Twin injection molding machine with two injection devices

Abstract

To provide a twin injection molding machine in which an increase in width and an increase in installation area are suppressed.SOLUTION: A twin injection molding machine (1) consists of a mold clamping device (2) and injection devices (4A, 4B). The injection device is provided with a piston cylinder unit (21) which is a moving mechanism for moving the injection device (4A) toward and away from the mold clamping device (2). The injection device (4A) has a support structure including a support plate (24A) which supports a heating cylinder (14A). On the support plate (24A), a notch (31A) through which the piston cylinder unit (21) passes is formed.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a twin injection molding machine in which two injection units are provided for a mold clamping unit. [Background technology]

[0002] An injection molding machine is equipped with a mold clamping device that clamps a mold and an injection device that injects injection material. When molding a large molded product, the injection device needs to be large in size in order to inject a large amount of injection material. However, there is a limit to how large the injection device can be. In contrast, a twin injection molding machine in which two injection devices are provided for one mold clamping device, as described in Patent Document 1, for example, is suitable for molding large molded products. This is because the injection amount can be shared between the two injection devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2-72914 Summary of the Invention [Problem to be solved by the invention]

[0004] Since a twin injection molding machine is equipped with two injection units, it requires a width equal to the width of the two injection units, which poses the problem of a large installation area.

[0005] The present disclosure provides a twin injection molding machine that suppresses an increase in width and an increase in installation area.

[0006] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0007] An injection molding machine comprises a mold clamping device and an injection device, and each injection device comprises a heating cylinder, a screw contained in the heating cylinder, and a screw drive device for driving the screw. The injection unit is provided with a piston-cylinder unit, which is a moving mechanism that moves the injection unit toward and away from the mold clamping unit. The present disclosure is configured as follows: The injection unit is provided with a support structure that supports a heating cylinder, and the support structure includes a support plate that supports the heating cylinder, and the support plate is formed with a notch through which the piston-cylinder unit passes. Effect of the Invention

[0008] According to the present disclosure, it is possible to suppress an increase in the width of a twin injection molding machine and an increase in the installation area. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a top view showing a twin injection molding machine according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a top view showing a bed on which the first and second injection units of the twin injection molding machine according to the present embodiment are placed. [Diagram 3] FIG. 1 is a top view showing a portion of a twin injection molding machine according to an embodiment of the present invention. [Figure 4] 3 is a front view showing a support plate that supports a heating cylinder and is part of the support structure according to the present embodiment. FIG. [Diagram 5] FIG. 1 is a top view showing a conventional injection molding machine. [Figure 6] FIG. 1 is a front view showing a support plate that is part of a conventional support structure, which supports a heating cylinder. [Figure 7] FIG. 11 is a top view showing a part of a twin injection molding machine according to a second embodiment of the present invention. [Figure 8] FIG. 11 is a front view showing first and second injection units in a twin injection molding machine according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Specific embodiments will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments. In order to clarify the description, the following description and drawings are appropriately simplified. In each drawing, the same elements are given the same reference numerals, and duplicated descriptions are omitted as necessary. In addition, hatching is omitted in some parts to avoid cluttering the drawings.

[0011] <Twin injection molding machine according to this embodiment> As shown in FIG. 1, the twin injection molding machine 1 according to this embodiment is composed of one mold clamping unit 2 and first and second injection units 4A and 4B. The first and second injection units 4A and 4B have various features, which will be described in detail later. Some of these features allow the widths of the first and second injection units 4A and 4B to be kept small. In this embodiment, the first and second injection units 4A and 4B are arranged in parallel and symmetrically positioned with respect to the mechanical center line C of the mold clamping unit 2. Since the widths of each unit are kept small, the width W of the twin injection molding machine 1 is also kept small, and an increase in the installation area is suppressed.

[0012] The twin injection molding machine 1 according to the present embodiment is a so-called metal injection molding machine that melts and injects metal. However, various features of the first and second injection units 4A and 4B described later are not limited to injection units that inject metal. In other words, they can be implemented in the same way in a twin injection molding machine equipped with two injection units that inject resin.

[0013] <Mold clamping device> The mold clamping device 2 includes a fixed platen 6 fixed to a bed 5, a movable platen 7 slidably provided on the bed 5, and a mold clamping housing 8 slidably provided on the bed 5. The fixed platen 6 and the mold clamping housing 8 are connected by a plurality of tie bars 10, 10, ..., and the movable platen 7 is slidably disposed between the fixed platen 6 and the mold clamping housing 8. A toggle mechanism 12 is provided between the mold clamping housing 8 and the movable platen 7. When a drive system component (not shown), for example a mold clamping motor, is driven to bend and extend the toggle mechanism 12, the movable platen 7 slides to open and close the mold.

[0014] <Injection unit bed> In this embodiment, the first and second injection units 4A and 4B are mounted on beds 22A and 22B, respectively, as shown in Fig. 2. The beds 22A and 22B are separable from each other. The twin injection molding machine 1 shown in Fig. 1 comprises a mold clamping unit 2 mounted on a bed 5, a first injection unit 4A mounted on a bed 22A, and a second injection unit 4B mounted on a bed 22B, which can be separated and transported separately from a factory to a customer.

[0015] <Injection device> FIG. 3 shows an enlarged view of a part of the twin injection molding machine 1 according to the present embodiment. As described above, the first and second injection units 4A and 4B according to the present embodiment are arranged symmetrically with respect to the machine center line C of the mold clamping unit 2. The components constituting the first and second injection units 4A and 4B are also substantially symmetrical with respect to the machine center line C. Therefore, the first injection unit 4A, which is one of the injection units, will be described, and the description of the second injection unit 4B will be omitted unless necessary. Note that each component of the first injection unit 4A is given a reference number combining a number and the letter "A," and the equivalent components of the second injection unit 4B are given a reference number combining the same number and the letter "B."

[0016] The first injection unit 4A includes a heating cylinder 14A, a screw (not shown) that is housed in the heating cylinder 14A, and a screw drive unit 15A that drives the screw. The rear end of the screw is normally connected to the screw drive unit 15A and driven by the screw drive unit 15A. In this case, the rear end of the screw should be shown in FIG. 3. However, FIG. 3 shows the screw in a state in which it is separated from the screw drive unit 15A and completely housed in the heating cylinder 14A. In other words, the heating cylinder 14A and the screw can be removed from the first injection unit 4A by a hoist crane for the purpose of maintenance or the like.

[0017] The first injection unit 4A includes a support structure 18A and a movement mechanism 20A. The support structure 18A is a structure that supports the heating cylinder 14A, and will be described in detail below. The movement mechanism 20A is made up of piston cylinder units 21A, 21A, and is configured to move the first injection unit 4A closer to or farther away from the mold clamping unit 2. These piston cylinder units 21A, 21A are characterized by the attachment points where their respective ends are attached, and will be described later.

[0018] <Support structure> In this embodiment, the support structure 18A includes a support plate including a flange plate 24A and a rear plate 25A. The support plates, i.e., the flange plate 24A and the rear plate 25A, are connected by a plurality of rods 26A, 26A, .... The heating cylinder 14A has a flange portion 28A formed in its center, and the flange plate 24A supports the heating cylinder 14A in a fixed manner at the flange portion 28A. FIG. 4 shows the flange plate 24A, which has a cylinder storage portion 30A formed of a substantially U-shaped groove in the center. The flange portion 28A of the heating cylinder 14A (see FIG. 3) is fixed to the flange portion 28A via a joint plate (not shown).

[0019] As shown in FIG. 4, the flange plate 24A has rods 26A, 26A, ... attached to the top and bottom of both left and right ends. The flange plate 24A has cutouts 31A, 31A formed between the two upper and lower rods 26A, 26A at both left and right ends. The piston cylinder units 21A, 21A pass through these cutouts 31A, 31A. That is, the left and right piston cylinder units 21A, 21A are respectively disposed between the two upper and lower rods 26A, 26A, .... As a result of this arrangement, the width of the first injection device 4A (see FIG. 3) is reduced. Note that the rear plate 25A, which is the other support plate, also has cutouts formed in a similar manner through which the piston cylinder units 21A, 21A pass.

[0020] <Screw drive unit> As shown in Fig. 3, the screw drive unit 15A is provided on a drive unit frame 33A. The drive unit frame 33A is composed of two plates and connecting rods 35A, 35A connecting these plates. One of the two plates is the rear plate 25A of the support structure 18A. In other words, the rear plate 25A is a part of the support structure 18A and also serves as a plate constituting the drive unit frame 33A. The other plate 34A constituting the drive unit frame 33A is shown by dotted lines in Fig. 3. The screw drive unit 15A according to this embodiment is provided on such a drive unit frame 33A.

[0021] The screw drive device 15A includes a drive source for rotating the screw, i.e., drive system components, and drive system components for driving the screw in the axial direction. In the screw drive device 15A according to this embodiment, all of these drive system components are disposed on the side of the screw drive device 15A that is away from the machine center line C.

[0022] For example, the drive system components for rotating the screw include a screw rotation servomotor 36A. The screw rotation servomotor 36A is provided on the side of the screw drive device 15A that is spaced apart from the machine center line C. The drive system components for driving the screw in the axial direction include a group of hydraulic accumulators, namely, injection accumulators 38A, 38A, an oil recovery accumulator 39A, and a pilot valve accumulator 40A. All of these are provided on the side of the screw drive device 15A that is spaced apart from the machine center line C. The pilot valve accumulator 40A is for driving a pilot valve that controls the valve flow rate to control the injection speed.

[0023] As described above, the second injection unit 4B is configured similarly to the first injection unit 4A, and each part is arranged substantially symmetrically with respect to the machine center line C. That is, in the first and second injection units 4A and 4B, the drive system parts are all arranged on the side of the screw drive units 15A and 15B that is farther from the machine center line C. In this way, the drive system parts of the first and second injection units 4A and 4B do not interfere with each other. Therefore, the first and second injection units 4A and 4B can be arranged as close as possible. This allows the width W of the twin injection molding machine 1 (see FIG. 1) according to this embodiment to be reduced. Furthermore, since the drive system parts are all arranged on both ends of the twin injection molding machine 1, it also has the effect of facilitating maintenance.

[0024] <Installation position of piston cylinder unit> One end of each of the piston cylinder units 21A, 21A constituting the moving mechanism 20A is fixed to the fixed platen 6 as shown in FIG. 3. In contrast, the other end of each of the piston cylinder units 21A, 21A is fixed to a fixed member further rearward than the rear end of the heating cylinder 14A, not in the vicinity of the rear end of the heating cylinder 14A. Specifically, the piston cylinder units 21A, 21A are fixed to clevises 42A, 42A as fixed members formed in a predetermined portion of the driving device frame 33A. These clevises 42A, 42A are provided on the plate 34A constituting the driving device frame 33A. The fixed member is not limited to the clevises 42A, 42A, and may be any member capable of fixing the piston cylinder units 21A, 21A.

[0025] As a result of the piston cylinder units 21A, 21A being attached in this manner, the piston cylinder units 21A, 21A are long and a large stroke is ensured. Therefore, the first injection unit 4A according to this embodiment can sufficiently separate the heating cylinder 14A from the fixed platen 6 as shown in FIG. 3. Therefore, the heating cylinder 14A and the screw can be easily removed by a hoist crane or the like. In other words, there is no need to rotate the first injection unit 4A to perform maintenance on the screw or the like.

[0026] <Conventional injection molding machine> The twin injection molding machine 1 according to the present disclosure will be compared with a conventional injection molding machine. FIG. 5 shows a conventional injection molding machine 100. This injection molding machine 100 is a metal injection molding machine, and is composed of a clamping device 101 and an injection device 102. This conventional injection molding machine 100 has only one injection device 102, which is different in number from the twin injection molding machine 1 according to the present embodiment (see FIG. 1). However, since the conventional twin injection molding machine is also simply equipped with two injection devices 102 that the conventional injection molding machine 100 has, the excellent effects of the twin injection molding machine according to the present embodiment will be easily understood by explaining the structure of this conventional injection molding machine 100.

[0027] The mold clamping device of a conventional injection molding machine 100 includes a fixed platen 105, a movable platen 106, and a mold clamping housing 107. The fixed platen 105 and the mold clamping housing 107 are connected by a plurality of tie bars 109, 109, ..., and the movable platen 106 is provided so as to be able to slide between the fixed platen 105 and the mold clamping housing 107. A toggle mechanism 110 is provided between the mold clamping housing 107 and the movable platen 106, and the mold is opened and closed by bending and extending the toggle mechanism 110.

[0028] The injection unit 102 of the conventional injection molding machine 100 includes a heating cylinder 114, a screw (not shown) that is placed in the heating cylinder 114, and a screw drive unit 115 that drives the screw. It also includes a support structure 125 that supports the heating cylinder 114, and piston-cylinder units 116, 116 that are moving mechanisms that drive the injection unit 102 in directions toward and away from the fixed platen 105.

[0029] <Drive system parts> The screw drive unit 115 is provided with a plurality of drive system components. First, a servo motor 117 that rotates and drives the screw is provided. Next, a group of hydraulic accumulators that are driven in the axial direction, namely, the injection accumulators 118, 118, the oil recovery accumulator 120, and the pilot valve accumulator 121, are provided. In the screw drive unit 115, these drive system components are arranged as follows. First, the servo motor 117 and the oil recovery accumulator 120 are provided on one side, and the injection accumulators 118, 118, and the pilot valve accumulator 121 are provided on the other side. Therefore, if two such injection units 102 are arranged in parallel, the drive system components will interfere with each other and they cannot be arranged close enough to each other. In other words, the width W2 of the injection molding machine 100 will be large.

[0030] <Support structure> A support structure 125 supporting a heating cylinder 114 of a conventional injection molding machine 100 is composed of a flange plate 126, a rear plate 127, and a number of rods 129, 129, ... that connect these together. The heating cylinder 114 is fixed at its rear end to the rear plate 127, and is fixed to the flange plate 126 at a flange portion 130 formed in the center.

[0031] FIG. 6 shows a conventional flange plate 126. The flange plate 126 is substantially rectangular, and a cylinder storage section 131 consisting of a substantially U-shaped groove is formed in the center. A flange section 130 of the heating cylinder 114 (see FIG. 5) is fixed to the flange plate 126 via a joint plate (not shown). Rods 129, 129, ... are attached to the upper and lower left and right ends of the flange plate 126. Since the conventional flange plate 126 does not have notches formed at the left and right ends, the piston cylinder units 116, 116 are arranged outside the flange plate 126. Since the interval between the two piston cylinder units 116, 116 is wide, the width W2 of the injection unit 102 of the conventional injection molding machine 100 (see FIG. 5) is large. If two injection units 102 are arranged side by side, the width W2 becomes large.

[0032] <Conventional movement mechanism> As shown in Fig. 5, one end of the piston cylinder unit 116, which is a conventional moving mechanism, is provided on the fixed platen 105, and the other end is provided on the rear plate 127 of the support structure 125. In other words, it is provided near the rear end of the heating cylinder 114. In other words, the length of the piston cylinder unit 116 is relatively short, and the stroke of movement is short. Therefore, when performing maintenance on the heating cylinder 114, etc., it is necessary to rotate the injection unit 102 as shown by the dotted line in Fig. 5. This is different from the twin injection molding machine 1 (see Fig. 1) according to this embodiment.

[0033] <Twin injection molding machine according to the second embodiment> The twin injection molding machine 1 (see FIG. 1) according to this embodiment can be modified in various ways. For example, it can be modified so that the injection materials injected from the first and second injection units 4A and 4B are merged and injected. FIG. 7 shows a twin injection molding machine 1' according to a second embodiment, which is equipped with a merge adapter 50 and a common injection nozzle 51. The explanation of the parts that have the same functions as those explained in the twin injection molding machine 1 (see FIG. 1) according to the previous embodiment will be omitted and the same numbers will be used.

[0034] <Merge adapter> 7, the merging adapter 50 has two flow path inlets 53A, 53B and one flow path outlet 54. The heating cylinders 14A, 14B of the first and second injection devices 4A, 4B are connected to the two flow path inlets 53A, 53B, respectively, and a common injection nozzle 51 is provided at the flow path outlet 54. Therefore, when the injection material is injected in the first and second injection devices 4A, 4B, the injection material is merged and injected from the common injection nozzle 51.

[0035] <Twin injection molding machine according to the third embodiment> FIG. 8 shows a part of a twin injection molding machine 1'' according to a third embodiment. Specifically, a front view of the first and second injection units 4A', 4B' is shown. In this embodiment, the flange plates 24A', 24B' have different heights. As a result, the heights of the heating cylinders 14A, 14B in the first and second injection units 4A', 4B' are different. However, they are arranged substantially symmetrically with respect to the machine center line C. Even if the first and second injection units 4A', 4B' are arranged with a difference in height, the width W' of the twin injection molding machine 1'' can be reduced.

[0036] <Other Modifications> In the twin injection molding machine 1 (see FIG. 1) according to this embodiment, the first and second injection units 4A and 4B are arranged in parallel. This can be modified. Specifically, the first and second injection units 4A and 4B are shifted from each other in angle so that the tips of the heating cylinders 14A and 14B are close to each other, and the screw drive units 15A and 15B are slightly spaced apart. Other modifications are also possible. In the twin injection molding machine 1 according to this embodiment, the mold clamping mechanism of the mold clamping device 2 is composed of a toggle mechanism 12, but a direct pressure type mold clamping mechanism can be adopted.

[0037] Although the invention made by the present inventor has been specifically described above based on the embodiment, it goes without saying that the present invention is not limited to the embodiment already described, and various modifications are possible without departing from the gist of the invention. The above-described examples may be implemented in appropriate combination. [Explanation of symbols]

[0038] 1 Twin injection molding machine 2 Clamping unit 4A First injection unit 4B Second injection unit C Machine centerline 5 Bed 6 Fixed plate 7 Movable plate 8 Clamping housing 10 Tie bar 12 Toggle mechanism 14A Heating cylinder 15A Screw drive unit 18A Support structure 20A Movement mechanism 21A Piston cylinder unit 22A Bed 24A Flange Plate 25A Rear plate 26A Rod 28A Flange section 30A Cylinder storage section 31A Cutout 33A Drive unit frame 35A Connecting rod 36A Servomotor for screw rotation 38A Injection accumulator 39A Oil recovery accumulator 40A Pilot valve accumulator 42A Clevis 50 Merge Adapter 51 Common injection nozzle

Claims

1. a mold clamping device that clamps the mold; an injection device including a heating cylinder, a screw housed in the heating cylinder, and a screw drive device for driving the screw; the injection unit is provided with a piston cylinder unit which is a moving mechanism for moving the injection unit in a direction approaching or separating from the mold clamping unit, The injection device includes a support structure for supporting the heating cylinder, the support structure including a support plate for supporting the heating cylinder; An injection molding machine, wherein the support plate has a notch through which the piston cylinder unit passes.

2. 2. The injection molding machine according to claim 1, wherein one end of the piston-cylinder unit is fixed to a fixing member located further rearward than a rear end of the heating cylinder of the injection device.

3. 3. The injection molding machine according to claim 2, wherein the fixed member is a frame of the screw drive device of the injection unit.

4. 4. The injection molding machine according to claim 1, wherein the support plate is composed of a rear plate that supports the heating cylinder at a rear end and a flange plate that supports the heating cylinder at a central portion, and the support structure includes a plurality of rods that connect the rear plate and the flange plate.

5. 5. The injection molding machine according to claim 1, wherein the injection material of the injection unit is a metal.

Images