Injection molding machine

Abstract

To provide an injection molding machine capable of rotating an injection device without requiring labor for attachment and detachment of a nozzle touch rod.SOLUTION: An injection molding machine includes: an injection device 10 that injects a resin material melted in an injection cylinder 30 from a nozzle 31; a swivel pin 25 that rotatably connects the injection device 10 to a base 15 on which the injection device 10 is arranged; a fixed die 61 to which a mold 63 for molding the resin material injected from the nozzle 31 is attached; a plurality of nozzle touch rods 80 that are arranged parallel to an extension direction of the injection cylinder 30 in a state of injecting the resin material from the nozzle 31 to the mold 63 and have one end connected to a surface of the fixed die 61 on the injection device 10 side; and a housing 70 to which the plurality of nozzle touch rods 80 are arranged apart from the fixed die 61 and connected at a distance from the fixed die 61 and to which the injection device 10 is rotatably connected by a connecting pin 74 arranged on an axis of the swivel pin 25.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an injection molding machine.

Background Art

[0002] Among injection molding machines that perform molding by injecting resin melted in an injection cylinder into a mold, some are equipped with a nozzle touch mechanism that appropriately contacts a nozzle, which is a part for injecting the melted resin into the mold, with the mold. For example, in the injection molding machine described in Patent Document 1, a plurality of guide rods for nozzle touch that support an injection unit mechanism on a rear platen are erected via an air cylinder, and the nozzle touch and sprue break operations are performed by the air cylinder.

[0003] In addition, among injection molding machines, there are those in which the injection cylinder extends in the horizontal direction. Some injection molding machines with a horizontally extending injection cylinder are configured in consideration of high maintainability. For example, in the injection molding machine described in Patent Document 2, the injection device can be rotated around a support pin connecting a base and the injection device. Thereby, when checking or maintaining a nozzle for injecting melted resin, the injection device can be rotated.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, the rod for nozzle touch of the nozzle touch mechanism may also be arranged in an injection molding machine in a form where the injection cylinder extends in the horizontal direction. In this case, the plurality of rods for nozzle touch arranged in the injection molding machine are arranged at equal positions on the same circumference centered on the nozzle when viewed in the extending direction of the injection cylinder, so that the force from the rod acts evenly on the fixed die to which the mold is attached. The rod is arranged across between the injection device and the fixed die.

[0006] However, when arranging the rod for nozzle touch in an injection molding machine capable of turning the injection device, it is necessary to remove the rod arranged between the injection device and the fixed die when turning the injection device. However, removing the rod when turning the injection device is troublesome. For this reason, it has been extremely difficult to arrange the nozzle touch rod, which is the rod for nozzle touch, in an injection molding machine capable of turning the injection device without causing the trouble of attaching and detaching the rod when turning the injection device.

[0007] The present invention has been made in view of the above, and an object thereof is to provide an injection molding machine capable of turning the injection device without causing the trouble of attaching and detaching the nozzle touch rod.

Means for Solving the Problem

[0008] In order to solve the above-described problems and achieve the object, an injection molding machine according to the present invention includes an injection device that melts a resin material in an injection cylinder in which a screw is disposed inside and injects the melted resin material from a nozzle; a swivel pin that rotatably connects the injection device to a base on which the injection device is disposed; a fixed die to which a mold for molding the resin material injected from the nozzle is attached; a plurality of nozzle touch rods that are disposed in parallel with the extending direction of the injection cylinder in a state where the resin material is injected from the nozzle to the mold and one end of which is connected to the surface of the fixed die on the injection device side; and a housing that is disposed at a distance from the fixed die, to which the plurality of nozzle touch rods are connected at a position away from the fixed die, and to which the injection device is rotatably connected by a connection pin disposed on the axis of the swivel pin.

Advantages of the Invention

[0009] The injection molding machine according to the present invention has an effect that the injection device can be swiveled without causing the trouble of attaching and detaching the nozzle touch rod.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of an injection molding machine according to the present disclosure will be described in detail with reference to the drawings. Note that the present invention is not limited by these embodiments. Also, the constituent elements in the following embodiments include those that can be replaced by those skilled in the art and can be easily conceived, or those that are substantially the same.

[0012] [Embodiment] FIG. 1 is a perspective view of the main part of an injection molding machine 1 according to an embodiment. FIG. 2 is a side view of the main part of the injection molding machine 1 according to the embodiment. FIG. 3 is a plan view of the main part of the injection molding machine 1 according to the embodiment. In the following description, the vertical direction in the normal use state of the injection molding machine 1 will be described as the vertical direction Z in the injection molding machine 1, the upper side in the normal use state of the injection molding machine 1 will be described as the upper side in the injection molding machine 1, and the lower side in the normal use state of the injection molding machine 1 will be described as the lower side in the injection molding machine 1. Also, in the following description, the longitudinal direction Y of the injection molding machine 1 will be described as the longitudinal direction Y in each part having the injection molding machine 1, and the direction orthogonal to both the vertical direction Z and the longitudinal direction Y of the injection molding machine 1 will be described as the width direction X in the injection molding machine 1.

[0013] <Injection Molding Machine 1> The injection molding machine 1 according to this embodiment includes a base 5, an injection device 10 disposed on the base 5, a mold clamping device 60, and the like. The base 5 is formed in a substantially rectangular parallelepiped shape with its longitudinal direction being the longitudinal direction Y of the injection molding machine 1. On the upper surface of the base 5, a first rail 6 is disposed. Two first rails 6 are spaced apart in the width direction X on the base 5, and both of the two first rails 6 are formed to extend along the longitudinal direction of the base 5. The injection device 10 is movably placed on the first rail 6 along the extending direction of the first rail 6, and thereby the injection device 10 is movably disposed in the longitudinal direction Y.

[0014] The mold clamping device 60 is disposed on one side of the injection device 10 in the longitudinal direction Y on the base 5. The mold clamping device 60 includes a mold clamping mechanism and opens and closes a mold 63 assembled to the mold clamping mechanism. The mold clamping device 60 preferably adopts a servo motor drive system, but a hydraulic drive system may also be used.

[0015] <Injection device 10> In the following description, the side where the mold clamping device 60 is located with respect to the injection device 10 in the longitudinal direction Y is referred to as the front or the front side, and the opposite side of the side where the mold clamping device 60 is located with respect to the injection device 10 in the longitudinal direction Y is referred to as the rear or the rear side for explanation.

[0016] The injection device 10 includes a base 15, an injection cylinder 30, a screw 35 (see FIG. 4), a rotation mechanism 40 for rotating the screw 35, and a forward and backward movement mechanism 50 for moving the screw 35 forward and backward. The base 15 is a flat frame body in the vertical direction Z, and legs 16 are disposed at four positions on both sides in the longitudinal direction Y and both sides in the width direction X. The four legs 16 are movably placed on the two first rails 6 disposed on the base 5 along the extending direction of the first rail 6. Thereby, the base 15 is slidably supported with respect to the base 5 in the longitudinal direction Y.

[0017] When viewed in the vertical direction Z, the frame 20 is formed in a rectangular frame shape. Specifically, the frame 20 includes an injection bracket 21 disposed on the front side, a bearing housing 23 disposed on the rear side, and side walls 22 disposed on both sides in the width direction X of the injection bracket 21 and the bearing housing 23 and extending in the longitudinal direction Y, with both ends in the longitudinal direction Y connected to the injection bracket 21 and the bearing housing 23 respectively. The frame 20 is placed on the base 15 when the injection bracket 21 is connected to the base 15 by a swivel pin 25 (see FIG. 4) described later and the rear legs 24 formed downward from the bearing housing 23 are placed on the base 15.

[0018] The injection cylinder 30 is attached to the injection bracket 21 of the frame 20. The injection cylinder 30 extends forward in the longitudinal direction Y from the injection bracket 21, and a nozzle 31 for injecting the resin material melted in the injection cylinder 30 is disposed at the tip, i.e., the front end of the injection cylinder 30. Therefore, the injection cylinder 30 is disposed above the base 15 in the vertical direction Z and in front of the base 15 in the longitudinal direction Y.

[0019] Specifically, the injection cylinder 30 is formed in a substantially cylindrical shape and is disposed with its axial direction along the longitudinal direction Y, and a heater (not shown) such as a band heater is provided. Thereby, the injection cylinder 30 can melt the resin material inside. That is, the temperature of the injection cylinder 30 can be raised by the heater, and the resin material can be heated and melted inside to become a molten resin which is a plasticized material. The nozzle 31 is the part for injecting the resin material melted in this way from inside the injection cylinder 30 toward the front in the longitudinal direction Y.

[0020] Figure 4 is a cross-sectional view taken along line A-A of Figure 3. The screw 35 is disposed inside the injection cylinder 30 and has a spiral shape with its axial direction along the axial direction of the injection cylinder 30, that is, the screw 35 has spiral grooves on its outer peripheral surface. Thus, the screw 35 having spiral grooves is rotatable about its axis inside the injection cylinder 30. Further, the screw 35 is disposed inside the injection cylinder 30 such that the central axis of the cylinder, which is the shape of the injection cylinder 30, substantially coincides with the rotation axis of the screw 35. Moreover, the screw 35 is disposed so as to be movable in the axial direction of the injection cylinder 30. The screw 35 rotatably disposed inside the injection cylinder 30 can knead the molten resin by rotating inside the injection cylinder 30. Therefore, the injection cylinder 30 is a cylinder capable of kneading the molten resin inside.

[0021] Near the portion of the injection cylinder 30 near the side attached to the frame 20, a hopper 32 is disposed. The hopper 32 communicates with the inside of the injection cylinder 30 and can supply pellets (not shown), which are resin materials serving as raw material resins, to the injection cylinder 30.

[0022] Furthermore, on the side walls 22 located on both sides in the width direction X of the frame 20, second rails 26 (see Figures 2 and 3) are respectively disposed on the frame 20. The second rails 26 extend in the longitudinal direction Y, that is, they are formed to extend substantially parallel to the injection cylinder 30.

[0023] The rotating mechanism 40 is arranged on the rear side of the injection cylinder 30 in the longitudinal direction Y, and is capable of rotating the screw 35 arranged inside the injection cylinder 30 around the central axis. The rotating mechanism 40 for rotating the screw 35 includes a rotating mechanism main body 41, a driving electric motor 43, a transmission belt 44, and a pulley 45. Among these, the rotating mechanism main body 41 has a stay 42 (see FIG. 3) extending in the width direction X, and the stay 42 is slidably placed on the second rails 26 at two positions in the width direction X. Thereby, the rotating mechanism main body 41 is movably placed on the second rails 26 via the stay 42.

[0024] The driving electric motor 43 is arranged above the rotating mechanism main body 41. The pulley 45 is arranged in front of the rotating mechanism main body 41 and is rotatably arranged with respect to the rotating mechanism main body 41. Also, the pulley 45 is connected to the drive shaft of the driving electric motor 43 via the transmission belt 44. Thereby, the pulley 45 is capable of rotating by the driving force of the driving electric motor 43 transmitted via the transmission belt 44. In this way, the pulley 45 that can rotate by the driving force transmitted from the driving electric motor 43 is coaxially and integrally fixed to the screw 35. In other words, the rear end side of the screw 35 in the longitudinal direction Y is connected to the pulley 45. Thereby, the screw 35 arranged in the injection cylinder 30 is capable of rotating integrally with the pulley 45 by the driving force transmitted from the driving electric motor 43 to the pulley 45.

[0025] Behind the rotary mechanism main body 41 in the longitudinal direction Y, a forward and backward movement mechanism 50 is arranged. The forward and backward movement mechanism 50 can move the screw 35 arranged in the injection cylinder 30 in the axial direction of the screw 35. That is, it is possible to move the screw 35 forward or backward in the longitudinal direction Y. Specifically, the forward and backward movement mechanism 50 includes a drive motor 51 (see FIGS. 1 and 3), a transmission belt 52, a pulley 53, and a ball screw mechanism 54 (see FIG. 4). Among these, the drive motor 51 is arranged at two positions on both sides in the width direction X of the bearing housing 23 of the frame 20. The drive shafts of the drive motors 51 arranged at the two positions are respectively connected to the pulley 53 via the transmission belt 52.

[0026] The pulley 53 is rotatably supported by the bearing housing 23 of the frame 20 by a bearing (not shown). The screw portion 55 of the ball screw mechanism 54 is integrally connected to the pulley 53. The screw portion 55 of the ball screw mechanism 54 is arranged coaxially with the screw 35 and is also arranged coaxially with the pulley 45 of the rotary mechanism main body 41. The nut portion 56 of the ball screw mechanism 54 of the forward and backward movement mechanism 50 is formed in a substantially cylindrical shape, and the screw portion 55 of the ball screw mechanism 54 is screwed into the nut portion 56.

[0027] A load cell 58 is arranged between the nut portion 56 of the ball screw mechanism 54 of the forward and backward movement mechanism 50 and the rotary mechanism main body 41 of the rotary mechanism 40 in the longitudinal direction Y. The load cell 58 is arranged behind the rotary mechanism main body 41 of the rotary mechanism 40 and in front of the nut portion 56 of the ball screw mechanism 54 of the forward and backward movement mechanism 50.

[0028] The load cell 58 is a load measuring device that measures the load applied in the axial direction, and is composed of a strain generating body and a strain sensor (both not shown) attached to the strain generating body. The front surface of the load cell 58 in the longitudinal direction Y is integrally fixed to the rotating mechanism main body 41 of the rotating mechanism 40, and the rear surface in the longitudinal direction Y is integrally fixed to the nut portion 56 of the ball screw mechanism 54 of the forward and backward movement mechanism 50, and it is possible to detect the load acting in the longitudinal direction Y between the rotating mechanism main body 41 and the nut portion 56.

[0029] <Mold clamping device 60> The mold clamping device 60 (see FIG. 2) is arranged on the front side of the injection device 10 in the longitudinal direction Y, and has a fixed die 61 and a movable die 62. The fixed die 61 is arranged on the base 5 and fixed to the base 5. The movable die 62 is arranged on the side opposite to the side where the injection device 10 is located in the longitudinal direction Y with respect to the fixed die 61, and is movable in the longitudinal direction Y by a mold clamping mechanism (not shown).

[0030] A mold 63 for molding the resin material injected from the nozzle 31 is attached to the fixed die 61 and the movable die 62. The mold 63 has a fixed mold 63f attached to the fixed die 61 and a movable mold 63m attached to the movable die 62. The fixed mold 63f is attached to the surface of the fixed die 61 on the side where the movable die 62 is located, and the movable mold 63m is attached to the surface of the movable die 62 on the side where the fixed die 61 is located.

[0031] The movable mold 63m attached to the movable die 62 faces the fixed mold 63f attached to the fixed die 61, and when the movable die 62 approaches the fixed die 61, it approaches the fixed mold 63f and is combined with the fixed mold 63f. When the movable mold 63m and the fixed mold 63f are combined with each other and the mold is closed, a space corresponding to the shape of the molded product is formed between the movable mold 63m and the fixed mold 63f.

[0032] Note that the fixed mold 63f is formed with a through hole 63fp that communicates from the surface on the side opposite to the side where the movable mold 63m is located in the fixed mold 63f to the space between the movable mold 63m and the fixed mold 63f, and into which the molten resin material is injected. Further, the fixed die 61 is formed with a communication hole that longitudinally communicates in the longitudinal direction Y between the through hole 63fp formed in the fixed mold 63f and the portion on the injection device 10 side in the longitudinal direction Y.

[0033] FIG. 5 is a detailed view around the injection bracket 21 shown in FIG. 4. The injection device 10 is pivotally connected to a base 15 on which the injection device 10 is disposed by a pivot pin 25. The pivot pin 25 protrudes upward in the vertical direction Z from the upper surface of the base 15 at a position near the front end of the base 15 in the longitudinal direction Y, and is arranged such that its axial direction is the vertical direction Z. That is, the pivot pin 25 is a substantially cylindrical pin arranged such that its axial center direction is the vertical direction Z. The injection device 10 is pivotable about the pivot pin 25 with respect to the base 15 by connecting the injection bracket 21 of the frame 20 to the pivot pin 25 provided on the base 15 in this way.

[0034] Also, the injection bracket 21 of the frame 20 can be fixed in a non-pivotable state about the pivot pin 25 by a fixing screw (not shown) that fixes the frame 20 to the base 15 at positions other than where the pivot pin 25 is disposed. Therefore, the injection bracket 21 is configured to be pivotable about the pivot pin 25 with respect to the base 15 when the fixing screw is removed to release the fixing by the fixing screw.

[0035] Further, the injection molding machine 1 includes a housing 70 and a plurality of nozzle touch rods 80. The nozzle touch rod 80 is a rod-shaped member extending in the longitudinal direction Y between the mold clamping device 60 and the injection device 10, and one end thereof is connected to the surface on the injection device 10 side of the fixed die 61 included in the mold clamping device 60. That is, although the injection device 10 is rotatable about the pivot pin 25, the nozzle touch rod 80 is arranged in a direction parallel to the extending direction of the injection cylinder 30 in a state where the injection device 10 injects a resin material from the nozzle 31 of the injection device 10 into the mold 63 included in the mold clamping device 60.

[0036] FIG. 6 is a cross-sectional view taken along line B-B of FIG. 5. In the present embodiment, three nozzle touch rods 80 are arranged. When viewed in the longitudinal direction Y, the distances from the nozzle 31 of the three nozzle touch rods 80 are substantially the same in a state where the injection cylinder 30 is in a direction along the longitudinal direction Y. In other words, the three nozzle touch rods 80 are arranged on a line of a virtual circle vc centered on the center P of the nozzle 31 when viewed in the longitudinal direction Y in a state where the injection cylinder 30 is in a direction along the longitudinal direction Y.

[0037] Furthermore, the three nozzle touch rods 80 are arranged at equal intervals on the line of the virtual circle vc. In the present embodiment, among the three nozzle touch rods 80, one nozzle touch rod 80 has the same position as the nozzle 31 in the width direction X, that is, the nozzle touch rod 80 is located directly below the nozzle 31 in the vertical direction Z.

[0038] Since the three nozzle touch rods 80 are arranged at equal intervals on the line of the virtual circle vc, among the three nozzle touch rods 80, the other two nozzle touch rods 80 are located above the nozzle 31 in the vertical direction Z and are at the same position in the vertical direction Z, and are arranged on both sides of the nozzle 31 in the width direction X. For these reasons, the three nozzle touch rods 80 are respectively arranged at positions above and below the injection cylinder 30 in the vertical direction Z.

[0039] The nozzle touch rod 80 is connected to the fixed die 61 by a rod connecting portion 65 (see FIG. 5) disposed on the surface of the fixed die 61 on the side where the injection device 10 is located. The rod connecting portions 65 are disposed at three locations on the fixed die 61 corresponding to the nozzle touch rod 80, and each rod connecting portion 65 connects the nozzle touch rod 80 to the fixed die 61 so as to be relatively movable in the extending direction of the nozzle touch rod 80.

[0040] Specifically, the rod connecting portion 65 includes a case portion 66 into which the nozzle touch rod 80 enters, a pedestal portion 67 which is a portion for attaching the rod connecting portion 65 to the fixed die 61, and a spring member 68 which is a biasing member for applying a biasing force to the nozzle touch rod 80. The pedestal portion 67 is formed in a substantially rectangular plate shape with the thickness direction being the longitudinal direction Y, and one surface thereof is attached to the fixed die 61.

[0041] The case portion 66 is formed in a substantially cylindrical shape with the axial direction being the extending direction of the nozzle touch rod 80, and one end portion in the axial direction is attached to the surface of the pedestal portion 67 opposite to the surface attached to the fixed die 61. The end portion side of the case portion 66 opposite to the side attached to the pedestal portion 67 is closed by a bottom portion having a hole in the center, and the nozzle touch rod 80 is passed through the hole formed in the bottom portion. As a result, the end portion of the nozzle touch rod 80 is located inside the case portion 66.

[0042] A plate-shaped rod flange portion 85 is provided at the end portion of the nozzle touch rod 80 located inside the case portion 66 of the rod connecting portion 65. The rod flange portion 85 is a circular member with the thickness direction being the extending direction of the nozzle touch rod 80 and the diameter being slightly smaller than the inner diameter of the case portion 66.

[0043] The spring member 68 is a so-called compression spring and is disposed on the rear side in the longitudinal direction Y of the rod flange portion 85 of the nozzle touch rod 80 in the case portion 66. Thereby, the spring member 68 can apply a biasing force in the direction in which both the bottom portion of the case portion 66 and the rod flange portion 85 of the nozzle touch rod 80 move away from each other, that is, it can apply a biasing force in the front side in the longitudinal direction Y to the rod flange portion 85. In other words, the spring member 68 can apply a biasing force from the side where the injection device 10 is located in the extending direction of the nozzle touch rod 80 to the side where the fixed die 61 is located to the nozzle touch rod 80.

[0044] The housing 70 is disposed at a distance from the fixed die 61 of the mold clamping device 60 toward the injection device 10 side. Further, a plurality of nozzle touch rods 80 are connected to the housing 70 at positions away from the fixed die 61. That is, three nozzle touch rods 80 are connected to the housing 70.

[0045] Specifically, the housing 70 is provided with a portion to which three nozzle touch rods 80 are connected on a plate-like member whose thickness direction is the longitudinal direction Y, and the plate-like member portion of the housing 70 is located in the vicinity of the turning pin 25 in the longitudinal direction Y and on the rear side of the turning pin 25. The housing 70 is provided with a rod support portion 72 protruding forward in the longitudinal direction Y from the plate-like member, and the nozzle touch rod 80 is supported by the rod support portion 72.

[0046] A plurality of rod support portions 72 are provided at positions corresponding to the positions of the nozzle touch rods 80 corresponding to the nozzle touch rods 80. In the present embodiment, the rod support portions 72 are arranged at three locations of the housing 70 corresponding to the nozzle touch rods 80. These rod support portions 72 are formed in a substantially cylindrical shape with a bottom, with the axial direction being the longitudinal direction Y, the bottom side being located on the front side, and the opening side being located on the rear side. The nozzle touch rod 80 is arranged so as to penetrate through the portion that serves as the bottom in the rod support portion 72. For this reason, the nozzle touch rod 80 and the rod support portion 72, that is, the nozzle touch rod 80 and the housing 70, are capable of relative movement in the longitudinal direction Y, which is the extending direction of the nozzle touch rod 80.

[0047] Inside each rod support portion 72, a nut 82 that screws into the threaded portion 81 of the nozzle touch rod 80 is arranged. That is, on each of the plurality of nozzle touch rods 80, a threaded portion 81 is formed in a predetermined range from the rear end portion in the extending direction of the nozzle touch rod 80 toward the front side, and the nut 82 screws into the threaded portion 81 formed on the nozzle touch rod 80 in this way.

[0048] The nut 82 is arranged inside the rod support portion 72 via a bush 83 arranged between the outer peripheral surface of the nut 82 and the rod support portion 72. The nut 82 is not relatively movable in the longitudinal direction Y with respect to the rod support portion 72 and is rotatably supported by the rod support portion 72 in the rotational direction. That is, the nut 82 rotatably supported by the rod support portion 72 is rotatably supported by the housing 70 via being supported by the rod support portion 72. In this way, the nut 82 that is not relatively movable in the longitudinal direction Y with respect to the rod support portion 72 and is arranged inside the rod support portion 72 and screws into the threaded portion 81 of the nozzle touch rod 80 is capable of moving in the axial direction of the nozzle touch rod 80 integrally with the housing 70 by rotating with respect to the threaded portion 81 of the nozzle touch rod 80.

[0049] Further, a pulley 77 that is rotatable integrally with the nut 82 is attached to the nut 82. A plurality of pulleys 77 are attached to respective ones of the plurality of nuts 82. The pulley 77 is attached to the rear end portion of the nut 82 in the longitudinal direction Y, and is disposed so as to be exposed from the rod support portion 72 on the rear side of the rod support portion 72 in the longitudinal direction Y. The pulley 77 is rotatably disposed integrally with the nut 82 that rotates relative to the rod support portion 72.

[0050] FIG. 7 is a cross-sectional view taken along line C-C of FIG. 5. FIG. 8 is a cross-sectional view taken along line D-D of FIG. 5. In the present embodiment, with three nozzle touch rods 80 being used, three pulleys 77 attached to the nuts 82 corresponding to the nozzle touch rods 80 are also used. A drive motor 75 is attached to the housing 70, and a transmission belt 78 for rotating the pulleys 77 by transmitting the driving force from the drive motor 75 to each pulley 77 is wound around the three pulleys 77.

[0051] The drive motor 75 is attached to the front surface of the housing 70 in the longitudinal direction Y, and the output shaft penetrates the housing 70 in the thickness direction of the housing 70 and extends to the rear side of the housing 70 in the longitudinal direction Y. A pulley 76 is attached to the output shaft of the drive motor 75 on the rear side of the housing 70 in the longitudinal direction Y, and the transmission belt 78 is also wound around the pulley 76 attached to the output shaft of the drive motor 75.

[0052] Furthermore, an idler 79 for adjusting the path and tension of the transmission belt 78 is disposed on the rear side of the housing 70 in the longitudinal direction Y, and the transmission belt 78 is also wound around the idler 79.

[0053] As a result, the driving force generated by the drive motor 75 is transmitted from the pulley 76 attached to the output shaft to the transmission belt 78, and from the transmission belt 78 to the pulley 77 attached to the nut 82 that engages with the threaded portion 81 of the nozzle touch rod 80. Thereby, each pulley 77 is rotatable by the driving force generated by the drive motor 75.

[0054] Further, on the front surface of the housing 70 in the longitudinal direction Y, a connection pin support portion 73 that supports a connection pin 74 for connecting the housing 70 and the injection device 10 is arranged. The connection pin support portions 73 are arranged at two positions, above and below the position of the injection cylinder 30 in the vertical direction Z, and the connection pin 74 is a member having a substantially cylindrical shape and extending in the vertical direction Z.

[0055] The injection device 10 is connected to the two connection pin support portions 73 and the two connection pins 74 by the injection bracket 21. The connection pin 74 is a substantially cylindrical pin arranged in a direction such that the axial direction is the vertical direction Z, similar to the pivot pin 25. The connection pin 74 is arranged on the axis of the pivot pin 25 that pivotally connects the base 15 and the injection bracket 21, that is, on the pivot axis ax of the pivot pin 25. The injection bracket 21 is connected to the housing 70 by the connection pin 74 so as to be relatively rotatable with respect to the housing 70. In other words, the housing 70 is connected to the injection device 10 so as to be rotatable with respect to the housing 70 by the connection pin 74 arranged on the pivot axis ax of the pivot pin 25.

[0056] In the housing 70 to which the injection device 10 is connected by the connection pin 74, a through hole 71 through which the screw 35 of the injection device 10 passes is formed. The through hole 71 of the housing 70 is a hole penetrating the housing 70 in the longitudinal direction Y. The through hole 71 of the housing 70 formed in this way is a hole that is significantly larger than the diameter of the screw 35 so that when the injection device 10 rotates with respect to the housing 70 around the connection pin 74, the screw 35 does not interfere with the housing 70 from the inside of the through hole 71. In the present embodiment, the through hole 71 of the housing 70 is a circular hole whose diameter is significantly larger than the diameter of the screw 35 (see FIG. 7).

[0057] <Operation of the injection molding machine 1> The injection molding machine 1 according to the present embodiment includes the above-described configuration, and its operation will be described below. The injection molding machine 1 repeats the cycle of the injection and molding operation with one injection and molding operation as one cycle. Each cycle includes a plurality of steps for injecting the molding material and molding the product. Each cycle includes, for example, a mold closing step, a nozzle advancing step, an injection step, a metering and cooling step, a nozzle retracting step, a mold opening step, and a molded product extruding step.

[0058] The mold closing step is a step of combining the moving mold 63m and the fixed mold 63f by moving the moving die 62 of the mold clamping device 60 in a direction approaching the fixed die 61, and forming a space corresponding to the product shape between the moving mold 63m and the fixed mold 63f.

[0059] The nozzle advancing step is a step of bringing the nozzle 31 disposed at the front end of the injection cylinder 30 into contact with the fixed mold 63f of the mold clamping device 60 by moving the injection device 10 to the front side in the longitudinal direction Y.

[0060] The injection step is a step of injecting the molten resin, which is a resin material melted by the injection cylinder 30 of the injection device 10, into the space between the moving mold 63m and the fixed mold 63f attached to the mold clamping device 60.

[0061] The metering and cooling process involves waiting for a certain period of time while the temperature of the molding resin, which is a resin material injected into the space between the fixed mold 63f and the moving mold 63m attached to the mold clamping device 60, decreases and solidifies until the molding resin becomes a molded product. During this time, the molten resin to be injected in the next cycle is sent to the end side where the nozzle 31 is located in the injection cylinder 30 of the injection device 10, preparing the resin material to be used in the next cycle.

[0062] The nozzle retraction process is a process of moving the injection device 10 backward in the longitudinal direction Y to separate the nozzle 31 arranged at the end of the injection cylinder 30 from the mold 63 attached to the mold clamping device 60 to the rear side.

[0063] The mold opening process is a process of moving the moving die 62 away from the fixed die 61 in a direction to remove the molded product formed by the fixed mold 63f and the moving mold 63m attached to the mold clamping device 60, and separating the moving mold 63m from the fixed mold 63f.

[0064] The molded product extrusion process is a process of removing the molded product from the mold 63 by extruding the molded product in a state of being attached to the moving mold 63m with an extrusion device (not shown) provided in the mold clamping device 60 after separating the moving mold 63m from the fixed mold 63f.

[0065] <Operation of Injection Molding Machine 1> When molding a molded product with the injection molding machine 1, the molding of the molded product is continuously performed by repeatedly executing the cycles of these injection and molding operations. Next, the operation of the injection molding machine 1 in each of these processes will be described centering on the operation of the injection device 10.

[0066] In the nozzle forward movement process that is carried out after combining the moving die 63m and the fixed die 63f in the mold closing process, the injection device 10 is advanced by driving the driving electric motor 75. FIG. 9 is an explanatory diagram showing the state where the injection device 10 shown in FIG. 4 is advanced. When advancing the injection device 10, the driving electric motor 75 attached to the housing 70 is driven. When the driving electric motor 75 is driven, the driving force generated by the driving electric motor 75 is transmitted through the transmission belt 78 to a plurality of pulleys 77 attached to a plurality of nuts 82 arranged in the rod support portion 72, respectively. As a result, within the plurality of rod support portions 72, the plurality of nuts 82 rotate together with the pulleys 77, respectively. That is, the three pulleys 77 attached to the three nuts 82 rotate synchronously because the driving force is transmitted by one transmission belt 78, and when the three pulleys 77 rotate synchronously, the three nuts 82 also rotate synchronously.

[0067] Since each nut 82 is screwed onto the screw portion 81 of the nozzle touch rod 80, when the nut 82 rotates, the nut 82 moves along the screw portion 81 in the extending direction of the nozzle touch rod 80 as it rotates. Here, when advancing the injection device 10, the driving electric motor 75 is rotated in the direction of moving forward on the front side in the longitudinal direction Y of the nut 82 that moves in the extending direction of the nozzle touch rod 80 by the driving force generated by the driving electric motor 75 in this way. For this reason, the nut 82 that moves in the extending direction of the nozzle touch rod 80 by rotating with respect to the screw portion 81 of the nozzle touch rod 80 moves to the front side in the longitudinal direction Y.

[0068] The nut 82 is arranged within the rod support portion 72 such that it cannot move relative to the rod support portion 72 in the longitudinal direction Y, and the housing 70 can move relative to the nozzle touch rod 80 in the longitudinal direction Y. Therefore, when the nut 82 moves to the front side in the longitudinal direction Y, the housing 70 also moves relatively to the front side in the longitudinal direction Y together with the nut 82.

[0069] Since the housing 70 is connected to the injection bracket 21 of the injection device 10 by the connection pin 74, when the housing 70 moves forward in the longitudinal direction Y, the force moving forward is transmitted to the injection device 10 via the connection pin 74. Since the injection device 10 is connected to the base 15 by the swivel pin 25, when the injection device 10 moves forward in the longitudinal direction Y, the force moving forward is transmitted to the base 15 via the swivel pin 25. The base 15 to which the injection device 10 is connected by the swivel pin 25 is capable of moving in the longitudinal direction Y along the first rail 6 disposed on the base 5. Therefore, when the housing 70 moves forward in the longitudinal direction Y, the injection device 10 also moves forward in the longitudinal direction Y along the first rail 6 together with the housing 70.

[0070] Since the mold clamping device 60 is disposed on the front side of the injection device 10, when the injection device 10 moves forward in the longitudinal direction Y, the nozzle 31 located at the front end of the injection device 10 approaches the mold clamping device 60. On the extension line in the front side direction of the nozzle 31 in the mold clamping device 60, there are a communication hole that communicates the fixed die 61 in the longitudinal direction Y and the through hole 63fp of the fixed mold 63f. Therefore, when the injection device 10 moves forward in the longitudinal direction Y, the nozzle 31 passes through the communication hole formed in the fixed die 61 and contacts the portion around the through hole 63fp in the fixed mold 63f. Thereby, the nozzle 31 is in a communicating state with respect to the through hole 63fp of the fixed mold 63f.

[0071] The drive motor 75 generates a driving force in the direction of moving the injection device 10 forward for a predetermined period even after the nozzle 31 contacts the fixed mold 63f. That is, in the injection process, when injecting the molten resin from the injection device 10 into the mold 63, the nozzle 31 is pressed against the fixed mold 63f so that the injected molten resin does not leak from the gap between the nozzle 31 and the mold 63.

[0072] When a driving force in the direction of moving the injection device 10 forward is generated in the driving motor 75 with the nozzle 31 in contact with the fixed mold 63f, since the injection device 10 will no longer move forward, the nut 82 rotates by the driving force from the driving motor 75, causing the nozzle touch rod 80 to move backward.

[0073] Specifically, the nozzle touch rod 80 is connected to the fixed die 61 by a rod connecting portion 65 so as to be relatively movable in the extending direction of the nozzle touch rod 80 with respect to the fixed die 61. Further, the nozzle touch rod 80 is applied with a biasing force from the side where the injection device 10 is located to the side where the fixed die 61 is located, that is, a biasing force forward in the longitudinal direction Y, by a spring member 68 disposed at the rod connecting portion 65.

[0074] Therefore, when the driving motor 75 generates a driving force in the direction of moving the injection device 10 forward with the nozzle 31 in contact with the fixed mold 63f, the nozzle touch rod 80 moves relatively backward with respect to the housing 70 within the range where the rod flange portion 85 can move within the rod connecting portion 65 against the biasing force from the spring member 68. In this way, the driving motor 75 stops rotating when the nozzle touch rod 80 moves backward in the longitudinal direction Y against the biasing force from the spring member 68 and the spring member 68 applies a biasing force forward to the nozzle touch rod 80 via the rod flange portion 85.

[0075] Even when the rotation of the driving motor 75 stops, a force in the direction of moving forward in the longitudinal direction Y acts on the nozzle touch rod 80 due to the biasing force from the spring member 68. The force acting on the nozzle touch rod 80 is transmitted to the housing 70 via the nut 82 screwed onto the threaded portion 81 of the nozzle touch rod 80, and then transmitted from the housing 70 to the injection device 10 via the connection pin 74. As a result, since a force acts on the injection device 10 in the direction of moving it forward in the longitudinal direction Y, even when the rotation of the driving motor 75 stops, the nozzle 31 of the injection device 10 remains in a state of being pressed against the fixed mold 63f.

[0076] In this way, in the nozzle forward movement process, even when the nozzle 31 comes into contact with the fixed mold 63f and the rotation of the drive motor 75 stops, the nozzle 31 continues to be pressed against the fixed mold 63f by the biasing force applied from the spring member 68 to the nozzle touch rod 80.

[0077] In the injection process, the drive motor 51 of the forward and backward movement mechanism 50 is driven to rotate the screw portion 55 of the ball screw mechanism 54, thereby moving the nut portion 56 of the ball screw mechanism 54 that engages with the screw portion 55 to the front side in the longitudinal direction Y. As a result, the forward and backward movement mechanism 50 moves the rotation mechanism 40 to which the nut portion 56 is fixed to the front side in the longitudinal direction Y, and together with the rotation mechanism 40, moves the screw 35 forward in the injection cylinder 30. In the injection process, by moving the screw 35 forward in this way, the molten resin located in front of the screw 35 in the injection cylinder 30 is injected from the nozzle 31 into the mold 63.

[0078] In the metering and cooling process, the drive motor 43 of the rotation mechanism 40 is driven to rotate the screw 35 in the injection cylinder 30, and at the same time, the drive motor 51 of the forward and backward movement mechanism 50 is driven to move the screw 35 backward. As a result, the resin material enters from the hopper 32 into the injection cylinder 30, the resin material is melted in the injection cylinder 30, the metering of the resin material for injection in the next cycle is performed, and the melted resin material is stored in the front portion of the screw 35 in the injection cylinder 30.

[0079] Also, in the metering and cooling process, while performing the metering of the resin material in this way, it waits for a certain period of time until the resin material injected into the mold 63 in the injection process is cooled and solidified.

[0080] In the nozzle retraction process, the injection device 10 is retracted by driving the drive motor 75 in the direction opposite to the nozzle advancement process (see Fig. 4). That is, when the drive motor 75 is driven in the direction opposite to the nozzle advancement process, the nut 82 that rotates by the driving force from the drive motor 75 rotates in the direction opposite to the rotation direction during the nozzle advancement process. As a result, the nozzle touch rod 80, which the nut 82 is screwed onto the screw portion 81, moves relatively forward with respect to the nut 82. Therefore, the nozzle touch rod 80 moves to the most forward side in the longitudinal direction Y at the rod connection portion 65. That is, the nozzle touch rod 80 moves forward until the rod flange portion 85 contacts the pedestal portion 67.

[0081] Furthermore, by continuously driving the drive motor 75 in this state, the nut 82 is relatively moved to the rear side in the longitudinal direction Y with respect to the nozzle touch rod 80. As a result, the housing 70 that holds the nut 82 at the rod support portion 72 moves to the rear side in the longitudinal direction Y, and the injection device 10 connected to the housing 70 by the connection pin 74 also moves to the rear side together with the housing 70. Therefore, the nozzle 31 of the injection device 10 moves away from the fixed mold 63f attached to the fixed die 61 of the mold clamping device 60 to the rear side.

[0082] In the nozzle advancement process, when the nozzle 31 is pressed against the fixed mold 63f, the fixed mold 63f may be slightly tilted by the pressing force from the nozzle 31, and the slight tilt of the fixed mold 63f may affect the molding of the molded product. For this reason, in the nozzle retraction process, by separating the nozzle 31 from the fixed mold 63f, the force applied from the nozzle 31 to the fixed mold 63f in the nozzle advancement process can be removed. Even if the fixed mold 63f is slightly tilted, the tilt can be restored and the arrangement state of the fixed mold 63f can be adjusted.

[0083] When moving the injection device 10 backward in the nozzle retraction process and separating the nozzle 31 from the fixed mold 63f, the movable mold 63m is separated from the fixed mold 63f by moving the movable die 62 in the mold opening process, and in the molded product extrusion process, the molded product attached to the movable mold 63m is extruded to take out the molded product.

[0084] When molding a molded product by the injection molding machine 1, these operations are taken as one cycle, and by repeatedly executing these operations, the molding of the molded product is continuously performed.

[0085] <Swiveling operation of the injection device 10> Next, the swiveling operation of the injection device 10 will be described. The injection molding machine 1 according to the present embodiment can swivel the injection device 10 with respect to the base 15 around the swivel pin 25. For example, during maintenance of the injection molding machine 1, etc., the injection device 10 can be swiveled for maintenance. When swiveling the injection device 10, the injection device 10 is moved backward to position the nozzle 31 behind the fixed die 61, and further, a fixing screw (not shown) that prevents the swiveling of the injection bracket 21 around the swivel pin 25 is removed. Thereby, the swiveling of the injection bracket 21 around the swivel pin 25, that is, the swiveling of the injection device 10 with respect to the base 15, is made possible.

[0086] FIG. 10 is a plan view showing a state where the injection device 10 is swiveled around the swivel pin 25 and the connection pin 74. When the injection device 10 is in a swiveling-enabled state, the injection device 10 is swiveled with respect to the base 15 around the swivel pin 25 (see FIG. 5). The swiveling of the injection device 10 can be manually performed by an operator handling the injection molding machine 1 or can be performed using a device (not shown) that can apply a swiveling force to the injection device 10.

[0087] Here, the injection device 10 is connected to the housing 70 so as to be rotatable about the connection pin 74 disposed on the axis of the swivel pin 25 with respect to the housing 70 by the connection pin 74. For this reason, when the injection device 10 is swiveled, the injection device 10 relatively rotates with respect to the housing 70 about the connection pin 74 disposed on the axis of the swivel pin 25.

[0088] That is, even when the injection device 10 is swiveled, since the housing 70 does not swivel, when the injection device 10 is swiveled, the injection device 10 swivels with respect to the base 15 about the swivel pin 25 and relatively rotates with respect to the non - swiveling housing 70 about the connection pin 74. As a result, the injection cylinder 30 located on the front side of the position of the swivel pin 25 of the injection device 10 swivels in a direction toward the side in the width direction X of the injection molding machine 1.

[0089] At that time, since the plurality of nozzle touch rods 80 disposed across between the mold clamping device 60 and the housing 70 are arranged at positions above and below the injection cylinder 30 in the vertical direction Z, the injection device 10 can swivel without the injection cylinder 30 contacting the nozzle touch rods 80.

[0090] When the injection device 10 is swiveled with respect to the base 15 and the housing 70 about the swivel pin 25 and the connection pin 74 such that the injection cylinder 30 swivels in a direction toward the side in the width direction X, the nozzle 31 located at the front end of the injection cylinder 30 is in a state of being located outside in the width direction X than the position of the nozzle touch rods 80. As a result, an operator handling the injection molding machine 1 can easily check the state of the nozzle 31, and thus can perform maintenance such as checking for clogging of the nozzle 31 and cleaning. Further, when the injection device 10 is swiveled, since the entire injection cylinder 30 moves toward the side in the width direction, maintenance such as cleaning and replacement of the injection cylinder 30 and the screw 35 can be performed.

[0091] <Effects of the Embodiment> The injection molding machine 1 according to the above-described embodiment includes a swivel pin 25 that rotatably connects the injection device 10 to the base 15, and a housing 70 to which the injection device 10 is rotatably connected by a connection pin 74 disposed on the axis of the swivel pin 25. The housing 70 has a plurality of nozzle touch rods 80 connected thereto at a position away from the fixed die 61. That is, the nozzle touch rods 80 are not directly connected to the injection device 10 but are connected to the housing 70, and the injection device 10 is rotatably connected to the housing 70 about a connection pin 74 disposed on the axis of the swivel pin 25. Thus, when the injection device 10 is swiveled with respect to the base 15, the injection device 10 can be swiveled with the nozzle touch rods 80 attached thereto by rotating the injection device 10 with respect to the housing 70 without detaching the nozzle touch rods 80. As a result, the injection device 10 can be swiveled without the trouble of attaching and detaching the nozzle touch rods 80.

[0092] Further, the plurality of nozzle touch rods 80 are rotated by a driving force from a driving motor 75 transmitted via a transmission belt 78 by a plurality of pulleys 77 attached to nuts 82 that are screwed onto respective threaded portions 81. As the nuts 82 rotate together with the pulleys 77, the plurality of nuts 82 rotate at the same rotational speed. Thus, since the plurality of nuts 82 screwed onto the threaded portions 81 of the plurality of nozzle touch rods 80 move at the same speed in the extending direction of the nozzle touch rods 80, the housing 70 holding the nuts 82 can be moved in the longitudinal direction Y, and the injection device 10 can be moved in the longitudinal direction Y together with the housing 70. As a result, the injection device 10 can be easily moved in the longitudinal direction Y, and the nozzle 31 can be easily advanced and retracted.

[0093] Further, the nozzle touch rod 80 is biased from the side where the injection device 10 is located toward the side where the fixed die 61 is located by a spring member 68 provided in a rod connecting portion 65 that connects the nozzle touch rod 80 to the fixed die 61. Therefore, when the nozzle 31 is brought into contact with the fixed mold 63f, the housing 70 and the injection device 10 are also biased in the same direction via the nozzle touch rod 80. As a result, when the nozzle 31 is brought into contact with the fixed mold 63f, the nozzle 31 can be more reliably pressed against the fixed mold 63f. As a result, leakage of the resin material when injecting the resin material from the injection device 10 into the mold 63 can be more reliably suppressed.

[0094] Further, since the plurality of nozzle touch rods 80 are arranged at positions above and below the injection cylinder 30, when the injection device 10 is pivoted about the pivot pin 25, the injection cylinder 30 can be pivoted without contacting the nozzle touch rod 80. As a result, the injection device 10 can be pivoted more reliably without causing the trouble of attaching and detaching the nozzle touch rod 80.

[0095] Further, the three nozzle touch rods 80 are arranged at equal intervals on a line of a virtual circle vc centered on the center P of the nozzle 31 when viewed in the longitudinal direction Y. For this reason, even when the force in the extending direction of the nozzle touch rod 80 acting on the nozzle touch rod 80 is transmitted to the fixed die 61 via the rod connecting portion 65 when the injection device 10 is advanced or retracted, it is transmitted evenly from the three nozzle touch rods 80. Thereby, it is possible to suppress the fixed die 61 from falling down due to an unbalanced force acting in the longitudinal direction Y, and it is possible to suppress the fixed mold 63f and the movable mold 63m from being slightly displaced and combined in the mold closing process. As a result, the fixed mold 63f and the movable mold 63m can be combined with high accuracy, and a molded product can be molded with high accuracy.

[0096] [Modification Example] In the above-described embodiment, three nozzle touch rods 80 are provided, but the number of nozzle touch rods 80 may be different. When moving the injection device 10 in the longitudinal direction Y by rotating the nut 82 that engages with the threaded portion 81 of the nozzle touch rod 80, the force acting on the fixed die 61 from the nozzle touch rod 80 becomes uniform, and when rotating the injection device 10 with respect to the housing 70, as long as it is arranged at a position where it does not contact the injection device 10, the number and arrangement position thereof do not matter.

[0097] Also, in the above-described embodiment, the nut 82 is screwed onto the threaded portion 81 of the nozzle touch rod 80, and the driving force generated by the driving motor 75 is used to rotate the nut 82 using the transmission belt 78 and the pulley 77, thereby moving the injection device 10 in the longitudinal direction Y. However, the configuration for moving the injection device 10 in the longitudinal direction Y may be different. For example, a driving motor may be provided for each nozzle touch rod 80, and the nut 82 that engages with the threaded portion 81 of each nozzle touch rod 80 may be configured to be rotated by an individual driving motor, and the plurality of nuts 82 may be rotated synchronously by adjusting the driving timing of the plurality of driving motors. As long as the housing 70 can be moved in the longitudinal direction Y with respect to the nozzle touch rod 80 so that the injection device 10 can be moved in the longitudinal direction Y, the configuration does not matter.

[0098] Also, in the above-described embodiment, one cycle of the injection molding machine 1 performing the injection and molding operation includes a nozzle forward movement step and a nozzle backward movement step. However, when the injection molding machine 1 performs the injection and molding operation, it is not necessary to move the injection device 10 in the longitudinal direction Y every cycle. After the nozzle 31 is brought into contact with the fixed mold 63f by moving the injection device 10 forward in the longitudinal direction Y, the injection and molding operation cycles may be performed a plurality of times while keeping the nozzle 31 in contact with the fixed mold 63f.

Explanation of Reference Numerals

[0099] 1... Injection molding machine, 5... Base, 6... First rail, 10... Injection device, 15... Base, 16... Legs, 20... Frame, 21... Injection bracket, 22... Side wall, 23... Bearing housing, 24... Rear leg, 25... Swivel pin, 26... Second rail, 30... Injection cylinder, 31... Nozzle, 32... Hopper, 35... Screw, 40... Rotating mechanism, 41... Rotating mechanism main body, 42... Stay, 43... Driving motor, 44... Transmission belt, 45... Pulley, 50... Forward and backward movement mechanism, 51... Driving motor, 52... Transmission belt, 53... Pulley, 54... Ball screw mechanism, 55... Screw part, 56... Nut part, 58... Load cell, 60... Mold clamping device, 61... Fixed die, 62... Moving die, 63... Mold, 63f... Fixed mold, 63fp... Through hole, 63m... Moving mold, 65... Rod connecting part, 66... Case part, 67... Pedestal part, 68... Spring member, 70... Housing, 71... Through hole, 72... Rod support part, 73... Connecting pin support part, 74... Connecting pin, 75... Driving motor, 76... Pulley, 77... Pulley, 78... Transmission belt, 79... Idler, 80... Nozzle touch rod, 81... Screw part, 82... Nut, 83... Bush, 85... Rod flange part

Claims

1. An injection device that melts a resin material in an injection cylinder where a screw is disposed inside and injects the melted resin material from a nozzle; A swivel pin that rotatably connects the injection device to a base on which the injection device is disposed; A fixed die to which a mold for molding the resin material injected from the nozzle is attached; A plurality of nozzle touch rods arranged parallel to the extending direction of the injection cylinder in a state where the resin material is injected from the nozzle to the mold, and one end of which is connected to the surface of the fixed die on the injection device side; A housing that is disposed at a distance from the fixed die, to which a plurality of the nozzle touch rods are connected at a position away from the fixed die, and to which the injection device is rotatably connected by a connection pin disposed on the axis of the swivel pin; Threaded portions formed on each of the plurality of nozzle touch rods; A plurality of nuts that are screwed onto the threaded portions of the nozzle touch rods and are rotatably supported by the housing, and move in the axial direction of the nozzle touch rods integrally with the housing by rotating with respect to the threaded portions; A plurality of pulleys that are rotatable integrally with the nuts and are attached to each of the plurality of nuts; A driving electric motor attached to the housing; A transmission belt that is wound around the plurality of pulleys and transmits a driving force from the driving electric motor to each pulley to rotate the pulley; An injection molding machine characterized by comprising the above.

2. The injection molding machine according to claim 1, further comprising a rod connecting portion that connects the nozzle touch rod to be relatively movable in the extending direction of the nozzle touch rod with respect to the fixed die, wherein the rod connecting portion has a biasing member that applies a biasing force from the side where the injection device is located to the side where the fixed die is located in the extending direction of the nozzle touch rod to the nozzle touch rod.

3. The injection molding machine according to claim 1 or 2, wherein the plurality of nozzle touch rods are arranged at positions above and below the injection cylinder.

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