Lifting device and injection molding machine

Abstract

To relax restrictions on a shape and dimensions of an injection molding machine base.SOLUTION: In one embodiment, a lifting device 40 includes a lifting plate 41 on which an injection device 30 is mounted, and a drive part 42 that moves the lifting plate 41 up and down relative to a base 10. The drive part 42 includes a feed screw 45 that is made up of a screw shaft 45a fixed to the base 10 and a nut 45b that supports the lifting plate 41 and moves up and down integrally with the lifting plate 41 while rotating.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a lifting device and an injection molding machine. [Background technology]

[0002] An injection molding machine is known that is configured with a mold clamping device to which a mold is attached and an injection device that supplies molding material to the mold attached to the mold clamping device. Another known example of an injection molding machine is an injection molding machine that combines a vertical mold clamping device and a horizontal injection device.

[0003] Patent Document 1 describes a lifting mechanism that moves a horizontal injection unit combined with a vertical mold clamping unit up and down relative to a base. The lifting mechanism described in Patent Document 1 is composed of a servo motor, a ball screw, a ball nut, etc. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-280059 Summary of the Invention [Problem to be solved by the invention]

[0005] The mechanism or device for moving the injection unit up and down relative to the base can be one factor that limits the shape and size of the base. [Means for solving the problem]

[0006] According to the present disclosure, a lifting device according to one embodiment includes a drive unit that moves a lifting plate, on which an injection device is mounted, up and down relative to a base. The drive unit includes a feed screw that is made up of a screw shaft fixed to the base and a nut that supports the lifting plate and moves up and down integrally with the lifting plate while rotating. [Effects of the Invention]

[0007] According to the present disclosure, restrictions on the shape and dimensions of the base of the injection molding machine can be relaxed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view schematically showing an operation side of an injection molding machine according to an embodiment. FIG. [Figure 2] 2 is a side view showing a state in which the lift plate shown in FIG. 1 is lowered to a lower limit position and a state in which the lift plate is raised to an upper limit position, in comparison. FIG. [Figure 3] 2 is a front view showing a state in which the lifting plate shown in FIG. 1 is lowered to a lower limit position and a state in which the lifting plate is raised to an upper limit position, in comparison. FIG. [Figure 4] 1 is a plan view showing a structure of a lifting device according to an embodiment; [Figure 5] FIG. 2 is a bottom view showing the structure of the lifting device according to the embodiment. [Figure 6] 1 is a side view showing a structure of an elevator device according to an embodiment. [Figure 7] FIG. 5 is an enlarged cross-sectional view taken along line AA in FIG. [Figure 8A] FIG. 10 is a side view schematically showing a lifting device as a comparative example. [Figure 8B] FIG. 10 is a front view schematically showing a lifting device as a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. In all drawings used to describe the embodiments, the same reference numerals are used for identical or substantially identical configurations and elements. Furthermore, as a general rule, configurations and elements that have already been described will not be described again.

[0010] <Injection molding machine overview> 1 is a side view schematically showing the operation side of an injection molding machine 1A according to this embodiment. The injection molding machine 1A has a base 10, a mold clamping device 20, an injection device 30, an elevating device 40, and a moving device 50.

[0011] The base 10 is a base on which the clamping unit 20, the injection unit 30, and other components of the injection molding machine 1A are mounted, and is generally called a "bed." Therefore, in the following description, the base 10 may be called the "bed 10."

[0012] A control panel 11 for controlling the injection device 30 and the like is provided inside the bed 10. From another perspective, a controller for controlling the injection device 30 and the like is provided inside the bed 10.

[0013] At least a portion of the bed 10 on which the injection unit 30, the lifting unit 40, and the moving unit 50 are mounted is composed of a plurality of frames 12 and a top plate portion 13 supported by these frames 12, and is lower than another portion of the bed 10 on which the mold clamping unit 20 is mounted. The top plate portion 13 has a substantially rectangular planar shape and has an area large enough to accommodate the lifting unit 40.

[0014] The top plate 13 is supported from below by a plurality of frames 12 arranged around its periphery. In other words, the frames 12 are pillars that support the top plate 13. The control panel 11 is located inside the plurality of frames 12 and in a space 14 below the top plate 13.

[0015] The mold clamping unit 20, injection unit 30, lifting unit 40, and moving unit 50 perform various operations under the overall control of the control panel 11. For example, the mold clamping unit 20 performs mold opening / closing and mold clamping, etc., based on the control of the control panel 11. Also, the injection unit 30 performs metering and injection of molding material, etc., based on the control of the control panel 11.

[0016] <Mold clamping device> The mold clamping unit 20 includes a turntable 21 and an upper movable platen 22 that face each other in the vertical direction. Although not shown in the figure, a fixed platen is provided below the turntable 21, and a lower movable platen is provided below the fixed platen.

[0017] The upper movable platen 22 and the lower movable platen are connected to each other by tie bars 23 that pass through the turntable 21 and the fixed platen. Furthermore, a mold clamping mechanism is provided between the fixed platen and the lower movable platen.

[0018] A plurality of molds are attached to the mold clamping unit 20. In this embodiment, two lower molds b1 and b2 are attached to the upper surface of the turntable 21, and one upper mold a is attached to the lower surface of the upper movable platen 22. The two lower molds b1 and b2 are attached at positions that are 180 degrees apart in the rotation direction of the turntable 21.

[0019] The turntable 21 can rotate ±180 degrees, so that the lower mold b1 or the lower mold b2 can be selectively opposed to the upper mold a by rotating the turntable 21.

[0020] From another perspective, the upper mold a and the opposing lower mold can be interchanged by rotating the turntable 21 by 180 degrees. In other words, the combination of the upper and lower molds can be changed by rotating the turntable 21 by 180 degrees.

[0021] The upper movable platen 22 is driven up and down by a mold opening and closing mechanism. At this time, the tie bars 23 guide the up and down movement (lifting and lowering) of the upper movable platen 22. When the upper movable platen 22 descends, the upper mold a attached to the upper movable platen 22 is brought into abutment with the lower mold b1 or b2 attached to the turntable 21. In other words, the upper and lower molds are closed.

[0022] On the other hand, when the upper movable platen 22 rises, the upper mold a attached to the upper movable platen 22 moves away from the lower mold b1 or the lower mold b2 attached to the turntable 21. In other words, the upper and lower molds are opened.

[0023] As described above, the mold clamping unit 20 according to this embodiment opens and closes the mold in the up-down direction (vertical direction). In other words, the mold clamping unit 20 according to this embodiment is a vertical mold clamping unit suitable for multi-material molding and insert molding.

[0024] Therefore, the injection molding machine 1A of the present embodiment equipped with the mold clamping device 20 is suitable for multi-material molding and insert molding. However, molding performed using the injection molding machine 1A is not limited to multi-material molding and insert molding.

[0025] <Injection device> The injection unit 30 supplies molding material to a mold attached to the mold clamping unit 20. More specifically, the injection unit 30 is equipped with a heating cylinder 31 to which raw molding material is supplied. The heating cylinder 31 is arranged horizontally, and its axis intersects (is perpendicular to) the mold opening and closing direction of the mold clamping unit 20.

[0026] Here, the axial direction (longitudinal direction) of the heating cylinder 31 is defined as the "front-rear direction." Furthermore, the side where the mold clamping device 20 is arranged is defined as the "front (front side)," and the opposite side is defined as the "rear (rear side)." However, these definitions are merely for the convenience of explanation.

[0027] The heating cylinder 31 heats and melts the supplied raw material. In this embodiment, resin pellets are supplied to the heating cylinder 31 and melted. A screw is provided inside the heating cylinder 31. The melted resin pellets (molten resin) are kneaded by the rotating screw.

[0028] The kneaded molten resin is extruded by the screw from the heating cylinder 31. More specifically, the molten resin is pushed by the advancing screw and injected from a nozzle 32 provided at the tip of the heating cylinder 31.

[0029] As described above, the injection unit 30 according to this embodiment is equipped with the heating cylinder 31 arranged horizontally, and supplies molding material from the side to the mold attached to the mold clamping unit 20. In other words, the injection unit 30 according to this embodiment is a horizontal injection unit that is suitable for installation in a place with a low ceiling.

[0030] As described above, the mold clamping unit 20 according to this embodiment is a vertical mold clamping unit. In other words, the injection molding machine 1A according to this embodiment is an injection molding machine that combines a vertical mold clamping unit and a horizontal injection unit. In other words, the injection molding machine 1A is a "vertical mold clamping / horizontal injection molding machine." Therefore, the injection molding machine 1A has the advantages of both a vertical mold clamping unit and a horizontal injection unit.

[0031] <Lifting device> The lifting device 40 includes a lifting plate 41 and a drive unit 42. The lifting plate 41 is moved up and down relative to the bed 10 by the drive unit 42. When the lifting plate 41 moves up and down relative to the bed 10, the injection device 30 mounted on the lifting plate 41 also moves up and down relative to the bed 10.

[0032] From another perspective, the height of the injection device 30 can be adjusted by the lifting device 40. For example, by adjusting the height of the injection device 30 by the lifting device 40, the position (height) of the nozzle 32 and the position (height) of the sprue bushing of the mold can be aligned.

[0033] Fig. 2 is a side view showing a state in which the lift plate 41 is lowered to the lowest position and a state in which the lift plate 41 is raised to the highest position, and Fig. 3 is a front view showing a state in which the lift plate 41 is lowered to the lowest position and a state in which the lift plate 41 is raised to the highest position.

[0034] The lifting plate 41 on which the injection unit 30 is mounted moves up and down between a lower limit position shown on the left side in FIGS. 2 and 3 and an upper limit position shown on the right side in FIGS. 2 and 3. The height difference D between the lower limit position and the upper limit position shown in the figures is 65 mm. In other words, the lifting stroke of the lifting plate 41 is 65 mm. From another perspective, the lifting unit 40 can lift and lower the injection unit 30 by 65 mm.

[0035] <Lifting plate> Fig. 4 is a plan view showing the structure of the lifting device 40, Fig. 5 is a bottom view, and Fig. 6 is a side view. Fig. 7 is an enlarged cross-sectional view taken along line AA in Fig. 4.

[0036] The lifting plate 41 is disposed on the bed 10. Although not shown in Figs. 4 to 6, as already described, the injection device 30 is mounted on the lifting plate 41. More specifically, the moving device 50 is mounted on the lifting plate 41, and the injection device 30 is mounted on the moving device 50 (see Fig. 1).

[0037] The lifting device 40 moves the lifting plate 41, on which the moving device 50 and the injection device 30 are mounted, up and down relative to the bed 10. From another perspective, the lifting plate 41 is a movable stage that moves up and down while mounting the moving device 50 and the injection device 30.

[0038] <Drive unit> The drive unit 42 that moves the lift plate 41 up and down includes a drive source 43, a power transmission mechanism 44, and a feed screw 45. The drive source 43 is a geared motor, and is provided on the lift plate 41. More specifically, the drive source 43 is disposed on the operation side of the lift plate 41 at the center or approximately the center in the longitudinal direction.

[0039] The drive unit 42 includes a plurality of feed screws 45. More specifically, the drive unit 42 includes four feed screws 45, each including a screw shaft 45a and a nut 45b. Two of the feed screws 45 are disposed on the operation side of the lift plate 41, and the other two are disposed on the non-operation side of the lift plate 41.

[0040] The screw shaft 45a of each feed screw 45 is immovably provided on the bed 10. More specifically, one end (lower end) of the screw shaft 45a of each feed screw 45 is fixed to the top plate portion 13 of the bed 10. From another perspective, the screw shaft 45a of each feed screw 45 extends vertically upward from the top plate portion 13 of the bed 10.

[0041] The nuts 45b of the respective feed screws 45 are threadedly coupled to the respective screw shafts 45a. The portions of the screw shafts 45a protruding from the nuts 45b are inserted into the lifting plate 41. As a result, the lifting plate 41 is supported from below by the nuts 45b of the respective feed screws 45.

[0042] 7, an annular cover member 60 is fitted inside a through-hole formed in the lift plate 41. A portion of the screw shaft 45a protruding from the nut 45b penetrates the cover member 60 and protrudes from the lift plate 41. As a result, the upper surface of the nut 45b of each feed screw 45 contacts the lower surface of the cover member 60.

[0043] From another perspective, each nut 45b supports the lift plate 41 via the cover member 60. In other words, the lift plate 41 is placed on the four nuts 45b. Therefore, when the nuts 45b are rotated and moved in the axial direction of the screw shaft 45a, the lift plate 41 moves up and down relative to the bed 10.

[0044] The cover member 60 may be omitted, and the upper surface of the nut 45b may be brought into direct contact with the periphery of the through-hole provided in the lifting plate 41.

[0045] As shown primarily in Figure 5, the power transmission mechanism 44 includes a drive sprocket 44a, a driven sprocket 44b, and a roller chain 44c. The drive sprocket 44a is fixed to the output shaft of the drive source 43 and is driven to rotate by the drive source 43. The driven sprocket 44b is fixed by a bolt to the underside of the nut 45b of each feed screw 45. From another perspective, the nut 45b and the driven sprocket 44b are integrated.

[0046] The roller chain 44c is wound around the drive sprocket 44a and the four driven sprockets 44b. As a result, the driving force output from the drive source 43 is transmitted to the nuts 45b of the respective feed screws 45 via the power transmission mechanism 44, causing the nuts 45b to rotate.

[0047] Idler sprockets (tension sprockets) 44d are located on both sides of the drive sprocket 44a to apply appropriate tension to the roller chain 44c. The nut 45b and driven sprocket 44b can be separated by releasing the bolts. Furthermore, by removing the cover member 60 shown in FIG. 7 from the lifting plate 41, the nut 45b from which the driven sprocket 44b has been separated can be removed above the lifting plate 41.

[0048] <Movement Device> 1 again, the moving device 50 can move the injection device 30 forward and backward on the lifting plate 41. More specifically, the moving device 50 can move the injection device 30 in a direction approaching the mold clamping device 20 (forward) and in a direction away from the mold clamping device 20 (rearward).

[0049] The moving device 50 includes a pair of cylinders. The moving device 50 extends the rods of the respective cylinders to move the injection device 30 backward, and retracts the rods of the respective cylinders to move the injection device 30 forward.

[0050] However, the relationship between the extension and contraction of the rod and the movement direction of the injection unit 30 may be the opposite of the above relationship. That is, in another embodiment, when the rod of the cylinder extends, the injection unit 30 moves forward, and when the rod of the cylinder retracts, the injection unit 30 moves backward. The cylinder may be a hydraulic cylinder or an air cylinder. Also, the cylinder may be replaced with another actuator.

[0051] <Summary> As described above, in this embodiment, the nut 45b of the feed screw 45, the drive source 43, and the power transmission mechanism 44 move up and down integrally with the lifting plate 41. On the other hand, the screw shaft 45a of the feed screw 45 is fixed to the bed 10 and does not move or rotate. From another perspective, the screw shaft 45a does not protrude into the space 14 below the top plate portion 13. Therefore, there is no risk of the screw shaft 45a coming into contact with the control panel 11 in the space 14.

[0052] As a result, according to this embodiment, when designing the shape and dimensions of the bed 10, there is no need to consider interference between the screw shaft 45a and the control panel 11, improving the degree of freedom in designing the bed 10. Specifically, the height and width of the bed 10 can be reduced, thereby making the bed 10 more compact and lower.

[0053] <Comparative Example> Fig. 8A is a side view schematically showing a comparative example of lifting device 140. Fig. 8B is a front view schematically showing a comparative example of lifting device 140. Like lifting device 40 according to the present embodiment, lifting device 140 moves lifting plate 141 up and down relative to bed 10 using feed screw 145.

[0054] However, in the lifting device 140, the upper end of the screw shaft 145a is fixed to the lifting plate 141, and the nut 145b is rotatably provided on the bed 10. When the nut 145b is rotated by the drive source 143, which is also provided on the bed 10, the screw shaft 145a moves up and down, and accordingly the lifting plate 141 moves up and down.

[0055] In the lifting device 140, the screw shaft 145a penetrates the top plate 13 of the bed 10 and protrudes into the space 14 below the top plate 13. Therefore, there is a risk that the screw shaft 145a may come into contact with the control panel 11 in the space 14. Therefore, when using the lifting device 140, it is necessary to design the shape and dimensions of the bed 10 so that the screw shaft 145a does not come into contact with the control panel 11. As a result, the height and width of the bed 10 may increase, or the shape of the bed 10 may be restricted.

[0056] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. For example, the mold clamping unit 20 is not limited to a vertical mold clamping unit, and the injection unit 30 is not limited to a horizontal injection unit. The sprockets 44a and 44b constituting the power transmission mechanism 44 of the lifting unit 40 can be replaced with pulleys, and the roller chain 44c can be replaced with a belt. [Explanation of symbols]

[0057] 1A: Injection molding machine 10: Base (bed) 11: Control panel 12: Frame 13: Top plate 14: Space 20: Mold clamping device 21: Turntable 22: Upper movable board 23: Taiba 30: Injection device 31: Heating cylinder 32: Nozzle 40,140: Lifting device 41,141: Lifting plate 42: Drive unit 43,143:Drive source 44: Power transmission mechanism 44a: Drive sprocket 44b: driven sprocket 44c: Roller chain 44d: Idler sprocket (tension sprocket) 45a, 145a: screw shaft 45b, 145b: Nut 50: Mobile device 60: Lid member

Claims

1. Lifting equipment, including: a lifting plate disposed on the base of the injection molding machine and on which the injection unit is mounted; and a drive unit including a feed screw for moving the lifting plate up and down relative to the base; where: a screw shaft constituting the feed screw is fixed to the base; A nut constituting the feed screw supports the lift plate and moves up and down integrally with the lift plate while rotating.

2. The lifting device according to claim 1, the drive unit includes a drive source and a power transmission mechanism that transmits a drive force output from the drive source to the nut, The drive source and the power transmission mechanism are provided on the lifting plate and move up and down integrally with the lifting plate.

3. The lifting device according to claim 2, the drive unit includes a plurality of the feed screws, A lifting device, wherein the driving force output from the driving source is transmitted to the nuts of the respective feed screws via the power transmission mechanism.

4. The lifting device according to claim 3, The power transmission mechanism includes: a drive sprocket that is rotationally driven by the drive source; a driven sprocket provided on each of the nuts; a roller chain wound around the drive sprocket and the driven sprocket.

5. Injection molding machines, including: a clamping device to which the mold is attached; an injection unit that supplies molding material to a mold attached to the mold clamping unit; and an elevating device capable of moving the injection device in the up and down direction; where: the lifting device is disposed on a base and includes a lifting plate on which the injection device is mounted, and a drive unit that includes a feed screw and moves the lifting plate up and down relative to the base, a screw shaft constituting the feed screw is fixed to the base; A nut constituting the feed screw supports the lift plate and moves up and down integrally with the lift plate while rotating.

6. 6. The injection molding machine according to claim 5, The apparatus further includes a moving device interposed between the lifting device and the injection device, The moving device is capable of moving the injection device on the lifting plate in a direction toward the mold clamping device and a direction away from the mold clamping device.

7. 6. The injection molding machine according to claim 5, The injection molding machine, wherein the mold clamping device is a vertical mold clamping device and the injection device is a horizontal injection device.

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