Piston ring, raw material therefor, and production method for both

A manufacturing method and technology of piston rings, applied in the field of piston rings, can solve problems such as difficult manufacturing methods and material properties, difficulty in reducing weight and narrowing width, reliability is not practical, etc., achieve excellent thermal fatigue resistance, reduce removal amount , Excellent sealing effect

Active Publication Date: 2016-01-27
RIKEN CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] However, when it is used as a large ring for marine engines, etc., the cross-sectional area of ​​the ring also increases, so the steel wire used also needs to have a wire with a larger cross-sectional area.
Tempering of large rings formed from wire rods has not progressed due to the difficulty in handling wire rods with large cross-sectional areas and the enlargement of rolling mills or heat treatment equipment
In particular, precision molding is difficult, so it is also difficult to narrow the width related to weight reduction and low tension
Furthermore, Japanese Patent Application Laid-Open No. 6-221436 discloses a cast steel piston ring material in which a special steel is formed into a ring shape by a casting method. However, as a result, there are no casting defects such as blowholes and pinholes caused by the casting method and the material. The characteristics are difficult to establish at the same time, the actual situation is that the reliability has not yet been practical

Method used

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  • Piston ring, raw material therefor, and production method for both
  • Piston ring, raw material therefor, and production method for both
  • Piston ring, raw material therefor, and production method for both

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0064] Heat a bar steel of SUS420J2 material with an outer diameter of 110mm and a length of 200mm to 1000°C, press and form it into a disc shaped body with an outer diameter of 165mm and a height of about 90mm, and then form a concave part in the center with a core punch, and penetrate it , Open a hole, and make the first cylindrical raw material with an outer diameter of about 180mm and an inner diameter of about 50mm. Next, the first cylindrical raw material is reheated by a high-frequency induction heating device, installed in a hole-enlarging machine, and rolled to produce a second cylindrical material with an outer diameter of about 364 mm, an inner diameter of about 332 mm, and a width of about 110 mm. Two cylindrical raw materials. After the second cylindrical raw material was annealed at 790°C for 10 hours, after the scale was removed by sandblasting, the inner and outer peripheries were simultaneously rough-machined into a non-circular shape (elliptical shape) with a...

Embodiment 2

[0072] Using steel materials with the same composition as in Example 1, a second cylindrical raw material having an outer diameter of about 368 mm, an inner diameter of about 339 mm, and a width of about 120 mm was produced by rolling and reaming, and the cylindrical raw material was heated again. Press forming is carried out in a direction perpendicular to the axis, and formed into a non-circular cylindrical material with a major axis of 370 mm and a minor axis of 364 mm. In this press forming, a lower mold and an upper mold having a predetermined elliptical shape are used. The obtained noncircular cylindrical raw material was subjected to annealing and descaling by sandblasting in the same manner as in Example 1, followed by simultaneous processing of inner and outer peripheries and piercing processing to obtain 8 noncircular rings. In the same manner as in Example 1, after quenching and tempering, finishing was performed, and then nitriding and thermal spraying were perform...

Embodiment 3～7

[0074] From the second cylindrical material with an outer diameter of about 368 mm, an inner diameter of about 339 mm, and a width of about 120 mm produced in Example 2, except that the nominal diameter (d1) was set to 350 mm, the ring width (h1) and radial thickness ( a1) The numerical values ​​shown in Table 1 were used, and eight pressure rings were produced for each example in the same manner as in Example 2, except that the tension Ft was adjusted so that the surface pressure would be 0.08 MPa. Table 1 shows the dimensional relationship and the tension Ft relationship, and Table 2 shows the measurement results of the weight and flatness measured in the same manner as in Example 1, and the weight ratio and followability coefficient ratio relative to Comparative Example 1, and also The results of Example 1 and Comparative Example 1 are included. Here, the Young's modulus (E) of the steel material of Example 1 is set to 215 GPa, and the Young's modulus (E) of the cast iron o...

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Abstract

In order to provide a large steel ring that is lighter and thereby contributes to improved fuel consumption, that has lower tensile strength, and has excellent wear resistance and scuffing resistance, and in order to also provide a raw material therefor and a production method for both, a large steel ring having reduced ring width (h1) and radial direction thickness (a1), and having a nominal diameter (d1) of at least 200 mm but less than 1,100 mm is obtained from a hot-forged cylindrical steel material by combining: steel including as compulsory alloy elements C, Si, Mn, and Cr, including as optional alloy elements Ni, V, and Mo, and having the thermal conductivity and/or resistance to thermal degradation thereof adjusted; and hot forging that includes a ring rolling step.

Description

technical field [0001] The present invention relates to piston rings (hereinafter also referred to as "rings"), and more particularly to large steel piston rings (hereinafter also referred to as "large rings"), their raw materials, and their manufacturing methods. Background technique [0002] Among the large rings used in large diesel engines, cast iron piston rings with excellent heat resistance and wear resistance are the mainstream. However, in recent years, in large diesel engines, there has been an increase in output and efficiency (CO 2 In particular, due to the increase of the effective pressure of the cylinder, the maximum pressure, the increase of the acting stress caused by the increase of the thermal load, or the increase of the average piston speed, etc., the operating environment is becoming increasingly severe. For example, in the top ring of a low-speed 2-stroke diesel engine, CV (Compacted Vermicular) graphite cast iron is used between flake graphite cast i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): F16J9/12B21H1/06B21J5/08B21J5/10B21K1/18C21D1/06C21D9/40C22C38/00C22C38/32C22C38/46F02F5/00F16J9/26
CPCB21J1/04B21J1/06B21J5/00B21J5/10B23P15/06C21D7/13C21D9/40C21D2211/004C21D2211/008C22C38/02C22C38/04C22C38/22C22C38/24C22C38/32C22C38/40C22C38/44C22C38/46F16J9/26B21H1/06B21J5/08B21K1/18C21D1/06C22C37/08C22C37/10F16J9/062F16J9/20
Inventor 川西实掛川聪岛祐司
Owner RIKEN CO LTD
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