JP2013000774A - Clamping device of injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress flashes and an increase in thickness of a molded product without enlarging a mold.SOLUTION: The clamping device includes a first attaching part 15 to which a stationary mold 5 is attached, a second attaching part 16 to which a movable mold 4 is attached, a stationary platen 9 disposed on the opposite side of the second attaching part in relation to the first attaching part, at least one movable block 12 disposed between the first attaching part and the stationary platen, and a driving mechanism 11 making the movable block movable and fixing the movable block at a predetermined position. The second attaching part 16 is movable relative to the first attaching part 15 for abutting/separating the movable mold on/from the stationary mold. The movable block 12 is in contact with both of one surface 17 on the first attaching part side and one surface 18 on the stationary platen side which is inclined relative to the one surface 17. The driving mechanism 11 makes the movable block 12 slide-movable for adjusting a distance from the one surface 18 on the stationary platen side to the one surface 17 on the first attaching part side.

Description

  The present invention relates to a mold clamping device used in an injection molding machine.

  2. Description of the Related Art A metal injection molding machine that performs injection molding of a metal material includes a mold clamping device that clamps a mold for molding the metal material (see Patent Document 1). A conventional metal injection molding machine equipped with such a mold clamping device will be described with reference to FIG.

  As shown in FIG. 3, the injection molding machine includes an injection device that injects a raw material, molds 4 and 5 that mold the raw material into a predetermined shape, a mold clamping device that clamps the molds 4 and 5, It has.

  The injection device includes a heater 1, a cylinder 2 and a screw 3. The cylinder 2 is heated by the heater 1, and the raw material is put into the cylinder 2 from the right side of FIG. As the screw 3 in the cylinder 2 moves backward while rotating, the charged raw material is conveyed to the front of the cylinder 2. Then, the raw material is heated by the heater 1 through the cylinder 2 to be in a molten state and stored in front of the screw 3.

  The mold clamping device includes a stationary platen 9 to which the stationary die 5 is fixed, and a movable platen 13 that holds the movable die 4 so as to be movable with respect to the stationary die 5. When the movable platen 13 is moved to close the mold together with the movable mold 4 and the fixed mold 5, the cavity 8 is formed in the mold. In this state, the cylinder 2 moves forward, and the nozzle 6 provided in front of the cylinder 2 is brought into contact with the sprue 7 formed on the mold. The nozzle 6 and the mold are pressed at a high pressure so that the molten material does not leak, and the screw 3 is moved at a high speed, so that the molten material passes through the runner from the sprue 7 serving as a gate through the nozzle 6. Then, the cavity 8 is filled.

  The molten raw material filled in the cavity 8 is cooled and solidified in the mold. Thereafter, the movable mold 4 is moved to open the mold, and the molded product is removed from the mold. The product after molding is released by ejecting a molded product by an ejector pin (not shown) connected to an ejector plate (not shown).

JP 2010-247385 A

  The molten raw material filled in the cavity at a high temperature and high pressure has high energy and places a high load on the mold for receiving the molten raw material. Recently, the demand for thin and light molded products is high, and the injection speed of raw materials from the injection apparatus is increasing. For this reason, a higher load is applied to the mold, for example, the temperature of the mold rises or the pressure applied to the mold increases. As a result, it has become difficult to make the molded product into a predetermined shape due to insufficient rigidity of the mold.

  Specifically, as shown in FIGS. 4A and 4B, the thickness of the molded product 32 may become thicker than the required design value due to insufficient clamping force. Further, burrs may occur in the molded product depending on the rigidity, thickness, material, etc. of the mold.

  To increase the rigidity of the mold, it is conceivable to increase the size of the mold. However, due to the increase in size of the mold, it is necessary to change the design of the mold.

  In order to solve such a problem, an object of the present invention is to provide a mold clamping device that can suppress an increase in burrs and thickness of a molded product without increasing the size of a mold.

  In order to achieve the above object, a mold clamping device according to the present invention includes a first attachment portion to which a fixed mold can be attached, a second attachment portion to which a movable die can be attached, and a first attachment portion. 2, a fixed plate provided on the opposite side of the mounting portion, at least one movable block provided between the first mounting portion and the fixed plate, the movable block being movable, and the movable block being a predetermined block And a drive mechanism fixed at the position. The second mounting portion is movable with respect to the first mounting portion so that the movable mold is brought into contact with and separated from the fixed mold. The movable block is in contact with both one surface of the first mounting portion side and one surface of the fixed platen side inclined with respect to the one surface. The drive mechanism allows the movable block to slide so that the distance from one surface on the fixed platen side to one surface on the first mounting portion side can be adjusted.

  According to the mold clamping device of the present invention, the mold clamping force of the mold is arbitrarily adjusted by moving the movable block between the stationary platen and the first mounting portion and pressing the stationary platen with the movable block. can do. Thereby, the burr | flash of a molded product, the increase in thickness, etc. can be suppressed, without enlarging a metal mold | die for the rigidity increase of a metal mold | die.

It is sectional drawing which shows the injection molding machine provided with the mold clamping apparatus of this invention. (A) is a perspective view of the molded product shape | molded using the injection molding machine shown in FIG. 1, (b) is sectional drawing along the 2B-2B line | wire of (a). It is sectional drawing which shows the injection molding machine provided with the conventional mold clamping apparatus. (A) is a perspective view of a molded product when the mold clamping force of the mold is insufficient, and (b) is a cross-sectional view taken along line 4B-4B of (a).

  Hereinafter, an injection molding machine including a mold clamping device according to an embodiment of the present invention will be described. The present invention can be applied to all mold clamping devices for clamping a mold used in injection molding. Various materials such as a magnesium alloy or a zinc alloy can be used as the raw material to be injected.

  FIG. 1 shows an injection molding machine provided with a mold clamping device of the present invention. The mold clamping device includes an injection device that injects a raw material, and a mold clamping device that molds the movable mold 4 and the fixed mold 5. The configuration of the injection device is the same as that of the injection device shown in FIG.

  The mold clamping device includes a first attachment portion 15 to which the fixed mold 5 can be attached, and a second attachment portion 16 to which the movable die 4 can be attached. The fixed mold 5 and the movable mold 4 are attached to these attachment portions 15 and 16 so as to face each other.

  The second attachment portion 16 is movable with respect to the first attachment portion 15 so that the movable die 4 is brought into contact with and separated from the fixed die 5 attached to the first attachment portion 15. It is configured. In the example shown in FIG. 1, the second mounting portion 16 is fixed to a movable plate 19 configured to be movable by a moving mechanism 20. A fixed platen 9 is provided on the opposite side of the second mounting portion 16 with respect to the first mounting portion 15. The stationary platen 9 is firmly fixed to the mold clamping device body.

  The fixed platen 9 and the movable platen 19 are held by the same rail 14, and the movable platen 19 is configured to be movable along the rail 14. When the movable platen 19 is moved to close the mold together with the movable mold 4 and the fixed mold 5, the cavity 8 is formed in the mold.

  At least one movable block 12 is provided between the first mounting portion 15 and the fixed platen 9. The movable block 12 has a tapered shape in contact with both the one surface 17 on the first mounting portion side and the one surface 18 on the fixed platen side inclined with respect to the one surface 17.

  Further, the mold clamping device allows the movable block 12 to slide so that the distance from the one surface 18 on the fixed platen side to the one surface 17 on the first mounting portion side can be adjusted, and the movable block 12 is moved at a predetermined position. It has the drive mechanism 11 to fix. As such a drive mechanism 11, a cylinder, a screw, or a ball screw can be used.

  In the mold clamping device having the above configuration, the opening amount of the mold can be adjusted by arbitrarily adjusting the distance from the one surface 18 on the fixed platen side to the one surface 17 on the first mounting portion side by the movable block 12. it can. Since the mold clamping force of the mold can be arbitrarily adjusted by pressing the first mounting portion 15 with the movable block 12, the thickness variation of the molded product can be reduced, and the molded product with high dimensional accuracy. Can be formed. In particular, if the movable block 12 has an acute taper portion as shown in FIG. 1, the movable block 12 is inserted between the one surface 18 on the fixed platen side and the one surface 17 on the first mounting portion side. A strong clamping force can be applied to the mold. In this way, it is possible to prevent the mold from opening at the time of injection, and to prevent unexpectedly an increase in the thickness of the molded product or occurrence of burrs.

  In the mold clamping device having the above-described configuration, since the rigidity of the mold can be increased by the movable block 12, it is not necessary to increase the size of the mold. Further, since the movable block 12 is provided between the first mounting portion 15 to which the fixed mold 5 is mounted and the fixed platen 9, the movable block 12 does not affect the mold design. Thereby, the mold design is easy, and there is an advantage that the mold used in the conventional mold apparatus can be used in the mold clamping apparatus of the present invention.

  In the example shown in FIG. 1, the mounting plate 10 is fixed to the stationary platen 9. Further, the fixed block 13 is fixed to the fixed platen 9 via the mounting plate 10. The movable block 12 and the fixed block 13 are preferably made of a highly rigid member.

  In FIG. 1, one surface 18 on the fixed platen side is one surface of the fixed block 13 fixed to the fixed platen 9, and the movable block 12 is sandwiched between the fixed block 13 and the first mounting portion 15. . The first attachment portion 15 and the fixed block 13 form a pair of surfaces 17 and 18 that are inclined in a V shape. The movable block 12 is in contact with the pair of surfaces 17 and 18.

  In the example shown in FIG. 1, a fixed block 13 made of a member different from the mounting plate 10 is used to easily form a pair of surfaces 17 and 18 inclined in a V shape. However, the fixing block 13 may be a part of a member formed integrally with the mounting plate 10, that is, a part of the mounting plate 10.

  In addition to the example shown in FIG. 1, the one surface 17 on the first attachment portion side is one surface of another fixed block fixed to the first attachment portion, and the movable block is sandwiched between the fixed block and the fixed platen. It may be. That is, the movable block 12 and the fixed block 13 may be arranged in the opposite manner to the example shown in FIG. In this case, the fixed block 13 may be a part of a member formed integrally with the first attachment portion 15, that is, a part of the first attachment portion 15.

  As shown in FIG. 1, it is preferable that a plurality of movable blocks 12 are provided. Each movable block 12 is in contact with a different portion of the one surface 17 on the first attachment portion side. In the example shown in FIG. 1, two movable blocks 12 are arranged side by side in a direction perpendicular to the installation surface 21 of the injection molding machine, for example, the floor surface. A plurality of driving mechanisms 11 are preferably provided corresponding to each movable block 12. Each drive mechanism 11 moves each movable block 12 in the vertical direction of FIG.

  As described above, by using two or three or more movable blocks 12, there is an advantage that a mold clamping force having a different size can be applied to the fixed mold 5 for each place. For example, when a burr is easily formed below the molded product or the thickness of the molded product tends to increase, the cylinder or screw that is the moving mechanism 11 for the lower movable block 12 shown in FIG. Include. As a result, a large mold clamping force is applied below the fixed mold 5 to stabilize the shape of the molded product. Similarly, when a burr is easily formed above the molded product or the thickness above the molded product is likely to increase, the mold clamping force is adjusted by the upper movable block 12 in FIG. In this way, by adjusting the balance of the clamping force with respect to the vertical direction of the mold, as shown in FIGS. 2A and 2B, a molded product 30 with high dimensional accuracy can be formed. it can.

  By adjusting the balance of the mold clamping force with the plurality of movable blocks 12, there is an advantage that it is not necessary to repeatedly adjust the abutment between the movable mold 4 and the fixed mold 5. Further, since the rigidity of the mold can be locally increased for each movable block 12, the mold clamping force can be adjusted so as to obtain a stable molded product in a short time. As a result, it is possible to quickly move to a mass production system for molded products. Furthermore, since the maintenance interval of the mold can be extended during mass production, the downtime of the mold clamping device can be reduced and the production efficiency of the molded product is improved.

  Instead of the above example, the two movable blocks 12 may be arranged side by side in the horizontal direction with respect to the installation surface 21. In this case, the drive mechanism 11 moves each movable block 12 in the horizontal direction. In this case, the balance of mold clamping force can be adjusted by the plurality of movable blocks 12 in the left-right direction of the mold.

  Not only these examples, but a plurality of movable blocks should just be arranged in arbitrary places in consideration of balance of mold clamping force of a metallic mold. Further, the direction of the sliding movement of the movable block may be any direction as long as the distance from the one surface 18 on the fixed platen side to the one surface 17 on the first mounting portion side can be adjusted.

  Although the preferred embodiments of the present invention have been presented and described in detail above, the present invention is not limited to the above-described embodiments, and it is understood that various changes and modifications can be made without departing from the gist. I want to be.

4 movable mold 5 fixed mold 9 fixed plate 10 mounting plate 11 drive mechanism 12 movable block 13 fixed block 15 first mounting portion 16 second mounting portion 17 one surface on the first mounting portion 18 one surface on the fixed plate side 19 Movable platen

Claims (5)

A first attachment portion to which a fixed mold can be attached;
A second mounting portion that is attachable to a movable mold, and is movable with respect to the first mounting portion so that the movable mold is brought into contact with and separated from the fixed mold;
A stationary platen provided on the side opposite to the second mounting portion with respect to the first mounting portion;
At least one movable block provided between the first mounting portion and the fixed platen, the one surface on the first mounting portion side and the one surface on the fixed platen side inclined with respect to the one surface. A movable block in contact with both,
A drive mechanism that allows the movable block to slide so that the distance from one surface of the fixed platen side to one surface of the first mounting portion can be adjusted, and that fixes the movable block at a predetermined position; A mold clamping device of an injection molding machine. There are a plurality of the movable blocks, and each of the movable blocks is in contact with a different part of one surface of the first mounting portion side,
2. The mold clamping apparatus for an injection molding machine according to claim 1, wherein a plurality of the drive mechanisms are provided corresponding to each of the movable blocks.   The mold clamping device for an injection molding machine according to claim 1 or 2, wherein the drive mechanism is a cylinder, a screw, or a ball screw. One surface of the fixed platen is one surface of a fixed block fixed to the fixed platen,
The mold clamping device for an injection molding machine according to any one of claims 1 to 3, wherein the movable block is sandwiched between the fixed block and the first attachment portion. One surface of the first mounting portion side is one surface of a fixed block fixed to the first mounting portion,
The mold clamping device for an injection molding machine according to any one of claims 1 to 3, wherein the movable block is sandwiched between the fixed block and the fixed platen.

Images