CA2196929C - Thin sheet forming dies - Google Patents
Thin sheet forming dies Download PDFInfo
- Publication number
- CA2196929C CA2196929C CA 2196929 CA2196929A CA2196929C CA 2196929 C CA2196929 C CA 2196929C CA 2196929 CA2196929 CA 2196929 CA 2196929 A CA2196929 A CA 2196929A CA 2196929 C CA2196929 C CA 2196929C
- Authority
- CA
- Canada
- Prior art keywords
- cylindrical member
- lower die
- die
- slide cam
- portions
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D19/00—Flanging or other edge treatment, e.g. of tubes
- B21D19/08—Flanging or other edge treatment, e.g. of tubes by single or successive action of pressing tools, e.g. vice jaws
- B21D19/082—Flanging or other edge treatment, e.g. of tubes by single or successive action of pressing tools, e.g. vice jaws for making negative angles
- B21D19/086—Flanging or other edge treatment, e.g. of tubes by single or successive action of pressing tools, e.g. vice jaws for making negative angles with rotary cams
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Bending Of Plates, Rods, And Pipes (AREA)
- Mounting, Exchange, And Manufacturing Of Dies (AREA)
Abstract
A thin sheet forming die with a forming portion to be a negative angle when the second die is moved in the straight line direction and abutted to the first die to form thin sheets, comprising a cylindrical rotating cam with a groove formed in the axial direction rotatably mounted to the first die, a negative angle forming portion formed in the groove edge portion of the rotating cam, a slide cam with a negative angle forming portion equipped to the second die in such a manner to be opposite to the said rotating cam, and an automatic return device equipped to the first die for rotating and retracting the rotating cam to the condition in which the work is removed from the first die after forming, wherein an excessively bent negative angle forming portion is designed to be processed with one rotating cam equipped with a plurality of cylindrical rotating cam portions in varying diameters.
Description
2~ 96829 THIN SHEET FORMING DIES
BACKGROUND OF THE INVENTION
FIELD OF THE INDENTION
The invention relates to thin sheet forming dies.
DESCRIPTION OF THE PRIOR ART
The negative angle of thin sheets such as sheet metal or plastics is generally formed by the use of a slide cam.
Now, the negative angle forming referred to here means forming with a forming portion which comes inwards towards the lower die from the working locus of the upper die when the work loaded on the lower die is formed by descending the upper die in the vertical direction for abutting.
In the conventional negative angle forming of thin sheet products, the work is loaded on the lower die and the upper die descends downwards in the vertical direction to drive the driven cam of the lower die by the driving cam of the upper die, and the work is processed from the lateral direction, and when processing completes and the upper die ascends, the driven cam is retracted by springs.
In this event, the forming portion of the driven cam which slides and forms the work from the outward lateral direction of the work is formed in the integrated profile identical to that of the forming portion of the work, but the forming portion of the lower die with the work loaded must be designed to divide and retract the portion forming a negative angle of the lower die, or the rear portion forming the negative angle is deleted and the work is moved forwards to enable the removal of the work. When the degree of negative angle is small, no serious problems occur but when the degree of negative angle is great or the product has a slender frame-like cross section with grooves, for example, parts such as front pillar outer of automobile sheet metal parts, due to the narrow groove width of the work, not only the.profile is unable to be clearly formed at the forming portion of the driven cam when the portion of the lower die serving as an negative angle is divided or deleted, but also the strength of the lower die lacks and it is impossible to carry out negative angle forming.
In negative angle forming using the slide cam, the driven cam is slid in a considerably long straight distance for forming, it is not always easy to repeatedly slide the driven cam exactly to a specified position and it is difficult to produce products with stable quality. In addition, there are cases in which distortion or bend is generated in products and the products must be touched up, but it is practically impossible to touch up products for parts composing the automobile outer plate portions such as side panels, front fenders, roofs, bonnets, trunk lids, door panels, or front pillar outers, because they have three-dimensional curved surfaces and profiles. In the case of automobile sheet metal assembly, if any distortion or bend is generated in products, it is difficult to combine such products with other parts and it is unable to provide high-quality automobile sheet metal structure and to maintain a specified product accuracy of thin-plate formed products.
When the slide cam is used, a large driven cam and heel must be mounted on the side portion with the work of the lower die loaded, requiring a large loxer-die area, increasing the die weight as 'uch, and resulting in expensive dies.
Therefore, in order to solve the above problems, a forcing Dethod of thin sheets and the forming dies in which the linear upward and downward sotion of a press is converted into rotary motion has already been proposed by the present applicant under Japanese Patent Publication No. Sho 63-u1662.
Referring now to Figs. 4-8, the forcing dies rill be described in further detail.
FIG. 4 shows right and left schematic perspective views of a complete front pillar outer, an automobile sheet metal part formed by the forming dies. In the figure, the bottom shows the front pillar outer for the right side and the top for the Ieft side. This front pillar outer constitutes part of the front _2_ Z~96929 door frame, also part of the front wind shield frame, and in addition part of the frame supporting the roof panel, and comprises the joint part with other many parts, and is a product for which severe product accuracy is required, and if the required accuracy is not satisfied, it is unable to provide a sheet metal car body with good quality.
Because the front pillar outer composes the outer plate portion of the automobile, it has three-dimensional curved surfaces and profiles.
The portion with the negative angle formed by this forming dies is shown with letter F, whose cross section is shown as work W in Fig. 8.
That is, after the negative angle is formed, the work W achieves the condition shown in Fig. 8 from the condition shown in Fig. 5. By the way, this press-working process includes drawing which takes place first, then, peripheral trimming to the condition shown in Fig. 5, and this forming process as the succeeding third process.
With respect to the lower die 100, a cylindrical rotating cam 102 formed with an axial groove 101 is rotatably mounted to the lower die proper 103. The lower die proper 103 is securely fixed to the lower substrate 121 with a bolt 122. The top surface of the lower die proper 103 is formed in a shape that can receive the work W, and a negative angle forming portion i04 is formed at the edge portion of the groove 10i of the rotating cam 102 nearest to the top surface of the lower die 103. An automatic return device 105~which rotates and retracts the rotating cam 102 is embedded in the lower die proper 103 so that the work W can be removed from the lower die proper 103 after forming. Tn this example, the automatic return device 105 brings a push pin 107 energized by coil spring 106 in contact with the bottom surface of the tip end of the rolling plate 108 securely fixed to the surface opposite to the negative angle forming portion 104 of the groove 101 of the rotating cam 102 with a bolt 15i. For the automatic return device 105, pneumatic devices, hydraulic devices, link mechanisms, cams, or other similar mechanisms may be used, and may be mounted not only to the lower die 100 but also between the upper die 109 and the lower ~~9b929 die 100.
On the other hand, to the upper die 109, a slide cam 1i0 is mounted to the position opposite to the said rotating cam 102. This slide cam 110 has the negative angle forming portion 112 formed at the bottom end, the slide cam 110 is guided by the guide (not illustrated), and is energized in the outward direction of the die by a coil spring 117 compressedly mounted between the slide cam 110 top surface and the inclined guide 154 bottom surface securely fixed to the top substrate 152 with a bolt 153. The slide cam 110 is stopped by a stopping plate 156 securely affixed to the inclined guide 154 with a bolt 155. The pad 157 is energized downwards by a coil spring 158, is hung from the top substrate 152 with the hang volt 119, and strongly presses the work W
against the lower die proper 103 to prevent the work W from moving before the negative angle is formed on the work W.
Next description will be made on the operation of this forming die.
First of all, as shown in Fig. 5, the upper die 109 is located at the top dead center, and then, the Work W is loaded on the lower die proper 103 of the lower die 100. In this event, the rotating cam 102 is rolled and retracted by the automatic return device 105.
Then, the upper die 109 begins descending and as shown in Fig. 6, first of all, the bottom surface of the slide cam 110 comes in contact with the rolling plate 108 to rotate the rotating cam 102 clockwise in Fig. 6 without causing the slide cam 110 to interfere with the negative angle forming portion 104 of the rotating cam 102.
As the upper die 109 continues to descend further, the slide cam 110 energized in the outward direction of the die resists against the energizing force of the coil spring 117, moves to the left in the lateral direction by the operation of the cam, enters the state shown in Fig. 7, and the negative-angle forming portion 104 of the rolled rotating cam 102 cooperates with the negative-angle forming portion 112 of the slide cam 110 to negative-angle form the work W.
After negative angle is formed, the upper die 109 begins rising. The slide 2'96929 cam 110 is energized in the outward direction of the die by the coil spring 117, moves to the right in Fig. 8, and ascends without interfering with the work W
with the negative angle formed.
On the other hand, the rotating cam 102 rotates to the right in Fig. 8 by the automatic return device because the slide cam 110 being restrained ascends, enabling the work W to be removed without interfering with the negative angle forming portion 10~t of the rotating cam 102 when the negative-angle formed work W is removed from the lower die 103.
The formed thin sheet products had the negative angle formed using the rotating cam as described above, but because the rotating cam rotates around the rotation axis to process the work, if the work is nearly linear and is riot greatly bent, the negative angle forming portion can enter one of the cylindrical rotating cams in the same diameter and is able to be processed, but if the work is greatly bent, the negative angle forming portion is unable to completely enter one of the cylindrical rotating cams in the same diameter and is unable to be processed.
In particular, automobile sheet metal parts including door panels have many bent portions, and in recent years, there are many negative angle forming portions from the viewpoint of designs in addition to conventional bent portions, and it is demanded to form these negative angle forming portions in one process without undergoing many processes and to improve production efficiency.
SUMMARY OF THE INDENTION
Therefore, under these circumstances, this invention relates to a forming die of thin sheets for forming the greatly bent negative angle forming portion with one rotating cam equipped with a plurality of cylindrical rotating cam portions in varying diameters.
The size of the rotating cam diameter is practically unable to be excessively increased from the viewpoint of fabricating dies, and is, for 2'9~9~9 example, about 320 mm, and for the greatly bent work, the bent portions are processed by one rotating cam equipped with a plurality of cylindrical rotating cam portions in varying diameters.
The diameters are varied at a required position of the rotation axis in accord with the degree of the bend of the work. Special consideration shall be given to the size of diameter of the rotating cam so that the negative angle forming portion of the rotating cam does not become excessively acute. Because the negative angle forming portion becomes excessively acute, the strength lacks, and it is preferable to take care to prevent it from becoming 30° or less.
When a plurality of rotating cams are used, their end faces may interfere with one another at the joints of adjoining rotating cams when the rotating cams are rotated, but the dies according to this invention are completely free of such interference because in this invention, one rotating cam is used.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a plan view of one specific embodiment according to this invention;
Fig. 2 shows two cross-sectional views of the work taken on line ~j-jII of Fig. 1 before and after negative-angle forming;
Fig. 3 is a longitudinal cross-sectional view taken on line ~j-~j of Fig.
1;
Fig. b shows schematic right and left perspective .views of the completed front pillar outer, a sheet metal part of automobiles;
Fig. 5 is a longitudinal cross-sectional view when the upper die of the forming dies to form negative angles for the front pillar outer of Fig. a is in the top dead center condition;
Fig. 6 is a longitudinal cross-sectional view of the upper die of the forming dies of Fig. 5 which descends to come in contact with the lower die;
Fig. 7 is a longitudinal cross-sectional view of the upper die of the forming dies of Fig. 5 in the bottom dead center condition; and Fig: 8 is a longitudinal cross-sectional viex of the upper die xhich ascends and is in the top dead center condition after the forming dies of Fig.
finish negative-angle forming.
cuonnTUCUTo Referring nox to one specific embodiment shown in FIG. 1-3> this invention will be described in further detail.
The work W formed by the forming dies according to this invention is an automobile trunk lid outer as shown in Fig. 1, and the recessed circular arc curved portion of the front edge portion of the trunk lid outer as viexed from the plane is negative-angle formed, and as shoxn in Fig. 2, it is negative-angle formed to have a cross-section shown below from that shown above.
Fig. 1 shows a plan view of the thin sheet forming dies, Fig. 2 the condition of a flange 1 before and after the xork W, Fig. 3 a longitudinal cross-sectional view taken on the line jQ-]j[ of Fig. 1.
The processed portion of the work W of the thin sheet forming dies is the rear edge portion of the trunk lid outer and as clear from Fig. 1, it is a protruded form as seen from the plane, and both end portions are considerably displaced forxards. If this is processed xith one piece of rotating cam, an extremely large rotating'cam is required. Excessively increasing the size is practically impossible in fabricating dies, and is about 320 mm in diameter at maximum. In addition, the flange angle differs at the center portion and both end portions, and there is a ease in xhich the negative-angle forming portion of the rotating cam becomes too acute to maintain the strength. In this invention, the rotating cam is formed into a small-diameter center rotating cam portion at the center portion and large-diameter both ends rotating can portions at both ends.
On both ends of the small-diameter center rotating cam portion 2 of the rotating axis CA in Fig. 1, a rotating cam; 3 comprising large-diameter edge portion rotating cam portions 3 are arranged. As is clear from Fig. 3, the large-diameter edge portions rotating cam portions 3 are concentric to the small-diameter center rotating can portion 2, and has a larger diameter than that of the small-diameter center rotating cam portion 2. For example, the diameter of the large-diameter edge portions rotating cam portions is 290 mm, and that of the small-diameter center portion rotating cam portion is 250 mm.
The lower die 5 has a support block 8 fixed to the lower die base 6 with a bolt 7, and rotatably supports the cylindrical Iarge-diameter edge portion rotating cam 3 with a groove 10 formed axially in a horizontal slot groove 9 at the top center of the support block 8.
In this embodiment, an air cylinder 11 is equipped as an automatic return device of the rotating cam 4 in Fig. 1. Needless to say, the automatic return device is not limited to an air cylinder but a spring, hydraulic equipment, link mechanism, cam, or any mechanisms similar to these may be used, and can be mounted not only to the lower die but also to the upper die.
A connecting member 12 is fixed to the bottom surface of the small-diameter center rotating cam 2, and_to the tip end of a piston rod 15 of the air cylinder whose base end is pivotally mounted via the bracket 14 fixed to the support block 8 with a bolt 13, the said connecting member 12 is pivotally mounted, so that the piston rod l5,is contracted to return the large-diameter center rotating cam 2. At the bottom portion of the slot groove 9 of the support block 8, a Window slot is provided for allowing the connecting member 12 to rotate.
At the edge portion of the groove 10 of the edge portion rotating cam portion 3. a negative angle forcing portion 16 is formed, and a rolling plate 17 is fixed to the side opposite to the negative angle forming portion 16 of the groove 10 with a bolt 18. The negative angle forming portion 16 of the Iarge diameter edge portion rotating cam portion 3 is formed into a work support portion l9 in the profile same as the bottom surface of the xork W so that the work 41 is supported, and a work loading portion 20 in the profile same as the bottom surface of the cork IJ is forned slightly outwards in the upper portion -g-linked to the work supporting portion 19 of the edge portion rotating cam portion 3 of the support block 8.
The upper die 21 has a support block 23 fixed to the lower surface of the upper die base 22 with a bolt 24, and a Wear plate 25 fixed to the loxer inclined surface of the support block 23with a bolt 26, and the slide caa 27 is held by a guide plate (not illustrated) and slid on the lower surface of the wear plate 25. On the top surface of the slide cam 27, the negative angle forming portion 28 is fixed With a bolt 29, at the opposite position to the groove 10 of the edge portion rotating cam 3 of the slide cam 27.
On the top inclined surface of the slide cam 27, a support plate 129is fixed xith a bolt 30, and betxeen this support plate 129 andthe supportplate fixed to the support block 23, a coil spring 32 is compressedly mounted to energize the slide cam 27 to the outward direction of the die.
The said coil spring 32 is mounted in the externally fitted form to the positioning pin 33 screwed into the support plate 31, and the tip end of the said positioning pin 33 allows a stopping plate 34 fixed to the side surface opposite to the support plate 31 to pass through_ When the upper die 21 rises, the slide cam 2? moves outwards of the die until the support plate 129 comes in contact xith the stopping plate 3u by the energizing force of the coil spring 32.
Though it is not illustrated, in order to stably support the work W, the positioning member of the work H is mounted to the lower die 5, and to the upper die 21, as described in the conventional example, a pad for pressurizing the work W is mounted to the lower die 5, but as these would make the illustration complicated and essential points of this invention difficult to understand, the positioning member and the pad are omitted.
At the center portion of the work W, the small-dianeter center rotating can portion 2 is shown with an alternate long and two short dashes line, and others are nearly identical to the large-diameter rotating cam portion.
Next description will be made on the operation of the thin sheet forming _g_ 2'96929 dies.
The condition shown in Fig. 3 is the bottom dead center condition and corresponds to Fig. 7 of the conventional example.
In this invention, it is not illustrated but as shown in Fig. 5 of the conventional example, the upper die 21 is located at the top dead center, when the work W is loaded to the work support portions 20 of the lower die 5. In this event, the center rotating cam 4 is rolled to retract by the air cylinder 11.
Next, as shown in Fig. 6 of the conventional example, in the upper die 21, the inclined surface ~1 of the slide cam 27 comes in contact with the rolling plate 17 without allowing the slide cam 27 to interfere with the negative angle forming portion 16 of the small-diameter center rotating cam 2 and large-diameter edge portion rotating cam portion 3, causing the small-diameter center rotating cam 2 and large-diameter edge portion rotating cam portion 3 to rotate counterclockwise (the rolling direction is reversal in the conventional example and this embodiment).
As the upper die 21 further continues to descend, the slide cam 27 energized in the outward direction of the dies resist against the energizing force of the coil spring 32 and moves to the right in the lateral direction by the action of the cam, and enters the condition shown in Fig. 7 of the conventional example, that is, the condition shown in Fig. 3, and the negative angle forming portion 16 of the rolled small-diameter center rotating cam portion 2 and large-diameter edge portion rotating cam 3 cooperate with the negative angle forming portion 28 of the slide cam 27 to negative-angle form the work W.
After negative-angle forming, the upper die 21 begins to ascend. The slide cam 27 is energized in the outward direction of the dies by the coil spring 32, moves to the left as shown in Fig. 8 of the conventional example, and ascends without interfering with the negative-angle formed work W.
On .the other hand, when the restrained slide cam 27 ascends and the air cylinder 11 contracts the piston rod 15, the small-diameter center rotating can portion 2 and the large-diameter edge portion rotating cam portion 3 rotate in the left direction to enable the removal of the xork B xithout interfering xith the negative angle forming portion 16 of the small-diameter center rotating cam portion 2 and the large-diameter edge portion rotating cam portion 3, xhen the negative-angle formed work W is removed from the lower die 5.
This invention is a forming die with a forming portion to achieve a negative angle when the second die is moved in the straight line to abut the first die for forming, and in the thin sheet forming dies in which a cylindrical rotating cam xith a groove formed in the axial direction is rotatably mounted to the first die, a negative angle forming portion is formed in the groove edge portion of the rotating cam, a slide cam with the negative angle forming portion is mounted to the second die in such a manner to be opposite to the said rotating cam, an automatic return device for rotating and retracting the rotating can to enable the removal of the xork from the first die after forming is mounted to the first die, because it is a thin sheet forming die designed to process an excessively bent negative angle forming portion xith one rotating cam equipped xith a plurality of cylindrical rotating cam portions xith varying diameters, it becomes possible to form an excessively bent negative angle forming portion xith one forming die, to reduce the number of processes, and to improve the processing accuracy.
In particular, the thin sheet forming die according to this invention is suited for negative-angle forming the protruded circular arc curved portion as seen from the plane. This is because the flange to be formed becomes a shrinkage flange as it is protruded and tends to generate xrinkles at the time of forming, requiring bottom pushing processing. In this invention, because the rotating cams are formed integrally, bottom pushing forming is possible in high accuracy.
Because an excessively bent negative forming section is formed into a plurality of diameter portions in this invention, it is possible to give 2'96929 consideration to prevent the negative-angle forming portions of the rotating cams from being excessively acute, and the rotating cams are free of short strength.
In addition, when a plurality of rotating cams are used, their end faces may interfere with one another at the joints of adjoining rotating cams when the rotating cams are rotated, but the dies according to this invention are completely free of such interference because in this invention, one rotating cam is used.
BACKGROUND OF THE INVENTION
FIELD OF THE INDENTION
The invention relates to thin sheet forming dies.
DESCRIPTION OF THE PRIOR ART
The negative angle of thin sheets such as sheet metal or plastics is generally formed by the use of a slide cam.
Now, the negative angle forming referred to here means forming with a forming portion which comes inwards towards the lower die from the working locus of the upper die when the work loaded on the lower die is formed by descending the upper die in the vertical direction for abutting.
In the conventional negative angle forming of thin sheet products, the work is loaded on the lower die and the upper die descends downwards in the vertical direction to drive the driven cam of the lower die by the driving cam of the upper die, and the work is processed from the lateral direction, and when processing completes and the upper die ascends, the driven cam is retracted by springs.
In this event, the forming portion of the driven cam which slides and forms the work from the outward lateral direction of the work is formed in the integrated profile identical to that of the forming portion of the work, but the forming portion of the lower die with the work loaded must be designed to divide and retract the portion forming a negative angle of the lower die, or the rear portion forming the negative angle is deleted and the work is moved forwards to enable the removal of the work. When the degree of negative angle is small, no serious problems occur but when the degree of negative angle is great or the product has a slender frame-like cross section with grooves, for example, parts such as front pillar outer of automobile sheet metal parts, due to the narrow groove width of the work, not only the.profile is unable to be clearly formed at the forming portion of the driven cam when the portion of the lower die serving as an negative angle is divided or deleted, but also the strength of the lower die lacks and it is impossible to carry out negative angle forming.
In negative angle forming using the slide cam, the driven cam is slid in a considerably long straight distance for forming, it is not always easy to repeatedly slide the driven cam exactly to a specified position and it is difficult to produce products with stable quality. In addition, there are cases in which distortion or bend is generated in products and the products must be touched up, but it is practically impossible to touch up products for parts composing the automobile outer plate portions such as side panels, front fenders, roofs, bonnets, trunk lids, door panels, or front pillar outers, because they have three-dimensional curved surfaces and profiles. In the case of automobile sheet metal assembly, if any distortion or bend is generated in products, it is difficult to combine such products with other parts and it is unable to provide high-quality automobile sheet metal structure and to maintain a specified product accuracy of thin-plate formed products.
When the slide cam is used, a large driven cam and heel must be mounted on the side portion with the work of the lower die loaded, requiring a large loxer-die area, increasing the die weight as 'uch, and resulting in expensive dies.
Therefore, in order to solve the above problems, a forcing Dethod of thin sheets and the forming dies in which the linear upward and downward sotion of a press is converted into rotary motion has already been proposed by the present applicant under Japanese Patent Publication No. Sho 63-u1662.
Referring now to Figs. 4-8, the forcing dies rill be described in further detail.
FIG. 4 shows right and left schematic perspective views of a complete front pillar outer, an automobile sheet metal part formed by the forming dies. In the figure, the bottom shows the front pillar outer for the right side and the top for the Ieft side. This front pillar outer constitutes part of the front _2_ Z~96929 door frame, also part of the front wind shield frame, and in addition part of the frame supporting the roof panel, and comprises the joint part with other many parts, and is a product for which severe product accuracy is required, and if the required accuracy is not satisfied, it is unable to provide a sheet metal car body with good quality.
Because the front pillar outer composes the outer plate portion of the automobile, it has three-dimensional curved surfaces and profiles.
The portion with the negative angle formed by this forming dies is shown with letter F, whose cross section is shown as work W in Fig. 8.
That is, after the negative angle is formed, the work W achieves the condition shown in Fig. 8 from the condition shown in Fig. 5. By the way, this press-working process includes drawing which takes place first, then, peripheral trimming to the condition shown in Fig. 5, and this forming process as the succeeding third process.
With respect to the lower die 100, a cylindrical rotating cam 102 formed with an axial groove 101 is rotatably mounted to the lower die proper 103. The lower die proper 103 is securely fixed to the lower substrate 121 with a bolt 122. The top surface of the lower die proper 103 is formed in a shape that can receive the work W, and a negative angle forming portion i04 is formed at the edge portion of the groove 10i of the rotating cam 102 nearest to the top surface of the lower die 103. An automatic return device 105~which rotates and retracts the rotating cam 102 is embedded in the lower die proper 103 so that the work W can be removed from the lower die proper 103 after forming. Tn this example, the automatic return device 105 brings a push pin 107 energized by coil spring 106 in contact with the bottom surface of the tip end of the rolling plate 108 securely fixed to the surface opposite to the negative angle forming portion 104 of the groove 101 of the rotating cam 102 with a bolt 15i. For the automatic return device 105, pneumatic devices, hydraulic devices, link mechanisms, cams, or other similar mechanisms may be used, and may be mounted not only to the lower die 100 but also between the upper die 109 and the lower ~~9b929 die 100.
On the other hand, to the upper die 109, a slide cam 1i0 is mounted to the position opposite to the said rotating cam 102. This slide cam 110 has the negative angle forming portion 112 formed at the bottom end, the slide cam 110 is guided by the guide (not illustrated), and is energized in the outward direction of the die by a coil spring 117 compressedly mounted between the slide cam 110 top surface and the inclined guide 154 bottom surface securely fixed to the top substrate 152 with a bolt 153. The slide cam 110 is stopped by a stopping plate 156 securely affixed to the inclined guide 154 with a bolt 155. The pad 157 is energized downwards by a coil spring 158, is hung from the top substrate 152 with the hang volt 119, and strongly presses the work W
against the lower die proper 103 to prevent the work W from moving before the negative angle is formed on the work W.
Next description will be made on the operation of this forming die.
First of all, as shown in Fig. 5, the upper die 109 is located at the top dead center, and then, the Work W is loaded on the lower die proper 103 of the lower die 100. In this event, the rotating cam 102 is rolled and retracted by the automatic return device 105.
Then, the upper die 109 begins descending and as shown in Fig. 6, first of all, the bottom surface of the slide cam 110 comes in contact with the rolling plate 108 to rotate the rotating cam 102 clockwise in Fig. 6 without causing the slide cam 110 to interfere with the negative angle forming portion 104 of the rotating cam 102.
As the upper die 109 continues to descend further, the slide cam 110 energized in the outward direction of the die resists against the energizing force of the coil spring 117, moves to the left in the lateral direction by the operation of the cam, enters the state shown in Fig. 7, and the negative-angle forming portion 104 of the rolled rotating cam 102 cooperates with the negative-angle forming portion 112 of the slide cam 110 to negative-angle form the work W.
After negative angle is formed, the upper die 109 begins rising. The slide 2'96929 cam 110 is energized in the outward direction of the die by the coil spring 117, moves to the right in Fig. 8, and ascends without interfering with the work W
with the negative angle formed.
On the other hand, the rotating cam 102 rotates to the right in Fig. 8 by the automatic return device because the slide cam 110 being restrained ascends, enabling the work W to be removed without interfering with the negative angle forming portion 10~t of the rotating cam 102 when the negative-angle formed work W is removed from the lower die 103.
The formed thin sheet products had the negative angle formed using the rotating cam as described above, but because the rotating cam rotates around the rotation axis to process the work, if the work is nearly linear and is riot greatly bent, the negative angle forming portion can enter one of the cylindrical rotating cams in the same diameter and is able to be processed, but if the work is greatly bent, the negative angle forming portion is unable to completely enter one of the cylindrical rotating cams in the same diameter and is unable to be processed.
In particular, automobile sheet metal parts including door panels have many bent portions, and in recent years, there are many negative angle forming portions from the viewpoint of designs in addition to conventional bent portions, and it is demanded to form these negative angle forming portions in one process without undergoing many processes and to improve production efficiency.
SUMMARY OF THE INDENTION
Therefore, under these circumstances, this invention relates to a forming die of thin sheets for forming the greatly bent negative angle forming portion with one rotating cam equipped with a plurality of cylindrical rotating cam portions in varying diameters.
The size of the rotating cam diameter is practically unable to be excessively increased from the viewpoint of fabricating dies, and is, for 2'9~9~9 example, about 320 mm, and for the greatly bent work, the bent portions are processed by one rotating cam equipped with a plurality of cylindrical rotating cam portions in varying diameters.
The diameters are varied at a required position of the rotation axis in accord with the degree of the bend of the work. Special consideration shall be given to the size of diameter of the rotating cam so that the negative angle forming portion of the rotating cam does not become excessively acute. Because the negative angle forming portion becomes excessively acute, the strength lacks, and it is preferable to take care to prevent it from becoming 30° or less.
When a plurality of rotating cams are used, their end faces may interfere with one another at the joints of adjoining rotating cams when the rotating cams are rotated, but the dies according to this invention are completely free of such interference because in this invention, one rotating cam is used.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a plan view of one specific embodiment according to this invention;
Fig. 2 shows two cross-sectional views of the work taken on line ~j-jII of Fig. 1 before and after negative-angle forming;
Fig. 3 is a longitudinal cross-sectional view taken on line ~j-~j of Fig.
1;
Fig. b shows schematic right and left perspective .views of the completed front pillar outer, a sheet metal part of automobiles;
Fig. 5 is a longitudinal cross-sectional view when the upper die of the forming dies to form negative angles for the front pillar outer of Fig. a is in the top dead center condition;
Fig. 6 is a longitudinal cross-sectional view of the upper die of the forming dies of Fig. 5 which descends to come in contact with the lower die;
Fig. 7 is a longitudinal cross-sectional view of the upper die of the forming dies of Fig. 5 in the bottom dead center condition; and Fig: 8 is a longitudinal cross-sectional viex of the upper die xhich ascends and is in the top dead center condition after the forming dies of Fig.
finish negative-angle forming.
cuonnTUCUTo Referring nox to one specific embodiment shown in FIG. 1-3> this invention will be described in further detail.
The work W formed by the forming dies according to this invention is an automobile trunk lid outer as shown in Fig. 1, and the recessed circular arc curved portion of the front edge portion of the trunk lid outer as viexed from the plane is negative-angle formed, and as shoxn in Fig. 2, it is negative-angle formed to have a cross-section shown below from that shown above.
Fig. 1 shows a plan view of the thin sheet forming dies, Fig. 2 the condition of a flange 1 before and after the xork W, Fig. 3 a longitudinal cross-sectional view taken on the line jQ-]j[ of Fig. 1.
The processed portion of the work W of the thin sheet forming dies is the rear edge portion of the trunk lid outer and as clear from Fig. 1, it is a protruded form as seen from the plane, and both end portions are considerably displaced forxards. If this is processed xith one piece of rotating cam, an extremely large rotating'cam is required. Excessively increasing the size is practically impossible in fabricating dies, and is about 320 mm in diameter at maximum. In addition, the flange angle differs at the center portion and both end portions, and there is a ease in xhich the negative-angle forming portion of the rotating cam becomes too acute to maintain the strength. In this invention, the rotating cam is formed into a small-diameter center rotating cam portion at the center portion and large-diameter both ends rotating can portions at both ends.
On both ends of the small-diameter center rotating cam portion 2 of the rotating axis CA in Fig. 1, a rotating cam; 3 comprising large-diameter edge portion rotating cam portions 3 are arranged. As is clear from Fig. 3, the large-diameter edge portions rotating cam portions 3 are concentric to the small-diameter center rotating can portion 2, and has a larger diameter than that of the small-diameter center rotating cam portion 2. For example, the diameter of the large-diameter edge portions rotating cam portions is 290 mm, and that of the small-diameter center portion rotating cam portion is 250 mm.
The lower die 5 has a support block 8 fixed to the lower die base 6 with a bolt 7, and rotatably supports the cylindrical Iarge-diameter edge portion rotating cam 3 with a groove 10 formed axially in a horizontal slot groove 9 at the top center of the support block 8.
In this embodiment, an air cylinder 11 is equipped as an automatic return device of the rotating cam 4 in Fig. 1. Needless to say, the automatic return device is not limited to an air cylinder but a spring, hydraulic equipment, link mechanism, cam, or any mechanisms similar to these may be used, and can be mounted not only to the lower die but also to the upper die.
A connecting member 12 is fixed to the bottom surface of the small-diameter center rotating cam 2, and_to the tip end of a piston rod 15 of the air cylinder whose base end is pivotally mounted via the bracket 14 fixed to the support block 8 with a bolt 13, the said connecting member 12 is pivotally mounted, so that the piston rod l5,is contracted to return the large-diameter center rotating cam 2. At the bottom portion of the slot groove 9 of the support block 8, a Window slot is provided for allowing the connecting member 12 to rotate.
At the edge portion of the groove 10 of the edge portion rotating cam portion 3. a negative angle forcing portion 16 is formed, and a rolling plate 17 is fixed to the side opposite to the negative angle forming portion 16 of the groove 10 with a bolt 18. The negative angle forming portion 16 of the Iarge diameter edge portion rotating cam portion 3 is formed into a work support portion l9 in the profile same as the bottom surface of the xork W so that the work 41 is supported, and a work loading portion 20 in the profile same as the bottom surface of the cork IJ is forned slightly outwards in the upper portion -g-linked to the work supporting portion 19 of the edge portion rotating cam portion 3 of the support block 8.
The upper die 21 has a support block 23 fixed to the lower surface of the upper die base 22 with a bolt 24, and a Wear plate 25 fixed to the loxer inclined surface of the support block 23with a bolt 26, and the slide caa 27 is held by a guide plate (not illustrated) and slid on the lower surface of the wear plate 25. On the top surface of the slide cam 27, the negative angle forming portion 28 is fixed With a bolt 29, at the opposite position to the groove 10 of the edge portion rotating cam 3 of the slide cam 27.
On the top inclined surface of the slide cam 27, a support plate 129is fixed xith a bolt 30, and betxeen this support plate 129 andthe supportplate fixed to the support block 23, a coil spring 32 is compressedly mounted to energize the slide cam 27 to the outward direction of the die.
The said coil spring 32 is mounted in the externally fitted form to the positioning pin 33 screwed into the support plate 31, and the tip end of the said positioning pin 33 allows a stopping plate 34 fixed to the side surface opposite to the support plate 31 to pass through_ When the upper die 21 rises, the slide cam 2? moves outwards of the die until the support plate 129 comes in contact xith the stopping plate 3u by the energizing force of the coil spring 32.
Though it is not illustrated, in order to stably support the work W, the positioning member of the work H is mounted to the lower die 5, and to the upper die 21, as described in the conventional example, a pad for pressurizing the work W is mounted to the lower die 5, but as these would make the illustration complicated and essential points of this invention difficult to understand, the positioning member and the pad are omitted.
At the center portion of the work W, the small-dianeter center rotating can portion 2 is shown with an alternate long and two short dashes line, and others are nearly identical to the large-diameter rotating cam portion.
Next description will be made on the operation of the thin sheet forming _g_ 2'96929 dies.
The condition shown in Fig. 3 is the bottom dead center condition and corresponds to Fig. 7 of the conventional example.
In this invention, it is not illustrated but as shown in Fig. 5 of the conventional example, the upper die 21 is located at the top dead center, when the work W is loaded to the work support portions 20 of the lower die 5. In this event, the center rotating cam 4 is rolled to retract by the air cylinder 11.
Next, as shown in Fig. 6 of the conventional example, in the upper die 21, the inclined surface ~1 of the slide cam 27 comes in contact with the rolling plate 17 without allowing the slide cam 27 to interfere with the negative angle forming portion 16 of the small-diameter center rotating cam 2 and large-diameter edge portion rotating cam portion 3, causing the small-diameter center rotating cam 2 and large-diameter edge portion rotating cam portion 3 to rotate counterclockwise (the rolling direction is reversal in the conventional example and this embodiment).
As the upper die 21 further continues to descend, the slide cam 27 energized in the outward direction of the dies resist against the energizing force of the coil spring 32 and moves to the right in the lateral direction by the action of the cam, and enters the condition shown in Fig. 7 of the conventional example, that is, the condition shown in Fig. 3, and the negative angle forming portion 16 of the rolled small-diameter center rotating cam portion 2 and large-diameter edge portion rotating cam 3 cooperate with the negative angle forming portion 28 of the slide cam 27 to negative-angle form the work W.
After negative-angle forming, the upper die 21 begins to ascend. The slide cam 27 is energized in the outward direction of the dies by the coil spring 32, moves to the left as shown in Fig. 8 of the conventional example, and ascends without interfering with the negative-angle formed work W.
On .the other hand, when the restrained slide cam 27 ascends and the air cylinder 11 contracts the piston rod 15, the small-diameter center rotating can portion 2 and the large-diameter edge portion rotating cam portion 3 rotate in the left direction to enable the removal of the xork B xithout interfering xith the negative angle forming portion 16 of the small-diameter center rotating cam portion 2 and the large-diameter edge portion rotating cam portion 3, xhen the negative-angle formed work W is removed from the lower die 5.
This invention is a forming die with a forming portion to achieve a negative angle when the second die is moved in the straight line to abut the first die for forming, and in the thin sheet forming dies in which a cylindrical rotating cam xith a groove formed in the axial direction is rotatably mounted to the first die, a negative angle forming portion is formed in the groove edge portion of the rotating cam, a slide cam with the negative angle forming portion is mounted to the second die in such a manner to be opposite to the said rotating cam, an automatic return device for rotating and retracting the rotating can to enable the removal of the xork from the first die after forming is mounted to the first die, because it is a thin sheet forming die designed to process an excessively bent negative angle forming portion xith one rotating cam equipped xith a plurality of cylindrical rotating cam portions xith varying diameters, it becomes possible to form an excessively bent negative angle forming portion xith one forming die, to reduce the number of processes, and to improve the processing accuracy.
In particular, the thin sheet forming die according to this invention is suited for negative-angle forming the protruded circular arc curved portion as seen from the plane. This is because the flange to be formed becomes a shrinkage flange as it is protruded and tends to generate xrinkles at the time of forming, requiring bottom pushing processing. In this invention, because the rotating cams are formed integrally, bottom pushing forming is possible in high accuracy.
Because an excessively bent negative forming section is formed into a plurality of diameter portions in this invention, it is possible to give 2'96929 consideration to prevent the negative-angle forming portions of the rotating cams from being excessively acute, and the rotating cams are free of short strength.
In addition, when a plurality of rotating cams are used, their end faces may interfere with one another at the joints of adjoining rotating cams when the rotating cams are rotated, but the dies according to this invention are completely free of such interference because in this invention, one rotating cam is used.
Claims (10)
1. A pressing apparatus comprising a lower die having a supporting portion for supporting a metal sheet material to be worked and an upper die movable in a path downwardly and linearly with respect to said lower die to abut on the material to be worked, so as to shape the material to be worked, said pressing apparatus further comprising:
at least one cylindrical member having an outer surface being rotatably disposed in said lower die adjacent said supporting portion, said cylindrical member having a groove opening to said outer surface and extending along its axial extent and a recess forming portion formed at an edge portion of said groove near to said supporting portion and stepped inside from said path of said upper die;
a slide cam having a recess forming portion and slidably arranged on said upper die for confronting said cylindrical member; and an automatic return element, provided in said lower die, for rotationally returning said cylindrical member to a starting position at which said material after being shaped can be taken out from said lower die, wherein said material to be worked is placed on said supporting portion of said lower die and is shaped by said recess forming portion of said cylindrical member by sliding movement of said recess forming portion of said slide cam, and thereafter said cylindrical member is rotationally returned to said starting position by said automatic return element so that the worked material can be taken out from said lower die, and wherein said at least one cylindrical member comprises a plurality of cylindrical members in varying diameters.
at least one cylindrical member having an outer surface being rotatably disposed in said lower die adjacent said supporting portion, said cylindrical member having a groove opening to said outer surface and extending along its axial extent and a recess forming portion formed at an edge portion of said groove near to said supporting portion and stepped inside from said path of said upper die;
a slide cam having a recess forming portion and slidably arranged on said upper die for confronting said cylindrical member; and an automatic return element, provided in said lower die, for rotationally returning said cylindrical member to a starting position at which said material after being shaped can be taken out from said lower die, wherein said material to be worked is placed on said supporting portion of said lower die and is shaped by said recess forming portion of said cylindrical member by sliding movement of said recess forming portion of said slide cam, and thereafter said cylindrical member is rotationally returned to said starting position by said automatic return element so that the worked material can be taken out from said lower die, and wherein said at least one cylindrical member comprises a plurality of cylindrical members in varying diameters.
2. A pressing apparatus comprising:
an upper die and a lower die, said upper die and said lower die being movable .relative to one another;
said lower die including a workpiece support, said lower die further including a cylindrical member rotatable with respect to said workpiece support, said cylindrical member including first and second cylindrical member portions having different diameters and rotatable about a common axis of rotation, said first and second cylindrical member portions having an axially extending groove therein including first forming portions; and said upper die including a slide cam slidable thereon, said slide cam having second forming portions thereon at locations opposed to said first forming portions, whereby displacement of said upper die toward said lower die causes said slide cam and said second forming portions to move toward said first forming portions of said cylindrical member portions to thereby shape a portion of a workpiece which is located between said first and second forming portions.
an upper die and a lower die, said upper die and said lower die being movable .relative to one another;
said lower die including a workpiece support, said lower die further including a cylindrical member rotatable with respect to said workpiece support, said cylindrical member including first and second cylindrical member portions having different diameters and rotatable about a common axis of rotation, said first and second cylindrical member portions having an axially extending groove therein including first forming portions; and said upper die including a slide cam slidable thereon, said slide cam having second forming portions thereon at locations opposed to said first forming portions, whereby displacement of said upper die toward said lower die causes said slide cam and said second forming portions to move toward said first forming portions of said cylindrical member portions to thereby shape a portion of a workpiece which is located between said first and second forming portions.
3. The pressing apparatus according to claim 2, wherein said cylindrical member further includes a slide cam engaging member extending outwardly therefrom which is engagable by said slide cam to cause said cylindrical member to rotate.
4. The pressing apparatus according to claim 2, further including a return device for returning the cylindrical member to a position where the workpiece may be removed from the lower die.
5. The pressing apparatus according to claim 4, wherein said return device comprises an air cylinder.
6. The pressing apparatus according to claim 5, wherein said air cylinder includes a rod having a distal portion pivotally attached to a connecting member extending from said cylindrical member.
7. The pressing apparatus according to claim 6, wherein said connecting member extends through an opening provided in a lower wall of said lower die.
8. The pressing apparatus according to claim 7, wherein said cylindrical member further includes a slide cam engaging member extending outwardly therefrom which is engagable by said slide cam to cause said cylindrical member to rotate.
9. The pressing apparatus according to claim 2, wherein said first and second cylindrical member portions include a central portion having a first diameter, and a pair of end portions having a second diameter larger than said first diameter.
10. A pressing apparatus comprising:
an upper die and a lower die, said upper die and said lower die being movable relative to one another;
said lower die including a workpiece support, said lower die further including a cylindrical member rotatable with respect to said workpiece support, said cylindrical member including a central portion having a first diameter, and a pair of end portions having a second diameter larger than said first diameter, said central portion and said end portions rotatable about a common axis of rotation, said central portion and said end portions having an axially extending groove therein including first forming portions;
a return device for returning the cylindrical member to a position where the workpiece may be removed from the lower die, said return device comprising an air cylinder, said air cylinder including a rod having a distal portion pivotally attached to a connecting member extending from said cylindrical member through an opening provided in a lower wall of said lower die;
said upper die including a slide cam slidable thereon, said slide cam having second forming portions thereon at locations opposed to said first forming portions;
said cylindrical member further including a slide cam engaging member extending outwardly therefrom which is engagable by said slide cam to cause said cylindrical member to rotate, whereby displacement of said upper die toward said lower die causes said slide cam and said second forming portions to move toward said first forming portions of said central portion and said end portions to thereby shape a portion of a workpiece which is located between said first and second forming portions.
an upper die and a lower die, said upper die and said lower die being movable relative to one another;
said lower die including a workpiece support, said lower die further including a cylindrical member rotatable with respect to said workpiece support, said cylindrical member including a central portion having a first diameter, and a pair of end portions having a second diameter larger than said first diameter, said central portion and said end portions rotatable about a common axis of rotation, said central portion and said end portions having an axially extending groove therein including first forming portions;
a return device for returning the cylindrical member to a position where the workpiece may be removed from the lower die, said return device comprising an air cylinder, said air cylinder including a rod having a distal portion pivotally attached to a connecting member extending from said cylindrical member through an opening provided in a lower wall of said lower die;
said upper die including a slide cam slidable thereon, said slide cam having second forming portions thereon at locations opposed to said first forming portions;
said cylindrical member further including a slide cam engaging member extending outwardly therefrom which is engagable by said slide cam to cause said cylindrical member to rotate, whereby displacement of said upper die toward said lower die causes said slide cam and said second forming portions to move toward said first forming portions of said central portion and said end portions to thereby shape a portion of a workpiece which is located between said first and second forming portions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2196929 CA2196929C (en) | 1997-02-06 | 1997-02-06 | Thin sheet forming dies |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2196929 CA2196929C (en) | 1997-02-06 | 1997-02-06 | Thin sheet forming dies |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2196929A1 CA2196929A1 (en) | 1998-08-06 |
| CA2196929C true CA2196929C (en) | 2004-11-23 |
Family
ID=4159846
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2196929 Expired - Lifetime CA2196929C (en) | 1997-02-06 | 1997-02-06 | Thin sheet forming dies |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2196929C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102101139A (en) * | 2010-12-02 | 2011-06-22 | 奇瑞汽车股份有限公司 | Tapered wedge rotating mechanism |
| CN102380549A (en) * | 2011-09-26 | 2012-03-21 | 奇瑞汽车股份有限公司 | Novel rotary inclined wedge mechanism |
-
1997
- 1997-02-06 CA CA 2196929 patent/CA2196929C/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102101139A (en) * | 2010-12-02 | 2011-06-22 | 奇瑞汽车股份有限公司 | Tapered wedge rotating mechanism |
| CN102101139B (en) * | 2010-12-02 | 2012-08-22 | 奇瑞汽车股份有限公司 | Tapered wedge rotating mechanism |
| CN102380549A (en) * | 2011-09-26 | 2012-03-21 | 奇瑞汽车股份有限公司 | Novel rotary inclined wedge mechanism |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2196929A1 (en) | 1998-08-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0858847B1 (en) | Thin sheet forming dies | |
| EP0857525B1 (en) | Thin sheet forming dies | |
| EP0699489B1 (en) | Forming die for forming thin plate | |
| EP1535674B1 (en) | Negative-angle press-working die | |
| WO2006117896A1 (en) | Roll hemming method and roll hemming apparatus | |
| CN1295895A (en) | Mould for forming negative angle | |
| JP2002263753A (en) | Negative angle forming die | |
| JP3492642B2 (en) | Rotating cam moving device of negative angle forming die | |
| CA2196929C (en) | Thin sheet forming dies | |
| US5507165A (en) | Hemming fixture | |
| US20040007043A1 (en) | Negative angle forming type rotary cam moving apparatus | |
| EP0427886A1 (en) | Die for negative angle forming | |
| CA2196928C (en) | Thin sheet forming dies | |
| JP2866629B2 (en) | Thin plate mold | |
| JP3196615B2 (en) | Press mold | |
| JPH08256B2 (en) | Mold for thin plate | |
| KR100468532B1 (en) | Thin sheet forming dies | |
| JPS60166122A (en) | Method of forming sheet and its forming die | |
| CN217044076U (en) | Side wall planking plastic mechanism | |
| JPH031084B2 (en) | ||
| CN1110382C (en) | Thin sheet forming dies | |
| CN211868742U (en) | Press slide block guiding device | |
| CN1099923C (en) | Thin sheet forming dies | |
| KR100468533B1 (en) | Thin sheet forming dies | |
| KR100242672B1 (en) | Method for making thin plate and its die |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |
Effective date: 20170206 |