JP4463787B2 - Molding device for injection molding machine - Google Patents

Description

The present invention relates to a mold clamping device of an injection molding machine, and more particularly to a correction plate that prevents a movable mold from being bent by a movable platen during mold clamping.

In an injection molding machine provided with a mold clamping device composed of a toggle mechanism, a toggle link is pivotally attached to the vertical position on the back of the movable platen, and a mold clamping force is applied to the vicinity of both upper and lower ends of the movable platen. Therefore, compared with a direct pressure type mold clamping device that directly pressurizes the central portion of the movable mold, there is a problem that the upper and lower sides of the movable platen bend toward the fixed platen during mold clamping. Further, the bending of the movable plate extends to the movable mold. When the side end portion and the central portion of the movable mold are compared, the clamping force does not reach the central portion, and the thickness of the molded product is not uniform. There is a problem that molding defects such as occurrence of short cuts and short shots tend to occur.

As a means for solving the above-mentioned problems, there is known a mold clamping device in which the platen of the movable plate is increased to increase the rigidity, or two movable plates are used to prevent the mold mounting surface from being bent. . In addition, as disclosed in Patent Document 1, a device in which the shape of the movable plate is devised so that the clamping force of the toggle link is directly applied to the back surface of the movable die is also known. However, in Patent Document 1, the structure of the movable plate is complicated and difficult to process, leading to an increase in cost. In addition, it is impossible to replace only the movable plate while keeping the structure of the link mechanism of the conventional injection molding machine.
JP 2003-89133 A (Claim 1, FIG. 1, FIG. 2)

In view of the above problems, the present invention solves the problem of bending of the movable plate of the mold clamping device including the toggle mechanism by a simple mechanism without complicating the structure of the movable plate, and allows the movable plate to have a movable plate. An object of the present invention is to provide a mold-clamping device in which the bending of the material hardly reaches. Moreover, it can be mounted on a movable plate of a conventional injection molding machine that does not take measures against bending of the movable plate as it is or by processing the surface facing the fixed plate, and the movable plate is almost free from bending. An object is to provide a lost mold clamping device. It is another object of the present invention to provide a mold clamping device capable of improving the parallelism even when there is a problem with the parallelism of the contact surface between the fixed mold and the movable mold.

According to a first aspect of the present invention, there is provided a mold clamping apparatus for an injection molding machine in which a movable plate with a movable die attached is moved relative to a fixed plate with a fixed die attached thereto by a toggle mechanism. In the mold clamping device of an injection molding machine, a correction plate is arranged at the center of the fixed plate facing surface of the movable plate so as to protrude from the fixed plate facing surface, either directly by a bolt or via a pressing member. with that, by another bolt is fixed to the bolt holes around the movable platen straightening plate without being inserted into the straightening plate via the through-hole without screws mold mounting plate of the movable mold, straightening A movable mold is fixedly provided on the front surface of the plate .

A mold clamping device for an injection molding machine according to claim 2 of the present invention is the fitting device according to claim 1, wherein the correction plate is a substantially circular plate-like body and is formed to be recessed one step lower than the fixed plate facing surface of the movable platen. It is characterized by being disposed in the joint recess.

According to a third aspect of the present invention, in the mold clamping device of the injection molding machine according to the first or second aspect, the protruding amount of the correction plate from the fixed plate facing surface is 0.1 mm to 5.0 mm. It is characterized by.

According to a fourth aspect of the present invention, there is provided a mold clamping device for an injection molding machine according to any one of the first to third aspects, wherein the mold contact surface when the correction plate is attached to the movable mold , The movable platen is not parallel to the fixed plate facing surface.

The injection molding machine of the present invention is an injection molding machine provided with a mold clamping device comprising a toggle mechanism. The center of the movable plate facing surface of the movable plate protrudes from the fixed plate facing surface and the correction plate is bolted. Corrected plate of movable plate without being inserted into straight plate through screwless through hole of mold mounting plate of movable mold while being arranged fixedly or directly through holding member Since the movable die is fixed to the front surface of the correction plate by being fixed to the bolt holes around the platen, it prevents the occurrence of molding defects due to the influence of the deflection of the movable plate on the movable die. can do.

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic explanatory view of an injection molding machine to which a correction plate is attached. FIG. 2 is a cross-sectional view of the movable platen, the movable mold, and the correction plate, showing a cross section taken along line AA in FIG. FIG. 3 is a front view showing the positional relationship between the movable platen, the movable mold, and the correction plate.

As shown in FIG. 1, a mold clamping device 11 of an injection molding machine is disposed on a bed 12 so as to face the injection device 13. The mold clamping device 11 includes a stationary platen 15 to which a stationary mold 14 is attached, a pressure receiving plate 16 disposed in parallel to the stationary platen 15, four tie bars 17 provided therebetween, and the tie bar A movable platen 19 and the like, which are movably disposed through 17 and to which a movable mold 18 is attached, are configured. A toggle mechanism 20 is provided between the pressure receiving plate 16 and the movable platen 19. The toggle mechanism 20 moves the cross head 27 forward and backward by a ball screw mechanism 24 including a mold clamping servomotor 21 attached to the pressure receiving plate 16, a motor side pulley, a belt, a ball screw side pulley, a ball screw 22, a ball nut 23, and the like. A drive mechanism is provided for operation.

The link mechanism 25 of the toggle mechanism 20 includes a first link 25a, one end of which is connected to the vicinity of both upper and lower ends of the back surface (on the side opposite to the fixed platen) of the movable platen 19 via a pin 26a and a bush. One end is connected to the other end via a pin 26b and a bush, and the other end is connected to the pressure receiving plate 16 via a pin 26c and a bush, on the inner side near one end of the second ring 25b. A third link 25c having one end connected through a pin 26d and a bush, and a cross head 27 to which the other end of the third link 25c is connected through a pin 26e and a bush to which the ball nut 23 is fixed. . Then, the forward / backward movement of the cross head 27 is converted into the mold opening / closing operation of the movable plate 19 and the movable mold 18 via the link mechanism 25. The first link 25a and the second link 25b are provided so that the link is extended at an angle inward (center side of the movable platen 19) with respect to the mold opening / closing direction when the mold is clamped. The mold clamping force is easily transmitted toward the center of the movable platen 19.

The upper and lower projections 28 and 28 to which the pins 26a and 26a to which the first links 25a and 25a on the back surface of the movable plate 19 are attached are connected by a connection plate 19a. Therefore, the connection plate 19a can prevent the upper and lower ends of the movable plate 19 from being bent toward the fixed plate 15 to some extent during mold clamping. A belt or pulley connected to the servo motor of the ejector device 29 is disposed on the side opposite to the fixed plate of the connection plate 19a, and in the space between the connection plate 19a and the movable plate body 19b, A ball screw mechanism and a movable ejector plate are provided. In the present embodiment, the fixed platen 15 and the movable platen 19 are manufactured by casting (cast iron), but may be manufactured by other manufacturing means.

Next, the correction plate 30 of the present embodiment for the purpose of preventing the bending of the movable platen 19 from being exerted on the movable mold 18 during mold clamping will be described. As shown in FIGS. 2 and 3, the fixed plate facing surface 19 c of the movable platen 19 is provided with a bolt hole 31 for mounting a movable die or a T groove (not shown). In addition, a fitting recess 32 is provided in the center of the movable platen 19 so as to be lower and rounder than the fixed plate facing surface 19c. In the present embodiment, the correction plate 30 is attached to the central portion of the movable platen 19. However, a possible example includes the case where the correction plate is attached at a position that is about several centimeters away from the center of the movable plate, such as when the cavity of the mold is off the center. Accordingly, the correction plate 30 is attached to a substantially central portion of the movable platen 19 in a broad sense. The correction plate mounting surface 32a of the fitting recess 32 is provided in parallel with the fixed plate facing surface 19c, and a protrusion rod 33 of the ejector device 29 is provided at the center of the correction plate mounting surface 32a and its periphery. Are provided with ejector holes 34 and correction plate mounting bolt holes (screw holes) 35. In the present embodiment, in addition to the ejector hole 34 in the central portion, the hole 34 provided in the periphery and the bolt holes 35 for attaching the correction plate are both provided at four locations.

The correction plate 30 is a substantially circular plate-like body having a constant thickness fitted in the fitting recess 32, and the movable plate contact surface 30a and the mold contact surface 30b that are in contact with the movable plate 19 are It is provided in parallel. The correction plate 30 is selected from hot rolled steel having a higher yield point than the movable platen 19 manufactured by casting. And in this embodiment, although the correction plate 30 consists of SS400 steel, you may make it form with other high-tensile steel and steel materials with much carbon content. Further, the correction plate 30 is not necessarily circular, and may be a rectangular plate or a rectangular corner portion formed in an arc shape like the shape of the mold body 18a viewed from the fixed platen 15 side.

The correction plate 30 is provided with an ejector through hole 41 at the same position as the ejector hole 34 of the movable platen 19. Further, the correction plate 30 is provided with a through hole (without screw) 37 through which the mounting hexagon socket head bolt 36 is inserted at the same position as the correction plate mounting bolt hole 35 on the correction plate mounting surface 32a. . A concave step portion 38 is provided around the through hole 37 of the mold contact surface 30b of the correction plate 30 to lock the hexagon socket head bolt 36 without protruding from the mold contact surface 30b. ing. Therefore, the correction plate 30 is fixed to the bolt hole 35 for mounting the correction plate of the fitting recess 32 provided in the movable plate 19 through the through hole 37 by the hexagon socket head bolt 36. In the present embodiment, when the correction plate 30 is attached to the movable platen 19, the correction plate 30 is provided so as to protrude 0.3 mm from the fixed plate facing surface 19c. The protrusion amount is appropriately 0.1 mm to 5.0 mm, more preferably 0.2 mm to 1.0 mm, although it depends on the size of the movable platen 19. In this embodiment, the correction plate 30 is attached to the fitting recess 32 provided on the fixed plate facing surface 19c (die mounting surface) of the movable plate 19, but directly on the fixed plate facing surface formed of an unprocessed plane. A correction plate may be attached. Furthermore, a correction plate may be integrally provided from the beginning by casting or the like at substantially the center of the surface of the movable platen that faces the fixed platen. In those cases, the correction plate having a thickness of up to about 5.0 mm is used. Further, a plate body larger than the area of the correction plate may be fixed on the mold contact surface of the correction plate, and the plate body and the mold mounting plate of the movable mold may be fixed.

As is well known, the movable mold 18 includes a mold body 18a indicated by a two-dot chain line in FIG. 3 and a mold attachment plate 18b similarly indicated by a one-dot chain line. A through hole (no screw) 39 is provided in the mold mounting plate 18 b so as to coincide with the bolt hole 31 for mounting the movable mold provided in the movable platen 19. Note that, depending on the mold, a mold mounting plate is not provided with a through hole, and a mold mounting claw member and a mounting bolt are used together to mount the mold on the movable plate. Further, a through hole 18c is provided on the back side of the movable mold 18 for insertion of the ejector rod so that a molded product can be projected from the cavity surface 18d. As shown in FIG. 3, the relationship between the correction plate 30 and the movable mold 18 in the present embodiment is such that the diameter of the correction plate 30 and the length of one side of the mold mounting plate 18b of the movable mold 18 are substantially the same. ing. The vicinity of the four corners of the mold mounting plate 18b is fixed directly to the movable mold mounting bolt hole 31 provided on the fixed plate facing surface 19c of the movable plate 19 without using the correction plate 30 by the mounting bolt 40. It is like that. Further, the mold body 18 a is provided so as not to protrude from the correction plate 30 when the mold body 18 a is viewed from the fixed platen 15 side. However, this embodiment shown in FIG. 3 is merely an example, and depending on the movable mold to be attached, the outer periphery of the mold mounting plate and the mold main body may protrude from the outer periphery of the correction plate, Alternatively, the outer periphery of the mold mounting plate may be smaller than the outer periphery of the correction plate. Anyway, what is necessary is just to be able to fix the mold mounting plate to the movable platen without using the correction plate attached to the movable platen. The correction plate is generally attached to a movable platen, but the correction plate may be fixed first on the mold attachment plate side of the movable mold.

Next, the operation of the mold clamping device 11 of the injection molding machine in which the movable mold 18 is attached to the movable plate 19 via the correction plate 30 will be described. The mold clamping servomotor 21 operates the toggle mechanism 20 including the ball screw mechanism 24, the cross head 27, the link mechanism 25, and the like, and the movable platen 19 is moved in the mold closing direction. The fixed mold 14 disposed on the fixed platen 15 and the movable mold 18 disposed on the movable platen 19 are brought into contact with each other. However, the crosshead 27 is moved forward by the driving force of the servo motor 21 and the link is moved. The links 25a and 25b of the mechanism 25 are displaced in a direction that extends in a single line. At the same time, the tie bar 17 is extended and the pressure receiving plate 16 is retracted, and a clamping force is exerted between the fixed mold 14 and the movable mold 18. At this time, since the upper and lower links 25a and 25a are attached to the protrusions 28 near the upper and lower ends of the movable platen 19, the force by the link mechanism 25 is movable via the vicinity of the upper and lower ends of the movable platen 19 It is transmitted to the mold 18. As a result, the vicinity of the upper and lower ends of the movable platen 19 is slightly deformed so as to bend toward the fixed platen 15. The amount of deformation at this time varies depending on the size of the injection molding machine, the vertical length of the movable platen, and the clamping force, but both sides of the movable platen 19 are about 0.05 mm to 0.1 mm. Deform.

However, in the present embodiment, the portion of the bolt hole 31 for mounting the movable mold provided in a relatively close portion of the movable platen 19 is deformed (displaced) toward the fixed platen due to the bending of the movable platen 19. Even so, the deformation (displacement) is hardly exerted on the movable mold 18. This is because the mold mounting plate 18b of the movable mold 18 is only inserted through the mounting bolt 40 through the screw-free through hole 39, so that the mounting bolt 40 and the mold mounting plate 18b are slidable. Even if the mounting bolt 40 moves slightly toward the fixed platen, the mold mounting plate 18b does not bend the movable platen 19. The protruding amount of the correction plate 30 is 0.1 mm to 5.0 mm, and the distance between the fixed plate facing surface 19c of the movable platen 19 before mold clamping and the back surface of the mold mounting plate 18b is the same as the protruding amount. Therefore, even if the movable platen 19 is bent to the maximum extent, it does not contact the mold mounting plate 18b and further does not deform the mold mounting plate 18b or the mold body 18a. Since the movable mold 18 is subjected to a clamping force only through the correction plate 30 fixed to the central portion of the movable plate 19 with little bending, the movable mold 18 hardly deforms, and as a result, the molded product is formed. No defect occurs. Therefore, the present invention is effective particularly when the molded product is required to have dimensional accuracy, or when the cavity is long in the vertical direction and warping of the molded product becomes a problem. Specifically, the effect is great when molding a light diffusing plate or a light guide plate.

Next, another embodiment will be described focusing on the differences. FIG. 4 is a cross-sectional view of a movable platen, a movable mold, and a correction plate according to another embodiment. In another embodiment, the thickness of the correction plate 51 having a substantially circular plate-like body is not constant. In the correction plate 51, the distance (plate thickness) between the movable plate contact surface 51a and the mold contact surface 51b is different by about 0.02 mm at both ends A and B in the diameter direction. The corrector plate 51 has an ejector hole 52 penetrating through the center, but is not provided with a hole for inserting a mounting bolt for mounting on the movable platen 19. The correction plate 51 includes a large-diameter portion 51c having a constant thickness on the movable plate contact surface 51a side and a small-diameter portion 51d having a different thickness on the mold contact surface 51b side. A step portion 51e is provided between the portion 51c and the small diameter portion 51d. Further, a ring-shaped pressing member 53 including a large-diameter hole portion and a small-diameter hole portion is separately provided so as to coincide with the step portion 51e on the outer peripheral surface of the correction plate 51. The holding member 53 has a plurality of through holes 56 for inserting mounting bolts corresponding to the bolt holes 55 provided in the fitting recess 54 of the movable platen 19. The correction plate 51 and the pressing member 53 are fitted, fitted into the fitting recess 54, and fixed by the mounting bolt 57. With such a structure, the correction plate 51 itself is not directly fixed to the movable platen 19. Therefore, the correction plate 51 can be rotated by loosening the mounting bolt 57 for fixing the presser member 53. Alternatively, the mounting bolt 57 can be removed, the presser member 53 and the correction plate 51 can be removed, and the mounting angle of the correction plate 51 can be changed.

The correction plate 51 is substantially the same in that it is provided so as to protrude from 0.1 mm to 5.0 mm with respect to the fixed plate facing surface 19 c of the movable platen 19, but when the correction plate 51 is attached to the movable platen 19, The mold contact surface 51b is not parallel to the fixed plate facing surface 19c. Specifically, the protrusion amount is different by about 0.02 mm at one end (A in FIG. 4) and the other end (B in FIG. 4) perpendicular to the mold clamping direction. The mold mounting plate 18b of the movable mold 18 is inserted into the movable platen 19 without the correction plate 51 by screwing another mounting bolt 58 into the bolt hole 59 provided in the fixed plate facing surface 19c. Directly fixed. Therefore, the back surface of the mold mounting plate 18 b of the movable mold 18 is mounted in a state where it is just in contact with the mold contact surface 51 b of the correction plate 51. In another embodiment shown in FIG. 4, by adopting such a structure, not only the above-described measures against bending of the movable platen 19 during mold clamping, but also the contact surfaces of the fixed mold 14 and the movable mold 18, etc. Even when there is a problem with the parallelism of the mold, the parallelism of the mold can be adjusted. Specifically, when the molded product is found to have a problem in the parallelism of the mold, the movable mold 18 is once removed from the movable platen 19. Then, after loosening the mounting bolt 57 of the pressing member 53, the correction plate 51 is positioned such that the portion where the thickness of the molded product is thick or the portion where the height of the correction plate 51 is higher than the portion where burrs are generated. Rotate 51. Then, the parallelism of the mold can be adjusted by fastening the mounting bolt 57 again and attaching the movable mold 18. In addition, you may provide the hole etc. for inserting the tool at the time of rotating the correction plate 51 in the metal mold | die contact surface 51b of the correction plate 51. FIG.

It is also assumed that a plurality of correction plates 51 are prepared and changed. Specifically, when there is no problem in the parallelism between the molds, it is natural to use a straightening plate with a uniform thickness, but depending on the degree of parallelism of the molds, Correction plates with different abutment surface slopes may be used. Furthermore, it is possible to change the diameter and shape of the correction plate, for example, by increasing the radial width of the pressing member to reduce the diameter of the correction plate.

Next, another embodiment will be described focusing on the differences. FIG. 5 is a cross-sectional view of a movable platen, a movable mold, and a correction plate according to still another embodiment. As shown in FIG. 5, the thickness of the correction plate 61 is not constant in another embodiment. The movable plate contact surface 61a of the correction plate 61 is slightly spherical, and the mold contact surface 61b is flat. Accordingly, the correction plate 61 has the largest thickness at the substantially center, and the thickness becomes thinner toward the outer peripheral side. The difference in thickness is about 0.02 mm. The corrector plate 61 has an ejector hole 62 formed therethrough, but is not provided with a hole for inserting a mounting bolt for attaching the corrector plate 61 to the movable platen 19. In addition, a plurality of recesses 63 are formed in the thin portion of the correction plate 61 on the outer peripheral side of the movable plate contact surface 61a. A spring 64 is disposed in the recess 63. The correction plate 61 includes a large-diameter portion 61c on the movable plate contact surface 61a side and a small-diameter portion 61d on the mold contact surface 61b side, and an outer peripheral surface between the large-diameter portion 61c and the small-diameter portion 61d. A stepped portion 61e is provided on the top. A ring-shaped pressing member 65 is separately provided so as to match the outer peripheral surface of the correction plate 61. The presser member 65 has a plurality of through holes 68 for bolt insertion corresponding to the bolt holes 67 provided in the fitting recess 66 of the movable platen 19. The correction plate 61 and the pressing member 65 are fitted, fitted into the fitting recess 66, and fixed to the movable platen 19 by mounting bolts 72. In these embodiments, a magnet may be used to fix the correction plate 61 and the like.

The correction plate 61 protrudes from 0.1 mm to 5.0 mm with respect to the fixed plate-facing surface 19c of the movable platen 19, and when the mold clamping force is not applied, the mold contact surface 61b of the correction plate 61 and the fixed plate The opposing surface 19c is provided in parallel. A through hole 69 is provided in the mold mounting plate 18 b of the movable mold 18 at the same position as the bolt hole 70 of the fixed plate facing surface 19 c of the movable plate 19. Therefore, the mold mounting plate 18 b of the movable mold 18 is directly fixed to the movable platen 19 without the correction plate 61 via the mounting bolt 71. By using the correction plate 61 having such a structure, there is a problem not only in the above-described countermeasure against bending of the movable platen 19 during mold clamping, but also in the parallelism of the contact surfaces of the fixed mold 14 and the movable mold 18. Even in this case, the parallelism of the mold can be adjusted without removing the mold. Specifically, when there is a problem with the parallelism of the mold, the amount of contraction of the spring 64 provided between the correction plate 61 and the fitting recess 66 of the movable platen 19 is different, so that the fixed mold 14 and The space between the movable molds 18 is automatically kept parallel.

Further, in still another embodiment shown in FIG. 5, even if the parallelism between the molds is satisfactory, it is effective in the following cases. That is, when the movable mold 18 attached to the movable plate 19 is large or has a long vertical length, the vertical length of the mold main body 18a becomes long. A large size is required. However, when the length of the correction plate 61 in the vertical direction is long, the vertical deflection of the movable platen 19 during mold clamping may reach the back surface portion of the correction plate 61. In such a case, by using this correction plate 61, it is possible to cope with the bending that occurs near the middle between the upper and lower ends of the movable platen 19 and the central portion, and to further deform the movable platen 19 into the movable mold 18. It can be reduced. Although the correction plate 61 is a substantially circular plate-like body, in the case of a substantially square shape, the movable plate abutting surface has a cross section so that the thick plate portion becomes horizontal in the center when attached and becomes thin in the vertical direction. A curved surface is provided, and a plurality of springs are provided in the thin portion. Further, the correction plate 61 may have a plane parallel to the mold contact surface 61b only at the substantially central portion of the movable plate contact surface 61a. And about a spring, it is not limited to a string wound spring, Other springs and elastic members other than a spring may be sufficient.

In each of the embodiments shown in FIGS. 1 to 5, the diameter D of the insertion portion 81 (mortar portion) of the injection device 13 provided on the non-movable platen surface (injection device side) of the fixed platen 15 is the correction plate. It is desirable to make it approximately the same as 30 or smaller. As a result, the clamping force exerted on the stationary platen 15 via the stationary mold 14 from the movable mold 18 side is received by the entire stationary platen 15 without concentrating stress on the thin portion 82 formed by the insertion portion 81. The phenomenon that the mold center part is pushed toward the fixed platen 15 can be prevented.

The above-described embodiments are all described as an example of a horizontal injection molding machine in which the movable platen 19 moves in the horizontal direction. However, the embodiment deviates from the gist of the present invention, such as a vertical injection molding machine in which the movable platen moves in the vertical direction. It goes without saying that various modifications can be added within the range not to be performed.

It is a schematic explanatory drawing of the injection molding machine with which the correction plate was attached. It is sectional drawing of a movable board, a movable metal mold | die, and a correction plate, Comprising: It is a figure which shows the cross section of the AA in FIG. It is a front view which shows the positional relationship of a movable board, a movable metal mold | die, and a correction plate. It is sectional drawing of the movable board of another embodiment, a movable metal mold | die, and a correction plate. It is sectional drawing of the movable board of another embodiment, a movable metal mold | die, and a correction plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Clamping apparatus 14 Fixed mold 15 Fixed board 18 Movable mold 18a Mold main body part 18b Mold mounting plate 19 Movable board 19c Fixed board opposing surface 20 Toggle mechanism 21 Servo motor 30, 51, 61 for mold clamping Correction plate 30a Movable plate contact surface 30b Mold contact surface 32 Fitting recess 32a Correction plate mounting surface

Claims (4)

In a mold clamping device of an injection molding machine that performs mold clamping by moving a movable plate with a movable die attached to a fixed plate with a fixed die attached thereto by a toggle mechanism.
In the central portion of the fixed plate facing surface of the movable plate, a correction plate is provided that protrudes from the fixed plate facing surface and is fixed directly by a bolt or via a pressing member, and disposed .
Another bolt is fixed to the bolt hole around the correction plate of the movable plate without being inserted into the correction plate through the screw-free through hole of the mold mounting plate of the movable mold, thereby correcting the correction plate. A mold clamping device for an injection molding machine , wherein a movable mold is fixed to the front surface of the mold. 2. The injection molding machine according to claim 1, wherein the correction plate is a substantially circular plate-like body, and is disposed in a fitting recess formed one step deeper than a fixed plate facing surface of the movable plate. Clamping device. The mold clamping device for an injection molding machine according to claim 1 or 2, wherein an amount of protrusion of the correction plate from the fixed plate facing surface is 0.1 mm to 5.0 mm. The mold contact surface when the correction plate is attached to the movable mold is not parallel to the fixed plate facing surface of the movable platen, according to any one of claims 1 to 3. Clamping device for injection molding machines.

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