Tolerances of Form(Form Errors) for a Hydraulic valve

100 %
0 %
Information about Tolerances of Form(Form Errors) for a Hydraulic valve
Technology

Published on February 25, 2014

Author: hycomengineering

Source: slideshare.net

Description

Four types of Form errors must be within a restricted limit in hydraulic valve parts. The circularity, straightness and cylindricity are very critical to quality in spool and spool bore in valve body. The flatness is very important to the faces of valve body sections in a sectional DC valve.

Tolerances of Form(Form Errors) for a Hydraulic valve Four types of Form errors must be within a restricted limit in hydraulic valve parts. The circularity, straightness and cylindricity are very critical to quality in spool and spool bore in valve body. The flatness is very important to the faces of valve body sections in a sectional DC valve. Straightness Circularity Flatness Cylindricity

Straightness (Surface Elements) 0.1 0.1 Tolerance Zone MMC 0.1 Tolerance Zone MMC 0.1 Tolerance Zone MMC In this example each longitudinal element of the surface must lie within a tolerance zone defined by two parallel lines separated by the specified tolerance value. The feature must be within the limits of size and the boundary of perfect form at MMC. Any barreling or waisting of the feature must not exceed the size limits of the feature.

Straightness (RFS) 0.1 0.1 Diameter Tolerance Zone MMC Outer Boundary (Max) Outer Boundary = Actual Feature Size + Straightness Tolerance In this example the derived median line of the feature’s actual local size must lie within a tolerance zone defined by a cylinder whose diameter is equal to the specified tolerance value regardless of the feature size. Each circular element of the feature must be within the specified limits of size. However, the boundary of perfect form at MMC can be violated up to the maximum outer boundary or virtual condition diameter.

Straightness (MMC) 16.00 1 15.85 0.1 16 (MMC) M 0.1 Diameter Tolerance Zone 16.1 Virtual Condition 15.85 (LMC) 0.25 Diameter Tolerance Zone 16.1 Virtual Condition Virtual Condition = MMC Feature Size + Straightness Tolerance In this example, the derived median line of the feature’s actual local size must lie within a tolerance zone defined by a cylinder whose diameter is equal to the specified tolerance value at MMC. As each circular element of the feature departs from MMC, the diameter of the tolerance cylinder is allowed to increase by an amount equal to the departure from the local MMC size. Each circular element of the feature must be within the specified limits of size. However, the boundary of perfect form at MMC can be violated up to the virtual condition diameter.

Circularity (Roundness) 0.1 90 0.1 90 0.1 Wide Tolerance Zone In this example each circular element of the surface must lie within a tolerance zone defined by two concentric circles separated by the specified tolerance value. All points on the surface must lie within the limits of size and the circularity limit. Circularity is the condition of a surface where all points of the surface intersected by any plane perpendicular to a common axis are equidistant from that axis. The circularity tolerance must be less than the size tolerance

Cylindricity 0.1 0.1 Tolerance Zone MMC Barrel shape In this example the entire surface must lie within a tolerance zone defined by two concentric cylinders separated by the specified tolerance value. All points on the surface must lie within the limits of size and the cylindricity limit. Cylindricity is the condition of a surface of revolution in which all points are equidistant from a common axis. Cylindricity is a composite control of form which includes circularity (roundness), straightness, and taper of a cylindrical feature.

Extreme Variations of Form Allowed By Size Tolerance for spool bore on valve body 20.1 20 20 (MMC) Banana shape or camber 20.1 (LMC) 20.1 (LMC) 20 (MMC) MMC Perfect Form Boundary Taper 20.1 (LMC)

Extreme Variations of Form Allowed By Size Tolerance for spool OD 20 19.9 19.9 (LMC) Banana shape 20 (MMC) 19.9 (LMC) MMC Perfect Form Boundary Taper 19.9 (LMC) 20 (MMC)

Extreme Variations of Form Allowed By Size Tolerance 20.1 20 20 (MMC) 20 19.9 20.1 (LMC) 20 (MMC) 19.9 (LMC) 20.1 (LMC) 20 (MMC) 19.9 (LMC) MMC Perfect Form Boundary 20(MM C) 20.1 (LMC) 24.9 (LMC)

Flatness 0.1 25 +/-0.25 0.1 Tolerance Zone 0.1 Tolerance Zone 24.75 min 25.25 max In this example the entire surface must lie within a tolerance zone defined by two parallel planes separated by the specified tolerance value. All points on the surface must lie within the limits of size and the flatness limit. Flatness is the condition of a surface having all elements in one plane. Flatness must fall within the limits of size. The flatness tolerance must be less than the size tolerance.

Add a comment

Related presentations

Related pages

Tolerances of Form(Form Errors) for a Hydraulic valve

Tolerances of Form(Form Errors) for a Hydraulic valve Straightness Flatness Circularity Cylindricity Four types of Form ...
Read more

Articles - Hycom Engineering Pvt. Ltd. - Contract ...

Articles: Read : Form tolerances in Hydraulic Valves : Four types of Form errors must be within a restricted limit in hydraulic valve parts. The ...
Read more

Hydraulic Valve | LinkedIn

Designer at Parker Hydraulic Valve Division Past Drafter / Designer at Bettcher Industries Education
Read more

Error tolerance - HAWE Oil-Hydraulic Technology China

电子邮件已发送 x. 发至 (电子邮件):
Read more

Patent US3272232 - Distribution block for hydraulic valve ...

... 1966 R. LAUMO NT DISTRIBUTION BLOCK FOR HYDRAULIC VALVE ... of a hydraulic valve in the form of a casing ... PATENTS 2,651,324 9 ...
Read more

Innovative Braking and Controls Worldwide

Innovative Braking and Controls Worldwide Hydraulic Brake Valves ... MICO, Inc. is not responsible for errors, ...
Read more

Engineering Essentials: Fundamentals of Hydraulic Pumps ...

... Fundamentals of Hydraulic ... draws liquid from the reservoir through the inlet check valve into the ... of the gear teeth forms a ...
Read more

Accumulator Charging Valves - MICO designs, manufacturers ...

Accumulator Charging Valves ... These MICO® Dual Accumulator Charging Valves per-form ... The MICO® Full Power Power Brake Valves use the hydraulic ...
Read more