Rotation type bottle blowing machine bottle taking and feeding cam contour design method based on model construction

Abstract

The invention discloses a method for designing a profile of a bottle taking and feeding cam of a rotary bottle blowing machine based on model construction. Relates to the technical field of bottle blowing machines. According to the method, the mathematical model of the manipulator is established, and the movement track of the palm of the manipulator is generated, so that the track curves of the swing cam and the direct-acting cam are directly generated, a traditional point drawing design mode is avoided, the design time is greatly shortened, and the design efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of bottle blowing machines, and in particular relates to a design method for a bottle picking and feeding cam profile of a rotary bottle blowing machine based on model construction. Background Art

[0002] The rotary bottle blowing machine has the characteristics of continuity, full automation, high speed and high efficiency, and has great development space in the beverage industry. However, the existing rotary bottle blowing machine designs mostly adopt the point drawing method, and the cam mechanism has large errors and insufficient smoothness, which makes the bottle blowing machine produce large noise during the production process, limiting the improvement of production efficiency. Summary of the invention

[0003] The purpose of the present invention is to provide a method for designing the contour of a bottle picking and feeding cam of a rotary bottle blowing machine based on model construction. By establishing a mathematical model of a manipulator, the motion trajectory of the palm of the manipulator is generated, thereby directly generating trajectory curves of a swing cam and a linear cam, avoiding the traditional point drawing design method, greatly shortening the design time, improving the design efficiency, and solving the problems raised by the background technology.

[0004] To solve the above technical problems, the present invention is achieved through the following technical solutions:

[0005] The present invention is a design method for the profile of a rotary bottle blowing machine bottle picking and feeding cam based on model construction, which includes the following steps:

[0006] Step 1: Establish a mathematical model to determine the trajectory equations of the manipulator at each stage;

[0007] Step 2: Input the main design parameters of the manipulator into the trajectory equation of step 1;

[0008] Step 3: Determine the connection points of each stage;

[0009] Step 4: Determine the distance between the center of the manipulator and the center of the mold;

[0010] Step 5: Determine the radial velocity curve and acceleration curve of the manipulator;

[0011] Step 6: Determine whether the requirements are met. If yes, proceed to step 7; otherwise, return to step 3.

[0012] Step 7: Output the robot trajectory curve and the swing and linear motion contour curves.

[0013] The present invention has the following beneficial effects:

[0014] 1. The present invention generates the motion trajectory of the palm of the manipulator by establishing a mathematical model of the manipulator, thereby directly generating the trajectory curves of the swing cam and the linear cam, avoiding the traditional point drawing design method, greatly shortening the design time and improving the design efficiency.

[0015] 2. The present invention uses formula calculation to accurately determine the connection point position of each stage and the distance between the center of the robot hand and the center of the mold, reducing the dependence on experience in the traditional design process and significantly reducing the design cost.

[0016] 3. The present invention avoids tedious manual calculation and verification steps by leveraging the powerful computing function of MATLAB, thus greatly improving the efficiency and accuracy of the design process.

[0017] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0019] Figure 1 This is a schematic diagram of the structure of the rotary bottle blowing machine of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the bottle taking and delivering cam of the present invention;

[0021] Figure 3 This is a working diagram of the bottle taking and delivering robot of the present invention;

[0022] Figure 4 This is a schematic diagram of the cooperation between the robot and the mold in the bottle taking stage of the present invention;

[0023] Figure 5 The second-order derivative variation curve of the synchronization segment θ close to the segment of the present invention;

[0024] Figure 6 This is a graph showing the relationship between the relative angular acceleration of the swing roller of the present invention;

[0025] Figure 7 This is a schematic diagram of the distance between the center of the manipulator and the center of the mold of the present invention;

[0026] Figure 8 The theoretical contour curve of the bottle taking and delivering cam of the present invention;

[0027] Fig. 9 This is a schematic structural diagram of the bottle taking and delivering robot of the present invention;

[0028] Fig.10 The present invention is designed as a method flow chart. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "all around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0031] like Figure 1 As shown in the figure: after the preform is heated by the heating box 15, it moves to the position of the preform cam 13 under the action of the conveyor belt 14, and then the preform is grabbed by the robot 12 arranged on the side of the preform cam 13 and placed in the mold 11 located on one side thereof; after the processing is completed under the action of the mold 11, the bottle body is taken out of the mold 11 by the bottle cam 16 arranged on one side of the mold 11 and the robot 12 arranged on the side of the bottle cam 16, and then placed in the bottle receiving tray 17 for transportation.

[0032] like Figure 2 and 9 The preform cam 13 and the bottle cam 16 have the same structure, both of which include a bottle cam disc 24, one side of which is provided with a swing cam groove 22 and a direct-acting cam groove 23, and one side of which is also rotatably provided with a driving disc 21; at the same time, the manipulator 12 includes a swing roller 25 and a direct-acting roller 26 respectively arranged in the swing cam groove 22 and the direct-acting cam groove 23, the swing roller 25 and the direct-acting roller 26 are respectively connected to two parts of a guide telescopic rod, and the end of the guide telescopic rod is provided with a manipulator body for clamping plastic bottles.

[0033] like Figure 3 , the trajectory of the manipulator is divided into four stages, namely, the bottle picking section, the transition section A34, the bottle feeding section and the transition section B37, wherein the bottle picking section includes the bottle picking approaching section 31, the bottle picking synchronous section 32 and the bottle picking exiting section 33; and the transition section A34 and the transition section B37 are both composed of a fifth-order polynomial-circular arc-fifth-order polynomial; the bottle feeding section is composed of a bottle feeding approaching section 35 and a bottle feeding exiting section 36; and Figure 3 A represents the motion trajectory of the robot 12 , B represents the motion trajectory of the bottle receiving tray 17 , and C represents the motion trajectory of the mold 11 .

[0034] like Fig.10 As shown, the present invention provides a method for designing a cam profile of a rotary bottle blowing machine based on model construction, comprising the following steps:

[0035] Step 1: Establish a mathematical model to determine the trajectory equations of the manipulator at each stage;

[0036] Step 2: Input the main design parameters of the manipulator into the trajectory equation of step 1;

[0037] Step 3: Determine the connection points of each stage;

[0038] Step 4: Determine the distance between the center of the manipulator and the center of the mold;

[0039] Step 5: Determine the radial velocity curve and acceleration curve of the manipulator;

[0040] Step 6: Determine whether the requirements are met. If yes, proceed to step 7; otherwise, return to step 3.

[0041] Step 7: Output the robot trajectory curve and the swing and linear motion contour curves.

[0042] The parameter equation of the bottle taking approach section is:

[0043]

[0044] Among them, the parameter equation of the bottle taking synchronization section is:

[0045]

[0046] Among them, the parameter equation of the bottle taking and exiting section is:

[0047]

[0048] Wherein, the parameter equations of the transition section A and the transition section B are:

[0049]

[0050] Among them, the parameter equation of the bottle delivery exit section is:

[0051]

[0052] Among them, the parameter equation of the bottle delivery exit section is:

[0053]

[0054] The equation for determining the swing cam trajectory parameters is:

[0055]

[0056] The parametric equation for determining the trajectory of the direct-acting cam is:

[0057]

[0058] Based on the above content, the parameters of the manipulator entered in step 2 are: driving rod radius R = 375mm, mold circle radius r1 = 1250mm, driving disk and mold circle center distance d1 = 1820mm, driving disk and mold circle transmission ratio i1 = 0.5, bottle receiving plate radius r2 = 180mm, driving disk and bottle receiving plate center distance d2 = 820mm, driving disk and bottle receiving plate transmission ratio i2 = 0.9, swing rod length N = 70mm, swing rod and linear rod angle ε = 2rad and linear roller distance from the manipulator center length m = 160mm.

[0059] At this time Figure 4 As shown in FIG. 1 , it is a schematic diagram of the cooperation between the robot 12 and the mold 11 in the bottle taking stage, that is, in the Figure 5 As shown, when the manipulator 12 enters the initial point D1 of the approaching segment, the first-order derivative value of the angle θ reaches the minimum, and the second-order derivative value approaches 0. Therefore, when the second-order derivative value of θ is 0, the manipulator 12 enters the bottle-taking approaching segment 31, and the corresponding driving angle at this time is φ1. In the process of the manipulator 12 entering and exiting the bottle-taking synchronous segment 32, the direction of θ changes in the opposite direction at φ=0. When the second-order derivative value of θ reaches the maximum and minimum values ​​respectively, the corresponding driving angles are φ2 and φ3 respectively. Due to different geometric conditions, the expressions of θ of the manipulator 12 in the bottle-taking exit segment 33 and the bottle-taking approaching segment 31 are different.

[0060] like Figure 6 As shown, when the manipulator 12 leaves the end point D4 of the bottle-taking exit section 33, the first-order derivative value of θ of the bottle-taking exit section 33 reaches the minimum, and the second-order derivative value approaches 0. Therefore, when the second-order derivative value of θ is 0, the manipulator 12 leaves the bottle-taking exit section 33, and the corresponding driving angle is φ4. The starting position of the bottle-taking approaching section 31 is φ1=1.32rad, the starting position of the bottle-taking synchronous section 32 is φ2=0.23rad, the end position of the bottle-taking synchronous section 32 is φ3=-0.27rad, the starting position of the bottle-taking exiting section 33 is φ4=-0.46rad, the starting position of the bottle-delivering approaching section 35 is φ1′=2.65rad, the end position of the bottle-delivering approaching section 35 is φ2′=2.50rad, the starting position of the bottle-delivering exiting section 36 is φ3′=2.30rad, and the transition section A34 and the transition section B37 are determined according to the positions of the two endpoints of the starting position φ1 and the starting position φ3′, and the transition section A34 and the transition section B37 are respectively divided into three equal parts for representation.

[0061] The present invention analyzes the relative angular acceleration of the swing roller and reasonably selects the positions of the connection points of the bottle picking section, effectively solving the problems of the robot action requirements and the overall running stability, and at the same time lays a foundation for the design of the integrated bottle picking and feeding cam curve.

[0062] The present invention adopts the design concept of "quintic polynomial-arc-quintic polynomial" in the transition section A34 and the transition section B37 of the manipulator, which effectively avoids interference between parts and solves the problem of sudden acceleration, so that the machine can run smoothly.

[0063] like Figure 7 As shown in the figure, the relationship between the distance S and S' between the center of the manipulator and the center of the mold and the driving angle φ determines the radial velocity and acceleration of the manipulator's linear actuator. In order to ensure that the manipulator can smoothly grasp the bottle, in the bottle approaching section 31, the radial velocity and radial acceleration of the manipulator 12 gradually decrease to 0 during the process from D1 to D2; and in the bottle exiting section 33, the radial velocity and radial acceleration of the manipulator 12 gradually decrease to 0 during the process from D4 to D3. Therefore, it is only necessary to determine the distance, radial velocity and acceleration between the manipulator's center and the center of the mold at D1 and D4 to calculate the relationship between the distance S and S' between the manipulator's center and the center of the mold and the driving angle φ.

[0064] The invention ensures the smooth operation of the manipulator in the process of taking bottles by designing and calculating the distance between the center of the manipulator and the center of the mold, and provides a new idea for the optimization of the subsequent cam curve for taking and delivering bottles.

[0065] like Figure 7 As shown in the figure, at point D1, a circular arc is drawn with point O as the center and OD2 as the radius. Assume that the circular arc is the motion trajectory of the approaching segment, and derive the relationship between the length of BC and the driving angle φ based on the geometric relationship.

[0066] Formula 1: And calculate S1 at the driving angle φ=φ1, as well as the first-order derivative value and the second-order derivative value as its radial velocity and acceleration.

[0067] Suppose S is a quintic polynomial function S(φ) with respect to φ, as shown in the following formula 2.

[0068]

[0069] Substitute the distance S, radial velocity and radial acceleration of the starting point of the approach segment into Formula 2 to solve the quintic polynomial function S(φ) of S with respect to the driving angle φ. Substitute S(φ) into Formula 1 to obtain the motion trajectory of the manipulator 12 in the bottle-taking approach segment 31. The trajectory of the manipulator 12 in the bottle-taking exit segment 33, the bottle-delivering approach segment 35 and the bottle-delivering exit segment 36 is also solved in the same way.

[0070] By using the powerful computing power of MATLAB, the above mathematical models of robot trajectory, swing and linear cam profile curves are input into MATLAB through programming, and the robot trajectory curve and swing and linear profile curves are calculated and output.

[0071] like Figure 8 As shown in the figure, it is the theoretical contour curve of the bottle picking and feeding cam. Figure 8 From the inside to the outside, there are the swing cam track, the translation cam track and the manipulator track.

[0072] The present invention takes the bottle feeding cam of 18-cavity rotary bottle blowing machine as the object, uses SolidWorks to carry out entity modeling, constructs the contour curves of the direct-acting and swinging cams, and verifies the effectiveness and applicability of the proposed method through Adams simulation. The results show that the cam mechanism contour generated by the proposed method has good consistency with the existing physical model, and the trajectory curve is smoother. Compared with the trajectory generated by the point drawing method, the speed and acceleration mutations are significantly reduced. Among them, the mutation points of the swing cam mechanism are reduced by 80%, the maximum acceleration is reduced by 48.42%, the mutation points of the direct-acting cam mechanism are reduced by 92.3%, the maximum acceleration is reduced by 5.63%, and the maximum driving torque is reduced by 42.01%. It proves that the proposed method has certain advantages in reducing acceleration and driving torque mutations, reducing system noise and improving running stability.

[0073] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0074] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A design method for the profile of a rotary bottle blowing machine bottle picking and feeding cam based on model construction, characterized in that: The steps include: Step 1: Establish a mathematical model to determine the trajectory equations of the manipulator at each stage; Step 2: Determine the theoretical equation of the distance between the center of the manipulator and the center of the mold; Step 3: Calculate the trajectory parameters of the robot center in the cam approach and exit segments. Step 4: The trajectory equation of the manipulator in the transition section is generated by setting convexity, selecting base circle and fitting polynomials; Step 5: Obtain the contour curve equation of the direct-acting and swinging cam through the robot palm trajectory equation.

2. The method for designing the profile of the rotary bottle blowing machine bottle picking and feeding cam based on model building according to claim 1 is characterized in that: The trajectory of the manipulator is divided into four stages, namely, a bottle picking section, a transition section A, a bottle delivery section and a transition section B, wherein the bottle picking section includes a bottle picking approach section, a bottle picking synchronization section and a bottle picking exit section; and the transition section A and the transition section B are both composed of a quintic polynomial-arc-quintic polynomial; the bottle delivery section is composed of a bottle delivery approach section and a bottle delivery exit section.

3. The method for designing the profile of the bottle picking and feeding cam of a rotary bottle blowing machine based on model construction according to claim 2 is characterized in that: The step 1 specifically includes establishing a bottle picking and delivering cam system model through analysis of the working principle of the rotary bottle blowing machine, studying the motion characteristics of the manipulator in the process of picking and delivering bottles, and deriving the vector equation of the manipulator's center in the approach segment, synchronization segment and exit segment of the bottle picking and delivering cam and the position of the segmentation points.

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