JP2000051978A - Flange lifter for press die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a lift stroke when releasing is executed by pushing up a flange part of a work from a lower die by a flange lifter. SOLUTION: A flange lifter is provided with an engaing means 20 comprising a vertically movable rod 11 pushed down by descending an upper die 3, a float 12 which descends to the lowest limit position integrally with the vertically movable rod 11, a casing 14 supporting the float 12, a spring 15 to energize the vertically movable rod 11 with normally upward elastic force, and a rigid ball 22 to properly engage the vertically movable rod 11 with the float 12. At the time when the upper die 3 bends the peripheral edge part of a work 1, the float 12 is made to stand still at the lowest limit position and only the vertically movable rod 11 is made to descend. When the bending the work 1 is finished and the upper die 3 ascends to a bending starting position, the float 12 is made to ascend and pushs up a flange part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flange lifter for a press die used for releasing a flange portion formed by bending a peripheral portion of a sheet metal work at a right angle with a press die. .

[0002]

2. Description of the Related Art In order to prevent the work from sticking to the lower mold after the peripheral edge of the sheet metal work is press-formed at right angles by the lower mold having the press mold fixed and the upper mold moving up and down. The flange lifter used is configured to move up and down in conjunction with the upper die, and a conventional example thereof will be described with reference to FIGS.

FIG. 8A shows a part of a press die before press forming and a flange lifter 30. The press die includes an upper die 3 that moves up and down and a lower die 2 at a fixed position. The upper die 3 moves up and down in cooperation with the pad 4, and on the lower surface of the upper die 3, a curved blade 5 for directly bending the peripheral portion of the work 1 and a lifter pressing pin 6 are fixed. The work 1 is placed on the lower mold 2, and the periphery of the work 1 slightly protrudes outward from the upper surface of the lower mold 2.

The flange lifter 30 includes an elevating rod 31 that moves up and down in conjunction with the upper die 3, a cylindrical casing 33 that supports the elevating rod 31 so as to be able to move up and down, a lower end of the elevating rod 31, and a bottom of the casing 33. The coil spring 34 is inserted between the coil springs. A lift block 32 is fixed to the upper end of the lifting rod 31, and the lift block 32
Moves up and down along the side surface of the lower mold 2. FIG. 8 (A)
The lifting rod 31 in the normal state shown in FIG.
4 and is stopped at a predetermined upper limit position. At this time, the upper surface of the tip of the lift block 32 is located immediately below the peripheral portion of the work 1.

In the state shown in FIG. 8A, the upper mold 3 and the pad 4 are lowered, and the pad 4 presses the work 1 against the lower mold 2 as shown in FIG. The pin 6 pushes down the lifting rod 31, and the curved blade 5 comes into contact with the periphery of the work 1. Further, as shown in FIG. 8 (C), the upper die 3 descends, and the curved blade 5 bends the peripheral portion of the work just below at a substantially right angle to form the flange portion 1 ′, and the lifter presser pin 6 moves the lifting rod 3.
Press 1 down to the lower limit. The upper die 3 descends to a lower limit position where the lower end of the curved blade 5 reaches the lower end of the flange portion 1 ′, and the flange portion 1 ′ formed by bending is pressed against the side surface of the lower die 2.

Next, as shown in FIG. 9 (A), the state where the work 1 is pressed against the lower mold 2 by the pad 4 is maintained, and only the upper mold 3 starts to rise. 3
1 rises due to the elasticity of the coil spring 34. When the lower end of the curved blade 5 rises to the upper surface position of the work 1, a predetermined gap G is formed between the upper end of the lift block 32 of the lifting rod 31 and the lower end of the flange portion 1 '. When the pad 4 starts to rise together with the upper mold 3 from the time when the gap G is formed and rises by the stroke amount of the gap G, the upper end of the lift block 32 is positioned at the lower end of the flange portion 1 'as shown in FIG. Abut 9B, the upper die 3 and the pad 4 are raised to the upper limit position, and as shown in FIG. 9C, the lifting rod 31 is raised to the upper limit position by the elasticity of the coil spring 34, and the lift block 32 is lifted. Pushes up the flange portion 1 ′ to release the work 1 from the lower mold 2.

When the gap G is reduced to 0 in the state shown in FIG. 9A, the lift block 32 is simultaneously raised by the upper die 3 and the lifting rod 31 from the state where the pad 4 still presses the work 1 against the lower die 2. Starts to push up the flange portion 1 ′, and the work 1 may be deformed. Therefore, a small predetermined gap G is provided in order to prevent such a workpiece release error, and the lift block 32 pushes up the flange portion 1 ′ at a timing when the pad 4 separates from the workpiece 1.

[0008]

Problems to be Solved by the Invention FIGS. 8B to 8C
The lowering stroke of the upper mold 3 which reaches the above needs only to have a bending stroke S corresponding to the height of the flange portion 1 'which is originally bent right below. However, when the height of the flange portion 1 ′ is different depending on the peripheral edge position in the same work, the bending stroke S must be adjusted to the longer bending stroke S. Then, the lift stroke L 'of the flange lifter 30 must be set in accordance with the maximum bending stroke of the work.

For example, as shown in FIG. 10A, when a workpiece 1a having only a flange portion 1'a with a short bending stroke Sa is formed by bending, the gap Ga is set to a minimum in all the lift blocks 32. Thus, the flange 1′a can be released from the mold as shown in FIG. However, if the same workpiece 1a has at least one flange portion 1'b having a large bending stroke Sb as shown in FIG. 10C, the minimum gap Ga as shown in FIG.
When the mold is released from the state in which the curved blade 5 is not separated from the flange portion 1'b, a mistake in releasing the flange portion 1'b occurs when the lift block 32 rises by the minimum gap Ga. .

Therefore, as shown in FIG. 10E, when the flange portion 1'b of the workpiece 1a is bent by the curved blade 5, the gap Gb with the lift block 32 is set to be equal to or more than the maximum bending stroke Sb. The same clearance G is set in the flange portion 1'a having the short bending stroke Sa.
b is set so that the mold release of all the flange portions 1'a and 1'b is normally performed. Since the long stroke of the lift block 32 is ensured even for the short flange portion 1'a, there is a problem that the installation position and the operation range of other press equipment are restricted.

It is an object of the present invention to provide a flange lifter for a press die in which the lift stroke of each flange lifter can be set to a necessary minimum even if the flange bending stroke of the upper die becomes large.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, according to the present invention, a flange is formed by bending a peripheral portion of a work with a descending upper die and a fixed lower die at a substantially right angle along a side surface of the lower die. In a flange lifter which pushes up a bent flange portion on a side surface of the lower die of a press die for forming a part and releases a work from the lower die, an elevating rod which is pushed down by a descending upper die, and this elevating rod A float that is slidably inserted up and down on the outer periphery of the lower die together with the lifting rod to a position where the lower upper die contacts the peripheral edge of the work before bending, and a float fixed to the side of the lower die And a spring material that constantly urges the elevating rod upwardly with respect to the casing, and an elevating rod until the descending upper die contacts the peripheral edge of the workpiece before bending. Engage the float When the descending upper mold starts to bend the periphery of the work, the engagement is released by the lowering force of the upper mold, and only the lifting rod is lowered. When the bent upper die starts to rise,
The elevating rod is raised by a spring material to follow this ascending movement, and ascends to a position where the elevating rod is engaged with the float by the engaging means, and when the elevating rod is engaged with the float by the engaging means, it is integrated with the elevating rod. The float is raised, and the bent flange of the work is pushed up by the rising float.

Here, the lifting rod and the float are integrally lowered by the engaging force of the engaging means until the descending upper die comes into contact with the peripheral portion of the work, and the upper die bends the peripheral portion of the work to form the flange portion. Until the bend is formed, only the lifting rod is lowered and the float stops. Therefore, the float lowering stroke can be set to the shortest stroke necessary for the length of the corresponding flange portion without being restricted by the upper mold lowering stroke.

In the present invention, the engaging means may include an engaging hole formed in a radial direction in a cylindrical portion of the float which is vertically slidably fitted between the lifting rod and the casing. A rigid ball loosely fitted in the engaging hole with a diameter larger than the axial length of the engaging hole and a rigid ball formed on a part of the outer periphery of the lifting rod and protruding from the inner end of the float engaging hole are detachably engaged. It is preferable to form an engaging groove and a relief groove formed on the inner periphery of the casing and removably engaged with a hard sphere protruding from the outer end of the engaging hole of the float.

In the case of this engaging means, when the lifting rod and the float are at the upper limit position, the hard sphere engages with the engagement groove of the lifting rod, and the lifting rod and the float are pushed down by the lowering of the upper die, so that the upper die is lowered. When the ball is lowered to a position where it comes into contact with the peripheral portion of the workpiece, the hard sphere escapes to the escape groove of the casing to disengage the lifting rod from the float, and thereafter only the lifting rod is lowered.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 7 show a flange lifter in which the present invention is applied to the press die shown in FIG. 8, and the same or corresponding parts of the press die are denoted by the same reference numerals, to avoid repeated description.

A flange lifter 10 shown in FIG. 1 includes an elevating rod 11 pressed down by a descending upper die 3 and an elevating rod 1.
1, a cylindrical float 12 inserted around the outer periphery of the float 1, a cylindrical casing 14 inserted around the outer periphery of the float 12,
A spring material, for example, a coil spring 15 is compression-inserted between the bottom of the casing 14 and the lower surface of the lifting rod 11. A lift block 13 for pushing up a flange is fixed to an upper end of the float 12. Lift rod 11 and float 1
An engagement means 20 is provided between the casing 2 and the casing 14 to appropriately and integrally engage the lifting rod 11 and the float 12.

As shown in FIG. 4A, for example, the lifting rod 11 has a small-diameter rod upper part 11a and a large-diameter rod lower part 1a.
1b, one engagement groove 23 of the engagement means 20 is formed in a part of the outer periphery of the rod lower part 11b. Engagement groove 23
Is formed in a V-shaped cross section by an upper inverted conical tapered surface and a lower conical tapered surface.

The float 12 has a cylindrical float upper part 1.
2a and the lower float 12b, and the upper float 1
The upper rod 11a of the lifting rod 11 is slidably inserted into the upper and lower rods 2a, and the lower rod 11 is inserted into the lower float 12b.
b is slidably inserted up and down. Float lower part 12b
One engaging hole 21 of the engaging means 20 at a part of the predetermined height of
Is formed, and a hard sphere 22 is inserted into the engagement hole 21.
The engagement hole 21 is a round hole penetrating a part of the float lower part 12b in the radial direction as shown in FIG. As shown in FIG. 3A, the diameter D of the hard sphere 22 is slightly larger than the thickness t of the lower float portion 12b, and therefore, a part of the hard sphere 22 is engaged from one of the two ends of the engagement hole 21. put out.

The casing 14 is a cylinder having an open top and a bottom.
The inner peripheral surface has a large-diameter inner peripheral upper portion 14a and a small-diameter inner peripheral lower portion 1a.
4b, the float 12 is slidably inserted in the upper part 14a of the inner periphery so as to be vertically slidable.
The step surface 14c at the boundary of b is formed as a stopper surface that determines the lower limit position of the float 12. Also, the inner peripheral upper part 14a
Is formed at one of the fixed positions. The relief groove 24 is a V-shaped cross section similar to the engagement groove 23. When the rigid sphere 22 comes to the groove position, a part of the rigid sphere 22 enters the relief groove 24 as shown in FIG.

At the upper end of the casing 14, a retaining member 16 for fixing the upper limit position of the float 12 is fixed. For example, as shown in FIG.
a part of the outer periphery of the flat surface 17
The step 18 is formed at the boundary between the and the lower part 12b of the float. The lifting rod 11 is inserted into the float 12, a hard ball 22 is inserted into the engagement hole 21 of the lower float 12 b, and the lower float 12 b is inserted into the casing 14 via the coil spring 15 as shown in FIG. The retaining member 16 is positioned so as to be in contact with the flat surface 17 of 12 a and fixed to the upper end of the casing 14.

FIG. 1 shows a normal state in which the lifting rod 11 and the float 12 are pushed up to the upper limit position by the elastic force of the coil spring 15 and are stationary. At this time, the engaging hole 21 of the float lower portion 12b is located above the clearance groove 24 of the casing 14, and the rigid sphere 22 of the engaging hole 21 is pressed by the inner peripheral surface of the casing above the clearance groove 24, and the rigid sphere 22 moves up and down. By fitting into the engagement groove 23 of the rod 11, the lifting rod 11 and the float 12 are integrally engaged.

The above-described flange-up operation of the flange lifter 10 will be described with reference to FIGS.

As shown in FIG. 5A, the work 1 is set on the lower mold 2 when the flange lifter 10 is at the normal position. At this time, the upper surface of the tip of the lift block 13 of the float 12 is located near the lower surface of the peripheral portion of the work 1. In the state of FIG. 5A, the upper mold 3 and the pad 4 start descending, and the pad 4 presses the work 1 as shown in FIG. 5B, and the lifter pressing pin 6 of the upper mold 3 is moved up and down by the lifting rod. After pressing down 11, the curved blade 5 comes into contact with the upper surface of the peripheral portion of the work 1.

At the beginning of the lowering of the lifting rod 11, since the float 12 is engaged with the float 12 by the hard sphere 22, the lifting rod 11 and the float 12 are lowered integrally. Float 12
Is lowered in the casing 14 and the lower end abuts on the cross section 14c, the lowering stops, and the engagement hole 21 of the float 12 faces the escape groove 24 of the casing 14 at this lower limit position. As a result, the rigid ball 22 of the engaging hole 21 is pushed by the tapered surface of the engaging groove 23 of the elevating rod 11 to be lowered and fits into the relief groove 24, and the rigid ball 22 comes off the engaging groove 23 and the float 12 The engagement of the lifting rod 11 is released. The disengagement is performed at the timing when the curved blade 6 comes into contact with the peripheral portion of the work, and the bending of the peripheral portion of the work 1 is started.

In the state shown in FIG. 5B, the upper mold 3 is lowered and
As shown in (C), the peripheral portion of the work 1 is bent just below to form the flange portion 1 '. The descending stroke of the upper mold 3 during this time is the bending stroke S of the flange portion 1 '. The lowering of the upper die 3 causes the lifting rod 11 to move the coil spring 1
5 is compressed and lowered by the same stroke S, and the float 12
Remains stationary.

Next, as shown in FIG. 6A, the upper die 3 starts to rise, and the lifting rod 11 rises with the elasticity of the coil spring 15 following this rise. Upper die 3 is shown in FIG.
At the time when it has risen to the same height as (B), the lifting rod 11
Reaches the position of the engagement hole 21 of the float 12, the lifting rod 11 slightly pushes up the float 12, and the clearance groove 24 of the casing 14 presses the hard sphere 22 to engage the engagement groove 2
3 and the lifting rod 11 and the float 12 are engaged again. Thereafter, the pad 4 and the upper mold 3 are raised, the lifting rod 11 and the float 12 are raised to the upper limit position by the elasticity of the coil spring 15, and the lift block 13 is moved to the flange portion 1 'as shown in FIG. To release the work 1 from the lower mold 2.

When lifting the flange portions 1 'of a plurality of types of workpieces 1 by the above-described flange lifter 10, the substantial lift stroke L of the flange lifter 10 is set as follows. As shown in FIG. 7A, the maximum value of the bending stroke S of the flange portion 1 'of the work 1 is shown in FIG.
If the maximum bending stroke Sb is the same as 0 and the gap between the lower end of the flange portion 1 'and the lift block 13 when the curved blade 5 bends the flange portion 1' to the end is G, which is a necessary minimum value close to 0, The lift stroke L may be set to (Sb + G). FIG. 7B shows the state in which the upper die 3 and the lifting rod 11 rise from the state shown in FIG.
Shows the state before pushing up the flange portion 1 ′. From this state, the pad 4 rises and the lift block 13 normally pushes up the flange portion 1 ′.

The lift stroke L in the embodiment of the present invention is about half of the lift stroke L 'shown in FIG. Therefore, as the maximum value of the bending stroke of the peripheral portion of the work increases, the effect of reducing the lift stroke and the size of the flange lifter increases.

[0030]

According to the present invention, in a short flange portion of a work having bent flange portions having different lengths,
When the upper die bends the edge of the work directly below, the float is stopped and only the lifting rod is pushed down.The flange of the work is formed and the upper die rises to the height of the work, and then the float is lifted together with the lifting rod. Since the flange can be pushed up by lifting it, the lift stroke of the flange lifter can be shortened to the bending stroke of the corresponding flange, and the compactness and compactness that does not significantly restrict the installation of peripheral equipment etc. A low-cost flange lifter can be provided.

Further, by applying a fitting structure of a hard sphere and a groove to the engagement means for appropriately engaging the lifting rod and the float,
It is possible to provide a flange lifter having a simple structure and a built-in engagement means with stable operation.

[Brief description of the drawings]

FIG. 1 is a sectional view of a flange lifter showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along line XX of FIG.

3A is a partially enlarged sectional view of the flange lifter of FIG. 1, and FIG. 3B is a partially enlarged sectional view during operation.

4A is an exploded side sectional view of a lifting rod and a float in the flange lifter of FIG. 1, and FIG. 4B is a plan view of the float.

FIG. 5 is a sectional view showing each operation of bending the work of the flange lifter.

FIG. 6 is a sectional view showing each operation of the flange lifter after bending the work.

FIG. 7 is a sectional view for explaining a lift stroke of the flange lifter in FIG. 1;

FIG. 8 is a cross-sectional view showing each operation of bending a work of a conventional flange lifter.

FIG. 9 is a cross-sectional view showing each operation of a conventional flange lifter after bending a work.

FIG. 10 is a cross-sectional view illustrating a lift stroke of a conventional flange lifter.

[Explanation of symbols]

 Reference Signs List 1 work 1 'flange portion 2 lower die 3 upper die 4 pad 10 flange lifter 11 lifting rod 12 float 14 casing 15 spring material (coil spring) 20 engaging means 21 engaging hole 22 rigid ball 23 engaging groove 24 relief groove

Claims (2)

[Claims] 1. A press die for forming a flange by bending a peripheral portion of a work with a descending upper die and a fixed lower die at a substantially right angle along a side surface of the lower die. A flange lifter that lifts a bent flange part to release a work from a lower die, and is a lift rod that is pushed down by a descending upper die, and is fitted slidably up and down on the outer periphery of the lift rod. The upper die that descends with the lifting rod to a position where it comes into contact with the peripheral edge of the work before bending, the casing fixed to the side of the lower die and supporting the float so that it can move up and down, and the casing On the other hand, the spring material that constantly urges the lifting rod upward and the upper die that descends engages the float with the lifting rod until the upper die that descends contacts the peripheral edge of the work before bending. Start bending the perimeter The upper die is provided with engaging means for releasing the engagement by the lowering force of the upper die so that only the elevating rod is lowered, and when the upper die having bent the peripheral portion of the work starts to ascend, the upper die follows the upward movement. The lifting rod is raised by a spring material, and the lifting rod is raised to a position where it is engaged with the float by the engagement means. When the lifting rod is engaged with the float by the engagement means, the float is raised integrally with the lifting rod. A flange lifter for a press die, wherein a bent flange portion of a work is pushed up by a rising float. 2. An engaging hole formed in a radial direction in a cylindrical portion of a float inserted vertically slidably between a lifting rod and a casing, and a shaft of the engaging hole. A rigid ball loosely fitted in the engagement hole with a diameter larger than the direction length, and an engagement groove formed on a part of the outer periphery of the elevating rod and removably engaged with the rigid ball projecting from the inner end of the engagement hole of the float. 2. An escape groove formed on an inner periphery of the casing and protruding from an outer end of an engagement hole of the float, the escape groove being removably engaged with the relief ball. Flange lifter.