• Title, Summary, Keyword: 캠 형상

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A Multi-Polynomial Synthesis Method for DRRD Cam Profile Optimizations and Effects of Shape Factors on the Cam Lobe Area (DRRD 캠 형상 최적 설계를 위한 다항식 합성법과 캠 로우브 면적에 미치는 형상 계수들의 영향)

  • 김도중;박성태
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.4
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    • pp.59-71
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    • 1994
  • A multi-polynomial method is proposed to synthesize DRRD cam profiles. A cam lift duration s divided into 10 sections, each of them is expressed by a polynomial equation. 12 design variables are extracted from the cam profile displacement, velocity, and acceleration curves. Because all the design variables have physical meanings which are familiar to most cam designers, it is easy to imagine a profile shape from the design variables. The design envelope of the method is wide enough to be used in DRRD automotive cam designs. Polydyne cams, widely used in automotive engines, are included into the envelope. Unlike Polydyne cams, the method provides capability of wide velocity factor variations, which gives much flexibility in flat-faced tappet design. Area factor of profiles designed by the method can be increased 5-10% compared to those of Polydyne cams without increasing acceleration factor. The method is especially useful for cam profile optimizations.

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A Study on the Structure Analysis Optimization of Die Cam Drive Considering the Thin Plate Hardening (박판판재 경화를 고려한 다이 캠 드라이브의 구조해석 최적화에 대한연구)

  • Lee, Jong-Bae;Kim, Seon-Sam;Woo, Chang-Ki
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.5769-5777
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    • 2015
  • According to the forming or bending deformation in the press die, the thin plate occurs a work-hardening, the sheet hardening and cam unit's deformation causes incomplete forming during the cam molding process by the reacting spring forces. This study treated the input parameters of the stress and strain as given properties and also used Cam forming pressure considering the sheet hardening in the forming process of the aluminum sheet. The Hyperstudy are operated be linked with the Abaqus of the finite element analysis tool and the shape of Cam were carried out with non-linear shape optimization analysis. As a result removing the deformation of plate, the cam shape were optimized under conditions reduced deformation, having a minimum stress range and the minimum deformation. Therefore, a stress-strain curve and a normal distribution of stress-thickness can be obtained and optimization could be obtained for the shape of the stress and strain on the die plate hardened cam considering the thickness and reaction force of gas spring as iteration process.

Optimum Cam Profile Design and Experimental Verification on an OHC Type Cam-valve System (OHC형 캠-밸브 기구의 최적 캠 형상설계 및 실험적 검증)

  • 김성훈;김원경;박윤식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.11
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    • pp.2049-2058
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    • 1992
  • In this work, a 6 degree of freedom lumped mass model is constructed for an OHC-type cam valve train analysis, and the model is verified experimentally. Using the verified model, an optimum cam profile is designed to minimize the maximum contact force between cam and follower under the constraints such as cam lift and cam event angle. The designed cam was carefully machined and tested experimentally. As operating the designed cam shaft on the test rig, the valve motion was precisely measured with laser displacement meter and the contact force was indirectly monitored by measuring strain at a certain point of the finger follower. Judging from the model simulation and experiment results, the maximum contact force can be reduced as much as more than 16.7 percent under maintaining the original valve flow area by adopting the optimum cam profile.

Optimum Shape Synthesis of Cam And Follower in Cam-Valve System to Minimize Contact Force (캠-밸브 기구에서 접촉력 최소화를 위한 캠과 종동자 형상 최적 합성)

  • 김성훈;전혁수;박윤식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.3
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    • pp.534-546
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    • 1990
  • In this work, an optimum shape synthesis for rolling contact components was done to minimize contact forces considering dynamic characteristics of the system. Even this method was applied to an OHC type cam follower system, it can be expanded to general rolling contact shape design problems which are strictly forced to follow predetermined motion. First, the follower optimum angular motion was derived to minimize the valve peak acceleration while satisfying all the constraints of valve motion. Then the cam and follower contact shape were synthesized to give the proposed follower motion. Theoretically, two components shape to generate a predetermined motion can not be uniquely determined. So the cam shape was syntehsized with parametric synthesis method to minimize the peak contact force between cam and follower when the follower shape is assumed as a circle or an ellipse.

A Study on Design and Manufacture of Spatial Cams (입체 캠의 형상 설계와 가공에 관한 연구)

  • 김찬봉;양민양
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.6
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    • pp.1361-1371
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    • 1993
  • The effort of this paper is to develop a methodology of computer aided design and manufacture of spatial cams. The integrated CAD/CAM systems for spatial cams are developed to enable manufacturer to design and machine them readily. The contour of spatial cams can be obtained by applying envelope theory to the cam/follower motion. The mathematical cam contour is evaluated at some increment to generate the numerical data for the CNC programming. Incremental generation of points along a cam contour can be accomplished in consideration with the specified tolerance. The computerized procedure is described in detail with accompanying examples.

A Study on the Design of Diesel Engine Cam Profile (디젤엔진용 캠의 형상 설계에 관한 연구)

  • Lee, Wan-Ha;Song, Hwa-Seop;Hong, Jun-Hee
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.15 no.3
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    • pp.104-110
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    • 2006
  • It is a study on the design of a cam profile for diesel engine SOHC. It is used a reverse engineering method without the usual copy processing. It draws up the contour data from an actual cam and processes by CNC. The profile of the cam is reappeared to be up to operational specifications that are the opening and shutting time, lift, speed and acceleration of the inhalation and escape valves. While the cam operating, the noise and vibration are occurred by the sudden change of speed. The new design of cam profile is suitable fur the valve operations to be smooth. We propose the design method of a cam profile far the reappearance of an actual cam. It is proved to be the propriety about the design of the cam profile through the processing, measurement, and comparison of the cam profile.

A Study on the Cam Profile Synthesis Method for Automotive Engines Using Hermite Curve (Hermite 곡선을 이용한 자동차 엔진 캠 형상 합성법에 관한 연구)

  • Kim, D.J.;Lee, J.W.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.5
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    • pp.90-99
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    • 1995
  • A numerical method is proposed to synthesize automotive cam profiles. An arbitrary acceleration profile for the cam follower motion is divided into several segments, each of them is described by a Hermite curve. A cam profile is defined by control point locations and control variables assigned to each segment. Closed form equations are derived for velocity and displacement constraints which should be satisfied for the curve to be a cam profile. Because the method is flexible and provide arbitrary local controllability, any types of cam acceleration profile can be reproduced by the method. The method is expecially useful for the design of roller type OHC valve trains which need precise local control in the cam profile design to avoid under-cutting problems.

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A Study on the Optimal Design of Automotive Cam Profiles using Hermite Curve (Hermite 곡선을 이용한 자동차 엔진 캠 형상의 최적 설계에 관한 연구)

  • 김도중;김원현
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.4
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    • pp.129-140
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    • 1998
  • A numerical method is proposed to optimize automotive cam profiles. An acceleration curve of a cam follower motion is described by Hermite spline curves. Because of the intrinsic characteristics of the Hermite curve, it is possible to design an acceleration curve with arbitrary shape. Design variables in the optimization problem are location of control points which define the acceleration curve. Objective function includes dynamic performances as well as kinematic properties of a valve train. Similar optimization procedure was also performed using Polydyne cam profile synthesis method. Optimized profiles using the Hermite curve are proved to be superior to those using the Polydyne method.

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A CAD/CAM System for Plate Cams with Three CNC Interpolation Methods (세가지 보간방법을 이용한 평판 캠의 CAD/CAM 시스템)

  • 김찬봉;양민양
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.3
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    • pp.869-879
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    • 1991
  • 본 연구에서는 여러가지 평판 캠 기구에 대하여 효율적이며 정밀한 설계 및 가공을 할 수 있도록 CAD/CAM 소프트웨어를 개발하는데 목적이 있다. 즉, 주어진 캠 곡선과 캠 기구의 구성조건을 바탕으로 포락선 이론에 의하여 캠 형상을 구하고, 원하 는 가공 방법을 선정하여 황삭가공과 정삭가공에 대한 NC 파트프로그램을 얻는 기능들 을 하나의 통합된 CAD/CAM 소프트웨어로 구성하여 생산성과 효율성 및 정밀성 향상에 기여하고자 한다.