Calculation method of force amplification ratio of five-point inclined elbow clamping mechanism

Abstract

The present invention provides a method for calculating the force amplification ratio of a five-point oblique elbow-type clamping mechanism. The five-point oblique elbow-type clamping mechanism includes two two-force components, which are respectively a first connecting rod and a second connecting rod. The method for calculating the force amplification ratio of the five-point oblique elbow-type clamping mechanism includes: performing force analysis on the first connecting rod and the second connecting rod respectively; solving the line of action RB of the first force on the first connecting rod, the line of action RD of the second force on the second connecting rod, and the line of action RO of the third force; and determining the force amplification ratio of the five-point oblique elbow-type clamping mechanism according to the force triangle formed by the line of action RB of the first force, the line of action RD of the second force on the second connecting rod, and the line of action RO of the third force. The technical solution provided by the present invention can solve the technical problem of large calculation deviation of the force amplification ratio of the five-point oblique elbow-type clamping mechanism in the prior art.

Description

Technical Field

[0001] The invention relates to the field of calculation of the force amplification ratio of a five-point oblique elbow-type clamping mechanism, and in particular to a method for calculating the force amplification ratio of a five-point oblique elbow-type clamping mechanism. Background Art

[0002] At present, the five-point oblique elbow-type clamping mechanism is a series mechanism of two offset rocker slider mechanisms that share a connecting rod. Its force amplification ratio is a key parameter for selecting clamping drive components. The calculation method under boundary lubrication conditions is: take the two-force rod component (front connecting rod L2 and small connecting rod L4) as the research object, and simplify the hinge force into two mutually perpendicular forces with the line of action passing through the rotation center. The line of action of one force is on the line connecting the two hinges of the two-force component, and its f times is the magnitude of the other force, and f is the friction coefficient. Ignoring the influence of the friction torque of the hinge, the equilibrium equation is established to obtain the formula for the force amplification ratio, which is the relationship between the rod length and the rod plane position angle.

[0003] However, ignoring the influence of the friction torque at the hinge is obviously not in line with reality and the results will be greatly deviated. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for calculating the force amplification ratio of a five-point oblique elbow clamping mechanism to solve the technical problem of large calculation deviation of the force amplification ratio of a five-point oblique elbow clamping mechanism in the prior art.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a method for calculating the force amplification ratio of a five-point oblique elbow clamping mechanism. The five-point oblique elbow clamping mechanism includes two two-force components, which are a first connecting rod and a second connecting rod respectively. The method for calculating the force amplification ratio of the five-point oblique elbow clamping mechanism includes: performing force analysis on the first connecting rod and the second connecting rod respectively; solving the line of action RB of the first force acting on the first connecting rod, the line of action RD of the second force acting on the second connecting rod, and the line of action RO of the third force; according to the force triangle formed by the line of action RB of the first force, the line of action RD of the second force acting on the second connecting rod, and the line of action RO of the third force, determining the length ratio of the line of action RB of the first force and the line of action RD of the second force.

[0006] Furthermore, the method for solving the line of action RB of the first force acting on the first connecting rod includes: obtaining the slope of the line of action RB of the first force according to the characteristic that the line of action of the force is tangent to the friction circle.

[0007] Furthermore, the method for solving the line of action RB of the first force acting on the first connecting rod also includes: obtaining the midpoint coordinates of the first connecting rod, and obtaining the straight line equation of the line of action RB of the first force according to the midpoint coordinates of the first connecting rod and the slope of the line of action RB of the first force.

[0008] Furthermore, the method for solving the line of action RD of the force acting on the second connecting rod includes: obtaining the slope of the line of action RD of the second force according to the characteristic that the line of action of the force is tangent to the friction circle.

[0009] Furthermore, the method for solving the line of action RD of the force acting on the second connecting rod also includes: obtaining the midpoint coordinates of the second connecting rod, and obtaining the straight line equation where the line of action RD of the second force is located according to the midpoint coordinates of the second connecting rod and the slope of the line of action RD of the second force.

[0010] Further, the method for determining the line of action RO of the third force includes: obtaining the slope of the line of action RO of the third force according to the characteristic that the line of action of the third force is tangent to the friction circle at the point O.

[0011] Furthermore, the method for determining the line of action RO of the third force also includes: solving the coordinates of the intersection E of the straight line where the line of action RB of the first force is located and the straight line where the line of action RD of the second force is located; solving the equation of the straight line where the line of action RO of the third force is located according to the coordinates of the intersection E and the slope of the line of action RO of the third force.

[0012] Furthermore, the method for determining the length ratio of the line of action RB of the first force to the line of action RD of the second force includes: obtaining the ratio of the line of action RB of the first force to the line of action RD of the second force according to the sine theorem of triangle.

[0013] Furthermore, after obtaining the ratio of the line of action RB of the first force to the line of action RD of the second force, the method for calculating the force amplification ratio of the five-point oblique elbow clamping mechanism also includes: according to the ratio of the line of action RB of the first force to the line of action RD of the second force, solving the ratio of the projection of the line of action RB of the first force in the horizontal direction to the projection of the line of action RD of the second force in the horizontal direction, the ratio of the projection of the line of action RB of the first force in the horizontal direction to the projection of the line of action RD of the second force in the horizontal direction is the force amplification ratio of the five-point oblique elbow clamping mechanism.

[0014] Furthermore, the formula for the force amplification ratio M obtained by solving the ratio of the projection of the line of action RB of the first force in the horizontal direction to the projection of the line of action RD of the second force in the horizontal direction is:

[0015]

[0016] By applying the technical solution of the present invention, by analyzing the forces of the two two-force components and solving the force triangle formed by RB, RD and RO, it is possible to accurately obtain the ratio of the projection of RB in the horizontal direction to the projection of RD in the horizontal direction, thereby obtaining the force amplification ratio. The above method is simple to solve and has high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 It shows the length and displacement parameter illustration diagram of the five-point oblique elbow clamping mechanism provided according to an embodiment of the present invention;

[0019] Figure 2 An angular parameter illustration diagram of a five-point oblique elbow clamping mechanism provided according to an embodiment of the present invention is shown;

[0020] Figure 3 It shows a force action illustration diagram of two two-force components of a five-point oblique elbow-type clamping mechanism provided according to an embodiment of the present invention;

[0021] Figure 4 A schematic structural diagram of a five-point oblique elbow clamping mechanism provided according to an embodiment of the present invention is shown (a single arrow in the figure indicates the elongation direction). Description of the drawings:

[0023] 10. Adjusting template; 20. Cross head; 30. Guide column; 40. First connecting rod; 50. Second connecting rod. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] like Figures 1 to 4 As shown ( Figure 1 , Figure 2 and Figure 3), an embodiment of the present invention provides a method for calculating the force amplification ratio of a five-point oblique elbow type clamping mechanism, the five-point oblique elbow type clamping mechanism includes two two-force components, the two two-force components are respectively a first connecting rod 40 and a second connecting rod 50, the method for calculating the force amplification ratio of the five-point oblique elbow type clamping mechanism includes: performing force analysis on the first connecting rod 40 and the second connecting rod 50 respectively; solving the line of action RB of the first force acting on the first connecting rod 40, the line of action RD of the second force acting on the second connecting rod 50 and the line of action RO of the third force; according to the force triangle formed by the line of action RB of the first force, the line of action RD of the second force acting on the second connecting rod 50 and the line of action RO of the third force, determining the force amplification ratio of the five-point oblique elbow type clamping mechanism. It should be noted that the third force is the force of the pin at position O on the triangle OAC connecting rod. Specifically, the structural schematic diagram of the five-point oblique elbow type clamping mechanism in this embodiment is as shown in the figure. Figure 4 As shown in , the five-point oblique elbow clamping mechanism includes an adjusting plate 10, a crosshead 20, a guide column 30, a first connecting rod 40 and a second connecting rod 50, and the crosshead 20 is a slider structure.

[0026] By adopting the calculation method of the force amplification ratio of the five-point oblique elbow clamping mechanism provided in this embodiment, the accurate selection of the clamping drive components is achieved at one time through the force triangle formed by RB, RD and RO. The force amplification ratio can be accurately calculated according to the length ratio of the line of action RB of the first force and the line of action RD of the second force, which is beneficial to the precise control of the clamping force in the injection compression process.

[0027] In this embodiment, the crosshead 20 moves rightward under the action of the driving force PO until the connecting rod OA (connecting rod OA is the first connecting rod 40) and the connecting rod AB (connecting rod AB is the second connecting rod 50) become a straight line. In this process, the guide column is extended, and the deformation force of the guide column is the clamping force Pm. The projection size of RB in the horizontal direction is equal to Pm, and the projection size of RD in the horizontal direction is equal to Po, so the ratio of the projection of RB in the horizontal direction to the projection of RD in the horizontal direction is the force amplification ratio.

[0028] Specifically, the method for solving the action line RB of the first force on the first connecting rod 40 includes: according to the characteristic that the action line of the force is tangent to the friction circle, obtaining the slope of the action line RB of the first force. With this method, when performing force analysis on the first connecting rod 40, the friction force is taken into account, which improves the accuracy of the force analysis and further improves the accuracy of the solution.

[0029] Specifically, through the formula Determine the friction circle, r is the radius of the friction circle, d is the pin diameter, and μ is the friction coefficient.

[0030] In this embodiment, the method for solving the line of action RB of the first force acting on the first connecting rod 40 further includes: obtaining the midpoint coordinates of the first connecting rod 40, and obtaining the equation of the line of action RB of the first force according to the midpoint coordinates of the first connecting rod 40 and the slope of the line of action RB of the first force. With this method, since RB passes through the midpoint position of the first connecting rod 40, it is convenient to accurately obtain the equation of the line of action RB.

[0031] Specifically, the method for solving the line of action RD of the force on the second connecting rod 50 includes: according to the characteristic that the line of action of the force is tangent to the friction circle, obtaining the slope of the line of action RD of the second force. With this method, when performing force analysis on the second connecting rod 50, the friction force is taken into account, which improves the accuracy of the force analysis and also better improves the accuracy of the solution.

[0032] In this embodiment, the method for solving the line of action RD of the force on the second connecting rod 50 further includes: obtaining the midpoint coordinates of the second connecting rod 50, and obtaining the straight line equation of the line of action RD of the second force according to the midpoint coordinates of the second connecting rod 50 and the slope of the line of action RD of the second force. With this method, since RD passes through the midpoint position of the second connecting rod 50, the accuracy of the force analysis of the second connecting rod 50 is improved, and the accuracy of the solution is further improved.

[0033] Specifically, the method for determining the line of action RO of the third force includes: obtaining the slope of the line of action RO of the third force according to the characteristic that the line of action of the third force is tangent to the friction circle at point O. By adopting such a method, the friction force is taken into account in the force analysis, which improves the accuracy of the force analysis and also better improves the accuracy of the force amplification ratio. Since the line of action RO is tangent to the friction circle at point O, the inclination angle h of the line of action of RO is obtained according to the slope of the tangent at a point outside the circle.

[0034] In this embodiment, the method for determining the line of action RO of the third force also includes: solving the coordinates of the intersection E of the straight line where the line of action RB of the first force is located and the straight line where the line of action RD of the second force is located; solving the equation of the straight line where the line of action RO of the third force is located according to the coordinates of the intersection E and the slope of the line of action RO of the third force.

[0035] Specifically, the method for determining the length ratio of the line of action RB of the first force and the line of action RD of the second force includes: obtaining the ratio of the line of action RB of the first force and the line of action RD of the second force according to the sine theorem of a triangle. In this method, the sine ratio of the side length and the corresponding angle in the sine theorem of a triangle is equal, and the length ratio of RB to RD is obtained. The method is simple and easy to solve.

[0036] After obtaining the ratio of the line of action RB of the first force to the line of action RD of the second force, the calculation method of the force amplification ratio of the five-point oblique elbow clamping mechanism further includes: according to the ratio of the line of action RB of the first force to the line of action RD of the second force, solving the ratio of the projection of the line of action RB of the first force in the horizontal direction to the projection of the line of action RD of the second force in the horizontal direction, the ratio of the projection of the line of action RB of the first force in the horizontal direction to the projection of the line of action RD of the second force in the horizontal direction is the force amplification ratio of the five-point oblique elbow clamping mechanism. The above method is simple to solve, easy to calculate, and has high accuracy.

[0037] Furthermore, the formula for the force amplification ratio M obtained by solving the ratio of the projection of the line of action RB of the first force in the horizontal direction to the projection of the line of action RD of the second force in the horizontal direction is:

[0038]

[0039] The specific solution method is as follows: Figure 1 , Figure 2 and Figure 3 , fix the origin of the rectangular coordinate system at point O, and use the force amplification ratio of point D in the first quadrant to illustrate, because the force amplification ratio at this time is more practical.

[0040] 1) Solve the midpoint coordinates of L4 and L2;

[0041] 2) Find the slope of the line where RB and RD lie;

[0042] 3) Use equations to represent the straight lines on which RB and RD lie;

[0043] 4) Solve the above equation to find the intersection point E; point E is also a point on the line of action of the RO force;

[0044] 5) Find the line of action of RO;

[0045] 6) Find the angle between RO and RD, and the angle between RO and RB;

[0046] 7) Use the triangle sine theorem to calculate the ratio of RB to RD, and then calculate the ratio of the horizontal projections of RB and RD, that is, the force amplification ratio.

[0047] The force amplification ratio obtained by this method is a relationship between the shaft diameter, rod length and rod plane position angle.

[0048]

[0049]

[0050] Find Sm from Sg:

[0051]

[0052]

[0053]

[0054] Sm=L1*cos(a+c)+L2*cos(a1);

[0055] Find Sg from Sm:

[0056]

[0057]

[0058] Sg=L5*cos(a+c+w)-L4*cos(b);

[0059]

[0060]

[0061]

[0062]

[0063] Point D (Sg, h2), point C (L5*cos(a+c+w), L5*sin(a+c+w)), midpoint of L4 ((L5*cos(a+c+w)+Sg) / 2, (L5*sin(a+c+w)+h2) / 2), then the equation of the line where RD lies is:

[0064]

[0065] Point B (Sm, h1), point A (L1*cos(a+c), L1*sin(a+c)), midpoint of L2 ((L1*cos(a+c)+Sm) / 2, (L1*sin(a+c+w)+h1) / 2), then the equation of the line where RB lies is:

[0066]

[0067] The coordinates of the intersection point E are:

[0068] x=(h2-h1-L1*sin(a+c)+Sg*tg(b-△b)+L5*sin(a+c+w)+Sm*tg(a1-△e)+L1*co s(a+c)*tg(a1-△e)+L5*tg(b-△b)*cos(a+c+w)) / (2*(tg(b-△b)+tg(a1-△e)))

[0069] y=(h1*tg(b-△b)+h2*tg(a1-△e)+Sg*tg(b-△b)*tg(a1-△e)-Sm*tg(b-△b)*tg(a1-△e)+L5*sin(a+c+w)*tg(a1-△e)+L1*sin( a+c)*tg(b-△b)-L1*cos(a+c)*tg(b-△b)*tg(a1-△e)+L5*tg(b-△b)*cos(a+c+w)*tg(a1-△e)) / (2*(tg(b-△b)+tg(a1-△e)));

[0070]

[0071] j=-a1+△e+h;

[0072] n=h+(b-△b);

[0073] From the triangle sine theorem we get:

[0074]

[0075] Therefore, the force amplification ratio is:

[0076]

[0077] a is the angle between L1 during mold closing and its position at the end of mold closing;

[0078] a1 is the angle between L2 and the horizontal line during the touching process;

[0079] b is the angle between L4 and the horizontal line;

[0080] c is the angle between L1 and the horizontal line at the end of mold closing;

[0081] w is the angle between L1 and L5;

[0082] h1 The vertical distance between the center of the hinge ear of the adjustment template 10 and the center of the hinge ear of the moving template;

[0083] h2 is the vertical distance between the center of the hinge ear of the crosshead 20 and the center of the hinge ear of the adjustment template 10;

[0084] Sg horizontal displacement of the center of the hinge ear of the crosshead 20 relative to the center of the hinge ear of the adjustment template 10;

[0085] Sm is the horizontal displacement of the movable template relative to the center of the hinge ear of the adjustment template 10;

[0086] d1 is the diameter of the A, B, and O pins;

[0087] d2 is the diameter of C and D pins;

[0088] r1 is the radius of the dynamic friction circle of the L1 and L2 hinges;

[0089] r2 is the radius of the dynamic friction circle of the L4 hinge;

[0090] u is the friction coefficient of the rotary pair;

[0091] h is the angle between the line of action of the force at point O and the horizontal direction;

[0092] j is the angle between the line of action of the force at point O and the line of action of the force at point B;

[0093] n is the angle between the line of action of the force at point O and the line of action of the force at point D.

[0094] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: accurate selection of clamping drive components is achieved at one time; and it is beneficial to achieve precise control of clamping force in the injection compression process.

[0095] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0096] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0097] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0098] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0099] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for calculating the force amplification ratio of a five-point oblique elbow clamping mechanism, characterized in that: The five-point oblique elbow-type clamping mechanism includes two two-force components, the two two-force components are respectively a first connecting rod and a second connecting rod. The calculation method of the force amplification ratio of the five-point oblique elbow-type clamping mechanism includes: Performing force analysis on the first connecting rod and the second connecting rod respectively; Solve the line of action RB of the first force acting on the first connecting rod, the line of action RD of the second force acting on the second connecting rod, and the line of action RO of the third force; The force amplification ratio of the five-point oblique elbow clamping mechanism is determined according to the force triangle formed by the action line RB of the first force, the action line RD of the second force on the second connecting rod, and the action line RO of the third force, including: According to the triangle sine theorem, obtain the ratio of the line of action RB of the first force to the line of action RD of the second force; According to the ratio of the action line RB of the first action force to the action line RD of the second action force, the ratio of the projection of the action line RB of the first action force in the horizontal direction to the projection of the action line RD of the second action force in the horizontal direction is solved, and the ratio of the projection of the action line RB of the first action force in the horizontal direction to the projection of the action line RD of the second action force in the horizontal direction is the force amplification ratio of the five-point oblique elbow clamping mechanism; The formula for the force amplification ratio M obtained by solving the ratio of the projection of the line of action RB of the first force in the horizontal direction to the projection of the line of action RD of the second force in the horizontal direction is: Among them, a1 is the angle between L2 and the horizontal line during the mold closing process, h is the angle between the force line at point O and the horizontal direction, j=-a1+△e+h, j is the angle between the force line at point O and the force line at point B, b is the angle between L4 and the horizontal line, n=h+(b-△b), n is the angle between the force line at point O and the force line at point D, L2 is the distance between point A and point B, and L4 is the distance between point C and point D.

2. The method for calculating the force amplification ratio of the five-point oblique elbow clamping mechanism according to claim 1 is characterized in that: The method for solving the line of action RB of the first force acting on the first connecting rod includes: According to the characteristic that the line of action of the force is tangent to the friction circle, the slope of the line of action RB of the first force is obtained.

3. The method for calculating the force amplification ratio of the five-point oblique elbow clamping mechanism according to claim 2 is characterized in that: The method for solving the line of action RB of the first force acting on the first connecting rod also includes: The midpoint coordinates of the first connecting rod are obtained, and the equation of the straight line on which the action line RB of the first action force is located is obtained according to the midpoint coordinates of the first connecting rod and the slope of the action line RB of the first action force.

4. The method for calculating the force amplification ratio of the five-point oblique elbow clamping mechanism according to claim 3 is characterized in that: The method for solving the line of action RD of the force acting on the second connecting rod includes: According to the characteristic that the action line of the force is tangent to the friction circle, the slope of the action line RD of the second action force is obtained.

5. The method for calculating the force amplification ratio of the five-point oblique elbow clamping mechanism according to claim 4 is characterized in that: The method for solving the line of action RD of the force acting on the second connecting rod also includes: The midpoint coordinates of the second connecting rod are obtained, and the equation of the straight line on which the action line RD of the second action force lies is obtained according to the midpoint coordinates of the second connecting rod and the slope of the action line RD of the second action force.

6. The method for calculating the force amplification ratio of the five-point oblique elbow clamping mechanism according to claim 5 is characterized in that: The method for determining the line of action RO of the third force comprises: According to the characteristic that the action line of the third action force is tangent to the friction circle at point O, the slope of the action line RO of the third action force is obtained.

7. The method for calculating the force amplification ratio of the five-point oblique elbow clamping mechanism according to claim 6 is characterized in that: The method for determining the line of action RO of the third force further includes: Solve for the coordinates of the intersection point E of the straight line where the line of action RB of the first acting force is located and the straight line where the line of action RD of the second acting force is located; The equation of the straight line on which the line of action RO of the third force lies is solved according to the coordinates of the intersection point E and the slope of the line of action RO of the third force.

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