Piston connecting rod assembly

Abstract

The utility model discloses a piston connecting rod assembly, which belongs to the technical field of engines and comprises a piston and a connecting rod, a piston pin is arranged on the piston, a connecting rod bushing rotationally sleeved with the piston pin is arranged at the end of the connecting rod, and two piston main oil holes are formed in diagonal angles of the front end of a main pusher and the rear end of an auxiliary pusher on the inner side of the piston; and two piston pair oil return holes are formed in the inner side of the piston on the normal plane of the axis of the piston pin. During oil return, the connecting rod small end is lubricated through the main oil return hole, and the piston pin is directly lubricated through the two piston auxiliary oil return holes, so that good lubrication of the connecting rod small end and the piston pin is effectively considered, and a pin hole meshing fault is avoided. The structure is simple and practicability is good.

Description

Technical Field

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

[0002] An internal combustion engine is a heat engine that converts the chemical energy of fuel into mechanical energy. Its operating principle is based primarily on the combustion process and the principles of thermodynamics. Internal combustion engines are generally classified into two types: piston and rotary, with piston engines being the most common type.

[0003] The piston engine is a common internal combustion engine, widely used in automobiles, aircraft, tractors, and generators. Its operating principle is based on a four-stroke cycle, consisting of intake, compression, expansion, and exhaust. During the intake stroke, the piston moves from top dead center to bottom dead center, and the intake valve opens, allowing the air-fuel mixture to enter the cylinder. Then, during the compression stroke, the piston returns to top dead center, compressing the air-fuel mixture in preparation for combustion. At the end of the compression stroke, the ignition system ignites the air-fuel mixture, generating high-temperature, high-pressure gas that pushes the piston downward, completing the expansion stroke. Finally, during the exhaust stroke, the piston moves upward again, and the exhaust valve opens, expelling the exhaust gases from the cylinder.

[0004] Currently, most diesel engines feature piston oil inlet and return ports that are diagonally spaced at the front of the primary thrust and rear of the secondary thrust. This design, in the absence of forced lubrication ports for the connecting rod in some medium-displacement diesel engines, fails to provide lubrication for both the small end of the connecting rod and the piston pin. Diesel engine optimization and development have been accompanied by a continuous increase in in-cylinder explosion pressure, with the maximum explosion pressure having been upgraded from 16MPa to 20-24MPa. This increase in explosion pressure inevitably leads to increased surface pressure and operating temperature in the pin-hole mating area. Under certain operating conditions, abnormal temperatures and lack of lubrication can cause pin-hole seizure failure, which, once occurring, can easily cause engine cylinder scuffing, resulting in significant impact. Utility Model Content

[0005] In order to solve the problem that a conventional diesel engine cannot provide lubrication for both the connecting rod small end and the piston pin, which easily causes a pin hole bite failure, the utility model provides a piston connecting rod assembly.

[0006] The utility model is realized through the following technical solutions:

[0007] A piston-connecting rod assembly comprises a piston and a connecting rod, wherein a piston pin is provided on the piston, a connecting rod bushing is provided at the end of the connecting rod and is rotatably fitted with the piston pin, two main piston oil holes are provided at diagonally opposite angles at the main thrust front end and the auxiliary thrust rear end on the inner side of the piston; two auxiliary piston oil return holes are provided on the inner side of the piston on the normal plane of the piston pin axis.

[0008] A further improvement of the present invention is that the two piston pair oil return holes are symmetrically arranged.

[0009] A further improvement of the present invention is that the angle between the axis of the piston auxiliary oil return hole and the center axis of the piston is α, and α is ≥50°.

[0010] A further improvement of the present invention is that the auxiliary oil return hole of the piston is in a tapered hole shape that gradually contracts along the oil return direction.

[0011] A further improvement of the present invention is that the taper angle β of the piston auxiliary oil return hole is 5°≤β≤15°.

[0012] A further improvement of the present invention is that the diameter of the main oil hole of the piston is Φ1, the maximum diameter of the auxiliary oil return hole of the piston is Φ2, and Φ2<Φ1.

[0013] A further improvement of the present invention is that the piston diameter is D, the compression height is H, and H≤0.55D.

[0014] A further improvement of the present invention is that the vertical distance between the piston auxiliary oil return hole and the piston center axis is S, and S≤0.3D.

[0015] A further improvement of the present invention is that the end of the connecting rod close to the piston is elliptical in the circumferential direction, with the shortest diameter being dn, the longest diameter being d, d0= / 2, and d0≤5mm.

[0016] A further improvement of the present invention is that the connecting rod bushing is made of copper alloy and the surface of the piston pin is coated with a diamond-like coating.

[0017] It can be seen from the above technical solutions that the beneficial effects of the present invention are:

[0018] A main oil return hole is located at the front end of the main thruster, and a main oil inlet hole is located at the rear end of the auxiliary thruster. The main oil return hole and the main oil inlet hole are arranged diagonally. Two auxiliary oil return holes are located on the normal plane of the piston pin axis. During oil return, the main oil return hole lubricates the connecting rod small end, and the two auxiliary oil return holes directly lubricate the piston pin, effectively ensuring good lubrication of the connecting rod small end and the piston pin, avoiding pin hole seizure failure. The structure is simple and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for the description. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a structural diagram of a specific implementation method of the utility model.

[0021] Figure 2This is a schematic diagram of the piston auxiliary oil return hole in a specific embodiment of the present utility model.

[0022] Figure 3 This is a schematic diagram of the arrangement of the piston main oil hole and the piston auxiliary oil return hole in a specific embodiment of the present utility model.

[0023] Figure 4 This is a schematic diagram of the circumferential profile of the connecting rod head according to a specific embodiment of the present invention.

[0024] In the attached figure: 1. piston, 2. connecting rod, 3. piston pin, 4. connecting rod bushing, 5. piston auxiliary oil return hole, 6. piston main oil hole. DETAILED DESCRIPTION

[0025] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the specific embodiments. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this patent.

[0026] like Figure 1-4 As shown, the utility model discloses a piston-connecting rod assembly, comprising a piston 1 and a connecting rod 2. The piston 1 is provided with a piston pin 3. The end of the connecting rod 2 is provided with a connecting rod bushing 4 that is rotatably fitted around the piston pin 3. Two main piston oil holes 6 are provided diagonally on the inside of the piston 1, at the main thrust front end and the secondary thrust rear end. Two secondary piston oil return holes 5 are provided on the inside of the piston 1, on the plane normal to the axis of the piston pin 3. Both the main piston oil holes 6 and the secondary piston oil return holes 5 are connected to the oil passage inside the piston 1.

[0027] A main oil return hole is located at the front end of the main thruster, and a main oil inlet hole is located at the rear end of the auxiliary thruster. The main oil return hole and the main oil inlet hole are arranged diagonally. Two auxiliary piston oil return holes 5 are provided on the plane normal to the axis of the piston pin 3. During oil return, the main oil return hole lubricates the small end of the connecting rod 2 (the end closest to the piston 1), while the two auxiliary piston oil return holes 5 directly lubricate the piston pin 3. This effectively ensures good lubrication of both the small end of the connecting rod 2 and the piston pin 3, avoiding pin-hole seizure failure. The structure is simple and practical.

[0028] Among them, such as Figure 1 、 3 As shown, the two piston pair oil return holes 5 are symmetrically arranged to ensure balanced lubrication of the piston pin 3.

[0029] Further, such as Figure 1 、 3As shown, the piston 1 has a diameter of D and a compression height of H, where H is ≤ 0.55D. The vertical distance between the piston auxiliary oil return hole 5 and the center axis of the piston 1 is S, where S is ≤ 0.3D. This ensures good lubrication of the piston pin 3.

[0030] The included angle between the axis of the piston auxiliary oil return hole 5 and the center axis of the piston 1 is α, α≥50°. When the small end of the connecting rod 2 rotates, the piston pin 3 is fully lubricated.

[0031] Among them, such as Figure 2 As shown, the piston auxiliary oil return hole 5 is in a tapered shape along the oil return direction, which effectively increases the flow rate of the return oil beam and improves the lubrication effect.

[0032] Furthermore, the taper angle of the piston auxiliary oil return hole is β, 5°≤β≤15°. While ensuring smooth oil return, the return oil flow rate is increased.

[0033] The diameter of the piston main oil hole 6 is Φ1, and the maximum diameter of the piston auxiliary oil return hole 5 is Φ2, where Φ2 is less than Φ1. The influence on the oil flow velocity of the main oil return hole is minimized.

[0034] The end of the connecting rod 2 closest to the piston 1 is elliptical in shape, with a minimum diameter of dn and a maximum diameter of d, where d0 = (d-dn) / 2, and d0 ≤ 5mm. This effectively speeds up the oil film buildup during the initial run-in period.

[0035] The connecting rod bushing 4 is made of copper alloy, and the piston pin 3 is coated with a self-lubricating diamond-like coating. This effectively improves the bearing capacity of the connecting rod bushing 4, enhances the wear resistance and anti-seizure properties of the piston pin 3, and reduces the probability of pin seizure.

[0036] This piston-connecting rod assembly features a primary oil return hole at the front end of the main thrust and a primary oil inlet hole at the rear end of the secondary thrust. The primary and secondary oil return holes are diagonally arranged, and two secondary piston oil return holes 5 are provided on the plane normal to the axis of the piston pin 3. During oil return, the primary oil return hole lubricates the small end of the connecting rod 2, while the two secondary piston oil return holes 5 directly lubricate the piston pin 3. This effectively ensures good lubrication of both the small end of the connecting rod 2 and the piston pin 3, preventing pin-hole seizure. This provides a simple structure and excellent practicality.

[0037] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0038] The terms "upper," "lower," "outer," "inner," and the like, if used in the specification and claims of the present invention and the accompanying drawings, are used to distinguish relative positions and do not necessarily define them. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be implemented in sequences other than those illustrated or described herein. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0039] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A piston-connecting rod assembly, characterized in that: The invention comprises a piston (1) and a connecting rod (2), wherein a piston pin (3) is provided on the piston (1), a connecting rod bushing (4) which is rotatably fitted with the piston pin (3) is provided at the end of the connecting rod (2), two piston main oil holes (6) are provided at diagonally opposite angles at the main thrust front end and the auxiliary thrust rear end on the inner side of the piston (1); and two piston auxiliary oil return holes (5) are provided on the inner side of the piston (1) on the normal plane of the piston pin (3) axis.

2. The piston-connecting rod assembly according to claim 1, characterized in that: The two piston pair oil return holes (5) are symmetrically arranged.

3. The piston-connecting rod assembly according to claim 2, wherein: The included angle between the axis of the piston auxiliary oil return hole (5) and the center axis of the piston (1) is α, and α is ≥ 50°.

4. The piston-connecting rod assembly according to claim 1, wherein: The piston auxiliary oil return hole (5) is in a tapered shape that gradually contracts along the oil return direction.

5. The piston-connecting rod assembly according to claim 4, characterized in that: The taper angle of the piston auxiliary oil return hole (5) is β, 5°≤β≤15°.

6. The piston-connecting rod assembly according to claim 4, characterized in that: The diameter of the piston main oil hole (6) is Φ1, and the maximum diameter of the piston auxiliary oil return hole (5) is Φ2, Φ2<Φ1.

7. The piston-connecting rod assembly according to claim 2, wherein: The diameter of the piston (1) is D, and the compression height is H, where H≤0.55D.

8. The piston-connecting rod assembly according to claim 7, wherein: The vertical distance between the piston auxiliary oil return hole (5) and the center axis of the piston (1) is S, S≤0.3D.

9. The piston-connecting rod assembly according to claim 1, wherein: The end of the connecting rod (2) close to the piston (1) is elliptical in the circumferential direction, with a shortest diameter of dn and a longest diameter of d, d0=(d-dn) / 2, and d0≤5mm.

10. The piston-connecting rod assembly according to claim 1, wherein: The connecting rod bushing (4) is made of copper alloy, and the surface of the piston pin (3) is coated with a diamond-like coating.

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