Piston oil return structure

Abstract

The utility model discloses a piston oil return structure, including a plurality of long strip structure's oil return groove, oil return groove sets up on the piston pin seat, and one end of oil return groove communicates with cooling oil cavity, and the other end of oil return groove communicates with the gap between pin seat and connecting rod small head. The utility model provides a piston oil return structure can effectively solve the piston pin hole and connecting rod small head hole lubrication bad cause piston pin and connecting rod small head, piston pin hole occlusion problem, improve piston pin hole kinematic pair's reliability.

Description

Technical Field

[0001] This utility model relates to the field of piston technology, and in particular to a piston oil return structure. Background Technology

[0002] Most existing metal pistons (such as steel pistons) employ an offset, angled oil return hole design. This angled oil hole is positioned parallel to the clearance between the piston pin and the small end of the connecting rod. Cooling oil in the cooling oil chamber flows out through the angled oil return hole, passes through the clearance between the pin and the connecting rod, enters the upper end of the piston pin, and finally enters the piston pin bore and the connecting rod small end bore, achieving lubrication. However, the existing angled oil holes on steel pistons are machined by drilling. This requires a guide recess structure at the drilled area, which affects mold life and causes quality issues such as difficulty in forging thinner areas, impacting piston reliability. Furthermore, this existing design, with the angled oil hole parallel to the clearance between the connecting rod small end and the pin, results in a relatively small flow rate of cooling oil, limiting lubrication and cooling effects. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a piston oil return structure, which can effectively solve the problem of piston pin seizing with connecting rod small end and piston pin hole due to poor lubrication of steel piston pin hole and connecting rod small end hole, and improve the reliability of piston pin hole moving pair.

[0004] The technical solution provided by this utility model is as follows: A piston oil return structure includes several elongated oil return grooves, which are disposed on the piston pin seat. One end of the oil return groove is connected to the cooling oil chamber, and the other end of the oil return groove is connected to the gap between the pin seat and the small end of the connecting rod.

[0005] Preferably, the number of oil return grooves is one, and the oil return groove has a rectangular structure.

[0006] Preferably, the length L of the oil return groove is 30% to 60%∅K, where ∅K is the diameter of the pin hole.

[0007] Preferably, the width H of the oil return groove is 3% to 5%∅K, where ∅K is the diameter of the pin hole.

[0008] Preferably, the height M of the oil return groove from the pin hole axis is M = ∅K / 2 + N mm, where ∅K is the diameter of the pin hole, N is the distance from the upper side of the pin hole to the oil return groove, and N ≥ 3 mm. If the pin seat structure allows, N should be as large as possible to reduce the impact on the strength of the pin seat structure.

[0009] Preferably, the oil return groove is inclined inside the piston.

[0010] Preferably, the angle between the oil return groove and the horizontal direction is X, where X ≥ 15°.

[0011] Preferably, the oil return groove is set at a certain angle to the piston pin seat.

[0012] Preferably, the included angle between the oil return groove and the piston pin seat is 30 to 75°.

[0013] Preferably, the number of oil return grooves is two or more, and the oil return grooves are rectangular or elongated structures. Several oil return grooves are not continuous but are arranged parallel to each other in the same direction.

[0014] This invention has the following advantages over the prior art: The piston oil return structure of this utility model, through the setting of the long strip-shaped oil return groove, allows the cooling lubricating oil to fully enter the gap between the pin seat and the small end of the connecting rod from the oil chamber in a waterfall-like manner, so as to lubricate and cool the piston pin hole, the small end of the connecting rod and the piston pin, improve the reliability of the moving pair and reduce the risk of seizure. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a cross-sectional view of the piston with a piston oil return structure in Embodiment 1 of this utility model; Figure 2 for Figure 1 Sectional view of AA; Figure 3 This is a cross-sectional view of the piston with a piston oil return structure in Embodiment 2 of this utility model.

[0017] Figure label: 1. Oil return groove; 2. Piston pin seat; 3. Cooling oil chamber; 4. Connecting rod small end; 5. Pin hole. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] Example 1: like Figure 1 ,2 As shown, this utility model embodiment provides a piston oil return structure, including an elongated oil return groove 1. The oil return groove 1 is disposed on the piston pin seat 2. One end of the oil return groove 1 is connected to the cooling oil chamber 3, and the other end of the oil return groove 1 is connected to the gap between the pin seat 2 and the small end 4 of the connecting rod. The oil return groove 1 is machined from the skirt oil chamber before the piston is welded.

[0020] In this embodiment, the elongated structure of the oil return groove 1 eliminates the forged inclined oil hole pit structure in the prior art, allowing the oil return to enter the gap between the piston pin seat 2 and the connecting rod small end 4 in a waterfall-like pattern. This provides a better lubrication and cooling environment for the friction between the piston pin hole 5, the connecting rod small end hole, and the piston pin, effectively reducing the risk of steel piston pin hole seizure and improving the quality and reliability of the piston connecting rod assembly.

[0021] In this embodiment, there is one oil return groove, which is rectangular. The length L of the oil return groove 1 is 30% to 60%∅K, the width H is 3% to 5%∅K, and the height M of the oil return groove 1 from the pin hole axis is ∅K / 2 + N mm, where ∅K is the diameter of the pin hole, N is the distance from the top of the pin hole to the oil return groove, and N ≥ 3 mm. Within the limits of the pin seat structure, N should be as large as possible to minimize the impact on the strength of the pin seat structure. The above settings are to maximize the oil return flow and improve the lubrication effect while ensuring the strength of the pin seat structure.

[0022] In this embodiment, the oil return groove 1 is inclined inside the piston, and the angle between the oil return groove 1 and the horizontal direction is X, where X ≥ 15°. The inclined design allows the oil in the oil chamber to flow out better and more fully.

[0023] In this embodiment, the oil return groove 1 and the piston pin seat 2 are set at a 60° angle, which is more conducive to the cooling lubricating oil entering the gap between the piston pin seat 2 and the small end 4 of the connecting rod.

[0024] Example 2: The difference between this embodiment and Embodiment 1 is that: there are three oil return grooves 1. The oil return grooves 1 are rectangular or elongated structures. The three oil return grooves 1 are not continuous but are arranged parallel to each other in the same direction. The total length of the three oil return grooves 1 is equal to 30% to 60%∅K. The maximum width of the oil return groove 1 is H=3% to 5%∅K. The height of the oil return groove 1 from the pin hole axis is M=∅K / 2+Nmm, where ∅K is the diameter of the pin hole, N is the distance from the top of the pin hole to the oil return groove, and N≥3mm. The rest of the structure is the same as in Embodiment 1.

[0025] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those 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 to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A piston oil return structure characterized by, It includes several elongated oil return grooves, which are set on the piston pin seat. One end of the oil return groove is connected to the cooling oil chamber, and the other end of the oil return groove is connected to the gap between the pin seat and the small end of the connecting rod.

2. The piston oil return structure of claim 1, wherein The number of oil return grooves is one, and the oil return groove has a rectangular structure.

3. The piston oil return structure of claim 2, wherein The length L of the oil return groove is 30% to 60%∅K, where ∅K is the diameter of the pin hole.

4. The piston oil return structure of claim 2, wherein The width H of the oil return groove is 3% to 5%∅K, where ∅K is the diameter of the pin hole.

5. The piston oil return structure of claim 2, wherein The height M of the return oil groove from the axis of the pin hole is M = ∅K / 2 + N mm, where ∅K is the diameter of the pin hole, N is the distance from the top of the pin hole to the return oil groove, and N ≥ 3 mm.

6. The piston oil return structure according to any one of claims 1 to 5, characterized by, The oil return groove is inclined inside the piston.

7. The piston oil return structure of claim 6, wherein The angle between the oil return groove and the horizontal direction is X, where X ≥ 15°.

8. The piston oil return structure according to any one of claims 1 to 5, characterized by, The oil return groove is set at a certain angle to the piston pin seat.

9. The piston oil return structure of claim 8, wherein The included angle between the oil return groove and the piston pin seat is 30-75°.

10. The piston oil return structure of claim 1, wherein The number of oil return grooves is two or more, and the oil return grooves are rectangular or elongated structures. Several oil return grooves are not continuous but are arranged parallel to each other in the same direction.

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