JPS6399003U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, Fig. 2 is an enlarged view of the part in Fig. 1, Fig. 3 is an explanatory diagram of the configuration of a conventional descending speed control device, and Fig. 4 is an adjustment of the flow rate regulating valve. FIG. 5 is an explanatory diagram of the flow rate, FIG. 5 is an explanatory diagram of the flow of the flow rate regulating valve, and FIG. 6 is a free flow pressure loss characteristic diagram. 1, 2, and 3 are electromagnetic switching valves, 14 is a down control valve unit, 15, 16, and 17 are flow rate adjustment valves, 26 is a single-acting cylinder, 31 is a bypass path, and 32 is a check valve.

Claims (1)

[Scope of utility model registration request] A plurality of electromagnetic switching valves that are provided in the hydraulic circuit of the single-acting cylinder 26 and control the raising and lowering operations of the single-acting cylinder 26 by switching operations, and a pipe line between these electromagnetic switching valves and the single-acting cylinder 26. In a descending speed control device equipped with a plurality of flow rate regulating valves that flow each adjusted flow rate according to the required descending speed when the single-acting cylinder 26 descends, the plurality of flow regulating valves are housed in one unit and can be operated in-line. A cartridge-type pressure-insured down control valve unit 14 that can be used is configured, and a single-acting cylinder 2
A bypass path 31 is provided in which oil flows to the single-acting cylinder 26 side during the upward operation of the single-acting cylinder 26 without passing through the flow rate adjustment valve with at least the minimum adjusted flow rate. A descending speed control device characterized in that it is provided with a check valve 32 for closing the lowering speed.