JPH0222993U

JPH0222993U -

Info

Publication number: JPH0222993U
Application number: JP10047188U
Authority: JP
Priority date: 1988-07-27
Filing date: 1988-07-27
Publication date: 1990-02-15
Anticipated expiration: 2003-07-27
Also published as: JPH0645041Y2

Description

[Brief explanation of drawings]

第１図および第２図は、本考案の負荷検出手段
を備えた複動油圧シリンダの一実施を示し、第１
図は中間伸長状態を示す説明図、第２図は最伸長
直前の状態を示す説明図である。第３図〜第５図
は、夫々他の実施例の説明図である。シリンダ；１、ピストン；２、ピストンロツド
；３、ピストンロツド側油室；６、反ピストンロ
ツド側油室；７、給排油路；４，５、パイロツト
逆止弁；９、開閉弁；１１、ルーズな連結手段；
１６，１６′、負荷検出手段；１０。 1 and 2 show one implementation of a double-acting hydraulic cylinder equipped with load detection means of the present invention, the first
The figure is an explanatory diagram showing an intermediate expansion state, and FIG. 2 is an explanatory diagram showing a state immediately before maximum expansion. FIGS. 3 to 5 are explanatory diagrams of other embodiments, respectively. Cylinder; 1, Piston; 2, Piston rod; 3, Piston rod side oil chamber; 6, Opposite piston rod side oil chamber; 7, Oil supply and drain passage; 4, 5, Pilot check valve; 9, Open/close valve; 11, Loose connection means;
16, 16', load detection means; 10.

Claims

[Scope of utility model registration request]

A double acting device comprising a cylinder, a piston fitted into the cylinder in an oil-tight and slidable manner, and a piston rod whose base end is connected to the piston and whose tip extends out of the cylinder in an oil-tight and slidable manner. A hydraulic cylinder, in particular, its piston rod side oil chamber and anti-piston rod side oil chamber are respectively connected to a four-way three-position hydraulic switching valve via an oil supply/drainage path, and an oil supply/drainage path connected to the anti-piston rod side oil chamber. , the flow of hydraulic oil in the direction of the oil chamber on the side opposite to the piston rod is free, but the flow of hydraulic oil in the opposite direction occurs when the oil pressure in the oil supply and drainage passage connected to the oil chamber on the piston rod side exceeds a predetermined value. A load detection means is provided with a pilot check valve or a counterbalance valve that enables the double-acting hydraulic cylinder, and detects the load acting on the double-acting hydraulic cylinder using the pressure in at least the oil chamber on the side opposite to the piston rod as a detection medium. , on the downstream side of the pilot check valve or counterbalance valve, the hydraulic oil is always allowed to flow from the oil chamber on the side opposite to the piston rod toward the pilot check valve, and the hydraulic oil flows in the opposite direction. An on-off valve having an opening/closing function for the cylinder is installed, and the on-off valve is attached to the end of the cylinder opposite to the piston rod, and a double-acting valve is installed between the on-off valve and the piston and extends into the oil chamber on the side opposite to the piston rod. A double-acting hydraulic cylinder equipped with a load detection means, characterized in that the hydraulic cylinder is connected by a loose connection means that closes the on-off valve when the hydraulic cylinder is in the vicinity of its maximum extension state.