JP2001001081A - Excitation device for hemming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the operation according to the nature of a work by converting the rotational motion of a rotary driving means into the advancing/ retracing motion in the linear direction to oscillate a hemming blade and freely set the frequency high. SOLUTION: A rotary driving means includes a mechanism with an eccentric weight fitted to a rotary shaft, and also includes a mechanism to oscillate a hemming blade by the component obtained thereby, or to circulate an output shaft on the circumference of a specified diameter, and the hemming blade is preferably oscillated by the reciprocating displacement obtained by this circulation. An electric motor or a compressed air driven rotating device may be adopted for the rotary driving means 15. The electric motors 16, 16 are coupled in the symmetrical manner in the right-to-left direction on both sides of a substrate 5, the eccentric weight is fixed to the rotary shafts 17, 17, a storage box is arranged adjacent to the electric motor 16, the eccentric weight is placed therein and located immediately above guide rods 10, 10 to reduce the bending load applied to bearings 7, 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Hemming is performed on steel plates and the like by vibrating a hem blade. In the hemming process, various improvements are required for the vibration generator for that,
The present invention belongs to such a technical field.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 10-249455 is an example of a prior art relating to the present invention. The vibration generating device disclosed here is connected to the tip of a robot device, and the reciprocating output of an air cylinder is used as a vibration generating source. Then, the vibration of the vibration generator is transmitted to the robot apparatus, that is, the arm system having a large number of joint structures (generally, six axes are generally used), and in order to avoid resonance between the vibration frequency and the natural frequency of the arm system. In addition, an adjustment weight is attached, and a cushioning material is interposed in the amplitude direction of the air cylinder.

[0003]

The above-described techniques have the following problems. If the vibration source is an air cylinder, it is difficult to freely select the frequency according to the characteristics of the work. This applies air pressure alternately to both sides of the piston of the air cylinder, which limits the vibration control due to the flow resistance during air supply / discharge and the compressibility of the air itself. This is a problem particularly when the frequency is increased.

Further, if an adjustment weight is installed to avoid the above-mentioned resonance, the mass of the vibration generator becomes large,
The load on the robot apparatus becomes excessively large, and therefore, it is necessary to sufficiently strengthen the arm system. When an air cylinder is employed, there is a limit to increasing the frequency of vibration in order to increase the kinetic energy of the hem blade or a member integral therewith, so there is no other way but to increase the mass of the vibrating member. At this point, the mass must be excessive. Under such circumstances, if the mass of the exciter increases,
Since a bending phenomenon occurs in the arm system of the robot, it is necessary to set a behavior trajectory in anticipation of this bending amount during teaching. Such teaching adjustment needs to be repeated many times, and it takes a long time for the initial setting.

[0005]

SUMMARY OF THE INVENTION The present invention has been provided to solve the above-mentioned problems.
According to a first aspect of the present invention, in a type in which hemming processing is performed on a steel plate or the like by applying vibration to the hem blade, the hem blade is vibrated by converting the rotational movement of the rotary drive means into a linear forward / backward movement. It is characterized by having comprised. Therefore, by selecting the number of rotations, a high frequency can be set freely, and an operation according to the properties of the work can be performed.

According to a second aspect of the present invention, in the first aspect, the rotation driving means includes a mechanism in which an eccentric weight is attached to the rotating shaft, and the hem blade is vibrated by a component force obtained by the eccentric weight. It is characterized by having been constituted. Therefore, the hem blade is vibrated by the reciprocating component synthesized by the rotation of the eccentric weight.

According to a third aspect of the present invention, in the first aspect, the rotary drive means includes a mechanism for rotating the output shaft on a circle having a predetermined diameter. Is configured to vibrate. Therefore, the amplitude is determined by the above diameter, but the frequency can be freely selected by selecting the number of rotations of the rotation driving means.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. First, referring to FIGS. 1 to 3, reference numeral 1 denotes an arm of a six-axis robot device, and a hemming unit 2 is coupled to the tip of the arm. An elastic body 3 is coupled to the arm 1 and a substrate 5 is fixed to a support plate 4 integral with the elastic body 3 in the vertical direction. A bearing support plate 6 is connected to the lower part of the substrate 5 in the horizontal direction.
The bearings 7, 7 are firmly fixed to the bearing support plate 6 while penetrating the support plate 6.

The hem blade 8 is fixed to a support rod 9, and a guide rod 10 is fixed to the support rod 9, and the rods 10, 10 pass through the bearings 7, 7. Flanges 11 and 12 are respectively connected to the upper and lower sides of the guide rods 10 and 10. A buffer spring 13 is provided between the flange 11 and the bearing support plate 6.
A buffer spring 14 is disposed between the bearing and the bearing support plate 6. The bearings 7, 7 have a cylindrical shape and are not shown, but are actually supported by bowl-type bearings in which a large number of steel balls are arranged to reduce frictional resistance and have a structure resistant to bending moment. Have been. Further, the buffer springs 13 and 14 may be coil springs as shown, or may be urethane rubber. The elastic body 3 may be a coil spring or urethane rubber as shown. These elastic members 3 and coil springs 13 and 14
Is to reduce the transmission of the impact reaction force of the hem blade 8 to the arm 1.

Various means such as an electric motor and a rotary device driven by compressed air can be used as the rotation drive means 15. Here, an electric motor type is used. Electric motors 16, 16 are symmetrically coupled to both sides of the substrate 5, and eccentric weights 18, 18 are attached to their rotating shafts 17, 17.
Has been fixed. As is apparent from FIG. 1, storage boxes 18a, 18a are arranged adjacent to the electric motor 16, and the eccentric weights 18, 18 are contained therein. As can be understood from FIGS. 1 and 2, the eccentric weight 18 is located right above the guide rods 10, 10, thereby reducing the bending load acting on the bearings 7, 7.

One of the rotating shafts 17, 17 is clockwise,
The other rotates counterclockwise, and the eccentric weight 1
As shown in FIG. 3, the reference numerals 8 and 18 have an opposite phase relationship. Therefore, the components in the vertical direction of the two eccentric weights are extracted as a “sum”, but the components in the other directions are canceled. Due to such a vibration phenomenon, the vibration in the vertical direction is transferred from the substrate 5 to the bearing support plate 6 and the buffer spring 1.
It is transmitted to the hem blade 8 via the flanges 3 and 14 and the flanges 11 and 12. Reference numeral 19 denotes a peripheral portion of a door of an automobile, and an outer plate 21 is bent with respect to an inner plate 20. Although the hem blades 8 are of a tandem type as shown in FIG. 2, it is needless to say that the hem blades 8 may be of a single type.

According to this embodiment, the eccentric weight 1
Since the combined vibrations of 8, 18 are used, the vibration frequency can be freely and freely selected by setting the rotation speed of the electric motors 16, 16, and a high vibration frequency can be easily selected.
Further, although not shown here, both eccentric weights 1
It is also possible to change the amplitude by shifting the phases of 8 and 18. As a result, a hem blade vibration adapted to the state of the hemming portion, for example, the extension flange, the contraction flange, the bending rigidity, and the like can be obtained.

With the above characteristics, the resonance frequency with the arm system can be completely prevented by increasing the frequency, and the adjustment weight described above can be omitted. Therefore, the mass of the hemming unit 2 can be reduced, and it is possible to prevent the arm system from being strengthened or troublesome during teaching.

In the above embodiment, two electric motors are mounted. However, the electric motors may be replaced with one electric motor. In order to do this, the rotation of the electric motor is transmitted to two gears, and an eccentric weight may be attached to the shaft of this gear.

Another embodiment of FIGS. 4 and 5 will be described. Components that perform the same functions as the members in the previous embodiment are denoted by the same reference numerals in the drawings, and detailed description is omitted. An electric motor 16 is fixed to the lower surface of the support plate 4, and a gear converter 22 is connected to an end of the electric motor 16. The output shaft 23 of the gear converter 22 circulates on the circumference 24 shown in FIG. 5, and the diameter of the circumference 24 is set according to the required amplitude. Universal joint 25 on output shaft 23
Is attached thereto, and an air damper 26 is connected to the air damper 26. The damper 26 is connected to the guide rod 10 via a ball joint 27. The air damper 26 has a telescopic structure. The member indicated by the two-dot chain line in FIG. 4 is a reinforcing triangular plate for increasing the coupling rigidity between the support plate 4 and the substrate 5.

The rotation of the electric motor 16 causes the output shaft 23 to rotate.
Makes a circumferential motion, the displacement is transmitted to the hem blade 8 via the air damper 26, the ball joint 27, and the guide rod 10, and hem blade vibration is obtained. The air damper 26 oscillates.
Is arranged.

Also in this embodiment, the frequency of the hem blade 8 can be freely selected by selecting the number of revolutions of the electric motor 16, and the same operation and effect as in the previous embodiment can be obtained.

[0018]

According to the present invention, not the air cylinder as in the prior art, but the motion of the rotary driving means typified by the electric motor is converted into the linear reciprocating motion to vibrate the hem blade. Therefore, the frequency can be freely selected, and resonance with the arm system of the robot can be avoided. Therefore, the adjustment weight can be omitted, the weight of the hemming unit can be reduced, and the reinforcement of the arm system can be minimized or stopped, which is effective in reducing equipment costs.

Further, since the kinetic energy of the hem blade can be improved by increasing the speed of the hem blade, the amplitude of the vibration transmitted to the arm system is reduced. Vibrational effects on the system can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a front view of that of FIG.

FIG. 3 is a front view showing a portion of an eccentric weight.

FIG. 4 is a side view showing another embodiment.

FIG. 5 is a partial front view showing a position of an output shaft.

[Explanation of symbols]

 8 Hem blade 15 Rotation driving means 17, 17 Rotary shaft 18, 18 Eccentric weight 23 Output shaft

Claims (3)

[Claims] An apparatus for performing hemming of a steel plate or the like by imparting vibration to a hem blade, wherein the hem blade is vibrated by converting the rotational movement of the rotary drive means into a linear forward / backward movement. An exciter for hemming, comprising: 2. The rotation driving means according to claim 1, wherein the rotation driving means includes a mechanism having an eccentric weight attached to a rotation shaft,
A vibrating device for hemming, wherein the hem blade is vibrated by a component force obtained by the eccentric weight. 3. The rotation driving means according to claim 1, wherein the rotation driving means includes a mechanism for rotating the output shaft on a circle having a predetermined diameter, so that the hem blade is vibrated by a reciprocal displacement obtained by the rotation. A vibrating device for hemming, comprising: