JP2006326893A - Mold clamping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold clamping device having a simple structure, capable of almost uniformizing the distribution of the load applied to a mold at the time of mold clamping, capable of equally applying pressure to the whole area of the mold and capable of stabilizing the dimensional precision of a molded product. <P>SOLUTION: A fixed mold 19 is attached to a fixed template 13 through a sub-plate 17 and a load receiving plate 18. The sub-plate 17 is formed into a shape larger than the mold 19 but smaller than the fixed template 13. The load receiving plate 18 is a circular plate with an appropriate thickness of which the center coincides with that of the fixed template 13 and which has a shape positioned within the attaching surface of the mold 19 and forms a gap G between the fixed template 13 and the sub-plate 17. When a movable mold 16 is pressed to the fixed mold 17 by mold clamping, pressing force is applied to the fixed template 13 and the load due to the reaction force thereof is added to the fixed mold 19. At this time, since the distribution of this load depends on the load receiving plate 18 being the circular plate, it becomes uniform in a radial direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mold clamping device such as an injection molding machine. Even when a fixed side mold plate is pressed at the time of mold clamping to cause bending, the fixed side mold is not affected by the bending, and the movable side mold It is related with the mold-clamping apparatus which enabled it to maintain the load distribution between them substantially uniformly.

  The mold clamping device of the injection molding machine moves the movable mold forward and backward with respect to the fixed mold, maintains the mold closed when the molding raw material is injected, and removes the molded product when taking out the molded product. A mechanism is provided in which the mold is separated and the mold is opened.

  By the way, in order for the molding raw material to be reliably filled in the mold at the time of molding, it is necessary to maintain an appropriate temperature when being supplied. Therefore, the mold is provided with a temperature adjusting device, and the molding raw material is provided. Is maintained at an appropriate temperature. The temperature applied to the mold is also transmitted to the fixed side mold plate and the movable side mold plate. Moreover, in order to keep the molding raw material at a predetermined temperature, the mold is maintained at a temperature higher than the temperature of the molding material, and this heat is transmitted to the fixed side mold plate and the movable side mold plate. The plate expands.

  Further, in the mold clamping device, a pressing force is applied from the movable mold to the fixed mold during mold clamping, so this pressing force is also applied to the fixed mold and the fixed mold is bent. There is a fear. When the fixed-side mold plate is bent, the bending affects the fixed-side mold and the alignment accuracy when the mold is closed is lowered, and the alignment position of the mold may be shifted. If the alignment position of the mold is shifted, the processing accuracy of the molded product may be reduced.

  Therefore, the applicant of the present application may reduce the alignment accuracy of the mold when the mold is closed even when the upper and lower mold plates are deformed by heat from the mold or the mold plates are deformed due to secular change. A mold clamping device was proposed (Patent Document 1).

  This mold clamping device is a mold clamping device that opens and closes a mold attached to each of these mold plates by moving the movable side mold plate back and forth with respect to the fixed side mold plate. Attach the fixed mold with the intermediate plate, attach the movable mold with the sub plate to the movable mold plate, and connect the precision guide device to the sub plate. The sub plate is guided by a guide device.

  FIG. 3 shows a schematic structure of the mold clamping device 1 having the sub plate. The mold clamping device 1 is provided with a fixed-side mold plate 4 fixed to an upper portion of a main stay 3 provided upright at four corners of a gantry 2, and a movable-side mold plate 5 that can be moved up and down along the main stay 3 at an intermediate portion. Is supported. A movable mold 6 is fixed to the movable mold 5 via a movable mounting plate 6a, and a fixed mold 7 is interposed between the fixed mold 4 and a fixed plate 7a with a subplate 8 interposed therebetween. It is fixed through. A projecting portion or a projecting portion sub-plate 8 a is interposed in the center of the sub-plate 8, and a gap G is formed between the fixed-side mold plate 4 and the sub-plate 8. In addition, raising / lowering of the movable side template 5 is performed by the operation of the clamping cylinder 9.

JP 2000-190332 A

  However, in the mold clamping device described in Patent Document 1 described above, the inner shape of the gap formed between the fixed-side mold plate 4 and the sub-plate 8 is substantially rectangular as shown in FIG. The distribution position of the load due to the reaction force that the fixed mold 7 receives from the fixed mold 4 is sometimes arranged along the inner edge of the gap, as shown by the triangle in the figure. This is because, since pressure is applied to the central portion of the fixed-side template 4, the fixed-side template 4 is bent so that the central portion bulges upward as shown in FIG. This is because the force is greatly received from the peripheral portion of the fixed side template 4. That is, there is a possibility that the load becomes concentrated at the four corners of the rectangle due to non-uniformity in the radial direction from the center of the fixed-side template 4. For this reason, there exists a possibility that a pressure may not be equally applied to the mating surface of the metal molds 6 and 7.

  In such a state, particularly in a multi-cavity mold, a molded product processed at the center of the mold and a molded product processed at the end of the mold are processed at the same time. Nevertheless, the dimensions in the mold clamping direction may vary. Or even when processing a single molded product, there is a possibility that a dimensional error more than molding shrinkage may occur depending on the part, and a good product may not be obtained.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a mold clamping device that has a simple structure, can make the distribution position of a load received by a mold substantially uniform, and has no variation in the dimensions of a molded product.

  As a technical means for achieving the above object, the mold clamping apparatus according to the present invention opens and closes the mold attached to each of these mold plates by moving the movable mold plate back and forth with respect to the fixed mold plate. In the mold clamping apparatus, a gap is formed between the fixed-side mold plate and the fixed-side mounting plate to which the fixed-side mold is mounted, and the inner shape of the gap is defined as the range of the mounting surface of the fixed-side mold. It is the inside, and it was characterized by forming in the substantially circular shape centering on the center part of the fixed side metal mold | die.

  When the movable side mold is pressed against the fixed side mold, a pressing force is transmitted from the circular portion to the fixed side mold plate inside the gap, and the reaction force is applied to the fixed side mold. Since the position of the load due to the reaction force is distributed in a circular shape, it is not a biased position as in the case of a rectangular shape, and can be made almost uniform in the radial direction.

  According to a second aspect of the present invention, there is provided the mold clamping device according to the first aspect of the present invention, wherein the fixed-side mold plate has a surface on the fixed-side mold side centered on a central portion of the fixed-side mold, The gap is formed by forming a substantially circular projecting receiving portion located within the range.

  In order to form the inner shape of the gap in a circular shape, a circular protrusion receiving portion is formed on the stationary side template, and the protrusion amount of the protrusion receiving portion becomes the size of the gap.

  According to a third aspect of the present invention, there is provided the mold clamping device according to the first aspect of the present invention, wherein the fixed-side mold is attached to the fixed-side mold centered on the fixed-side mold plate-side surface of the fixed-side mold. The gap is formed by forming a substantially circular projecting receiving portion located within the range.

  In order to form the inner shape of the gap in a circular shape, a circular protruding receiving portion is formed on the fixed mold, and the protruding amount of the protruding receiving portion becomes the size of the gap.

  According to a fourth aspect of the present invention, there is provided a mold clamping device having a substantially circular shape centered on a central portion of the fixed side mold plate between the fixed side mold plate and the fixed side mounting plate. It is characterized in that a load receiving plate having an appropriate thickness located within the range of the mounting surface is interposed.

  In order to form the inner shape of the gap in a circular shape, a structure in which a circular protrusion receiving portion is formed on the fixed side mold plate or the fixed side mold as described above may be used. However, even if a circular load receiving plate is interposed instead of the protruding receiving portion, the inner shape of the gap can be made circular.

  Further, in the mold clamping device according to the invention of claim 5, a sub plate is interposed between the fixed side mold plate and the fixed side mounting plate, and the gap is formed between the fixed side mold plate and the sub plate. It is characterized by.

  The gap is formed between the sub-plate and the fixed-side template. In order to form the inner shape of the gap in a circular shape, the sub-plate can be provided with a circular protruding receiving portion, and the protruding receiving portion can be brought into contact with the fixed side template, It is also possible to adopt a structure in which the load receiving plate is interposed between the sub plate and the stationary side plate.

  According to the mold clamping device of the present invention, during clamping, since a reaction force is applied to the stationary mold by receiving a pressing force on the stationary mold plate with a circular surface, a load is applied to the stationary mold. Is applied almost uniformly without bias. For this reason, the alignment precision of a metal mold | die is substantially equalized in the metal mold | die surface, and the dimensional accuracy of a molded product can be maintained as desired. In particular, when molding is performed with a large number of pieces, it is possible to eliminate dimensional errors in the mold clamping direction of molded products processed at the same time, and to prevent the occurrence of defective products as much as possible.

  In addition, according to the mold clamping device according to the invention of claim 2 or claim 3, the protruding receiving portion can be formed when the fixed side mold plate or the fixed side mold is manufactured. Further, since the positioning and the like of the protrusion receiving portion is completed by attaching the mold, the attaching operation is not complicated.

  According to the mold clamping device of the fourth aspect of the present invention, since the portion that deteriorates due to wear due to repeated mold clamping and mold opening becomes the load receiving plate, it is possible to prevent the mold from deteriorating.

  Further, according to the mold clamping device according to the invention of claim 5, since the sub-plate is interposed, the load applied to the mold can be made uniform by slightly improving the existing mold clamping device. it can.

  Hereinafter, a mold clamping device according to the present invention will be described in detail based on the illustrated preferred embodiment. FIG. 1 shows a schematic structure of the mold clamping device 10. A main stay 12 erected at four corners of a gantry 11 is attached, and a fixed-side mold plate 13 is fixed to the upper part thereof. A movable side template 14 is supported at the intermediate portion so as to be movable up and down along the main stay 12. The movable side mold plate 14 is moved up and down by a mold clamping cylinder 15. A movable mold 16 is attached to the movable mold 14 via a movable mounting plate 16a.

  A fixed side mounting plate 19a is attached to the fixed side mold plate 13 with a sub plate 17 and a load receiving plate 18 interposed therebetween, and a fixed side mold 19 is attached to the fixed side mounting plate 19a. As shown in FIG. 2, the load receiving plate 18 is a circular plate centered on the central portion of the fixed mold 19 and has an appropriate thickness, and is within the range of the mounting surface of the fixed mold 19. It is located. Further, the sub plate 17 is larger than the fixed side mold 19 and smaller than the fixed side mold plate 13, and the load receiving plate 18 is interposed between the fixed side mold plate 13 and the sub plate 17. A gap G is formed.

  The operation of the mold clamping apparatus 10 according to the embodiment of the present invention configured as described above will be described below.

  FIG. 1 shows a state at the time of mold clamping, in which the mold clamping cylinder 15 raises the movable side mold plate 14 and presses the movable side mold 16 against the fixed side mold 19. In this state, a molding material is injected from a not-shown injection apparatus into a mold to process a desired molded product. In a state where the movable mold 16 is pressed against the fixed mold 19, the pressing force is applied to the fixed mold 13 via the sub plate 17 and the load receiving plate 18. Then, the reaction force is applied to the fixed mold 19, and the load at that time is applied via the disk-shaped load receiving plate 18, and the distribution is shown by the upper triangle in FIG. In addition, it becomes a circular range. For this reason, it becomes substantially uniform in the radial direction around the center of the fixed-side template 13. Therefore, an unbalanced load is not applied to the fixed-side mold 19, and a substantially uniform pressure is applied to the mold when the mold is clamped. For this reason, even in the case of a multi-cavity mold, an error does not occur in a molded product processed at the same time, and stable molding can be performed with high accuracy.

  The mold opening is performed by operating the main cylinder 15 and lowering the movable side mold plate 14.

  In the embodiment described above, the sub plate 17 and the load receiving plate 18 are described as separate bodies. However, if the gap G is formed between the fixed side mold plate 13 and the sub plate 17, the load receiving plate 18 and the load receiving plate 18 are separated. A structure in which a corresponding portion of the plate 18 is formed so as to protrude from the sub-plate 17 may be employed.

  Further, although the description has been given as the structure in which the sub-plate 17 is interposed, a protruding receiving portion corresponding to the load receiving plate 18 is formed on the fixed side mounting plate 19a, and the fixed side mounting plate 19a is fixed between the fixed side mounting plate 19a and the fixed side mounting plate 19a. It is also possible to adopt a structure in which the gap G is formed in the gap. Alternatively, the same is true if a protrusion receiving portion corresponding to the load receiving plate 18 is formed on the surface of the fixed side mold plate 13 on the mold side.

  The mold clamping device according to the present invention can substantially uniform the load distribution applied to the mold. For example, in the case of a multi-cavity mold, the mold is clamped over the entire area of the mold. Since pressure can be applied evenly, the dimensional accuracy can be made constant regardless of the molding position in the mold, and the occurrence of defective products can be eliminated. Further, in the case of a single molded product, it can be molded with stable dimensional accuracy.

It is a front view showing a schematic structure of a mold clamping device concerning this invention. It is a schematic plan view of the mold clamping apparatus shown in FIG. It is a front view which shows schematic structure of the conventional mold clamping apparatus. FIG. 4 is a schematic plan view of the conventional mold clamping device shown in FIG. 3.

Explanation of symbols

G gap
10 Clamping device
11 frame
12 Main stay
13 Fixed side template
14 Movable side template
15 Clamping cylinder
16 Movable mold
17 Sub-plate
18 Load receiving plate
19 Fixed mold
19a Fixed side mounting plate

Claims (5)

In the mold clamping device that opens and closes the mold attached to each of these mold plates by moving the movable mold plate back and forth with respect to the fixed mold plate,
Forming a gap between the fixed side mold plate and the fixed side mounting plate to which the fixed side mold is mounted;
A mold clamping device, wherein an inner shape of the gap is formed in a substantially circular shape within a range of a mounting surface of the fixed side mold and centering on a central portion of the fixed side mold.   A substantially circular projecting receiving portion is formed on the surface of the stationary mold plate on the stationary mold side, centered on the central portion of the stationary mold, and located within the range of the mounting surface of the stationary mold. The mold clamping device according to claim 1, wherein the gap is formed.   A substantially circular projecting receiving portion is formed on the surface of the stationary mold on the stationary mold plate side, centered on the central portion of the stationary mold and positioned within the range of the mounting surface of the stationary mold. The mold clamping device according to claim 1, wherein the gap is formed.   Between the fixed side mold plate and the fixed side mounting plate, a substantially circular load centered on the central portion of the fixed side mold plate and having an appropriate thickness located within the range of the fixed side mold mounting surface 2. The mold clamping apparatus according to claim 1, wherein a receiving plate is interposed. A sub-plate is interposed between the fixed side mold plate and the fixed side mounting plate,
The mold clamping device according to claim 1, wherein the gap is formed between the fixed-side mold plate and the sub-plate.

Images