Double-oil-belt piston oil ring

Abstract

The utility model discloses a double-oil-belt piston oil ring which is composed of an oil ring body and a spiral spring, and the spiral spring is arranged in an inner circular groove of the oil ring body. The outer circle face of the oil ring body is composed of an upper oil scraping belt and a lower oil scraping belt. The outer circle outline of the cross section of each of the upper oil scraping belt and the lower oil scraping belt comprises a conical surface part and a cylindrical surface part, and the sum of the axial heights of the two parts is the width of the oil belt; the width of the upper oil scraping belt is twice or more than that of the lower oil scraping belt; the cylindrical surface part of the upper oil scraping belt is arranged on one side close to the outer circular groove; the cylindrical surface part of the lower oil scraping belt is arranged on one side close to the outer lower chamfer; the included angle between the conical surface part and the cylindrical surface part of the upper oil scraping belt is 1-5 degrees, and the included angle between the conical surface part and the cylindrical surface part of the lower oil scraping belt is 10-30 degrees. According to the utility model, the effect of reducing upward oil scraping is fully considered, and the thickness of an oil film remained on the surface of the cylinder during ascending is increased, so that the oil consumption rate, friction and reliability are facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of piston rings, in particular to a double-oil-belt piston oil ring. Background Art

[0002] The power cylinder unit of an internal combustion engine consists of a cylinder, piston, piston rings, piston pin, and other moving parts. These moving parts are lubricated by oil splashing and / or spraying onto the inner wall of the cylinder to achieve optimal operation. In a four-stroke internal combustion engine, piston rings, particularly the oil ring, play a crucial role in preventing excessive oil from remaining on the inner wall of the cylinder during each stroke and being transported to the combustion chamber at the top of the piston and burned. As the piston moves up and down within the cylinder, the oil ring's outer circumferential scraper removes excess oil and distributes a film of oil within the cylinder, providing lubrication for the friction pair.

[0003] As a standardized component, the ISO / GB standard has some general requirements for oil rings. Essentially, they feature two oil-scraping strips on their outer surface, a spring force that allows them to adhere tightly to the cylinder wall, primarily from an internal coil spring. They also have an oil return hole that connects the oil to the inside and outside of the ring, allowing scraped oil to flow back into the engine's oil pan. Clearly, achieving better oil-scraping capacity (i.e., lower oil consumption) while also achieving lower frictional power consumption (i.e., lower fuel consumption) and maintaining good reliability and durability are the constant pursuits of engineers in this field.

[0004] Regarding the external oil scraper, in addition to conventional cylindrical oil scrapers, stepped, conical, and arc-shaped structures are now available and widely used. Essentially, these structures reduce the actual contact width between the scraper and the cylinder, enabling higher contact pressures with lower spring forces, thereby reducing oil consumption to a certain extent. However, practice has shown that, as the current oil ring moves upward with the piston, it still has a strong upward scraping effect, resulting in minimal oil remaining on the cylinder surface. This is detrimental to friction pair lubrication. Furthermore, the oil scraped toward the combustion chamber increases carbon deposits, leading to increased carbon deposits on the ring surface and within the ring grooves. This poses a risk of piston ring seizure and failure within the grooves, hindering further reductions in oil consumption. Summary of the Invention

[0005] Purpose of the utility model: In order to overcome the shortcomings of the background technology, the utility model seeks to protect a double-oil-belt piston oil ring.

[0006] Technical solution: The double-oil-belt piston oil ring disclosed in the utility model is composed of an oil ring body and a coil spring, and the coil spring is installed in the inner circular groove of the oil ring body;

[0007] The outer circumferential surface of the oil ring body is composed of an upper oil scraping belt and a lower oil scraping belt;

[0008] An outer upper chamfer is provided at the junction of the upper oil scraping belt and the upper end surface of the oil ring body, and an outer lower chamfer is provided at the junction of the lower oil scraping belt and the lower end surface of the oil ring body. An outer circular groove is formed between the upper and lower oil scraping belts, and the outer circular groove is connected to the upper and lower oil scraping belts through the outer groove bevel.

[0009] An oil return hole is provided at the center of the outer circular groove;

[0010] The cross-sectional outer contours of the upper and lower oil scraping strips each include a conical portion and a cylindrical portion, and the sum of the axial heights of the two portions is the width of the oil strip;

[0011] The width of the upper oil scraping belt is twice or more than the width of the lower oil scraping belt;

[0012] The cylindrical portion of the upper oil scraping belt is arranged on a side close to the outer circular groove; the cylindrical portion of the lower oil scraping belt is arranged on a side close to the outer lower chamfer;

[0013] The angle between the conical part and the cylindrical part of the upper oil scraping belt is 1-5 degrees, and the angle between the conical part and the cylindrical part of the lower oil scraping belt is 10-30 degrees;

[0014] The upper oil scraping belt is arranged toward the combustion chamber of the piston.

[0015] Furthermore, the outer upper chamfer and the outer lower chamfer form an angle of 20-45° with the end face.

[0016] Furthermore, the outer groove oblique angles are symmetrically distributed above and below the central horizontal line of the oil return hole, and the included angle is 5-40°.

[0017] Furthermore, the cross-sectional profile of the inner circular groove is an axisymmetric structure with the horizontal center line of the oil ring body as the axis of symmetry.

[0018] Furthermore, the width of the upper oil scraping belt is 0.6-1.1 mm, the width of the lower oil scraping belt is 0.18-0.37 mm, the axial height of the cylindrical part of the upper oil scraping belt is 0.03-0.2 mm, and the axial height of the cylindrical part of the lower oil scraping belt is 0.03-0.17 mm.

[0019] Furthermore, the lower edges of the upper and lower oil scraping belts are both provided with sharp rounded corners, and the arc radius is R0.005-0.2mm.

[0020] Furthermore, the radial offset of the highest point of the outer circumferential surface of the upper oil scraping belt and the lower oil scraping belt is less than 0.01 mm.

[0021] Beneficial effects: Compared with the prior art, the advantages of the present invention are: the upper oil scraping belt and the lower oil scraping belt of the present invention have different widths and tapers, and the oil return hole is biased below the center line of the ring height, which fully considers the effect of reducing the upward oil scraping and increasing the thickness of the oil film retained on the cylinder surface during upward movement, thereby being beneficial to the oil consumption rate, friction and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the overall main view of the utility model;

[0023] Figure 2 This is a radial cross-sectional view of the utility model;

[0024] Figure 3 This is the oil scraping cloth effect diagram of the utility model. DETAILED DESCRIPTION

[0025] like Figure 1 The double-oil-belt piston oil ring shown is composed of an oil ring body 1 and a coil spring 2. The coil spring 2 is installed in the inner circular groove of the oil ring body 1 to increase the elastic force of the oil ring.

[0026] The base material of the oil ring body 1 is one of gray cast iron, alloy cast iron, ductile iron and steel.

[0027] like Figure 2 As shown, the oil ring body includes an upper end face, a lower end face, an outer circle, an inner circle, an outer groove, an inner groove and an oil return hole.

[0028] The outer circumferential surface of the oil ring body 1 is composed of an upper oil scraping belt 101 and a lower oil scraping belt 102 .

[0029] An outer upper chamfer 103 is provided at the place where the upper oil scraping belt 101 connects with the upper end surface S1 of the oil ring body 1, and an outer lower chamfer 104 is provided at the place where the lower oil scraping belt 102 connects with the lower end surface S2 of the oil ring body 1. An outer circular groove 105 is formed between the upper oil scraping belt 101 and the lower oil scraping belt 102, and the outer circular groove 105 is connected to the upper oil scraping belt 101 and the lower oil scraping belt 102 through an outer groove bevel 106.

[0030] The angle between the outer upper chamfer 103 and the outer lower chamfer 104 and the end surface (ie, the horizontal position) is 20-45 degrees.

[0031] A through oil return hole 107 is provided at the center of the outer circular groove 105. The oil return hole 107 is a circular or narrow through hole evenly distributed along the circumferential direction of the oil ring body, passing through the outer circular groove and the inner circular groove. The horizontal center line of the oil return hole coincides with the horizontal center line of the bottom of the outer circular groove.

[0032] The cross-sectional profile of the inner circular groove 108 is axisymmetric about the horizontal centerline of the oil ring body 1, and is generally V-shaped or arc-shaped, for accommodating the coil spring. Typically, a V-shaped inner circular groove is used if the oil return hole is circular; if the oil return hole is elongated, either a V-shaped or arc-shaped groove can be used.

[0033] The outer groove bevel angles 106 are symmetrically distributed above and below the central horizontal line of the oil return hole 107, and the included angle is 5-40 degrees.

[0034] The outer circular contours of the cross sections of the upper oil scraping belt 101 and the lower oil scraping belt 102 both include a conical portion and a cylindrical portion, and the sum of the axial heights of the two portions is the width of the oil belt.

[0035] The width of the upper oil scraping belt 101 is twice or more than the width of the lower oil scraping belt 102 .

[0036] The cylindrical portion of the upper oil scraping strip 101 is located on a side close to the outer circular groove 105 ; the cylindrical portion of the lower oil scraping strip 102 is located on a side close to the outer lower chamfer 104 .

[0037] The width of the upper oil scraping belt 101 is 0.6-1.1 mm, and the width of the lower oil scraping belt 102 is 0.18-0.37 mm, preferably 0.25±0.07 mm; the axial height of the cylindrical part of the upper oil scraping belt 101 is 0.03-0.2 mm, and the axial height of the cylindrical part of the lower oil scraping belt 102 is 0.03-0.17 mm, preferably 0.10±0.05 mm.

[0038] The angle between the conical portion and the cylindrical portion of the upper oil scraping belt 101 is 1-5°, and the angle between the conical portion and the cylindrical portion of the lower oil scraping belt 102 is 10-30°, preferably 20°±4°.

[0039] The lower edges of the upper oil scraping belt 101 and the lower oil scraping belt 102 are both provided with sharp rounded corners, and the arc radius is R0.005-0.2mm.

[0040] The radial offset of the highest point of the outer circumferential surface of the upper oil scraping belt 101 and the lower oil scraping belt 102 is less than 0.01 mm.

[0041] Depending on the needs of the application field, a wear-resistant coating can be applied to the outer cylindrical surface, including but not limited to hard chrome plating, chromium plating containing ceramic particles, chromium plating containing diamond particles, nitriding, PVD or DLC, etc.

[0042] The upper oil scraping belt 101 is arranged toward the combustion chamber of the piston, and its working state is as follows: Figure 3 shown.

[0043] The following table compares the performance of the present invention with that of the prior art, taking the existing cylindrical oil strip technology of ISO / GB standard as the comparison benchmark, and setting each comparison item as 10 points:

[0044] The existing oil scraping belts of oil rings include cylindrical oil belts, conical oil belts, step oil belts and arc oil belts. The widths of the upper oil scraping belts and the lower oil scraping belts are the same. The utility model has certain similarities with the existing conical oil belt technology, but the working principles, sizes and appearances of the two are obviously different. The oil ring system of the existing conical oil belt achieves the effect of improving the oil scraping ability by reducing the actual working surface width. Although the oil scraping belt has a conical surface, its total width is small, so its oil distribution ability is weak when it goes up, and it also has a strong upward oil scraping effect when it goes up, which has an adverse effect on the oil consumption rate, friction and reliability. The utility model fully considers the effect of reducing the upward oil scraping effect and increases the oil film thickness retained on the cylinder surface when it goes up, which is beneficial to the oil consumption rate, friction and reliability. The upper and lower oil scraping belts of the existing conical oil belt technology have the same width and taper, and the oil return hole is located in the middle of the ring height center line. The upper and lower oil scraping belts of the utility model have different widths and tapers, and the oil return hole is offset below the ring height center line.

[0045] For the technologies in the comparison group, except for the different forms of the outer circular oil belt, the other parameters and configurations are equivalent.

[0046] The following example illustrates the manufacturing method. The main features of the oil ring are: cylinder diameter φ107mm, material alloy cast iron, outer circle coating is chrome plating, ring height is 3.5mm, radial thickness is 2.8mm, oil return hole type is round hole, and inner circle groove type is V-type.

[0047] The process flow is:

[0048] Oil ring blank → inner and outer circle profiling turning → cutting → flaring inspection → rough grinding of opening → forming turning of outer circle → chrome plating of outer circle → demagnetization → medium grinding of opening → rough honing of outer circle → mechanical edge recognition mark → double end face polishing → forming grinding of outer circle + forming grinding of outer circle groove → outer circle polishing → honing of outer circle oil belt → drilling of oil return hole → turning of inner circle groove → fine grinding of finished product → double end face polishing of finished product → finished product.

[0049] Form grinding of the outer circle + forming grinding of the outer groove are completed successively on the same outer circle forming grinding equipment. The process is broken down as follows:

[0050] Step 1: Design the required template and rollers according to the technical requirements of the product drawings.

[0051] Taking each ring as a unit, the number of oil rings arranged on the template and roller varies depending on the ring height. In this example, 6 oil rings with a ring height of 3.5 mm can be arranged.

[0052] Step 2: Process the template and diamond roller, and engrave the specification marks on the template and roller.

[0053] Step 3: Modify the grinding wheel. On the cylindrical forming grinder, the grinding wheel is shaped and ground by the template and diamond pen. At this time, the outer cylindrical working surface of the grinding wheel has almost the same contour size as the template. The contour is ground by the diamond roller. At this time, the outer cylindrical working surface of the grinding wheel has almost the same contour size as the roller.

[0054] Step 4: Forming grinding: Forming grinding is performed on the external cylindrical forming grinder. At this time, the outer cylindrical part of the oil ring has the required contour size. The forming grinding process parameters are:

[0055] Grinding wheel type: microcrystalline corundum grinding wheel MA120KP-510×25×203 with a grit size of 120.

[0056] Spindle speed: 180~250r / min.

[0057] Grinding speed: The grinding speed varies depending on the material and coating. The grinding speed used in this example is: coarse grinding 0.4~0.6mm / min, fine grinding 0.1~0.3mm / min.

Claims

1. A double oil belt piston oil ring, characterized by: It consists of an oil ring body (1) and a coil spring (2), wherein the coil spring (2) is installed in the inner groove of the oil ring body (1); The outer circumferential surface of the oil ring body (1) is composed of an upper oil scraping belt (101) and a lower oil scraping belt (102); An outer upper chamfer (103) is provided at the junction of the upper scraping belt (101) and the upper end surface (S1) of the oil ring body (1); an outer lower chamfer (104) is provided at the junction of the lower scraping belt (102) and the lower end surface (S2) of the oil ring body (1); an outer circular groove (105) is provided between the upper scraping belt (101) and the lower scraping belt (102); and the outer circular groove (105) is connected to the upper scraping belt (101) and the lower scraping belt (102) via an outer groove bevel (106); An oil return hole (107) is provided at the center of the outer circular groove (105); The cross-sectional outer contours of the upper oil scraping belt (101) and the lower oil scraping belt (102) both include a conical portion and a cylindrical portion, and the sum of the axial heights of the two portions is the width of the oil belt; The width of the upper oil scraping belt (101) is twice or more than the width of the lower oil scraping belt (102); The cylindrical portion of the upper oil scraping belt (101) is arranged on a side close to the outer circular groove (105); the cylindrical portion of the lower oil scraping belt (102) is arranged on a side close to the outer lower chamfer (104); The angle between the conical portion and the cylindrical portion of the upper oil scraping belt (101) is 1-5°, and the angle between the conical portion and the cylindrical portion of the lower oil scraping belt (102) is 10-30°; The upper oil scraping belt (101) is arranged toward the combustion chamber of the piston.

2. The double oil belt piston oil ring according to claim 1, characterized in that: The outer upper chamfer (103) and the outer lower chamfer (104) have an angle of 20-45° with the end face.

3. The double oil belt piston oil ring according to claim 1, characterized in that: The outer groove bevel angles (106) are symmetrically distributed above and below the central horizontal line of the oil return hole (107), and the included angle is 5-40 degrees.

4. The double oil belt piston oil ring according to claim 1, characterized in that: The cross-sectional profile of the inner circular groove (108) is an axisymmetric structure with the horizontal center line of the oil ring body (1) as the axis of symmetry.

5. The double oil belt piston oil ring according to claim 1, characterized in that: The width of the upper oil scraping belt (101) is 0.6-1.1 mm, the width of the lower oil scraping belt (102) is 0.18-0.37 mm, the axial height of the cylindrical portion of the upper oil scraping belt (101) is 0.03-0.2 mm, and the axial height of the cylindrical portion of the lower oil scraping belt (102) is 0.03-0.17 mm.

6. The double oil belt piston oil ring according to claim 1, characterized in that: The lower edges of the upper oil scraping belt (101) and the lower oil scraping belt (102) are both provided with sharp rounded corners, and the arc radius is R0.005-0.2mm.

7. The double oil belt piston oil ring according to claim 1, characterized in that: The radial offset of the highest point of the outer circumferential surface of the upper oil scraping belt (101) and the lower oil scraping belt (102) is less than 0.01 mm.

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