Double-oil-belt piston oil ring

Abstract

The invention 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 installed 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. The effect of reducing upward oil scraping is fully considered, the thickness of an oil film reserved on the surface of the air cylinder during ascending is increased, and therefore the oil consumption rate, friction and reliability are facilitated.

Description

Technical Field

[0001] The invention 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 the internal combustion engine includes the cylinder, piston, piston ring, piston pin and other parts. As moving parts, they are lubricated by the oil splashing and / or spraying on the inner wall of the cylinder to achieve good working effect. For a four-stroke internal combustion engine, in order to prevent the oil of each stroke from remaining too much on the inner wall of the cylinder and being transported to the combustion chamber on the top of the piston and burned, the piston ring, especially the oil ring, plays a vital role. When the oil ring moves up and down in the cylinder with the piston, its outer circle oil scraper will scrape off the excess oil and distribute a layer of oil film in the cylinder to provide lubrication for the friction pair.

[0003] As a standardized part, ISO / GB standard has some conventional requirements for oil rings. Basically, it has two oil scraping belts on the outer cylindrical surface, and has elastic force that allows the oil scraping belt to fit closely to the cylinder wall. The elastic force mainly comes from the coil spring installed inside it. At the same time, it has an oil return hole that runs through the inside and outside, so that the scraped oil can flow back to the oil pan of the internal combustion engine through here. Obviously, achieving better oil scraping ability, that is, lower oil consumption rate, and achieving lower friction power consumption, that is, lower fuel consumption rate, and maintaining good reliability and durability are the continuous pursuits of engineers in this field.

[0004] For the outer circle oil scraper, in addition to the conventional cylindrical oil scraper, there are now step oil scraper, conical oil scraper, arc oil scraper and other structures, which have been widely used, but in essence, they play the role of reducing the actual contact width between the oil scraper and the cylinder, and can achieve a higher contact pressure under a lower elastic force, thus reducing the oil consumption rate to a certain extent. But on the other hand, it has been found in practice that when the current oil ring moves upward with the piston, the oil ring still has a strong upward oil scraping effect, resulting in very little oil remaining on the surface of the cylinder, which is not conducive to the lubrication of the friction pair. At the same time, the oil scraped to the combustion chamber increases the amount of carbon deposits, resulting in an increase in carbon deposits on the ring surface and the ring groove, and there is a risk of the piston ring getting stuck in the ring groove and failing, which is also not conducive to further reducing the oil consumption. Summary of the invention

[0005] Purpose of the invention: In order to overcome the shortcomings of the background technology, the present invention seeks protection for a double-oil-belt piston oil ring.

[0006] Technical solution: The double-oil-belt piston oil ring disclosed in the present invention 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; The outer circumferential surface of the oil ring body is composed of an upper oil scraping belt and a lower oil scraping belt; An outer upper chamfer is provided at the place where the upper scraper belt is connected to the upper end surface of the oil ring body, and an outer lower chamfer is provided at the place where the lower scraper belt is connected to the lower end surface of the oil ring body. An outer circular groove is formed between the upper scraper belt and the lower scraper belt, and the outer circular groove is connected to the upper scraper belt and the lower scraper belt through an outer groove bevel. A penetrating oil return hole is provided at the center of the outer circular groove; The cross-sectional outer contours of the upper and lower oil scraping belts 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 is twice or more than the width of the lower oil scraping belt; 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; The angle between the conical part and the cylindrical part of the upper oil scraping belt is 1-5°, and the angle between the conical part and the cylindrical part of the lower oil scraping belt is 10-30°; The upper oil scraping belt is arranged toward the combustion chamber of the piston.

[0007] Furthermore, the outer upper chamfer and the outer lower chamfer form an angle of 20-45° with the end face.

[0008] Furthermore, the outer groove oblique angles are symmetrically distributed on both sides above and below the central horizontal line of the oil return hole, and the included angle is 5-40°.

[0009] 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.

[0010] 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.

[0011] Furthermore, the lower edges of the upper and lower oil scraping belts are both provided with chamfered rounded corners, and the arc radius is R0.005-0.2mm.

[0012] Furthermore, the radial offset of the highest point of the outer circumferential surface of the upper and lower oil scraping belts is less than 0.01 mm.

[0013] Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows: the upper and lower oil scraping belts 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

[0014] Figure 1 It is the overall front view of the present invention; Figure 2 It is a radial cross-sectional view of the present invention; Figure 3 This is a diagram showing the effect of scraping oil from the oil cloth of the present invention. DETAILED DESCRIPTION

[0015] 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.

[0016] The base material of the oil ring body 1 is one of gray cast iron, alloy cast iron, ductile iron and steel.

[0017] like Figure 2 As shown, the oil ring body includes an upper end face, a lower end face, an outer circle, an inner circle surface, an outer circle groove, an inner circle groove and an oil return hole.

[0018] 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 .

[0019] An outer upper chamfer 103 is provided at the place where the upper 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 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 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 through an outer groove bevel 106.

[0020] The included angles between the outer upper chamfer 103 and the outer lower chamfer 104 and the end surface (ie, the horizontal position) are 20-45°.

[0021] A penetrating oil return hole 107 is arranged 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, penetrating 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.

[0022] 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, and is generally a V-shaped or arc-shaped groove for accommodating the coil spring. Typically, if the oil return hole is circular, a V-shaped inner circular groove is used; if the oil return hole is narrow and long, either a V-shaped inner circular groove or an arc-shaped inner circular groove can be used.

[0023] 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°.

[0024] 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.

[0025] The width of the upper oil scraping belt 101 is twice or more than the width of the lower oil scraping belt 102 .

[0026] The cylindrical portion of the upper oil scraping belt 101 is disposed on a side close to the outer circular groove 105 ; the cylindrical portion of the lower oil scraping belt 102 is disposed on a side close to the outer lower chamfer 104 .

[0027] The width of the upper scraper belt 101 is 0.6-1.1 mm, and the width of the lower scraper belt 102 is 0.18-0.37 mm, preferably 0.25±0.07 mm; the axial height of the cylindrical part of the upper scraper belt 101 is 0.03-0.2 mm, and the axial height of the cylindrical part of the lower scraper belt 102 is 0.03-0.17 mm, preferably 0.10±0.05 mm.

[0028] The angle between the conical part and the cylindrical part of the upper scraping belt 101 is 1-5°, and the angle between the conical part and the cylindrical part of the lower scraping belt 102 is 10-30°, preferably 20°±4°.

[0029] The lower edges of the upper oil scraping belt 101 and the lower oil scraping belt 102 are both provided with chamfered rounded corners, and the arc radius is R0.005-0.2mm.

[0030] 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.

[0031] Depending on the needs of the application field, a wear-resistant coating may 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.

[0032] 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.

[0033] The performance of the present invention is compared with that of the prior art, with the existing cylindrical oil belt technology of ISO / GB standard as the comparison benchmark: The existing oil scraping belt of the oil ring includes a cylindrical oil belt, a conical oil belt, a step oil belt and an arc oil belt. The width of the upper scraping belt and the lower scraping belt is the same. The present invention has certain similarities with the existing conical oil belt technology, but the working principle, size and appearance of the two are obviously different. The oil ring of the existing conical oil belt achieves the effect of improving the scraping ability by reducing the actual working surface width. Since the scraping belt has a conical surface, but its total width is small, the oil distribution ability is weak when it is moving upward, and it also has a strong upward scraping effect when it is moving upward, which has an adverse effect on the oil consumption rate, friction and reliability. The present invention fully considers the effect of reducing the upward scraping effect and increases the thickness of the oil film retained on the cylinder surface when moving upward, which is beneficial to the oil consumption rate, friction and reliability. The upper scraping belt and the lower scraping belt of the existing conical oil belt technology have the same width and the same taper, and the oil return hole is located in the middle of the center line of the ring height. The upper scraping belt and the lower 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.

[0034] 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.

[0035] The following example is used to illustrate the manufacturing method. The main features of the oil ring are: cylinder diameter φ107mm, material alloy cast iron, outer circle coating is chrome-plated, 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.

[0036] The process flow is: Oil ring blank → inner and outer circle profiling turning → cutting → expansion inspection → rough grinding opening → forming turning outer circle → outer circle chrome plating → demagnetization → medium grinding opening → outer circle rough honing → mechanical edge recognition mark → double end face polishing → forming grinding outer circle + forming grinding outer circle groove → outer circle polishing → honing outer circle oil belt → drilling oil return hole → turning inner circle groove → finished product fine grinding → finished product with double end faces polishing.

[0037] External cylindrical profile grinding + external cylindrical groove profile grinding are completed successively on the same external cylindrical profile grinding equipment. The process is broken down as follows: Step 1: Design the required template and rollers according to the technical requirements of the product drawings.

[0038] Taking each ring as a unit, the number of oil rings arranged on the template and the roller varies depending on the ring height. In this example, 6 oil rings with a ring height of 3.5 mm can be arranged.

[0039] Step 2: Process the mastering template and diamond roller, and engrave the specification marks on the template and roller.

[0040] 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.

[0041] Step 4: Forming grinding: Forming grinding is performed on the external cylindrical grinding machine. At this time, the outer cylindrical part of the oil ring has the required contour size. The forming grinding process parameters are: Grinding wheel type: microcrystalline corundum grinding wheel MA120KP-510×25×203 with a grit size of 120.

[0042] Spindle speed: 180~250r / min.

[0043] Grinding speed: The grinding speed varies depending on the material and coating. The grinding speed used in this example is: rough grinding 0.4~0.6mm / min, fine grinding 0.1~0.3mm / min.

Claims

1. A double oil belt piston oil ring, characterized in that: It is composed of an oil ring body (1) and a coil spring (2), wherein the coil spring (2) is installed in the inner circular 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 a location where the upper scraper belt (101) and the upper end surface (S1) of the oil ring body (1) meet, an outer lower chamfer (104) is provided at a location where the lower scraper belt (102) and the lower end surface (S2) of the oil ring body (1) meet, an outer circular groove (105) is provided between the upper scraper belt (101) and the lower scraper belt (102), and the outer circular groove (105) is connected to the upper scraper belt (101) and the lower scraper 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 circular contours of the upper oil scraping belt (101) and the lower oil scraping belt (102) both include a conical surface portion and a cylindrical surface 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 part and the cylindrical part of the upper oil scraping belt (101) is 1-5°, and the angle between the conical part and the cylindrical part 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 surface.

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°.

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 chamfered 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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