is not limited to that inFIG. 12, and the number of coupling units22on the main machine base16is arbitrary. For example, the two coupling units22may be disposed along Direction A at one end portion side of the main machine base16in Direction B, and one coupling unit22may be disposed at the other end portion side of the main machine base16in Direction B. In this case, the three sub injection devices18are additionally installed in the injection molding machine10.

FIG. 14is a sectional view of the injection molding machine10according to the fourth modification, taken along Direction B. The same or similar components as or to those of the embodiment will be assigned the same reference numerals, and description thereof will be omitted.

During high cycle molding, there is a case where the movable platen36(movable mold26b) of the clamping device14rapidly accelerates or rapidly decelerates, and this rapid acceleration or rapid deceleration may cause movement of the position of the main machine base16. There is a case where such movement of the position of the main machine base16may cause an excessive load to be applied to the coupling unit22, resulting in change of the relative position between the main machine base16and the sub machine base20. Hence, a machine base coupling portion86that couples the main machine base16and the sub machine base20together is provided in order to maintain the relative position (relative positional relationship) between the main machine base16and the sub machine base20. The machine base coupling portion86has strength to maintain the relative position with respect to the sub machine base20without deformation when the main machine base16moves.

The machine base coupling portion86is bridged between the main machine base16and the sub machine base20with one end screw-engaged into the main machine base16and the other end screw-engaged into the sub machine base20. The machine base coupling portion86couples the main machine base16and the sub machine base20at lower portions thereof. Hence, the machine base coupling portion86couples the main machine base16and the sub machine base20below the coupling unit22.

In the embodiment, the coupling support member66is supported on the movable base54with the two linear guide bearing portions56,56interposed therebetween. However, the coupling support member66may be supported directly on the movable base54(support members54a,54a). In this case, the guide rails52,52need to be rigid enough not to be deformed by a force due to the pressing force applied by the nozzle28aagainst the mold26, and enough to bear the pressing force.

Some of the first to fifth modifications may be arbitrarily combined in a way that does not cause inconsistency. For example, the first modification and the third modification may be combined according to one aspect, and the second, third and fourth modifications may be combined according to another aspect.

As described above, the injection molding machine10described in the embodiment or the first to fifth modifications includes the clamping device14that includes the mold26and produces a clamping force by opening and closing the mold26, the main injection device12that injects molten resin in the mold26along the opening/closing direction of the mold26, and the main machine base16that supports the clamping device14and the main injection device12. Further, the injection molding machine10includes the sub injection device18that injects molten resin in the mold26along the direction perpendicular to the opening/closing direction of the mold26, the sub machine base20that supports the sub injection device18, and the coupling unit22(22a,22b) that is arranged on the main machine base16and couples the main machine base16and the sub machine base20together. The coupling unit22(22a,22b) includes the base40that is arranged on the main machine base16, the two fixed blocks42,42that are fixed to the base40, the guide bar44that is bridged (extended, suspended) in parallel to the opening/closing direction of the mold26with one end supported by one fixed block42and with the other end supported by the other fixed block42, and the movable block46that is slidably fitted onto the guide bar44, and the movable block46is connected to the sub machine base20.

Thus, by using the coupling unit22(22a,22b) that couples the main machine base16and the sub machine base20together, it is possible to adjust the position of the sub injection device18in Direction A. Further, by using the coupling unit22(22a,22b), it is possible to completely mechanically balance an action and a reaction accompanying a pressing force of the nozzle touch of the sub injection device18between the main machine base16and the sub machine base20. As a result, it is possible to suppress the moment action in the tilting direction of the sub injection device18and the nozzle28adue to the pressing force of the nozzle touch, and perform stable molding.

The injection molding machine10further includes the nozzle touch mechanism60that moves the sub injection device18including the nozzle28afor injecting molten resin, in the direction perpendicular to the opening/closing direction of the mold26with respect to the sub machine base20, and causes the nozzle28ato touch the mold26. Consequently, the nozzle28aof the sub injection device18can touch the mold26, and injection molding can be performed by the sub injection device18.

The nozzle touch mechanism60includes the ball screw64that is rotated by driving of the motor62, and is screw-engaged with the screw-engagement portion18aof the sub injection device18, and the coupling support member66that rotatably supports the ball screw64and is arranged on the sub machine base20, and the coupling support member66is connected to the movable block46. Owing thereto, the reaction force of the pressing force of the nozzle touch of the sub injection device18is transmitted to the main machine base16via the coupling unit22(22a,22b). Consequently, it is possible to completely mechanically balance the action and the reaction accompanying the pressing force of the nozzle touch of the sub injection device18between the main machine base16and the sub machine base20.

The sub injection device18is supported on the sub machine base20with the linear guide bearing portions56being interposed therebetween, and the linear guide bearing portions56enable movement of the sub injection device18in the direction perpendicular to the opening/closing direction of the mold26with respect to the sub machine base20. Consequently, the sub injection device18can perform a nozzle touch operation.

The sub machine base20includes the fixed base50, the guide rails52that are arranged on the fixed base50in parallel to the opening/closing direction of the mold26, and the movable base54that is supported on the fixed base50with the guide rails52interposed therebetween, and can move in the opening/closing direction of the mold26, and the movable base54is connected to the coupling unit22(22a,22b). Consequently, it is possible to easily adjust the position of the sub injection device18in Direction A with respect to the clamping device14(mold26).

The coupling unit22a(22b) includes the coupling block82(84) that couples the two fixed blocks42and the fixed platen30that fixes the fixed mold26aof the mold26. With the above feature, the force applied to the coupling unit22a(22b) due to the pressing force of the nozzle touch of the sub injection device18is dispersed to the main machine base16and the fixed platen30. Consequently, it is possible to reduce the force applied to the main machine base16. As a result, it is possible to lower the rigidity of the main machine base16.

The machine base coupling portion86that couples the main machine base16and the sub machine base20below the coupling unit22(22a,22b) is further provided in order to maintain the relative position between the main machine base16and the sub machine base20. Consequently, even when rapid acceleration or rapid deceleration of the movable platen36of the clamping device14causes movement of the position of the main machine base16, it is possible to maintain the relative position (relative positional relationship) between the main machine base16and the sub machine base20.

In this regard, Japanese Laid-Open Patent Publication No. 2016-078384 discloses an injection molding device including a first injection machine that injects a resin material in a mold along an opening/closing direction of the mold, and a second injection machine that injects a resin material in the mold in a direction perpendicular to the opening/closing direction of the mold. Further, it discloses that the injection molding device further includes a moving mechanism that moves the second injection machine on a base so as to cause a nozzle of the second injection machine to touch the mold, and the moving mechanism is bridged between the second injection machine and the tie bars.

However, with a technique disclosed in Japanese Laid-Open Patent Publication No. 2016-078384, deflection of the tie bars cannot be completely suppressed even though the deflection is suppressed to an allowance value. Therefore, the technique has drawbacks of loss of a balance between the tie bars and a decrease in clamping accuracy. Therefore, there is a problem that stable molding cannot be performed or articles to be molded are limited. Coupling members of the moving mechanism are installed on the tie bars at positions on both sides of the nozzle of the second injection machine. Therefore, a movable range of a movable platen is narrow, and a mold size that can be used is also limited. Further, concerning coupling of the second injection machine and the tie bars by the moving mechanism, only a case where a force required for moving the second injection machine and a touch force are both small is taken into account. Therefore, the second injection machine is also limited to a small size. By contrast with this, the injection molding machine10according to the present embodiment and the modifications does not cause such a problem, and is useful.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood that variations and modifications can be effected thereto by those skilled in the art without departing from the scope of the invention as defined by the appended claims.