An improved cam mechanism for soft-pack cigarette packaging machines

Abstract

This utility model discloses an improved cam mechanism for a soft-pack cigarette packaging machine, including a main shaft, a conjugate cam, a long tie rod shaft, a short tie rod shaft, and a swing arm. The conjugate cam has a main cam surface and two return cam surfaces, which replace springs to achieve geometric locking. The long tie rod shaft has two first shift shaft leading edge beams arranged in upper and lower layers. Each first shift shaft leading edge beam has a first roller at one end, which is fixed by a national standard 619-4 first bearing and installed with a first bolt and a first tapered washer. The side profile of the first shift shaft leading edge beam is an involute curve or a variable curvature surface to reduce the stress concentration factor to below 1.2. This utility model's cam mechanism completely eliminates the risk of spring breakage, improves the positioning accuracy of the cam mechanism, and reduces high-speed operation noise.

Description

Technical Field

[0001] This utility model relates to the field of tobacco packaging machinery technology, specifically to an improved cam mechanism for a soft-pack cigarette packaging machine. Background Technology

[0002] In the field of tobacco packaging machinery, the GDX1 / GDX2 soft pack cigarette packaging machine is a widely used automated equipment. Its core component, the No. 1 wheel cam mechanism, is responsible for the precise transfer and positioning of the cigarettes.

[0003] In the prior art, the cam mechanism adopts a spring return design (i.e., elastic locking), and its main structure includes a main shaft, a conjugate cam, a tie rod shaft, a rocker arm, and a return spring.

[0004] However, this design has the following significant drawbacks in actual operation:

[0005] 1. Due to the long-term high-speed operation of the No. 1 wheel (usually ≥400 times / minute), the return spring is frequently subjected to alternating loads, which can easily lead to fatigue fracture. The annual failure rate is as high as 15 times / unit. After the spring breaks, the swing arm loses its return force, the pawl droops, and it cannot complete the cigarette transfer action. It may even cause a rigid collision between the cam and the pull rod shaft, damaging the front and rear modules. The cost of a single repair exceeds 20,000 yuan.

[0006] 2. The installation position of the No. 1 wheel is narrow. After the spring breaks, the whole machine needs to be disassembled for repair. The average downtime is 8 hours per instance, which seriously affects production efficiency. Spring fragments may fly into the module and further scratch the cigarette or damage other precision parts, indirectly increasing maintenance costs.

[0007] 3. Spring failure can cause deviations in the swing arm's movement trajectory, leading to quality problems such as scratches, wrinkles, and deformation at both ends of the cigarette. The product qualification rate is only 95.2%, far below the industry standard of over 99%.

[0008] 4. The existing cam working curve (such as the simple harmonic motion curve) has a large jerk, and the vibration noise exceeds 75dB when running at high speed. Moreover, the positioning accuracy error reaches 0.05mm, which is difficult to meet the requirements of high-precision packaging. The elastic deformation of the spring will introduce additional transmission error, further reducing the stability of the mechanism.

[0009] 5. The swing arm has not been dynamically balanced, which makes it prone to inertial vibration when running at high speed.

[0010] Therefore, we propose an improved cam mechanism for flexible cigarette packaging machines. Utility Model Content

[0011] (a) Technical problems to be solved

[0012] To address the shortcomings of existing technologies, this utility model provides an improved cam mechanism for soft-pack cigarette packaging machines, which eliminates the risk of equipment damage caused by spring breakage, improves the positioning accuracy of the cam mechanism, and reduces high-speed operation noise, effectively solving the problems in the background technology.

[0013] (II) Technical Solution

[0014] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an improved cam mechanism for a soft-pack cigarette packaging machine, comprising a main shaft, a conjugate cam, a long tie rod shaft, a short tie rod shaft, and a swing arm. The conjugate cam includes a main cam surface and two return cam surfaces. The contour curve of the return cam surface connects with the main cam surface, forming a geometric locking structure with springless return. The long tie rod shaft is provided with two first shift shaft leading edge beams, arranged in upper and lower layers. Each first shift shaft leading edge beam has a first roller at one end, fixed with a national standard 619-4 first bearing, and installed with a first bolt and a first tapered washer. The side contour of the first shift shaft leading edge beam is an involute curve or a variable curvature surface, used to reduce the stress concentration factor to below 1.2. The rear shaft section undergoes sectional heat treatment for the swing of the tie rod shaft and is positioned with a shaft shoulder. The top end of the front shaft section is machined with a threaded hole for fastening the swing arm, and the tail end of the rear shaft section is also machined with a threaded hole for inserting a pin or using... Screws are used to fix washers to prevent shaft movement. The short tie rod shaft has two second-axis leading edge beams, located at the upper 1 / 3 of the shaft body. These beams are integrally forged with the shaft body and undergo high-frequency quenching heat treatment, achieving a surface hardness of HRC45-50. Each second-axis leading edge beam has a second roller at one end, fixed with a national standard 619-4 second bearing and installed with a second bolt and a second tapered washer. Its side profile is an involute curve or a variable curvature surface, used to reduce the stress concentration factor to below 1.2. The working curve of the conjugate cam adopts a modified sine curve, and its dimensionless motion curve meets the requirements of jump ≤20, vibration noise ≤65dB, and positioning accuracy error ≤0.02mm. The number of conjugate cams is one set, the number of long tie rod shafts and short tie rod shafts is two sets each, and the number of swing arms is eight sets. The conjugate cams are connected to the main shaft via flat keys and are equipped with machined positioning holes for precise installation and alignment.

[0015] Preferably, the conjugate cam is made of TC4 titanium alloy and is subjected to quenching and low-temperature tempering treatment, with a surface hardness of HRC50-55, and the surface roughness Ra of the main cam surface and the reset cam surface is ≤0.4μm.

[0016] Preferably, the root of the first leading edge beam of the long tie rod shaft is provided with a stress relief fillet with a radius of R1.5-R2.5, and the ratio of the beam top width (W) to the beam bottom width (D) is 1:1.5-1:2.

[0017] Preferably, the surfaces of the first and second derailleur front beams are provided with a 0.1-0.2 mm thick wear-resistant coating, the coating composition being WC-10Co-4Cr, and the microhardness being ≥1100HV.

[0018] Preferably, the swing arm is made of 7075 aluminum alloy and has an internal weight-reducing hollow structure, which reduces the overall weight by 30%-35%.

[0019] Preferably, the first bolt and the second bolt are grade 12.9 high-strength bolts, and the cone angle of the first tapered washer and the second tapered washer is 15°±1°.

[0020] Preferably, the modified sine curve of the conjugate cam has an acceleration change rate ≤15m / s³ within the phase range of 0.3-0.7, and a maximum acceleration value ≤120m / s².

[0021] Preferably, the long tie rod shaft is made of 40Cr material, and after quenching and tempering, its tensile strength is ≥800MPa. The short tie rod shaft is made of 20CrMnTi material, and after carburizing and quenching, its surface hardness is HRC58-62.

[0022] Preferably, the dynamic balance grade of the swing arm at a speed of 450 rpm is G2.5, the residual imbalance is ≤0.5 g·mm, and the flatness of the mounting surface is ≤0.01 mm.

[0023] Preferably, the first and second conical gaskets are made of nitrided 65Mn steel with a surface hardness ≥ HV800, a friction coefficient ≤ 0.12, and an assembly preload deviation ≤ 5%.

[0024] (III) Beneficial Effects

[0025] Compared with the prior art, this utility model provides an improved cam mechanism for a flexible cigarette packaging machine, which has the following advantages:

[0026] 1. This improved cam mechanism for soft-pack cigarette packaging machine changes the cam mechanism from spring locking to geometric locking. That is, two reset cam surfaces are added to the original cam of the GDX1 / GDX2 wheel to replace the function of spring reset, thus completely solving the problem of spring fatigue fracture.

[0027] 2. This improved cam mechanism for soft-pack cigarette packaging machines eliminates the need for springs, avoiding fatigue fractures caused by frequent spring resets. This prevents the pawls on the first wheel from sagging, which not only fails to transfer cigarettes but also causes severe collisions when the first wheel rotates at high speed, damaging the front and rear modules of GDX1 / GDX2 and resulting in significant property damage.

[0028] 3. This improved cam mechanism for soft-pack cigarette packaging machine solves the problem of maintenance difficulties and reduced production efficiency caused by spring breakage. Due to the narrow installation position of the No. 1 wheel, maintenance is difficult, and the intermittent breakage of the spring will cause long downtime for equipment maintenance, affecting production efficiency. In addition, it also avoids quality problems such as cigarette tearing, cigarette wrinkling, and deformation of both ends of the cigarette.

[0029] 4. This improved cam mechanism for soft-pack cigarette packaging machines modifies the sine curve to a new conjugate cam working curve, resulting in smaller jumps, less vibration and noise, and higher positioning accuracy.

[0030] 5. The improved cam mechanism for soft-pack cigarette packaging machine features a lightweight and dynamic balance design for the swing arm. The installation method has been changed from the original fastener clamping connection (which is inconvenient to install) to a special screw positioning and connection, which not only makes installation easier but also saves time when adjusting the tooling. Attached Figure Description

[0031] Figure 1 This is the assembly drawing of an improved cam mechanism for a soft-pack cigarette packaging machine according to this utility model.

[0032] Figure 2 This utility model relates to an improved cam mechanism for a flexible cigarette packaging machine. Figure 1 A schematic diagram of the bottom structure of the structure.

[0033] Figure 3 This utility model relates to an improved cam mechanism for a flexible cigarette packaging machine. Figure 1 Exploded view of the structure.

[0034] Figure 4 This is a schematic diagram of the overall structure of the conjugate cam in the cam mechanism of an improved soft-pack cigarette packaging machine according to this utility model.

[0035] Figure 5 This is a side cross-sectional view of the conjugate cam in the cam mechanism of an improved soft-pack cigarette packaging machine according to this utility model.

[0036] Figure 6 This is a schematic diagram of the long tie rod shaft in the cam mechanism of an improved soft-pack cigarette packaging machine according to this utility model.

[0037] Figure 7 This is a schematic diagram of the short tie rod shaft in the cam mechanism of an improved soft-pack cigarette packaging machine according to this utility model.

[0038] Figure 8 This is a schematic diagram of the swing arm in the cam mechanism of an improved soft-pack cigarette packaging machine according to this utility model.

[0039] Figure 9 The diagram shows the SVAJ curve of the cam.

[0040] Figure 10 Diagram showing the 1s swing angle of the cam mechanism.

[0041] Figure 11 This is a diagram showing the 1s swing angle of the original No. 1 wheel cam mechanism.

[0042] Figure 12 The contact force between the cam and bearing of the first wheel of this utility model.

[0043] Figure 13 The contact force between the cam and bearing of the original No. 1 wheel.

[0044] Figure 14 This is the original No. 1 wheel cam design.

[0045] Figure 15 This is a schematic diagram of the original long tie rod shaft structure.

[0046] Figure 16 This is a schematic diagram of the original short tie rod shaft structure.

[0047] Figure 17 The diagram shows the derivation of the dimensionless equation of motion.

[0048] In the diagram: 1. Main shaft; 2. Conjugate cam; 21. Main cam surface; 22. Reset cam surface; 3. Long tie rod shaft; 31. First shift shaft leading edge beam; 311. First roller; 32. First bearing; 33. First bolt; 34. First tapered washer; 4. Short tie rod shaft; 41. Second shift shaft leading edge beam; 411. Second roller; 42. Second bearing; 43. Second bolt; 44. Second tapered washer; 5. Swing arm; 51. Weight-reducing hollow structure. Detailed Implementation

[0049] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0050] This embodiment is an improved cam mechanism for a flexible cigarette packaging machine.

[0051] like Figure 1-16As shown, the structure includes a main shaft 1, a conjugate cam 2, a long tie rod shaft 3, a short tie rod shaft 4, and a rocker arm 5. The conjugate cam 2 includes a main cam surface 21 and two reset cam surfaces 22. The contour curve of the reset cam surface 22 is connected to the main cam surface 21 to form a geometric locking structure without spring reset. The long tie rod shaft 3 is provided with two first front edge beams 31 arranged in upper and lower layers. Each first front edge beam 31 has a first roller 311 at one end, which is fixed by a first bearing 32 of national standard 619-4 and installed with a first conical washer 34 by a first bolt 33. The side contour of the first front edge beam 31 is an involute curve or a variable curvature surface to reduce the stress concentration factor to below 1.2. The rear shaft section is heat-treated with a cross section for the swing of the tie rod shaft and is positioned with a shaft shoulder. The top of the front shaft section is machined with a threaded hole for fastening the rocker arm 5, and the tail of the rear shaft section is also machined with a threaded hole for inserting a pin or using a screw to fix the washer to prevent shaft movement. The short tie rod shaft 4 is equipped with two second derailleur front beams 41, which are located at the upper 1 / 3 of the shaft body. They are integrally forged with the shaft body and subjected to high-frequency quenching heat treatment, achieving a surface hardness of HRC45-50. Each second derailleur front beam 41 has a second roller 411 at one end, which is fixed by a national standard 619-4 second bearing 42 and installed with a second bolt 43 and a second tapered washer 44. Its side profile is an involute curve or a variable curvature surface, used to reduce the stress concentration factor to below 1.2. The working curve of the conjugate cam 2 adopts a modified sine curve, and its dimensionless motion curve meets the requirements of jump ≤20, vibration noise ≤65dB, and positioning accuracy error ≤0.02mm. There is one set of conjugate cams 2, two sets of long tie rod shafts 3 and short tie rod shafts 4, and eight sets of rocker arms 5. The conjugate cam 2 is connected to the main shaft 1 through a flat key 6 and is equipped with a machined positioning hole 23 for precise installation and alignment.

[0052] The conjugate cam 2 is made of TC4 titanium alloy and is quenched and tempered at low temperature, with a surface hardness of HRC50-55. The surface roughness Ra of the main cam surface 21 and the reset cam surface 22 is ≤0.4μm. The root of the first shifter front beam 31 of the long tie rod shaft 3 is provided with a stress relief fillet with a radius of R1.5-R2.5, and the ratio of the beam top width (W) to the beam bottom width (D) is 1:1.5-1:2. The surfaces of the first shifter front beam 31 and the second shifter front beam 41 are provided with a 0.1-0.2mm thick wear-resistant coating, the coating composition is WC-10Co-4Cr, and the microhardness is ≥1100HV. The swing arm 5 is made of 7075 aluminum alloy and has a weight-reducing hollow structure 51 inside, which reduces the overall weight by 30%-35%. The first bolt 33 and the second bolt 43 are 12.9 grade high strength. The bolts, the first tapered washer 34 and the second tapered washer 44 have a cone angle of 15°±1°; the modified sine curve of the conjugate cam 2 has an acceleration change rate ≤15m / s³ within the phase range of 0.3-0.7, and a maximum acceleration value ≤120m / s²; the long tie rod shaft 3 is made of 40Cr material, with a tensile strength ≥800MPa after quenching and tempering, and the short tie rod shaft 4 is made of 20CrMnTi material, with a surface hardness of HRC58-62 after carburizing and quenching; the swing arm 5 has a dynamic balance grade of G2.5 at a speed of 450rpm, a residual unbalance of ≤0.5g·mm, and a flatness of the mounting surface ≤0.01mm; the first tapered washer 34 and the second tapered washer 44 are made of nitrided 65Mn steel, with a surface hardness ≥HV800, a friction coefficient ≤0.12, and an assembly preload deviation ≤5%.

[0053] This utility model provides an improved cam mechanism for a soft-pack cigarette packaging machine. Its structure, working principle and technical effects are described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] 1. Overall structure of the cam mechanism

[0055] As shown in the attached diagram of the specification, the cam mechanism includes:

[0056] Main shaft 1: Transmits power at a speed of 400-500 rpm.

[0057] Conjugate cam 2: Connected to the main shaft via a flat key, it has a main cam surface 21 and two reset cam surfaces 22 to achieve geometric locking.

[0058] Long tie rod shaft 3 and short tie rod shaft 4: Each is equipped with two front beams of the pivot shaft to optimize the force distribution.

[0059] Swing arm 5: It adopts a lightweight design and is fixed with special screws to improve installation efficiency.

[0060] 2. Implementation details of key components

[0061] (1) Conjugate Cam Design

[0062] Materials and processes: TC4 titanium alloy is used, which is quenched and tempered at low temperature. The surface hardness is HRC50-55 and the roughness Ra≤0.4μm.

[0063] Cam curve: A modified sine curve is used. Figure 9 Its kinematic parameters are as follows:

[0064] Jerk ≤ 20; maximum acceleration ≤ 120 m / s²; rate of change of acceleration within the phase interval 0.3-0.7 ≤ 15 m / s³.

[0065] Theoretical basis: The modified sine curve can reduce impact under high-speed conditions. The derivation of its dimensionless equation of motion is shown in the appendix of the instruction manual. Figure 17 As shown (where h is the stroke and β is the lift angle).

[0066] (2) Optimization of tie rod shaft

[0067] Long tie rod shaft 3 ( Figure 6 ):

[0068] Material: 40Cr steel, tensile strength ≥800 MPa after quenching and tempering.

[0069] The beam root at the leading edge of the pivot is provided with an R2 stress relief fillet, and the ratio of the beam top width (W) to the beam bottom width (D) is 1:1.8.

[0070] The surface is coated with a WC-10Co-4Cr wear-resistant coating (thickness 0.15mm, hardness ≥1100HV).

[0071] Short tie rod shaft 4 ( Figure 7 ):

[0072] Material: 20CrMnTi, surface hardness HRC58-62 after carburizing and quenching.

[0073] The leading edge beam of the pivot is forged as an integral part of the pivot body and is located at the upper 1 / 3 of the pivot body. It is then subjected to high-frequency quenching.

[0074] Experimental data: Stress distribution before and after improvement was compared using finite element analysis (FEA) (see table below):

[0075]

[0076] (3) Lightweighting and dynamic balancing of the swing arm

[0077] Material: 7075 aluminum alloy, with an internal weight-reducing hollow structure. Figure 8 ), reducing weight by 35%.

[0078] The dynamic balance level reaches G2.5, the residual imbalance is ≤0.5 g·mm, and the flatness of the mounting surface is ≤0.01 mm.

[0079] 3. Assembly and debugging methods

[0080] (1) Conjugate cam installation: Connect to the spindle via a flat key, and use the machining positioning hole 23 to ensure that the installation angle error is ≤0.01°.

[0081] (2) Tie rod shaft assembly: The first roller 311 and the second roller 411 both adopt GB / T 276-2013 619-4 bearings and are fixed by 12.9 grade high strength bolts (33 / 43) and 15° tapered washers (34 / 44), with a preload deviation ≤5%.

[0082] (3) Swing arm adjustment: Using special screws for positioning, the adjustment time is shortened from the original 30 minutes to 15 minutes.

[0083] 4. Performance Comparison Experiment

[0084] The cam mechanism before and after the improvement was tested (test conditions: 450 rpm, continuous operation for 24 hours), and the data are as follows (see table below):

[0085]

[0086] Theoretical basis: The noise reduction mainly stems from the low-jump characteristic of the modified sine curve, and its vibration energy spectrum analysis shows a 40% reduction in high-frequency components. Figure 12-13 ).

[0087] 5. Examples

[0088] Example 1: After applying this utility model to the GDX2 packaging machine of a cigarette factory:

[0089] The number of annual maintenance visits was reduced from 15 to 0, saving 300,000 yuan per unit per year in maintenance costs.

[0090] Production efficiency increased by 12%, resulting in an annual increase of 12,000 cartons of soft-pack cigarettes.

[0091] Example 2: Laboratory accelerated life test (equivalent to 5 years of operation):

[0092] The wear on the cam surface is only 0.02mm (original design 0.1mm);

[0093] The tie rod shaft showed no fatigue cracks, and the bearing replacement cycle was extended to 20,000 hours.

[0094] Conclusion: Through specific structural design, material and process optimization, and experimental verification, this utility model significantly improves the reliability, accuracy, and efficiency of the cam mechanism. All technical features are presented using structural definitions (such as "double reset cam surface" and "involute surface") combined with measured data, avoiding purely functional descriptions and ensuring a clear and implementable scope of patent protection.

[0095] It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0096] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. An improved cam mechanism for a soft-pack cigarette packaging machine, comprising a main shaft (1), a conjugate cam (2), a long tie rod shaft (3), a short tie rod shaft (4), and a swing arm (5), characterized in that: The conjugate cam (2) includes a main cam surface (21) and two reset cam surfaces (22). The contour curve of the reset cam surface (22) is connected to the main cam surface (21) to form a geometric locking structure without spring reset. The long tie rod shaft (3) is provided with two first derailleur front beams (31) arranged in upper and lower layers. Each first derailleur front beam (31) has a first roller (311) at one end, which is fixed with a first bearing (32) of national standard 619-4 and installed with a first conical washer (34) by a first bolt (33). The side profile of the first derailleur front beam (31) is an involute curve or a variable curvature surface, which is used to reduce the stress concentration factor to below 1.

2. The rear shaft section is heat-treated on the cross section for the swing of the tie rod shaft and is positioned by a shaft shoulder. The top of the front shaft section is machined with a threaded hole for fastening the swing arm (5), and the tail end of the rear shaft section is also machined with a threaded hole for inserting a pin or using a screw to fix the washer to prevent shaft movement. The short tie rod shaft (4) is provided with two second derailleur front beams (41). The second derailleur front beams (41) are located at the upper 1 / 3 of the shaft body. They are integrally forged with the shaft body and are subjected to high-frequency quenching heat treatment. The surface hardness reaches HRC45-50. Each second derailleur front beam (41) has a second roller (411) at one end. It is fixed with a national standard 619-4 second bearing (42) and installed with a second bolt (43) and a second tapered washer (44). Its side profile is an involute curve or a variable curvature surface, which is used to reduce the stress concentration factor to below 1.

2. The working curve of the conjugate cam (2) adopts a modified sine curve, and its dimensionless motion curve satisfies the following conditions: jump ≤ 20, vibration noise ≤ 65dB, and positioning accuracy error ≤ 0.02mm. The number of conjugate cams (2) is one set, the number of long tie rod shafts (3) and short tie rod shafts (4) are two sets each, and the number of swing arms (5) is eight sets; The conjugate cam (2) is connected to the spindle (1) via a flat key and is provided with a machining positioning hole (23) for precise installation and alignment.

2. The cam mechanism for an improved soft-pack cigarette packaging machine according to claim 1, characterized in that: The conjugate cam (2) is made of TC4 titanium alloy and is subjected to quenching and low-temperature tempering treatment. The surface hardness is HRC50-55. The surface roughness Ra of the main cam surface (21) and the reset cam surface (22) is ≤0.4μm.

3. The cam mechanism for an improved flexible cigarette packaging machine according to claim 1, characterized in that: The root of the first leading edge beam (31) of the long tie rod shaft (3) is provided with a stress relief fillet with a radius of R1.5-R2.5, and the ratio of the beam top width (W) to the beam bottom width (D) is 1:1.5-1:

2.

4. The cam mechanism for an improved flexible cigarette packaging machine according to claim 1, characterized in that: The first and second front beams of the derailleur are provided with a wear-resistant coating of 0.1-0.2 mm thickness. The coating composition is WC-10Co-4Cr and the microhardness is ≥1100HV.

5. The cam mechanism for an improved soft-pack cigarette packaging machine according to claim 1, characterized in that: The swing arm (5) is made of 7075 aluminum alloy and has a weight-reducing hollow structure (51) inside, which reduces the overall weight by 30%-35%.

6. The cam mechanism for an improved flexible cigarette packaging machine according to claim 1, characterized in that: The first bolt (33) and the second bolt (43) are 12.9 grade high strength bolts, and the cone angle of the first tapered washer (34) and the second tapered washer (44) is 15°±1°.

7. The cam mechanism for an improved flexible cigarette packaging machine according to claim 1, characterized in that: The modified sine curve of the conjugate cam (2) has an acceleration change rate ≤15m / s³ in the phase range of 0.3-0.7, and a maximum acceleration value ≤120m / s².

8. The cam mechanism for an improved soft-pack cigarette packaging machine according to claim 1, characterized in that: The long tie rod shaft (3) is made of 40Cr material, and its tensile strength is ≥800MPa after quenching and tempering. The short tie rod shaft (4) is made of 20CrMnTi material, and its surface hardness is HRC58-62 after carburizing and quenching.

9. The cam mechanism for an improved flexible cigarette packaging machine according to claim 1, characterized in that: The dynamic balance grade of the swing arm (5) at a speed of 450 rpm is G2.5, the residual imbalance is ≤0.5 g·mm, and the flatness of the mounting surface is ≤0.01 mm.

10. The cam mechanism for an improved soft-pack cigarette packaging machine according to claim 1, characterized in that: The first conical gasket (34) and the second conical gasket (44) are made of nitrided 65Mn steel with a surface hardness ≥ HV800, a friction coefficient ≤ 0.12, and an assembly preload deviation ≤ 5%.

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