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一、速降阀的原理在推土机设计中,为了增大提升液压缸的下降速度,提高生产率,在缸的上、下腔之间采用了速降阀(图1)。这种阀的构造见图2。如图2所示,当提升液压缸刚开始下降时,由于薄壁小孔A、B 的节流作用,M 腔的压力大于N 腔的压力,克服弹簧1的推力,将阀4顶开,使缸小腔的回油全部进入大腔,从而大大提高了活塞的下降速度。同时,还可以减少由于推土铲重力作用活塞下降速度逐步增大时,在上腔产生的真空度。
First, the principle of rapid down valve In the bulldozer design, in order to increase the descending speed of the hydraulic cylinder, increase productivity, in the cylinder between the lower chamber using the drop valve (Figure 1). The construction of this valve is shown in Figure 2. As shown in FIG. 2, when the lift cylinder just starts to descend, due to the throttling effect of the thin-walled holes A and B, the pressure of the M cavity is greater than the pressure of the N cavity to overcome the thrust of the spring 1 to open the valve 4, So that a small cavity of the tank all the oil into the large cavity, which greatly increased the rate of decline of the piston. At the same time, it can also reduce the degree of vacuum generated in the upper chamber as the descending speed of the piston gradually increases due to the gravitational effect of the blade.