JP2006327131A - Mold closing device for vertical electric injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold closing device for a vertical electric injection molding machine in which the movement amount of a crosshead to a stationary platen is made to be small and the height of the device is made to be low, thereby a highly precise crosshead guide bar can be shortened. <P>SOLUTION: In the mold closing device for the vertical electric injection molding machine of this invention, a servomotor 43, an end plate 30 and a movable plate head 20 move together on the basis of a crosshead 50 between the condition of mold-opening and the condition of mold-closing, thereby the crosshead is not required to move so much and the movement amount of the crosshead in the meantime is only a small movement amount of the remainder required for the operation of a link mechanism 70. Therefore, there is very little movement amount of the cross-head and the crosshead guide bar 60 becomes short between the condition of mold-opening and the condition of mold-closing, thereby if one end is fixed to a stationary platen 10, it is enough also in strength and the length of a guide part which needs high processing precision of the crosshead guide bar can be shortened extremely. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mold clamping device for a vertical electric injection molding machine, and in particular, a movable platen is arranged above a fixed platen, and an end plate integrated with the movable platen by a tie bar is arranged below the fixed platen and fixed. A crosshead is placed between the board and the end plate, and two sets of link mechanisms consisting of three toggle links are used to make the end plate and the crosshead vertically movable within a certain range. The present invention relates to a mold clamping device for a vertical electric injection molding machine to be connected.

  FIG. 5 is a diagram showing a conventional example of a mold clamping device for a vertical electric injection molding machine, in which the left half shows a state when the mold is open and the right half shows a state when the mold is closed. This technique is disclosed in Patent Document 1 below. In this example, the link mechanism 270 includes a toggle link 271 that is rotatably attached to the lower surface of the stationary platen 210 by a link pin 275, and is rotatably attached to the end plate 230 by a link pin 277. A toggle link 272 connected to the link 271 by a link pin 276, one end is rotatably attached to the cross head 250 by a link pin 279, and the other end is rotatable to the other end of the toggle link 272 by a link pin 278. It consists of an attached toggle link 273. In this example, the ring pin 277 is provided directly below the link pin 275.

  The screw shaft 240 is arranged at an intermediate position between the two sets of toggle links 270 on the left and right sides. The upper end is supported by the stationary platen 210 (the stationary platen 210 is fixed to the machine body 201) and the lower end is supported by the machine body 201. Yes. Therefore, the screw shaft 240 is prevented from moving in the axial direction but is rotatable in the circumferential direction. The screw shaft 240 is screwed into a nut member 251 that is integrally coupled to the cross head 250. The crosshead 250 is guided by a plurality of crosshead guide bars 260 fixed so as to be perpendicular to the stationary platen 210 or the machine body 201. Therefore, when the screw shaft 240 is rotated, the crosshead 250 is moved in the vertical direction along the guide rod 260 via the nut member 251. A driven pulley 241 is attached to the lower end of the screw shaft 240 and is connected to a driving pulley of an electric motor 243 such as a servo motor by a timing belt 242. Each terminal of the tie bar 215 is fixed to the movable platen 220 and the end plate 230.

  In the above-described configuration, when the electric motor 243 is operated, the screw shaft 240 rotates, and for example, the nut member 251 is lowered together with the cross head 250. As a result, the toggle links 271 and 272 rotate inward with the link pins 275 and 277 as fulcrums to lower the end plate 230. As a result, the movable platen 220 moves downward together with the end plate 230 for clamping. When the toggle links 271 and 272 extend linearly as shown on the right side of FIG. 5, the electric motor 243 is stopped to complete the mold clamping.

When the electric motor 243 is actuated when the linear shaft is extended as shown in the right side of FIG. 5 and the screw shaft 240 is rotated in the reverse direction, the toggle links 271 and 272 are bent outward to raise the end plate 230. 220 moves upward and enters the mold open state. Therefore, the driving of the electric motor 243 is stopped, the mold opening is completed, the brake is operated, and the free rotation of the electric motor 243 is stopped.
JP 10-291239 A

  However, since the above-mentioned conventional mold clamping device for vertical electric injection molding machine has a long crosshead stroke required to bend and extend the toggle link of the link mechanism, the stationary platen, machine body, end plate, It is necessary to secure a sufficient space between them. Further, it is necessary to provide a plate connected to the machine body 201 under the end plate in order to fix the power transmission mechanism including the electric motor and the guide rod for guiding the vertical movement of the crosshead having a long stroke. These things increase the height of the machine. In addition, the crosshead guide rod must be supported at both ends, and the portion that needs to be given high surface processing accuracy is lengthened and the cost is increased.

  The present invention has been made to solve the above-described problems, and can reduce the amount of movement of the crosshead relative to the stationary platen and the machine body, thereby reducing the overall height. For the vertical electric injection molding machine that can shorten the overall length by fixing the crosshead guide rod to the fixed plate and can extremely shorten the length of the crosshead guide rod that requires high machining accuracy An object is to provide a mold clamping device.

  In order to solve the above-described problems, the mold clamping device for a vertical electric injection molding machine according to the present invention has a movable plate placed above the fixed platen, and an end integrated with the movable plate by a tie bar below the fixed plate. Place the plate, place the cross head between the fixed platen and the end plate, and use two sets of link mechanisms composed of 3 toggle links, and move the end plate and cross head up and down within a certain range A mold clamping device for a vertical electric injection molding machine that is movably connected to a fixed platen, the upper end of which is fixed to the fixed platen, and a crosshead guide rod that guides the crosshead so as to move up and down, and a fixed to the crosshead. A screw shaft that is screwed to the nut and has a lower end portion rotatably attached to the end plate at the end plate, and a drive source that is fixed to the end plate and that rotates the screw shaft about the axis. Having.

  The mold clamping device for a vertical electric injection molding machine according to the present invention has a movable plate placed above the fixed platen, an end plate integrated with the movable plate by a tie bar below the fixed plate, and the fixed platen A crosshead is placed between the end plate and the end plate, and two sets of link mechanisms consisting of three toggle links are used to connect the end plate and the cross head to the fixed plate so that they can move up and down within a certain range. A clamping device for a vertical electric injection molding machine that has a top end fixed to a stationary platen, a crosshead guide rod that guides the crosshead so that it can move up and down, and a top end that is fixed to the crosshead and rotates to the end plate A screw shaft that is screwed onto a nut that is attached to the nut and a drive source that is fixed to the end plate and that rotates the nut around the axis of the screw shaft.

  According to such a configuration, the drive source, the end plate, and the movable platen move together with respect to the crosshead between the mold open state and the mold closed state. The amount of movement is only the remaining small amount of movement necessary for the operation of the link mechanism. Therefore, the amount of movement of the crosshead is extremely small, the crosshead guide rod is shortened, and if one end is fixed to the fixed plate, it is sufficient in strength, and the guide portion that requires high processing accuracy of the crosshead guide rod is required. It is also possible to make the length extremely short.

  In the present invention, the screw shaft and the nut are preferably a ball screw and a ball screw nut.

  As described in detail above, according to the present invention, the drive source, the end plate, and the movable platen move together with respect to the crosshead between the mold open state and the mold closed state. During this time, the amount of movement of the cross head is only the remaining small amount of movement necessary for the operation of the link mechanism. Therefore, the amount of movement of the crosshead is extremely small, the crosshead guide rod is shortened, and if one end is fixed to the fixed plate, it is sufficient in strength, and the guide portion that requires high processing accuracy of the crosshead guide rod is required. The length can be made extremely short. As a result, the height of the mold clamping device for the vertical electric injection molding machine can be lowered and costs can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a front view showing a first embodiment of a mold clamping device for a vertical electric injection molding machine according to the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. It is the side view seen from the direction of arrow B, and the left half shows the state when the mold is closed and the right half shows the state when the mold is opened. In this example, the fixed platen 10 is fixed to the machine body. A movable platen 20 is disposed above the fixed platen 10, and an end plate 30 is disposed below the fixed platen 10. The movable platen 20 and the end plate 30 are integrally connected by tie bar nuts 17 at both ends of the tie bar 15 so that the movable platen 20 and the end plate 30 can move up and down while being parallel to the fixed platen 10. In this case, along the virtual center line CL, one mold 11 (for example, the lower mold) is disposed above the fixed platen 10 and the other mold 21 (for example, the upper mold) is disposed below the movable platen 20. ) Can be mounted so that they face each other.

  A bearing mechanism 31 is provided at a portion where the center line CL of the end plate 30 passes. The screw shaft 40 arranged along the center line CL is screwed into a nut 51 (see FIG. 3) attached to the cross head 50. The lower end portion of the screw shaft 40 is supported by the bearing mechanism 31 so as to be rotatable around the axis. A driven pulley 41 is fixed to the lowermost end portion of the screw shaft 40, and the driven pulley 41 is rotationally driven by a servo motor 43 via a timing belt 42. The servo motor 43 is connected to the end plate 30 so as to move together with the end plate 30. The above-described crosshead 50 is guided by a crosshead guide rod 60 whose upper end is fixed to the fixed platen 10 so as to be able to move up and down while being parallel to the fixed platen 10. In this case, the crosshead guide rod 60 passes through a bush 52 attached to the crosshead 50, as shown in FIG.

  The stationary platen 10, the end plate 30, and the cross head 50 are connected by two sets of link mechanisms 70 as shown in FIG. The link mechanism includes long toggle links 71 and 72 and a short toggle link 73 and link pins 75, 76, 77, and 78 for connecting them. One end of the toggle link 71 is rotatably attached to the protruding portion on the lower surface of the fixed platen 10 by a link pin 75. One end of the toggle link 72 is rotatably attached to a protruding portion on the upper surface of the end plate 30 by a link pin 76. One end of the toggle link 73 is rotatably attached to the cross head 50 by a link pin 77. The other ends of the toggle links 71, 72, and 73 are rotatably coupled by a link pin 78.

  Since it is configured in this way, the driven pulley in the direction in which the servomotor 43 enters the nut 51 via the timing belt 42 when the mold is closed as shown in the left half of FIG. When 41 is rotated, the link mechanism 70 begins to bend inward to reduce the distance between the end plate 30 and the crosshead 50. As a result, the end plate 30 starts to rise, and the movable platen 20 connected by the tie bar 15 also starts to rise, so that the molds 11 and 21 are also opened, and finally the mold as shown in the right half of FIG. Open state.

  Contrary to the above-described operation, when the driven pulley 41 is rotated in the direction in which the screw shaft 40 comes out of the nut 51 in the mold open state as shown in the right half of FIG. In order to increase the distance to 50, the link mechanism 70 extends, and the toggle links 71 and 72 try to align in a straight line. As a result, the end plate 30 starts to descend, and the movable platen 20 connected by the tie bar 15 also begins to descend, so that the molds 11 and 21 try to close, and finally the mold as shown in the left half of FIG. Closed. The moving amount d of the cross head 50 that moves between mold closing and mold opening is very small as compared with the conventional mold clamping apparatus. The movement amount d corresponds to a change in the distance between the link pins 75 and 77 due to the swinging of the toggle links 71 and 73.

  Next, a second embodiment of the present invention will be described with reference to FIG. In this case, the upper end portion of the screw shaft 140 is fixed to the cross head 150 so as not to rotate. On the other hand, a nut 151 that rotates with the rotation of the driven pulley 141 is incorporated in the bearing mechanism 131. Therefore, when the driven pulley 141 is rotated by the servo motor, the nut 151 rotates together with the driven pulley 141. As the nut 151 rotates, the end plate 30 rises to open the molds 11 and 21, or descends to close the mold. Others are the same as those in the first embodiment (for example, illustration of the crosshead guide rod 60, the timing belt 42, and the servomotor 43 is omitted). The amount of movement f of the cross head 150 that moves between mold closing and mold opening is very small as compared with the conventional mold clamping apparatus as in the first embodiment.

  As is clear from the above-described two embodiments, the amount of movement of the crosshead 50 that moves between mold closing and mold opening is very small compared to the conventional mold clamping device. In addition, since the link mechanism 70 is bent inward, the whole can be reduced in size. Furthermore, since the amount of movement of the crosshead 50 that moves between mold closing and mold opening is very small compared to the conventional mold clamping device, the above-mentioned crosshead guide rod 60 may be short or short. Therefore, the strength is maintained only by fixing to the fixed platen 10. Further, since the amount of movement of the crosshead is small, the surface processed portion that requires good accuracy of the crosshead guide rod 60 can be extremely shortened, and the cost can be reduced.

It is a front view which shows Embodiment 1 of the mold clamping apparatus for vertical type electric injection molding machines of this invention. It is sectional drawing seen from the line AA of FIG. It is the side view seen from the direction of the arrow B of FIG. 1, Comprising: The left half has shown the state of mold closing, and the right half has shown the state of mold opening. It is a front view which shows Embodiment 2 of the mold clamping apparatus for vertical type electric injection molding machines of this invention. It is a figure which shows the prior art example of the mold-clamping apparatus for vertical type electric injection molding machines.

Explanation of symbols

10 Fixed platen, 11, 21 Mold, 15 Tie bar, 17 Tie bar nut, 20 Movable platen, 30 End plate, 31, 131 Bearing mechanism, 40, 140 Screw shaft, 41, 141 Drive pulley, 42 Timing belt, 43 Servo motor 50,150 Crosshead, 51,151 Nut, 52 Bush, 60 Crosshead guide rod, 70 Link mechanism, 71,72,73 Toggle link, 75,76,77,78 Link pin.

Claims (3)

The movable platen (20) is arranged above the fixed platen (10), and the end plate (30) integrated with the movable platen (20) by the tie bar (15) is arranged below the fixed platen (10) and fixed. The crosshead (50) is disposed between the board (10) and the end plate (30), and two sets of link mechanisms (70) configured by three toggle links (71, 72, 73) are used. A mold clamping device for a vertical electric injection molding machine that connects an end plate (30) and a cross head (50) to a stationary platen (10) so as to be movable up and down within a certain range,
A crosshead guide rod (60) whose upper end is fixed to the stationary platen (10) and guides the crosshead (50) so as to be movable up and down;
A screw shaft (40) screwed with a nut (51) fixed to the crosshead (50) and having a lower end portion rotatably attached to the end plate (30) around an axis;
A mold clamping device for a vertical electric injection molding machine, which is fixed to the end plate (30) and has a drive source (42, 43) for rotationally driving the screw shaft (40) around the axis. The movable platen (20) is arranged above the fixed platen (10), and the end plate (30) integrated with the movable platen (20) by the tie bar (15) is arranged below the fixed platen (10) and fixed. The crosshead (150) is disposed between the board (10) and the end plate (30), and two sets of link mechanisms (70) each including three toggle links (71, 72, 73) are used. A vertical clamping apparatus for a vertical electric injection molding machine that connects an end plate (30) and a cross head (150) to a stationary platen (10) so as to be movable up and down within a certain range,
A crosshead guide rod (60) whose upper end is fixed to the stationary platen (10) and guides the crosshead so as to move up and down;
A screw shaft (140) having an upper end fixed to the crosshead (150) and screwed to a nut (151) rotatably attached to the end plate (30);
A mold clamping device for a vertical electric injection molding machine, which is fixed to the end plate (30) and has a drive source (42, 43) for rotating the nut (151) around the axis of the screw shaft (140).   The vertical screw injection molding machine clamping device according to claim 1 or 2, wherein the screw shaft and the nut are a ball screw and a ball screw nut.

Images