JP2011011483A - Mold clamping device of molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that parallelism between a fixed side and a movable half of a mold in impaired due to the compression of a heat insulating plate by a clamping force since the mold is tightly fixed by a mold fitting member during the fitting of the mold following procedures to mount the fixed side part and the movable half of a mold on a fixed platen and a supporting platen connected by a tie bar and a movable platen moving between the fixed platen and the supporting platen respectively, through each heat insulating plate fitted directly to both fixed and movable platens.SOLUTION: This mold clamping device of the molding machine has heat insulating spacers which are formed of materials of high Young's modulli, and has a larger thickness than the thickness of the heat insulating plate. In addition, the heat insulating spacers are inserted into a plurality of through-holes for the heat insulating spacers which penetrate the heat insulating plate in its thickness direction, and the through-holes for the heat insulating spacers are formed in a region which the mold on the surface of the heat insulating plate faces, and each formed at a line symmetric position about the straight line in the up-and-down direction and the right and left direction, and passes through the center point of the region.

Description

  In the mold clamping device of the injection molding machine, in order to suppress the heat transmitted from the mold device to the platen, even if a heat insulating plate is provided between them, the fixed mold and the movable side mold are provided. The present invention relates to a mold clamping device capable of maintaining parallelism with high accuracy.

  In general, an injection molding machine includes at least an injection device and a mold clamping device, and plasticizes and melts the resin material while heating with the injection device, and the molten resin is injected at a high pressure and mounted on the mold clamping device. The mold is filled into a cavity, and the molten resin in the cavity is cooled and solidified to obtain a molded product.

  The mold clamping device of the injection molding machine includes a fixed platen and a back platen connected by a tie bar, a movable platen that moves between them, and a drive device that moves the movable platen back and forth and presses it against the fixed platen. Prepare on the machine base.

  The fixed platen is mounted with a fixed side of the mold apparatus (hereinafter referred to as a fixed side mold), and the movable platen is mounted with a movable side of the mold apparatus (hereinafter referred to as a movable side mold). . The mold apparatus is attached by fixing the fixed side mounting plate provided in the fixed side mold and the movable side mounting plate provided in the movable side mold to the platen with a mold mounting member, that is, a clamp member or a direct bolt. Is called. Then, the driving device opens and closes the movable side mold together with the movable platen to open and close the mold with respect to the fixed side mold, and presses and clamps the mold.

  In many cases, the mold apparatus mounted on the platen is adjusted to a predetermined temperature. For example, when molding a precision molded product such as a lens, the temperature is often adjusted to a relatively high temperature of about a few hundred degrees. Therefore, a temperature control pipe for circulating a heat medium such as water or oil whose temperature is adjusted by a mold temperature controller installed outside the mold apparatus is provided inside the mold apparatus. Note that a heater may be used when higher temperature control is required.

  Therefore, as in Patent Document 1, a heat insulating plate is sandwiched between the mold apparatus and the platen so that the heat of the mold apparatus is not transmitted to the platen. The heat insulating plate is formed so that the fixed side and the movable side mounting plate provided in the mold apparatus cover at least a portion facing the platen, and suppresses heat from escaping from the temperature-controlled mold apparatus to the platen. As a result, the mold apparatus quickly rises to a predetermined temperature, the temperature adjustment of the mold apparatus is stabilized, and energy is saved without unnecessary heat energy loss. In addition, the heat insulating plate prevents the platen from being thermally expanded and distorted by the heat transmitted from the mold apparatus, and further prevents the entire injection molding machine from being distorted. Furthermore, it prevents damage and rust on the platen mold mounting surface.

  Such a heat insulating plate is conventionally made by adding a binder to a glass fiber or the like as a main base material, and has low processing accuracy and low parallelism on both sides, so that precision such as a lens is used. In molding, there is a fear that molding with sufficiently high accuracy cannot be performed. Therefore, in Patent Document 2, a heat insulating layer made of ceramics is integrated with a mold mounting surface of a fixed and movable platen from the viewpoint that it is a material having high strength, durability, and heat insulation, and can improve surface accuracy. Discloses a molding machine. Therefore, the processing accuracy of the heat insulating layer is increased, the parallelism between the mounting surfaces is improved, and a precise molded product is molded with high clamping accuracy. In addition to Patent Document 2, there is also one in which a heat insulating plate formed entirely of ceramics is fixed to a platen.

Japanese Utility Model Publication No. 03-108414 JP 2006-142687 A

  However, the applicant of the present application still considers room for improvement. As described above, in precise molding, when the mold apparatus is attached to the platen of the mold clamping apparatus, high accuracy is required for the parallelism between the fixed mold and the movable mold. For example, in the molding of a spherical lens, when a molded product in a cavity of a mold apparatus is opened and taken out, the mold is opened with a low degree of parallelism between the fixed mold and the movable mold. In this case, immediately after the start, a part of the spherical lens surface and a part of the cavity surface are released from the mold, and after the other is adhered, the mold is completely released. Although the molded product immediately after the mold opening is solidified, it is an elastic body having a certain amount of heat. Therefore, the part to be released first on the surface of the spherical lens is released by being pulled, and the part may be deformed although it is fine. In the spherical lens thus molded, it is said that the upper and lower cross-sections and the left and right cross-sections do not have the same shape, and astigmatism, that is, a phenomenon in which light is dispersed without intersecting at one point.

  In addition to the reasons described above, the reason why the parallelism between the fixed side mold and the movable side mold is reduced when the mold apparatus is attached to the platen with the heat insulating plate sandwiched therebetween is not limited to the reason described above. There is non-uniform compression of the thermal insulation plate that occurs by fixing multiple locations of the mold apparatus to the platen with a mold mounting member. The fixed-side mold and the movable-side mold each have a fixed-side and a movable-side mounting plate, and the fixed platen and the movable platen are arranged so that a plurality of peripheral portions of the mounting plate are tightened to the platen side by a mold-attaching member. Fixed to each. Therefore, the portion of the heat insulating plate that is tightened by the mold attachment member is compressed toward the platen side. For example, it is assumed that the worker fixes the peripheral portions of the fixed side and movable side mounting plates in a total of four places, two on the upper and lower sides with respect to the operation side and the half operation side of the mold clamping device, respectively. . Then, the portions of the heat insulating plate facing the four places are compressed by different amounts depending on the tightening condition of the respective mold mounting members. For example, a conventional heat insulating plate mainly made of glass fiber or the like may be compressed by about 30 μm at maximum in the thickness direction. Therefore, the parallelism between the fixed side mold and the movable side mold varies depending on the tightening degree of the mold mounting member of the operator.

  For this reason, it is necessary to correct the parallelism between the fixed side mold and the movable side mold after the mold apparatus is attached to the platen, which increases the time-consuming work. The parallelism correction method is performed by adjusting the clamping force of the mold apparatus by the mold mounting member. In some cases, the mold attachment member is loosened and the parallelism is deteriorated during repeated molding.

  If the material of the heat insulating plate is made of high-strength ceramics, the amount of compression relative to the thickness of the heat insulating plate when the mold apparatus is attached to the platen can be reduced, and the parallelism between the fixed side and movable side molds can be reduced. It can be maintained with high accuracy. However, a heat insulating plate made of ceramics is more expensive than a heat insulating plate made mainly of glass fibers, and the heat conductivity of the heat insulating plate made mainly of glass fibers is 0.3 (W / (M · k)), on the other hand, even among zirconia, which has a low thermal conductivity among ceramics, there is a portion inferior in heat insulation performance of about 3 (W / (m · k)).

  Therefore, the present invention is for solving the above problems, and when the mold apparatus is attached to the mold clamping apparatus in a form in which a heat insulating plate is sandwiched between the platen of the mold clamping apparatus and the mold apparatus, The present invention proposes a mold clamping device for an injection molding machine including a heat insulating plate that achieves high heat insulating performance and low price while maintaining parallelism between a fixed mold and a movable mold with high accuracy.

  In order to solve the above problems, a mold clamping device of the present invention includes a fixed platen and a support platen connected by a tie bar, and a movable platen that moves between the platens, and is attached to the fixed platen. The fixed mold is attached from above the insulated plate, the movable mold is installed from above the insulated plate attached to the movable platen, and the fixed mold is attached when the mold is installed. And a mold for clamping the movable side of the mold so that the movable mold is clamped by a mold mounting member, the mold is made of a material having a large Young's modulus and has a thickness dimension larger than the thickness dimension of the heat insulating plate. The formed heat insulating spacer is inserted into a plurality of heat insulating spacer through holes penetrating the heat insulating plate in the thickness direction, and the heat insulating spacer through holes are inserted. A region where the mold on the plate surface of the insulating plate facing is formed at a position axisymmetric with respect to the vertical direction and the lateral direction line passing through the center point of the region.

  The material of the heat insulating spacer of the present invention is preferably ceramic.

  The material of the heat insulating spacer of the present invention is preferably zirconia among ceramics.

  Further, the heat insulating spacer of the present invention may be a disc shape or a cylindrical shape, and may have a through hole serving as a hook hole at the axis.

  According to the mold clamping device of the molding machine of the present invention, when the mold apparatus is attached from above the heat insulating plate attached to the platen, the heat insulating material is formed of a material having a large Young's modulus and has a thickness dimension larger than that of the heat insulating plate. A spacer is provided so as to penetrate through a predetermined position of the heat insulating plate, and the mold device is not brought into contact with the heat insulating plate itself, but is brought into contact only with the heat insulating spacer having a small compression amount. Thus, the parallelism between the fixed mold and the movable mold can be maintained with high accuracy. By reducing the area of the contact surface of the heat insulating spacer that contacts the mold device by the heat insulating spacer, or by reducing the number of heat insulating spacers that contact the mold device, the mold device can move from the plate device to the platen. The heat conduction can be reduced and the heat insulation effect can be enhanced. And even if the heat insulating spacer is an expensive material, it is sufficient that the heat insulating spacer has a size that comes into contact with a part of the surface facing the heat insulating plate side of the mold apparatus. It can be made much cheaper than making the entire adiabatic, such as abutting.

  In addition, according to the mold clamping device of the molding machine of the present invention, the amount of compression of the heat insulating spacer itself is reduced by using high-strength ceramics as the material of the heat insulating spacer, and the fixing device attached to the mold clamping device. Parallelism between the side mold and the movable mold can be maintained with high accuracy.

  Further, according to the mold clamping device of the molding machine of the present invention, the material of the heat insulating spacer is made of zirconia having a low thermal conductivity among ceramics, so that the clamping force when mounting the mold device and the mold clamping device can be reduced. When the clamping force is large and the contact surface of the heat insulating spacer that contacts the mold device must be increased, the area can be increased without impairing the heat insulating performance.

  Further, according to the mold clamping device of the molding machine of the present invention, the heat insulating spacer is formed into a disk shape or a cylindrical shape, so that the processing is facilitated, and the through hole is formed in the shaft center, whereby the platen Even when the heat insulating plate is attached to the shaft, it is possible to easily remove the heat insulating spacer by hooking a rod or the like into the through hole of the shaft center portion.

It is the elevation which looked at the mold clamping device of the molding machine of this invention schematically and was seen from the operation side. FIG. 2 is an elevational view including a partial cross-sectional view in which portions of a fixed platen and a movable platen in FIG. 1 are enlarged. It is an AA arrow line view of the fixed platen of FIG. 2 (a dotted line shows a mode that the fixed side metal mold | die was attached on the heat insulation board). It is a BB arrow line view of the movable platen of FIG. 2 (a dotted line shows a mode that the movable side metal mold | die was attached on the heat insulation board). 3A is a cross-sectional view taken along the line C-C in the vicinity of the heat insulating spacer on the fixed side in FIG. 3 (the parenthesis indicates the case where it is replaced with the movable side), and FIG. A view on arrow D is shown. FIG. 3A is another embodiment of the heat insulating spacer of the present invention, and FIG. 3A shows a CC cross-sectional view in the vicinity of the heat insulating spacer on the fixed side of FIG. (B) and (b) show the EE arrow view of (a).

  A mold clamping device of an injection molding machine of the present invention is shown in FIGS. FIG. 1 is an elevational view of an injection molding machine according to an embodiment of the present invention as viewed from the operation side, schematically showing a mold clamping device. FIG. 2 is an elevational view including a partial cross-sectional view in which portions of the fixed platen and the movable platen in FIG. 1 are enlarged. FIG. 3 is an AA arrow view of the fixed platen of FIG. 2 (the dotted line shows a state where the fixed mold is attached on the heat insulating plate). FIG. 4 is a BB arrow view of the movable platen of FIG. 2 (dotted lines indicate a state in which the movable mold is attached on the heat insulating plate). 5A is a cross-sectional view taken along the line CC in the vicinity of the heat insulating spacer on the fixed side in FIG. 3 (the parenthesis indicates a case where the bracket is replaced with the movable side), and FIG. ) Shows a DD arrow view. FIG. 6 is another embodiment of the heat insulating spacer of the present invention, and FIG. 6 (a) is a cross-sectional view taken along the line CC in the vicinity of the heat insulating spacer on the fixed side in FIG. (The case where it replaces is shown), FIG.5 (b) shows the EE arrow line view of a figure (a). 1 to 6, the direction of the operation side or the counter-operation side of the mold clamping device is referred to as the left-right direction, and the direction of the upper side or the lower side of the mold clamping device in each drawing is referred to as the up-down direction.

  The mold clamping device 1 includes a fixed platen 11 and a back platen 12 connected by a tie bar 10, a movable platen 13 that moves between the platens, and a drive that moves the movable platen 13 forward and backward relative to the fixed platen 11 and presses it. The device 14 is provided on the machine base 2. The fixed platen 11 is attached with a fixed mold 20 a of the mold apparatus 20, and the movable platen 13 is attached with a movable mold 20 b of the mold apparatus 20. The mold apparatus 20 is attached by being fastened to the fixed platen 11 side or the movable platen 13 side by a plurality of mold attachment members 16. The drive device 14 is a device that opens and closes the movable platen 13 together with the movable mold 20b, opens and closes the mold, and presses and clamps the mold. For example, a hydraulic or electric hydraulic drive direct pressure mold clamping apparatus or a toggle mold clamping is used. There are devices. An injection device 3 (whose overall view is omitted) for plasticizing and injecting a molding material is disposed on the fixed platen 11 side of the mold clamping device 1.

  The fixed platen 11 and the movable platen 13 are installed so that their mold mounting surfaces 11a and 13a facing each other maintain a highly accurate parallelism. For example, the movable platen 13 that advances and retreats with respect to the fixed platen 11 is a type in which the tie bar 10 is passed through linear bushes 18 provided at the four corners of the movable platen, or a linear guide provided on the machine base. There is a type to put the lower end of. Accordingly, the straightness of the movable platen 13 that advances and retreats is improved, and the parallelism between the fixed platen 11 and the movable platen 13 is maintained.

  Furthermore, although not shown in the figure, the three platens are supported on the machine base by the support members at the upper and lower center positions, the fixed platen and the support platen are fixed to the machine base, and the movable platen is suspended on the tie bar. The guide plate is guided by the linear guide on the machine base, and the three platens are fitted with a reference member that regulates the displacement in the transverse direction perpendicular to the mold opening / closing direction at the center position of the lower end surface. There are types. As a result, even if the temperature of the three platens and the surroundings changes, the thermal elongation generated in the platens themselves extends symmetrically up and down and left and right with respect to the center position, and the center between the fixed platen and the movable platen. Some do not upset the position and parallelism both vertically and transversely.

  The fixed platen 11 is formed with a hole 11b through which the locating ring 21 of the mold apparatus 20 is fitted and the injection nozzle 3a of the injection apparatus 3 is inserted at the center position thereof. In addition, the movable platen 13 is formed with a hole 13b through which an ejector rod 17 of a protruding device (not shown) is passed at the center position or a predetermined position. The fixed platen 11 and the movable platen 13 are provided with screws 32a for fixing a heat insulating plate 30 to be described later and screw holes for tightening bolts 16c such as a mold mounting member to be described later.

  The fixed side mold 20a and the movable side mold 20b are attached to the fixed platen 11 and the movable platen 13 through the heat insulating plates 30, respectively. The mold apparatus 20 includes a temperature adjustment pipe (not shown) for maintaining the temperature of the mold apparatus 20 itself at a set temperature. A piping (not shown) extending from an external temperature controller is connected to the piping, and a heat medium such as water or oil whose temperature is adjusted is circulated. 22a is a fixed-side mounting plate provided on the fixed platen 11 side of the fixed-side mold 20a. Reference numeral 22b denotes a movable side mounting plate provided on the movable platen 13 side of the movable side mold 20b. Of course, the fixed mold 20a and the movable mold 20b are formed with high accuracy in parallelism of the platen-side surfaces 23a and 23b and the parting surfaces.

  The fixed side mold 20a and the movable side mold 20b are attached by using a plurality of mold attachment members 16 so as to tighten a plurality of locations on the peripheral portions of the fixed side attachment plate 22a and the movable side attachment plate 22b. The mold mounting member 16 includes, for example, a device composed of a pine bark 16a, a plaster member 16b, and a fastening bolt 16c. The Matsuba material 16a is formed of a plate or two parallel square bars, and has a hole or space through which the fastening bolt 16c is passed in the middle. The plaster material 16b is a member having a thickness dimension that is the same as the thickness dimension of the fixed side mounting plate 22a and the movable side mounting plate 22b. Therefore, the device tightens the matba material 16a against the platens 11 and 13 with one end of the matba material 16a pressing the fixed side mounting plate 22a or the movable side mounting plate 22b and the other end pressing the plaster material 16b. The mold apparatus 20 is fixed by tightening with the bolt 16c.

  From here, the specific configuration of the present invention will be described. In the present invention, in the mold clamping device 1 of the molding machine, a heat insulating plate 30 including a heat insulating spacer 40 described later is attached to the fixed platen 11 and the movable platen 13, and the mold device 20 is attached from above the heat insulating plate 30. The heat insulating plate 30 includes a heat insulating spacer through hole 31 into which the heat insulating spacer 40 is inserted, and a heat insulating plate mounting through hole 32 for passing the screw 32a for fixing the heat insulating plate 30 to the platens 11 and 13. A predetermined number of through holes 33 for mold attachment members for passing the fastening bolts 16c of the mold attachment member 16 are formed at predetermined positions. In addition, the locating ring 21 of the fixed mold 20a is fitted at the center of the heat insulating plate 30a attached to the fixed side, and the locating ring through-hole 34 for passing the injection nozzle 3a of the injection device 3 is inserted. Is formed. Further, the heat insulating plate 30b attached to the movable side is formed with a through hole 35 for an ejector rod through which the ejector rod 17 of a protruding device (not shown) passes at the center position or a predetermined position.

The heat insulating plate 30 is attached to the fixed platen 11 and the movable platen 13 by screwing one place on each of the upper side, the lower side, the operation side, and the counter-operation side. A plurality of through holes 31 for heat insulating spacers are formed in the heat insulating plate 30 in a region 36 facing the mold apparatus 20, and the heat insulating spacers 40 are inserted and inserted into the holes 31. As shown in FIG. 5, the heat insulating spacer 40 has a thickness dimension d _s larger than the thickness dimension d _{d of the} heat insulating plate 30 (the fixed side is 30a and the movable side is 30b) (d _s > d _d ), and the platen 11 , 13 protrudes from the surface of the heat insulating plate 30 on the mold device 20 side until it is fitted. The thickness dimension d _s of the heat insulating spacer is preferably 0.1 (mm) to 0.5 (mm) larger than the thickness dimension d _d of the heat insulating plate. Then, the mold apparatus 20 is configured such that the upper and lower sides on the operation side and the upper and lower sides on the opposite side of the mold side are fixed to the fixed side and movable side attachment plates 22a and 22b of the mold apparatus. And is attached to the fixed platen 11 and the movable platen 13 from above the heat insulating plate 30. At that time, the compression amount [Delta] d _s of the insulating spacer 40 is compressed by the clamping force of the mold mounting member 16, the amount before mounting the mold apparatus, in which the insulating spacer 40 is protruded from the insulating plate 30 (= d _s -d _d) smaller than that of the _{(Δd s <(d s -d} d)). Then, the compression amount [Delta] d _s is may be in the order of several [mu] m. Therefore, the heat insulating spacer 40 is made of a material having a large Young's modulus.

As a result, even if the mold apparatus 20 is attached to the fixed and movable platens 11 and 13 from above the heat insulating plate 30, it is brought into contact only with the heat insulating spacer 40 and not with the heat insulating plate 30 itself. Insulating spacer 40, the glass fibers and the like by the compressed amount [Delta] d _s in comparison with the heat insulating plate as a main base material is small, while the fixed mold 20a and a movable mold 20b which occurs during the mounting of the mold apparatus 20 It is possible to prevent the deviation of the parallelism and maintain the parallelism with high accuracy.

Further, the heat insulating spacer 30 formed of a material having a large Young's modulus is the total area of the contact surfaces 41 of all the heat insulating spacers 40 that contact the fixed-side mold 20a, or all that contacts the movable-side mold 20b. The total area of the contact surfaces 41 of the heat insulating spacers 40 can be made smaller than the area of the surface of the mold apparatus 20 on the heat insulating plate side. Therefore, for example, the entire surface 23a (the area S _d ) on the fixed platen 11 side excluding the locating ring 21 of the fixed mold 20a as in the prior art is insulated with glass fiber having a low thermal conductivity as a main base material. Compared with the heat insulation effect when heat insulation is performed by abutting with a plate, only a plurality of heat insulating spacers 40 made of a material having a higher thermal conductivity than conventional ones are provided only on a predetermined portion of the surface 23a on the fixed platen 11 side. The heat insulation effect when the heat insulation is performed by making contact with each other is obtained by adding the total area S _a of the contact surfaces 41 of the heat insulation spacers 30 that contact the mold 20a (the area S _{s of the} contact surface per one). By making it smaller, it becomes possible to adjust to the same or higher. Even if the material of the heat insulating spacer 40 is expensive, it is not necessary to cover the entire surface of the mold apparatus 20 facing the heat insulating plate 30, so that the price can be kept low.

  Further, the position where the heat insulating spacer 40 abuts on the mold device 20 is determined by being inserted into the through hole 31 for the heat insulating spacer formed in the region 36 of the heat insulating plate 30 facing the mold device 20. The The position of the through hole 31 is in a region 36 facing the mold apparatus 20 on the plate surface of the heat insulating plate 30, and with respect to the vertical and horizontal lines passing through the center point 37 on the plate surface. Are formed at line-symmetric positions. This is because the pressure applied to the mold apparatus 20 is equal on the upper side and the lower side when the mold is attached or clamped, and is equalized on the right side (operation side) and the left side (counter operation side). . The position is preferably at least a position where the mold apparatus 20 is fastened by the mold mounting member 16 or a position in the vicinity thereof. This is to prevent the mold from being bent with the contact position of the heat insulating spacer 40 as the apex depending on the positions of the heat insulating spacer 40 and the mold mounting member 16. Further, the position may be at a position on the extension line with respect to the resin flow path extending in the axial direction in the mold apparatus 20.

  Further, the number of through holes 31 for the heat insulating spacer 40 may be formed in advance more than the number of the heat insulating spacers 40 so that the position of the heat insulating spacer 40 can be changed by inserting and removing it. In order to insert and remove the heat insulating spacer 40, a hook hole 42 is preferably formed in the axial center of the heat insulating spacer 40 as shown in FIG. The heat insulating plate 30 may be made of any material as long as the mold mounting member 16 can be used, various through holes can be formed, and the radiant heat from the mold apparatus 20 can be insulated. For example, the heat insulating plate 30 may be a conventional heat insulating plate mainly made of glass fiber or the like.

Hereinafter, the fixed side mold 20a of the mold apparatus 20 will be described in more detail as an example. The fixed-side mounting plate 22a provided in the fixed-side mold 20a has a surface 23a on the fixed-side heat insulating plate 30a side having one side L _x = L _y = 170 (mm), and the locating ring 21 is provided at the center of the surface 23a. Prepare. A through hole 34 having an inner diameter R _r = 42 (mm) for fitting the locating ring 21 is formed in the heat insulating plate 30a on the fixed side. Conventionally, the surface 23a on the fixed side heat insulating plate 30a side of the fixed side mounting plate 22a excluding the portion of the locating ring 21 is in contact with the heat insulating plate 30a. The contact area S _d is
_{S d = L x · L y} -π · (R r / 2) 2 = about 27515 ^(mm 2)
It is said. Incidentally, the conventional heat insulating plate is mainly made of glass fiber having a thermal conductivity λ _d = about 0.3 (W / (m · k)), and has a thickness dimension d _d = 10 (mm ) Is assumed.

In the present invention, a heat insulating plate 30 in which a heat insulating spacer 40 is inserted into the main body of the heat insulating plate is used instead of the conventional heat insulating plate. The heat insulating plate 30 uses the above-described conventional glass fiber or the like as a main base material, and has a thickness dimension d _d = 10 mm. The main body of the heat insulating plate 30 does not come into contact with the mold apparatus 20, but is necessary to install the heat insulating spacer 40 at a predetermined location and prevent radiant heat from the mold apparatus 20. In addition, about the material of the heat insulation board 30 main body, it is not limited to what uses glass fiber etc. as a main base material.

The heat insulating spacer 40 actually in contact with the fixed mold 20a is made of zirconia having a thermal conductivity λ _s = about 3 (W / (m · k)) of ceramics, and has a thickness dimension d _s = 10. N = 8 discs or cylinders of 1 (mm) are prepared. The zirconia is a material having a high Young's modulus (E _s = 206 (GPa)) and a low thermal conductivity among ceramics. However, the thermal conductivity λ _s of zirconia is about 10 times that of the conventional thermal insulation plate λ _d . Therefore, in order to realize the heat insulating effect of the conventional heat insulating plate with the heat insulating spacer 40 made of zirconia, in this embodiment, the difference in the thickness dimension between the conventional heat insulating plate and the heat insulating spacer 40 is different by about 0.1 (mm). so, insulating spacer 40 is a total area S _a of the area in contact with the fixed mold 20a, conventional insulation plate may be about one tenth of the fixed die 20a abutting area S _d. Therefore, the total area S _a of the area of all insulating spacer 40 abuts the stationary mold half 20a is,
S _a = S _d · (d _s / d _d ) · (λ _d / λ _s ) = about 2779 (mm ² )
It is said. Therefore, in this embodiment, when the number of the fixed-side heat insulating spacers 40 is n = 8, the area S _{s of the} surface 41 in contact with the fixed-side mold 20a per one of the heat insulating spacers 40 is
S _s = S _a / n = about 347 (mm ² )
It is said. Here, since the heat insulating spacer 40 of the present embodiment is formed in a disk shape or a cylindrical shape, the outer diameter R _s thereof is
R _s = 2 · {√ (347 / π)} = about 20 (mm)
It is said. The inner diameter of the through hole 31 for the heat insulating spacer formed in the heat insulating plate 30a is preferably formed such that the heat insulating spacer 40 having the outer dimension R _s can be inserted and fitted and extracted.

In the above, first, each dimension of the heat insulating spacer 40 was obtained by calculation based on the thermal conductivity. Next, it is confirmed how much the heat insulating spacer 40 is compressed by being loaded with the clamping force of the mold mounting member 16 and whether each dimension is appropriate. In addition, the disk-shaped heat insulating spacer 40 has a thickness dimension d _s = 10.1 (mm) and an outer diameter R _s = 20 (mm). The area S _s is
S _s = π · (R _s / 2) ² = 314 (mm ² )
And And n = 8 heat insulating spacers 40 are used on the fixed side.

The fixed-side mold 20a is configured such that the peripheral edge portion of the fixed-side mounting plate 22a provided on the fixed platen 11 side of the mold is fastened to the fixed platen from the top of the heat insulating plate 30a with a plurality of mold mounting members 16. It is attached to the mold clamping device 1. In the embodiment, the fixed-side mounting plate 22a is clamped with a total of m = 4 mold mounting members 16 on the upper and lower sides of the operation side and the half-operation side of the mold clamping device 1 so that the upper side of the heat insulating plate 30a. It is attached from. One mold mounting member 16 is assumed to use one M10 bolt as the fastening bolt 16c. The bolt 16c has a 2.4 series, an outer diameter R = 10 (mm), and a basic torque (tightening torque) T = 59 (N · m). When the torque coefficient k = 0.2, the bolt axial force N per bolt is
N = T / (R · k) = 29.5 (kN)
It becomes. Then, because it uses m = 4 pieces of the mold mounting member 16, a bolt axial force N _a which is the sum of the bolt axial force of four is
N _a = m · N = 118 (kN)
It becomes.
Accordingly, the tightening force P _c received by each heat insulating spacer is:
P _c = N _a / (n · S _s ) = about 47 (MPa)
It becomes. Since the heat insulating spacer 40 of this embodiment is formed of zirconia in ceramics, its Young's modulus E _s = 206 GPa as described above. From that, the strain rate ε _s of the heat insulating spacer is
ε _s = P _c / E _s = about 0.00023
It becomes.
Therefore, the compression amount [Delta] d _s to the thickness dimension of the insulating spacer,
Δd _s = ε _s · d _s = 2.3 (μm)
It becomes. Incidentally, the compression amount Δd _s = 5 (μm) is when the tightening torque T = 129 (N · m) per tightening bolt 16c, that is, approximately twice the basic torque.

The heat insulating spacer 40 is loaded with a clamping force by a clamping device in addition to the clamping force by the mold mounting member 16. In this embodiment, the maximum clamping force P _{p of the} mold clamping device 1 is set to 98 (kN) based on the molded product to be molded and the size of the mold device 20 thereof. When the maximum mold clamping force P _p is applied, the pressure P _s received by one heat insulating spacer 40 is
P _s = P _p / (n · S _s ) = 39 (MPa)
It becomes.
The strain rate ε _s of the heat insulating spacer at that time is
ε _s = P _s / E _s = about 0.00019
It becomes.
Therefore, the compression amount [Delta] d _s to the thickness dimension of the insulating spacer,
Δd _s = ε _s · d _s = 1.9 (μm)
It becomes. Even when the maximum mold clamping force P _p is applied, the compression amount of the heat insulating spacer 40 is small.

  So far, the fixed-side mold 20a and the fixed-side heat insulating plate 30a have been described as examples, but the same applies to the movable-side mold 20b and the movable-side heat insulating plate 30b. In the case of the movable side mold 20b, the portion of the through hole 35 through which the ejector rod 17 passes is a place where the movable side mold 20b and the heat insulating plate 30b are not in contact with each other. Usually, the same number, the same shape, and the same size of the heat insulating spacers 40 on the fixed side and the movable side may be used at the same position. However, the present invention is not limited to this, and the shape, size, and number of the heat insulating spacers 40 may be different between the fixed side and the movable side, and the positions that contact the mold may be different. Moreover, although it demonstrated so that the heat insulation board 30 provided with the heat insulation spacer 40 could be attached to both the fixed side and the movable side, either one of the fixed side or the movable side may be used. In the embodiment, the disk-shaped or cylindrical heat insulating spacer 40 has been described. However, the shape may be formed as necessary.

From the top of the heat insulating plate 30 the mold apparatus 20 is provided with a heat insulating spacer 40, as described above, be secured to the platen 11 and 13 with the mold mounting member 16, the compression amount [Delta] d _s of the heat insulating spacer 40, Pressed to several μm. Therefore, as in the prior art, when the mold apparatus 20 is attached, the heat insulating plate 30 is compressed, and the parallelism between the fixed mold 20a and the movable mold 20b is prevented from being distorted. Can be maintained with high accuracy. In addition, the heat insulating effect is equivalent to the effect of the conventional heat insulating plate, and the heat transmitted from the heated mold apparatus 20 is sufficiently suppressed to be transmitted to the platens 11 and 13, so that the molds such as the platens 11 and 13 are used. The distortion of the fastening device 1 can be suppressed.

DESCRIPTION OF SYMBOLS 1 Clamping apparatus 11 Fixed platen 13 Movable platen 16 Mold attachment member 20a Fixed side mold 20b Movable side mold 22a Fixed side mounting plate 22b Movable side mounting plate 30 Heat insulating plate 30a Fixed side heat insulating plate 30b Movable side heat insulating plate 31 Through hole for heat insulating spacer of heat insulating plate 33 Through hole for die mounting member of heat insulating plate Through hole 35 for locate ring of fixed heat insulating plate Through hole 36 for ejector rod of movable heat insulating plate Region 40 of the plate facing the mold apparatus Heat insulating spacer 41 Surface of the heat insulating spacer contacting the mold apparatus 42 Hook hole R of the heat insulating spacer _s External dimension d of the heat insulating spacer d _s Thickness dimension of the heat insulating spacer d _dd thickness dimension of the heat insulating plate

Claims (4)

A fixed platen and a support platen connected by a tie bar, and a movable platen that moves between the platens, and a fixed mold is attached to the movable platen from above the heat insulating plate attached to the fixed platen. A movable mold is attached from above the attached heat insulating plate, and when the mold is attached, the fixed mold and the movable mold are fixed so that they are clamped by a mold attachment member. In the mold clamping device of the molding machine
A heat insulating spacer formed of a material having a large Young's modulus and having a thickness larger than the thickness of the heat insulating plate is inserted into through holes for a plurality of heat insulating spacers that penetrate the heat insulating plate in the thickness direction. And
The through-hole for the heat insulating spacer is in a region on the plate surface of the heat insulating plate facing the mold, and is symmetrical with respect to the vertical and horizontal straight lines passing through the center point of the region. A mold clamping device for a molding machine, wherein the mold clamping device is formed respectively.   2. The mold clamping apparatus for a molding machine according to claim 1, wherein a material of the heat insulating spacer is ceramic.   The mold clamping device for a molding machine according to claim 2, wherein the material of the heat insulating spacer is zirconia of ceramics.   4. The mold clamping apparatus for a molding machine according to claim 1, wherein the heat insulating spacer has a disk shape or a cylindrical shape, and has a through hole serving as a hook hole at an axis thereof.

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