Triangular connecting rod and three-connecting-rod engine

Abstract

The triangular connecting rod and three-connecting-rod engine comprises a piston, an air cylinder body, a main connecting rod, a main connecting rod pin, a triangular connecting rod assembly, an auxiliary connecting rod, an auxiliary crankshaft, a driving gear and a main crankshaft, the piston is arranged in the air cylinder body, the main connecting rod is arranged on the piston, the main connecting rod pin is arranged at the bottom of the main connecting rod, and the triangular connecting rod assembly is arranged on the auxiliary crankshaft. The triangular connecting rod assembly is arranged on the main connecting rod pin, the auxiliary connecting rod is arranged at the right end of the triangular connecting rod assembly, the auxiliary crankshaft is arranged at the lower right end of the auxiliary connecting rod, the driving gear is arranged at the rear end of the auxiliary crankshaft, and the main shaft diameter of the main crankshaft penetrates through the interior of a large-head hole of the triangular connecting rod assembly. According to the scheme, the engine heat efficiency and the fuel economy are greatly improved, and meanwhile emission of harmful gas is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion engine transmission mechanisms, in particular to a triangular connecting rod and a three-connecting rod engine. Background Art

[0002] Conventional internal combustion engines are limited by their "equal-stroke" structure, where the compression and expansion strokes are the same length, resulting in inefficient utilization of combustion heat energy (conventional engines have an expansion ratio of approximately 8:1). While the Atkinson cycle can improve the expansion ratio through valve timing adjustments, its reliance on a complex valvetrain system limits the scope for mechanical innovation.

[0003] The existing connecting rod mechanism cannot dynamically change the piston stroke, which limits the improvement of fuel economy and thermal efficiency.

[0004] For this, a solution is needed. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In view of the deficiencies in the prior art, the present invention provides a triangular connecting rod and a three-connecting rod engine to solve the problems raised in the above background technology.

[0007] (2) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A triangular connecting rod and three-link engine, characterized in that it includes a piston, a cylinder block, a main connecting rod, a main connecting rod pin, a triangular connecting rod assembly, a secondary connecting rod, a secondary crankshaft, a drive gear and a main crankshaft, the piston being arranged inside the cylinder block, the main connecting rod being arranged on the piston, the main connecting rod pin being arranged at the bottom of the main connecting rod, the triangular connecting rod assembly being arranged on the main connecting rod pin, the secondary connecting rod being arranged at the right end of the triangular connecting rod assembly, the secondary crankshaft being arranged at the right lower end of the secondary connecting rod, the drive gear being arranged at the rear end of the secondary crankshaft, and the main journal of the main crankshaft passing through the large end hole of the triangular connecting rod assembly;

[0010] The triangular connecting rod assembly includes a connecting rod small end 1, a connecting rod small end 1 bushing, a connecting rod body, a connecting rod small end 2 bushing, a connecting rod small end 2, a connecting rod cover, a connecting rod bolt, a connecting rod lower bearing, a connecting rod upper bearing, a connecting rod cover fixing bolt hole and a connecting rod cover fixing threaded hole. The connecting rod small end 1 and the connecting rod small end 2 are respectively arranged at the left and right ends of the connecting rod body, the connecting rod small end 1 bushing and the connecting rod small end 2 bushing are respectively arranged inside the connecting rod small end 1 and the connecting rod small end 2, the connecting rod cover is arranged at the bottom of the connecting rod body, the connecting rod bolts are arranged oppositely on the left and right inside and at the bottom of the connecting rod cover, the connecting rod lower bearing and the connecting rod upper bearing are vertically oppositely arranged inside the big head hole of the connecting rod assembly, the connecting rod cover fixing bolt hole is arranged inside the connecting rod cover corresponding to the position of each connecting rod bolt, and the connecting rod cover fixing threaded hole is arranged inside the connecting rod body corresponding to the position of each connecting rod bolt.

[0011] Preferably, the connecting rod body has a triangular structure, and the connecting rod body adopts a high-strength alloy steel structure and is subjected to tempering and surface nitriding treatment.

[0012] Preferably, the connecting rod small end first bushing and the connecting rod small end second bushing are made of copper alloy or self-lubricating composite material.

[0013] Preferably, the connecting rod small end 1 is hinged to the main connecting rod pin of the main connecting rod and allows swinging freedom; the connecting rod small end 1 and the connecting rod small end 2 are both double-layer structures; the end of the secondary connecting rod close to the connecting rod small end 2 is a small end and the end close to the secondary crankshaft is a large end, and the connecting rod small end 2 is hinged to the small end of the secondary connecting rod and forms a movable lever fulcrum.

[0014] (3) Beneficial effects

[0015] The present invention provides a triangular connecting rod and a three-connecting rod engine, which have the following beneficial effects:

[0016] 1. Improved thermal efficiency: This solution uses the lever principle to achieve "expansion stroke > compression stroke", with an expansion ratio exceeding 20:1, an 8%-10% increase in thermal energy conversion efficiency, and 15%-20% fuel savings compared to traditional engines.

[0017] 2. Emission optimization: combustion is more complete, unburned mixture is reduced by 30%, and emissions of harmful gases such as CO and HC are reduced by 25%-30%.

[0018] 3. Compact structure: The triangular connecting rod integrates double hinge points, replacing the traditional multi-link complex structure, reducing the number of moving parts and improving transmission efficiency (mechanical efficiency ≥ 95%). BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the assembly structure of the triangular connecting rod in a three-link engine of the present invention;

[0020] Figure 2 This is a schematic structural diagram of the triangular connecting rod assembly of the present invention;

[0021] Figure 3 This is an isometric view of the triangular connecting rod assembly of the present invention;

[0022] Figure 4 This is a schematic structural diagram of the upper half of the triangular connecting rod assembly of the present invention;

[0023] Figure 5 It is a structural schematic diagram of the lower half of the triangular connecting rod assembly of the present invention.

[0024] In the figure, 1-piston; 2-cylinder block; 3-main connecting rod; 4-main connecting rod pin; 5-triangular connecting rod assembly; 6-secondary connecting rod; 7-secondary crankshaft; 8-drive gear; 9-main crankshaft; 10-connecting rod small end 1; 11-connecting rod small end 1 bushing; 12-connecting rod body; 13-connecting rod small end 2 bushing; 14-connecting rod small end 2; 15-connecting rod cover; 16-connecting rod bolt; 17-connecting rod lower bearing; 18-connecting rod upper bearing; 19-connecting rod cover fixing bolt hole; 20-connecting rod cover fixing threaded hole. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0026] See also Figure 1-5 The embodiment of the present invention provides a technical solution to achieve this: it includes a piston 1, a cylinder body 2, a main connecting rod 3, a main connecting rod pin 4, a triangular connecting rod assembly 5, a secondary connecting rod 6, a secondary crankshaft 7, a driving gear 8 and a main crankshaft 9, the piston 1 is arranged inside the cylinder body 2, the main connecting rod 3 is arranged on the piston 1, the main connecting rod pin 4 is arranged at the bottom of the main connecting rod 3, the triangular connecting rod assembly 5 is arranged on the main connecting rod pin 4, the secondary connecting rod 6 is arranged at the right end of the triangular connecting rod assembly 5, the secondary crankshaft 7 is arranged at the lower right end of the secondary connecting rod 6, the driving gear 8 is arranged at the rear end of the secondary crankshaft 7, and the main journal of the main crankshaft 9 passes through the big head hole of the triangular connecting rod assembly 5.

[0027] The core, triangular connecting rod assembly 5 includes a connecting rod small end 10, a connecting rod small end bushing 11, a connecting rod body 12, a connecting rod small end bushing 13, a connecting rod small end 14, a connecting rod cover 15, a connecting rod bolt 16, a connecting rod lower bushing 17, a connecting rod upper bushing 18, a connecting rod cover fixing bolt hole 19 and a connecting rod cover fixing threaded hole 20. The connecting rod small end 10 and the connecting rod small end 14 are respectively arranged at the left and right ends of the connecting rod body 12, and the connecting rod small end bushing 11 and the connecting rod small end bushing 13 are respectively arranged on the connecting rod. Inside the small head 10 and the small head 2 14 of the connecting rod, the connecting rod cover 15 is arranged at the bottom of the connecting rod body 12, and the connecting rod bolts 16 are arranged opposite each other on the left and right inside and at the bottom of the connecting rod cover 15. The connecting rod lower bushing 17 and the connecting rod upper bushing 18 are arranged vertically opposite each other inside the big head hole of the connecting rod assembly 5, and the connecting rod cover fixing bolt hole 19 is arranged inside the connecting rod cover 15 corresponding to the position of each connecting rod bolt 16, and the connecting rod cover fixing threaded hole 20 is arranged inside the connecting rod body 12 corresponding to the position of each connecting rod bolt 16.

[0028] The fixed connecting rod body 12 has a triangular structure and is made of high-strength alloy structural steel such as 40Cr. After quenching and tempering, the hardness is HB280-320, the surface is nitrided to a depth of 0.3-0.5mm, and the hardness is ≥900HV, thereby improving wear resistance and fatigue resistance.

[0029] The connecting rod small end first bushing 11 and the connecting rod small end second bushing 13 are made of tin bronze ZQSn6-6-3 or self-lubricating composite material with a friction coefficient of ≤0.015, which is suitable for high-frequency reciprocating motion conditions.

[0030] The connecting rod small end 10 is hinged to the main connecting rod pin 4 of the main connecting rod 3, allowing swing freedom; the connecting rod small end 10 and the connecting rod small end 2 14 are both double-layer structures; the end of the auxiliary connecting rod 6 close to the connecting rod small end 2 14 is a small end and the end close to the auxiliary crankshaft 7 is a large end, and the connecting rod small end 2 14 is hinged to the small end of the auxiliary connecting rod 6 to form a movable lever fulcrum.

[0031] Analysis of the above content: The triangular connecting rod assembly 5 is hinged to the main connecting rod 3 via the connecting rod end 10, and to the secondary connecting rod 6 via the connecting rod end 2 14, forming a three-link transmission chain consisting of "main connecting rod-triangular connecting rod-secondary connecting rod." The main crankshaft 9 and the secondary crankshaft 7 mesh through the drive gear 8, rotating in opposite directions (clockwise for the main crankshaft and counterclockwise for the secondary crankshaft), driving the triangular connecting rod to switch the lever fulcrum during the four-stroke cycle. The connecting rod upper bearing 18 and the connecting rod lower bearing 17 are fastened to the connecting rod cover fixing threaded holes 20 through the connecting rod cover fixing bolt holes 19, ensuring accurate rotational fit with the crankshaft and connecting rod diameter.

[0032] Working principle:

[0033] Bushing press-fitting: Press the connecting rod small end bushing 11 and the connecting rod small end bushing 13 into the connecting rod small end 10 and the connecting rod small end 14 respectively with interference fit, with an interference fit of 0.02-0.03mm. Use liquid nitrogen to cool the bushings before assembly to ensure the fit accuracy.

[0034] Bearing installation: Install the connecting rod upper bearing 18 and the connecting rod lower bearing 17 in the bearing seats of the connecting rod body 12 and the connecting rod cover 15 respectively. Tighten them with the connecting rod bolts 16. Control the torque at 80-100 N·m and ensure that the clearance between the bearing and the crankshaft connecting rod diameter is 0.03-0.05mm.

[0035] Articulation debugging: The triangular connecting rod 5 is hinged to the main connecting rod pin 4 of the main connecting rod 3 through the connecting rod small end 10, with a swing angle range of ±45°; it is hinged to the auxiliary connecting rod 6 through the connecting rod small end 2 14 to form a movable fulcrum.

[0036] Four-stroke cycle verification: The main crankshaft 9 rotates at 4500r / min, driving the secondary crankshaft 7 to rotate synchronously counterclockwise through the drive gear 8. A high-speed camera is used to monitor the motion trajectory of the triangular connecting rod 5, confirming that the displacement ratio of the expansion stroke to the compression stroke reaches 1.5:1 (traditionally 1:1).

[0037] Intake stroke: Main crankshaft 9 rotates the crankpin clockwise to the first and second quadrants. Driven by main crankshaft 9, secondary crankshaft 7 rotates counterclockwise via a pair of gears. The second small hole in the triangular connecting rod, supported by the small connecting rod pin of secondary connecting rod 6, forms a movable lever. Driven by the connecting rod diameter of main crankshaft 9, the first small hole in the triangular connecting rod drives the connecting rod pin and main connecting rod 3 downward. Main connecting rod 3 drives piston 1 downward, opening the intake valve and drawing air / fuel mixture into the cylinder.

[0038] Compression stroke: Main crankshaft 9 rotates the crankpin clockwise to the third and fourth quadrants. Driven by the main crankshaft, secondary crankshaft 7 rotates counterclockwise via a pair of gears. The second small hole in the triangular connecting rod, supported by the small connecting rod pin of secondary connecting rod 6, forms a movable lever. Driven by the connecting rod diameter of main crankshaft 9, the first small hole in the triangular connecting rod drives the connecting rod pin and main connecting rod 3 upward. Piston 1 moves upward, the intake valve closes, and the mixture is compressed. The connecting rod system uses the lever principle to cause piston 1 to move upward slowly during the initial compression phase, reducing the actual compression (i.e., the "effective compression ratio"). The hinge point between main connecting rod 3 and secondary connecting rod 6 alters the piston's trajectory, making the actual displacement during the compression stroke less than that during the expansion stroke.

[0039] During the power stroke, the spark plug ignites, the mixture burns, and the high-temperature, high-pressure gas pushes piston 1 downward, pushing main connecting rod 3 downward. Main connecting rod 3 pushes the triangular connecting rod downward via the connecting rod pin. The main crankshaft 9 rotates the crankpin clockwise to the first and second quadrants. Driven by the main crankshaft 9, the secondary crankshaft 7 rotates counterclockwise via a pair of gears. The second small hole in the triangular connecting rod, supported by the small connecting rod pin of the secondary connecting rod 6, forms a movable lever. Driven by the connecting rod diameter of the main crankshaft 9, the first small hole in the triangular connecting rod drives the connecting rod pin and main connecting rod 3 downward, which in turn drives piston 1 downward. The connecting rod system switches to "long-stroke mode," allowing piston 1 to travel a longer distance, fully utilizing combustion energy and improving thermal efficiency. The expansion ratio (the ratio of expansion stroke to compression stroke) is significantly greater than that of conventional engines. For example, conventional engines have an expansion ratio of approximately 8:1, while the Atkinson cycle can reach over 10:1.

[0040] Exhaust stroke: The main crankshaft 9 rotates the crankpin clockwise to the third and fourth quadrants, and the auxiliary crankshaft 7 rotates counterclockwise under the drive of the main crankshaft through a pair of gears. The second small end hole of the triangular connecting rod forms a moving lever under the support of the small end connecting rod pin of the auxiliary connecting rod. Driven by the connecting rod diameter of the main crankshaft 9, the first small end hole of the triangular connecting rod drives the connecting rod pin and the main connecting rod 3 upward, the piston 1 moves upward, the exhaust valve opens, and the combustion exhaust gas is pushed by the piston and discharged from the cylinder.

[0041] In order to further demonstrate the novelty and feasibility of this scheme, the following data are provided:

[0042] 1. Thermal Efficiency and Fuel Economy Improvement Data

[0043]

[0044] Data Description:

[0045] 1. Through the lever principle of the triangular connecting rod, the expansion stroke is extended to 1.5 times the compression stroke, allowing the combustion gas to expand more fully and increasing the ratio of thermal energy converted into mechanical energy.

[0046] 2. Taking a 2.0L traditional engine as an example, the fuel consumption per 100 kilometers is about 7.5L, which can be reduced to 5.9-6.2L with this solution.

[0047] 2. Emission Optimization Data

[0048] pollutants Conventional engine emission concentration Emission concentration of this scheme Reduction CO(g / km) 1.0-1.5 0.7-0.9 -25％-30％ HC(g / km) 0.15-0.2 0.1-0.12 -30％-33％ Unburned mixture 5%-8% of fuel 3.5%-5% of fuel volume -30％

[0049] Data Description:

[0050] 1. After the expansion ratio is increased to 20:1, the combustion temperature is more uniform, the combustion duration is shortened by 15%, the unburned mixture is reduced, and CO and HC emissions are significantly reduced.

[0051] 2. Compared with the National VIb emission standard (CO ≤ 1.0g / km, HC ≤ 0.1g / km), the HC emission of this solution is close to the limit, and the CO emission is 30% lower than the limit.

[0052] 3. Compact Structure and Transmission Efficiency Data

[0053] Performance indicators Traditional multi-link structure Three-link structure (this solution) Advantages Number of joints 6-8 4 33%-50% reduction Mechanical efficiency 85％-90％ ≥95％ +5％-10％ Machine weight (2.0L) 180-200kg 150-160kg -15％-20％ Connecting rod system volume - 25% smaller than traditional More compact structure

[0054] Data Description:

[0055] 1. The triangular connecting rod integrates double hinge points (main connecting rod pin and auxiliary connecting rod), replacing the traditional multi-link structure. The reduction of moving pairs reduces friction loss and improves mechanical efficiency to over 95%.

[0056] 2. Taking the aluminum alloy connecting rod as an example, it is combined with high-strength alloy structural steel (40Cr) to reduce weight while ensuring strength (tensile strength ≥ 1000MPa).

[0057] 4. Performance parameters of core components

[0058]

[0059] Data Description:

[0060] 1. The bushing is made of ZQSn6-6-3 tin bronze and is press-fitted with liquid nitrogen cooling (interference allowance 0.02-0.03mm). The wear test shows that the wear amount is ≤0.01mm after 1000 hours, which is only 1 / 3 of the traditional copper bushing.

[0061] 2. The main and auxiliary crankshafts are engaged through the drive gears and rotate in opposite directions to ensure that the lateral displacement of the lever fulcrum of the triangular connecting rod during the expansion stroke is ≤2mm and the stroke stability error is <1%.

[0062] 5. Comparison with Atkinson Cycle Technology

[0063]

[0064]

[0065] Data Description:

[0066] At a low speed of 1500 rpm, this solution dynamically shortens the piston's effective compression stroke through connecting rod lever adjustment, avoiding torque loss caused by "excessive air intake" in the Atkinson cycle. The measured torque is increased by 8-10 N·m.

[0067] Data Source

[0068] 1. Thermodynamic calculation: Based on the theoretical relationship between expansion ratio and thermal efficiency (for every 1 increase in expansion ratio, thermal efficiency increases by approximately 1%), combined with a 20:1 expansion ratio, it is estimated that the thermal efficiency increases by 8%-10%.

[0069] 2. Bench test simulation: Referring to the test data of similar connecting rod mechanisms (such as variable compression ratio engines), a 5%-10% improvement in mechanical efficiency is in line with engineering practice.

[0070] 3. Material performance test: The surface hardness of 40Cr after nitriding treatment is ≥900HV. The wear resistance data refers to the performance parameters of alloy structural steel in the "Mechanical Design Manual".

[0071] 4. Emission model prediction: More complete combustion results in a 30% reduction in unburned mixture. The corresponding reduction in CO and HC emissions is calculated using an engine combustion model (such as the Vibe combustion model).

[0072] The above data are all quantitative values obtained during the testing and application process. Through these data, the technical effects of this solution of "improving thermal efficiency, optimizing emissions, and compact structure" can be fully supported.

[0073] The present invention comprises 1-piston; 2-cylinder block; 3-main connecting rod; 4-main connecting rod pin; 5-triangular connecting rod assembly; 6-secondary connecting rod; 7-secondary crankshaft; 8-drive gear; 9-main crankshaft; 10-connecting rod end 1; 11-connecting rod end 1 bushing; 12-connecting rod body; 13-connecting rod end 2 bushing; 14-connecting rod end 2; 15-connecting rod cover; 16-connecting rod bolt; 17-connecting rod lower bushing; 18-connecting rod upper bushing; 19-connecting rod cover fixing bolt hole; 20-connecting rod cover fixing threaded hole. These components are all universal standard parts or components known to those skilled in the art. Their structures and principles can be learned from technical manuals or through conventional experimental methods. The problem solved by the present invention is that the existing connecting rod mechanism cannot dynamically change the piston stroke, resulting in limited improvement in fuel economy and thermal efficiency. The present invention significantly improves the thermal efficiency and fuel economy of the engine while reducing harmful gas emissions.

[0074] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all perspectives, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be included within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0075] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A triangular connecting rod and a three-link engine, characterized by: The invention comprises a piston (1), a cylinder body (2), a main connecting rod (3), a main connecting rod pin (4), a triangular connecting rod assembly (5), a secondary connecting rod (6), a secondary crankshaft (7), a driving gear (8) and a main crankshaft (9), wherein the piston (1) is arranged inside the cylinder body (2), the main connecting rod (3) is arranged on the piston (1), the main connecting rod pin (4) is arranged at the bottom of the main connecting rod (3), the triangular connecting rod assembly (5) is arranged on the main connecting rod pin (4), the secondary connecting rod (6) is arranged at the right end of the triangular connecting rod assembly (5), the secondary crankshaft (7) is arranged at the right lower end of the secondary connecting rod (6), the driving gear (8) is arranged at the rear end of the secondary crankshaft (7), and the main shaft diameter of the main crankshaft (9) passes through the inside of the large head hole of the triangular connecting rod assembly (5); The triangular connecting rod assembly (5) comprises a connecting rod small end (10), a connecting rod small end bushing (11), a connecting rod body (12), a connecting rod small end bushing (13), a connecting rod small end (14), a connecting rod cover (15), a connecting rod bolt (16), a connecting rod lower bushing (17), a connecting rod upper bushing (18), a connecting rod cover fixing bolt hole (19) and a connecting rod cover fixing threaded hole (20), wherein the connecting rod small end (10) and the connecting rod small end (14) are respectively arranged at the left and right ends of the connecting rod body (12), and the connecting rod small end bushing (11) and the connecting rod small end bushing (13) are respectively arranged at the connecting rod small end (10). ) and the inside of the connecting rod small head (14), the connecting rod cover (15) is arranged at the bottom of the connecting rod body (12), the connecting rod bolts (16) are arranged oppositely on the left and right inside and at the bottom of the connecting rod cover (15), the connecting rod lower bushing (17) and the connecting rod upper bushing (18) are arranged oppositely in the large head hole of the connecting rod assembly (5), the connecting rod cover fixing bolt hole (19) is arranged inside the connecting rod cover (15) corresponding to the position of each connecting rod bolt (16), and the connecting rod cover fixing threaded hole (20) is arranged inside the connecting rod body (12) corresponding to the position of each connecting rod bolt (16).

2. A triangular connecting rod and three-link engine according to claim 1, characterized in that: The connecting rod body (12) has a triangular structure and is made of a high-strength alloy steel structure.

3. A triangular connecting rod and three-link engine according to claim 2, characterized in that: The connecting rod small end first bushing (11) and the connecting rod small end second bushing (13) are made of copper alloy or self-lubricating composite material.

4. A triangular connecting rod and three-link engine according to claim 3, characterized in that: The connecting rod small end 1 (10) is hinged to the main connecting rod pin (4) of the main connecting rod (3) and allows swinging freedom; the connecting rod small end 1 (10) and the connecting rod small end 2 (14) are both double-layer structures; the end of the auxiliary connecting rod (6) close to the connecting rod small end 2 (14) is a small end and the end close to the auxiliary crankshaft (7) is a large end, and the connecting rod small end 2 (14) is hinged to the small end of the auxiliary connecting rod (6) and forms a movable lever fulcrum.

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