Molding machine clamping device

Abstract

To prevent deformation of a bolt at a connection portion between a pin and a toggle piece, and a connection portion between a pin and an end plate.SOLUTION: Provided is a toggle type clamping device of an injection molding machine having a toggle mechanism that extends by a vertical movement of a crosshead to clamp and move a movable platen. The toggle mechanism has a toggle link comprising a toggle piece and a face piece connected in a vertically extendable / bendable manner with a toggle pin. Both ends of the toggle link are connected to a stationary platen and an end plate with toggle pins. An end portion of a toggle pin penetrates a through hole of a support portion. The toggle pin and the support portion have a key fit to a keyway continuously formed between an end face of the toggle pin and the support portion. The support portion and the key are connected together by a bolt with an axial line parallel to the toggle pin. A deformation allowance gap is formed in the key around the bolt. The bolt is attached to the key via a deformation allowance part disposed in the deformation allowance gap.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a mold clamping device for a molding machine. [Background technology]

[0002] As described in Patent Document 1, the mold clamping mechanism of an injection molding machine performs a mold opening / closing process and a mold clamping process using a link mechanism. The link mechanism has, for example, two arms each consisting of a toggle piece and a face piece, and a hinge pin (pin). The two arms are connected to each other and to their respective movable ends (end plates) and fixed ends by the pin.

[0003] For example, the connecting portion between the pin, the support part, and the toggle piece, and the connecting portion between the pin, the support part, and the end plate are each referred to as a support part. The pin passes through a through hole in the support part. The pin and the support part are connected to the support part via a key. A key groove is formed between the end face of the pin and the end face of the support part to prevent the pin from rotating. A key fits into the key groove. The key and the pin are fixed with a bolt. The key and the support part are fixed with a bolt. This prevents the pin from slipping out of the through hole in the support part. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-112345 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional mold clamping mechanisms, when weight reduction is the goal, there is a concern that the support parts may be deformed. For this reason, an analysis was conducted on the application of clamping force to the clamping mechanism. As a result, it was revealed that deformation of the support part causes a tensile load to act on the bolt that secures the key to the end face of the support part. It was also discovered that if this tensile load becomes excessive, the bolt may break.

[0006] The present invention has been made in consideration of the above circumstances, and aims to achieve the object of preventing deformation of the bolt at the connection portion between the pin and the toggle piece and at the connection portion between the pin and the end plate. [Means for solving the problem]

[0007] (1) The mold clamping device of the molding machine of the present invention is a fixed platen fixed to the machine body; a movable platen provided above the fixed platen and fixed to upper ends of tie bars; an end plate fixed to the lower end of the tie bar below the fixed platen and movable up and down together with the movable platen relative to the fixed platen; a screw shaft that is vertically installed below the fixed platen, with its upper end journaled on the fixed platen and prevented from moving in the axial direction, and that is rotated in a circumferential direction by a drive source; A crosshead that is threadedly attached to the screw shaft so as to be movable up and down; a toggle mechanism provided between the fixed platen and the end plate, the toggle mechanism extending in response to vertical movement of the crosshead to clamp the movable platen; A toggle-type mold clamping device for a vertical injection molding machine, The toggle mechanism has toggle links interconnected by a toggle pin so as to be vertically bendable and extensible, The toggle link is connected to the fixed platen and the end plate by a toggle pin, The end of the toggle pin passes through a through hole formed in the support portion, The toggle pin and the support portion are connected by a key fitted into a key groove formed continuously on an end face of the toggle pin and the support portion, the support portion and the key are connected by a bolt having an axis parallel to the toggle pin; The key has a deformation-permitting gap formed around the bolt, and the bolt attaches the key to the support part via a deformation-permitting part disposed in the deformation-permitting gap. It is characterized by: (2) The mold clamping device of the molding machine of the present invention is the one described above in (1), The deformation allowance gap is formed between the bolt head of the bolt and the key in the axial direction of the bolt. It is possible. (3) The mold clamping device of the molding machine of the present invention is the above (2), The deformation-tolerant part is a washer. It is possible. (4) The mold clamping device of the molding machine of the present invention is the above (3), The deformation-tolerant part is a disc spring and a collar. It is possible. (5) The mold clamping device of the molding machine of the present invention is the one described above in (1), The deformation allowance gap is formed between the bolt and the key in the radial direction of the bolt. It is possible.

[0008] The mold clamping device of the molding machine of the present invention has the configuration (1) above, and even if the support part is deformed so as to tip in the axial direction of the bolt, and the bolt that secures the key to the support part moves together with the support part as the support part deforms, a deformation allowance gap is formed between the key and the bolt, and this deformation allowance gap prevents the bolt from coming into contact with the key, so no load is applied to the bolt, and therefore the bolt is not deformed or damaged. Due to the fit between the key and the groove, even if the pin rotates slightly, no load is applied to the bolt. The deformation-allowing gap can be formed only in the key.

[0009] The mold clamping device of the molding machine of the present invention has the configuration (2) above. Even if the support portion deforms in such a way that it tilts in the axial direction of the bolt, and the bolt moves in a direction that tilts it from the axis of the toggle pin, a deformation allowance gap is formed between the key and the bolt. This deformation allowance gap prevents the bolt from coming into contact with the key, and tensile loads and bending loads are not applied to the bolt. Therefore, the bolt is not deformed or damaged. At the same time, the key can prevent the toggle pin from coming out. In particular, it is preferable that the deformation allowance gap be formed around the entire periphery of the bolt in a position near the bolt head.

[0010] The mold clamping device of the molding machine of the present invention has the above-mentioned configuration (3), where the washer is positioned near the bolt head to cover the deformation allowance gap formed around the entire bolt circumference. This allows the washer to straddle the deformation allowance gap, and if the pin comes out, it can be prevented from coming out via the key. Furthermore, if a spring part is inserted inside, it also prevents damage to the spring part due to excessive deformation.

[0011] The mold clamping device of the molding machine of the present invention has the above-mentioned configuration (4), whereby the washer fills the deformation allowance gap and the disc spring is disposed inside the deformation allowance gap, thereby making it possible to provide sufficient fastening force to fix the key and the support part with the bolt even when the bolt head and the key are not in direct contact with each other. A disc spring is inserted into the deformation gap to restrict movement of the pin itself. The disc spring prevents the pin from moving and eliminating the gap. This allows the key and bolt to be kept separated. This prevents the bolt from being subjected to a tensile load. By attaching a washer to the key via a collar with the appropriate axial dimension, a controlled deformation allowance gap can be obtained, and by inserting a spring component into this gap, the amount of compression of the spring component can be controlled. This allows for control of the load applied by the spring component and prevents damage due to excessive deformation of the spring component. Furthermore, by inserting the collar, it is possible to tighten the bolt with the appropriate tightening torque.

[0012] The mold clamping device of the molding machine of the present invention has the configuration (5) above, and by forming a deformation allowance gap between the collar and the key in the radial direction around the bolt, it is possible to prevent bending load from being applied to the bolt. Even if the support part moves with the bolt due to deformation of the support part, the deformation allowance gap formed between the key and the bolt prevents the bolt from coming into contact with the key, so no load is applied to the bolt. Therefore, the bolt will not be deformed or broken.

[0013] The mold clamping device of the molding machine of the present invention makes it possible to tighten the bolt with an appropriate tightening torque by inserting a collar into the deformation allowance gap. It should be noted that a stepped bolt may be used instead of the bolt and collar. Due to the fit between the key and the groove, even if the pin rotates slightly, no load is applied to the bolt. [Effects of the Invention]

[0014] According to the present invention, it is possible to prevent tensile load and / or bending load from being applied to the bolt that secures the key to the support part, and to maintain the necessary fastening force so that the toggle pin is prevented from coming loose by the key. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a front view showing an embodiment of a molding machine according to the present invention. [Figure 2]1 is a side view showing a mold clamping device in an embodiment of a mold clamping device for a molding machine according to the present invention. [Figure 3] FIG. 2 is a front view showing the vicinity of an end face of a toggle pin in an embodiment of a mold clamping device according to the present invention. [Figure 4] 3 is an enlarged cross-sectional view showing the vicinity of end faces of a key and a toggle pin in an embodiment of a mold clamping device according to the present invention. FIG. [Figure 5] 10 is a side view illustrating clamping of a toggle pin and an end plate in an embodiment of a mold clamping device according to the present invention. FIG. [Figure 6] 1 is a side cross-sectional view illustrating a toggle pin, a key, and a support portion during mold clamping in an embodiment of a mold clamping device according to the present invention. FIG. [Figure 7] 1 is a plan cross-sectional view illustrating a toggle pin, a key, and a support portion in an embodiment of a mold clamping device according to the present invention during mold clamping. FIG. [Figure 8] 1 is a plan cross-sectional view illustrating a toggle pin, a key, and a support portion in an embodiment of a mold clamping device according to the present invention during mold clamping. FIG. [Figure 9] 1 is a plan cross-sectional view illustrating a toggle pin, a key, and a support portion in an embodiment of a mold clamping device according to the present invention during mold clamping. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] A first embodiment of a molding machine according to the present invention will be described below with reference to the drawings. Fig. 1 is a front view showing a molding machine according to this embodiment, and Fig. 2 is a side view showing a mold clamping device of the molding machine according to this embodiment, in which reference numeral 10 denotes a molding machine (injection molding machine).

[0017] As shown in Figures 1 and 2, the molding machine 10 of this embodiment has a fixed platen 1a and a table 2 fixed to a machine body 1, above which a movable platen 3 is fixed to the upper ends of tie bars 4, and below which an end plate 5 is fixed to the lower ends of tie bars 4 so as to be able to move freely up and down together with the movable platen 3 relative to the fixed platen 1a and table 2.

[0018] The end plate 5, the fixed plate 1a, the table 2, and the movable plate 3 extend substantially horizontally. The end plate 5, the fixed plate 1a, the table 2, and the movable plate 3 are substantially parallel to each other. The tie bars 4 extend substantially vertically. Multiple tie bars 4 are arranged. The multiple tie bars 4 are arranged spaced apart in the horizontal direction. A mold 7 is attached to a table 2 that is placed parallel to the fixed platen 1a. A mold 8 is attached to the movable platen 3. An injection unit 9 is connected to the mold 8.

[0019] Two sets of left and right toggle mechanisms 11 are connected to the fixed platen 1a and the end plate 5. The two sets of left and right toggle mechanisms 11 are configured to be substantially symmetrical. The toggle mechanism 11 has a toggle pin 12 , a toggle piece 13 , a toggle pin 14 , a toggle pin 15 , a face piece 16 , a connecting pin 17 , a connecting piece 18 , a connecting pin 19 , a crosshead 20 , and a screw shaft 22 .

[0020] The toggle pin 12 extends horizontally. The toggle pin 12 is attached by a support portion 50 at one end of a toggle piece 13. The end of the toggle pin 12 is inserted into a through-hole 50a of the support portion 50 (see FIG. 3). The toggle piece 13 is attached to the underside of the fixed platen 1a via the toggle pin 12. The toggle piece 13 is attached by the toggle pin 12 so that it can rotate freely up and down.

[0021] A key 40 is provided on the end face of the toggle pin 12 to prevent it from coming out. A key groove 41 is formed on the end face of the toggle pin 12 (see Figures 3 and 4). The end face of the toggle pin 12 is flush with the end face of the support part 50. A key groove 51 is formed on the end face of the support part 50. The key grooves 41 and 51 continue from the end face of the toggle pin 12 to the end face of the support part 50. The key 40 is disposed inside the key grooves 41 and 51.

[0022] The toggle pin 14 extends horizontally. The toggle pin 14 is parallel to the toggle pin 12. The toggle pin 14 is attached to the upper surface of the end plate 5 by a support portion 50 at one end of the upper part of the end plate 5. The end of the toggle pin 14 is inserted into a through hole 50a of the support portion 50 (see FIG. 3). The toggle pin 14 is located directly below the toggle pin 12 in a plan view.

[0023] A key 40 is provided on the end face of the toggle pin 14 to prevent it from coming out. A key groove 41 is formed on the end face of the toggle pin 14 (see Figures 3 and 4). The end face of the toggle pin 14 is flush with the end face of the support part 50. A key groove 51 is formed on the end face of the support part 50. The key grooves 41 and 51 are continuous from the end face of the toggle pin 14 to the end face of the support part 50. The key 40 is disposed inside the key grooves 41 and 51.

[0024] The face piece 16 is attached to the upper surface of the end plate 5 by a toggle pin 14. The face piece 16 is attached so that it can rotate freely up and down by the toggle pin 14. The toggle pin 14 is provided in the middle of the face piece 16. One end of the face piece 16 is connected to the toggle piece 13. One end of the face piece 16 is connected to the toggle piece 13 by a toggle pin 15.

[0025] The toggle pin 15 extends horizontally. The toggle pin 15 is parallel to the toggle pins 14 and 12. The toggle pin 15 is attached to a support portion 50 at one end of the toggle piece 13. The end of the toggle pin 15 is inserted into a through-hole 50a in the support portion 50 (see FIG. 3). The toggle pin 15 connects the toggle piece 13 and the face piece 16. The toggle piece 13 and the face piece 16 can be bent up and down by the toggle pin 15 .

[0026] A key 40 is provided on the end face of the toggle pin 15 to prevent it from coming out. A key groove 41 is formed on the end face of the toggle pin 15 (see Figures 3 and 4). The end face of the toggle pin 15 is flush with the end face of the support part 50. A key groove 51 is formed on the end face of the support part 50. The key grooves 41 and 51 are continuous from the end face of the toggle pin 15 to the end face of the support part 50. The key 40 is disposed inside the key grooves 41 and 51.

[0027] The connecting pin 17 extends horizontally. The connecting pin 17 is parallel to the toggle pins 15, 14, and 12. The connecting pin 17 is connected to one end of the connecting piece 18. The connecting pin 17 connects the connecting piece 18 to the crosshead 20. The connecting piece 18 is pivotally attached to the crosshead 20 by the connecting pin 17. The connecting piece 18 is pivotally attached to the crosshead 20 so as to be rotatable up and down.

[0028] The connecting piece 18 is connected to the other end of the face piece 16. The connecting piece 18 is connected to the face piece 16 by a connecting pin 19. The connecting pin 19 extends horizontally. The connecting pin 19 is parallel to the connecting pin 17, the toggle pin 15, the toggle pin 14, and the toggle pin 12. The connecting pin 19 is connected to the other end of the connecting piece 18. The connecting pin 19 is connected to the other end of the face piece 16. The crosshead 20 is attached to the nut of the screw shaft 22 .

[0029] The screw shaft 22 is journaled by a bearing 23 in the fixed platen 1a. The screw shaft 22 is prevented from moving in the axial direction. The screw shaft 22 is provided so as to be rotatable in the circumferential direction. The screw shaft 22 is provided vertically. The screw shaft 22 is preferably a ball screw shaft or a roller screw shaft. The nut of the screw shaft 22 is connected to the other end of the face piece 16 via the crosshead 20 , the connecting pin 17 , the connecting piece 18 and the connecting pin 19 .

[0030] The crosshead 20 is threadedly attached to a nut of the screw shaft 22. The crosshead 20 is guided by a plurality of guide rods (not shown) fixed vertically to the fixed platen 1a or the machine body 1. The crosshead 20 moves up and down as the screw shaft 22 rotates.

[0031] A driven pulley is attached to the end of the screw shaft 22. The driven pulley is connected to a drive pulley by a timing belt. The drive pulley is driven to rotate by a drive motor such as a servo motor. The driven pulley, drive pulley, and belt constitute a transmission mechanism that transmits the rotation of the drive motor to the screw shaft 22. The transmission mechanism may also use other transmission members such as gears.

[0032] The mounting positions of the driven pulley, driving pulley, and driving motor are not particularly limited. For example, the driven pulley may be mounted on either end of the screw shaft 22. In this case, the position of the driving motor can also be changed accordingly.

[0033] A plurality of tie bars 4 are arranged. Two or more tie bars 4 are arranged. Four tie bars 4 may be arranged. The lower ends of the tie bars 4 are threaded into adjustment nuts 4a. Rotating the adjustment nut 4a finely adjusts the gap between the movable platen 3 and the end plate 5. Rotating the adjustment nut 4a allows fine adjustment to match the thickness of the molds 7 and 8.

[0034] Key 40 is attached to toggle pin 15, toggle pin 14, and toggle pin 12, respectively. Key 40 is disposed inside keyway 41 and keyway 51 (see FIGS. 3 and 4). Key 40 extends continuously through keyway 41 and keyway 51. Key 40 is bolted to toggle pin 15, toggle pin 14, and toggle pin 12, respectively, in keyway 41. Key 40 is bolted to support part 50 in keyway 51.

[0035] Here, the key 40, key groove 41, and key groove 51 have substantially the same configurations in the toggle pin 15, toggle pin 14, and toggle pin 12. Below, the key 40, key groove 41, and key groove 51 will be described with reference to the toggle pin 14. The key 40, key groove 41, and key groove 51 in the toggle pin 15 and toggle pin 12 also have the same configurations, and so a description thereof will be omitted. The support portion 50 and the key 40 are connected by bolts 61 and 62 having axes parallel to the toggle pin 14 (see FIGS. 3 and 4).

[0036] Fig. 3 is a front view showing the vicinity of the end faces of the toggle pin and the support portion in this embodiment, and Fig. 4 is a cross-sectional view showing the vicinity of the end faces of the toggle pin and the support portion in this embodiment. As shown in Figures 3 and 4, the keyway 41 extends in the diametrical direction of the toggle pin 14. The keyway 41 is formed over the entire length of the diameter of the toggle pin 14. The keyway 51 has the same width as the keyway 41. The keyway 51 has the same depth as the keyway 41. The keyway 51 continues to the outer periphery of the support portion 50. The keyway 51 does not have to continue to the outer periphery of the support portion 50.

[0037] The key 40 is a substantially rectangular parallelepiped. Both ends of the key 40 along the key groove 51 are closer to the toggle pin 14 than the outer periphery of the key groove 51. In other words, the length of the key 40 along the key groove 41 and the key groove 51 is smaller than the length of the key groove 41 and the key groove 51.

[0038] The key 40 is fixed to the support part 50 by a bolt 61. The axis of the bolt 61 is parallel to the axis of the toggle pin 14. The key 40 is fixed to the toggle pin 14 by a bolt 62. The axis of the bolt 62 is parallel to the axis of the toggle pin 14. The axis of the bolt 61 is parallel to the axis of the bolt 62. The bolts 61 and 62 are spaced apart in the direction along the key grooves 41 and 51.

[0039] The bolts 61 are arranged one on each end of the key 40 in the direction along the key grooves 41 and 51. The bolts 62 are arranged two in the middle of the key 40 in the direction along the key grooves 41 and 51. The four bolts 61 and 62 are arranged at approximately equal intervals in the direction along the key grooves 41 and 51. The bolts 61 and 62 can be configured approximately the same.

[0040] The bolt 62 passes through a through hole 63 formed in the key 40. The bolt 62 is screwed into a female thread portion 62a formed in the toggle pin 14. The bolt 62 has a bolt head housed in a counterbore 64 formed in the key 40. The bolt 61 passes through a through hole 52 formed in the key 40. The bolt 61 is screwed into a female screw portion 61a formed in the support portion 50.

[0041] The through hole 52 has an axis parallel to the axis of the toggle pin 14. The through hole 52 is thicker than the through hole 63. The through hole 52 has a diameter equal to or larger than the bolt head of the bolt 61. An enlarged diameter portion 53 is formed in the through hole 52 at a position close to the bolt head of the bolt 61. The enlarged diameter portion 53 is formed on the surface of the key 40. The enlarged diameter portion 53 is a recess that is recessed deeper than the surface of the key 40. The diameter of the enlarged diameter portion 53 is larger than the diameter of the through hole 52. The diameter of the enlarged diameter portion 53 is larger than the diameter of the bolt head of the bolt 61. The enlarged diameter portion 53 is covered by a washer 55.

[0042] The washer 55 contacts the bolt head of the bolt 61. Together with the bolt head of the bolt 61, the washer 55 almost completely closes the through hole 52 and the enlarged diameter portion 53. The washer 55 may contact the entire periphery of the opening of the enlarged diameter portion 53. The outer diameter of the washer 55 is larger than the diameter of the opening of the enlarged diameter portion 53. The washer 55 is located farther away from the support portion 50 than a surface of the key 40 that is parallel to the end face of the toggle pin 14. The washer 55 functions as a stopper and protects the parts from the disc spring 56.

[0043] The washer 55 is spaced apart by an axial gap ΔL' from a surface of the key 40 that is parallel to the end face of the toggle pin 14. The washer 55 can be in contact with the surface of the key 40 that is parallel to the end face of the toggle pin 14. A bolt 61 passes through the washer 55. The washer 55 is a substantially annular flat plate. A disc spring 56 is housed in the expanded diameter portion 53.

[0044] The disc spring 56 is in contact with the bottom of the enlarged diameter portion 53. The disc spring 56 is in contact with the washer 55. A bolt 61 passes through the disc spring 56. The disc spring 56 is compressed in the axial direction of the bolt 61. The disc spring 56 is pressed from the bottom of the enlarged diameter portion 53 in the axial direction of the toggle pin 14. The disc spring 56 is pressed from the washer 55 in the axial direction of the toggle pin 14. The disc spring 56 is compressed in the axial direction of the toggle pin 14.

[0045] When properly compressed, the disc spring 56 has a dimension in the axial direction of the toggle pin 14 that is greater than the depth dimension of the enlarged diameter portion 53 . The outer diameter of the disc spring 56 is smaller than the diameter of the expanded diameter portion 53. The outer diameter of the disc spring 56 is smaller than the diameter of the washer 55.

[0046] A collar 57 is housed in the through hole 52. The collar 57 is cylindrical. A bolt 61 passes through the inside of the collar 57. The axial dimension of the collar 57 is slightly larger than the thickness dimension of the key 40. The axial dimension of the collar 57 is larger than the thickness dimension of the key 40 by an axial clearance ΔL'. One of the axial ends of the collar 57 contacts the washer 55. The other of the axial ends of the collar 57 contacts the end face of the support part 50. The other end of the collar 57 contacts the end face of the support part 50 around the female thread portion 61a.

[0047] The outer diameter of the collar 57 is larger than the diameter of the bolt head of the bolt 61. The outer diameter of the collar 57 is smaller than the inner diameter of the through hole 52. The outer diameter of the collar 57 is smaller than the inner diameter of the disc spring 56. The outer diameter of the collar 57 is smaller than the diameter of the expanded diameter portion 53. The outer diameter of the collar 57 is smaller than the outer diameter of the washer 55. The outer periphery of the collar 57 may be in contact with the inner periphery of the disc spring 56. One of the roles of the collar 57 is to manage the allowable deformation gap dimension by controlling the axial dimension of the collar 57 and the thickness dimension of the key 40.

[0048] The diameter of the through hole 52 is larger than the outer diameter of the collar 57 by a radial gap ΔR′. The collar 57 does not contact the inner periphery of the through hole 52. The collar 57 does not contact the key 40.

[0049] The through hole 52 and the enlarged diameter portion 53 form a deformation allowance gap. The deformation allowance gap is formed in the key 40 around the bolt 61. The washer 55, the disc spring 56, and the collar 57 constitute deformation-tolerant parts. A deformation allowance gap is formed between the bolt head of the bolt 61 and the key 40 in the axial direction of the bolt 61. A deformation allowance gap is formed between the bolt 61 and the key 40 in the radial direction of the bolt 61.

[0050] The bolt 61 attaches the key 40 to the support part 50 via a deformation-permissive part arranged in the deformation-permissive gap. The bolt 61 attaches the key 40 to the support part 50 via a deformation-permissive part covering the deformation-permissive gap. The bolt 61 attaches the key 40 to the support part 50 via a deformation-permissive part located inside the deformation-permissive gap. The bolt 61 attaches the key 40 to the support part 50 via a deformation-permissive part housed inside the deformation-permissive gap. The bolt 61 is threaded into the support part 50. The bolt 61 contacts the washer 55. The bolt 61 contacts the collar 57. The bolt 61 does not contact the key 40.

[0051] In the toggle-type mold clamping device of the electric vertical injection molding machine (molding machine) 10, the drive motor is operated to rotate the screw shaft 22 during mold clamping. When the screw shaft 22 rotates, the toggle mechanism 11 extends linearly. When the toggle mechanism 11 extends linearly, the end plate 5 descends. When the end plate 5 descends, the movable platen 3 moves downward to clamp the mold. When the movable platen 3 descends, the molds 7 and 8 approach each other between the table 2 and the mold. The molds 7 and 8 are then clamped.

[0052] More specifically, in the mold open state of the toggle-type mold clamping device of the injection molding machine 10, the toggle mechanism 11 is folded. In the mold open state, the toggle mechanism 11 is reduced in size in the up-down direction. When the toggle-type mold clamping device of the injection molding machine 10 changes from a mold open state to a mold clamped state, the drive motor is operated to rotate the screw shaft 22. The rotation of the screw shaft 22 lowers the crosshead 20. As the crosshead 20 lowers, the connecting piece 18 also lowers. The lowering connecting piece 18 presses down the inner end of the face piece 16.

[0053] As a result, the face piece 16 and the toggle piece 13 rotate around the toggle pin 14 and the toggle pin 12 as fulcrums. The face piece 16 and the toggle piece 13 rotate inward. As the face piece 16 and the toggle piece 13 rotate, the toggle pin 15 approaches the screw shaft 22. The face piece 16 and the toggle piece 13 extend and become closer to a straight line. As the toggle mechanism 11 extends linearly, the end plate 5 descends. As a result, the movable platen 3 descends together with the end plate 5. The movable platen 3 moves downward to clamp the mold. The toggle piece 13 and face piece 16 extend linearly, completing the clamping.

[0054] In the toggle-type mold clamping device of the injection molding machine 10, the toggle mechanism 11 is extended in the mold clamping state. In the mold clamping state, the toggle mechanism 11 has its maximum dimension in the vertical direction. When the toggle-type mold clamping device of the injection molding machine 10 is changed from a mold clamped state to a mold open state, the drive motor is operated to rotate the screw shaft 22. At this time, the screw shaft 22 is rotated in the opposite direction to that when the mold open state is changed to the mold clamped state. The crosshead 20 rises due to the rotation of the screw shaft 22. As the crosshead 20 rises, the connecting piece 18 also rises. The rising connecting piece 18 pushes up the inner end of the face piece 16.

[0055] As a result, the face piece 16 and the toggle piece 13 rotate around the toggle pin 14 and the toggle pin 12 as fulcrums. The face piece 16 and the toggle piece 13 rotate outward. As the face piece 16 and the toggle piece 13 rotate, the toggle pin 15 moves away from the screw shaft 22. The face piece 16 and the toggle piece 13 bend from a straight line. As the toggle mechanism 11 bends from a straight line, the end plate 5 rises. As a result, the movable platen 3 rises together with the end plate 5. The movable platen 3 moves upward to open the mold. The toggle piece 13 and face piece 16 bend, completing the mold opening.

[0056] In the toggle-type mold clamping device of this embodiment, there is no need to move a transmission mechanism or a drive motor when the movable platen 3 is opened or closed by the operation of the toggle mechanism 11, so the structure is simplified. Therefore, a highly reliable toggle-type mold clamping device that is less likely to break down can be manufactured at low cost. Also, since there are almost no structural restrictions on the rotation angles of the toggle piece 13 and the face piece 16, the opening and closing stroke of the movable platen 3 can be increased by increasing these angles.

[0057] In the toggle-type mold clamping device of this embodiment, the connecting pin 19, the connecting pin 17, the toggle pin 15, the toggle pin 14, and the toggle pin 12 each rotate when the toggle mechanism 11 is operated. The key 40 acts to prevent the toggle pin 15, the toggle pin 14, and the toggle pin 12 from rotating.

[0058] FIG. 5 is a side view illustrating clamping of the toggle pin 14 and the end plate 5 in this embodiment. In the toggle-type mold clamping device of the injection molding machine 10 of this embodiment, during mold clamping, a mold clamping force is applied from the face piece 16 to the end plate 5 as shown by the arrows in Fig. 2. This causes the end plate 5 in the toggle mechanism 11 to deform as shown schematically in Fig. 5. That is, in Fig. 5, the end plate 5 deforms so that both left and right ends point upward and the center of the end plate 5 in the left-right direction descends. Alternatively, the mold clamping force is applied to the end plate 5 in a direction that causes deformation as shown in Fig. 5.

[0059] Fig. 6 is a side cross-sectional view illustrating the toggle pin 14, the key 40, and the support portion 50 of this embodiment when clamping. Fig. 7 is a plan cross-sectional view illustrating the toggle pin 14, the key 40, and the support portion 50 of this embodiment when clamping. At this time, the support portion 50 deforms in accordance with the deformation of the end plate 5 shown in FIG. Modifications of the support portion 50 are shown in FIGS.

[0060] In Fig. 6, the support portion 50 before deformation is shown by a solid line. In Fig. 6, the support portion 50A after deformation is shown by a dashed line. For the sake of explanation, Fig. 7 shows a configuration in which bolt 61A, the same as bolt 62, is used instead of bolt 61, that is, a state in which there is no deformation-permitting gap or deformation-permitting part. In Figs. 6 and 7, the direction of deformation is indicated by an arrow.

[0061] The support portion 50A is deformed so that the upper end falls to the left in Fig. 6. The support portion 50A is deformed so that it moves in a direction away from the key 40 in Fig. 7. At this time, it is considered that the support portion 50A deforms relative to the support portion 50 with a maximum deformation amount ΔL near the key 40, as shown in FIGS.

[0062] As a result, bolt 61A, which is threaded into support part 50, tries to move together with deformed support part 50A. That is, bolt 61A tries to move so that the right end falls to the left in Figure 6. Bolt 61A tries to move leftward in Figure 7.

[0063] In contrast, the toggle pin 14 does not follow the deformation of the end plate 5 . Therefore, the bolt 62 threaded into the toggle pin 14 does not follow the deformation of the end plate 5. In FIG. 6, the right end of the bolt 62 does not move to the left. In FIG. 7, the bolt 62 does not move leftward. As a result, the key 40 fixed to the toggle pin 14 by the bolt 62 also does not follow the deformation of the end plate 5. It does not move to the left.

[0064] Both bolt 61A and bolt 62 pass through key 40. Therefore, even if bolt 61A attempts to move leftward, the key, which is fixed by bolt 62, which does not move, prevents the bolt 61A from moving. At this time, bolt 61A is pulled leftward. In other words, a tensile load is applied to bolt 61A.

[0065] Fig. 8 is a cross-sectional plan view illustrating the toggle pin 14, the key 40, and the support portion 50 of this embodiment when the mold is opened. Fig. 9 is a cross-sectional plan view illustrating the toggle pin 14, the key 40, and the support portion 50 of this embodiment when the mold is closed. In contrast to a configuration without a deformation allowance gap and a deformation allowance part, in a configuration in which the key 40 has a deformation allowance gap and a deformation allowance part, a gap ΔL' is formed in advance when no mold clamping force is applied, as shown in Fig. 8. In other words, an axial clearance (gap) ΔL' is formed as a deformation allowance gap.

[0066] The gap ΔL' is the difference between the axial dimension of the collar 57 and the thickness dimension of the key 40. The axial dimension of the collar 57 is larger than the thickness dimension of the key 40 by the axial gap ΔL'. As a result, the washer 55 is spaced apart by the axial gap ΔL' from the surface of the key 40 that is parallel to the end face of the toggle pin 14.

[0067] The bolt 61, which is threaded into the support part 50, presses the washer 55 toward the support part 50 with the bolt head. The washer 55 is in contact with the collar 57. The collar 57 is in contact with the end face of the support part 50. In this state, the bolt 61 is fixed to the support part 50. At the same time, the washer 55 is in contact with the disc spring 56. The disc spring 56 is in contact with the bottom part of the enlarged diameter part 53. The disc spring 56 is compressed in the axial direction of the bolt 61.

[0068] The bolt 61 threaded into the support part 50 presses against the key 40 via the bolt head, washer 55, disc spring 56, and the bottom of the enlarged diameter part 53. This connects the support part 50 and the key 40. At this time, the washer 55 is pressed by the disc spring 56 in a direction that relaxes it from the support part 50. The washer 55 is sandwiched between the bolt head of the bolt 61 and a collar 57.

[0069] On the other hand, the bolt 62 screwed into the toggle pin 14 has its bolt head pressing against the bottom of the countersunk hole 64. This fixes the toggle pin 14 and the key 40 together. These connect the support portion 50 and the toggle pin 14 via the key 40 .

[0070] When a mold clamping force is applied, the support portion 50A moves to the left as shown in Fig. 9. This causes a distance of a maximum deformation amount ΔL between the support portion 50A and the key 40. Note that, because the support portion 50A deforms to tilt, the maximum value of the distance between the support portion 50A and the key 40 is the maximum deformation amount ΔL.

[0071] At this time, bolt 61 threaded into support part 50A moves to the left together with support part 50A. Collar 57 moves to the left together with support part 50A. Washer 55 sandwiched between the bolt head of bolt 61 and collar 57 moves to the left together with support part 50A.

[0072] The bolt 61 moves in the axial direction by a distance corresponding to the maximum deformation amount ΔL. The collar 57 moves in the axial direction by a distance corresponding to the maximum deformation amount ΔL. The washer 55 moves in the axial direction by a distance corresponding to the maximum deformation amount ΔL.

[0073] In addition, the bolt 61 is inclined so that its axis is inclined integrally with the support portion 50A. The collar 57 is inclined so that its axis is inclined integrally with the support portion 50A. The washer 55 is inclined so that its axis is inclined integrally with the support portion 50A.

[0074] In a configuration in which the key 40 has a deformation allowance gap, even if the bolt 61 moves, it will not come into contact with the key 40. In a configuration in which the key 40 has a deformation allowance gap, even if the bolt 61 is tilted, it will not come into contact with the key 40. Furthermore, in a configuration equipped with a deformation-tolerant component, the axial movement of the bolt 61 is absorbed by the elastic deformation of the disc spring 56. That is, as the bolt 61 moves axially, the washer 55 moves in the axial direction of the bolt 61. The washer 55 moves in the axial direction of the bolt 61 by a distance corresponding to the maximum deformation amount ΔL. The washer 55 moves closer to the support portion 50 in the axial direction of the bolt 61 by a distance corresponding to the maximum deformation amount ΔL. The washer 55 tilts in accordance with the tilt of the bolt 61.

[0075] In contrast, the key 40 that is not in contact with the bolt 61 does not follow these movements. The axial movement of the washer 55 further compresses the disc spring 56. The tilt of the washer 55 further compresses the disc spring 56. However, the washer 55 is spaced apart all around its circumference from a surface of the key 40 that is parallel to the end face of the toggle pin 14 by an axial clearance ΔL'. If the axial movement distance corresponding to the maximum deformation amount ΔL of the washer 55 is smaller than the axial clearance ΔL', the washer 55 will not come into contact with the key 40.

[0076] In other words, ΔL' - ΔL > 0 If this is the case, the washer 55 does not come into contact with the key 40. Therefore, the load caused by the deformation of the support portion 50A is not applied to the bolt 61. For this reason, the present inventors ΔL' - ΔL > 0 The axial clearance ΔL' was set as the allowable deformation gap so that

[0077] Here, the axial clearance ΔL' formed in the key 40 as a deformation allowance gap is set larger than the maximum deformation amount ΔL. The maximum deformation amount ΔL is determined based on the analysis results of a simulation of the deformation of the end plate 5 due to the mold clamping force. Therefore, contact between the washer 55 and the key 40 can be prevented regardless of differences in the size, type, and machine differences of the molding machine 10, the magnitude of the mold clamping force, etc. In other words, the application of the deformation load of the support portion 50A to the bolt 61 can be prevented. The bolt 61 can be prevented from being deformed. The bolt 61 can be prevented from being damaged.

[0078] While the axial clearance ΔL' has been described so far as a deformation allowance gap, the function of preventing contact between the key 40 and the bolt 61 is the same for the radial clearance ΔR'. In this case, even if the bolt moves or tilts due to the movement, deformation, or tilt of the support portion 50, the radial clearance ΔR' is formed as a deformation allowance gap, so that the collar 57 does not come into contact with the through hole 52. As a result, in a configuration that includes a deformation allowance gap and a deformation allowance component, it is possible to similarly prevent the application of deformation load to the bolt 61. It is possible to prevent the bolt 61 from being deformed. It is possible to prevent the bolt 61 from being damaged.

[0079] According to this embodiment, an axial gap ΔL' is provided between the key 40 and the bolt 61, and even if deformation occurs, the bolt 61 is not pulled by this gap. Therefore, no tensile load is generated in the bolt 61. The collar 57 and washer 55, whose dimensions are controlled, are fixed to the support part 50 by the bolt 61. This makes it possible to ensure the gap ΔL' required for the design.

[0080] By adopting a configuration in which the washer 55 or the disc spring 56 abuts against the key 40, it is possible to prevent the disc spring 56 from being damaged and to maintain the function of preventing the toggle pin 14 from coming out. When the washer 55 contacts the key 40, the required gap ΔL' can be obtained by controlling the dimensions of the contact surface between the washer 55 and the key 40. However, it is desirable to set the required gap ΔL' by controlling the dimensions of the contact surface between the washer 55 and the key 40 so that they do not come into contact with each other. Basically, the washer 55 and the key 40 do not come into contact with each other. Furthermore, by adopting a configuration in which the collar 57 is inserted into the through hole 52, it becomes possible to tighten the bolt 61 with an appropriate tightening torque. Moreover, the bolt 61 can be kept out of contact with the key 40.

[0081] By providing a radial gap ΔR' between the collar 57 and the through hole 52, it is possible to prevent a bending load from being applied to the bolt 61. This also makes it possible to deal with complex deformations that may occur in the support portion 50. Furthermore, due to the fit between the key 40 and the key grooves 41, 51, it is possible to prevent a load from being applied to the bolt 61 even if the toggle pin 14 rotates slightly.

[0082] If the toggle pin 14 itself moves axially and the gap ΔL' disappears, a tensile load will be generated in the bolt 61. In response to this, in this embodiment, the disc spring 56, which is a spring component, is housed in the gap, which is the expanded diameter portion 53. As a result, the disc spring 56 presses the toggle pin 14 via the key 40, restricting movement of the toggle pin 14, thereby maintaining the gap ΔL'.

[0083] By setting the axial dimension of collar 57, the dimension of the washer contact surface of key 40, and the depth dimension of expanded diameter portion 53 that houses disc spring 56, it is possible to control gap ΔL' and the compression amount of disc spring 56 at the same time. This makes it possible to control the load applied to key 40 by disc spring 56 and prevent damage to disc spring 56 due to excessive deformation.

[0084] The present invention makes it possible to: - The collar acts as a deformation-tolerant part, allowing the bolt to be tightened with the appropriate tightening torque. -Controlled gaps ΔL' and ΔR' are formed in the axial and radial directions of the bolt, respectively, preventing the occurrence of both tensile loads and bending loads on the bolt. -Controls the load on the spring component, which is a deformation-tolerant component, and also protects the spring component.

[0085] The present invention has the following advantages. -Prevents bolt breakage. This can be achieved without making any design changes to the existing molding machine or toggle mechanism. This can be achieved by replacing the key and bolt, and adding only the collar, washer, and spring parts. Costs can be kept to a minimum. Modification of existing equipment can also be carried out relatively easily.

[0086] Furthermore, in the present invention, it is also possible to individually select and combine the individual configurations in the above-described embodiments.

[0087] In this embodiment, the configuration includes the bolt 61 and the collar 57, but the configuration is not limited to this. For example, a stepped bolt can be used instead of the bolt 61 and the collar 57. In this case, it is preferable that the stepped bolt does not come into contact with the through hole 52. Furthermore, even if the collar 57 is not present, the washer 55 is pressed by the disc spring 56, so that it is in a position where it comes into contact with the bolt head of the stepped bolt, and the same effect can be achieved. [Explanation of symbols]

[0088] 1...Machine body 1-1…Fixed plate 2. Table 3…Movable plate 4...Tie bar 5...End plate 7,8…Mold 10...Molding machine 11...Toggle mechanism 12, 14, 15...Toggle pins 13...Toggle piece 16...Facepiece 17...Connecting pin 18...Connecting piece 20...Crosshead 22...Screw shaft 40...key 50,50A…Support part 50a...Through hole 52...Through hole (deformation allowance gap) 53...Expanded diameter section (deformation allowance gap) 55...Washer (deformable part) 56...Disc spring (deformable part) 57...Collar (deformable part) 61...Bolt ΔL' ... Gap (allowable deformation gap) ΔR' ... Gap (allowable deformation gap)

Claims

1. a fixed platen fixed to the machine body; a movable platen provided above the fixed platen and fixed to upper ends of tie bars; an end plate fixed to the lower end of the tie bar below the fixed platen and movable up and down together with the movable platen relative to the fixed platen; a screw shaft that is vertically installed below the fixed platen, with its upper end journaled on the fixed platen and prevented from moving in the axial direction, and that is rotated in a circumferential direction by a drive source; A crosshead that is threadedly attached to the screw shaft so as to be movable up and down; a toggle mechanism provided between the fixed platen and the end plate, the toggle mechanism extending in response to vertical movement of the crosshead to clamp the movable platen; A toggle-type mold clamping device for a vertical injection molding machine, The toggle mechanism has toggle links interconnected by a toggle pin so as to be vertically bendable and extensible, The toggle link is connected to the fixed platen and the end plate by a toggle pin, The end of the toggle pin passes through a through hole formed in the support portion, The toggle pin and the support portion are connected by a key fitted into a key groove formed continuously on an end face of the toggle pin and the support portion, the support portion and the key are connected by a bolt having an axis parallel to the toggle pin; The key has a deformation-permitting gap formed around the bolt, and the bolt attaches the key to the support part via a deformation-permitting part disposed in the deformation-permitting gap. A mold clamping device for a molding machine.

2. The deformation allowance gap is formed between the bolt head of the bolt and the key in the axial direction of the bolt.

2. The mold clamping device for a molding machine according to claim 1.

3. The deformation-tolerant part is a washer.

3. The mold clamping device for a molding machine according to claim 2.

4. The deformation-tolerant part is a disc spring collar.

4. The mold clamping device for a molding machine according to claim 3.

5. The deformation allowance gap is formed between the bolt and the key in the radial direction of the bolt.

2. The mold clamping device for a molding machine according to claim 1.

Images