A fracture-resistant diesel engine crankshaft

Abstract

A diesel engine crankshaft for resisting fracture comprises a long journal, a left balancing block, a connecting rod journal, a right balancing block and a short journal, an oil slinger hole is provided on the connecting rod journal, the connecting rod journal is eccentrically arranged between the left balancing block and the right balancing block and is parallel to the long journal and the short journal, an oil introduction cone hole is provided on the right side of the oil slinger hole, the ratio of the diameter of the oil slinger hole to the diameter of the connecting rod journal is 1:(5-6), the ratio of the diameter of the oil slinger hole to the maximum diameter of the oil introduction cone hole is 1:(1 .5~1.6), the length of the oil guide cone hole is less than 0.5 of the length of the right balancing block, the axis of the radial lubricating oil hole is below the axis of the oil slinger hole, and the angle between the axis of the radial lubricating oil hole and the axis of the oil slinger hole is 30~90 degrees, the oil slinger hole is a stepped hole, which gradually increases from left to right. The smaller the aperture of the oil slinger hole in the connecting rod neck, the larger the solid cross-sectional area of ​​the connecting rod neck, the stronger the anti-shaft breakage ability of the crankshaft, and the crankshaft breakage rate can be reduced.

Description

Technical Field

[0001] The invention relates to a diesel engine accessory, in particular to a fracture-resistant diesel engine crankshaft. Background Art

[0002] The crankshaft is one of the most critical components in an engine. It receives the alternating driving force from the connecting rod and converts it into rotational torque, which is then output through the crankshaft to drive other engine components. The combined effects of the centrifugal force of the rotating mass, the periodically changing gas inertia, and the reciprocating inertia force subject the crankshaft to bending and torsional loads. Therefore, the crankshaft must possess sufficient strength and rigidity, and all journal surfaces must be wear-resistant, operate evenly, and be well-balanced. The existing diesel engine crankshaft consists of a long journal, a left balance block, a connecting rod neck, a right balance block and a short journal, and an oil slinger hole is provided on the connecting rod neck. Since the connecting rod neck is eccentrically arranged between the left balance block and the right balance block and is parallel to the long journal and the short journal, for a diesel engine of specific specifications, the geometric dimensions of the crankshaft connecting rod neck are limited. Providing a large-aperture oil slinger hole on the connecting rod neck directly reduces the radial solid cross-sectional dimensions of the connecting rod neck, thereby significantly reducing the connecting rod neck's shear and disassembly resistance. When the diesel engine is instantaneously overloaded, the crankshaft breaks at the connecting rod neck at a rate of 11% to 15%. How to solve the problem of connecting rod neck fracture is a technical problem of common concern to the entire diesel engine industry. Summary of the Invention

[0003] The object of the present invention is to provide a fracture-resistant diesel engine crankshaft which can ideally overcome the above-mentioned defects in the prior art.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A fracture-resistant diesel engine crankshaft, characterized in that it includes a long shaft neck, a left balancing block, a connecting rod neck, a right balancing block and a short shaft neck, an oil slinging ring hole is provided on the connecting rod neck, the connecting rod neck is eccentrically arranged between the left balancing block and the right balancing block, and is parallel to the long shaft neck and the short shaft neck, and characterized in that an oil introduction cone hole is provided on the right side of the oil slinging ring hole, the aperture b of the oil slinging ring hole is 3 to 12 mm, the ratio of the aperture b of the oil slinging ring hole to the maximum aperture c of the oil introduction cone hole is b:c=1:(1.3 to 1.6), the length d of the oil introduction cone hole is less than 0.5D of the length of the right balancing block, that is, d<0.5D, a radial lubricating oil hole is provided on the connecting rod neck, the axis of the radial lubricating oil hole is below the horizontal axis of the oil slinging ring hole, the radial lubricating oil hole consists of an inner oil channel hole and an exposed chamfered hole, the diameter of the inner oil channel hole is 1 to 3 mm, and the exposed chamfered hole is arranged on the outside of the inner oil channel hole.

[0006] Furthermore, the aperture b of the oil slinger hole is 5 to 9 mm, the ratio of the aperture b of the oil slinger hole to the maximum aperture c of the oil inlet cone hole is b:c=1:(1.45 to 1.5), and the length d of the oil inlet cone hole is 0.3 to 0.45 times the length of the right balance block.

[0007] Furthermore, the ratio of the diameter b of the oil slinger hole to the maximum diameter c of the oil guide cone hole is b:c=1:1.5, and the length d of the oil guide cone hole is 0.36 times the length D of the right balance block.

[0008] Furthermore, the angle between the axis of the radial lubricating oil hole and the horizontal axis of the oil slinger hole is 0 to 180 degrees.

[0009] Furthermore, the angle between the axis of the radial lubricating oil hole and the horizontal axis of the oil slinger hole is 60 to 120 degrees.

[0010] Furthermore, the axis of the radial lubricating oil hole is perpendicular to the horizontal axis of the oil slinger hole.

[0011] Furthermore, the oil slinger hole is a stepped hole, which gradually increases from left to right.

[0012] Furthermore, the diameter of the left hole of the stepped hole is 2 to 5 mm, and the diameter of the right hole is 1 to 3 mm larger than that of the left hole.

[0013] Since this solution improves the structure of the oil slinger hole on the connecting rod neck, the single large-diameter oil slinger hole is designed as a stepped hole with a small oil channel aperture in the connecting rod neck and a large oil channel aperture at the right balance block. This does not affect the amount of lubricating oil entering, and increases the radial solid cross-sectional area of ​​the connecting rod neck, thereby greatly enhancing the fracture resistance of the connecting rod neck. When the diesel engine is instantaneously overloaded, the frequency of crankshaft fracture at the connecting rod neck can be greatly reduced. If the oil slinger hole in the connecting rod neck is set as a stepped hole, the aperture gradually increases from left to right, which can further increase the solid cross-sectional area of ​​the connecting rod neck. The smaller the aperture of the oil slinger hole in the connecting rod neck, the stronger the fracture resistance.

[0014] The radial lubricating oil holes on the connecting rod neck are repositioned, moving them above the horizontal axis of the oil slinger hole, in a weaker area on the connecting rod neck. This prevents further weakening of the connecting rod neck at its weakest point, the oil slinger hole, thereby improving the connecting rod neck's fracture resistance. The radial lubricating oil holes are located between the inner rails of the left and right balance weights, with the axis of the radial lubricating oil holes perpendicular to the axes of the long and short journals. This is the optimal position for the connecting rod neck's fracture resistance. The radial lubricating oil holes are designed to consist of an inner oil passage hole with a diameter of 1 to 3 mm and an exposed chamfered hole located outside the inner oil passage hole. This improves the connecting rod neck's fracture resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of an existing crankshaft;

[0016] Figure 2 for Figure 1 Cross-sectional view of AA;

[0017] Figure 3 It is a structural schematic diagram of the present invention;

[0018] Figure 4 Schematic diagram of Example 2;

[0019] Figure 5 Schematic diagram of Example 3;

[0020] Figure 6 Schematic diagram of Example 4;

[0021] In the figure: 1-long journal; 2-left balancing block; 3-connecting rod journal; 4-right balancing block; 5-short journal; 6-oil slinger hole; 7-oil inlet cone hole; 8-lubricating oil hole; 81-inner oil channel hole; 82-exposed chamfered hole; a-diameter of connecting rod journal; b-aperture of oil slinger hole; c-maximum aperture of oil inlet cone hole; d-length of oil inlet cone hole; D-length of right balancing block. DETAILED DESCRIPTION

[0022] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0023] Example 1:

[0024] On the single-cylinder water-cooled diesel engine with a cylinder diameter of 88 mm that the applicant has successfully developed, the fracture-resistant diesel engine crankshaft of the present invention, such as Figure 3As shown, it includes a long journal 1, a left balancing block 2, a connecting rod journal 3, a right balancing block 4, a short journal 5, and an oil ring hole 6. The left balancing block 2 is provided on the right side of the long journal 1, and the right balancing block 4 is provided on the left side of the short journal 5. The left balancing block 2 and the right balancing block 4 are fixedly connected by the connecting rod journal 3. The axis of the connecting rod journal 3 deviates from the axis between the long journal 1 and the short journal 5 by 40 mm, that is, the eccentricity is 40 mm, and the axis of the connecting rod journal 3 is parallel to the axis of the long journal 1 and the short journal 5. The short journal 5 is fixedly connected to the right side of the right balancing block 4. The oil slinger hole 6 is located at the upper end of the connecting rod journal 3 and the right balance weight 4, with the left side higher and the right side lower. An oil guide cone hole 7 is provided at the right end of the oil slinger hole 6. The diameter of the long journal 1 is 50 mm and the length is 89 mm. The length of the left balance weight 2 is 26 mm. The diameter of the connecting rod journal 3 is 46 mm. The length D of the right balance weight 4 is 27.5 mm. The diameter of the short journal is 50 mm and the length is 19.5 mm. The diameter b of the oil slinger hole 6 is 9 mm. The maximum diameter c of the oil guide cone hole 7 is 14.2 mm. The length d of the oil guide cone hole 7 is 10 mm. The radial lubricating oil hole 8 consists of an inner oil channel hole 81 and an exposed chamfered hole 82. The diameter of the inner oil channel hole 81 is 1 to 3 mm. The exposed chamfered hole 82 is provided on the outside of the inner oil channel hole 81. In this way, the connecting rod journal 3 has better fracture resistance.

[0025] Example 2:

[0026] In Example 1, a radial lubricating oil hole 8 is provided on the connecting rod neck 3 and communicates with the oil slinger hole 6. The axis of the radial lubricating oil hole 8 is below the axis of the oil slinger hole 6. The oil slinger hole 6 is a stepped hole that gradually increases from left to right. The diameter of the left hole of the stepped hole is 5 mm, and the diameter of the right hole is 9 mm. Figure 4 shown.

[0027] Example 3:

[0028] The difference from Example 2 is that a radial lubricating oil hole 8 communicating with the oil slinger hole 6 is provided on the connecting rod neck 3. The axis of the radial lubricating oil hole 8 is below the horizontal axis of the oil slinger hole 6, and the angle between the axis of the radial lubricating oil hole 8 and the horizontal axis of the oil slinger hole 6 is 45 degrees. Figure 5 shown.

[0029] Example 4:

[0030] The difference from Example 2 is that a radial lubricating oil hole 8 is provided on the connecting rod neck 3 and communicates with the oil slinger hole 6. The axis of the radial lubricating oil hole 8 is below the horizontal axis of the oil slinger hole 6 and is perpendicular to the horizontal axis of the oil slinger hole 6. This position is the best position. Figure 6 shown.

[0031] The principles of the present invention are as follows:

[0032] The present invention improves the oil slinger hole 6 opened on the connecting rod neck 3, and designs the single large-diameter oil slinger hole 6 into a stepped hole with a small oil passage aperture in the connecting rod neck 3 and a large oil passage aperture in the balance block. This does not affect the amount of lubricating oil entering, and increases the radial solid cross-sectional size of the connecting rod neck 3, thereby greatly reducing and enhancing the shear resistance and anti-fracture performance of the connecting rod neck 3. When the diesel engine is instantaneously overloaded, the frequency of the crankshaft breaking at the connecting rod neck 3 is greatly reduced. If the oil slinger hole 6 in the connecting rod neck 3 is set as a stepped hole, with the aperture gradually decreasing from left to right, the radial solid cross-sectional size of the connecting rod neck 3 can be further increased, and the anti-fracture performance is better.

[0033] Since the existing radial lubricating oil hole 8 is arranged above the horizontal axis of the oil slinger hole 6, this is the place where the solid wall thickness of the crankshaft connecting rod neck 3 is the smallest, that is, the weakest part, opening the radial lubricating oil hole 8 here will further weaken the strength here, thereby increasing the probability of the crankshaft breaking during operation. This solution arranges the radial lubricating oil hole 8 below the horizontal axis of the oil slinger hole 6, so as to avoid the weakest area of ​​the connecting rod neck 3. According to the lubrication principle and structural strength optimization design, the aperture of the lubricating oil hole 8 here should be reduced to 1 to 3 mm. Such a comprehensive solution can maximize the anti-fracture strength of the connecting rod neck 3, eliminate and maximize the reduction of the crankshaft connecting rod neck 3 breakage rate, and ideally overcome the defects of the existing technology.

[0034] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A fracture-resistant diesel engine crankshaft, comprising a long journal (1), a left balancing block (2), a connecting rod journal (3), a right balancing block (4) and a short journal (5), wherein an oil slinging ring hole (6) is provided on the connecting rod journal (3), wherein the oil slinging ring hole (6) is provided at the upper end of the connecting rod journal (3) and the right balancing block (4), and the left one is higher than the right one. The oil slinging ring hole (6) is a stepped hole, gradually increasing in size from left to right. The connecting rod journal (3) is eccentrically provided between the left balancing block (2) and the right balancing block (4), and is parallel to the long journal (1) and the short journal (5). The invention is characterized in that: An oil introduction cone hole (7) is provided on the right side of the oil slinging ring hole (6). The diameter b of the oil slinging ring hole (6) is 3 to 12 mm. The ratio of the diameter b of the oil slinging ring hole (6) to the maximum diameter c of the oil introduction cone hole (7) is b:c=1:(1.3 to 1.6). The length d of the oil introduction cone hole (7) is less than 0.5D of the length of the right balance block (4), that is, d<0.5D. A radial lubricating oil hole (8) communicating with the oil slinging ring hole (6) is provided on the connecting rod neck (3). The axis of the radial lubricating oil hole (8) is below the horizontal axis of the oil slinging ring hole (6) to avoid the weakest area of ​​the connecting rod neck (3). The radial lubricating oil hole (8) consists of an inner oil channel hole (81) and an exposed chamfered hole (82). The diameter of the inner oil channel hole (81) is 1 to 3 mm, and the exposed chamfered hole (82) is provided on the outside of the inner oil channel hole (81).

2. The fracture-resistant diesel engine crankshaft according to claim 1, characterized in that: The diameter b of the oil-slinging ring hole (6) is 5 to 9 mm, the ratio of the diameter b of the oil-slinging ring hole (6) to the maximum diameter c of the oil-introducing cone hole (7) is b:c=1:(1.45 to 1.5), and the length d of the oil-introducing cone hole (7) is 0.3 to 0.45 times the length of the right balancing block (4).

3. The fracture-resistant diesel engine crankshaft according to claim 2, characterized in that: The ratio of the diameter b of the oil slinger hole (6) to the maximum diameter c of the oil guide cone hole (7) is b:c=1:1.5, and the length d of the oil guide cone hole (7) is 0.36 times the length D of the right balance block (4).

4. The fracture-resistant diesel engine crankshaft according to claim 1, characterized in that: The axis of the radial lubricating oil hole (8) is located below the horizontal axis of the oil slinger hole (6), and the angle between the axis of the radial lubricating oil hole (8) and the horizontal axis of the oil slinger hole (6) is 0 to 180 degrees.

5. The fracture-resistant diesel engine crankshaft according to claim 4, characterized in that: The angle between the axis of the radial lubricating oil hole (8) and the horizontal axis of the oil slinger hole (6) is 60 to 120 degrees.

6. The fracture-resistant diesel engine crankshaft according to claim 5, characterized in that: The axis of the radial lubricating oil hole (8) is perpendicular to the horizontal axis of the oil slinger hole (6).

7. The fracture-resistant diesel engine crankshaft according to claim 1, characterized in that: The diameter of the left hole of the stepped hole is 2 to 5 mm, and the diameter of the right hole is 1 to 3 mm larger than that of the left hole.

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