JP2003225721A - Hemming system, and hemming process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hemming system favorable for works of small lot multi- production in which the lower die setup accompanied by the change of the kind of the works can be performed with excellent workability. <P>SOLUTION: In this hemming system in which a versatile tool 40 with a lower die 10 mounted thereon is positioned on and held by a working stage 20, and a peripheral edge part of the work 1 positioned on and held by the lower die 10 is hemmed by a robot arm 30, a plurality of kinds of exclusive lower dies 10 are available for a plurality of kinds of works 1, and the versatile tool 40 is commonly used for the plurality of kinds of lower dies 10. Cramp mechanisms 50 are installed at a plurality of parts on the versatile tool 40 in a positionally movable manner, and in a vertically opening/closing manner, and each cramp mechanism 50 is closed, and presses a plurality of arbitrary parts of the peripheral part of the work 1 on the lower die 10 to clamp the work. The robot arm 30 is started, the peripheral edge part of the work 1 is hemmed by a hemming blade 33 at the tip, and the robot arm 30 controls the opening/closing operation of the cramp mechanism 50 accompanied by this hemming operation. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hemming system for bending a peripheral edge of a sheet metal work such as an outer panel and an inner panel of an automobile door with a robot arm.

[0002]

2. Description of the Related Art A hemming process for an outer panel and an inner panel of an automobile door is performed by holding the outer panel on a lower die positioned on a work stage at a fixed position, holding the inner panel on the outer panel, and holding the inner panel on the peripheral edge of the outer panel. The flange part formed by bending it upward in advance is formed by a robot arm on the peripheral edge of the inner panel by about 90 °.
It is done by bending. The robot arm bends in sequence while applying vibration to a part of the flange part of the outer panel with a hem blade provided at the end of the arm, and presses part of the flange part of the outer panel in order with a roller at the end of the arm. There are things that you can bend.

Since the outer panel and the inner panel of an automobile door have different shapes and sizes depending on the vehicle type, a lower die used for hemming is a dedicated die adapted to the outer panel of each vehicle type. Further, during hemming, it is necessary to position the peripheral edge of the inner panel on the peripheral edge of the outer panel on the lower die and press it in a stable state. Is it an upper mold dedicated to a specific work that makes a pair with the lower mold,
A work positioning and pressing member that is commonly used for a plurality of types of works is used.

[0004]

In the case of a hemming processing system in which a pair of a lower die and an upper die dedicated to a specific work are used to position and hold the work from above and below, the type change of the lower die accompanying the type change of the work such as the outer panel (below Since it is necessary to switch both the lower mold and the upper mold dedicated to a specific work when changing molds, it takes a lot of time to change the lower molds and it takes a long time. Since it requires molds and upper molds, it is unsuitable for high-mix low-volume work of various types (multi-vehicle types).

A hemming system for pressing and holding a work on a lower mold from directly above by a work positioning pressing member is disclosed in Japanese Patent Laid-Open No. 10-249454 and the like. A work positioning and pressing member is placed directly above the so that it can be moved up and down by a specific lifting device.
At the time of workpiece positioning, the workpiece positioning pressing member is lowered to press (engage, chuck, etc.) the central portion of the workpiece excluding the peripheral portion, and the workpiece is positioned and held. This hemming system does not need to change the general work positioning and pressing member when changing the lower mold, and the lower mold can be changed with good workability.
It is suitable for work of high-mix low-volume production. However, an elevating device that supports a general-purpose work positioning and pressing member and moves it up and down has a complicated, expensive, and large structure having a plurality of columns and the like installed around the work stage. There was a problem that increased the installation space and capital investment costs.

An object of the present invention is to provide a hemming processing system which is suitable for a work of a large variety of small-quantity production, which can reduce the installation space of the whole system and the capital investment cost and can perform the lower die change with good workability. .

[0007]

According to a first aspect of the present invention, there is provided a system in which a work is positioned and held by a lower die which is positioned and held on a work stage in a fixed position, and a peripheral edge of the work is hemmed by a robot arm. A general-purpose jig that positions and holds a selected lower mold of a dedicated lower mold for multiple types of workpieces on the upper surface, and can be moved to any position on the upper surface of this general-purpose jig and installed It is installed so that it can be opened and closed in the vertical direction at several points, and has a plurality of clamp mechanisms that press the peripheral part of the work on the lower die to position and hold it in the lower die by closing operation, and hold and position the lower die. The above object is achieved by a system for positioning a general-purpose jig on a work stage.

Here, the work to be hemmed is a sheet metal such as an automobile door, and is intended for a plurality of kinds of works having different shapes and dimensions. The work is positioned in a dedicated lower mold for each type, and the peripheral edge of the work is hemmed by a hem blade or a roller at the tip of the robot arm. A lower mold dedicated to a plurality of types of works is positioned on a general-purpose jig that is commonly used by a plurality of types of lower molds. The lower mold for specific work is
It is possible to apply the existing lower die for specific work used in the existing hemming processing system. The general-purpose jig has a lower die positioning pin or the like on the upper surface, and the lower die is positioned and held on the upper surface and positioned and held on a hemming work stage at a fixed position. It is possible to perform the lower die change work performed by changing the type of work to be hemmed with the lower die and a general-purpose jig being integrated, and such lower die change operation has a constant shape and dimension. By lowering and moving the general-purpose jig with the lifting claws of the forklift, it becomes possible to easily and quickly perform the lower die change work. Also,
The lower mold can be stored while being integrated with the general-purpose jig, and by doing so, the lower mold can be stored while being protected by the general-purpose jig.

Further, the plurality of clamp mechanisms installed on the upper surface of the general-purpose jig preferably have a toggle clamp structure in which the posture when the work is directly clamped is locked. The clamp mechanism vertically opens and closes on a general-purpose jig and presses the peripheral portion of the work on the general-purpose jig to position and hold the work on the lower die during the closing operation. Therefore, the conventional work positioning and pressing member for pressing and positioning the work on the lower mold and its elevating device are not required, and the installation space of the hemming processing system and the facility investment cost can be easily reduced. The opening / closing operation of the clamp mechanism can be performed manually or automatically, and in the case of automatic opening / closing, it is also possible to automatically perform the opening / closing independently by using a drive source such as an air cylinder provided in each of the clamp mechanisms. It is desirable to automatically open and close with a robot arm in order to simplify the clamp mechanism.

According to a second aspect of the present invention, when a general-purpose jig is placed on the work stage, a guide projection for sliding and guiding the outer periphery of the general-purpose jig, and a general-purpose jig guided by the guide projection are provided. And a guide roller which comes into contact with the outer periphery of the work piece and is driven to rotate to position and hold the general-purpose jig at the final position on the work stage.

The guide projection here guides the general-purpose jig to the guide roller, and the guide roller guides while holding the general-purpose jig which is guided by the guide projection and moves to the final position. With this two-step guide of the general-purpose jig by the guide protrusion and the guide roller, even if the general-purpose jig is slightly displaced from the work stage, the general-purpose jig is always guided to a fixed position on the work stage with a smooth operation. Moreover, since the general-purpose jig is guided by the guide roller when the general-purpose jig is lifted and taken out from the final positioning position on the work stage, the general-purpose jig can be taken out with a smooth operation. Therefore, it becomes easy to carry a set of heavy objects of a general-purpose jig having the lower die positioned and held by, for example, a forklift to position and hold it on the work stage, and take it out from the work stage by the forklift. The arrangement and structure of the guide protrusions and the guide rollers on the work stage are not limited, and the guide protrusions are hollow and the guide rollers are rotatably installed therein, or the guide protrusions are located at separate locations on the work stage. It is possible to arrange the guide roller and the guide roller separately.

According to a third aspect of the present invention, there is provided a hemming method using the hemming system of the present invention, wherein a general-purpose jig having a lower die positioned and held is positioned and held on a work stage, a work is placed on the lower die, and a robot is mounted. It is characterized in that a plurality of clamp mechanisms are sequentially closed by an arm and a work is pressed to a lower die to be positioned and fixed, and a robot arm controls opening and closing of the plurality of clamp mechanisms to hemm the peripheral edge of the work.

The robot arm according to the present invention simultaneously performs hemming of the peripheral portion of the work and opening / closing of the clamp mechanism on the general-purpose jig. In other words, since the peripheral part of the work positioned on the lower die on the general-purpose jig is pressed by the clamp mechanism, when the peripheral part of the work is hemmed in order by the robot arm, the clamp mechanism in the closed clamp state The hemming process cannot be performed at the peripheral edge where is pressed by, so the hemming process cannot be performed by the robot arm. Let it continue. By appropriately repeating such a hemming operation by the robot arm and the opening / closing operation of the clamp mechanism, even if the peripheral edge of the work is partially pressed by the clamp mechanism and positioned and held, the hemming is sequentially performed by the robot arm. .

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings (FIGS. 1 to 16).

The hemming system shown in FIGS. 1 and 2 positions and holds a set of a general-purpose jig 40 and a lower die 10 on a work stage 20 which is horizontally fixed at a fixed position, and is positioned on the lower die 10. This is a system in which the peripheral edge of the held work 1 is hemmed by the robot arm 30. The lower mold 10 is a specific work-specific mold prepared for each kind of plural kinds of works 1, and the general-purpose jig 40 is the plural kinds of lower molds 1.
It is a general-purpose type that can be shared by any type of 0. The lower die 10 is positioned and held on the general-purpose jig 40, the general-purpose jig 40 holding the lower die 10 is positioned and held on the work stage 20, and the work 1 is set on the lower die 10. The clamp mechanism 50 is installed at a plurality of locations on the general-purpose jig 40,
The lower mold type setting unit 60 is installed at one location. The clamp mechanism 50 presses and clamps arbitrary plural portions of the peripheral portion of the work 1 set on the lower die 10 on the general-purpose jig 40. The lower die type setting unit 60 is for manually setting the type of the lower die 10 for specific work on the general-purpose jig 40.
The type of the lower die set here can be detected by the robot arm 30 or an optical sensor (not shown).

At predetermined plural positions on the work stage 20, guide projections 21 and guide rollers 22 for guiding and holding the general-purpose jig 40 as shown in FIG. 4 are installed. The guide protrusion 21 is fixed to the side surface of the work stage 20 and protrudes onto the work stage 20.
When the general-purpose jig 40 descends from just above 0 for positioning and mounting, the tapered inner surface of the guide protrusion 21 causes the general-purpose jig 4 to move.
It slides on the outer periphery of 0 to guide the descending direction. The guide roller 22 is built in the guide protrusion 21 and
Part of the outer periphery of 2 slightly projects from the inner surface of the lower portion of the guide protrusion 21. When the outer periphery of the general-purpose jig 40 that is guided by the guide protrusion 21 and descends contacts the part of the outer periphery of the projecting guide roller, the guide roller 22 is driven to rotate at a fixed position to move the general-purpose jig 40 on the work stage 20. Guide to the final positioning position and hold the positioning at the final position. As described above, when the general-purpose jig 40 is placed on the work stage 20, the general-purpose jig 40 is slightly displaced from the work stage 20 by positioning the general-purpose jig 40 in two steps by the guide protrusion 21 and the guide roller 22. However, good positioning is always possible. The guide roller 22 smoothes the vertical movement of the general-purpose jig 40 at the time of final positioning, and smoothes the positioning and loading operation of the general-purpose jig 40 onto the work stage 20 and the unloading operation from the work stage 20. . Therefore, the lower mold 10
It becomes easy to carry a heavy object of the general-purpose jig 40 mounted with a forklift (not shown) to position and hold it on the work stage 20.

Further, two parallel grooves 23 into which the two lifting claws of the forklift are inserted are formed on the upper surface of the work stage 20, and the general-purpose jig 40 is utilized by utilizing these grooves 23.
Is carried in and out. A robot body 31 is installed at a fixed position right next to the work stage 20, and a robot arm 30 extends in an arbitrary direction from the upper end of the robot body 31. At the tip of the robot arm 30, a processing unit 32 for sequentially hemming the peripheral edge of the work 1 is installed. The processing unit 32 includes, for example, a hem blade 33 and an air cylinder 34 that vibrates the hem blade 33 in the axial direction. In the vicinity of the work stage 20 and the robot body 31,
A safety fence 5 as shown in the sketch of FIG. 3 is installed.

The safety fence 5 is, for example, a fence in which a transparent resin plate is attached to an aluminum frame, and the shutter 5a and the safety fence door 5 are partially provided.
b, ... When the robot arm 30 is automatically activated for hemming, the shutter 5a prevents the worker from entering the safety fence 5, and when the worker tries to enter, the safety mat 5c is temporarily stopped by turning it on. When a worker enters, an emergency stop is activated by turning on the area sensor 5d installed inside the safety fence 5.
The safety fence door 5b is used for taking out a work, a lower mold, and a general-purpose jig from the work stage 20 inside the safety fence 5, and for carrying in a set of a general-purpose jig and a lower mold from the outside of the safety fence 5 to the work stage 20. Used for. Further, a lower mold stand 70 having a multi-tiered structure is installed on the floor near the safety fence 5, and a set of a general-purpose jig and a lower mold is carried into the work stage 20 from the lower mold stand 70 by a forklift.

As the lower die 10 dedicated to a specific work, the existing lower die used in the conventional hemming system can be applied as it is by removing unnecessary portions as necessary. By applying the existing product to the lower mold 10 as described above, it is possible to significantly reduce the capital investment cost. Arbitrary types of lower dies 10 having different shapes and sizes are positioned and held on a common general-purpose jig 40.

The general-purpose jig 40 is a flat metal plate,
Positioning means such as a convex portion and a concave portion (not shown) are formed between the work stage 20 and the work stage 20, and the work stage 20 is removably positioned and held on the work stage 20. The clamp mechanism 50 is installed at a plurality of positions on the upper surface of the general-purpose jig 40 so as to be positionally movable, and opens and closes vertically at the installation position. For example, FIG. 5A is a plan view in which the clamp mechanisms 50 are installed at six positions on the general-purpose jig 40, and each clamp mechanism 50 is arranged in the peripheral part of the lower mold 10 in the open unclamped state. FIG. 5 (B)
Is a plan view when the type of the lower die 10 of the general-purpose jig 40 is changed, and the position and number of the clamp mechanism 50 installed on the general-purpose jig 40 is changed according to the changed lower die 10. .
The position of the clamp mechanism 50 on the general-purpose jig 40 is changed manually or automatically. A plurality of types of clamp mechanisms 50 are prepared according to the shape dimensions of the lower mold 10 and the work 1, and an example of the structure is shown in FIGS. 6 and 7.

The clamp mechanism 50 shown in the figure is a toggle clamp. FIG. 6 shows an open unclamped state, and FIG. 7 shows a closed clamped state. The clamp mechanism 50 is a general-purpose jig 4
The toggle mechanism 52 is installed at the upper end of the support column 51 projecting from above the opening / closing lever 53 and the operating lever 54. The support column 51 is installed on the side of the lower mold 10 which is positioned and held on the general-purpose jig 40, and the opening / closing lever 53 and the operation lever 54 are arranged at the upper end of the support column 51 in the vertical direction in which they approach and separate from the lower mold 10. Open and close. Open / close lever 53
Workpiece positioning and pressing pads 56 and 57 are fixed to the tip of the, and an operation rod 55 extending in the horizontal direction is integrally formed at the tip of the operation lever 54 (see FIG. 9). Figure 6
The open / close lever 53 and the operation lever 54 in the open state are locked in a fixed posture sufficiently separated from the lower mold 10, and the open / close lever 53 in the open state in FIG. The operation lever 54 is in a locked state in a vertical fixed position in which the work lever 1 is inclined to position the work 1 on the lower die 10 and extends vertically upward. The toggle mechanism 52 automatically locks the postures of the levers 53 and 54 when they are opened and when they are closed.

When all of the plurality of clamp mechanisms 50 are open, the work 1 is manually set on the lower die 10 on the general-purpose jig 40. The work 1 is, for example, an outer panel 2 and an inner panel 3 of an automobile door, and the outer panel 2 is manually positioned and placed on a lower die 10 for exclusive use of the outer panel of one model, and the inner panel 3 is manually placed on the outer inner panel 2. Placed in. A flange portion 2a which is bent substantially vertically is formed in advance on the peripheral edge of the outer panel 2, and the peripheral edge portion of the inner panel 3 is placed on the inner peripheral edge portion of the flange portion 2a. 2a is bent about 90 ° onto the peripheral edge of the inner panel 3 by the hem blade 33 at the tip of the robot arm 30.

As shown in FIG. 6, the outer panel 2 is placed on the lower mold 10.
When the operation lever 54 is rotated upward with the toggle mechanism 52 as a fulcrum while the inner panel 3 and the inner panel 3 are positioned and held, the opening / closing lever 53 rotates upward via the toggle mechanism 52, and as shown in FIG. The pads 56 and 57 at the tip of the opening / closing lever 53 press the peripheral edge of the inner panel 3 and the peripheral area in the vicinity thereof to position and hold the inner panel 3 on the outer panel 2.

The operation lever 54 is opened and closed automatically by a dedicated lever drive source such as an air cylinder equipped in each clamp mechanism 50, or by the operation rod 5 of the operation lever 54.
5 is manually performed by a worker or automatically by the robot arm 30 using the operation rod 55. The rotational movement angle of the operating lever 54 in the open state and the closed state is about 150.
The angle is between 180 ° and 180 °, and the distance that the operating rod 55 moves from the open state to the closed state and vice versa is set sufficiently large, and the operating rod 55 is used manually or automatically by the robot arm 30. The opening / closing operation by means of is easy.

The robot arm 3 opens and closes the operating lever 54.
When automatically performed at 0, for example, as shown in FIGS. 8 (A) and 8 (B), a circular work hole 35 is formed through the hem blade 33 at the tip of the robot arm 30, and the operation lever 35 is formed in this work hole 35. This is performed by loosely fitting the operation rod 55 of 54. The opening and closing procedure is shown in FIGS. 9A to 9D, the details of which will be described later. The hem blade 33 shown in FIG.
Has work holes 35 formed at two locations above and below the
Only the holes in one place are used for opening and closing the operation lever, and the other one hole is formed as needed for the purpose of reducing the weight of the hem blade.

A clamp mechanism 50 is mounted on the general-purpose jig 40.
The lower mold type display section 60 installed together with the general-purpose jig 40
The type of the lower mold 10 positioned and held on the upper side is set by changing the form, and a specific example thereof is shown in FIGS. 10 and 11. The lower mold type display unit 60 has a cylindrical stand 61 fixed at a fixed position on the general-purpose jig 40, and one setting plate 62 horizontally fixed on the upper end of the stand 61. The same number of holes 63 as the number of types of the lower molds 10 are formed in the setting plate 62, and the protrusion 64 is fitted into any one of the holes 63 selected. For example, the hole 63 is a screw hole, and the protrusion 64 is a bolt.

Individual XY coordinates of the plurality of holes 63 and the lower die 10
A plurality of types of relationships are determined on a one-to-one basis.
The protrusion 64 is inserted into the hole 63 at one position determined by one type of the lower mold 10 positioned and held on the upper side. When the set of the general-purpose jig 40 and the lower die 10 is placed on the working jig 40, the presence or absence of the protrusion 64 at the designated coordinates on the sorting plate 62 is detected by an optical sensor (not shown) when necessary, Alternatively, as shown by the chain line in FIG. 11, the robot arm 30 causes the hem blade 33 to come into contact with the protrusion 64 and conducts a conduction check, for example. The type of the lower die 10 placed on the general-purpose jig 40 is determined based on this detection signal, and the type of the work 1 positioned and held on the lower die 10 is determined from this determination.

The hemming of the work 1 by the hemming system of the above embodiment is performed as follows.

The lower mold stand 70 shown in FIG. 3 is shown in FIG.
In the three-stage rack structure as shown in FIG. 2, two parallel grooves 72 into which the lifting claws of the forklift are inserted are formed on the bars 71 of each step, and the general-purpose jig 40 and the lower mold 10 are provided on the bars 71 of each step. A set of is placed and stored. In such a lower die storage mode using the three-tier rack, each lower die 10 is placed on the general-purpose jig 40 and stored in a protected form.
It will be easy to handle during storage and transportation. Further, even the lower mold 10 having a large thickness can be stored in three upper and lower stages, so that a storage space on the floor can be reduced.

A set of the general-purpose jigs 40 and the lower mold 10 selected from the lower mold stand 70 are taken out by a forklift, and as shown in FIG.
Then, the general-purpose jig 40 is guided by the guide projections 21 and the guide rollers 22 and positioned and held on the work stage 20. After this, the worker sets the work 1 (outer panel 2 and inner panel 3) on the lower die 10 on the general-purpose jig 40 and exits from the safety fence 5. Before the robot arm 30 hemmes the set work 1, the robot arm 30 performs the following safety confirmation operation and hem blade quality confirmation operation.

An arm position detecting device 80 and a hem blade position detecting device 90 as shown in FIG. 13 are installed near the robot main body 31 on the work stage 20, and the robot arm 30 is mounted on the tip of the robot arm 30 before starting the hemming work. The hem blade 33 is moved from the arm position detecting device 80 to the hem blade position detecting device 90. A commercially available product can be applied to the pair of detection devices 80 and 90. The arm position detection device 80 has a limit switch 81 at the upper end, and the robot arm 30 is stationary at a fixed position where the hem blade 33 pushes the limit switch 81 to turn it on. While the limit switch 81 is in the ON state, an operator inspects the equipment and works the work set on the lower mold 10. If the robot arm 30 is accidentally activated during this work to move the hem blade 33, the limit switch 81 is turned off and an emergency stop is applied.

After it is confirmed by the arm position detecting device 80 that the robot arm 30 is in the normal position, the robot arm 30 is activated to move the hem blade 33 to the hem blade position detecting device 90.
Move to. The hem blade position detection device 90 uses the hem blade 33.
It detects the amount of wear and the amount of positional deviation. For example, a laser sensor 91 as shown in FIG. 14 detects the amount of wear at a plurality of points including the flat surface at the center of the tip of the hem blade 33 and the rounded portion between the tip and the side surface. Since the hem blade 33 performs hemming using the flat surface at the center of the tip and the rounded portions at both ends thereof, if the wear amount of the flat surface at the tip or the rounded portion exceeds the allowable value, the hemming processing accuracy decreases. Therefore, the hem blade position detection device 9
If the wear amount detected at 0 is less than the allowable value, for example, 0.5 mm, the operation for the next hemming is started, and if it is 0.5 mm or more, the hem blade 33 is replaced.

After the amount of wear of the hem blade 33 is inspected by the hem blade position detection device 90, the robot arm 30 performs various confirmation operations required before hemming, such as the lower die 10.
Confirmation of the type (vehicle type) of the upper work 1, confirmation of the presence of the work 1 on the lower mold 10, and the clamp mechanism 5 around the lower mold 10.
Each operation of checking the open / closed state of 0 is performed. These confirmation operations may be automatically performed by using an optical sensor, or may be performed by a continuity check using the robot arm 30. For example, to confirm the work type on the lower die 10, the hem blade 33 is used by the robot arm 30 as described in FIG.
The projection 64 at the designated coordinates in the lower die type display section 60.
Then, it is checked whether or not there is continuity between the hem blade 33 and the protrusion 64 by contacting with. The presence / absence of the work 1 on the lower die 10 is confirmed by bringing the hem blade 33 into contact with the inner panel 1b of the work 1 by the robot arm 30 to determine whether or not there is conduction. The open / closed state of the clamp mechanism 50 may be confirmed as follows.

When setting the work 1 on the lower mold 10,
Each clamp mechanism 50 is in the open state, and the open state is maintained even after the work is set. The robot arm 30 first confirms whether or not each clamp mechanism 50 is in the open state, and then each clamp mechanism 50. The operation shifts to the open / close switching operation. That is, when the clamp mechanism 50 in the open state is switched to the closed state when the robot arm 30 is in the closed state, the robot arm 30 operates so as to close the clamp mechanism 50 when the clamp mechanism 50 is already in the closed state. Since the movement of the arm 30 may be obstructed, in order to avoid this, the robot arm 30 first confirms whether or not each clamp mechanism 50 is in the open state. This confirmation operation is shown in FIG. 9 (A) → (B) → (A).
The operation sequence is as follows.

FIG. 9A shows a substantially horizontal operation lever 54 and operation rod 55 of the clamp mechanism 50 in the open state shown in FIG.
Is shown. The hem blade 3 is provided near the tip of the operating rod 55.
3 is moved by the robot arm 30, and then FIG.
After moving the hem blade 33 forward and inserting the operation rod 55 into the central portion of one operation hole 35, the hem blade 33 is slightly moved up or down or left and right to bring the inner surface of the operation hole 35 into contact with the operation rod 55. Check whether to do or not. For example,
When the hem blade 33 and the operating rod 55 come into contact with each other, electrical conduction is established, and the initial electrical continuity check is performed at the timing when the operating rod 55 enters the central portion of the operating hole 35.
At this time, a check is made with an OFF signal indicating no continuity, and then the hem blade 33 is moved slightly up and down or left and right to operate the operation hole 3
The continuity is checked at the timing when the inner surface of 5 comes into contact with the operation rod 55, and at this time, the ON signal indicating continuity is set to check OK. By these two checks OK, it is accurately confirmed that the clamp mechanism 50 is in the open state shown in FIG.

When it is confirmed that all the clamp mechanisms 50 are in the open state, the robot arm 30 sequentially closes the clamp mechanisms 50 in the open state shown in FIG. 6 to the closed state shown in FIG. 9 (A) to 9 (D), the robot arm 30 first moves the hem blade 33 from FIG. 9 (A) to FIG.
After moving to the position of (B), the hem blade 33 is shown in FIG. 9 (C).
Is moved up to the upper limit position and the operation lever 54 is opened to a substantially vertical posture via the operation rod 55 by this upward movement. After that, as shown in FIG. 9D, the hem blade 33 is retracted to be disengaged from the operation rod 55, and an operation for closing the clamp mechanism 50 in the next open state is performed.

When the robot arm 30 sequentially closes all the clamp mechanisms 50, the robot arm 30 shifts to the hemming operation of the work 1 on the lower die 10. For example, the peripheral part of the automobile door workpiece 1 to be hemmed is shown in FIG.
When the continuous first peripheral edge AB, the second peripheral edge BC, and the third peripheral edge CD shown by 5 are provided, the robot arm 30 has the hem blade 3
3 is hemmed in steps 1 to 3 indicated by arrows in FIG. In addition, step is an edge processing, step is a prehem processing, step is a main hemming step.

The steps and the end processing of the steps are
The hem blade 33 is formed in the corner portions of the first peripheral portion AB and the second peripheral portion BC, and in the corner portions of the second peripheral portion BC and the third peripheral portion CD in order.
Move and bend the corners so that prehem processing is easier.

After the step, the first step
The peripheral portion AB is prehem processed. That is, FIG.
As shown in (A), the flange portion 2a at the periphery of the outer panel 2 which is the work 1 is about 45 ° at the tip surface of the hem blade 33.
Bending prehem processing is performed. This first peripheral portion A
The prehem processing of B is performed by temporarily opening the clamp mechanism that clamps the first peripheral edge AB, and at this time, the workpiece positioning and holding is performed by clamping the second peripheral edge BC and the third peripheral edge CD. Continued with the clamp mechanism. When the prehem processing of the step is completed, the process shifts to the step and the main hem processing of the same first peripheral edge portion AB is performed. As shown in FIG. 16 (B), this main hemming is a process in which the prehemmed flange portion 2a is pressed by the tip surface of the hem blade 33 to be superposed on the peripheral edge portion of the inner panel 3, and the first peripheral edge AB The hemming process is completed.

When the hemming of the first peripheral portion AB is completed, the robot arm 30 operates to close the clamp mechanism of the first peripheral portion AB and open the clamp mechanism of the second peripheral portion BC to be processed next. Therefore, the second peripheral portion BC is pre-hem processed in two steps, and the main hem processing is performed in steps.

When the hemming of the second peripheral edge BC is completed in step, the clamp mechanism of the second peripheral edge BC is closed and the clamp mechanism of the third peripheral edge CD is opened,
In step, prehem processing of the third peripheral edge CD is performed,
Finally, in a step, the main hemming is performed, and the hemming of the peripheral portion of the work is completed.

[0042]

According to the present invention, a lower die dedicated to a plurality of types of works is positioned on a general-purpose jig shared by a plurality of types of lower dies, and the general-purpose jig is placed on a hemming working stage. Positioning and holding is performed, and the peripheral part of the work on the lower mold is clamped by the clamp mechanism on the general-purpose jig, so the lower mold change work that changes the lower mold by changing the type of work to be hemmed It can be done by moving a general-purpose jig integrated with the lower mold with a forklift, etc., and the lower mold is protected by the general-purpose jig during this lower mold change work and storage of the lower mold, making it easier to handle the lower mold. Lower mold change work and lower mold storage work can be performed easily and quickly. In addition, the clamp mechanism on the general-purpose jig can be a small one with a simple structure that only partially presses the peripheral part of the work on the lower mold, and the clamp mechanism can be applied to multiple types of lower molds and works. Because it can be applied
It is possible to provide a hemming processing system which is advantageous in terms of equipment investment and suitable for workpieces in high-mix low-volume production.

Further, the guide projections and the guide rollers on the work stage guide the general-purpose jig in two steps, and each operation of positioning and holding the general-purpose jig on the working stage and removing the general-purpose jig from the working stage. To make the positioning operation on the work stage of the lower mold and a set of general-purpose jigs accurate and easy.

[Brief description of drawings]

FIG. 1 is a side view of a hemming processing system showing an embodiment of the present invention.

2 is a plan view of the hemming processing system of FIG. 1. FIG.

FIG. 3 is a sketch drawing of the hemming processing system of FIG. 1 and its surroundings.

FIG. 4 is an enlarged side view of a portion having a guide protrusion and a guide roller of a general-purpose jig.

5A and 5B are plan views of a general-purpose jig.

FIG. 6 is a side view of the clamp mechanism in an open state.

FIG. 7 is a side view of the clamp mechanism in a closed state.

FIG. 8A is a front view of a processing unit at the tip of a robot arm, and FIG. 8B is a side view of a hem blade in the processing unit.

9A to 9D are partial perspective views showing the relationship between a hem blade and a part of a clamp mechanism.

FIG. 10 is a plan view of a lower die type display portion on a general-purpose jig.

11 is a front view of the lower mold type display portion of FIG.

FIG. 12 is a front view of a lower mold stand that stores a general-purpose jig and a set of lower molds.

FIG. 13 is a front view of an arm position detection device and a hem blade position detection device on a work stage.

FIG. 14 is a front view of a laser sensor of the hem blade position detection device.

FIG. 15 is a plan view showing an outline of a work to be hemmed.

FIG. 16A is a cross-sectional view of a workpiece when pre-hemming,
(B) is a cross-sectional view at the time of main hemming.

[Explanation of symbols]

1 work 2 outer panel 2a Flange part 3 Inner panel 10 Lower mold 20 work stages 21 Guide protrusion 22 Guide roller 30 robot arm 31 Robot body 32 processing units 33 hem blade 34 air cylinder 35 Working hole 40 General-purpose jig 50 Clamp mechanism 51 props 52 Toggle mechanism 53 Open / close lever 54 Operation lever 55 Operation rod 60 Lower mold type display 62 Setting board 63 holes 64 protrusions 70 Lower model stand 80 Arm position detector 90 hem blade position detector

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Claims (3)

[Claims] 1. A system for positioning and holding a work in a lower mold which is positioned and held on a work stage at a fixed position and hemming a work peripheral portion with a robot arm. A general-purpose jig that positions and holds a selected lower mold of the lower mold on the upper surface, and is installed so that it can be moved to multiple positions on the upper surface of this general-purpose jig and can be opened and closed at the installation location. It has a plurality of clamp mechanisms that press the peripheral part of the work on the lower die to position and hold it on the lower die by closing operation.The general-purpose jig that holds the lower die in position is positioned and held on the work stage. A hemming system that features hemming of workpieces. 2. A guide projection for guiding a general-purpose jig on the work stage when the general-purpose jig is placed on the work stage, and an outer circumference of the general-purpose jig guided by the guide projection. 2. The hemming processing system according to claim 1, further comprising a guide roller which is brought into contact with and is driven to rotate to position and hold the general-purpose jig at the final position on the work stage. 3. A method of positioning and holding a work on a lower mold which is positioned and held on a work stage at a fixed position and hemming the periphery of the work with a robot arm, wherein a plurality of types of lower molds corresponding to a plurality of types of works are used. On the upper surface of a general-purpose jig that positions and holds the lower mold of any selected type, the position can be moved to multiple arbitrary positions on this upper surface.
In addition, it is installed so that it can be opened and closed at the installation location, and it is equipped with multiple clamping mechanisms that press the peripheral part of the work on the lower mold to position and hold it in the lower mold by closing operation Position and hold the jig on the work stage,
The robot arm closes the multiple clamp mechanisms in order and presses the peripheral part of the work on the lower die to position and hold it, while the robot arm controls the opening and closing of the multiple clamp mechanisms to hemm the peripheral edge of the work. A hemming method characterized by: