Injection molding machine

Abstract

An injection molding machine capable of improving the ease of maintenance work is provided. [Solution] The injection molding machine 1 of this invention is one that injects molding material into a mold 104 to perform molding, and is equipped with a mold support member 41 that supports the mold 104, and the mold support member 41 has one or more heat transfer medium flow paths P1, P2 that communicate with a mold side flow path and through which a heat transfer medium that adjusts the temperature of the mold 104 flows, and the inlet and outlet of at least one of the heat transfer medium flow paths P1, P2 are located on one of the two sides of the mold support member 41 that are separated by the mold 104.

Description

[Technical field]

[0001] The present invention relates to an injection molding machine having a heat transfer medium flow path for flowing a heat transfer medium within a mold when adjusting the temperature of the mold in a mold unit during injection molding. [Background technology]

[0002] When molding by injecting a molding material into a mold device, it is necessary to adjust the temperature of the mold of the mold device to an appropriate temperature in each process. For this reason, the mold of the mold device is formed with a mold-side flow path through which a heat transfer medium such as oil, water, or other liquid flows.

[0003] On the other hand, in an injection molding machine, a heat transfer medium flow path communicating with a mold side flow path is provided in a mold support member to which a mold is attached. The heat transfer medium flows from a temperature regulator such as an external heat exchanger into the heat transfer medium flow path of the mold support member of the injection molding machine, passes through the mold side flow path of the mold, and then flows out of the mold support member of the injection molding machine and flows to the temperature regulator to circulate.

[0004] As an example, in injection blow molding, an injection molding machine equipped with a rotating shaft serving as the above-mentioned mold support member that supports and rotates an intermediate mold placed between a fixed mold and a movable mold, a so-called injection blow molding machine, may be used. An example of this type of injection molding machine is described in Patent Document 1. The rotating shaft may be provided with a heat transfer medium flow path that communicates with the mold-side flow path of the intermediate mold. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-167579 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the mold support member as described above, the inlet of the heat transfer medium flow path may be provided on one of the two sides separated by the mold, and the outlet of the heat transfer medium flow path may be provided on the other of the two sides.

[0007] In this case, when performing maintenance on the heat medium flow path, work needs to be performed on both sides where the outlet and the outlet are located, and it is difficult to say that the workability is good.

[0008] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to solve such problems, and to provide an injection molding machine capable of improving the ease of maintenance work. [Means for solving the problem]

[0009] One injection molding machine that can solve the above-mentioned problems is one that injects a molding material into a mold to perform molding, and is equipped with a mold support member that supports the mold, the mold support member has one or more heat medium flow paths that communicate with a mold-side flow path and through which a heat medium that adjusts the temperature of the mold flows, and at least one of the heat medium flow paths has an inlet and an outlet on one of the two sides of the mold support member that are separated by the mold. Effect of the Invention

[0010] According to the above-described injection molding machine, the ease of maintenance work can be improved. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing an injection molding machine according to an embodiment of the present invention. [Diagram 2] 2 is a front view of an intermediate mold, an intermediate mold support frame, and a rotating shaft portion, illustrating a flow of a heat medium for adjusting the temperature of the intermediate mold in a mold device in the injection molding machine of FIG. 1. [Diagram 3] 1 is a front view of an intermediate mold, an intermediate mold support frame, and a rotating shaft portion, illustrating a flow of a heat medium for adjusting the temperature of the intermediate mold of a mold device in an injection molding machine of a reference example. FIG. [Figure 4] 4 is a cross-sectional view taken along the axial direction of the rotating shaft portion, showing one end side of the rotating shaft portion in FIG. 3 and one end side of a modified example thereof. [Diagram 5] FIG. 11 is a cross-sectional view taken along the axial direction of a rotating shaft portion, showing one end side of the rotating shaft portion provided in an injection molding machine of another embodiment. [Figure 6] 6 is a similar cross-sectional view showing a state in which the shaft body is displaced in the axial direction at one end side shown in FIG. 5. FIG. [Figure 7] 13 is a cross-sectional view taken along the axial direction of a rotating shaft portion, showing one end side of the rotating shaft portion provided in an injection molding machine of still another embodiment. FIG. [Figure 8] 2A and 2B are a partially enlarged side view and a cross-sectional view taken along line II-II of FIG. 1, showing a mold open state of a mold device attached to the injection molding machine 1 of FIG. [Figure 9] 2A and 2B are a partially enlarged side view and a cross-sectional view taken along line II-II of the mold clamping state of a mold device attached to the injection molding machine 1 of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The injection molding machine 1 illustrated in FIG. 1 generally comprises an injection device 21 that melts molding material and injects it into a mold device 101 by rotating and advancing a screw 23 arranged inside and heating it with a heater 24 arranged around it, a moving device 26 that moves the injection device 21 forward and backward relative to the mold device 101, and a mold clamping device 31 that has a fixed platen 32a, a movable platen 32b, and an intermediate mold support frame 32c, and opens and closes the mold device 101 between a mold clamping state and a mold open state.

[0013] This injection molding machine 1 may also be referred to as an injection blow molding machine, and is used for injection blow molding, in which molding material is injected into an injection molding cavity to mold a preform, and then a fluid such as gas is supplied to the preform in the blow molding cavity to expand the preform, thereby producing a molded product.

[0014] The mold apparatus 101 that defines the injection molding cavity and the blow molding cavity in a clamped state has a fixed mold 102, a movable mold 103, and an intermediate mold 104 that is placed between the fixed mold 102 and the movable mold 103. In the clamped state, the injection molding cavity is defined between the fixed mold 102 and the intermediate mold 104, and the blow molding cavity is defined between the movable mold 103 and the intermediate mold 104.

[0015] In such a mold apparatus 101, the fixed mold 102 is attached to the fixed platen 32a side, and the movable mold 103 is attached to the movable platen 32b side. An intermediate mold 104 of the mold apparatus 101 is attached to a rotating shaft portion 41, which is a mold supporting member provided on the intermediate mold support frame 32c, and is rotated by the rotating shaft portion 41. Details of the mold clamping unit 31 having the fixed platen 32a, the movable platen 32b, and the intermediate mold support frame 32c will be described later.

[0016] (Heat medium flow path) It is necessary for molds such as the intermediate mold 104 of the mold device 101 to be adjusted to an appropriate temperature in each step of injection molding using the injection molding machine 1. For this reason, the intermediate mold 104 is provided with a mold-side flow path that allows a heat medium such as oil, water, or other liquid for heating, sent from the injection molding machine 1 side to flow and returns the heat medium to the injection molding machine 1 side after flowing.

[0017] On the other hand, on the injection molding machine 1 side, one or more, for example two heat medium flow paths P1, P2 are provided on the rotating shaft part 41 to which the intermediate mold 104 is attached and which supports the intermediate mold 104, as indicated by solid and dashed arrows in Fig. 2. The heat medium flow path provided on the rotating shaft part 41 functions to send the heat medium adjusted to a predetermined temperature by a temperature regulator such as an external heat exchanger (not shown) to the above-mentioned mold-side flow path of the intermediate mold 104, and to circulate the heat medium after passing through the mold-side flow path and return it to the temperature regulator.

[0018] Although the fixed mold 102 and the movable mold 103 other than the intermediate mold 104 of the mold device 101 may also be provided with a heat medium passage, the following description focuses on the heat medium passages P1 and P2 that pass the heat medium through the intermediate mold 104 among the molds of the mold device 101 as an example. In this embodiment, the mold support member having the heat medium passage is the rotating shaft 41 provided in the injection molding machine 1 as an injection blow molding machine. However, the present invention can also be applied to a heat medium passage provided in a mold support member other than the rotating shaft 41, for example, a mold support member provided in an injection molding machine other than an injection blow molding machine, although not shown in the drawings.

[0019] The rotating shaft portion 41 having the heat medium flow paths P1 and P2 extends in an axial direction (left-right direction in FIG. 2) parallel to the mold width direction here, and has both end portions 42a and 42b that protrude in the axial direction to the outside of the intermediate mold 104. Each of the both end portions 42a and 42b is rotatably supported by a bearing or the like with respect to the intermediate mold support frame 32c, and protrudes further outward in the axial direction than the intermediate mold support frame 32c.

[0020] Here, as in the reference example shown in Fig. 3, it is also conceivable to arrange the inlet and outlet of the heat medium flow paths P1 and P2 at both ends 242a and 242b of the rotating shaft part 241 on both sides separated by the intermediate mold 104. As a result, the heat medium flow paths P1 and P2 in Fig. 3 are provided so as to extend across both ends 242a and 242b. More specifically, the heat medium flow paths P1 and P2 allow the heat medium flowing in from the inlet provided at one end 242a or the other end 242b of the rotating shaft part 241 to flow at the one end 242a side or the other end 242b side, pass through the mold side flow path, and then flow at the other end 242b side or the one end 242a side, and flow out from the outlet provided at the other end 242b or the one end 242a.

[0021] 3, when performing maintenance on each of the heat medium flow paths P1, P2, it is necessary to dismantle both end portions 242a, 242b of the injection molding machine and perform work such as cleaning the heat medium flow paths P1, P2 on both sides where the end portions 242a, 242b are located. Therefore, it is difficult to say that the workability is good in this reference example.

[0022] In contrast, in this embodiment, as shown in FIG. 2, the heat medium flow paths P1, P2 are provided so that the outlet and outlet of each heat medium flow path P1, P2 are located at one end 42a of both end ends 42a, 42b on either side of the intermediate die 104 of the rotating shaft portion 41.

[0023] According to this, the maintenance work of each of the heat medium flow paths P1, P2 can be performed only on one side of the injection molding machine 1, that is, the side where the inlet and outlet of the heat medium flow path P1, P2 are located, thereby improving the efficiency of the maintenance work.

[0024] In the illustrated example, all the inlets and outlets of the heat medium flow paths P1, P2 are located at one end 42a. When all the inlets and outlets of the heat medium flow paths P1, P2 are located at one end 42a in this manner, for example, it is possible to arrange a rotary motor or other rotary drive mechanism for the intermediate die 104 at the other end 42b, and to realize a compact device. This rotary drive mechanism can be provided at the one end 42a where the inlets and outlets of the heat medium flow paths P1, P2 are located, but in this case, the amount of protrusion of the one end 42a becomes large, so it is preferable to provide it at the other end 42b. However, when there are a plurality of heat medium flow paths, it is sufficient that the inlet and the outlet of at least one of the heat medium flow paths are located on one side. This can improve the workability of maintenance of the heat medium flow path having the inlet and the outlet on one side. The other heat medium flow paths may have an inlet on one side and an outlet on the other side. In addition, when a plurality of heat medium flow paths are provided, the inlet and outlet of a specific heat medium flow path may be provided on the opposite side to the inlet and outlet of another heat medium flow path. In other words, when looking at one heat medium flow path, it is sufficient that both the inlet and outlet of that heat medium flow path are present on either one of the two sides separated by the mold.

[0025] At least the inlet and outlet of the heat medium flow paths P1, P2 are provided at one end 42a, but flow path portions of the heat medium flow paths P1, P2 other than the inlet and outlet may be located at the other end 42b. Furthermore, of both ends 42a, 42b of the rotating shaft 41, the ends at which the inlets and outlets of the heat medium flow paths P1, P2 are provided may be interchanged with those shown in the figure. Of the ends 42a and 42b referred to here, the inlets and outlets of the heat medium flow paths P1, P2 may be provided on the end 42b side, and the above-mentioned rotation drive mechanism may be provided on the end 42a. The inlet and outlet of the heat transfer medium flow paths P1, P2 are not limited to being located at the end 42a, but can also be located on one of the two sides of the rotating shaft portion 41 separated by the intermediate mold 104, further inward in the mold width direction than the end 42a.

[0026] 2, the heat medium flow paths P1, P2 each have an inlet and an outlet provided at one end 42a of the rotating shaft 41, inlet-side flow paths P1in, P2in that make the heat medium flow from the inlet to the one end 42a and lead it to the die-side flow path of the intermediate die 104, and outlet-side flow paths P1оut, P2оut that make the heat medium that has passed through the die-side flow path flow at the one end 42a and lead it to the outlet. The heat medium that flows out of the rotating shaft 41 at the outlet is sent to an external temperature regulator and adjusted to a predetermined temperature, and then flows into the rotating shaft 41 from the inlet and circulates between them.

[0027] When the die support member is a rotating shaft portion 41, in order to provide the heat transfer medium flow paths P1, P2 on one end 42a side of the rotating shaft portion 41, the one end 42a can have a structure as shown in the cross-sectional view of FIG. 4(a) or (b), for example. The rotating shaft portion 41 has a shaft main body portion 43 that extends between both ends 42a, 42b and is driven to rotate. In addition, in FIG. 4(a) and (b), annular portions 44a to 44d that constitute at least a part of the inlet-side flow paths P1in, P2in and the outlet-side flow paths P1out, P2out of the heat transfer medium flow paths P1, P2 are provided around the shaft main body portion 43 on the one end 42a side of the rotating shaft portion 41.

[0028] Each annular portion 44a to 44d is formed at a different axial position from the other at one end portion 42a, and between them, although not shown, a rotating shaft sealing member such as an O-ring can be provided to prevent leakage of the heat transfer medium.

[0029] In this embodiment, the rotating shaft portion 41 has two heat medium flow paths P1, P2, and therefore, at one end portion 42a, a total of four annular portions 44a-44d for the inlet-side flow path portions P1in, P2in and the outlet-side flow path portions P1out, P2out of each heat medium flow path P1, P2 are arranged side by side in the axial direction at one end portion 42a. However, the number of heat medium flow paths may be one or three or more, and the number of annular portions may change accordingly.

[0030] In order to define the annular portions 44a to 44d at one end 42a of the rotating shaft portion 41, the one end 42a has an inner flow passage partition member 45a fixed to the shaft main body portion 43, and a cylindrical outer flow passage partition member 45b arranged to surround the periphery of the inner flow passage partition member 45a. When the rotating shaft portion 41 is driven to rotate, each of the annular portions 44a to 44d is defined between the inner flow passage partition member 45a which rotates together with the shaft main body portion 43 and the outer flow passage partition member 45b which is fixed to the intermediate mold support frame 32c or the like on its outer circumferential side and is stationary.

[0031] Although not shown in detail, the outer flow passage partition member 45b is provided with flow passage portions that connect the annular portions 44a to 44d to the piping members 46 that are provided on the outer periphery of the outer flow passage partition member 45b and serve as inlets or outlets. In addition, the inner flow passage partition member 45a and the shaft main body 43 are provided with flow passage portions that connect the annular portions 44a to 44d to the mold-side flow passages.

[0032] However, due to the provision of the above-mentioned rotary shaft seal member between the annular parts 44a-44d in the axial direction, the annular parts 44a-44d may have different circumferential lengths. In the illustrated embodiment, the annular parts located on the outer side of the axial direction among the multiple annular parts 44a-44d have a longer circumferential length than the annular parts located on the inner side of the axial direction. In other words, the multiple annular parts 44a-44d have the longer circumferential lengths in the order of the innermost annular part 44d in the axial direction, the annular part 44c adjacent to the innermost annular part 44c, the annular part 44b adjacent to the innermost annular part 44c, and the outermost annular part 44a. The circumferential lengths refer to the lengths measured on the central axis of the flow passage passing through the center of the flow passage cross section of the annular parts 44a-44d perpendicular to the flow direction of the heat medium.

[0033] The annular portions 44a to 44d having different circumferential lengths can be formed by forming the outer peripheral surface of the inner passage partition member 45a and the inner peripheral surface of the outer passage partition member 45b into a stepped shape in which the outer diameter or the inner diameter increases toward the outside in the axial direction. At one end 42a, a cylindrical cover member 49 with a bottom is attached to the axially outer side of the outer passage partition member 45b, covering the axial outer end surface of the outer passage partition member 45b. In FIG. 4(a), the annular portion 44a located at the outermost position in the axial direction is connected to the inside of the cover member 49 located further outside, and the inside of the cover member 49 is also filled with the heat medium flowing through the outlet side passage portion P2оut of the heat medium passage P2. On the other hand, in FIG. 4(b), the annular portion 44a is sealed by the end surface of the cylindrical cover member 49a with a bottom, and the heat medium does not flow into the inside of the cover member 49a.

[0034] In this case, for example, when the power of the thermoregulator is turned on and a heat medium such as a heat medium flows through the heat medium flow paths P1 and P2 under the action of a required internal pressure, in FIG. 4(a), an axial force Fb toward the other end 42b in the axial direction acts on the inner flow path partition member 45a and the shaft main body 43 due to the difference between the internal pressure inside the annular part 44a and the cover member 49, which has a large volume, and the internal pressure inside the annular parts 44b to 44d, which have a smaller volume compared to the large volume, as shown by the black arrow in FIG. 4(a). As a result, the inner flow path partition member 45a and the shaft main body 43 are displaced toward the other end 42b in the axial direction. In this case, as shown in FIG. 2, of the split rings 47a and 47b located between the intermediate mold 104 and the intermediate mold support frame 32c, the split ring 47b on the other end 42b side is pressed against the intermediate mold support frame 32c and wears, and metal powder generated therein may adhere to the molded product. On the other hand, in Fig. 4(b), the internal pressure acting on the heat medium flow paths P1 and P2 generates an axial force Fa in a direction (toward one end 42a in the axial direction) that separates the inner flow path partition member 45a and the outer flow path partition member 45b, whose inner and outer diameters increase toward the outside in the axial direction, as shown by the white arrow in Fig. 4(b). As a result, the inner flow path partition member 45a and the shaft main body 43 are displaced toward the one end 42a in the axial direction by the axial force Fa. As a result, the split ring 47a on the one end 42a side shown in Fig. 2 may wear out.

[0035] To address this, in the embodiment shown in Fig. 5, a step is added to the axially outermost part of the inner flow-path partition member 45a compared to that shown in Fig. 4, and a displacement restriction member 48, such as a plate-like member, is connected to the axially outer end face of the inner flow-path partition member 45a to restrict the axial displacement of the shaft main body 43. Furthermore, the above-mentioned cover member 49 is provided axially outer than the outer flow-path partition member 45b.

[0036] This plate-like displacement restricting member 48 is located inside the cover member 49, and is disposed between the cover member 49 and the outer end surface of the outer flow path partition member 45b, particularly with its outer peripheral edge 48a protruding more radially outward than the inner flow path partition member 45a. As a result, when the inner flow path partition member 45a and the shaft main body 43 are displaced in the axial direction, the displacement restricting member 48 abuts against the cover member 49 or abuts against the outer end surface of the outer flow path partition member 45b with its outer peripheral edge 48a, thereby restricting the amount of axial displacement of the shaft main body 43 connected to the displacement restricting member 48. However, the displacement restricting member 48 is not limited to a plate-like member having an outer peripheral edge 48a abutting against the outer end surface of the outer flow path partition member 45b as shown in the figure, as long as it can restrict the amount of axial displacement of the shaft main body 43.

[0037] 5, which is caused by the internal pressure of the heat medium flow paths P1, P2 as described above, the displacement restriction member 48 comes into contact with the cover member 49, preventing further displacement of the inner flow path partition member 45a and the shaft main body 43 outward in the axial direction. As a result, wear of the split rings 47a, 47b and the associated generation of metal powder can be suppressed.

[0038] However, for example, when the temperature regulator is turned off and the temperatures of the intermediate die 104 and the rotating shaft portion 41 drop, an axial force Fb in the direction opposite to the axial force Fa and indicated by the black arrow in Fig. 6 acts on the inner flow path partition member 45a due to thermal contraction of the shaft main body portion 43. At this time, as shown in Fig. 6, if the axial force Fb continues to act even after the displacement restriction member 48 reaches a position where its outer peripheral edge portion 48a abuts against the outer end face of the outer flow path partition member 45b, there is a concern that the connection points, such as bolts, between the displacement restriction member 48 and the inner flow path partition member 45a may be damaged.

[0039] 7, the connection between the inner flow path partition member 45a and the displacement restriction member 48 includes an elastic member 50 that resists an axial force Fb that pulls the displacement restriction member 48 away from the inner flow path partition member in the axial direction. More specifically, in this example, the connection between the inner flow path partition member 45a and the displacement restriction member 48 includes a bolt 51 that penetrates the plate-shaped displacement restriction member 48 and screws into the shaft main body 43, and an elastic member 50 such as a coil spring that has a shaft portion of the bolt 51 inserted therein and is interposed between the head and the displacement restriction member 48. Note that an inner abutment member 52 is further provided, which is provided so as to match the inside of the cover member 49, has a bottomed cylindrical shape with smaller inner and outer diameters than the cover member 49, and restricts displacement by the displacement restriction member 48 between the outer flow path partition member 45b and the bolt 51.

[0040] 7, when an axial force Fa directed toward one end 42a in the axial direction is applied, as shown in Fig. 7(a), the outer peripheral edge 48a of the displacement restriction member 48 contacts the open end of the inner abutment member 52, preventing further displacement of the inner flow path partition member 45a and the shaft main body 43. The inner abutment member 52 is not limited to being cylindrical as shown in the figure, so long as it can restrict the inner flow path partition member 45a and the shaft main body 43 when the axial force Fa is applied in this manner. On the other hand, when an axial force Fb in the opposite direction to the axial force Fa acts, the displacement restriction member 48 abuts against the outer flow path partition member 45b, and when the axial force Fb is further applied, as shown in Fig. 13B, the inner flow path partition member 45a and the shaft main body 43 move away from the displacement restriction member 48, and the elastic member 50 is sandwiched between the head of the bolt 51 and the displacement restriction member 48 and deforms, thereby resisting the axial force Fb. This makes it possible to effectively suppress damage to the connection between the displacement restriction member 48 and the inner flow path partition member 45a.

[0041] In order to change the space between the inner abutment member 52 and the outer flow path partition member 45b and adjust the displacement of the shaft main body portion 43 that is regulated by the displacement regulating member 48, a shim or spacer, for example a plate-like shim (not shown), can be provided between the inner abutment member 52 and the cover member 49.

[0042] It is also possible to provide the displacement restricting member 48, the elastic member 50, and other structures as measures against the axial forces Fa and Fb on the other end 42b side. However, as described above, the rotation drive mechanism of the intermediate die 104 may be disposed on the other end 42b side, and in this case, metal powder that may be generated by wear of the structure against the axial forces Fa and Fb may enter the rotation drive mechanism. From this viewpoint, it is preferable to provide the displacement restricting member 48, the elastic member 50, and other structures on one end 41a side, as in the illustrated embodiment.

[0043] Lubricating oil can be poured into the inside of the cover member 49 (or the inside of the inner abutment member 52). This allows the displacement restricting member 48 to slide smoothly inside the cover member 49. Even if metal powder is generated inside the cover member 49 due to the sliding of the displacement restricting member 48, the metal powder is retained inside, and therefore adhesion of such metal powder to the molded product is suppressed.

[0044] (mold clamping device) The intermediate mold support frame 32c having the rotary shaft portion 41 as described above is included in the mold clamping device 31 as one of the mold holding mechanisms 32 that hold the mold device 101. In addition to the mold holding mechanism 32 having the fixed platen 32a, the movable platen 32b, and the intermediate mold support frame 32c, the mold clamping device 31 has an intermediate mold moving mechanism 61 that moves the intermediate mold support frame 32c relative to the fixed platen 32a, a mold clamping mechanism 33 that moves the movable platen 32b relative to the fixed platen 32a, and a split mold opening / closing mechanism 62 that opens and closes the split mold of the movable mold 103. The intermediate mold moving mechanism 61 and the split mold opening / closing mechanism 62 will be described later with reference to FIGS. 8 and 9.

[0045] The mold holding mechanism 32 includes a fixed platen 32a located between the injection unit 21 and the mold unit 101, a movable platen 32b located between the fixed platen 32a across the mold unit 101 and capable of moving toward and away from the fixed platen 32a, and an intermediate mold support frame 32c located between the fixed platen 32a and the movable platen 32b and capable of moving toward and away from the fixed platen 32a. The mold clamping unit 31 is also provided with one or more tie bars 32d extending from the fixed platen 32a toward a rear platen 34 (described later) and connecting the fixed platen 32a and the rear platen 34. In this example, the movable platen 32b and the intermediate mold support frame 32c are guided by the tie bars 32d in their moving toward and away from the fixed platen 32a, but there are also cases where they are not guided by the tie bars 32d.

[0046] Of the mold holding mechanism 32, the fixed platen 32a is fixedly attached to the base frame 2. On the other hand, the movable platen 32b and the intermediate mold support frame 32c are each disposed on a guide member 32e laid on the base frame 2, and can slide independently of each other in a direction away from and toward the fixed platen 32a.

[0047] At a position where the movable platen 32b and the intermediate mold support frame 32c are separated from the fixed platen 32a, the movable mold 103 and the intermediate mold 104 of the mold device 101 are in a mold open state in which they are open from the fixed mold 102. By moving the movable platen 32b and the intermediate mold support frame 32c toward the fixed platen 32a from this separated position, the movable mold 103 and the intermediate mold 104 are in a mold closed state in which they are closed against the fixed mold 102, and by further moving the movable platen 32b and the intermediate mold support frame 32c toward the fixed platen 32a, the movable mold 103 and the intermediate mold 104 are in a mold clamped state in which they are pressed against the fixed mold 102. Here, the direction in which the fixed mold 102 of the mold device 101 approaches the fixed platen 32a to which it is attached is referred to as the front side, and the direction in which it moves away from the fixed platen 32a is referred to as the rear side. For most parts of the mold clamping unit 31 except for the fixed platen 32a, the right side in FIG. 1, approaching the fixed platen 32a, is the front side, and the left side, away from the fixed platen 32a, is the rear side.

[0048] The illustrated intermediate mold support frame 32c has a frame shape such as a rectangle when viewed from the front, as shown in Fig. 2, and is provided with a rotating shaft portion 41 that is rotatably arranged and extends in the mold width direction (left-right direction in Fig. 2) perpendicular to the front-rear direction in a plane parallel to the horizontal plane. The rotating shaft portion 41 is also called a mold support member because it supports the intermediate mold 104 attached thereto. In this example, the axial direction of the rotating shaft portion 41 is parallel to the horizontal direction, but the axial direction of the rotating shaft portion is not limited to this, and may be parallel to the vertical direction, for example.

[0049] Further, the intermediate mold support frame 32c is provided with an intermediate mold rotation mechanism that rotates mainly the shaft body portion 43 of the rotating shaft portion 41 and rotates the intermediate mold 104 therewith. Although not shown, this intermediate mold rotation mechanism can be provided, for example, on the other end 42b side of the aforementioned one end 42a and the other end 42b of the rotating shaft portion 41. As described above, this can be realized by concentrating the heat medium flow paths P1, P2 for adjusting the temperature of the intermediate mold 104 on the one end 42a side.

[0050] The intermediate mold moving mechanism 61 that moves the intermediate mold support frame 32c relative to the fixed platen 32a can be configured with hydraulic cylinders 61a and piston rods 61b that are attached to the fixed platen 32a and the intermediate mold support frame 32c, respectively, and operated by a hydraulic pump driven by a motor, as shown in Figures 8 and 9. In this example, two pairs of hydraulic cylinders and piston rods are provided that are located outside the fixed mold 102 and the intermediate mold 104 in the mold width direction, but one pair or three or more pairs may be provided. Although not shown in the figures, the intermediate mold moving mechanism may move the intermediate mold support frame relative to the movable platen by attaching hydraulic cylinders or the like to the movable platen instead of the fixed platen.

[0051] As shown in FIG. 1, the clamping mechanism 33 of the clamping device 31 includes a rear platen 34 arranged on the base frame 2, a clamping motor 35 provided on the rear platen 34, a motion conversion mechanism 36 that converts the rotational motion of the clamping motor 35 into linear motion in the displacement direction of the movable platen 32b, and a toggle mechanism 37 that amplifies the force transmitted to the motion conversion mechanism 36 and transmits it to the movable platen 32b.

[0052] Among these, the motion conversion mechanism 36 can be various mechanisms capable of converting rotary motion into linear motion, but in this example, it is configured to include a screw shaft 36a rotated by the mold clamping motor 35 and a nut 36b screwed onto the screw shaft 36a. The motion conversion mechanism 36 can also be a ball screw. The toggle mechanism 37 for increasing the transmission force from the motion conversion mechanism 36 is formed by connecting a plurality of links 37a to 37c connecting the nut 36b of the motion conversion mechanism 36 and the movable platen 32b with joints so as to be swingable. The number and shapes of the links and joints can be appropriately changed, but as shown in FIG. 1, a pair of link groups consisting of the links 37a to 37c located above and below the crosshead 37d are swingably connected to a crosshead 37d connected to the nut 36b and extending in the vertical direction.

[0053] In addition to the above-mentioned mold clamping motor 35, a mold thickness adjustment motor 38 can also be provided on the rear platen 34. This mold thickness adjustment motor 38 functions to adjust the interval between the fixed platen 32a and the rear platen 34 movably mounted on the base frame 2 by applying a rotational driving force to a screw shaft and a nut connected to an extension portion of each tie bar 32d of the above-mentioned mold holding mechanism 32. This makes it possible to adjust the mold thickness so that a desired mold clamping force can be applied to the mold device 101 even when the mold device 101 is replaced or the thickness of the mold device 101 is changed due to a temperature change. Although not shown in the figure, the mold thickness can be adjusted even if the fixed platen side is made movable on the base frame 2 and the rear platen side is fixed.

[0054] As shown in Figures 8 and 9, the mold clamping device 31 is equipped with a split mold opening / closing mechanism 62 which has a piston rod 62a, a hydraulic cylinder 62b, etc., and drives the split mold of the movable mold 103 back and forth in the mold width direction to open and close it.

[0055] The illustrated mold clamping unit 31 is of a horizontal type in which the moving direction of the movable platen 32b is parallel to the horizontal direction, but it may also be of a vertical type in which the moving direction is vertical.

[0056] (injection device) The injection device 21 mainly includes a cylinder 22 having a cylindrical shape or the like extending toward the mold device 101, a screw 23 arranged inside the cylinder 22 with its central axis parallel to the cylinder 22 and with flights spirally provided around it, a heater 24 having a band shape or the like arranged around the outer periphery of the cylinder 22, and a motor box 25 arranged behind the cylinder 22 and the screw 23. Although not shown in the figure, the motor box 25 includes a metering motor that rotates the screw 23 around the central axis to accumulate a predetermined amount of molding material at the tip of the cylinder 22, an injection motor that moves the screw 23 forward and backward in each direction, toward and away from the mold device 101, and a pressure detection sensor that detects the pressure that the screw 23 receives from the molding material, and the like.

[0057] In this case, the direction approaching the fixed platen 32a of the mold clamping unit 31 to which the fixed mold 102 of the mold apparatus 101 is attached is defined as the front side, and the direction moving away from the fixed platen 32a is defined as the rear side. Therefore, when looking at the injection unit 21 located to the right of the fixed platen 32a in Fig. 1, the left direction approaching the fixed platen 32a is the front side, and the right direction moving away from the fixed platen 32a is the rear side.

[0058] The cylinder 22 is provided with a supply port 22a, to which a hopper for feeding molding material into the cylinder 22 can be attached, in front of the motor box 25 on the rear side. A nozzle 22b, the cross-sectional area of ​​which decreases on the front side, is provided at the tip of the cylinder 22 close to the mold device 101. A water-cooled cylinder 22c for cooling with water or the like can be provided near the supply port 22a.

[0059] The heater 24 disposed around the cylinder 22 including the nozzle 22b may be divided into a plurality of parts in the cylinder axial direction as shown in the figure, so that the inside of the cylinder 22 inside each heater part can be heated at different temperatures. Each heater part may be provided with a temperature detector.

[0060] A backflow prevention ring (not shown) may be disposed around a constricted portion formed by partially reducing the outer diameter of the tip of the screw 23 to prevent the molding material, which has been sent forward and backward together with the screw 23, from flowing backward toward the rear. This backflow prevention ring displaces back and forth relative to the screw 23 in response to the pressure it receives from molding material located forward or backward from it, thereby allowing only the flow of molding material from the rear to the front.

[0061] According to the injection device 21 having such a configuration, the molding material fed into the inside of the cylinder 22 from the supply port 22a is heated by the heater 24 on the outer periphery of the cylinder 22 and melted based on the rotation of the screw 23 driven by the metering motor, while being sent forward inside the cylinder 22 and accumulated at the tip of the cylinder 22. At this time, the screw 23 is displaced backward by the injection motor to form a space at the tip of the cylinder 22 in which the molding material is accumulated.

[0062] Thereafter, by displacing the screw 23 forward, the molding material at the tip of the cylinder 22 is injected toward the mold device 101 through the nozzle 22b. Further thereafter, pressure is applied to the molding material filled in the cavity of the mold device 101 through the molding material remaining at the tip of the cylinder 22, thereby performing pressure dwell. At this time, it is possible to replenish the molding material that has become insufficient in the injection molding cavity of the mold device 101 due to cooling contraction of the molding material.

[0063] Although this injection molding machine 1 is an in-line screw type, it is also possible to make it a pre-plasticization type injection molding machine in which the plasticizing cylinder and plasticizing screw are structurally and functionally separated from the injection cylinder and injection plunger.

[0064] (Mobile device) The moving device 26 is provided, for example, below the motor box 25 of the injection device 21, and is an advance / retract drive mechanism for moving the injection device 21 forward and backward relative to the fixed platen 32a. Various mechanisms can be adopted as the forward and backward drive mechanism that constitutes the moving device 26, but the moving device 26 shown in the figure is configured to include a hydraulic pressure pump 27 or the like, a pump operation motor 28, which is electric or the like, that operates the hydraulic pump 27, and a double-acting hydraulic cylinder 29 that is supplied with hydraulic fluid from the hydraulic pump 27 and causes a piston rod, the tip of which is fixed to a fixed platen 32a, to perform an extrusion and retraction motion.

[0065] The moving device 26 further includes a slide base 26a to which the above-mentioned hydraulic pump 27, pump actuation motor 28, and hydraulic cylinder 29 are attached, and a guide 26b that is laid on the base frame 2 to guide the linear motion of the slide base 26a. This realizes forward and backward displacement of the injection device 21 placed on the upper part of the slide base 26a.

[0066] The moving device 26 makes it possible to move the injection device 21 away from the mold device 101, or to move the injection device 21 closer to the mold device 101 and press the nozzle 22b of the cylinder 22 of the injection device 21 against the mold device 101 with a predetermined pressure, thereby performing a so-called nozzle touch.

[0067] (Molding equipment) A mold assembly 101 attached to the injection molding machine 1 has a fixed mold 102, a movable mold 103, and an intermediate mold 104. In this mold assembly 101, when in a mold clamping state by the mold clamping device 31, an injection molding cavity is defined between the fixed mold 102 and the intermediate mold 104, and a blow molding cavity is defined between the movable mold 103 and the intermediate mold 104.

[0068] More specifically, as shown in Fig. 8(b), the fixed mold 102 is provided with a fixed-side concave mold portion 102a. In the mold clamping state, the convex mold portion 104a of the intermediate mold 104 is inserted and positioned in the fixed-side concave mold portion 102a, and an injection molding cavity corresponding to the shape of the preform PF is defined between the fixed-side concave mold portion 102a and the convex mold portion 104a.

[0069] The movable mold 103 has split molds 103b that can be separated in the mold width direction, and a movable-side concave mold portion 103a is provided that is defined by combining the split molds 103b (see Figs. 8(b) and 9(b)). In the mold clamped state, a blow molding cavity corresponding to the shape of the molded product MP is defined between the movable-side concave mold portion 103a and the convex mold portion 104a of the intermediate mold 104 inserted and positioned within the movable-side concave mold portion 103a. The split molds 103b of the movable mold 103 can be connected to each other by split mold connecting members 63a, 63b, which are moved in the same direction in the mold width direction by the split mold opening / closing mechanism 62.

[0070] The intermediate mold 104 is formed by providing a convex portion 104a on each surface of two core molds positioned across the rotation shaft portion 41 in the front-to-rear direction, the surface facing the fixed mold 102 or the movable mold 103.

[0071] In the illustrated example, the fixed side concave portion 102a of the fixed mold 102, the convex portion 104a of the intermediate mold 104, and the movable side concave portion 103a of the movable mold 103 are each arranged two in the mold width direction and six in the height direction (the up and down direction in Figures 8(a) and 9(a)), totaling twelve, but the numbers can be changed as appropriate.

[0072] The mold device 101 can be attached to the injection molding machine 1 or replaced as appropriate depending on the shape of the molded product to be manufactured, and is not considered to be a part of the injection molding machine 1.

[0073] (Operation of injection molding machine) The injection molding machine 1 described above operates to carry out the following steps. With the mold device 101 in the mold open state shown in Figure 8, a mold closing process is performed in which the movable platen 32b is moved toward the fixed platen 32a by the mold clamping mechanism 33, and the intermediate mold support frame 32c is moved toward the fixed platen 32a by the intermediate mold moving mechanism 61.

[0074] Next, with a predetermined amount of molding material having already been accumulated and arranged inside the injection unit 21 by measuring during the previous molding, which will be described later, a clamping process is performed in which the mold unit 101 is clamped using the clamping unit 31, as shown in Fig. 9. In the clamping process, an injection molding cavity is defined between the fixed mold 102 and the intermediate mold 104, and a blow molding cavity is defined between the movable mold 103 and the intermediate mold 104.

[0075] Then, the screw 23 advances to inject the molding material toward the injection molding cavity of the mold device 101, and the injection process is performed to fill the injection molding cavity with the molding material. In the injection process, after the injection molding cavity is filled with the molding material, the screw 23 advances further to hold the molding material inside the tip of the injection device 21 at a predetermined pressure. Thereafter, the molding material filled in the injection molding cavity is cooled and solidified. As a result, the preform PF is molded in the injection molding cavity. At this time, the molding material separately charged into the injection device 21 is melted while being sent toward the tip of the injection device 21 by the rotation of the screw 23 under heating by the heater 24, and a predetermined amount of the molding material is measured and placed at the tip.

[0076] In parallel with the above-mentioned injection process, a blowing process is carried out in the blow molding cavity. A preform PF that has already been molded in the injection molding cavity before the intermediate mold 104 is inverted is placed in the blow molding cavity. In the blowing process, a fluid such as air or other gas is supplied to the preform PF, and the preform PF is expanded in the blow molding cavity to mold a molded product MP.

[0077] Thereafter, the mold clamping mechanism 33 and the intermediate mold moving mechanism 61 of the mold clamping device 31 are operated to move the movable platen 32b and the intermediate mold support frame 32c away from the fixed platen 32a, and the mold opening process is performed to open the mold device 101.

[0078] After the mold opening step, the split mold opening / closing mechanism 62 is used to open the split mold of the movable mold 103 and remove the molded product MP, and then a split mold opening / closing step is performed in which the split mold of the movable mold 103 is closed. Also, here, an intermediate mold rotating step is performed in which the intermediate mold 104 is inverted by the intermediate mold rotating mechanism. As a result, the convex mold portion 104a of the core mold of the intermediate mold 104 on the side from which the molded product MP was collected in the split mold opening and closing step faces the fixed-side concave mold portion 102a of the fixed mold 102. On the other hand, the convex mold portion 104a of the core mold of the intermediate mold 104 on the side from which the preform PF was molded in the injection step faces the movable-side concave mold portion 103a of the movable mold 103 while holding the preform PF. The intermediate mold rotating step can be performed at approximately the same time as the split mold opening and closing step, or before or after the split mold opening and closing step.

[0079] In injection molding using the injection molding machine 1, the above-mentioned mold closing process, mold clamping process, injection process, blowing process, mold opening process, split mold opening / closing process, and intermediate mold rotating process are repeatedly performed. [Explanation of symbols]

[0080] 1 injection molding machine 2 Base frame 21 Injection device 22 cylinders 22a Supply port 22b Nozzle 22c water-cooled cylinder 23 Screw 24 Heater 25 Motor box 26 Mobile Devices 26a Slide Base 26b Guide 27 Hydraulic Pump 28 Pump operating motor 29 Hydraulic Cylinder 31 Mold clamping device 32a Fixed Platen 32b Movable platen 32c Intermediate mold support frame 32d tie bar 32e Guide member 33 Mold clamping mechanism 34 Rear platen 35 Clamping motor 36 Motion conversion mechanism 36a Screw shaft 36b Nut 37 Toggle Mechanism 37a~37c Link 37d Crosshead 38 Die thickness adjustment motor 41 Rotating shaft portion (mold support member) 42a One end 42b The other end 43 Shaft body 44a~44d Circular part 45a Inner flow passage partition member 45b Outer flow passage partition member 46 Piping components 47a, 47b split ring 48 Displacement control member 48a Outer periphery 49, 49a Cover member 50 Elastic member 51 Volts 52 Inner abutment member 61 Intermediate mold moving mechanism 61a Hydraulic cylinder 61b Piston rod 62 Split mold opening and closing mechanism 62a Piston rod 62b Hydraulic cylinder 63a, 63b Split type connecting member 101 Mold equipment 102 Fixed mold 102a Fixed side concave part 103 Movable mold 103a Movable side concave part 103b split mold 104 Intermediate mold (mold) 104a Convex part Fa, Fb Axial forces P1, P2 Heat transfer medium flow path P1in, P2in inlet flow path section P1оut, P2оut Outflow side flow path section PF Preform MP molded product

Claims

1. An injection molding machine that injects a molding material into a mold, A mold support member is provided to support the mold, the mold support member has one or more heat medium flow paths communicating with the mold-side flow paths and through which a heat medium for adjusting the temperature of the mold flows; At least one of the heat transfer medium flow passages has an inlet and an outlet on one of both sides of the mold support member separated by the mold, The heat transfer medium flow path is an inlet-side flow passage portion that causes the heat transfer medium to flow from the inlet to the one side and guides the heat transfer medium to a mold-side flow passage; an outlet-side flow passage portion that causes the heat transfer medium to flow from the die-side flow passage on the one side and guides the heat transfer medium to the outlet port; having The mold support member is a rotary shaft portion extending in an axial direction parallel to the mold width direction to rotate the mold, and the rotary shaft portion has a shaft main body portion extending between both end portions, the inlet-side flow path portion and the outlet-side flow path portion are each provided around the shaft main body at mutually different axial positions on the one side, the inlet-side flow path portion and the outlet-side flow path portion having portions that constitute at least a portion of each of the inlet-side flow path portion and the outlet-side flow path portion.

2. An injection molding machine that injects a molding material into a mold, A mold support member is provided to support the mold, the mold support member has one or more heat medium flow paths communicating with the mold-side flow paths and through which a heat medium for adjusting the temperature of the mold flows; At least one of the heat transfer medium flow passages has an inlet and an outlet on one of both sides of the mold support member separated by the mold, The heat transfer medium flow path is an inlet-side flow passage portion that causes the heat transfer medium to flow from the inlet to the one side and guides the heat transfer medium to a mold-side flow passage; an outlet-side flow passage portion that causes the heat transfer medium to flow from the die-side flow passage on the one side and guides the heat transfer medium to the outlet port; having The mold support member is a rotary shaft portion extending in an axial direction parallel to the mold width direction to rotate the mold, and the rotary shaft portion has a shaft main body portion extending between both end portions, The one side portion of the rotating shaft portion is an inner flow passage partition member provided in the shaft main body; An injection molding machine having an outer flow passage partition member disposed to surround the periphery of the inner flow passage partition member and defining a flow passage portion between itself and the inner flow passage partition member.

3. A plurality of the heat medium flow paths are provided, an inlet and an outlet of each of the plurality of heat transfer medium flow paths are located on one of both sides of the mold support member across the mold, 2. The injection molding machine according to claim 1, wherein the inlet-side flow passage portion and the outlet-side flow passage portion of each heat medium flow passage are arranged side by side in the axial direction on the one side.

4. An injection molding machine as described in claim 1 or 3, wherein the portions constituting at least a portion of each of the inlet side flow path portion and the outlet side flow path portion are a plurality of annular portions, and among the plurality of annular portions, the annular portions located on the axial outer side have a longer circumference than the annular portions located on the axial inner side.

5. The one side portion of the rotating shaft portion is an inner flow passage partition member provided in the shaft main body; an outer flow passage partition member that is disposed so as to surround the periphery of the inner flow passage partition member and that partitions, between the inner flow passage partition member and the outer flow passage portion, at least a portion of each of the inlet-side flow passage portion and the outlet-side flow passage portion; 5. The injection molding machine according to claim 1, 3 or 4, further comprising:

6. 6. The injection molding machine according to claim 2, wherein the rotating shaft portion has a displacement restricting member connected to an axially outer end face of the inner flow passage partition member for restricting an axial displacement amount of the shaft body portion.

7. 7. The injection molding machine according to claim 6, wherein a connection portion between the inner flow passage partition member and the displacement regulating member includes an elastic member that resists the action of an axial force in a direction that pulls the displacement regulating member away from the inner flow passage partition member in the axial direction.

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