Hydraulic pressure control valve

A hydraulic pressure control valve comprising:

• a cylindrical casing having a plurality of first lands formed on its inner circumferential surface at specified intervals and being in communication with a plurality of pressurized oil destinations, and a groove formed between each of said lands, alternate grooves being in communication with a high pressure source;
• and
• a valve body rotatably disposed in said casing and having additional lands of the same number as said first lands and formed on the peripheral surface of the valve body at specified intervals, the additional lands comprising second, third and fourth lands;
• said second lands being disposed in a circumferential direction opposite to said alternate grooves in communication with a high pressure source;
• said third lands being in communication with a low pressure source and disposed between alternate said second lands;
• said fourth lands being disposed in the remaining lands, between alternate said second lands, said fourth lands being disconnected from the low pressure source, and forming communicating portions between adjacent first lands of said casing via said fourth lands;
• and
• notches disposed at corners of one of said valve body and said casing, said notches opposing each other across the communicating portions on both sides of said fourth lands, said notches configured such that, until relative angular displacement between the valve body and casing reaches a predetermined magnitude, variations of the communicating portions is substantially not produced by said relative angular displacement.

A hydraulic pressure control valve comprising:

• a cylindrical casing having a plurality of first grooves formed on its inner circumferential surface at specified intervals and being in communication with a plurality of pressurized oil destinations, and a land formed between each of said grooves, alternate lands being in communication with a high pressure source;
• and
• a valve body rotatably disposed in said casing and having additional grooves of the same number as said first grooves and formed on the peripheral surface of the valve body at specified intervals, the additional grooves comprising second, third and fourth grooves;
• said second grooves being disposed in a circumferential direction opposite to said alternate lands in communication with a high pressure source;
• said third grooves being in communication with a low pressure source and disposed between alternate said second grooves;
• said fourth grooves being disposed in the remaining grooves, between alternate said second grooves, said fourth grooves being disconnected from the low pressure source, and forming communicating portions between adjacent first grooves of said casing via said fourth grooves;
• and
• notches disposed at corners of one of said valve body and said casing, each notch including a first portion substantially parallel to one of the inner circumferential surface of said casing and the peripheral surface of said valve body, and a second portion having an axial sectional shape forming a circular arc and having a radius approximately equal to the radial depth from said one of said inner circumferential surface and the peripheral surface in said first portion, wherein said second portion links said first portion and said one of said inner circumferential surface or peripheral surface.

A hydraulic pressure control valve comprising:

• a cylindrical casing having a plurality of first lands formed on its inner circumferential surface at specified intervals and being in communication with a plurality of pressurized oil destinations, and a groove formed between each of said lands, alternate grooves being in communication with a high pressure source;
• and
• a valve body rotatably disposed in said casing and having additional lands of the same number as said first lands and formed on the peripheral surface of the valve body at specified intervals, the additional lands comprising second, third and fourth lands;
• said second lands being disposed in a circumferential direction opposite to said alternate grooves in communication with a high pressure source;
• said third lands being in communication with a low pressure source and disposed between alternate said second lands;
• said fourth lands being disposed in the remaining lands, between alternate said second lands, said fourth lands being disconnected from the low pressure source, and forming communicating portions between adjacent first lands of said casing via said fourth lands;
• and
• notches disposed at corners of one of said valve body and said casing, each notch including a first portion substantially parallel to one of the inner circumferential surface of said casing and the peripheral surface of said valve body, and a second portion having an axial sectional shape forming a circular arc and having a radius approximately equal to the radial depth from said one of said inner circumferential surface and the peripheral surface in said first portion, wherein said second portion links said first portion and said one of said inner circumferential surface or peripheral surface.

A hydraulic pressure control valve comprising:

• a cylindrical casing having a plurality of first grooves formed on its inner circumferential surface at specified intervals and being in communication with a plurality of pressurized oil destinations, and a land formed between each of said grooves, alternate lands being in communication with a high pressure source;
• and
• a valve body rotatably disposed in said casing and having additional grooves of the same number as said first grooves and formed on the peripheral surface of the valve body at specified intervals, the additional grooves comprising second, third and fourth grooves;
• said second grooves being disposed in a circumferential direction opposite to said alternate lands in communication with a high pressure source;
• said third grooves being in communication with a low pressure source and disposed between alternate said second grooves;
• said fourth grooves being disposed in the remaining grooves, between alternate said second grooves, said fourth grooves being disconnected from the low pressure source, and forming communicating portions between adjacent first grooves of said casing via said fourth grooves;
• and
• notches disposed at corners of one of said valve body and said casing, each notch including a first portion substantially parallel to one of the inner circumferential surface of said casing and the peripheral surface of said valve body, and a second portion having an axial sectional shape composed of at least one straight line closely approximating a circular arc and having a radius approximately equal to the radial depth from said one of said inner circumferential surface and the peripheral surface in said first portion, wherein said second portion links said first portion and said one of said inner circumferential surface or peripheral surface.

A hydraulic pressure control valve comprising:

• a cylindrical casing having a plurality of first lands formed on its inner circumferential surface at specified intervals and being in communication with a plurality of pressurized oil destinations, and a groove formed between each of said lands, alternate grooves being in communication with a high pressure source;
• and
• a valve body rotatably disposed in said casing and having additional lands of the same number as said first lands and formed on the peripheral surface of the valve body at specified intervals, the additional lands comprising second, third and fourth lands;
• said second lands being disposed in a circumferential direction opposite to said alternate grooves in communication with a high pressure source;
• said third lands being in communication with a low pressure source and disposed between alternate said second lands;
• said fourth lands being disposed in the remaining lands, between alternate said second lands, said fourth lands being disconnected from the low pressure source, and forming communicating portions between adjacent first lands of said casing via said fourth lands;
• and
• notches disposed at corners of one of said valve body and said casing, each notch including a first portion substantially parallel to one of the inner circumferential surface of said casing and the peripheral surface of said valve body, and a second portion having an axial sectional shape composed of at least one straight line closely approximating a circular arc and having a radius approximately equal to the radial depth from said one of said inner circumferential surface and the peripheral surface in said first portion, wherein said second portion links said first portion and said one of said inner circumferential surface or peripheral surface.