Stepped oil ring and oil belt processing method

Abstract

The invention discloses a stepped oil ring and oil belt machining method. The method comprises the following steps that a diamond roller is designed and manufactured according to the outer contour of an oil ring; on an outer circle forming grinding machine, a grinding wheel for forming grinding is trimmed through a diamond roller, so that the outer circle working face of the grinding wheel forms the contour size consistent with that of the diamond roller; the oil ring is formed and ground on an outer circle forming grinding machine, the step part of the outer circle of the oil ring is ground firstly, the step part is reserved, and then the groove profile of the outer circle of the oil ring is ground. According to the machining method, two-time clamping is not needed, a one-time forming and grinding method is adopted, the outer circle step, the outer circle groove and the outer chamfer are machined at a time, the consistency of the width of the step oil belt is good, the machining efficiency is improved, and the batch production requirement is met.

Description

Technical Field

[0001] The invention relates to the technical field of piston ring processing, in particular to a method for processing a stepped oil ring oil belt. Background Art

[0002] Step oil rings are now widely used in the market. The key structure of this type of product lies in the stepped portion of the outer oil belt. The existing processing technology adopts a two-step method to process. The first step is to grind the stepped portion of the outer circle of the oil ring with a grinding wheel with a stepped profile, then the workpiece is offset, and then the outermost part of the stepped oil belt is ground and corrected with a second grinding wheel with a flat outer circle to make it smooth and flat. After a batch of products are processed in the first step, the second step is carried out. At this time, another forming grinder with the required grinding wheel profile size is replaced, or the previous forming grinder is still used, but another diamond roller is used to correct the grinding wheel to obtain the required outer circle profile size. After this step of forming grinding, the required outer circle groove, outer groove bevel, outer upper chamfer and outer lower chamfer are generated, and the required stepped oil belt is left on the outer circle. At this time, the processing of the outer circle profile size of the oil ring is completed. In this process, the oil ring needs to be clamped twice. Affected by the cumulative error of the ring height size and the assembly accuracy, this will cause the width dispersion of the effective contact zone of the outer layer of the stepped oil belt to be too large, even exceeding the upper and lower limits of the required width. On the other hand, the grinding of the outer circle is completed by clamping twice, and the processing efficiency is low. Summary of the invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the background technology, the present invention seeks protection for a method for processing a stepped oil ring and an oil belt.

[0004] Technical solution: The step oil ring oil belt processing method disclosed in the present invention comprises the following steps: S1. Design and manufacture diamond roller according to the outer contour of oil ring; S2. On the cylindrical profile grinder, the profile grinding wheel is trimmed by a diamond roller so that the outer cylindrical working surface forms a profile size consistent with that of the diamond roller; S3. Perform profile grinding on the oil ring on an external cylindrical grinder. First, grind the stepped portion of the outer circle of the oil ring, retain the stepped portion, and then grind the outer groove of the oil ring.

[0005] Furthermore, on the cylindrical forming grinder, a plurality of oil rings are arranged side by side to form a group of grinding units.

[0006] Furthermore, on the external cylindrical forming grinder, two grinding wheels are axially arranged in parallel, the first grinding wheel is dressed to form the stepped portion contour of the oil ring, and the second grinding wheel is dressed to form the outer upper chamfer, outer lower chamfer, outer groove bevel and outer circular groove portion contour of the oil ring, and the oil ring is ground by the two grinding wheels in sequence.

[0007] Furthermore, the grinding parameters of the first grinding wheel are: a rough grinding feed rate of 0.4 mm / min, and a fine grinding feed rate of 0.1 mm / min.

[0008] Furthermore, the first grinding wheel is dressed with a diamond roller with the following requirements: 1 dressing per cycle, 0.08 mm per dressing amount.

[0009] Furthermore, the grinding parameters of the second grinding wheel are as follows: the grinding speed is 0.4-0.6 mm / min for rough grinding and 0.1-0.3 mm / min for fine grinding.

[0010] Furthermore, the second grinding wheel is dressed with a diamond roller. The requirements are: dressing once every 5 cycles, and the dressing amount each time is 0.02-0.08mm.

[0011] Beneficial effects: Compared with the prior art, the advantages of the present invention are: no need for two clampings, and the one-time forming grinding method is adopted to complete the processing of the outer cylindrical step, outer cylindrical groove and outer chamfer at one time. The consistency of the step oil belt width is good, the processing efficiency is improved, and the requirements of mass production are met; in actual manufacturing, the accuracy of the effective contact belt width of the step oil belt outer layer is doubled, the processing efficiency is improved by 50%, and the total cost is reduced by 50%, which has good application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a cross-sectional view of a stepped oil ring of the present invention; Figure 2 It is a schematic diagram of the oil ring grinding process of the present invention; Figure 3 This is a schematic diagram of the positions of the first grinding wheel and the oil ring of the present invention; Figure 4 This is a diagram showing the changes in the oil ring of the present invention when it is ground by the first grinding wheel; Figure 5 This is a schematic diagram of the positions of the second grinding wheel and the oil ring of the present invention; Figure 6 This is a diagram showing the changes in the oil ring of the present invention after being ground by the second grinding wheel. DETAILED DESCRIPTION

[0013] Take a case to illustrate the step oil ring oil belt processing method of the present invention. Figure 1 As shown, the main features of the stepped oil ring are: cylinder diameter φ100mm, material is alloy cast iron, outer circle coating is chrome-plated, ring height is 3.0mm, radial thickness is 2.5mm, and the oil return hole type is a round hole.

[0014] The process flow is: Oil ring blank → inner and outer circle profiling turning → cutting → expansion inspection → rough grinding opening → outer circle forming turning → outer circle chrome plating → demagnetization → medium grinding opening → outer circle rough honing → mechanical edge recognition mark → double end surface polishing → outer circle forming grinding → outer circle polishing → drilling oil return hole → inner circle groove turning → outer circle honing → finished product fine grinding opening → brushing outer / inner circle burrs → double end surface finished product polishing → finished product.

[0015] The key process of the present invention, namely the outer circle forming grinding process, is described in detail as follows: It is completed continuously on two grinding wheels of the same cylindrical profile grinding equipment. The decomposition steps are as follows: Step 1: According to the technical requirements of the product drawings, design and customize the required diamond rollers, and engrave the specification marks on the rollers. The number of oil rings arranged on the rollers varies depending on the ring height. In this example, 7 oil rings with a ring height of 3.0 mm are arranged, that is, 7 oil rings form a grinding unit.

[0016] Step 2: Dressing the grinding wheel. On the cylindrical profile grinder, the diamond roller is used to dress the profiled grinding wheel. At this time, the outer cylindrical working surface of the grinding wheel has almost the same contour size as the working part of the roller.

[0017] Step 3: Profile grinding: profile grinding the oil ring on a cylindrical profile grinder.

[0018] Grinding wheel type: microcrystalline corundum grinding wheel MA120L8-510×25×203 with a grit size of 120.

[0019] Spindle speed: 180-250r / min.

[0020] Specifically, this step is divided into three processes, such as Figure 2 As shown: Process 1: Align the surface / mount the rack. Make the end face of the oil ring with the mechanical edge recognition mark face in the same direction. This face is the upper end face. Put the aligned oil ring into the mounting rack on the grinder. Figure 3 and 5 shown.

[0021] Process 2: At the first grinding wheel, grind the stepped portion of the outer circle of the oil ring assembly to produce the required step profile and corresponding dimensions, such as Figure 4 shown.

[0022] The process requires high accuracy of profile dimensions, especially the depth of the step part is only about 0.05mm. The grinding parameters are set as follows: rough grinding feed speed 0.4mm / min, fine grinding feed speed 0.1mm / min, and the requirements for dressing the grinding wheel with diamond roller: dressing once per cycle, each dressing amount 0.08mm, and timely dressing of the grinding wheel to ensure that the profile size of the grinding wheel is maintained.

[0023] Process 3: The oil ring group is offset to the second grinding wheel, and the outer groove shape is ground to produce the required outer groove, outer groove bevel, outer upper chamfer and outer lower chamfer, and leave the required outer circle finished step, such as Figure 6 shown.

[0024] The grinding speed is: 0.4-0.6mm / min for rough grinding and 0.1-0.3mm / min for fine grinding. The requirements for dressing the grinding wheel with a diamond roller are: dressing once every 5 cycles, and the dressing amount each time is 0.02-0.08mm.

[0025] The other processes are well known in the piston ring industry and will not be described in detail.

Claims

1. A method for processing a stepped oil ring oil belt, characterized in that: The following steps are involved: S1. Design and manufacture diamond roller according to the outer contour of oil ring; S2. On the cylindrical profile grinder, the profile grinding wheel is trimmed by a diamond roller so that the outer cylindrical working surface forms a profile size consistent with that of the diamond roller; S3. Perform profile grinding on the oil ring on an external cylindrical grinder. First, grind the stepped portion of the outer circle of the oil ring, retain the stepped portion, and then grind the outer groove of the oil ring.

2. The step oil ring oil belt processing method according to claim 1, characterized in that: On a cylindrical profile grinder, multiple oil rings are arranged side by side to form a group of grinding units.

3. The step oil ring oil belt processing method according to claim 1 is characterized in that: On the external cylindrical forming grinder, two grinding wheels are axially arranged in parallel. The first grinding wheel is dressed to form the stepped part contour of the oil ring, and the second grinding wheel is dressed to form the outer upper chamfer, outer lower chamfer, outer groove bevel and outer circular groove part contour of the oil ring. The oil ring is ground by the two grinding wheels in turn.

4. The step oil ring oil belt processing method according to claim 3 is characterized in that: The grinding parameters of the first grinding wheel are: rough grinding feed speed 0.4mm / min, fine grinding feed speed 0.1mm / min.

5. The step oil ring oil belt processing method according to claim 4 is characterized in that: The first grinding wheel is dressed with a diamond roller. The requirements are: dress once per cycle, and the dressing amount is 0.08mm each time.

6. The step oil ring oil belt processing method according to claim 3 is characterized in that: The grinding parameters of the second grinding wheel are: grinding speed is 0.4-0.6mm / min for rough grinding and 0.1-0.3mm / min for fine grinding.

7. The step oil ring oil belt processing method according to claim 6, characterized in that: The second grinding wheel is dressed with a diamond roller. The requirements are: dress once every 5 cycles, and the dressing amount each time is 0.02-0.08mm.

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