JP4714705B2 - Molding device for injection molding machine - Google Patents

Description

  The present invention relates to a mold clamping device of an injection molding machine provided with means for adjusting misalignment between molds attached to a fixed platen and a movable platen.

  In a normal horizontal mold clamping device, a slight deviation in parallelism may occur depending on the assembly at the time of manufacture. Also, the tie bar is bent by the load of the movable plate, the mold clamping force, the nozzle touch force, the injection pressure, etc. Distortion and bending of the movable platen or fixed platen due to external force, as well as temperature rise of the mold or thermal expansion deformation of the movable platen due to heat transfer from the mold filled with molten resin, may occur between the movable platen and the fixed platen. It may cause an error in parallelism. The misalignment between the molds due to the deviation in parallelism is slight, and even though it is not so great as to cause problems such as biting, it is not preferable for molds that are repeatedly opened and closed, and is very small (unit: μm). In the molding of precision molded products that require a high dimensional accuracy, this becomes a cause of defective molding.

  As a means for preventing distortion or bending due to mechanical or thermal expansion deformation in the fixed plate and movable plate, a fixed plate base having a concave plate shape is installed on the machine base, and support pillars on both ends of the fixed plate base. In addition, the fixed plate with the temperature control circuit is fixed at the center of both sides and installed vertically with an expansion gap in the fixed plate base, while the guide plate is on the operation side and the non-operation side on the machine base. There is a mold clamping device in which a movable plate having a temperature control circuit is supported on a guide pedestal so as to run freely.

In addition to the fixed platen (fixed platen) and movable platen (movable platen), the rear platen (pressure platen) and tie bar are also equipped with a temperature control circuit so that the temperature can be adjusted. Some have solved the obstruction of parallelism due to temperature non-uniformity in the entire mold clamping device that tends to occur when the temperature of the mold is adjusted.
JP 2006-256034 A JP 2006-221980 A

  In the conventional mold clamping device described in Patent Document 1, the thermal expansion of the plate body due to heat transfer from the mold is generated evenly from the center of the plate body by supporting the both sides of the plate body. The thermal deformation resulting from the difference is reduced, and the mold closing accuracy of the mold is maintained even when used for a long period of time, so that the mold is prevented from being bitten and molding defects are also reduced. The deformation caused by the clamping force also appears symmetrically with respect to the center of the plate body without being constrained by the tie bar in the movable platen, so that distortion caused by the clamping force is also suppressed, causing mutual displacement between molds. Both thermal deformation and deformation due to external force can be prevented at the same time. In addition, the temperature control circuit can control the heat transfer from the mold by adjusting the temperature of the fixed platen and the movable platen. There is an advantage that the deviation can be adjusted.

  However, the adjustment of the misalignment between the molds there is based on the control of the thermal deformation of the plate body by controlling the temperature of either or both of the fixed plate and the movable plate. Therefore, the adjustment cannot be easily performed depending on the misalignment direction. There is. In the conventional apparatus described in the cited document 2, the temperature of the tie bar is also controlled to prevent the axis deviation of the upper and lower tie bars. However, the thermal expansion of the board is not restricted by the tie bar, and the guide pedestal runs on both sides. It is difficult to adopt for a freely supported movable plate, and the thermal expansion of the tie bar is larger in the axial direction than in the radial direction, and the tie bar extension force acts as a pressing force at the four corners of the fixed plate. As a result, distortion and bending occur in the upper and lower sides of the board, and the problem arises that the perpendicularity of the fixed board is impaired.

  The object of the present invention is to make it possible to control the temperature of a pedestal supporting them in addition to a fixed plate or a movable plate with a built-in temperature control circuit. A mold for an injection molding machine that can control the thermal expansion direction of the fixed and movable platens in relation to the guide base and easily adjust the misalignment between the molds attached to the platen. It is to provide a fastening device.

  This invention according to the above object comprises a fixed plate and a pressure plate that are connected to each other on a machine base by connecting with a tie bar, and a movable plate provided so as to be able to move forward and backward between the two boards. The vertical center of both sides of the fixed platen is fixed to the support pillars erected on the operation side and the non-operation side of the platen base, and installed vertically on the fixed platen base, while the movable platen is parallel to the operation side and the non-operation side. In a mold clamping device that is supported by a guide pedestal installed on the pedestal so that it can run freely without being restrained by a tie bar, and a temperature control circuit for a heat medium is provided in the stationary platen and the movable platen, There is a temperature control circuit through which the medium flows, and the temperature control circuit for each temperature control circuit can adjust the deviation of the mold center between the molds due to the difference in thermal expansion by the temperature control of the heat medium. It is said to be connected to.

  In addition, the fixed platen base has a concave surface with a pair of support pillars standing on both ends of the base plate, and both support pillars are at a height that supports the center of the side surface of the fixed plate at the upper end and are positioned on the operation side. The column thickness (lateral direction) of the supporting column is formed to be thicker than the column thickness (lateral direction) of the support column located on the counter-operation side.

  The guide pedestal is configured such that the operation side is lower than the lower tie bar position, and the counter-operation side is thicker than the operation side (lateral direction) and is set higher up to the upper tie bar position. The guide means includes a linear guide rail laid on the upper surface of the guide base on the operation side and the non-operation side, a linear guide member slidably fitted to the linear guide rail, and the linear guide member attached to the lower surface. It also consists of a running member.

  The movable platen has a vertically long support member on the operation side and the non-operation side platen body side, the operation side support member is a thick plate and is fixed by placing the lower end on the traveling member and fixing it. The support member on the side is a thin plate, the upper end side surface is attached to the travel member, and the support member is supported on the guide base so as to travel freely. The mold clamping machine includes a tie bar inserted into the four corners and a mold mounting board that is attached to the front surface of the mold clamping machine by connecting a central portion thereof. The mold mounting board is connected to the operation-side support member and the counter-operation. The support member on the side is supported so as to be able to run on the guide base.

  In the above configuration, in addition to the fixed platen and the movable platen, the temperature control circuit is also provided for the support column and the guide pedestal that supports each platen, so that the support column and the guide pedestal are controlled by controlling the temperature of the heat medium flowing therethrough. Is thermally expanded in the vertical direction on the basis of the fixed lower end, and thereby the vertical shift between the mold axes of the fixed mold and the movable mold attached to the board can be adjusted.

  In addition, by changing the column thickness (lateral direction) of both support columns of the fixed platen base and the plate thickness of the support members on both sides of the movable platen, a difference was made in the rigidity of the support columns and support members on the operation side and the non-operation side. Due to the difference in rigidity, thermal expansion in the board body occurs in the lateral direction based on the rigid side, whereby the horizontal displacement of the mold axis between the molds can be adjusted.

  In the figure, reference numeral 1 denotes a stationary platen, 2 denotes a pressure receiving plate, and the four corners of the plate body having a square plate surface are connected to each other by tie bars 3 and 3 and are erected on the machine base 4. Reference numeral 5 denotes a movable plate provided between the fixed platen 1 and the pressure platen 2 so as to be able to advance and retreat. The mold clamping plate 51 has four corners inserted into the tie bars 3 and 3 and the die mounting plate 52 in front of the mold clamping plate 51. A toggle mechanism 6 for clamping the mold is provided between the mold clamping plate 51 and the pressure receiving plate 2 by connecting toggle links 61 and 61 to the upper and lower positions of the pressure receiving plate 2 and the mold clamping plate 51, respectively. .

  The mold clamping plate 51 and the mold mounting plate 52 are integrally connected at the center by a mold clamping force transmission member 53, and the tie bar insertion holes at the four corners of the mold mounting plate 52 are larger than the diameter of the tie bar 3. It is formed in a diameter, and a thermal expansion gap 3 a is formed around the tie bar 3. Due to this thermal expansion gap 3 a, the mold mounting plate 52 is thermally expanded without being restrained by the tie bar 3.

  As shown in FIG. 3, the fixed platen 1 is vertically supported by a fixed platen base 7 installed on the machine base. The fixed platen base 7 has a plate thickness that is at least the same as that of the fixed platen 1 and is longer than the horizontal width of the fixed platen, and a pair of support columns 72 and 72 'standing on both ends of the platen. Of things. The heights of both support columns 72 and 72 'are set to a height that supports the center of the fixed platen 1 at the upper end, and the column thickness (lateral direction) of the support column 72 located on the operation side (left side in the figure). This is set to be thicker than the column thickness (lateral direction) of the support column 72 ′ located on the counter-operation side (right side). The fixed platen 1 has support portions 12 and 12 'projecting from the center on both sides, placed on the upper ends of both support columns 72 and 72', and fixed to the support columns 72 and 72 'by bolts 54 and 54'. In addition, an expansion gap is provided between the inside of the support column and the seat plate.

  Further, guide pedestals 8, 8 'of the movable platen 5 are installed in parallel to the longitudinal direction of the upper surface of the machine base so as to be perpendicular to the seat plate on both inner sides of the operation side and the non-operation side of the seat plate 71. . The height of the guide pedestal 8 on the operation side is set lower than the position of the lower tie bar, and the guide pedestal 8 'on the non-operation side is thicker than the operation side, and on the quadrilateral frame of the same width. The upper pedestal 8 ″ is erected integrally and is set high up to the position of the upper tie bar.

  Linear linear guide rails 81 and 81 'are laid on the upper surface of the operation-side guide base 8 and the upper surface of the operation-side upper base 8' '. The linear guide rails 81 and 81' are provided with a traveling member 82. , 82 ′ are slidably provided by fitting a pair of linear guide members 83, 83 ′ attached to the front and back surfaces of the guide rail to the guide rail.

  The mold clamping plate 51 and the mold mounting plate 52 of the movable platen 5 are formed of square plate bodies, and a gap is provided between the two plates by the mold clamping force transmitting member 53 interposed in the center. Even if the mold clamping machine 51 is distorted by the mold clamping force due to the gap and the upper and lower parts of the mold clamping machine 51 warp toward the mold mounting board, the warpage does not reach the mold mounting board 52. The dimension of the gap can be arbitrarily set by changing the thickness of the mold clamping force transmission member 53.

  Further, support members 54, 54 'made of vertically long plates are attached to the side surfaces of the mold mounting plate 52 on the operation side and the counter-operation side by bolts. The support member 54 on the operation side is a thick plate, and the lower end is placed on the traveling member 82 and fixed by bolts. Further, the support member 54 'on the counter-operation side is a thin plate, and a traveling member 82' is attached to the upper end side surface with a bolt. As a result, the mold mounting plate 52 is supported by the guide bases 8 and 8 'via the upper and lower traveling members 82 and 82' so that it can run freely, so that no load is applied to the tie bars 3 and 3.

  The pressure receiving plate 2 is movably mounted on a base plate 9 and installed on a machine base. At the center of the pressure receiving plate 2, a toggle driving screw shaft 62 located at the center between the toggle links of the toggle mechanism 6 is rotatably inserted horizontally and supported. The links 61 and 61 are screwed together so that a cross head 64 that bends and extends through the operating link 63 is moved forward and backward by the rotation of the screw shaft 62 by an electric servo motor (not shown).

  Inside the fixed platen 1 and the mold mounting plate 52, both support pillars 72 and 72 'of the fixed platen base 7, and the operation-side guide base 8 and the non-operating side upper base 82 "are for temperature control. Temperature control circuits 1a, 52a, 72a, 72a ', 8a, 8a' are provided, respectively, and the temperature of each of the above-mentioned parts that support the board and the board is adjusted by a heat medium that flows through these flow paths. The shift of the mutual center position (hereinafter referred to as the mold axis) of the fixed mold 10a attached to the fixed board 1 and the fixed mold 10b attached to the mold mounting board 52 can be adjusted.

  The temperature control circuits 1a and 52a of the fixed platen 1 and the mold mounting plate 52 are arranged in a U-shape parallel to the upper and lower sides of the center of the plate body from the upper edge and the lower edge of the plate body, and the temperature adjustment circuit 1a. Is connected to the temperature controller A1 and the temperature control circuit 52a is connected to the temperature controller A2 separately.

  The temperature control circuits 7a, 72a 'of the support column 72, 72' are arranged in a U-shape vertically from the outside of the column body to the inside of the column body, and are connected to the temperature controller B1, and the guide base 8 and the upper base 8 The temperature control circuits 8a and 8a 'are arranged in a U shape from the inner edge of the seat body to the outer edge of the seat body, and are individually connected to the temperature controller B2.

  In such a mold clamping device, the load of the movable platen 5 received by the tie bars 3 and 3 is reduced by the support by the upper and lower guide portions on both sides of the die mounting plate 52, so that the tie bars 3 and 3 are bent by the load. It is difficult to cause a height displacement due to the sinking of the mold mounting plate 52 downward. Further, since the mold mounting board 52 is supported on the upper and lower sides of both sides of the board body and the tie bar 3 is not restrained by the thermal expansion gaps 3a at the four corners of the board body, the heat of the board body due to heat transfer from the mold. Expansion occurs in four directions open from the center of the board, and warping of the board due to uneven thermal expansion due to tie bar restraint is prevented.

  In the fixed platen 1 as well, the vertical center portions of both the operation side and the non-operation side of the platen body are fixed to the support pillars 72 and 72 on both sides of the fixed platen base 7 and installed vertically on the machine base 4. As a result, the thermal expansion of the plate body due to heat transfer from the mold occurs in the four directions open from the center of the plate body, and therefore due to non-uniform thermal expansion that occurs when the lower end is constrained to the machine base. The warping of the board is prevented.

  In addition, a fine (one to several microns) misalignment between the fixed mold 10a and the movable mold 10b due to a difference in thermal expansion after the mold shafts are mounted on the two plate bodies together can be caused by the fixed plate 1 and the mold mounting plate 52. The temperature control circuits 1a and 52a included in the above and the temperature control circuits 72a, 72a ′, 8a, and 8a ′ included in the respective portions that support the respective panel bodies can be controlled and adjusted.

  When the temperature of the platen of the fixed platen 1 is raised by increasing the medium temperature, the column widths of the support column 72 on the operation side and the support column 72 'on the non-operation side of the fixed platen base 7 supporting the fixed platen 1 are increased. However, due to the difference in rigidity due to the difference in the column width, the resistance against thermal expansion acts more on the operating side than on the non-operating side. Therefore, the thermal expansion in the horizontal direction in the panel is based on the supporting column 72 on the operating side. As shown in FIG. The extension force due to thermal expansion at this time is absorbed by the deflection of the support column 72 '. In addition, the thermal expansion in the vertical direction occurs evenly because the upper and lower plate bodies are under the same conditions. As a result, the center axis of the panel body is not shifted vertically but shifted horizontally to the counter-operation side.

  Further, in the mold mounting board 52, the operation side support member 54 is thicker and more rigid than the counter operation side support member 54 ', and the support point of the board body by the support member 54 is also at a low position close to the machine base. On the other hand, the support point on the counter-operation side is the upper end of the upper pedestal 8 ″ away from the machine base, so that the stress due to thermal expansion in the horizontal direction is applied to the support point on the counter-operation side when the temperature of the panel is raised. The upper pedestal 8 ″ is inclined at the upper end portion and is inclined outward. As a result, the board body expands from the operation side to the non-operation side, and the extension force is absorbed by the inclination due to the bending of the upper base 8 ″. As a result, the axis of the disc body does not shift up and down but shifts horizontally toward the non-operation side.

  When the temperature of the support columns 72 and 72 ′ and the guide bases 8 and 8 ′ is increased by increasing the medium temperature, the support columns 72 and 72 ′ are thermally expanded upward based on the machine base 4. Due to the upward expansion due to the thermal expansion, the fixed platen 1 supported by the support columns 72 and 72 ′ and the movable platen supported by the guide bases 8 and 8 ′ (8 ″) via the die mounting plate 52. 5 is lifted by the amount of extension, and the axis of the plate body is shifted upward, whereby the fixed platen 1 and the die mounting platen are controlled by temperature control of either the support columns 72, 72 'or the guide bases 8, 8'. Since the relative position of 52 can be shifted up and down, it is also possible to adjust the vertical misalignment between the fixed mold 10a and the movable mold 10b after the mold axes are aligned and attached to the two plate bodies.

  Therefore, the heat medium flowing through the temperature control circuits 1a, 52a, 72a, 72a ', 8a, 8a' respectively provided in the fixed platen 1, the mold mounting plate 52, the support columns 72, 72 'and the guide bases 8, 8' are provided. With temperature control, it is possible to adjust the deviation of the mold axis in the horizontal, vertical and diagonal directions of the fixed mold 10a and the movable mold 10b attached to the fixed plate 1 and the mold mounting plate 52 in units of μm.

The temperature of the heat medium for adjusting the misalignment is calculated from the coefficient of thermal expansion at each temperature based on the coefficient of thermal expansion and the material dimensions (length) of the metal material used as the component material of the mold clamping device. Since this is possible, it is only necessary to set the temperature by measuring the misalignment between the mold axes of the dies.
For example, constituent material: ductile cast iron
Thermal expansion coefficient α = 11.88 × 10 ⁻⁶ [/ ° C.]
Material size: 200 [mm] Expansion size: 1 ° C. = 2.4 [μm]
Therefore, the misalignment between the fixed mold 10a and the movable mold 10b after the mold shafts are mounted on the two plate bodies is extremely easy with the temperature control of the heat medium by the temperature controller regardless of the misalignment direction. It is possible to correct and adjust with high accuracy.

  In the above embodiment, the movable platen 5 is constituted by the mold clamping platen 51 and the die mounting platen 52. However, the movable platen 5 can move the guide means even in the case of a single platen body as before. If it is installed on the operation side and the non-operation side on both sides of the board, and the guide means on both sides are arranged with a difference in height on both sides of the board, thermal deformation due to heat transfer is prevented. Therefore, the present invention is not limited to the mold clamping device of the above embodiment. Although the toggle mechanism is described as the mold clamping means, the same effect can be obtained with the mold clamping means using a hydraulic cylinder. Therefore, the present invention is not limited to the toggle mechanism for the mold clamping means.

It is a top view of the mold clamping apparatus of the injection molding machine which concerns on this invention. It is a side view same as the above. It is a front view by the side of a stationary platen similarly. It is AA sectional drawing of FIG. It is the perspective view which showed schematically the temperature control circuit of a stationary base and a guide base.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed platen 1a Temperature control circuit 3 Tie bar 3a Thermal expansion gap 4 Machine stand 5 Movable platen 7 Fixed platen base 7,7 'Support pillar 8,8' Guide base 8 "Upper base 8a, 8a 'Temperature control circuit 51 Mold clamping board 52 type mounting board 52a type mounting board temperature control circuit 54, 54 'type mounting base support member 72, 72' support column 72, 72a temperature control circuit 81, 81 'linear guide rail 82, 82' travel member 83, 83 ′ Linear guide member

Claims (6)

A fixed platen and pressure platen connected to each other by a tie bar and a movable platen that can be moved forward and backward between the two plates are provided, and the fixed plate is opposite to the operation side of the fixed platen base on the machinen base. The vertical center of both sides of the fixed platen is fixed to the support column standing on the operation side, and installed vertically on the fixed platen base, while the movable platen runs on the guide base installed in parallel on the operation side and the non-operation side. In a mold clamping device that supports freely and has a temperature control circuit for the heat medium in the fixed platen and movable platen,
A temperature control circuit through which the heat medium flows is provided between the support column and the guide base, and the temperature control circuit can adjust the deviation of the mold axis between the molds by the thermal expansion difference by the temperature control of the heat medium. A mold clamping device for an injection molding machine, wherein each temperature control circuit is connected to a temperature controller.   The fixed platen base has a concave surface with a pair of support columns standing on both ends of the seat plate, and both support columns are positioned at the operation side at a height that supports the center of the side surface of the fixed plate at the upper end. The mold clamping device for an injection molding machine according to claim 1, wherein the column thickness (lateral direction) of the support column is formed to be thicker than the column thickness (lateral direction) of the support column located on the non-operation side.   2. The guide pedestal is configured such that an operation side is lower than a lower tie bar position, and a counter-operation side is formed higher in thickness (lateral direction) than an operation side to be higher up to an upper tie bar position. Clamping device for injection molding machine.   The guide means of the movable platen includes a linear guide rail laid on the upper surface of the guide base on the operation side and the counter-operation side, a linear guide member slidably fitted to the linear guide rail, and the linear guide member 4. The mold clamping device for an injection molding machine according to claim 1, further comprising a traveling member attached to the lower surface.   The movable platen has a vertically long support member on the operation side and the non-operation side platen body side, the operation side support member is a thick plate and is fixed by placing the lower end on the traveling member and fixing it. 5. The injection molding machine according to claim 1, wherein the supporting member on the side is a thin plate and has an upper end side surface attached to the traveling member, and is supported on the guide base so as to be able to travel freely. Mold clamping device.   The movable platen includes a mold clamping plate in which the tie bars are inserted into the four corners, and a mold mounting plate that is attached by connecting a central portion to the front surface of the mold clamping plate, and the mold mounting plate is supported on the operation side. 6. A mold clamping device for an injection molding machine according to claim 5, wherein said mold clamping device is supported on said guide base so as to be freely movable by said support member on said counter-operation side.

Images