Two-degree-of-freedom metal plate bending follow-up supporting device and kinematics inverse solution method thereof
Technical Field
The invention relates to a material supporting device in the field of plate bending, in particular to a two-degree-of-freedom metal plate bending follow-up material supporting device and a kinematics inverse solution method thereof.
Background
Numerical control plate bending is an important technological method in the manufacturing industry and has high proportion. When large-size plate bending is carried out, the processing difficulty is high, and the following problems exist: 1. the self gravity sag of the plate can have adverse effect on the processing precision; 2. the turnover speed is high, when the weight of the plate is large, a plurality of people are required to bend the plate to perform auxiliary operation, and the labor intensity is high; 3. potential safety hazards exist.
The material supporting device disclosed in the prior art on the current market has the following defects: 1. the structure is too complex, the occupied area is large, and the volume is heavy; 2. the response speed is low, and the requirement of high-speed bending processing cannot be met; 3. the kinematic inverse solution of the mechanism cannot be realized, the deviation of the follow-up track is large, and the follow-up effect is poor; 4. the following turnover angle is small.
In addition, in the metal plate bending industry, in recent years, auxiliary bending is performed by using a robot, and although the automation degree is high, the following problems still exist: 1. the structure is complex, and the cost is high; 2. the teaching programming is needed, the processing of a large batch of single-variety parts is satisfactory, but the teaching programming is not applicable to a small batch and multi-variety processing mode, and the teaching programming efficiency is too low; 3. only for applications with a low weight.
Therefore, it is desired to solve the above problems.
Disclosure of Invention
The purpose of the invention is as follows: the first purpose of the invention is to provide a two-degree-of-freedom metal plate bending follow-up supporting device which can realize inverse kinematics, is accurate in follow-up track, good in follow-up effect, high in response speed and large in turnover angle.
The second purpose of the invention is to provide a kinematic inverse solution method of the two-degree-of-freedom metal plate bending follow-up supporting device.
The technical scheme is as follows: in order to achieve the purpose, the invention discloses a two-degree-of-freedom metal plate bending follow-up supporting device which comprises a fixed base, a fixed rail obliquely arranged on the fixed base, a lifting frame capable of moving back and forth along the fixed rail and a turning bedplate hinged with one end of the lifting frame and used for supporting plates.
Wherein, the turnover bedplate is horizontally arranged under the non-working state.
Preferably, the inclination angle between the fixed rail and the fixed base is γ, and the lifting frame moves back and forth along the fixed rail to form a moving pair, and the slope of the moving pair is tan (γ).
Further, the lifting frame is driven by a roller screw rod mechanism, a gear rack mechanism or a linear motor to move back and forth along the fixed track.
Moreover, the turnover bedplate is articulated with the crane to form a revolute pair, and the revolute pair is driven to rotate by the rotating shaft.
The invention discloses a kinematics inverse solution method of a two-degree-of-freedom metal plate bending follow-up material supporting device, which comprises the following steps of:
(1) the lifting frame moves back and forth along the fixed track to form a moving pair, and the turning bedplate is hinged with the lifting frame to form a rotating pair; in a non-working state, the turnover table plate is in a horizontal arrangement state, in a working state, an upper die of the bending machine moves downwards, the plate is completely bent and deformed, the movement of the sliding pair and the rotating pair is driven in a coordinated manner, and the turnover table plate supports the plate to move along with the plate;
(2) firstly, establishing a coordinate system XOY, wherein an original point O is an intersection point of the upper surface of the overturning bedplate and the central position of a bending machine die in a non-working state; the vertical downward direction is the positive direction of the Y axis; the direction which is horizontal and points to the follow-up material supporting device is an X axis;
the point A is the intersection point of the upper surface of the overturning bedplate and the center position of the bending machine die in the working state, the point D is the hinge point of the overturning bedplate and the lifting frame in the working state, the point D is used as a parallel line of the upper surface of the overturning bedplate, and the intersection point of the parallel line and the center line of the bending die is the point B; the point C is a perpendicular point passing through the point A and serving as a perpendicular line AC of the straight line BD, and the point E is a perpendicular point passing through the point D and serving as a perpendicular line DE of the upper surface of the overturning platform board; the point F is a hinged point of the turnover table plate and the lifting frame under the non-working state, and the inclination angle of the fixed track and the fixed base is gamma;
(3) in the bending process, the bending half angle of the plate is alpha, the descending distance of the plate at the center position of a bending machine die is d, and the coordinate of the F point is (X)F,YF) The slope of the sliding pair is tan (gamma), and the feeding amount beta of the rotating pair and the feeding amount Dis of the sliding pair are solved according to the coordinate of the point F and the slope of the sliding pair; the concrete solving method comprises the following steps:
and if the included angle between the straight line DE and the vertical direction is beta, the feeding amount beta of the rotating pair is as follows:
the coordinates of the point B are as follows:
XB=0
wherein L is the distance from the rotating center of the rotating pair to the upper surface of the overturning plate,
the linear equation of connecting two points of DB into a straight line is as follows:
order:
the equation of the straight line to obtain the straight line DB is:
Y=a1X+b1
the equation of a straight line connecting two points DF into a straight line is as follows:
Y=tan(γ)X+(YF-tan(γ)XF)
order:
a2=tan(γ)
b2=YF-tan(γ)XF
then the equation of the straight line DF is obtained:
Y=a2X+b2
and solving the coordinate of the intersection point D of the two straight lines according to the straight line equation of DB and the straight line equation of DF:
and solving the distance of DF as the feed quantity Dis of the moving pair:
has the advantages that: compared with the prior art, the invention has the following remarkable advantages: firstly, in a working state, the two-degree-of-freedom metal plate bending follow-up material supporting device moves downwards along with an upper die of a bending machine, the plate is completely bent and deformed, a moving pair and a rotating pair are driven to move in a coordinated manner, and a turnover table plate supports the plate to move along with the plate; the turnover table plate supports the plate, and the plate is completely contacted and superposed with the surface of the turnover table plate, but can slide relatively; the labor intensity of workers is effectively reduced, and the processing precision, the processing efficiency and the processing safety are improved; secondly, the two-degree-of-freedom metal plate bending follow-up supporting device is low in cost, simple in structure and convenient to popularize; moreover, the two-degree-of-freedom metal plate bending follow-up material supporting device is high in response speed, the inverse kinematics solution method can realize inverse kinematics solution, so that the material supporting device is accurate in follow-up track and good in follow-up effect, and is suitable for follow-up setting in the heavy-load bending process; finally, compared with the prior art, under the same condition, the fixed rail and the fixed base are obliquely arranged, so that the invention can realize a larger follow-up turning angle and has strong turning capability.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic diagram of the mechanism movement of the present invention;
FIG. 3 is a schematic structural view of the present invention in use with a bending machine in a non-operational state;
FIG. 4 is a schematic structural view of the present invention in use with a bending machine in an operational state;
FIG. 5 is a schematic representation of the inverse kinematics of the present invention;
FIG. 6 is a first schematic diagram of the feeding amount and the turning angle of the fixed rail and the fixed base according to the present invention;
FIG. 7 is a second schematic view of the feeding amount and the turning angle of the fixed rail and the fixed base according to the present invention.
Detailed Description
The technical scheme of the invention is further explained by combining the attached drawings.
As shown in fig. 1 and 2, the two-degree-of-freedom metal plate bending follow-up supporting device comprises a fixed base 1, a fixed rail 2, a lifting frame 3 and a turnover table board 4. The fixed rail 2 is obliquely arranged on the fixed base 1, and the inclination angle between the fixed rail 2 and the fixed base 1 is gamma. The lifting frame 3 can move back and forth along the fixed track 2, and the lifting frame 3 moves back and forth along the fixed track to form a moving pair 5, and the slope of the moving pair is tan (gamma). The overturning platform plate 4 is hinged with one end of the lifting frame 3, and the overturning platform plate 4 is used for supporting plates. The lifting frame 3 is driven by a roller screw rod mechanism, a gear rack mechanism or a linear motor to move back and forth along the fixed track 2. The overturning bedplate 4 is hinged with the lifting frame 3 to form a revolute pair 6 which is driven to rotate by a rotating shaft.
As shown in fig. 3 and 4, an upper die 8 and a lower die 9 are arranged on a bending machine 7, the turnover table plate 4 is horizontally arranged in a non-working state, and in a working state, the plate 10 is completely bent and deformed along with the downward movement of the upper die of the bending machine, the movement of the sliding pair and the rotation pair is coordinately driven, and the turnover table plate supports the plate to move along with the plate; the turnover table plate supports the plate, and the plate is completely contacted and superposed with the surface of the turnover table plate, but can slide relatively.
The invention effectively reduces the labor intensity of workers and improves the processing precision, the processing efficiency and the processing safety; secondly, the two-degree-of-freedom metal plate bending follow-up supporting device is low in cost, simple in structure and convenient to popularize; the two-degree-of-freedom metal plate bending follow-up material supporting device is high in response speed, capable of realizing inverse kinematics, accurate in follow-up track, good in follow-up effect and suitable for follow-up setting in the heavy-load bending process.
As shown in FIG. 5, the kinematics inverse solution method of the two-degree-of-freedom metal plate bending follow-up material supporting device comprises the following steps:
(1) the lifting frame moves back and forth along the fixed track to form a moving pair, and the turning bedplate is hinged with the lifting frame to form a rotating pair; in a non-working state, the turnover table plate is in a horizontal arrangement state, in a working state, an upper die of the bending machine moves downwards, the plate is completely bent and deformed, the movement of the sliding pair and the rotating pair is driven in a coordinated manner, and the turnover table plate supports the plate to move along with the plate;
(2) firstly, establishing a coordinate system XOY, wherein an original point O is an intersection point of the upper surface of the overturning bedplate and the central position of a bending machine die in a non-working state; the vertical downward direction is the positive direction of the Y axis; the direction which is horizontal and points to the follow-up material supporting device is an X axis;
the point A is the intersection point of the upper surface of the overturning bedplate and the center position of the bending machine die in the working state, the point D is the hinge point of the overturning bedplate and the lifting frame in the working state, the point D is used as a parallel line of the upper surface of the overturning bedplate, and the intersection point of the parallel line and the center line of the bending die is the point B; the point C is a perpendicular point passing through the point A and serving as a perpendicular line AC of the straight line BD, and the point E is a perpendicular point passing through the point D and serving as a perpendicular line DE of the upper surface of the overturning platform board; the point F is a hinged point of the turnover table plate and the lifting frame under the non-working state, and the inclination angle of the fixed track and the fixed base is gamma;
(3) in the bending process, the bending half angle of the plate is alpha, the descending distance of the plate at the center position of a bending machine die is d, and the coordinate of the F point is (X)F,YF) The slope of the sliding pair is tan (gamma), and the feeding amount beta of the rotating pair and the feeding amount Dis of the sliding pair are solved according to the coordinate of the point F and the slope of the sliding pair; the concrete solving method comprises the following steps:
and if the included angle between the straight line DE and the vertical direction is beta, the feeding amount beta of the rotating pair is as follows:
the coordinates of the point B are as follows:
XB=0
wherein L is the distance from the rotating center of the rotating pair to the upper surface of the overturning plate,
the linear equation of connecting two points of DB into a straight line is as follows:
order:
the equation of the straight line to obtain the straight line DB is:
Y=a1X+b1
the equation of a straight line connecting two points DF into a straight line is as follows:
Y=tan(γ)X+(YF-tan(γ)XF)
order:
a2=tan(γ)
b2=YF-tan(γ)XF
then the equation of the straight line DF is obtained:
Y=a2X+b2
and solving the coordinate of the intersection point D of the two straight lines according to the straight line equation of DB and the straight line equation of DF:
and solving the distance of DF as the feed quantity Dis of the moving pair:
compared with the prior art, under the same condition, the fixed rail and the fixed base are obliquely arranged, so that the invention can realize larger follow-up turning angle and has strong turning capability.
As shown in fig. 6, when the same angle Rot0 is reversed, the feeding amount of the sliding pair in the non-tilt state is Dis1, and the feeding amount of the sliding pair in the tilt state is Dis 0. As shown in fig. 7, when the feeding amount is Dis1, the turning angle in the non-inclined state is Rot0, and the turning angle in the inclined state is Rot1, which is obviously larger when the fixed track and the fixed base are inclined.