JP4417082B2 - Vacuum forming equipment - Google Patents

Description

  The present invention relates to a vacuum forming apparatus that forms a sheet using a pressure difference generated on the front and back surfaces of a sheet by creating a vacuum state between the sheet and a molding die, and in particular, forms a sheet by pressing a pressing mechanism. The present invention relates to an auxiliary vacuum forming apparatus.

  In the conventional vacuum forming apparatus, the heat-softened sheet is arranged along the surface of the molding die for easy processing, and the lower table and the upper table are moved relative to each other by the moving means, A hole for vacuuming formed in the molding die by holding the periphery of the sheet between the lower open end of the rectangular frame member provided on the upper table and the lower table on which the molding die is placed. By evacuating, the sheet is brought into close contact with the molding die, and the sheet is molded into the shape of the molding die.

  However, when the sheet is formed by vacuum drawing, the sheet does not adhere to the shape part such as the fine groove of the molding die, and the excess part is urged to the molding die. In other words, the sheet may not be completely molded into the shape of the molding die.

Therefore, the upper table is provided with a pressing mechanism with a shape aligned with a part that is difficult to adhere to the molding die, such as fine grooves, and the sheet is pressed from the outside to the molding die side while the sheet is stretched by the pressing mechanism during molding. It has been proposed to assist the forming of the sheet by bringing the sheet into close contact with the molding die (see, for example, Patent Document 1).
JP 2000-343593 (page 1-4, FIG. 1)

  By the way, in order to assist the forming of the sheet using the pressing mechanism in this way, the pressing mechanism having a shape aligned with the molding die needs to press the sheet from the outside at the position of the molding die corresponding to the shape. There is. Since the pressing mechanism is provided on the upper table and the molding die is provided on the lower table, the upper table and the lower table must be positioned so that the pressing mechanism and the molding die are aligned during molding. For this reason, of the two tables that move in the direction of relative approach during molding, both the table provided with the moving means or one of the tables is a lifting guide post for stabilizing the movement of the table in addition to the moving means. Is provided along the moving direction on the back side of the table.

  However, since the above-described lifting guide post is for assisting and stabilizing the table movement, the table is not in a predetermined position at the time of molding due to vibration accompanying the movement of the table or play of equipment. If the table is moved to a different position and a positional shift occurs between the two tables that are relatively close to each other, the molding die and the pressing mechanism may not be aligned. For this reason, in order to accurately assist the molding by the pressing mechanism at the time of molding, a troublesome work process in which the operator visually adjusts the alignment between the upper table and the lower table is necessary.

  Accordingly, an object of the present invention is to provide a vacuum forming apparatus capable of easily aligning an upper table and a lower table when forming a sheet by vacuum drawing.

In order to solve the above-described problem, the vacuum forming apparatus according to claim 1 includes a molding die in which a plurality of vacuuming holes are formed on a die surface, and a lower table on which the molding die is placed. And a holding mechanism that temporarily holds the sheet softened to be molded by the molding die above the molding die, and a rectangular shape that is disposed above the lower table with the sheet interposed therebetween and has an open lower end. An upper table having a frame member, and at the time of forming the sheet, the lower table and the upper table are moved relatively to each other in a direction to bring the sheet along the surface of the molding die, and the periphery of the sheet A molding drive mechanism for holding the sheet in close contact with the surface of the molding die by holding the sheet member between the lower end open end of the frame member and the lower table, and performing vacuuming through the hole for vacuuming; frame Provided inside the timber, the a vacuum forming apparatus and a pressing mechanism for pressing the molding die side the seat from the outside to remove wrinkles generated in the sheet, the edges of the lower table A plurality of columnar lower guide posts, and a plurality of columnar upper guide posts corresponding to the lower guide posts at the edge of the upper table are formed at the upper end surface of the lower guide post when the sheet is formed. And the lower guide post as a correcting means for correcting a relative positional shift in the direction perpendicular to the vertical movement direction of the upper table and the lower table. The upper guide post has a protruding portion having a conical shape or a truncated cone shape, the diameter of which gradually decreases as at least a part thereof is directed upward. A fitting hole into which the protrusion can be fitted is formed in the lower end surface, or an inverted cone whose diameter dimension gradually decreases as the lower end surface of the upper guide post moves downward. In the lower guide post and the upper guide post, the protrusions having a shape or an inverted frustoconical shape are respectively formed with fitting holes into which the protrusions can be fitted on the upper end surface of the lower guide post. A groove is formed along the vertical direction on the outer peripheral surface of the portion where the fitting hole is formed .

A vacuum forming apparatus according to a second aspect is the vacuum forming apparatus according to the first aspect , wherein an open end portion of each fitting hole is provided with a diameter-expanding portion for facilitating reception of the protrusion. It is characterized by being.

The vacuum forming apparatus according to claim 3 is the vacuum forming apparatus according to claim 1 or 2 , wherein the lower guide post has the upper end surface placed on the lower table, and the molding die is placed thereon. It is characterized by being the same height as the upper end surface.

In the vacuum forming apparatus according to claim 1, when the forming drive mechanism moves the upper table and the lower table relatively to bring them closer to each other in order to vacuum form the sheet, the lower table When the position is deviated or the position of the upper table is deviated with respect to the lower table, the position deviations are corrected by the correcting means. As a result, since the position of the pressing mechanism with respect to the molding die is also a preset normal position, the pressing mechanism can press the place to be pressed on the sheet, and the sheet may be wrinkled. Absent.
Further, when the two tables approach each other at the time of forming the sheet, and a plurality of guide posts provided on both tables come into contact with each other, a projection that exhibits a conical shape or a truncated cone shape (inverted cone shape or inverted truncated cone shape) The misalignment of both tables can be corrected by fitting the fitting holes with the fitting holes.
Further, when the protrusion is fitted into the fitting hole, a groove is formed in the peripheral wall portion even if the load is concentrated on the portion of the peripheral wall portion that defines the fitting hole that is in contact with the protruding portion. Since the load is distributed in the direction along the groove, the peripheral wall portion is restrained from being bent, so that the positional deviation between the two tables can be corrected more reliably.

In the vacuum forming apparatus according to the second aspect , it is possible to easily receive the protruding portion by the fitting hole when both tables approaching each other at the time of forming are displaced.

In the vacuum forming apparatus according to the third aspect , it is possible to reduce the possibility that both guide posts obstruct work such as maintenance of the vacuum forming apparatus, and to increase the work efficiency.

A molding die in which a plurality of evacuation holes are formed on the die surface, a lower table on which the molding die is placed, and a heat-softened sheet to be molded by the molding die. A holding mechanism that temporarily holds above the mold, an upper table that is disposed above the lower table with the sheet interposed therebetween, and that has a rectangular frame member with an open lower end; and the lower table and the upper table when the sheet is molded The table is moved relative to each other in the direction in which the tables are brought closer to each other so that the sheet follows the surface of the molding die, and the periphery of the sheet is sandwiched between the lower end open end of the frame member and the lower table, and vacuum drawing is performed. And a molding drive mechanism for vacuuming the sheet through the hole for tight contact with the surface of the molding die, and an inner side of the frame member for removing wrinkles generated on the sheet. And a pressing mechanism that presses the mold from the outside toward the molding die side, and corrects a relative positional deviation in the direction perpendicular to the vertical movement direction of the upper table and the lower table. In addition to the configuration provided with the means, the correcting means is formed on the lower end open end portion of the frame member and formed on the upper end surface of the lower table, and the vertical section along the frame member has an inverted trapezoidal shape. The convex portion can be fitted with a concave portion having an inverted trapezoidal cross section, and the convex portion is formed on at least two adjacent vertical walls of the four vertical walls constituting the frame member. If the concave portion is formed at least at two locations corresponding to the convex portion, the correction means provided at at least two locations have a right angle relationship with each other, and the lower table and the upper table are relatively Move each other Upon closer convex portion provided at a lower end open end face of the frame member of the upper table, fitted in a recess provided in the lower table. In this case, both the convex part and the concave part have an inverted trapezoidal shape and have inclined surfaces on both sides of the convex part and the concave part, so the positions of the lower table and the upper table are shifted from each other. Even if the lower tip of the convex part hits and catches on the oblique side surface of the concave part, if the lower table and the upper table are brought closer together, the lower tip part of the convex part and the oblique side surface of the concave part slide against each other, thereby causing the convex part And the recess fit completely. Thereby, the lower table and the upper table are accurately positioned.
Further, in addition to the above-described configuration, the correcting means is formed at the lower end open end portion of the frame member and a longitudinal section along the frame member is formed at a trapezoidal concave portion and an upper end surface of the lower table. The concave portion can be fitted into a concave portion and has a trapezoidal convex section, and the concave portion is formed on the lower end surface of at least two adjacent vertical walls among the four vertical walls constituting the frame member, Assuming that the convex portions are also formed in at least two locations corresponding to the concave portions, the concave portions formed in the lower end surface of the vertical wall and having a trapezoidal shape even when both tables approaching each other at the time of molding are displaced. The convex portion provided on the lower table is slip-fitted with the oblique side surface of the concave portion and the upper end of the convex portion being in contact with each other, thereby correcting the positional deviation between the two tables.
Further, in addition to the above-described configuration, the correcting means is formed on the lower end open end portion of the frame member, and the longitudinal section along the frame member is formed on the convex portion having an arc shape and the upper end surface of the lower table. The convex part can be fitted and has a concave part with an arc-shaped vertical cross section, and the convex part is formed on the lower end surface of at least two adjacent vertical walls among the four vertical walls constituting the frame member. Assuming that the concave portion is also formed in at least two locations corresponding to the convex portion, the convex portion having an arc shape provided on the lower end surface of the vertical wall at the time of molding has an arc shape provided on the lower table. Fits into the recess. Even when the positions of the lower table and the upper table are shifted from each other during fitting and the opening end of the recess hits the arcuate surface of the protrusion, if the lower table and the upper table are brought closer together, the opening end of the recess The convex part and the concave part are completely fitted by sliding while the part and the arcuate surface of the convex part are in contact with each other. Thereby, the lower table and the upper table are accurately positioned.
In addition to the above-described configuration, the correcting means is formed on the lower end open end portion of the frame member, and a longitudinal section along the frame member is formed in an arc-shaped recess and an upper end surface of the lower table. The convex portion is a convex portion having a circular cross section that can be fitted, and the concave portion is formed on a lower end surface of at least two adjacent vertical walls among the four vertical walls constituting the frame member, and the convex portion If at least two locations are formed corresponding to the recesses, even if both tables approaching each other at the time of molding are misaligned, a recess having an arc shape formed on the lower end surface of the vertical wall, The convex portion formed on the upper end surface of the table and having an arc shape is slip-fitted with the opening end portion of the concave portion and the arc-shaped surface of the convex portion coming into contact with each other, thereby correcting the positional deviation between both tables. Can do.

  According to the vacuum forming apparatus of the present invention, when the forming drive mechanism works to vacuum form the sheet, even if the upper table and the lower table are misaligned, the misalignment of both tables is corrected by the correcting means. As a result, since the pressing mechanism and the molding die are positioned so as to be aligned with each other, it is possible to accurately assist the molding of the sheet by the pressing mechanism without relying on human hands. It can be formed into a shape.

  The present invention will be described in detail with reference to the embodiment shown in FIGS.

  As shown in FIG. 1, the vacuum forming apparatus 10 according to the present embodiment includes a lower table 11 that can move up and down and an upper table 12 that can move up and down. In FIG. 1, x, y, and z arrows that are orthogonal to each other are shown, and the arrow direction of y is on the top. Hereinafter, the respective directions are represented by symbols x, y, and z as necessary. Moreover, the arrow of FIG. 2 mentioned later and each symbol of x, y, z respond | correspond to FIG.

  The lower table 11 is supported by a drive shaft 13 connected to a lower table elevating cylinder (not shown) which is a part of the molding drive mechanism so as to be movable up and down. The lower table 11 is provided with lower lifting guide posts 14 at four locations around the drive shaft 13 for stabilizing the vertical movement of the lower table.

  The upper table 12 is provided with a drive shaft 15 connected to an upper table lifting cylinder (not shown) which is a part of the molding drive mechanism, and a pair of upper lifting guides for stabilizing the vertical movement of the upper table 12. Posts 16 are provided at four locations around the drive shaft 15.

  The lower table 11 is provided with a mounting table 17 on a surface facing the upper table 12, and a molding die 18 is mounted thereon. The molding die 18 is formed with a plurality of holes 19 which are part of the molding drive mechanism and are used for evacuation. One end of each hole 19 is opened to the surface 18a of the molding die 18 to form an opening 20, and the other end is connected to a vacuum device (not shown) such as a vacuum pump or a vacuum tank.

  A sheet 22 temporarily held by the holding mechanism 21 is disposed above the lower table 11. The sheet 22 is formed as a sheet for an instrument panel, for example. The holding mechanism 21 temporarily holds the sheet 22 heated and softened by a heating device (not shown) above the lower table 11 in order to facilitate molding. At the time of molding, the sheet 22 is disposed along the surface 18 a of the molding die 18.

  The upper table 12 is formed with a frame member 23 for holding the sheet 22 between the lower table 11 during molding. In the frame member 23, four flat vertical walls 24 are assembled in a rectangular shape, and a lower part thereof is a lower end open end of the frame member 23. At the time of molding, the lower end surface 24a of each vertical wall 24 contacts the upper end surface 17a of the mounting table 17 of the lower table 11 with the sheet 22 interposed therebetween. The lower end surface 24a of the four vertical walls 24 and the upper end surface 17a in contact with the lower end surface 24a are provided with a concave portion 27 and a convex portion 26 each having a trapezoidal cross section along the vertical wall 24 as correction means. ing.

  FIG. 2 shows an enlarged view of one of a pair of convex portions 26 and concave portions 27 provided at four locations. In the convex part 26 and the concave part 27 of FIG. 2, the above-mentioned longitudinal section is a section along a plane defined by the x and y directions. The convex portion 26 is provided at the edge portion of the upper end surface 17 a of the mounting table 17, and is formed with substantially the same thickness as the vertical wall 24 of the frame member 23. The recessed part 27 is provided in the lower end surface 24a of the vertical wall 24, and the convex part 26 can be fitted therein. When the lower end surface 24a of the vertical wall 24 and the upper end surface 17a of the mounting table 17 are in contact with each other with the sheet 22 interposed therebetween, the positions of the lower table 11 and the upper table 12 are displaced along the x direction, and the convexity Even if the upper tip 26a of the portion 26 is in contact with and hooked to the oblique side portion 27a of the recess 27 with the sheet 22 in between, if the lower table 11 and the upper table 12 are brought closer to each other, the upper tip 26a of the projection 26 The convex portion 26 is completely fitted into the concave portion 27 by sliding with the oblique side portion 27a of the concave portion 27 with the sheet 22 interposed therebetween. The convex portion 26 and the concave portion 27 are set so as to be completely fitted when the positions of the lower table 11 and the upper table 12 coincide with each other, and the convex portions 26 provided at four positions are in the concave portion 27. When completely fitted, the mutual displacement between the lower table 11 and the upper table 12 is corrected.

  As shown in FIG. 1, the upper table 12 is provided with a plurality of pressing mechanisms 28. The pressing mechanism 28 includes a pressing operation unit 28a attached to the tip of the rod 28b, a piston 28c attached to the multiple ends of the rod 28b, and a cylinder 28d for driving the piston 28c. The pressing mechanism 28 is driven by the piston 28c and the cylinder 28d so as to move the pressing operation unit 28a via the rod 28b. The pressing mechanism 28 is provided at a position facing a deep groove or a fine step portion on the surface 18a of the molding die 18, and when the sheet 22 is formed, the sheet 22 is pressed by the pressing operation portion 28a with a deep groove or a fine step on the surface 18a. It is driven to press from the outside so as to urge the portion or the like, thereby assisting the forming of the sheet 22. The pressing mechanism 28 is configured so that when the lower table 11 and the upper table 12 are positioned at predetermined positions, the pressing operation portion 28a can press a deep groove or a fine step portion on the surface 18a of the molding die 18. Has been placed.

  Next, the operation of the vacuum forming apparatus 10 will be described.

  As described above, the sheet 22 heated and softened by a heating device (not shown) is temporarily held by the holding mechanism 21 and disposed above the lower table 11. At the time of molding, as shown in FIG. 3, the molding drive mechanism works to raise the lower table 11 and lower the upper table 12, whereby the sheet 22 is arranged along the surface 18 a of the molding die 18, The periphery is sandwiched between the lower end surfaces 24 a of the four vertical walls 24 of the frame member 23 and the upper end surface 17 a of the mounting table 17. At this time, since the vacuum is not applied, the sheet 22 is not in close contact with the molding die 18 and the pressing mechanism 28 is not driven.

  At this time, the lower end surface 24a and the upper end surface 17a are respectively formed with a convex portion 26 and a concave portion 27 as correction means, so that the lower table 11 and the upper table 12 are pressed by the pressing mechanism 28 of the molding die 18. It is positioned so that the position of can be pressed. That is, since the frame member 23 is composed of four vertical walls 24 arranged in a rectangular shape, the adjacent vertical walls 24 are in a perpendicular relationship with each other, and therefore, 2 provided on the adjacent vertical walls 24. The two recesses 27 are also in a positional relationship perpendicular to each other. In addition, as described above, the pair of convex portions 26 and concave portions 27 is a direction (x direction or z direction) along the vertical wall 24 in a direction along a plane defined by the x and z directions, respectively. The upper end 26a of the convex portion 26 and the oblique side portion 27a of the concave portion 27 can be corrected by slipping and fitting with each other with the sheet 22 interposed therebetween. Therefore, the positional deviation between the lower table 11 and the upper table 12 in the direction along the plane defined by the x and z directions is caused by the concave portions 27 and the four convex portions 26 provided on the four vertical walls 24, respectively. Therefore, the lower table 11 and the upper table 12 are positioned so that the pressing mechanism 28 and the molding die 18 are aligned with each other.

  Furthermore, a vacuum drive (not shown) is operated to make a vacuum state between the surface 18a of the molding die 18 and the sheet 22 by operating the molding drive mechanism. As a result, a vacuum is drawn from the opening 20 formed in the surface 18a of the molding die 18 through each vacuuming hole 19, so that the heat-softened sheet 22 is in close contact with the surface 18a of the molding die 18. To do.

  When the sheet 22 is formed by vacuum drawing, the sheet 22 does not come into close contact with the surface 18a of the molding die 18 at the shape portion such as a deep groove or a fine step on the surface 18a of the molding die 18. Since the surplus portion is urged by the molding die 18, it tends to become a wrinkle. The pressing mechanism 28 urges the sheet 22 by dispersing the excess wrinkles by pressing the surface 18a while extending the wrinkles from the outside while the pressing operation portion 28a tends to become the wrinkles of the sheet 22 from the outside. 22 is in close contact with the surface 18 a of the molding die 18. At this time, the pressing mechanism 28 and the molding die 18 are positioned so as to be aligned by the convex portion 26 and the concave portion 27, so that the molding of the sheet 22 is assisted at an accurate position.

  As described above, in the vacuum forming apparatus 10 according to the first embodiment, when the forming drive mechanism works during forming and the sheet 22 is vacuum formed, the pressing mechanism 28 is formed by the convex portion 26 and the concave portion 27 so that the pressing mechanism 28 has a predetermined shape. The lower table 11 and the upper table 12 are positioned so that the position can be pressed. For this reason, when the vacuum forming is performed, it is not necessary for the operator to adjust the position of the lower table 11 and the upper table 12 by visual observation, so that the working efficiency can be increased and the molding cost of the sheet 22 can be reduced. can do.

  Further, since the lower table 11 and the upper table 12 are positioned by fitting the convex portion 26 and the concave portion 27 provided at a predetermined position, the operator manually adjusts the alignment. In comparison, the quality of the molding applied to the sheet 22 can be stabilized.

  Therefore, in the vacuum forming apparatus 10 according to the first embodiment, since the lower table 11 and the upper table 12 are positioned when the sheet 22 is vacuum formed, the forming assistance by the pressing mechanism 28 is accurately performed without relying on human hands. The sheet 22 can be reliably formed in the shape of the molding die 18.

  Next, a modification of the first embodiment will be described. The characteristic part of this modification is that the cross section along the vertical wall 24 of the convex portion as the correcting means has an arc shape.

 FIG. 4 is a view similar to FIG. 2 showing a pair of convex portions 29 and concave portions 30 according to a modification. The upper end surface 17a of the mounting table 17 and the lower end surface 24a of the vertical wall 24 are provided with a convex portion 29 on the upper end surface 17a and a concave portion 30 on the lower end surface 24a as correcting means.

  The convex portion 29 is provided at the edge portion of the mounting table 17 so that the cross section along the plane defined by the x and y directions has an arc shape, and is formed with substantially the same thickness as the vertical wall 24. The concave portion 30 is formed so that the convex portion 29 can be fitted therein. When the lower end surface 24a of the vertical wall 24 and the upper end surface 17a of the mounting table 17 are in contact with each other with the sheet 22 interposed therebetween, the positions of the lower table 11 and the upper table 12 are displaced along the x direction, and the convexity Even if the arcuate surface portion 29a of the portion 29 and the opening end portion 30a of the concave portion 30 come into contact with each other with the sheet 22 sandwiched between them, if the lower table 11 and the upper table 12 are brought closer to each other, The projecting portion 29 and the recessed portion 30 are completely fitted together by sliding with each other while the 30 open end portions 30a are in contact with each other with the sheet 22 interposed therebetween. For this reason, the convex portion 29 and the concave portion 30 can correct the positional deviation between the lower table 11 and the upper table 12 in the direction along the vertical wall 24.

  According to the present modification, the lower table 11 and the upper table 12 can be positioned without relying on human hands by the pair of convex portions 29 and the concave portions 30 provided at four places, as in the first embodiment.

In the above-described first embodiment and its modifications, the convex portions 26 and 29 as correcting means are formed on the upper end surface 17 a of the mounting table 17, and the concave portions 27 and 30 are formed on the lower end surface 24 a of the vertical wall 24. However, this may be reversed. That is, the concave portions 27 and 30 can be formed on the upper end surface 17 a of the mounting table 17, and the convex portions 26 and 29 can be formed on the lower end surface 24 a of the vertical wall 24. In this case, since the concave portions 27 and 30 are provided on the upper end surface 17 a of the mounting table 17, the concave portions 27 and 30 are formed so as to be recessed from the upper end surface 17 a so that the convex portions 26 and 29 can be fitted. For this reason, if the longitudinal section perpendicular to the vertical wall 24 has a rectangular shape as described above, the convex portions 26 and 29 are displaced in the direction perpendicular to the vertical wall 24 (the z direction in FIG. 2). When it does, a pair of convex parts 26 and 29 and recessed parts 27 and 30 cannot fit. Then, since the positional deviation cannot be corrected by the pair of convex portions 26 and 29 and the concave portions 27 and 30, the vertical cross section perpendicular to the vertical wall 24 also needs to be formed in a trapezoidal shape or an arc shape. For example, if a longitudinal section along the vertical wall 24 of the projections 26 and 29 are trapezoidal, convex portions 26 and 29 formed in a frustum shape, along the vertical wall 24 of the projections 26 and 29 When the longitudinal section is arcuate, the convex portions 26 and 29 may be formed in a shape obtained by cutting the spheroid in half.

  Further, the pair of convex portions 26 and 29 and the concave portions 27 and 30 are provided on the upper end surface 17a of the mounting table 17 and all the lower end surfaces 24a of the four vertical walls 24, respectively. 26, 29 and the recesses 27, 30 can correct the positional deviation in one direction, so that the lower end surface 24a of the two adjacent vertical walls 24 and the upper end surface 17a of the mounting table 17 at a position aligned therewith. And the positional deviation between the lower table 11 and the upper table 12 in the direction along the plane defined by the x and z directions can be corrected. For this reason, as long as the pair of convex portions 26 and 29 and the concave portions 27 and 30 have a right angle relationship with each other, they may be provided only in two places, and the present invention is not limited to the above-described first embodiment and its modifications.

  Next, Example 2 will be described. In the second embodiment, as shown in FIG. 5, cylindrical lower guide posts 31 are erected at the four corners of the lower table 11 of the vacuum forming apparatus 10 of the first embodiment, and are cylindrical at the four corners of the upper table 12. This is an example in which the upper guide post 32 is placed downward and the upper and lower guide posts 31 and 32 are used to position the lower table 11 and the upper table 12. Since the basic configuration of the second embodiment is the same as that of the first embodiment, the same reference numerals as those in the first embodiment are assigned to the same functional parts, and detailed description thereof is omitted.

  The lower table 11 and the upper table 12 are moved closer to each other by the forming drive mechanism, and the lower end surface 24a of each vertical wall 24 of the upper table 12 sandwiches the sheet 22 and the upper end surface 17a of the mounting table 17 of the lower table 11 , The lower end surface 32a of the upper guide post 32 and the upper end surface 31a of the lower guide post 31 come into contact with each other.

  FIG. 6 is an enlarged view of the upper end surface 31a of the lower guide post 31 in contact with the lower guide post 31 and the lower end surface 32a of the upper guide post 32 shown in FIG. 5, and FIG. 7 is a cross-sectional view of FIG.

  As shown in FIGS. 6 and 7, a protrusion 33 is formed on the upper end surface 31 a of the lower guide post 31. The protrusion 33 has a columnar base portion 33a provided on the upper end surface 31a, and a truncated cone-shaped upper portion 33b formed integrally with the base portion 33a.

  A fitting hole 34 having a circular cross section is formed in the lower end surface 32 a of the upper guide post 32. The fitting hole 34 is formed so as to receive the protrusion 33. The open end 34 a of the fitting hole 34 is formed with a diameter-expanded portion 34 b that makes it easier to receive the protrusion 33. An inclined surface 34d is formed on the inner wall 34c of the fitting hole 34 in order to disperse the stress when the protrusion 33 is fitted.

  In the upper guide post 32, a plurality of grooves 35 are formed along the vertical direction on the outer peripheral surface 32b of the portion where the fitting hole 34 is formed. Here, the protrusion 33 and the fitting hole 34 form a correcting means.

  According to the vacuum forming apparatus 10 described in the second embodiment, when the forming drive mechanism works and the lower table 11 and the upper table 12 are relatively close to form the sheet 22, the lower guide post 31 and the upper guide post 32 are respectively formed. The lower table 11 and the upper table 12 are positioned so as to be aligned by the provided protrusion 33 and the fitting hole 34. That is, if the positions of the lower table 11 and the upper table 12 are shifted from each other during molding, the distal end side portion 33c of the upper portion 33b of the projection 33 provided on the upper end surface 31a of the lower guide post 31 is moved to the upper guide post 32. It engages and gets caught by the enlarged diameter part 34b formed in the fitting hole 34 at the lower end of the. When the lower table 11 and the upper table 12 are brought closer to each other, the protruding portion 33 and the fitting hole 34 are completely fitted together by sliding the tip side portion 33c and the enlarged diameter portion 34b in contact with each other. The positional deviation between the lower table 11 and the upper table 12 is corrected.

  In addition, since a plurality of grooves 35 are formed so as to surround the outer peripheral surface 32b in the portion where the fitting hole 34 of the upper guide post 32 is provided, the tip side portion 33c of the protrusion 33 and the fitting hole are formed. Even when a load is concentrated on a portion of the peripheral wall portion 34e that defines the fitting hole 34 that is in contact with the distal end side portion 33c, when the positional deviation is corrected by sliding while sliding on the enlarged diameter portion 34b of the 34. Since the load is distributed in the direction along the groove 35, the peripheral wall portion 34e is difficult to bend. For this reason, when the positional deviation between the lower table 11 and the upper table 12 is corrected by the projection 33 and the fitting hole 34, the positional deviation can be corrected accurately by bending the peripheral wall portion 34e of the fitting hole 34. The possibility of disappearing is reduced, and the pressing mechanism 28 and the molding die 18 can be aligned.

  Therefore, according to the vacuum forming apparatus 10 described in the second embodiment, similarly to the first embodiment, the lower table 11 and the upper table 12 can be positioned when the sheet 22 is vacuum formed, and the pressing mechanism 28 is used. The molding assistance can be performed accurately without relying on human hands, and the sheet 22 can be reliably formed into the shape of the molding die 18.

  In the second embodiment, the protrusion 33 and the fitting hole 34 provided on the lower guide post 31 and the upper guide post 32 are provided on the upper end surface 31 a of the lower guide post 31. Although the fitting hole 34 was provided in the lower end surface 32a of 32, this can also be reversed. That is, the fitting hole 34 may be provided on the upper end surface 31 a of the lower guide post 31, and the protrusion 33 may be provided on the lower end surface 32 a of the upper guide post 32. In this case, the same effect as in the second embodiment can be obtained.

  The open end portion 34a of the fitting hole 34 is provided with the enlarged diameter portion 34b, but this can be eliminated. However, it is desirable to provide the enlarged-diameter portion 34b because the protrusion 33 and the fitting hole 34 are easy to receive when the fitting is performed while correcting the positional deviation.

  In addition, the fitting hole 34 may have a cylindrical shape as long as the protruding portion 33 can be fitted, for example, without providing the oblique side surface 34d on the back wall 34c of the fitting hole 34. It is not limited to the examples described.

  The protruding portion 33 has a columnar base portion 33a and a truncated cone-shaped upper portion 33b. However, it is only necessary that the protruding portion 33 and the fitting hole 34 are able to correct misalignment by sliding each other. It is not limited to the example described in Example 2. For example, the entire protrusion 33 may be formed in a truncated cone shape or a cone shape, and the truncated cone-shaped upper portion 33b may be formed in a cone shape. Further, the same effect can be obtained even if the protrusion 33 is formed in a polygonal frustum shape or a polygonal pyramid shape having a substantially circular cross section.

  The plurality of grooves 35 are provided on the outer peripheral surface 32b of the portion where the fitting hole 34 of the upper guide post 32 is provided. Even if this is omitted, the same effect as in the second embodiment can be obtained. However, since the groove 35 can suppress the bending of the peripheral wall portion 34e defining the fitting hole 34 when the positional deviation between the lower table 11 and the upper table 12 is corrected, the positional deviation can be corrected more reliably. Since it is possible, it is desirable to provide the groove 35.

  The lower guide posts 31 are provided at the four corners of the lower table 11 and the upper guide posts 32 are provided in accordance with the lower guide posts 31. However, it is sufficient if the positional deviation between the lower table 11 and the upper table 12 can be corrected. It is not limited to the example described in Example 2. For example, only one pair of the guide posts 31 and 32 may be provided on the lower table 11 and the upper table 12. However, since both the guide posts 31 and 32 correct the misalignment between the lower table 11 and the upper table 12 by fitting the protrusion 33 and the fitting hole 34, the protrusion 33 and the fitting hole are corrected at the time of correction. It is desirable to provide three or more pairs in order to evenly distribute the force applied to 34 and stabilize the lower table 11 and the upper table 12.

  Further, when the upper end surface 31 a of the lower guide post 31 that contacts the lower end surface 30 a of the upper guide post 32 is formed at the same height as the upper end surface 17 a of the mounting table 17, both the guide posts 31 and 32 maintain the vacuum forming apparatus 10. The possibility of hindering such operations is reduced, and the work efficiency can be increased.

It is sectional drawing which shows Example 1 of the vacuum forming apparatus which concerns on this invention. It is the elements on larger scale which expand and show the part in which the correction means of FIG. 1 was provided. It is sectional drawing which shows the time of shaping | molding of the vacuum forming apparatus which concerns on this invention. FIG. 6 is a partially enlarged view similar to FIG. 2 illustrating a modification of the first embodiment. It is sectional drawing which shows Example 2 of the vacuum forming apparatus which concerns on this invention. It is the elements on larger scale which expand and show the part in which the correction means of FIG. 5 was provided. Sectional drawing in FIG. 6 is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vacuum forming apparatus 11 Lower table 12 Upper table 13 Drive shaft 15 (as part of molding drive mechanism) Drive shaft 18 (as part of molding drive mechanism) Mold 18a (die) surface 19 Hole 21 Holding Mechanism 22 Sheet 23 Frame member 24 Vertical wall 24a Lower end face 26, 29 Convex part 27, 30 Concave part 28 Press mechanism 31 Lower guide post 31a Upper end face 32 Upper guide post 32a Lower end face 32b Outer peripheral face 33 Projection part 34 Fit hole 34a Open End 34b Expanded portion 35 Groove

Claims (3)

A mold having a plurality of vacuuming holes formed on the mold surface;
A lower table on which the molding die is placed;
A holding mechanism for temporarily holding a sheet softened by heating to be molded by the molding die above the molding die;
An upper table disposed above the lower table across the sheet and having a rectangular frame member with an open lower end;
At the time of molding the sheet, the lower table and the upper table are moved relative to each other in a direction to bring them closer to each other so that the sheet follows the surface of the molding die, and the lower end open end of the frame member surrounds the sheet. A molding drive mechanism for holding the sheet in close contact with the surface of the molding die by sandwiching the sheet and the lower table, and performing vacuuming through the hole for vacuuming;
A vacuum forming apparatus provided inside the frame member and provided with a pressing mechanism that presses the sheet from the outside to the molding die side in order to remove wrinkles generated in the sheet;
At the edge of the lower table, a plurality of columnar lower guide posts, and at the edge of the upper table, a plurality of columnar upper guide posts corresponding to the lower guide post, when molding the sheet , Provided that the upper end surface of the lower guide post and the lower end surface of the upper guide post abut each other,
As a correcting means for correcting a relative positional shift in the direction perpendicular to the up-and-down movement direction of the upper table and the lower table, at least a part of the upper end surface of the lower guide post has a diameter dimension as it goes upward. A protrusion having a conical shape or a truncated cone shape gradually decreasing, and a fitting hole into which the protrusion can be fitted is formed in the lower end surface of the upper guide post, or the lower portion of the upper guide post The end surface can be fitted with a protrusion having an inverted conical shape or an inverted truncated cone shape with a diameter dimension gradually decreasing as at least a portion thereof is directed downward, and the upper end surface of the lower guide post can be engaged with the protrusion. Each fitting hole is formed,
In the lower guide post and the upper guide post, a groove is formed along the vertical direction on the outer peripheral surface of the portion where the fitting hole is formed. Wherein the open end of the fitting hole, vacuum forming apparatus according to claim 1, wherein the enlarged diameter portion for facilitating receiving the protrusion is provided. The vacuum forming according to claim 1 or 2 , wherein the lower guide post has an upper end surface that is flush with an upper end surface on which the molding die is placed on the lower table. apparatus.

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