Four-rod pushing mechanism for cigarette packaging machine

Abstract

The invention discloses a four-rod pushing mechanism for a cigarette packaging machine. The four-rod pushing mechanism comprises a crank, a connecting rod, a frame connecting rod and a rack. According to the four-rod pushing mechanism, given points on the connecting rod plane can move according to a D-shaped track. The linear part of the D-shaped track is used for completing work such as material pushing, the curve part of the D-shaped track is used for avoiding materials, and frequent pause caused by cigarette avoiding in the cigarette packaging process is avoided.

Description

Technical Field

[0001] The invention relates to the field of packaging machinery, and in particular to a four-rod material pushing mechanism used in a cigarette packaging machine. Background Art

[0002] In the production of cigarettes, a very important process is to pack the cigarette packs with film. During the film packing process, the cigarette packs need to be pushed into the film packing machine one by one. Figure 1 The figure shows the working diagram of the pusher mechanism in the cigarette packaging machine. In the pusher mechanism, the pusher head 5 is required to deliver the cigarette pack 6 to the packaging station. In this process, the motion trajectory of the pusher head 5 is generally a straight line. When the pusher head 5 returns, it needs to avoid the cigarette pack, so its motion trajectory is a curve. There is no special requirement, and it is generally a semicircular arc. It can be seen that in order to complete the pusher task, the pusher head 5 needs to move according to a specific trajectory similar to the "D" shape. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a four-rod pusher mechanism capable of realizing a specified motion trajectory. In order to solve the above technical problem, the technical solution provided by the present invention is as follows:

[0004] A four-bar pusher mechanism for a cigarette packaging machine includes a crank, a connecting rod, a connecting rod and a frame. The length of the crank is a, the length of the connecting rod is b, the length of the connecting rod is c, the length of the frame is d, the distance from point E on the connecting rod plane to hinge B is e, and the angle between the line from hinge B to point E and the direction of the connecting rod is θ. E , the installation angle of the rack is θ D , the crank angle is θ A , the coordinate of the fixed hinge A is x A ,y A , the coordinates of the precision control points on the target trajectory are Then the Cartesian coordinates of point E on the connecting rod plane can be expressed as, x E =x A +a·cos(θ A +θ D )+e·cos(θ B +θ E +θ D ) y E =y A +a·sin(θ A +θ D )+e·sin(θ B +θ E +θ D ) in, It is characterized by the lengths of the four-bar pusher mechanism: a, b, c, d, the distance e from point E to hinge B, and the direction angle θ. E , the coordinate x of the fixed hinge A A ,y A , installation angle θ D , crank angle θ A , should satisfy the equation is the objective function, equation is the constrained optimization equation, where [γ0] is the allowable transmission angle.

[0005] Preferably, in the four-bar pusher mechanism, the length of the crank is 20 mm, the length of the connecting rod is 47 mm, the length of the connecting rod is 476 mm, the length of the frame is 476 mm, the distance from point E on the connecting rod plane to hinge B is 133 mm, the angle between the line from hinge B to point E and the direction of the connecting rod is -0.144 rad, the installation angle of the frame is 0.162 rad, and the x-axis coordinate x of the fixed hinge A of the crank is A Equal to 41mm, y-axis coordinate y A Equal to -112mm.

[0006] Preferably, in the four-bar pusher mechanism, the length of the crank is 31.9 mm, the length of the connecting rod is 280.9 mm, the length of the connecting rod is 133.5 mm, the length of the frame is 350 mm, the distance from point E on the connecting rod plane to hinge B is 367.6 mm, the angle between the line from hinge B to point E and the direction of the connecting rod is 0.052 rad, the installation angle of the frame is -0.853 rad, and the x-axis coordinate x of the fixed hinge A of the crank is A Equal to -293.3mm, y-axis coordinate y A Equal to -164.74mm.

[0007] The four-rod pushing mechanism of the present invention can make point E on the connecting rod plane move along a specified trajectory, use the straight line part in the trajectory to complete the pushing, and use the curved part in the trajectory to automatically avoid the material, thereby realizing high-speed pushing. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 , schematic diagram of the pushing mechanism working process.

[0009] Figure 2 , geometric parameter diagram of the four-bar pushing mechanism described in the present invention.

[0010] Figure 3 , the target motion trajectory diagram of the push head when the packaging object is GDX-1 type hard-pack small box cigarettes.

[0011] Figure 4 , when the packaging object is GDX-1 type hard pack small box cigarettes, the target motion trajectory of the push head and the motion trajectory of point E on the connecting rod plane.

[0012] Figure 5 , target motion trajectory diagram of the pusher head when the packaging objects are hard-packed slim cigarettes and small-box cigarettes.

[0013] Figure 6 , the target motion trajectory of the push head and the motion trajectory of point E on the connecting rod plane when the packaging objects are hard-packed slim cigarettes and small-box cigarettes. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] In the traditional four-bar mechanism design, when the analytical method is used to design the four-bar mechanism, the four-bar mechanism can only accurately fit 5 points. However, in some requirements, the four-bar mechanism is not required to accurately fit these precision control points. It is only required that a certain point on the connecting rod in the four-bar mechanism can move according to the specified target trajectory, and its error meets certain requirements. However, in the traditional four-bar mechanism analytical design method or drawing method, the precision control points are accurately fitted, which makes the traditional analytical design method or drawing method slightly insufficient in designing the four-bar mechanism according to the specified target trajectory. Therefore, in the present invention, by establishing the geometric equation of the four-bar mechanism, using the trajectory error of multiple precision control points on the target trajectory and a certain point on the connecting rod plane in the four-bar mechanism as the objective function, the geometric characteristics and motion characteristics of the four-bar mechanism are used as constraints, and the optimization equation is established. The design of the four-bar mechanism with a specified motion trajectory is realized by solving the optimization equation.

[0016] The geometric parameters of the four-bar pusher mechanism proposed by the present invention are as follows: Figure 2 As shown. It includes a crank 1, a connecting rod 2, a connecting rod 3 and a frame 4. The four hinges of the four-bar mechanism are A, B, C, and D respectively, and there is a specified point E on the connecting rod plane of the four-bar mechanism.

[0017] Assume that the length of crank 1 is a, the length of connecting rod 2 is b, the length of connecting rod 3 is c, the length of frame 4 is d, the distance from point E on the plane of connecting rod 2 to hinge B is e, and the angle between the line from hinge B to point E and the direction of connecting rod 2 is θ E , the installation angle of rack 4 is θ D , the rotation angle of crank 1 is θ A , the coordinate of the fixed hinge A of crank 1 is x A ,y A, the coordinates of the precision control point on the target trajectory are x p ,y p , then the Cartesian coordinates of point E on the connecting rod plane can be expressed as, x E =x A +a·cos(θ A +θ D )+e·cos(θ B +θ E +θ D ) y E =y A +a·sin(θ A +θ D )+e·sin(θ B +θ E +θ D ) in, The lengths of the four-rod pusher mechanism are a, b, c, d, the distance e from point E to hinge B, and the direction angle θ E , the coordinate x of the fixed hinge A of crank 1 A ,y A , installation angle θ D , crank angle θ A , should satisfy the equation is the objective function, equation is the constrained optimization equation, in which [γ0] is the allowable transmission angle. To ensure the transmission characteristics of the mechanism, the transmission angle [γ0] should be less than 30 degrees. When the transmission angle [γ0] is greater than 30 degrees, the transmission performance of the connecting rod mechanism decreases significantly.

[0018] When the packaging object is a GDX-1 type hard pack small box cigarette, the size of the four-rod pusher mechanism can be determined according to the above equation. The length, width and height of the GDX-1 type hard pack small box cigarette are 86mm, 54.86mm and 22.45mm respectively. According to the size of the cigarette box, the target motion trajectory of the pusher head 5 is determined as follows: Figure 3The target motion trajectory consists of three parts. The first part is a straight line part, which is used to control the push head 5 to move horizontally at a uniform speed; the second part is a short arc part, which is used to control the push head 5 to slowly descend to avoid the position of the cigarette pack changing due to the rapid descent speed; the third part is a long arc curve part, which is used to control the push head 5 to quickly retreat and pass over the cigarette pack 6. In order to achieve the above requirements, 20 precision control points are distributed on the target motion trajectory.

[0019] The motion trajectory between precision control points 2 to 7 is a horizontal straight line, and the distances between precision control points 2 to 7 are equal, which is used to control the push head to move horizontally at a uniform speed. The motion trajectory between precision control points 7 to 9 is a short arc line, which controls the push head 5 to separate slowly from the cigarette box to avoid lifting the cigarette pack due to too fast separation speed. The motion trajectory between precision control points 9 to 20 is a circular arc curve, which is used for the rapid retreat of the push head 5. Using the coordinates of the above precision control points and the established optimization equation of the four-bar pusher mechanism, it can be determined that the length of crank 1 is equal to 20mm, the length of connecting rod 2 is equal to 47mm, the length of connecting rod 3 is equal to 476mm, the distance from point E on the plane of connecting rod 2 to hinge B is equal to 133mm, the length of frame 4 is equal to 476mm, the angle between the line from hinge B to point E and the direction of connecting rod 2 is equal to -0.144rad, the installation angle of frame 4 is equal to 0.162rad, the x-axis coordinate of the fixed hinge A of crank 1 is equal to 41mm, and the y-axis coordinate is equal to -112mm.

[0020] Using the solved structural dimensions of the four-bar pusher mechanism, a motion simulation model is established, and the motion trajectory of point E on the connecting rod of the four-bar pusher mechanism is obtained as follows: Figure 4 As shown. Figure 4 It can be seen that the motion trajectory of point E on the connecting rod of the designed four-bar pusher mechanism can coincide well with the precision control point on the target trajectory, and the average error between the precision control points in the figure is only 1mm. This shows that the four-bar pusher mechanism designed by the above method can be used in the pusher work of GDX-1 type hard pack small box cigarettes.

[0021] When the packaging object is a hard-packed slim cigarette, since the size of the hard-packed slim cigarette box is large, the hard-packed slim cigarette and Tianxia small cigarette produced by Hunan China Tobacco Company are taken as examples to determine the size of the four-rod pusher mechanism according to the above equation. The length, width and height of the hard-packed slim cigarette and Tianxia small cigarette boxes are 101mm, 55mm and 12.7mm respectively. According to the size of the cigarette box, the target motion trajectory of the pusher head 5 is determined as follows: Figure 5 The trajectory shown.

[0022] The target motion trajectory consists of three parts. The first part is a straight line part, which is used to control the pusher head 5 to move horizontally at a uniform speed; the second part is a short arc part, which is used to control the pusher head 5 to lift up slowly to avoid the position of the cigarette pack changing due to the lifting speed being too fast; the third part is a long arc curve part, which is used to control the pusher head 5 to quickly retreat and pass over the cigarette pack. In order to achieve the above requirements, 20 precision control points are distributed on the target motion trajectory.

[0023] The motion trajectory between precision control points 2 to 7 is a horizontal straight line, and the distances between precision control points 2 to 7 are equal, which is used to control the push head 5 to move horizontally at a uniform speed. The motion trajectory between precision control points 7 to 9 is a short arc line, which controls the push head 5 to slowly separate from the cigarette box 2 to avoid lifting the cigarette box due to too fast separation speed. The motion trajectory between precision control points 9 to 20 is a circular arc curve, which is used for the rapid retreat of the push head. Using the coordinates of the above precision control points and the established optimization equation of the four-bar pusher mechanism, it can be determined that the length of crank 1 is 31.9 mm, the length of connecting rod 2 is 280.9 mm, the length of connecting rod 3 is 133.5 mm, the length of frame 4 is 350 mm, the distance from point E on the plane of connecting rod 2 to hinge B is 367.6 mm, the angle between the line between hinge B and point E and the direction of connecting rod 2 is 0.052 rad, the installation angle of frame 4 is -0.853 rad, the x-axis coordinate of the fixed hinge A of crank 1 is -293.3 mm, and the y-axis coordinate is -164.74 mm.

[0024] Using the solved structural dimensions of the four-bar pusher mechanism, a motion simulation model is established, and the motion trajectory of point E on the connecting rod of the four-bar pusher mechanism is obtained as follows: Figure 6 As shown. Figure 6 It can be seen that the motion trajectory of point E on the connecting rod of the designed four-bar pusher mechanism can be well matched with Figure 5 The precision control points on the target trajectory shown in the figure overlap, and the average error between the precision control points in the figure is only 1.2mm, indicating that the four-rod pushing mechanism designed according to the above method can be used for pushing hard-packed thin cigarettes and small-box cigarette boxes.

[0025] The above is a detailed description of the implementation of the present invention through specific embodiments in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation, and various changes can be made to it within the knowledge of ordinary technicians in this field. Therefore, the protection scope of the present invention is not limited to the above examples, and all technical solutions under the idea of ​​the present invention belong to the protection scope of the present invention.

Claims

1. A four-bar pusher mechanism for a cigarette packaging machine, comprising a crank (1), a connecting rod (2), a connecting rod (3) and a frame (4), wherein the length of the crank (1) is a, the length of the connecting rod (2) is b, the length of the connecting rod (3) is c, the length of the frame (4) is d, the distance from point E on the plane of the connecting rod (2) to hinge B is e, and the angle between the line from hinge B to point E and the direction of the connecting rod (2) is θ E , the installation angle of the frame (4) is θ D , the rotation angle of the crank (1) is θ A , the coordinates of the fixed hinge A of the crank (1) are x A ,y A , the coordinates of the precision control points on the target trajectory are Then the Cartesian coordinates of point E on the connecting rod (2) plane can be expressed as, x E =x A +a·cos(θ A +θ D )+e·cos(θ B +θ E +θ D ) y E =y A +a·sin(θ A +θ D )+e·sin(θ B +θ E +θ D ) in, It is characterized by the lengths of the four-bar pusher mechanism: a, b, c, d, the distance e from point E to hinge B, and the direction angle θ. E , the coordinate x of the fixed hinge A A ,y A , installation angle θ D , crank angle θ A , should satisfy the equation is the objective function, equation is the constrained optimization equation, where [γ0] is the allowable transmission angle.

2. The four-bar pusher mechanism according to claim 1, characterized in that: The length of the crank (1) is 20 mm, the length of the connecting rod (2) is 47 mm, the length of the connecting rod (3) is 476 mm, the length of the frame (4) is 476 mm, the distance from point E on the plane of the connecting rod (2) to the hinge B is 133 mm, the angle between the line from the hinge B to point E and the direction of the connecting rod (2) is -0.144 rad, the installation angle of the frame (4) is 0.162 rad, and the x-axis coordinate x of the fixed hinge A of the crank (1) is A Equal to 41mm, y-axis coordinate y A Equal to -112mm.

3. The four-bar pusher mechanism according to claim 1, characterized in that: The length of the crank (1) is 31.9 mm, the length of the connecting rod (2) is 280.9 mm, the length of the connecting rod (3) is 133.5 mm, the length of the frame (4) is 350 mm, the distance from point E on the plane of the connecting rod (2) to the hinge B is 367.6 mm, the angle between the line from the hinge B to point E and the direction of the connecting rod (2) is 0.052 rad, the installation angle of the frame (4) is -0.853 rad, and the x-axis coordinate x of the fixed hinge A of the crank (1) is A Equal to -293.3mm, y-axis coordinate y A Equal to -164.74mm.

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