JPS5899296U - Forklift hydraulic control system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional main part, Figures 2 to 5 show an embodiment of this invention, and Figure 2 is a first embodiment.
An enlarged cross-sectional view of the main part of one cylinder and a diagram showing the other cylinder connected symbolically, FIG. 3 is a connection diagram of the second embodiment, and FIG. 4 is a connection diagram of the third embodiment. FIG. 5 is a connection diagram of the fourth embodiment as well. 71.8...First cylinder, 9...Second cylinder, C...Control valve, 11
．． ss, 41... Valve body, 12... Curved valve body spool, 21° 37.63... Detection orifice, 30.35... Cylinder chamber, 31.5
4... Spring. Correction 1984. 3-24 The scope of claims for utility model registration is amended as follows. Scope of Claim for Utility Model Registration A plurality of first cylinders that are mechanically interlocked, and a second cylinder that is connected to each other so that it extends before the first cylinder when rising and contracts after the first cylinder when falling. In the hydraulic control device for controlling the descending speed of the cylinders, a down control valve is provided at or near the bottom of one of the first cylinders, and a down control valve is provided in the cylinder chamber of the other cylinder and the cylinder of the second cylinder. A chamber is connected to the down control valve, and a valve body is installed in the valve body of the control valve, and a detection orifice and a chair are formed in communication with the cylinder chamber of the one first cylinder. The differential pressure between the front and rear is introduced into the valve body, and the valve body moves against the spring according to the differential pressure to control the opening of the control orifice communicating with the switching valve.
Hydraulic pressure of a forklift configured to move the valve body and roll the control orifice by the fluid force when the oil in the cylinder chamber flows into the down control valve and flows out from the control orifice when the cylinder is lowered. Control device.

Claims (1)

[Scope of utility model registration request] It is equipped with a plurality of first cylinders that move mechanically, and a second cylinder that extends before the first cylinders when ascending and contracts after the first cylinders when descending, and controls the descending speed of these cylinders. In the hydraulic control device, a down control valve is provided at or near the bottom of one of the first cylinders, while a cylinder chamber of the other cylinder and a cylinder chamber of the second cylinder are communicated with the down control valve. , and this control valve includes a valve body inside the valve body, and also forms a detection orifice that communicates with the cylinder chamber of the one eleventh cylinder, and guides the differential pressure before and after the detection orifice to the valve body. In response to the pressure difference, the valve body moves against the spring to control the opening of the control orifice communicating with the switching valve, while oil in the cylinder chamber flows into the down control valve when the second cylinder descends. A hydraulic control device for a forklift truck, wherein the hydraulic control device for a forklift is configured to control a control orifice by moving the valve body by the force of fluid flowing out from the control orifice.