B6050型牛头刨床滑枕背部锁紧机构如图1所示。当需要松开锁紧螺母逆时针扳动锁紧螺母上的手柄(图中未画出)时,往往易于出现双头螺柱下端与连接叉松开、而上端倒反而不松开的现象。 B665等牛头刨床工作台与其前支架连接处也有类似情况。如图2所示,当需要松开前支架转动螺母时,往往易于出现双头螺柱随螺母转的现象。出现这些现象的原因,在于双头螺柱两端为等径、等螺距螺纹,螺旋升角相同、摩擦阻力相同,故使双头螺柱两端都有松开的可能。为此,我们将双头螺柱固定端改成细牙螺纹,经常需要松开的一端则用普通粗牙螺纹。如图1中的双头螺柱上端取M22(螺距t=2.5),下端取M22×1(t=1)。由于细牙螺纹自锁性 B6050 shaper ram back locking mechanism shown in Figure 1. When you need to loosen the lock nut and turn the handle (not shown) on the lock nut counterclockwise, it is easy to cause the lower end of the stud bolt to unfastened with the connecting fork while the upper end inverts without loosening. B665 and other shaper workbench with its front bracket connection at a similar situation. As shown in Figure 2, when the need to loosen the front bracket rotating nut, tend to tend to double stud with the nut turn phenomenon. The reason for these phenomena is that the studs have the same diameter at both ends, the same helical pitch, the same helix angle, and the same frictional resistance, so that studs may be loosened at both ends. To this end, we will double stud fixed ends into fine thread, often need to loose the end of the ordinary coarse thread. Take the upper end of the stud stud as M22 (pitch t = 2.5) in FIG. 1, and take M22 × 1 (t = 1) at the lower end. Due to fine thread self-locking