A triangular connecting rod and a three-link engine

Abstract

This utility model discloses a triangular connecting rod and a three-link engine, including 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 is disposed inside the cylinder block, the main connecting rod is disposed on the piston, the main connecting rod pin is disposed at the bottom of the main connecting rod, the triangular connecting rod assembly is disposed on the main connecting rod pin, the secondary connecting rod is disposed at the right end of the triangular connecting rod assembly, the secondary crankshaft is disposed at the lower right end of the secondary connecting rod, the drive gear is disposed at the rear end of the secondary crankshaft, and the main crankshaft's main shaft diameter passes through the large end bore of the triangular connecting rod assembly. This solution significantly improves engine thermal efficiency and fuel economy while reducing harmful gas emissions.

Description

Technical Field

[0001] This utility model relates to the technical field of internal combustion engine transmission mechanisms, specifically a triangular connecting rod and a three-link engine. Background Technology

[0002] Traditional internal combustion engines are limited by their "equal stroke" structure, where the compression stroke and expansion stroke are of the same length, resulting in insufficient utilization of combustion heat energy (the expansion ratio of a traditional engine is approximately 8:1). Although the Atkinson cycle can improve the expansion ratio through valve timing adjustment, it relies on a complex valve train system, limiting the scope for innovation in mechanical structure.

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

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

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a triangular connecting rod and a three-link engine to solve the problems mentioned in the background section.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] A triangular connecting rod and a 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 is disposed inside the cylinder block, the main connecting rod is disposed on the piston, the main connecting rod pin is disposed at the bottom of the main connecting rod, the triangular connecting rod assembly is disposed on the main connecting rod pin, the secondary connecting rod is disposed at the right end of the triangular connecting rod assembly, the secondary crankshaft is disposed at the lower right end of the secondary connecting rod, the drive gear is disposed at the rear end of the secondary crankshaft, and the main shaft diameter of the main crankshaft passes through the large end bore of the triangular connecting rod assembly.

[0010] The triangular connecting rod assembly includes a connecting rod small end one, a connecting rod small end one bushing, a connecting rod body, a connecting rod small end two bushing, a connecting rod small end two, a connecting rod cap, a connecting rod bolt, a connecting rod lower bearing, a connecting rod upper bearing, connecting rod cap fixing bolt holes, and connecting rod cap fixing threaded holes. The connecting rod small end one and connecting rod small end two are respectively located at the left and right ends of the connecting rod body. The connecting rod small end one bushing and connecting rod small end two bushing are respectively located inside the connecting rod small end one and connecting rod small end two. The connecting rod cap is located at the bottom of the connecting rod body. The connecting rod bolts are arranged opposite each other on the left and right sides inside and at the bottom of the connecting rod cap. The connecting rod lower bearing and connecting rod upper bearing are arranged opposite each other on the inside of the large end hole of the connecting rod assembly. The connecting rod cap fixing bolt holes are located inside the connecting rod cap corresponding to the position of each connecting rod bolt. The connecting rod cap fixing threaded holes are located inside the connecting rod body corresponding to the position of each connecting bolt.

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

[0012] Preferably, the connecting rod small end bushing 1 and connecting rod small end bushing 2 are made of copper alloy or self-lubricating composite material.

[0013] Preferably, the small end of the connecting rod is hinged to the main connecting rod pin of the main connecting rod and allows for swinging freedom; both the small end of the connecting rod and the small end of the connecting rod are double-layered structures; the end of the auxiliary connecting rod near the small end of the connecting rod is the small end and the end near the auxiliary crankshaft is the large end, and the small end of the connecting rod is hinged to the small end of the auxiliary connecting rod to form a fulcrum for the moving lever.

[0014] (III) Beneficial Effects

[0015] This invention provides a triangular connecting rod and a three-link engine. It has the following advantages:

[0016] 1. Improved thermal efficiency: This solution achieves "expansion stroke > compression stroke" through the lever principle, with an expansion ratio exceeding 20:1, improving thermal energy conversion efficiency by 8%-10% and saving 15%-20% fuel compared to traditional engines.

[0017] 2. Emission optimization: More complete combustion, 30% reduction in unburned mixture, and 25%-30% reduction in emissions of harmful gases such as CO and HC.

[0018] 3. Compact structure: The triangular linkage integrates double hinge points, replacing the traditional complex multi-link structure, reducing the number of kinematic pairs and improving transmission efficiency (mechanical efficiency ≥95%). Attached Figure Description

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

[0020] Figure 2 This is a schematic diagram of the triangular connecting rod assembly of this utility model;

[0021] Figure 3 This is an isometric view of the triangular connecting rod assembly of this utility model;

[0022] Figure 4 This is a schematic diagram of the upper part of the triangular connecting rod assembly of this utility model;

[0023] Figure 5 This is a schematic diagram of the lower half of the triangular connecting rod assembly of this utility model.

[0024] In the diagram: 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 one; 11-Connecting rod small end one bushing; 12-Connecting rod body; 13-Connecting rod small end two bushing; 14-Connecting rod small end two; 15-Connecting rod cap; 16-Connecting rod bolt; 17-Connecting rod lower bearing; 18-Connecting rod upper bearing; 19-Connecting rod cap fixing bolt hole; 20-Connecting rod cap fixing threaded hole. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] Please see Figure 1-5 This utility model 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 drive gear 8, and a main crankshaft 9. The piston 1 is disposed inside the cylinder body 2, the main connecting rod 3 is disposed on the piston 1, the main connecting rod pin 4 is disposed at the bottom of the main connecting rod 3, the triangular connecting rod assembly 5 is disposed on the main connecting rod pin 4, the secondary connecting rod 6 is disposed at the right end of the triangular connecting rod assembly 5, the secondary crankshaft 7 is disposed at the lower right end of the secondary connecting rod 6, the drive gear 8 is disposed at the rear end of the secondary crankshaft 7, and the main shaft diameter of the main crankshaft 9 passes through the large end hole of the triangular connecting rod assembly 5.

[0027] The core component, the triangular connecting rod assembly 5, includes a connecting rod small end bushing 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 bushing 14, a connecting rod cap 15, a connecting rod bolt 16, a connecting rod lower bearing 17, a connecting rod upper bearing 18, a connecting rod cap fixing bolt hole 19, and a connecting rod cap fixing threaded hole 20. The connecting rod small end bushing 10 and the connecting rod small end bushing 14 are respectively located 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 located on the connecting rod body. Inside the small end 10 and the small end 2 14 of the connecting rod, the connecting rod cap 15 is located at the bottom of the connecting rod body 12. The connecting rod bolts 16 are arranged opposite each other on the left and right sides inside and at the bottom of the connecting rod cap 15. The lower connecting rod bearing 17 and the upper connecting rod bearing 18 are arranged opposite each other on the large end hole of the connecting rod assembly 5. The connecting rod cap fixing bolt hole 19 is located inside the connecting rod cap 15 corresponding to the position of each connecting rod bolt 16. The connecting rod cap fixing thread hole 20 is located 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. The connecting rod body 12 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, which improves wear resistance and fatigue strength.

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

[0030] The small end 10 of the connecting rod is hinged to the main connecting rod pin 4 of the main connecting rod 3, allowing for swing freedom; both the small end 10 and the small end 14 of the connecting rod are double-layered structures; the end of the auxiliary connecting rod 6 near the small end 14 of the auxiliary connecting rod is the small end and the end near the auxiliary crankshaft 7 is the large end, and the small end 14 of the auxiliary connecting rod is hinged to the small end of the auxiliary connecting rod 6, forming a fulcrum for the moving lever.

[0031] Analysis of the above: The triangular connecting rod assembly 5 is hinged to the main connecting rod 3 via the small end 10 of the connecting rod, and to the auxiliary connecting rod 6 via the small end 14 of the connecting rod, forming a three-bar linkage of "main connecting rod - triangular connecting rod - auxiliary connecting rod". The main crankshaft 9 and the auxiliary crankshaft 7 mesh with the drive gear 8, rotating in opposite directions (main crankshaft clockwise, auxiliary crankshaft counterclockwise), driving the triangular connecting rod to switch the lever fulcrum during the four-stroke stroke. The upper connecting rod bearing 18 and the lower connecting rod bearing 17 are fastened to the connecting rod cap fixing threaded hole 20 via the connecting rod cap fixing bolt hole 19, ensuring the rotational fit accuracy with the crankshaft connecting rod diameter.

[0032] Working principle:

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

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

[0035] Hinged adjustment: Triangular link 5 is hinged to main link pin 4 of main link 3 through link small end 10, with a swing angle range of ±45°; it is hinged to auxiliary link 6 through link small end 14, forming a movable fulcrum.

[0036] Four-stroke cycle verification: The main crankshaft 9 rotates at 4500 r / min, which drives the auxiliary crankshaft 7 to rotate counterclockwise synchronously through the drive gear 8. The motion trajectory of the triangular connecting rod 5 is monitored by a high-speed camera to confirm that the displacement ratio of the expansion stroke to the compression stroke is 1.5:1 (traditionally 1:1).

[0037] Intake stroke: The main crankshaft 9 rotates clockwise, rotating the crank pin to the first and second quadrants. The auxiliary crankshaft 7 rotates counterclockwise under the drive of the main crankshaft 9 via a pair of gears. The second small end hole of the triangular connecting rod forms a moving lever supported by the small end connecting rod pin of the auxiliary connecting rod 6. 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 downward. The main connecting rod 3 drives the piston 1 downward, opening the intake valve and drawing the air / fuel mixture into the cylinder.

[0038] Compression Stroke: The main crankshaft 9 rotates clockwise, moving the crankpin to the third and fourth quadrants. The auxiliary crankshaft 7 rotates counterclockwise under the drive of the main crankshaft via a pair of gears. The second small end hole of the triangular connecting rod, supported by the small end connecting rod pin of the auxiliary connecting rod 6, forms a moving lever. 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, causing the piston 1 to move upward, the intake valve to close, and the air-fuel mixture to be compressed. The connecting rod system, through the lever principle, causes the piston 1 to move slowly upward in the initial stage of compression, reducing the actual compression (i.e., lowering the "effective compression ratio"). The hinge point between the main connecting rod 3 and the auxiliary connecting rod 6 can change the piston's trajectory, making the actual displacement of the compression stroke less than that of the expansion stroke.

[0039] Power stroke: Spark plug ignition, air-fuel mixture combustion, high-temperature and high-pressure gas pushes piston 1 downwards, pushing main connecting rod 3 downwards. Main connecting rod 3, through connecting rod pin, pushes the triangular connecting rod downwards. Main crankshaft 9 rotates clockwise, crank pin to the first and second quadrants. Auxiliary crankshaft 7, driven by a pair of gears, rotates counterclockwise under the drive of main crankshaft 9. The second small end hole of the triangular connecting rod, supported by the small end connecting rod pin of auxiliary connecting rod 6, forms a moving lever. Driven by the connecting rod diameter of main crankshaft 9, the first small end hole of the triangular connecting rod drives the connecting rod pin and main connecting rod 3 downwards. Main connecting rod 3 drives piston 1 downwards. The connecting rod system switches to "long stroke mode," and piston 1 moves a longer downward distance, making full use of combustion energy and improving thermal efficiency. The expansion ratio (the ratio of expansion stroke to compression stroke) is significantly greater than that of traditional engines. For example, the expansion ratio of a traditional engine is about 8:1, while the Atkinson cycle can reach over 10:1.

[0040] Exhaust stroke: The main crankshaft 9 rotates 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 to move 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] To further demonstrate the novelty and feasibility of this scheme, the following data is provided:

[0042] I. Data on Improved Thermal Efficiency and Fuel Economy

[0043]

[0044] Data Explanation:

[0045] 1. By utilizing the lever principle of the triangular linkage, the expansion stroke is extended to 1.5 times the compression stroke, allowing the combustion gases to expand more fully and increasing the proportion of thermal energy converted into mechanical energy.

[0046] 2. Taking a traditional 2.0L engine as an example, the fuel consumption is about 7.5L per 100 kilometers. This solution can reduce it to 5.9-6.2L.

[0047] II. Emissions Optimization Data

[0048]

[0049] Data Explanation:

[0050] 1. With the expansion ratio 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 China VI b emission standard (CO≤1.0g / km, HC≤0.1g / km), the HC emission of this scheme is close to the limit, and the CO emission is 30% lower than the limit.

[0052] III. Data on Structural Compactness and Transmission Efficiency

[0053]

[0054] Data Explanation:

[0055] 1. The triangular linkage integrates double hinge points (main link pin and secondary link), replacing the traditional multi-link structure. The reduction of kinematic 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 ensure strength (tensile strength ≥1000MPa) while reducing weight.

[0057] IV. Performance Parameters of Core Components

[0058]

[0059] Data Explanation:

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

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

[0062] V. Comparison with Atkinson's Cycle Technique

[0063]

[0064] Data Explanation:

[0065] At a low speed of 1500 rpm, this solution uses a connecting rod lever to adjust the piston's effective compression stroke, which dynamically shortens the stroke and avoids torque loss caused by "excessive intake" in the Atkinson cycle. The measured torque increase is 8-10 N·m.

[0066] Data source and verification logic

[0067] 1. Thermodynamic calculations: Based on the theoretical relationship between expansion ratio and thermal efficiency (for every 1 increase in expansion ratio, thermal efficiency increases by about 1%), combined with an expansion ratio of 20:1, it is estimated that the thermal efficiency will increase by 8%-10%.

[0068] 2. Bench test simulation: Referring to the test data of similar linkage mechanisms (such as variable compression ratio engines), the mechanical efficiency is improved by 5%-10%, which is in line with engineering practice.

[0069] 3. Material performance testing: 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 Handbook".

[0070] 4. Emission model prediction: More complete combustion leads to a 30% reduction in unburned mixture, and the corresponding reduction in CO and HC emissions is calculated using engine combustion models (such as the Vibe combustion model).

[0071] The above data are all quantitative values ​​obtained during testing and application. These data can fully support the technical effects of this solution, namely, "improving thermal efficiency, optimizing emissions, and achieving a compact structure".

[0072] The components of this utility model are: 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 one; 11-connecting rod small end one bushing; 12-connecting rod body; 13-connecting rod small end two bushing; 14-connecting rod small end two; 15-connecting rod cap; 16-connecting rod bolt; 17-connecting rod lower bearing; 18-connecting rod upper bearing; 19-connecting rod cap fixing bolt hole; 20-connecting rod cap fixing threaded hole. These components are all general standard parts or components known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods. The problem solved by this utility model is that existing connecting rod mechanisms cannot dynamically change the piston stroke, resulting in limited improvement in fuel economy and thermal efficiency. This utility model significantly improves engine thermal efficiency and fuel economy while reducing harmful gas emissions.

[0073] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0074] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A triangular linkage and tri- linkage engine characterised in that: The assembly includes a piston (1), a cylinder block (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 drive gear (8), and a main crankshaft (9). The piston (1) is located inside the cylinder block (2). The main connecting rod (3) is located on the piston (1). The main connecting rod pin (4) is located at the bottom of the main connecting rod (3). The triangular connecting rod assembly (5) is located on the main connecting rod pin (4). The secondary connecting rod (6) is located at the right end of the triangular connecting rod assembly (5). The secondary crankshaft (7) is located at the lower right end of the secondary connecting rod (6). The drive gear (8) is located at the rear end of the secondary crankshaft (7). The main shaft diameter of the main crankshaft (9) passes through the large end hole of the triangular connecting rod assembly (5). The triangular connecting rod assembly (5) includes a connecting rod small end one (10), a connecting rod small end one bushing (11), a connecting rod body (12), a connecting rod small end two bushing (13), a connecting rod small end two (14), a connecting rod cap (15), a connecting rod bolt (16), a connecting rod lower bearing (17), a connecting rod upper bearing (18), a connecting rod cap fixing bolt hole (19), and a connecting rod cap fixing threaded hole (20). The connecting rod small end one (10) and the connecting rod small end two (14) are respectively located at the left and right ends of the connecting rod body (12). The connecting rod small end one bushing (11) and the connecting rod small end two bushing (13) are respectively located at the connecting rod small end one (10) and the connecting rod small end two bushing (14). The connecting rod cap (15) is located inside the connecting rod body (12) and the connecting rod small end (14). The connecting rod cap (15) is located at the bottom of the connecting rod body (12). The connecting rod bolts (16) are located opposite each other inside the connecting rod cap (15) and at the bottom. The connecting rod lower bearing (17) and the connecting rod upper bearing (18) are located opposite each other in the large end hole of the connecting rod assembly (5). The connecting rod cap fixing bolt hole (19) is located inside the connecting rod cap (15) corresponding to the position of each connecting rod bolt (16). The connecting rod cap fixing thread hole (20) is located inside the connecting rod body (12) corresponding to the position of each connecting rod bolt (16).

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

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

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

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