Diesel engine connecting rod assembly

Abstract

The diesel engine connecting rod assembly comprises a connecting rod body, a connecting rod cover, a connecting rod stud and a nut, the connecting rod stud and the nut are matched to be used for fixedly connecting the connecting rod body and the connecting rod cover, diagonal planes are arranged on the connecting end face between the connecting rod body and the connecting rod cover, and sawteeth meshed with each other are arranged on the two diagonal planes. The connecting rod stud comprises a middle polish rod and threaded sections located at the two ends of the middle polish rod respectively, and a nest hole is formed in the end, screwed into the connecting rod body, of the connecting rod stud. In the working process, the diagonal planes of the connecting rod body and the connecting rod cover and the connecting rod stud need to bear large shearing force, the sawteeth which are meshed with each other are arranged on the two diagonal planes, the reliability of connection and positioning of the connecting rod body and the connecting rod cover can be improved, and the shearing force to the connecting rod stud can be reduced. The nest holes can disperse stress of the threads on the connecting rod stud, the situation that the front threads of the thread section are broken due to overlarge stress is avoided, the reliability of the connecting rod stud is improved, and the bearing capacity of the diesel engine connecting rod assembly is overall improved.

Description

Technical Field

[0001] The utility model relates to the technical field of engines, in particular to a connecting rod assembly of a diesel engine. Background Art

[0002] The connecting rod assembly of a diesel engine is one of the key components of a diesel engine, which mainly includes the connecting rod body, connecting rod cap, connecting rod stud, bushing and bearing. The function of the connecting rod assembly is to convert the reciprocating motion of the piston into the rotational motion of the crankshaft, and transmit the gas explosion pressure on the piston to the crankshaft. The connecting rod assembly is mainly subjected to periodic alternating mechanical loads, including tensile and compressive fatigue loads (including gas explosion pressure and inertia force), bending loads, and static loads caused by pressing into bushings, pressing bearings, tightening bolts, etc.

[0003] The connecting rod assembly of a diesel engine bears a large load and inertia. Whether the connecting rod assembly is designed reasonably is directly related to the power, reliability, vibration and noise, life and economy of the diesel engine. The main reasons for the failure of the connecting rod in the prior art are:

[0004] (1) The connecting rod studs securely connect the connecting rod cap and the connecting rod body together. However, because the connecting rod assembly is subjected to a large impact load when the diesel engine is operating, the connecting rod studs can easily become loose, resulting in an unreliable connection and the connecting rod body and the connecting rod cap becoming detached.

[0005] (2) The connecting rod journal is prone to cracking or even breaking. The main reason is that the design of the connecting rod cutout is unreasonable and the structural shape of the connecting rod is prone to stress concentration.

[0006] In order to solve the above technical problems, it is necessary to improve the diesel engine connecting rod assembly in the prior art. Utility Model Content

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the utility model is to provide a diesel engine connecting rod assembly, which can ensure the reliability of the connection between the connecting rod body and the connecting rod cover and improve the load-bearing capacity of the diesel engine connecting rod assembly.

[0008] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0009] A connecting rod assembly for a diesel engine comprises a connecting rod body, a connecting rod cover, a connecting rod stud and a nut, wherein the connecting rod stud and the nut cooperate to fix the connecting rod body and the connecting rod cover, and is characterized in that:

[0010] The connecting end surface between the connecting rod body and the connecting rod cover is provided with a chamfered surface, and the two chamfered surfaces are provided with saw teeth that engage with each other.

[0011] The connecting rod stud comprises a middle polished rod and threaded sections respectively located at two ends of the middle polished rod. One end of the connecting rod stud screwed into the connecting rod body is provided with a socket hole.

[0012] Preferably: a piston connecting hole is provided at one end of the connecting rod body, and a bearing mounting hole is provided at the other end of the connecting rod body and the connecting rod cover together, the line connecting the center of the piston connecting hole and the center of the bearing mounting hole is the center line of the connecting rod body, and the angle between the beveled surface of the connecting rod body and the center line is an acute angle.

[0013] Preferably, the angle between the chamfered surface of the connecting rod body and the center line is α, and 35°≤α≤45°.

[0014] Preferably, an inclined oil hole is provided on the connecting rod body.

[0015] Preferably, the angle between the oil hole and the center line is β, 5°≤β≤20°.

[0016] Preferably, the thread on the thread segment is a fine pitch thread.

[0017] Preferably, the socket includes a straight hole section, a tapered hole section and a spherical end in sequence from the opening to the end, and the straight hole section and the tapered hole section have an arc transition at their intersection.

[0018] Preferably, the connecting rod body comprises a small end connecting portion, a main body and a large end connecting portion, the small end connecting portion is provided with the piston connecting hole, the large end connecting portion is provided with a bearing bushing mounting hole, and the main body is configured as a cylinder.

[0019] Preferably, a bushing is installed in the piston connecting hole of the connecting rod body, and an upper connecting rod bearing and a lower connecting rod bearing are fixed at the bearing installation hole.

[0020] After adopting the above technical solution, the beneficial effects of the utility model are:

[0021] The diesel engine connecting rod assembly of the utility model has a chamfered surface on the connecting end surface between the connecting rod body and the connecting rod cover. During operation, the chamfered surfaces of the connecting rod body and the connecting rod cover and the connecting rod stud are subjected to a large shear force. The two chamfered surfaces are provided with saw teeth that mesh with each other, which can improve the reliability of the connection and positioning of the connecting rod body and the connecting rod cover and reduce the shear force on the connecting rod stud. The smaller the angle between the chamfered surface of the connecting rod body and the center line, the smaller the lateral width of the big end of the connecting rod. Under the condition that the connecting rod body can pass through the cylinder, the main body of the connecting rod body can be thickened to the maximum extent, thereby increasing the strength of the connecting rod body and meeting the requirements of disassembling and assembling the connecting rod from the cylinder.

[0022] The connecting rod stud includes a middle polished rod and threaded sections at both ends of the middle polished rod. A socket is provided at one end of the connecting rod stud that is screwed into the connecting rod body. The socket can disperse the force on the thread of the connecting rod stud, avoiding the force on the thread teeth of the thread section being concentrated on the first few buckles, causing the first few buckles to break due to excessive force, which can improve the reliability of the connecting rod bolt in all directions, thereby preventing the bolt from loosening.

[0023] In summary, the diesel engine connecting rod assembly of the utility model improves the reliability of the connection between the connecting rod body and the connecting rod cover, improves the load-bearing capacity of the diesel engine connecting rod assembly, and extends the service life by optimizing the design of the connecting end surface between the connecting rod body and the connecting rod cover and the structure of the connecting piece (connecting rod stud). BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a diesel engine connecting rod assembly of the utility model;

[0025] Figure 2 yes Figure 1 Schematic diagram of the exploded structure of the connecting rod assembly of a diesel engine;

[0026] Figure 3 yes Figure 1 Schematic diagram of the structure of the middle connecting rod stud;

[0027] In the figure:

[0028] 1. Connecting rod body; 1a. Small end connection; 1b. Main body; 1c. Large end connection; 101. Piston connection hole; 102. Bearing installation hole; 103. Oil hole; 2. Connecting rod cap; 3. Connecting rod stud; 31. Middle polished rod; 32. Threaded section; 33. Socket; 331. Straight hole section; 332. Tapered hole section; 333. Spherical end; 4. Nut; 5. Bushing; 6. Connecting rod upper bearing; 7. Connecting rod lower bearing. DETAILED DESCRIPTION

[0029] The technical solution of the utility model is described in detail below in conjunction with the accompanying drawings and specific embodiments to further understand the purpose, solution and effect of the utility model, but it is not intended to limit the scope of protection of the claims attached to the utility model.

[0030] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0031] In addition, although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0032] The utility model discloses some embodiments, such as Figure 1 and Figure 2 As shown, the diesel engine connecting rod assembly includes a connecting rod body 1, a connecting rod cover 2, a connecting rod stud 3 and a nut 4. The connecting rod stud 3 and the nut 4 are used to fix the connecting rod body 1 and the connecting rod cover 2.

[0033] The connecting end surface between the connecting rod body 1 and the connecting rod cover 2 is provided with a chamfered surface, and the two chamfered surfaces are provided with saw teeth that mesh with each other.

[0034] Since the joint surface between the connecting rod body 1 and the connecting rod cover 2 is a beveled surface, during the working process, the beveled surfaces of the connecting rod body 1 and the connecting rod cover 2 and the connecting rod stud 3 are subject to greater shear force. The two beveled surfaces are provided with mutually interlocking serrations that can withstand greater shear force, thereby improving the reliability of the connection and positioning between the connecting rod body 1 and the connecting rod cover 2, and reducing the radial shear stress of the connecting rod stud 3, thereby avoiding deformation of the connecting rod stud 3 due to shear stress, which in turn leads to wear of the connecting rod bearing.

[0035] like Figure 3 As shown, the connecting rod stud 3 includes a middle polished rod 31 and threaded sections 32 respectively located at both ends of the middle polished rod, and a socket 33 is provided at one end of the connecting rod stud 3 that is screwed into the connecting rod body 1. The socket 33 provided at one end of the connecting rod stud 3 can disperse the force on the thread on the connecting rod stud 3, avoiding the force on the thread teeth of the threaded section 32 being concentrated on the first few buckles, causing the first few buckles to break due to excessive force, and can comprehensively improve the reliability of the connecting rod bolt, thereby realizing the anti-loosening of the bolt.

[0036] In some embodiments, the thread on the thread segment is a fine-pitch thread. Compared with coarse-pitch threads, fine-pitch threads have a smaller pitch, a smaller helix angle of the thread, a gentler angle of thread landslide, and are more conducive to self-locking of the thread. The anti-loosening effect is further improved. The connecting rod stud 3 is assembled by stretching with a hydraulic tensioner, and the hydraulic stretching force acts directly on the connecting rod stud 3, which can ensure that the axial force on the connecting rod stud 3 reaches the design value. In the prior art, the connecting rod body 1 and the connecting rod cover 2 are usually tightened with hexagonal head bolts. The axial force on the hexagonal head bolts is affected by factors such as the friction coefficient, tightening requirements, and installation methods. The discreteness is large, and the reliability of anti-loosening is low. It cannot be compared with the connecting rod stud 3 of the utility model assembled with a hydraulic tensioner.

[0037] In some embodiments, a piston connecting hole 101 is formed at one end of the connecting rod body 1, and a bearing mounting hole 102 is formed at the other end of the connecting rod body 1 and the connecting rod cover 2. The line connecting the center of the piston connecting hole 101 and the center of the bearing mounting hole 102 is the center line of the connecting rod body 1, and the angle between the beveled surface of the connecting rod body 1 and the center line is an acute angle.

[0038] In some embodiments, it is preferred to set the angle between the chamfered surface of the connecting rod body 1 and the center line to be α, 35°≤α≤45°. The smaller the angle α between the chamfered surface of the connecting rod body 1 and the center line, the smaller the lateral width of the big end of the connecting rod, and the larger the value of the allowable increase in the diameter of the main body of the connecting rod body under the condition that the connecting rod body 1 can pass through the cylinder, that is, the main body of the connecting rod body can be thickened to the maximum extent, thereby increasing the strength of the connecting rod body, so that the diesel engine connecting rod assembly has a strong load-bearing capacity, extends the service life, and can meet the requirements of disassembling and assembling the connecting rod from the cylinder.

[0039] In some embodiments, the connecting rod body 1 includes a small head connecting portion 1a, a main body 1b and a large head connecting portion 1c. The small head connecting portion 1a has the piston connecting hole 101, the large head connecting portion 1c has the bearing mounting hole 102, and the main body 1b is configured as a cylinder, thereby eliminating the problem of stress concentration on the connecting rod body 1b (non-processed part) due to surface defects of the blank.

[0040] The main body of the traditional forged I-shaped connecting rod is greatly affected by the forging process technology level or human and environmental factors, and the surface quality consistency of the main body of the connecting rod is difficult to control. Processing the main body of the connecting rod into a cylinder eliminates the risk of stress concentration on the rod body caused by forging defects.

[0041] In some embodiments, a bushing 5 is installed in the piston connecting hole 101 of the connecting rod body 1, and an upper connecting rod bearing 6 and a lower connecting rod bearing 7 are fixed to the bearing installation hole 102.

[0042] In some embodiments, an inclined oil hole 103 is provided on the connecting rod body 1. Assume that the angle between the oil hole 103 and the center line is β, 5°≤β≤20°. The main load-bearing area of ​​the bearing shell mounting hole 102 of the connecting rod body 1 is near the center line of the connecting rod body 1. The opening of the oil hole 103 avoids the main load-bearing area of ​​the bearing shell mounting hole 102 of the connecting rod body 1 to ensure that the bearing shell of the connecting rod body is normally stressed.

[0043] In some embodiments, the socket 33 includes a straight hole section 331 , a tapered hole section 332 and a spherical end 333 in sequence from the opening to the end, and the straight hole section 331 and the tapered hole section 332 have an arc transition at their intersection.

[0044] In summary, the diesel engine connecting rod assembly of the utility model improves the reliability of the connection between the connecting rod body and the connecting rod cover by optimizing the design of the connecting end surface between the connecting rod body and the connecting rod cover and the structure of the connecting piece (connecting rod stud), so that the diesel engine connecting rod assembly has a strong load-bearing capacity and extends its service life.

[0045] The present invention is not limited to the above embodiments, and all improvements made based on the concept, principle, structure and method of the present invention are within the protection scope of the present invention.

Claims

1. A connecting rod assembly for a diesel engine, comprising a connecting rod body, a connecting rod cover, a connecting rod stud and a nut, wherein the connecting rod stud and the nut cooperate to fix the connecting rod body and the connecting rod cover, characterized in that: The connecting end surface between the connecting rod body and the connecting rod cover is provided with a chamfered surface, and the two chamfered surfaces are provided with saw teeth that engage with each other. The connecting rod stud comprises a middle polished rod and threaded sections respectively located at two ends of the middle polished rod. One end of the connecting rod stud screwed into the connecting rod body is provided with a socket hole.

2. The diesel engine connecting rod assembly according to claim 1, characterized in that: A piston connecting hole is provided at one end of the connecting rod body, and a bearing mounting hole is provided at the other end of the connecting rod body and the connecting rod cover. The line connecting the center of the piston connecting hole and the center of the bearing mounting hole is the center line of the connecting rod body, and the angle between the beveled surface of the connecting rod body and the center line is an acute angle.

3. The diesel engine connecting rod assembly according to claim 2, characterized in that: Assume that the angle between the chamfered surface of the connecting rod body and the center line is α, 35°≤α≤45°.

4. The diesel engine connecting rod assembly according to claim 2, characterized in that: An inclined oil hole is provided on the connecting rod body.

5. The diesel engine connecting rod assembly according to claim 4, characterized in that: Assume that the angle between the oil hole and the center line is β, 5°≤β≤20°.

6. The diesel engine connecting rod assembly according to claim 1, characterized in that: The threads on the threaded sections are fine pitch threads.

7. The diesel engine connecting rod assembly according to claim 1, characterized in that: The socket hole comprises a straight hole section, a tapered hole section and a spherical end in sequence from the opening to the end, and the straight hole section and the tapered hole section have an arc transition at their intersection.

8. The diesel engine connecting rod assembly according to claim 2, characterized in that: The connecting rod body comprises a small end connecting part, a main body and a large end connecting part, the small end connecting part is provided with the piston connecting hole, the large end connecting part is provided with a bearing bushing mounting hole, and the main body is configured as a cylinder.

9. The diesel engine connecting rod assembly according to claim 2, characterized in that: A bushing is installed in the piston connecting hole of the connecting rod body, and an upper connecting rod bearing bush and a lower connecting rod bearing bush are fixed at the bearing bush installation hole.

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