JPH0323201U

JPH0323201U -

Info

Publication number: JPH0323201U
Application number: JP8389089U
Authority: JP
Priority date: 1989-07-17
Filing date: 1989-07-17
Publication date: 1991-03-11

Description

[Brief explanation of drawings]

第１図は本考案の一実施例であるエア圧低下防
止回路を備えたエア回路の一例を示す回路図であ
る。第２図〜第４図はそれぞれ第１図のエア回路
の異なる作動状態を示す回路図で、第２図はピス
トンロツドの引込み過程であり、第３図はピスト
ンロツドが完全に引き込まれた状態であり、第４
図はピストンロツドの突出し過程である。１０…エアシリンダ、１２…ピストン、１４ａ
，１４ｂ…圧力室、１８…圧力エア供給源、２２
…切換弁、２８…シヤツトル弁、３０ａ，３０ｂ
…流入ポート、３２…出口ポート、３４…配管（
バイパス通路）、３８…逆止め弁、４０…エア圧
低下防止回路。 FIG. 1 is a circuit diagram showing an example of an air circuit equipped with an air pressure drop prevention circuit according to an embodiment of the present invention. Figures 2 to 4 are circuit diagrams showing different operating states of the air circuit in Figure 1. Figure 2 shows the piston rod being retracted, and Figure 3 shows the piston rod being fully retracted. , 4th
The figure shows the protrusion process of the piston rod. 10...Air cylinder, 12...Piston, 14a
, 14b...pressure chamber, 18...pressure air supply source, 22
...Switching valve, 28...Shuttle valve, 30a, 30b
...Inflow port, 32...Outlet port, 34...Piping (
bypass passage), 38... check valve, 40... air pressure drop prevention circuit.

Claims

[Claims for Utility Model Registration] A double-acting air cylinder that reciprocates a piston by selectively supplying pressure air from a pressure air supply source into a pair of pressure chambers, and the air cylinder and the pressure air supply. a first supply state in which the pressure air is supplied to one of the pair of pressure chambers and the other pressure chamber is opened to the atmosphere, and the pressure air is supplied to the other of the pair of pressure chambers; and a switching valve selectively switched to a second supply state in which one of the pressure chambers is opened to the atmosphere, and a cutoff state in which the supply of the pressure air is cut off and each of the pair of pressure chambers is kept airtight. When the switching valve is placed in the first or second supply state, the piston of the air cylinder is moved to the respective moving end, and when the switching valve is placed in the blocking state, the piston is prevented from moving and the switching valve is placed in the first or second supply state. In the air circuit held at the moving end, the circuit prevents the air pressure in the pressure chamber from decreasing in the cut-off state, wherein a pair of inflow ports are respectively connected to the pair of pressure chambers, and a pair of inflow ports are respectively connected to the pair of pressure chambers. a shuttle valve in which a high-pressure side inflow port among the ports communicates with an outlet port; a bypass passage provided in parallel with the switching valve and connecting the outlet port of the shuttle valve with the pressure air supply source; and the bypass passage. A check valve provided in the passage and allowing pressure air to flow in a direction from the pressure air supply source toward the shuttle valve, but blocking the flow of pressure air in the opposite direction. Cylinder air pressure drop prevention circuit.