JP2000343156A - Hemming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To substantially reduce or eliminate an upper pressing force acting on a lower die so as to realize thinning of the lower die by adding an upward external force to the bottom face of the lower die at the hemming processing time in a hemming device of such a type that a processing unit for performing the hemming processing by pressurizing a work being arranged and held on the lower die is installed at a peripheral part of the lower die. SOLUTION: By this hemming device, hemming processing is performed to the outer periphery of a work W by a processing unit 10 installed to the peripheral part of a lower die 2, under a condition that the work W being put on the lower die 2 is pressed from above by a work presser 5. When a toggle mechanism 31 and a parallel link mechanism 12 are actuated by a hemming cylinder 41 and the work W is pressurized from above by a hem blade 20 so as to perform hemming processing, the lower die 2 is pressurized from below by a chucking arm 21 actuated via the toggle mechanism 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hemming apparatus for hemming an outer peripheral portion of a part such as an automobile door or hood.

[0002]

2. Description of the Related Art With respect to this type of hemming device, for example, a technology disclosed in Japanese Patent Application Laid-Open No. 7-232220 is known. In this technique, a press machine is used, and an upper die and a lower die are attached thereto, and a prehem blade and a hem blade are attached to the upper die. When a predetermined work is placed on the lower mold and positioned, and the upper mold is lowered by a press slide in this state, the work can be hemmed by the pre-hem blade and the hem blade.

[0003] Some hemming apparatuses do not use a press machine. As an example, a hemming apparatus using an articulated robot is known. In this apparatus, hemming is performed by controlling the movement of a workpiece placed on a lower mold while pressing and pressing a roller attached to the tip of a robot arm.

[0004]

The hemming apparatus using the above press machine requires large-scale equipment such as a press machine and a vertical type, so that the equipment cost is high.
In addition, the installation space becomes large. Further, even a hemming device using a robot requires an expensive high-load robot, and furthermore, it is necessary to secure an operation space for the robot arm in addition to the installation space for the device. Therefore,
The present applicant has proposed a new type of hemming device in view of the conventional problems as described above. This new type of hemming device includes a pre-bending process (hereinafter referred to as a pre-hemming process) for a work placed and held on the lower die at a peripheral portion of the lower die.
A processing unit capable of performing two processings, that is, a main bending processing (hereinafter, referred to as a hemming processing) subsequent thereto, is provided.

The above processing unit includes a parallel link mechanism with a hem blade and a toggle mechanism for amplifying the driving force of the actuator and transmitting the amplified force to the parallel link mechanism. Hemming is performed by applying pressure from above with a blade.
According to the hemming device having such a configuration, it is possible to reduce the equipment cost and the installation space as compared with the conventional hemming device. by the way,
The hemming process by the processing unit as described above is performed by pressing the work held by the lower die from above, and at this time, an extremely large pressing force acts on the lower die in each processing unit (for example, If the car door panel is hemmed, a pressing force of about 80 tons is applied.) For this reason, it is necessary to set the lower mold to be thick so as to withstand the pressing force (no bending is generated). As a result, the weight of the lower mold becomes large, and the weight of the whole apparatus also increases, and there is a problem that the handling is difficult when transporting to a factory or installing after manufacturing.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to press a work placed and held on the lower die from above into a peripheral portion of the lower die. In a hemming device of the type in which a processing unit for performing hemming is installed, the upper pressing force acting on the lower die is substantially reduced or eliminated by applying an upward external force to the lower surface of the lower die during hemming. The thickness of the lower mold is reduced.

[0007]

Means for Solving the Problems In order to achieve the above object, a hemming device according to the present invention has a configuration as described in each of the claims. Therefore, claim 1
According to the invention, the hemming device is constituted by the lower die, the work presser and the processing unit without the need for a press machine, so that the equipment cost is reduced, and the entire device is compact and the installation space is reduced. You. In particular, in the present invention, when the work placed on the lower die is pressed from above by a hem blade provided in the upper pressing mechanism to perform hemming, the lower die is supported from below by the lower pressing mechanism. In other words, since the pressing force acts in such a manner that the lower die is sandwiched from above and below, the upper pressing force acting on the lower die can be offset by the lower pressing force. For this reason, the force for bending the lower mold is greatly reduced or eliminated, and the thickness of the lower mold is reduced. As a result, the weight of the lower mold is reduced, so that the legs and the base for supporting the lower mold can be reduced in size and weight, and the weight of the entire hemming device can be reduced.

According to the second aspect of the present invention, the upper pressing mechanism with the hem blade can be switched between the pre-hemming position and the hemming position by the machining position switching mechanism. Processing can be performed by the same processing unit. For this reason,
As a result of halving the number of processing units compared to a type having dedicated processing units for pre-hemming and hemming, cost reduction of equipment costs and reduction of installation space are more remarkable.

According to the third aspect of the present invention, since the upper and lower pressing mechanisms of the processing unit are operated by a common actuator, there is no need to add additional actuators. Furthermore, according to the invention of claim 4, the drive force of the actuator is amplified and transmitted to the parallel link mechanism forming the upper pressing mechanism and the chucking arm forming the lower pressing mechanism by the toggle mechanism. be able to. Therefore, when the pressure required for hemming is constant, the actuator can be reduced in size, the processing unit can be made compact, and the entire apparatus can be made compact.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing the entire hemming device. As shown in the figure, a lower mold 2 supported by a plurality of (for example, four) legs (not shown) is fixed to an upper surface of a base 1 in the hemming device.
The lower die 2 is made of, for example, a casting, and is formed in a substantially rectangular frame shape whose center portion is open in plan view. Lower mold 2
The lifter 3 which is moved up and down by an air cylinder 4 installed vertically on the base 1
Is arranged. The lifter 3 can place the work W on its upper surface, and the work W is carried in / out by a work carry-in / out device (for example, a robot) (not shown) at a position elevated above the upper surface of the lower mold 2. The work W carried in from the work carry-in / out device is moved onto the lower mold 2 by lowering (lower position) than the upper surface of the lower mold 2. The upper surfaces of the lower die 2 and the lifter 3 are formed in a shape corresponding to the shape of the work W, but the lower surface of the lower die 2 is formed as a flat surface.

A work holder 5 for positioning and fixing a work W placed on the lower mold 2 prior to hemming is disposed above the lower mold 2. The work presser 5 is mounted on a frame (not shown) so as to be able to move up and down, or is mounted on the frame so as to be able to turn up and down via a swing arm. It is adapted to be moved between a raised position for releasing the holding down of W. A positioning pin 6 is provided on the lower surface of the work holder 5.

FIG. 2 is an enlarged sectional view showing the hemming operation of the work W by the hem blade 20 described later together with the lower die 2 and the work holder 5. Work W represented by doors and hoods for automobiles includes an inner panel W1 and an outer panel W2.
It consists of The hemming process by the hem blade 20 is a process of caulking the outer peripheral portion W2a of the outer panel W2 to the flange W1a of the inner panel W1. A pre-bending process to bend to an angle of approximately 45 degrees as shown in FIG. 2A and a further four bending as shown in FIG.
It is performed in two stages, namely, the main bending process of bending and crimping five times. In the following description, the preliminary bending is referred to as preheming, the main bending is referred to as hemming, and both of these are collectively referred to as hemming.

In the present embodiment, both the pre-hemming and the hemming are performed by the same hem blade 20. For this purpose, the tip of the hem blade 20 is moved to the position shown in FIG.
As shown in the figure, the pre-hem processing surface 2 inclined at approximately 45 degrees.
0a and a hemmed surface 20b formed substantially horizontally, and the two processed surfaces 20a and 20b are displaced vertically and horizontally as shown in the figure.

Processing units 10 for performing the above-mentioned hemming processing are arranged at necessary places in the peripheral part (front, rear, left and right) of the outer periphery of the lower mold 2, in the present embodiment, at the front part and the left and right three places. The above-described work loading / unloading device is disposed at the rear. Hereinafter, the configuration and the processing operation of the processing unit 10 will be described with reference to FIGS. Processing unit 10
Are roughly divided into a hydraulic hem cylinder 41 as an actuator for operating the hem blade 20, a parallel link mechanism 12 as an upper pressing mechanism with a hem blade for pressurizing the workpiece W from above and hemming, and a lower die for hemming. 2
Arm 21 as a lower pressurizing mechanism for supporting the lower part from below, a toggle mechanism 31 for amplifying the driving force of the hem cylinder 41 and transmitting the driving force to the parallel link mechanism 12 and the chucking arm 21, and the above members directly involved in hemming. A supporting unit bracket 11. In addition, in order to switch the processing position by the hem blade 20 between the pre-hem processing position and the hem processing position by moving the unit bracket 11 toward or away from the lower mold 2 during the pre-hem processing and the hem processing. The processing position switching mechanism 61 is provided.

The processing position switching mechanism 61 is mainly composed of a slide table 62 slidably mounted on the base 1 of the hemming device in a lateral direction. This slide table 62
The first for regulating the prehem processing position fixed on the base 1
Of the air cylinder 63 within a range regulated by the stopper 64 of the second embodiment and the second stopper 65 for regulating the hemming position.
, It is possible to switch between a pre-hem processing position approaching the lower mold 2 (see FIGS. 4 and 5) and a hemm processing position moving away from the lower mold 2 (see FIGS. 7 and 8).
Then, the unit bracket 1 is placed on the slide base 62.
1 is erected and fixed. Note that a stopper portion 62a that can abut against the stoppers 64 and 65 is set on an end surface of the slide table 62 in the moving direction.

The unit bracket 11 is composed of two front and rear vertical plates which are arranged opposite to each other at a predetermined interval in a direction perpendicular to the plane of FIG. 3. A parallel link mechanism 12 is mounted on the upper side of the unit bracket 11. A pair of upper and lower parallel links 13 and 14 are rotatably mounted on shafts 15 and 16. A blade holder 17 is rotatably attached to the tips (lower mold side) of the parallel links 13 and 14 by shafts 18 and 19, and the hem blade 20 having the above-described structure is attached to the blade holder 17 downward. I have.

A chucking arm 2 for supporting the lower surface of the lower mold 2 is provided below the unit bracket 11.
1 is rotatably supported by a shaft 22 at a substantially middle portion in the longitudinal direction. One end of the chucking arm 21 is extended toward the lower surface of the lower mold 2, and a pressure plate 23 is fixed to the end of the chucking arm 21 so as to be in contact with the lower mold 2 with a slight gap therebetween. .

On the other hand, the toggle mechanism 31 is a pair of upper and lower toggles which are vertically arranged in a V-shape between the vertical plates constituting the unit bracket 11 and are connected to each other by a connecting shaft 32 so as to be freely rotatable. It is constituted by links 33 and 34. And both toggle links 33, 34
The upper end of the upper toggle link 33 is connected to the extension end of the upper link 13 in the parallel link mechanism 12 by the shaft 3.
5 and a lower toggle link 3
4 is connected to the other end of the chucking arm 21 by a shaft 3
6 are rotatably connected. The parallel links 13 and 14, the chucking arm 21, and the toggle links 33 and 34 are provided between the vertical plates constituting the unit bracket 11, each of two front and rear pairs.

Further, the hem cylinder 41 is rotatably driven by a horizontal shaft 42 in a state where the hem cylinder 41 is horizontally disposed between the two vertical plates constituting the unit bracket 11 so that a part of the hem cylinder 41 enters the lower space of the lower mold 2. Supported. And the piston rod of the hem cylinder 41 is a knuckle 4
3 is connected to the connection shaft 32 of both links 33 and 34 of the toggle mechanism 31. Therefore, the driving force (thrust) at the time of the expansion / contraction operation of the hem cylinder 41 is transmitted from the connection shaft 32 of the toggle mechanism 31 to the parallel link mechanism 12 via the upper toggle link 33, and the chucking arm via the lower toggle link 34. 21. This allows the hem blade 20 to move from the standby position shown in FIGS.
8 and the chucking arm 21 presses the lower surface of the lower mold 2 upward (see FIGS. 5 and 8) or releases the pressurization (see FIGS. 4 and 8). 7).

Also, two stoppers 51, 5 for regulating the lower end (working end position) of the hem blade 20 at the time of hemming and for regulating the prehem lowering position and the hem lowering position.
3 are provided. The stopper 51 for regulating the prehem lowering position is a block-shaped stopper for restricting the movement of the toggle mechanism 31 by contacting a stopper plate 34a provided at the tip of the lower toggle link 34. The stopper 51 is provided with a substantially U-shaped guide 52 provided on the side surface of the slide table 62.
The stopper plate 34a is configured to be horizontally slidable back and forth between a position on the movement trajectory line of the stopper plate 34a and a position off the movement trajectory line by an air cylinder (not shown). On the other hand, the stopper 53 for regulating the hem lowering position is constituted by a concave portion 54 provided on the upper toggle link 33 and a projection 55 provided on the lower toggle link 34 on the connecting shaft 32 side. The projection 55 is engaged with the
Restrict the movement of 1.

Next, the hemming process performed by the hemming device configured as described above will be described. In FIG. 1, when the lifter 3 is raised to a position higher than the upper surface of the lower die 2, a work W to be processed is carried in by a work carrying-in / out device (not shown). After the work W is carried in, when the lifter 3 is lowered to a position lower than the upper surface of the lower mold 2, the work W is transferred from the upper surface of the lifter 3 to the upper surface of the lower mold 2. Next, the work holder 5 descends so as to press the work W, and the positioning pin 6 is moved to the inner panel W1.
, And hold this state until the hemming process is completed. In this case, when carrying the work W onto the lower mold 2, each processing unit 10 stands by with the position shown in FIG. 3 as an original position so that the work W does not interfere with the hem blade 20.

Subsequently, hemming is performed by the three processing units 10 installed around the lower mold 2 in synchronization. First, the stopper portion 62a of the slide base 62 is laterally moved (close to the lower die 2) to a position where it comes into contact with the first stopper 64 by the air cylinder 63 for switching the processing position, and the processing position of the hem blade 20 becomes the pre-hem processing position. (See FIG. 4).

When the hem cylinder 41 is extended in this state, as shown in FIG. 5, the connecting shaft 32 of the toggle mechanism 31 is pushed, and the toggle links 33 and 34 are connected.
And elongate while pivoting around. This allows
The hem blade 20 is lowered toward the lower mold 2 via the parallel link mechanism 12, and the outer peripheral portion W2a of the outer panel W2 is bent by the prehem processing surface 20a into a state shown in FIG. In synchronization with the pre-hem processing, the pressure arm 21 rotates about the shaft 22 as a fulcrum, and presses the lower surface of the lower die 2 upward by the pressing plate 23. That is, prehem processing is performed by the hem blade 20 while the lower mold 2 is supported from below by the chucking arm 21. Then, when the pre-hem processing is completed, the stopper plate 34a of the lower toggle link 34 comes into contact with the stopper 51 for regulating the pre-hem lowering position, and stops the hem blade 20 at the specified lower end position. FIG. 6 schematically shows the above-mentioned prehem machining operation. After pre-hem processing,
By the contraction operation of the hem cylinder 41, the hem blade 20 and the pressure plate 23 return to the original standby position (the position shown in FIG. 4).

Next, an air cylinder 63 for switching the processing position
As a result, the stopper portion 62a of the slide base 62 is laterally moved (separated from the lower mold 2) to a position where it comes into contact with the second stopper 65, and the processing position of the hem blade 20 is switched to the hem processing position (see FIG. 7). Further, the stopper 51 for regulating the prehem lowering position is moved along the guide 52 by the air cylinder for switching the stopper position, and is retracted from the rotation trajectory line of the lower toggle link 34.

When the hem cylinder 41 extends in this state, as shown in FIG. 8, the parallel link mechanism 12 and the chucking arm 12 are respectively operated via the toggle mechanism 31 in the same manner as in the above-described pre-hem processing. That is, the outer peripheral portion W2a of the outer panel W2 is bent as shown in FIG. 2B by the hem processing surface 20b of the hem blade 20, and the lower surface of the lower mold 2 is pressed upward by the pressing plate 23 at the same time. When the hemming is completed, the protrusion 55 of the lower toggle link 34 comes into contact with the concave portion 54 of the upper toggle link 33, and the hem blade 20 is stopped at the prescribed lower end position. FIG. 9 schematically shows the hemming operation. After the hem machining, the hem cylinder 41 is contracted, the hem blade 20 and the pressure plate 23 are returned to the original standby position (the position shown in FIG. 7), and the pre-hem stopper is operated by the operation of the air cylinder for switching the stopper position. The reference numeral 51 is returned to the original position shown in FIG. 3 by returning to the rotation locus line of the lower toggle link 34, and prepares for the next hemming process.

Thus, when a series of hemming processes by the pressure unit 10 is completed, the work holder 5 is moved upward to release the work W from being held down. Next, when the lifter 3 rises and pushes up the work W on the lower die 2, the work W is carried out by a work carrying-in / out device (not shown) at the raised position.

As described above, according to the present embodiment, a plurality of processing units 10 are installed around the lower die 2 and hemming is performed on the work W set on the lower die 2 from the lateral direction. , The equipment cost is reduced as compared with a hemming device using a press machine or a robot, and the entire device becomes compact. In particular,
In the hemming device according to the present embodiment, at the time of preheming and hemming, hemming is performed by the hem blade 20 while the lower mold 2 is supported from below by the chucking arm 21. Can be offset by the lower pressing force. For this reason, even if the lower mold 2 is formed thin (in the vertical direction) and is supported by about four supporting legs, the lower mold 2 can be prevented from being bent by the upper pressing force, and a predetermined processing accuracy can be secured. . Therefore, it is possible to make the lower mold 2 thinner and lighter. As a result, it is possible to adopt a structure in which the lower mold 2 is supported by about four legs, and to reduce the size of the base 1 that supports the lower mold 2. Lightening is also possible. For this reason, the weight of the entire device is reduced, and the handling of the hemming device for transportation and installation can be improved. Also, miniaturization of the lower mold 2
In order to reduce the size of the mold required for manufacturing the lower mold 2,
As a result, mold costs, material costs, and the like are reduced, and manufacturing costs can be reduced.

Further, by connecting the parallel link mechanism 12 to one end of the toggle mechanism 31 and the chucking arm 21 to the other end, the hemming operation by the hem blade 20 and the pressing of the lower die 2 from below. Operation and toggle mechanism 31
Can be performed by a single hem cylinder 41 that drives the motor. Therefore, the number of driving devices is small, and the driving force can be amplified by the toggle mechanism, so that the hem cylinder 41 can be made compact (small diameter). In addition, since the hem cylinder 41 is arranged by utilizing the space below the lower mold 2, the entire processing unit 10 can be moved toward the lower mold 2, and the entire apparatus can be made compact.

It should be noted that the present invention is not limited to the illustrated embodiment, and may be appropriately changed without departing from the gist of the present invention. For example, the hem cylinder 41
Can be changed, or the embodiment in which the toggle mechanism 31 is omitted can be used. Further, the hem cylinder 41, the air cylinder 63 for switching the processing position, and the like may be changed to an electric cylinder. Further, an upper pressing mechanism with a hem blade that presses the workpiece W from above with the hem blade 20 to perform hemming, and a lower pressing mechanism that presses the lower surface of the lower mold 2 upward during hemming are controlled by individual actuators. It is possible to adopt a driving type or to apply to a hemming device of a type in which preheming and hemming are performed by individual dedicated machining units. Naturally, the work W is not limited to the door of the car.

[0030]

As described in detail above, according to the present invention,
In a hemming apparatus of a type in which a processing unit for performing hemming by pressing a work placed and held on the lower die from above is installed around the lower die, the lower die is turned upward during hemming. By preventing the lower mold from being bent by the upper pressing force applied to the lower mold, it is possible to reduce the thickness and weight of the lower mold, and further reduce the weight of the entire apparatus.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the entire hemming device.

FIGS. 2A and 2B are enlarged cross-sectional views illustrating a hemming process using a hem blade. FIG. 2A shows pre-hemming, and FIG. 2B shows hemming.

FIG. 3 is a side view showing a processing unit.

FIG. 4 is a side view showing a prehem standby state of the processing unit.

FIG. 5 is a side view showing a pre-hem processing state of the processing unit.

FIG. 6 is a schematic diagram of a pre-hem processing operation.

FIG. 7 is a side view showing a hem standby state of the processing unit.

FIG. 8 is a side view showing a hemming state of the processing unit.

FIG. 9 is a schematic view of a hemming operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Lower mold 5 ... Work holder 10 ... Work unit 11 ... Unit bracket 12 ... Parallel link mechanism 20 ... Hem blade 21 ... Chucking arm 31 ... Toggle mechanism 41 ... Hem cylinder 61 ... Processing position switching mechanism 62 ... Slide table

Claims (4)

[Claims] 1. A hemming device for setting a work including an inner panel and an outer panel in a positioned state, and performing hemming processing so as to crimp an outer peripheral portion of the outer panel to a flange of the inner panel. A lower die to be placed, a work presser that presses and positions a work on the lower die, and a processing unit that is installed in a peripheral portion of the lower die and performs the hemming processing. An upper press mechanism with a hem blade that presses the work from above with a hem blade to perform hemming, and a lower press mechanism that presses the lower surface of the lower mold upward simultaneously with pressurization of the work by the hem blade. Hemming device. 2. The hemming device according to claim 1, wherein
The hemming device includes a processing unit that includes a processing position switching mechanism that switches an upper pressing mechanism with a hem blade to a prehem processing position and a hemm processing position. 3. The hemming device according to claim 1, wherein
A hemming device in which an upper pressing mechanism and a lower pressing mechanism of a processing unit are operated by a common actuator. 4. The hemming device according to claim 3, wherein
The upper pressing mechanism is constituted by a parallel link mechanism, the lower pressing mechanism is constituted by a chucking arm, and one end of a toggle mechanism operated by an actuator is connected to the parallel link mechanism, and the other end is connected to the chucking arm. Hemming equipment.