JP2017071058A - Vertical injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertical injection molding machine having a large mold opening/closing stroke and capable of suppressing the height of a stationary platen.SOLUTION: A vertical injection molding machine (1) comprises a stationary platen (5), an upper movable platen (6), a lower movable platen (7), tie bars (9), and a toggle mechanism (10). In a ball screw mechanism for driving the toggle mechanism (10), the tip of a ball screw (23) is fixed to a crosshead (19), a ball nut (24) screwed with the ball screw (23) fixes a sleeve body (29) integrally with its lower part, and the sleeve body (29) is borne in the lower movable plate (7). In the crosshead (19), the height of a fixing portion to which the ball screw (23) is fixed is made higher than that of a connecting portion connected with crosslinks (18, 18), and a storage space (26) is formed under the fixing portion. When the toggle mechanism (10) is bent, the tip of the ball nut (24) is stored in the storage space (26).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vertical injection molding machine provided with a toggle type mold clamping mechanism.

  A vertical injection molding machine is well known in the art, and generally includes a mold clamping device that opens and closes a pair of molds in the vertical direction and an injection device that injects a molten resin into the clamped mold. In the vertical injection molding machine, the mold opens up and down, so it does not fall even if an insert is inserted into the mold. Therefore, it is suitable for so-called insert molding. Also, the vertical injection molding machine has the advantage that it can be easily installed in a limited factory space due to its small installation area.

JP 2006-327131 A

  Although the mold clamping device of the vertical injection molding machine includes a direct pressure type clamping apparatus, a vertical injection molding machine including a toggle type clamping mechanism is also well known, and has been proposed by various patent documents such as Patent Document 1, for example. ing. As shown in FIG. 3A, a vertical injection molding machine 51 having a toggle type mold clamping mechanism slides on a stationary platen 52 supported by a plurality of support columns, and the stationary platen 52. A plurality of tie bars 53, 53 penetrating vertically freely, an upper movable plate 55 fixed to the upper end of the tie bars 53, 53 and opened and closed with respect to the fixed plate 52, and tie bars 53, 53 The lower movable platen 56 is fixed to the lower end of the lower platen by a predetermined mold thickness adjusting mechanism, and the toggle mechanism 58 is provided between the fixed platen 52 and the lower movable platen 56. The fixed plate 52 is provided with a lower mold 59 on its upper surface, and the upper movable plate 55 is provided with an upper mold 60 on its lower surface. In FIG. 3A, the left half of the machine center line CL indicates the mold-clamping state and the right half indicates the mold-open state. As shown in the left half, the toggle extends the toggle mechanism 58. When driven in the direction, the lower movable platen 56 is driven downward with respect to the fixed platen 52, and the upper movable platen 55 connected to the lower movable platen 56 by the tie bars 53, 53 is also driven downward, thereby a pair of molds. 59 and 60 are clamped. 3A, when the toggle mechanism 58 is driven in the direction in which the toggle is folded, the vertical movable plates 55 and 56 are driven upward with respect to the fixed plate 52 to open the mold. The

  The vertical injection molding machine 51 shown in FIG. 3A is provided with a ball screw mechanism 62 for driving a toggle mechanism 58 as follows. That is, the ball screw 63 constituting the ball screw mechanism 62 is rotatably supported by a predetermined bearing mechanism 65 provided on the lower movable plate 56 in a state where movement in the axial direction is restricted. The ball screw 63 is rotated by a driving mechanism not shown in the drawing. A ball nut 66 screwed into the ball screw 63 is fixed to a cross head 68 that drives the toggle mechanism 58. In such a toggle mechanism 58, when the ball screw 63 is rotated in the forward and reverse directions to open and close the die, the width of the vertical movement of the cross head 68 is relatively small, but the ball screw 63 together with the lower movable plate 56 Since it moves up and down, the range of vertical movement is large.

  3A shows a vertical injection molding machine 51 ′ similar to the vertical injection molding machine 51 shown in FIG. 3A, which is the same as the vertical injection molding machine 51. The same reference numerals are given to the members. Also in (a) of FIG. 3, the left half of the machine center line CL indicates the mold clamping state, and the right half indicates the mold open state. This vertical injection molding machine 51 'is provided with a ball screw mechanism 62' for driving a toggle mechanism 58 as follows. That is, the ball screw 63 ′ constituting the ball screw mechanism 62 ′ is in a state in which the tip end portion is fixed to the cross head 68 and cannot be rotated and moved in the axial direction. A ball nut 66 ′ screwed into the ball screw 63 ′ is rotatably provided on the lower movable plate 56 via a predetermined bearing mechanism 65 ′. The ball nut 66 'is rotated by a driving mechanism not shown in the drawing. In such a toggle mechanism 58, when the ball nut 66 ′ is rotated in the forward direction and the reverse direction to open and close the mold, the width of the vertical movement of the cross head 68 is relatively small, and the ball fixed to the cross head 68 The width of the vertical movement of the screw 63 ′ is also relatively small.

  Even in the vertical injection molding machine 51 shown in (a) of FIG. 3 or the vertical injection molding machine 51 ′ shown in (a) of FIG. Since the mold can be opened and closed in the vertical direction, there is no problem in performing insert molding, for example. However, there are also problems to be solved for the conventional vertical injection molding machines such as the vertical injection molding machines 51 and 51 '. Specifically, this is a problem regarding the height h of the fixed platen 52. Similar to a general horizontal injection molding machine, a vertical injection molding machine is required to be able to mold a large molded product. To that end, it is important to secure a large mold opening / closing stroke. . In the vertical injection molding machines 51, 51 ′, the mold opening / closing stroke is determined by the vertical movement width of the lower movable board 56. If only the width of the vertical movement of the lower movable board 56 is increased, the toggle mechanism 58 may be simply enlarged. However, when the toggle mechanism 58 is increased in size, the height h of the stationary platen inevitably increases. This makes it difficult for an operator who maintains the molds 59 and 60 in the vertical injection molding machines 51 and 51 '. Therefore, a method of simply increasing the size of the toggle mechanism 58 cannot be adopted. Therefore, for example, it is conceivable to increase the bending / extension ratio by devising the shape of the toggle mechanism 58 to increase the difference in height between the extended state and the bent state. As a result, it is likely that a large range of vertical movement of the lower movable plate 56 can be secured even with a relatively small toggle mechanism. However, such a response cannot be taken simply. Alternatively, even if a countermeasure is taken, the height h of the fixed platen 52 does not become sufficiently low. First, considering the case of the vertical injection molding machine 51 shown in FIG. 3A, the ball screw 63 moves up and down integrally with the lower movable platen 56 when the mold is opened and closed as described above. Sometimes, there is a restriction that the upper end of the ball screw 63 must be prevented from hitting the fixed platen 52. Because of such restrictions, it is difficult to increase the bending rate of the toggle mechanism 58. This is because if the bending rate is increased, the ball screw 63 moves upward by that amount and collides with the stationary platen 52 when the mold is opened. From the above, in the vertical injection molding machine 51 in which the ball screw 63 is rotatably provided on the lower movable plate 56, it is difficult to adopt the toggle mechanism 58 having a large bending rate, and the height h of the fixed plate 52 is sufficiently low. I can't understand. Next, considering the case of the vertical injection molding machine 51 ′ shown in FIG. 3A, in this vertical injection molding machine 51 ′, as described above, the width of the vertical movement of the ball screw 63 ′. Is relatively small in mold opening and closing. That is, there is no fear that the upper end of the ball screw 63 ′ hits the fixed platen 52. However, there are two problems. The first problem is that the distance 70 or the interval 70 between the upper end of the ball screw 63 'and the fixed platen 52 is large, and this interval 70 is useless. In general, since the cross head 68 is positioned substantially at the center of the ball screw mechanism 62, the vertical injection molding machine 51 ′ in which the upper end of the ball screw 63 is fixed to the cross head 68 has a certain size and the interval 70. Will be secured. Therefore, even if the toggle mechanism 58 having a high bending rate is employed, the height h of the stationary platen 52 does not decrease by the interval 70. The second problem is interference between the cross head 68 and the ball nut 66 '. When the mold is opened, the cross head 68 is close to the ball nut 66 ′. However, when the toggle mechanism 58 having a high bending rate is employed, they collide with each other. In order to prevent the cross head 68 and the ball nut 66 'from colliding when the mold is opened, the mounting position on the lower movable plate 56 of the ball nut 66' may be made as low as possible. Since 66 'protrudes from below the lower movable board 56, the problem of interference with the floor surface occurs. That is, the mounting position of the ball nut 66 'on the lower movable plate 56 cannot be lowered so much. Therefore, the height h of the fixed platen 52 cannot be sufficiently reduced. Further, since the ball nut 66 'has a large diameter, the bearing mechanism 65' for bearing the ball nut 66 'in a rotatable manner inevitably increases in size. When the size is increased, the bearing mechanism 65 ′ protrudes downward from the lower movable platen 56, and this also causes the height h of the fixed platen 52 not to be lowered sufficiently.

  An object of the present invention is to provide a vertical injection molding machine that solves the above-described problems. Specifically, the height of the stationary platen is ensured even though a sufficient mold opening / closing stroke can be secured. It is an object of the present invention to provide a vertical injection molding machine that can be made low, thereby facilitating maintenance work by an operator.

  In order to achieve the above object, the present invention is configured as a vertical injection molding machine equipped with a toggle type mold clamping device. The vertical injection molding machine includes a fixed platen, an upper movable platen, a lower movable platen, a tie bar connecting the upper and lower movable plates, and a toggle mechanism provided between the lower movable platen and the fixed platen. The toggle mechanism includes a pair of upper links pivotally supported by the fixed platen, a pair of lower links pivotally supported by the lower movable platen, a cross link, a cross head, and a ball screw mechanism. . The upper link and the lower link are rotatably connected to each other, and the cross link is connected to one or both of the upper link and the lower link and to the connecting portion of the cross head. The ball screw of the ball screw mechanism is fixed to the cross head. The cross head is formed so that the fixed portion is higher than the connecting portion of the cross link. Further, a storage space having a predetermined size is formed below the fixed portion, and at least the tip of the ball nut is stored when the toggle mechanism is bent.

Thus, in order to achieve the above object, the invention according to claim 1 is a fixed platen to which a lower mold is attached, and an upper movable plate that is disposed above the fixed platen and to which an upper mold is attached; A lower movable plate disposed below the fixed plate, a plurality of tie bars that are inserted through the fixed plate and connect the upper movable plate and the lower movable plate, the fixed plate, and the lower movable plate In the vertical injection molding machine comprising a toggle mechanism provided between, a pair of upper links, a pair of lower links, a pair of cross links, a cross head, and a ball screw mechanism The upper link and the lower link each have one end portion pivotally supported by each of the fixed platen and the lower movable platen, and the other end portions are rotatable. Connected, the cross-link One end is rotatably connected to the upper link and / or the lower link, and the other end is rotatably connected to the crosshead. A tip of a ball screw constituting a screw mechanism is fixed to the cross head, and a ball nut screwed to the ball screw is rotatably provided on the lower movable plate, and the cross head includes the ball screw. When the fixed portion that is fixed is higher than the connecting portion connected to the cross link, and a storage space of a predetermined size is formed below the fixed portion, and the toggle mechanism is bent Further, at least the tip end portion of the ball nut is stored in the storage space.
According to a second aspect of the present invention, in the vertical injection molding machine according to the first aspect, a cylindrical sleeve body is integrally fixed to a lower portion of the ball nut, and the sleeve body is rotatable. A vertical injection molding machine is provided which is provided on the lower movable platen.

  As described above, the present invention is configured as a vertical injection molding machine provided with a toggle mechanism. In the ball screw mechanism constituting the toggle mechanism, the ball screw is fixed to the cross head, and the ball nut is rotatably provided on the lower movable platen. Since the ball screw mechanism is provided as described above, the vertical injection molding machine according to the present invention has a relatively small vertical movement width when the ball nut is rotated to open and close the toggle mechanism. According to the present invention, in the cross head, the fixing portion for fixing the ball screw is higher than the connecting portion connected to the cross link. That is, the fixing portion of the ball screw is located at a relatively high position in the toggle mechanism. Then, the distance or distance between the tip of the ball screw and the fixed platen is narrow. In vertical injection molding machines where the vertical movement of the ball screw is relatively small, the height of the fixed platen is affected by the gap between the tip of the ball screw and the fixed platen. The height can be lowered. According to the present invention, the crosshead has a storage space of a predetermined size formed below the fixed portion, and when the toggle mechanism is bent, at least the tip of the ball nut is stored in the storage space. ing. This solves the problem that occurs when a toggle mechanism with a high bending rate is employed, that is, the problem of interference between the crosshead and the ball nut. As a result, the vertical injection molding machine according to the present invention can adopt a toggle mechanism that is relatively small and has a high bending rate, and ensures a large mold opening / closing stroke while keeping the height of the fixed platen low. be able to. According to another invention, a cylindrical sleeve body is integrally fixed to a lower portion of the ball nut, and the sleeve body is rotatably provided on the lower movable platen. Since it is configured in this way, the following two effects can be obtained. The first effect is that the length of the ball screw can be shortened because the ball nut can be provided at a relatively high position with respect to the lower movable platen. As a result, the height of the fixed plate can be further reduced. Since the sleeve body is cylindrical, the ball screw penetrates the inside of the toggle mechanism when it is bent. The second effect is that the bearing mechanism that is rotatably supported by the lower movable platen can be reduced in size. Since the ball nut must secure a path for the rolling ball, the outer diameter inevitably increases, but the sleeve body only needs to have a ball screw inserted inside. Has a high degree of freedom. If the outer diameter is made smaller than the ball nut, the bearing mechanism for bearing the sleeve body can be reduced in size. If a small bearing mechanism is employed, the height of the bearing mechanism protruding from below the lower movable plate can be reduced, and the height of the fixed plate can be further reduced.

It is a front view which shows the vertical type injection molding machine which concerns on embodiment of this invention of the mold clamping state in a partial cross section. It is a front view which shows the vertical type injection molding machine which concerns on embodiment of this invention of a mold open state in a partial cross section. It is a figure which shows the conventional vertical injection molding machine, The (a), (b) is a front view which shows two types of conventional vertical injection molding machines from which the attachment method of the ball screw mechanism in a toggle mechanism differs. .

  Hereinafter, this embodiment will be described. A vertical injection molding machine 1 according to the present embodiment includes a mold clamping device 2 and an injection device 3 provided on the upper part of the mold clamping device 2. The mold clamping device 2 includes a fixed platen 5 supported by the columns 4 and 4, an upper movable platen 6 disposed above the fixed platen 5, and a lower movable platen disposed below the fixed platen 5. Between the fixed platen 5 and the lower movable platen 7, slidably penetrating the fixed platen 5 and connecting the upper movable platen 6 and the lower movable platen 7. The toggle mechanism 10 is provided. A lower mold 12 is provided on the upper surface of the fixed platen 5 and an upper mold 13 is provided on the lower surface of the upper movable platen 6 so that when the toggle mechanism 10 is driven, these molds 12 and 13 are clamped. It has become. The upper movable plate 6 has a hollow 6a at the center, the injection device 3 is inserted from above, and the injection nozzle of the injection device 3 is in contact with a sprue (not shown) of the upper mold 13.

  In the vertical injection molding machine 1 according to the present embodiment, the height of the stationary platen 5 is kept low despite a large mold opening / closing stroke being ensured, but this can be realized. This is because the toggle mechanism 10 has a feature. The toggle mechanism 10 according to the present embodiment will be described.

  The toggle mechanism 10 includes a pair of upper links 15 and 15, a pair of lower links 16 and 16, a pair of cross links 18 and 18, a cross head 19, and a ball screw mechanism. One end of each of the upper links 15, 15 is pivotally supported by the fixed platen 5, and one end of each of the lower links 16, 16 is pivotally supported by the lower movable platen 7. The other ends of the upper links 15 and 15 and the lower links 16 and 16 are connected to each other by pins 21 and 21 so as to be rotatable. In the toggle mechanism 10 according to the present embodiment, the cross links 18, 18 are also connected at one end thereof by the pins 21, 21. The other ends of the cross links 18 and 18 are rotatably connected to a cross head 19 according to the present embodiment, which will be described in detail later. In the toggle mechanism 10 according to the present embodiment, the upper links 15 and 15 are shorter than the lower links 16 and 16. The position where the upper links 15 and 15 are pivotally supported in the fixed platen 5 is closer to the machine center, that is, the inside than the position where the lower links 16 and 16 are pivotally supported in the lower movable platen 7. Yes. Since it is configured in this way, although not described in detail, the toggle mechanism 10 according to the present embodiment has a large bending rate. Accordingly, the vertical injection molding machine 1 according to the present embodiment employs a relatively small toggle mechanism 10, but a large mold opening / closing stroke can be obtained.

  The toggle mechanism 10 according to the present embodiment is driven by a ball screw mechanism. A ball screw 23 constituting a ball screw mechanism is fixed to the center portion of the cross head 19 at the tip thereof. A ball nut 24 screwed into the ball screw 23 is rotatably provided on the lower movable platen 7. Therefore, when the ball nut 24 is rotated in the forward direction and the reverse direction by a drive mechanism not shown in the drawing, the ball screw 23 is driven in the axial direction, and the toggle mechanism 10 is bent and extended.

  The crosshead 19 according to the present embodiment is characterized by its shape. The cross head 19 is formed so that the fixed portion to which the ball screw 23 is fixed is at a higher position than the connecting portions on both sides to which the cross links 18 and 18 are connected. A cylindrical cutout 26 is opened below the fixed portion. The cutout 26 is a storage space 26 in which the upper portion of the ball nut 24 is stored when the toggle mechanism 10 is bent. Since the crosshead 19 is formed in this way, it has two features. The first feature is that the distance 28 between the crosshead 19 and the stationary platen 5, in other words, the distance 28 between the upper end of the ball screw 23 and the stationary platen 5 is shortened. Since the interval 28 is shortened, there is no wasted space and the height of the stationary platen 5 can be reduced. The second feature is that since the ball nut 24 is stored in the storage space 26, the crosshead 19 can be sufficiently driven toward the lower movable platen 7. That is, a large vertical distance that can drive the crosshead 19 can be secured. Thus, the toggle mechanism 10 can be sufficiently extended or bent without hindering the bending rate of the toggle mechanism 10.

  The vertical injection molding machine 1 according to the present embodiment is also characterized by a method of attaching the ball nut 24 in the lower movable platen 7. In the present embodiment, the ball nut 24 is integrally provided with a cylindrical sleeve body 29 at the lower portion thereof. The sleeve body 29 has an inner diameter slightly larger than the diameter of the ball screw 23 so that the ball screw 23 can be inserted therethrough. Such a sleeve body 29 is rotatably provided on the lower movable plate 7 via a bearing mechanism 31. Since it is configured in this way, the ball nut 24 is provided not at the lowermost part of the lower movable panel 7 but at a slightly higher position. Thus, since the ball nut 24 is provided at a slightly high position, the ball screw 23 can be shortened accordingly. As a result, the height of the fixed platen 5 can be reduced.

  FIG. 2 shows a state where the toggle mechanism 10 is bent and the mold is opened in the vertical injection molding machine 1 according to the present embodiment. When the toggle mechanism 10 is bent, the tip of the ball nut 24 is stored in the storage space 26 of the cross head 19 and is sufficiently bent. The ball screw 23 penetrates through the sleeve body 29 and protrudes downward. In the vertical injection molding machine 1 according to the present embodiment, the ball screw 23 is fixed to the cross head 19. In the vertical injection molding machine 1, since the cross head 19 has a relatively small vertical movement width when the mold is opened and closed, the ball screw 23 has a small vertical movement width. Even when the ball screw 23 protrudes downward from the sleeve body 29 when the mold is opened, the lower end of the ball screw 23 does not hit the floor surface.

  The vertical injection molding machine 1 according to the present embodiment can be variously modified. For example, although the toggle mechanism 10 has been described such that the upper links 15 and 15 are shorter than the lower links 16 and 16, it does not necessarily have to be so. Even if it is equivalent length, the length of the upper links 15 and 15 may be long. In the present embodiment, the storage space 26 formed in the crosshead 19 has been described as being hollowed out in a cylindrical shape, but the shape of the storage space 26 is not limited. It is sufficient that a space is formed so that the tip of the ball nut 24 can enter when the toggle mechanism 10 is bent. In the present embodiment, the ball nut 24 is described as being provided on the lower movable platen 7 via the sleeve body 29. However, the sleeve nut 29 is not provided and the ball nut 24 is directly attached to the lower movable platen 7 by a predetermined bearing mechanism. You may make it provide.

DESCRIPTION OF SYMBOLS 1 Vertical injection molding machine 2 Clamping apparatus 3 Injection apparatus 4 Support | pillar 5 Fixed board 6 Upper movable board 7 Lower movable board 9 Tie bar 10 Toggle mechanism 12 Lower mold 13 Upper mold 15 Upper link 16 Lower link 18 Cross link 19 Crosshead 21 Pin 23 Ball Screw 24 Ball Nut 26 Storage Space 28 Spacing 29 Sleeve Body 31 Bearing Mechanism

Claims (2)

A fixed platen to which a lower mold is attached; an upper movable plate that is arranged above the fixed platen and to which an upper die is attached; a lower movable plate that is arranged below the fixed platen; and the fixed platen In a vertical injection molding machine comprising a plurality of tie bars inserted through the upper movable plate and the lower movable plate, and a toggle mechanism provided between the fixed plate and the lower movable plate,
The toggle mechanism is composed of a pair of upper links, a pair of lower links, a pair of cross links, a cross head, and a ball screw mechanism,
Each of the upper link and the lower link is pivotally supported on each of the fixed platen and the lower movable platen, and the other end is rotatably connected to each other.
The cross link has one end rotatably connected to the upper link or the lower link or both, and the other end rotatably connected to the cross head.
In the ball screw mechanism, the tip of the ball screw constituting the ball screw mechanism is fixed to the cross head, and a ball nut screwed to the ball screw is rotatably provided on the lower movable plate,
In the cross head, a fixing portion for fixing the ball screw is higher than a connecting portion connected to the cross link, and a storage space of a predetermined size is formed below the fixing portion. A vertical injection molding machine characterized in that at least the tip of the ball nut is stored in the storage space when the toggle mechanism is bent.   The vertical injection molding machine according to claim 1, wherein a cylindrical sleeve body is integrally fixed to a lower portion of the ball nut, and the sleeve body is rotatably provided on the lower movable platen. Vertical type injection molding machine characterized by

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