Machine base for injection molding machine

Abstract

A machine base (10) for an injection molding machine (12) comprising: an upper frame (14) which supports the injection molding machine (12) from below, and two lower frames (16, 18) which support the upper frame (14) from below, being in contact with the upper frame (14), the two lower frames (16, 18) having a fixed space, wherein the injection molding machine (12) comprises a mold clamping device (22) configured to open and close a mold (20) and an injection device configured to inject molten resin into the mold (20), wherein the upper frame (14) supports at least the mold clamping device (22) from below, characterized in that the upper frame (14) and the two lower frames (16, 18) comprise a plurality of first elements (14a, 14b, 16a, 16b, 18a, 18b) extending along an opening / closing direction (A) of the mold (20), and a plurality of second elements (14c, 14d, 16c, 16d, 18c, 18d) extending in a direction (B) crossing the opening / closing direction (A) of the mold (20) and connecting the plurality of first elements (14a, 14b, 16a, 16b, 18a, 18b), and that the two lower frames (16, 18) each support the upper frame (14) from below such that the plurality of first elements (16a, 16b, 18a, 18b) of the lower frame (16, 18) are in contact with the first elements (14a, 14b) of the upper frame (14).

Description

Background of the inventionField of the invention

[0001] The present invention relates to a machine base (base frame) for supporting an injection molding machine from below. Description of the state of the art

[0002] Japanese Patent Laid-Open No. JP 2010-12720 A describes a machine base having an upper frame supporting an injection molding machine from below, a plurality of support pillars extending downward from a bottom surface of the upper frame, and a lower frame supporting the plurality of support pillars below the upper frame.

[0003] DE 101 52 394 A1 discloses a rotating device for horizontal injection molding machines. This can be converted into a standard injection molding machine. The machine base then comprises a frame supported partly by pillars and partly by a block-like support element, with an empty area provided below the molds of the injection molding machine.

[0004] DE 10 2010 014 452 A1 shows a machine base for an injection molding machine, which consists of a base frame which has a vertically aligned support element in each of its end regions, which in turn are designed to receive a carrier frame.

[0005] Various methods for aligning an injection molding machine on a machine base are also known. For example, Japanese Patent Application Laid-Open No. JP 2006-199 004 A discloses a mold clamping device for an injection molding machine, in which a plate-shaped machine base supports a guide frame with two guide rails at different heights. Another alignment option is described in DE 32 12 670 A1. There, the components of the injection molding machine are supported by a single frame. The machine can be aligned using mutually movable wedges under the feet of the machine base. Summary of the invention

[0006] However, with such a machine base, the number of components increases, leading to an increase in manufacturing labor. Therefore, there is a concern that production costs will be high. Furthermore, there is a further concern that the load acting on the injection molding machine will cause deflection in sections of the upper frame not supported by the multiple support pillars. Supporting the upper frame by the multiple support pillars also causes the center of gravity of the machine base to be high, which leads to the further problem of increasing the likelihood of vibration generation.

[0007] Accordingly, it is an object of the present invention to provide a machine base for an injection molding machine which has high rigidity, can suppress vibrations and can be manufactured at low cost.

[0008] This object is achieved by the machine base according to claim 1. Advantageous embodiments of the invention emerge from the subclaims.

[0009] According to the present invention, since support pillars are not used, the number of components is reduced. This makes it possible to reduce the man-hours, such as assembly man-hours and welding man-hours, in manufacturing the machine base. In addition, since the contact area between the upper frame and the lower frame becomes large compared to the case where the upper frame is supported by the support pillars, deflection of the upper frame due to the load of the injection molding machine is avoided. Therefore, it is possible to ensure the rigidity of the machine base. Furthermore, since no support pillar is used, it is possible to lower the center of gravity of the machine base and prevent the generation of vibrations. This makes it possible to manufacture the machine base with high rigidity and in which vibrations can be avoided at a low cost.

[0010] The above and other objects, features and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of example. Short description of the drawings Fig. 1 is a side view of a machine base in an embodiment according to the present invention, Fig. 2 is a plan view of a Fig. 1 shown upper frame, and Fig. 3 is a plan view of Fig. 1 lower frames shown. Description of the preferred embodiments

[0011] Hereinafter, a machine frame for an injection molding machine according to the present invention will be described in detail based on a preferred embodiment with reference to the accompanying drawings. [Structure of the present embodiment]

[0012] As in Fig. 1, a machine base 10 for an injection molding machine according to the present embodiment (hereinafter also referred to as a machine base 10 of the present embodiment) includes an upper frame 14 that supports the injection molding machine 12 from below, and two lower frames 16, 18 that support the upper frame 14 from below in a state of being in contact with a bottom surface of the upper frame 14. The two lower frames 16, 18 support the upper frame 14 from below, being arranged at a predetermined interval in the direction of arrow A and being in contact with the bottom surface of the upper frame 14. Furthermore, the two lower frames 16, 18 are each installed on an installation surface 19 via a plurality of height adjustment brackets 17.

[0013] Here, the structure of the injection molding machine 12 will be described before the detailed description of the machine base 10 according to the present embodiment.

[0014] The injection molding machine 12 includes a mold clamping device 22 for opening and closing a mold 20 and an injection device (not shown) for injecting molten resin (plastic) into the mold 20. Fig. Figure 1 shows a case where the machine base 10 supports the mold clamping device 22 from below. Here, the machine base 10 can support the injection device.

[0015] The mold clamping device 22 includes a stationary carrier (plate) 24 provided on an upper frame 14 at one end side in the direction of arrow A, a rear carrier (plate) 26 provided on the upper surface of the upper frame 14 at another end side in the direction of arrow A, a movable carrier (plate) 28 provided on the upper surface of the upper frame 14 between the stationary carrier 24 and the rear carrier 26, and a toggle mechanism 29 for moving the movable carrier 28 toward and away from the rear carrier 26 in the direction of arrow A.

[0016] The stationary support 24 and the rear support 26 are connected via four tie rods 32 that pass through the movable support 28 and extend parallel to each other in the direction of arrow A. The movable support 28 is installed on the upper surface of the upper frame 14 via a slide unit 34. The slide unit 34 is movable in the direction of arrow A along a guide rail 36 provided on the upper surface of the upper frame 14. With this arrangement, the movable support 28 is movable toward and away from the stationary support 24 in the directions of arrow A.

[0017] The mold 20 is provided between the stationary support 24 and the movable support 28. The mold 20 consists of a stationary mold (mold half) 20a and a movable mold (mold half) 20b. The stationary mold 20a is attached to the stationary support 24 on the side of the movable support 28. The movable mold 20b is attached to the movable support 28 on the side of the stationary support 24.

[0018] The toggle mechanism 29 is provided between the rear support 26 and the movable support 28. The toggle mechanism 29 includes a total of four joint connectors 30, each with two joint connectors on the upper and lower sides, cross connectors 38, and a crosshead 40. Each of the four joint connectors 30 includes a first joint rod 30a, a second joint rod 30b, a first joint pin 30c, a second joint pin 30d, and a third joint pin 30e.

[0019] One end of the first link rod 30a is pivotally connected to the movable support 28 via the first pivot pin 30c. One end of the second link rod 30b is pivotally connected to the rear support 26 via the second pivot pin 30b. Another end of the first link rod 30a and another end of the second link rod 30b are pivotally connected to each other via the third pivot pin 30e.

[0020] The second link rod 30b is connected to the crosshead 40 via the cross connector 38. The crosshead 40 has arms 42 (upper arms 42a and lower arms 42b) that extend upward and downward, respectively. The cross connectors 38 are connected to respective end portions of the arm 42. The crosshead 40 is provided on the rear bracket 26 and can move forward and backward in the directions of arrow A, guided along two guide rods (not shown) that extend in the direction of arrow A.

[0021] The mold clamping device 22 also includes a mold opening and closing mechanism 44 for opening and closing the mold 20 in the directions of arrow A (the opening / closing directions). The mold opening and closing mechanism 44 includes a mold opening and closing motor 44a, a drive pulley 44b, a belt 44c, a driven pulley 44d, a ball screw 44e, and a ball screw nut 44f. The ball screw 44e is provided along the direction of arrow A so as to extend parallel to the tie rods 32.

[0022] The drive pulley 44b can rotate together with a rotating shaft of the mold opening and closing motor 44a. The driven pulley 44d can rotate together with the ball screw 44e. The belt 44c is wound around the drive pulley 44b and the driven pulley 44d and transmits the rotating force of the drive pulley 44b to the driven pulley 44d. The ball screw nut 44f is fixed to the crosshead 40 and is threadedly engaged with the ball screw 44e. The ball screw nut 44f moves along the ball screw 44e when the ball screw 44e is rotated.

[0023] When the mold opening and closing motor 44a rotates, the rotational force is transmitted to the ball screw 44e via the drive pulley 44b, the belt 44c, and the driven pulley 44d, thereby rotating the ball screw 44e. This causes the ball screw nut 44f and the crosshead 40 to move along the guide rods in the directions of arrow A. This causes the movable carrier 28 to move in the directions of arrow A via the cross connectors 38 and the knuckle connectors 30. At this time, the ball screw 44e and the ball screw nut 44f constitute an extension and retraction mechanism 44g for advancing and retracting the crosshead 40 in the directions of arrow A.

[0024] When the movable carrier 28 is moved toward the stationary carrier 24 side, the movable mold 22b is brought into abutment against the stationary mold 20a to close the mold 20. When the movable carrier 28 is moved toward the rear carrier 26 side, the movable mold 20b moves away from the stationary mold 20a to open the mold 20.

[0025] Here, the mold clamping device 22 has an ejection mechanism (not shown) for removing a molded article (a blank) from the movable mold 20b. The ejection mechanism is provided on the movable carrier 28 on the side of the rear carrier 26 and moves an ejection pin extending in the direction of arrow A toward the side of the movable carrier 28 when the mold 20 is open to eject the molded article from the movable mold 20b.

[0026] Next, the machine base 10 which supports the injection molding machine 12 according to the present embodiment from below will be described in detail with reference to FIG. Fig. 1 to 3.

[0027] The lower frames 16, 18 of the machine base 10 are arranged along the direction of the axis A so that they form an empty lower area 46 of the mold 20. The lower frame 16 on the left side in Fig. 1 and Fig. 3 supports the bottom surface of the upper frame 14 within a range extending from a lower side of the rear support 26 to a lower side of a fixed position in a movement range of the movable support 28 in the direction of arrow A (e.g., the one shown in Fig. 1). In addition, the other lower frame 18 on the right side supports the bottom surface of the upper frame 14 from the underside of the stationary support 24. Accordingly, the two lower frames 16, 18 support the bottom surface of the upper frame 14, being spaced apart from each other by a predetermined distance in the direction of arrow A. This configuration makes it possible to remove molded articles from between the upper frame 14 and the installation surface 19 in the lower region 46 of the mold 20.

[0028] As in Fig. 1, the plurality of height adjustment brackets 17 are also provided on the bottom surfaces of the lower frames 16, 18. By adjusting the height of the plurality of height adjustment brackets 17, it is possible to adjust the height of the injection molding machine 12 arranged on the upper surface of the upper frame 14.

[0029] The upper frame 14 and the two lower frames 16, 18 are now described in detail.

[0030] As in the Fig. 1 and Fig. 2, the upper frame 14 comprises a pair of first members 14a, 14b which are rectangular columnar members and extend in the direction of arrow A, and a pair of second members 14c, 14d which are rectangular columns and extend in the direction of arrow B perpendicular to the direction of arrow A (ie, in the width direction of the machine base 10 which is perpendicular to the drawing plane in Fig. 1) and connect both ends in the direction of arrow A of the pair of first members 14a, 14b. Thus, the upper frame 14 is a rectangular frame member extending in the horizontal direction of arrow A and in the direction of arrow B. Here, the first members 14a, 14b and the second members 14c, 14d do not necessarily have to be rectangular column members, but they may also be members having an I-shaped, a C-shaped, or an H-shaped cross section. Furthermore, the first members 14a, 14b and the second members 14c, 14d may also be formed by a combination of members having a rectangular, an I-shaped, a C-shaped, and / or an H-shaped cross section.

[0031] The mold clamping device 22 (see Fig. 1) is arranged on the upper surfaces of the pair of first members 14a, 14b so as to be supported from below by the upper frame 14. Thus, when the machine base 10 is viewed in the direction of arrow A, the pair of second members 14c, 14d connect the pair of first members 14a, 14b, being in contact with the mold clamp 22. Alternatively, the two second members 14c, 14d, together with the two first members 14a, 14d, may support the mold clamp 22 from below, being in contact with the mold clamp 22. Furthermore, it would be adequate for the two first members 14a, 14b to be connected to the two second members 14c, 14d by a known method, such as welding or the like.

[0032] In this way, the upper frame 14 is a frame element that supports the mold clamping device 22 from below and creates the empty lower region 46 of the mold 20. This configuration makes it possible to guide molded articles between the upper frame 14 and the installation surface 19 to the lower region 46 of the mold 20.

[0033] As long as they do not interfere with the molded articles, the first elements 14a, 14b and the second elements 14c, 14d of the upper frame 14 can also be multiple elements. This arrangement allows the upper frame 14 to support the mold clamping device 22 from below without causing significant deflection of the upper frame 14.

[0034] As in the Fig. 1 and Fig. 3, each of the two lower frames 16, 18 comprises the pair of first elements 16a, 16b or 18a, 18b, which are rectangular columnar elements and extend in the direction of arrow A, and the pair of second elements 16c or 16d or 18c, 18d, which are rectangular columnar elements and extend in the direction of arrow A and connect the two end portions in the direction of arrow A of the pair of first elements 16a, 16b or 17a, 18b. Thus, as with the upper frame 14, each of the two lower frames 16, 18 is a rectangular frame element that extends horizontally in the direction of arrow A and in the direction of arrow B. Here, the first elements 16a, 16b, 18a, 18b and the second elements 16c, 16d, 18c, 18d do not necessarily have to be rectangular columnar elements, but they can also be elements that have an I-shaped, C-shaped or H-shaped cross-section.In addition, the first elements 16a, 16b, 18a, 18b and the second elements 16c, 16d, 18c, 18d can also each be formed by a combination of elements having a rectangular, an I-shaped, a C-shaped and / or an H-shaped cross-section.

[0035] The two lower frames 16, 18 each support the upper frame 14 from below such that the upper surfaces of the pair of first elements 16a, 16b or 18a, 18b are in contact with the bottom surfaces of the pair of first elements 14a, 14b of the upper frame 14. Therefore, when the machine base 10 is viewed in the direction of arrow A, the pair of second elements 16c, 16b or 18c, 18d connect the pair of first elements 16a, 16b or 18a, 18b to each other without being in contact with the upper frame 14. This is not shown. Alternatively, the second element 16c of the lower frame 16 may support the second element 14c of the upper frame 14 from below, and the second element 18d of the lower frame 18 may support the second element 14b of the upper frame 14 from below.Furthermore, it is appropriate that the pair of first elements 16a, 16b or 18a or 18b is connected to the pair of second elements 16c, 16d or 18c, 18d by a known method such as welding or the like.

[0036] In addition, the upper frame 14 and the two lower frames 16, 18 are each rectangular frame elements, and the two lower frames 16, 18 are arranged at a fixed distance to form the empty lower area 46 of the mold 20. As shown in Fig. Thus, as shown in Fig. 3, a space surrounded by the first two members 14a, 14b of the upper frame 14, the second member 16d of one lower frame 16 near the other lower frame 18, and the second member 18c of the other lower frame near the one lower frame 16 becomes an area constituting the empty lower portion 46 of the mold 20. Accordingly, it is possible to easily guide molded articles to the space between the upper frame 14 and the installation surface 19 in the lower portion 46 of the mold 20.

[0037] In addition, the flat surface of the two first elements 16a, 16b of one lower frame 16 is larger than the flat surface of the pair of first elements 18a, 18b of the other lower frame 18. Therefore, the contact area between the two first elements 16a, 16b of one lower frame 16 and the two first elements 14a, 14b of the upper frame 14 is larger than the contact area between the two first elements 18a, 18b of the other lower frame 18 and the two first elements 14a, 14b of the upper frame 14. As in Fig.1, one lower frame 16 supports, via the upper frame 14, the heavy components from below, such as the rear support 26, the movable support 28, the toggle mechanism 29, and the like, of the mold clamping device 22. Furthermore, the other lower frame 18 supports, via the upper frame 14, the light components from below, such as the stationary support 24, and the like. This configuration allows the two lower frames 16, 18 to support the upper frame 14 from below without causing the upper frame 14 to sag due to the load of the mold clamping device 22.

[0038] In this case, the first elements 16a, 16b, 18a, 18b and the second elements 16c, 16d, 18c, 18d of the two lower frames 16, 18 can each consist of multiple elements. In this case, too, it is possible for the two lower frames 16, 18 to support the upper frame 14 from below without causing any significant deflection of the upper frame 14.

[0039] Furthermore, in a modification of the present embodiment, the upper frame 14 can be supported from below by the one lower frame. In this case, too, it is possible to support the upper frame 14 from below without causing significant deflection of the upper frame 14. [Technical considerations arising from the design]

[0040] Technical ideas resulting from the embodiment described above are explained below.

[0041] The machine base (10) for the injection molding machine (12) comprises the upper frame (14) which supports the injection molding machine (12) from below, and the lower frame (16, 18) which supports the upper frame (14) from below, being in contact with the upper frame (14).

[0042] In this way, since no support pillar is used, the number of components is reduced. This makes it possible to reduce the working time, such as the working time for assembly and the working time for welding, in the manufacture of the machine base (10). In addition, compared to the case where the upper frame (41) is supported by support pillars, the contact area between the upper frame (14) and the lower frame (16, 18) becomes larger. This prevents deflection of the upper frame (14) due to the load of the injection molding machine (12). Accordingly, it is possible to ensure the rigidity of the machine base (10). Since no support pillar is used, it is also possible to lower the center of gravity of the machine base (10) and reduce the generation of vibrations. Accordingly, it is possible to manufacture the machine base (10) that has high rigidity and can suppress vibrations at a low cost.

[0043] The machine base (10) comprises the two lower frames (16, 18), and the two lower frames (16, 18) are arranged at a fixed distance from each other and support the upper frame (14) from below, being in contact with the upper frame (14). This configuration makes it possible to remove molded articles from the bottom of the injection molding machine (12) while ensuring the rigidity of the machine base (10).

[0044] The injection molding machine (12) includes the mold clamp (22) configured to open and close the mold (20), and the injection device configured to inject molten resin (plastic) into the mold (20). The upper frame (14) supports at least the mold clamp (22) from below. This configuration allows molded articles to be easily removed from the underside of the mold clamp (22), with the mold clamp (22) supported from below.

[0045] The two lower frames (16, 18) are arranged along an opening / closing direction A of the mold 20, providing the empty lower portion (46) of the mold (20). This configuration allows molded articles to be easily removed from the lower portion (46) of the mold (20).

[0046] The mold (20) comprises the stationary mold (20a) and the movable mold (20b). The mold clamping device (22) comprises the stationary carrier (24) to which the stationary mold (20a) is attached, the movable carrier (28) to which the movable mold (20b) is attached, the rear carrier (26), and the toggle mechanism (29) configured to move the movable carrier (28) toward and away from the rear carrier (26). Of the two lower frames (16, 18), one lower frame (16) supports the upper frame (14) in a range from a bottom surface of the rear carrier (26) to a fixed position within a range of movement of the movable carrier (28), while the other lower frame (18) supports the upper frame (14) on a bottom surface of the stationary carrier (24).This configuration makes it possible to reliably support the mold clamping device (22) while ensuring the lower portion (46) used for removing molded articles.

[0047] The upper frame (14) and the two lower frames (16, 18) each have the plurality of first elements (14a, 14b, 16a, 16b, 18a, 18b) extending along the opening / closing direction (A) of the mold (20) and the plurality of second elements (14c, 14d, 16c, 16d, 18c, 18d) extending in the direction (B) crossing the opening / closing direction (A) of the mold (20) and connecting the plurality of first elements (14a, 14b, 16a, 16b, 18a, 18b). The two lower frames (16, 18) each support the upper frame (14) from below such that the plurality of first elements (16a, 16b, 18a, 18b) of the lower frame (16, 18) are in contact with the first elements (14a, 14b) of the upper frame (14). This configuration makes it possible to support the injection molding machine (12) from below with a simple structure and to realize a design in which molded articles can be easily removed from the lower portion (46) of the mold (20).

[0048] The machine base (10) also includes the height adjustment bracket (17) mounted on a bottom surface of the lower frame (16, 18) and configured to adjust the height of the injection molding machine (12). This configuration allows the height of the injection molding machine (12) to be adjusted as desired while maintaining the rigidity of the machine base (10). List of reference symbols 10 Machine base 12 injection molding machines 14 upper frame 14a, 14b Pair of first elements 14c, 14d Pair of second elements 16, 18 lower frame 16a, 16b, 18a, 18b Pairs of first elements 16c, 16d, 18c, 18d pairs of second elements 17 Height adjustment bracket 19 Installation area 20 Shape 20a stationary mold (mold half) 20b movable mold (mold half) 22 mold clamping device 24 stationary carriers 26 rear carrier 28 movable carrier 29 Knee lever mechanism 30 joint connectors 30a first joint rod 30b second joint rod 30c first hinge pin 30d second hinge pin 30e third hinge pin 32 Drawbar 34 sliding unit 36 guide rail 38 cross connectors 40 crosshead 42 arms 42a upper arms 42b lower arms 44 Mold opening and closing mechanism 44a Mold opening and closing motor 44b Drive pulley 44c belt 44d driven pulley 44e ball screw 44f ball screw nut 44g extension and retraction mechanism 46 lower part of the form 20 A Opening / closing direction B Direction that crosses the opening / closing direction A

Claims

[1] A machine base (10) for an injection molding machine (12) comprising: an upper frame (14) which supports the injection molding machine (12) from below, and two lower frames (16, 18) which support the upper frame (14) from below, being in contact with the upper frame (14), the two lower frames (16, 18) having a fixed space, wherein the injection molding machine (12) comprises a mold clamping device (22) configured to open and close a mold (20) and an injection device configured to inject molten resin into the mold (20), wherein the upper frame (14) supports at least the mold clamping device (22) from below, characterized by , that the upper frame (14) and the two lower frames (16, 18) comprise a plurality of first elements (14a, 14b, 16a, 16b, 18a, 18b) extending along an opening / closing direction (A) of the mold (20), and a plurality of second elements (14c, 14d, 16c, 16d, 18c, 18d) extending in a direction (B) crossing the opening / closing direction (A) of the mold (20) and connecting the plurality of first elements (14a, 14b, 16a, 16b, 18a, 18b), and that the two lower frames (16, 18) each support the upper frame (14) from below such that the plurality of first elements (16a, 16b, 18a, 18b) of the lower frame (16, 18) are in contact with the first elements (14a, 14b) of the upper frame (14). [2] The machine base (10) for the injection molding machine (12) according to claim 1, wherein the two lower frames (16, 18) are arranged along an opening / closing direction (A) of the mold (20), wherein an empty lower region (46) of the mold (20) is provided. [3] The machine base (10) for the injection molding machine (12) according to claim 1 or 2, wherein the mold (20) comprises a stationary mold (20a) and a movable mold (20b), wherein the mold clamping device (22) comprises a stationary carrier (24) to which the stationary mold (20a) is mounted, a movable carrier (28) to which the movable mold (20b) is mounted, a rear carrier (26), and a toggle mechanism (29) configured to move the movable carrier (28) toward and away from the rear carrier (26), and wherein, of the two lower frames (16, 18), a lower frame (16) supports the upper frame (14) in a range from a bottom surface of the rear carrier (26) to a predetermined position within a moving range of the movable carrier (28), while another lower frame (18) supports the upper frame (14) at a bottom side of the stationary support (24). [4] The machine base for the injection molding machine (12) according to any one of claims 1 to 3, further comprising a height adjustment bracket (17) attached to a bottom surface of the lower frame (16, 18) and configured to adjust the height of the injection molding machine (12).

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