JPH048855U

JPH048855U -

Info

Publication number: JPH048855U
Application number: JP4980890U
Authority: JP
Priority date: 1990-05-11
Filing date: 1990-05-11
Publication date: 1992-01-27

Description

[Brief explanation of drawings]

第１図は本考案の実施例を示す断面図、第２図
は従来例を示す断面図である。３０……ケース、３０ａ……上壁、３１……嵌
合孔、３１ａ……上部シリンダ孔、３１ｂ……リ
テーナ嵌合孔、３２……ピストンリテーナ、３２
ａ……下部シリンダ孔、３２ｂ……底壁、３３…
…止めリング、３４〜３６……第１〜第３ピスト
ン、３７〜４０……第１〜第４油室、４１……ス
テム、４２……上部リターンスプリング、４３…
…下部リターンスプリング、４４〜４７……第１
〜第４連通孔、４８〜５０……制御油路、５１…
…ドレン油路。 FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional example. 30... Case, 30a... Upper wall, 31... Fitting hole, 31a... Upper cylinder hole, 31b... Retainer fitting hole, 32... Piston retainer, 32
a...lower cylinder hole, 32b...bottom wall, 33...
... Retaining ring, 34-36... First to third piston, 37-40... First to fourth oil chamber, 41... Stem, 42... Upper return spring, 43...
...lower return spring, 44-47...first
~4th communication hole, 48-50...control oil passage, 51...
...Drain oil path.

Claims

[Scope of utility model registration request]

A small-diameter upper cylinder hole is formed in the upper end of the case, which has a closed top surface and an open bottom surface, and a large-diameter retainer fitting hole is formed in the remainder, and the retainer fitting hole has an open top surface and a closed bottom surface. A bottomed cylindrical piston retainer is fitted, the inner diameter of the cylinder part of the piston retainer is smaller than the inner diameter of the upper cylinder hole, and the lower cylinder hole is equal in diameter in the vertical direction, and the first piston is inserted into the upper cylinder hole. The second and third pistons are fitted vertically apart in the lower cylinder hole to divide the inside of the case into first to fourth oil chambers, and the first piston and the second piston are integrally connected to each other. A stem is provided that slidably penetrates the upper wall of the case and the axial center portions of the first and second pistons and is connected to the third piston, and a return spring that presses each piston downward is provided. A hydraulic servo mechanism, characterized in that a control oil path for selectively supplying hydraulic oil is connected to an oil chamber, a second oil chamber, and a fourth oil chamber, and a drain oil path is connected to a third oil chamber.