Lifting device

Abstract

A lifting device comprises an ejection seat, a base and two movable supporting frames between the ejection seat and the base, wherein the movable supporting frames comprise upper and lower lifting arms respectively hinged to the ejection seat and the base, and the sliding ends of the upper and lower lifting arms are in sliding connection with a middle frame upper chute through the same hinge pin. Upper and lower pull rods are respectively hinged to the upper and lower lifting arms and hinged to a middle frame through the same hinge pin, the upper and lower lifting arms and the upper and lower pull rods are symmetrically arranged on upper and lower sides of the middle frame, connecting lines formed by two hinge centers of the upper pull rods are parallel, the length is one half of the length of connecting lines of two-end hinge centers of the lower lifting arms, connecting lines formed by two hinge centers of the lower pull rods are parallel, the length is one half of the length of connecting lines of two-end hinge centers of the upper lifting arms. A driving device drives the upper and lower lifting arms in the movable supporting frames to move along a chute in the middle frame to achieve ejection seat lifting. Supporting separation distances of the lifting arms on the ejection seat are invariant, and required pushing force when the ejection seat is lifted from the lowest position is small.

Description

technical field [0001] The invention relates to a working platform or a lifting bed with a lifting function. Background technique [0002] In equipment that needs to be lifted, such as aerial work lifting platforms and medical beds, scissor-type lifting mechanisms are usually used to lift the work platforms or medical beds. Typical scissor-type lifting mechanisms are as follows: figure 1 As shown, it includes a platform 100, an underframe 200 and a lifting frame 300 between the two. The lifting frame 300 includes two connecting rods arranged in a cross-scissor structure. The two connecting rods are hinged at the middle intersection point, one of which is The upper end of the rod is hinged with the platform 100, the lower end is slidingly connected with the chute on the bottom frame 200, the upper end of the other connecting rod is slidably connected with the chute on the platform 100, and the lower end is hinged with the bottom frame 200, by horizontally pushing the lower pa...

AI Technical Summary

Problems solved by technology

[0002] In equipment that needs to be lifted, such as aerial work lifting platforms and medical beds, scissor-type lifting mechanisms are usually used to lift the work platforms or medical beds. Typical scissor-type lifting mechanisms are as follows: figure 1 As shown, it includes a platform 100, an underframe 200 and a lifting frame 300 between the two. The lifting frame 300 includes two connecting rods arranged in a cross-scissor structure. The two connecting rods are hinged at the middle intersection point, one of which is The upper end of the rod is hinged with the platform 100, the lower end is slidingly connected with the chute on the bottom frame 200, the upper end of the other connecting rod is slidably connected with the chute on the platform 100, and the lower end is hinged with the bottom frame 200, by horizontally pushing the lower part of the connecting rod The sliding end, the vertical push platform 100 or the inclined push link can all realize the lifting of the platform 100, such as the "mobile lifting loading and unloading platform" disclosed in Chinese patent CN2861115Y, and the "a scissor type hydraulic lifting platform with symmetrical oil cylinders" disclosed in CN202575867U. "All realize lifting by scissor lift mechanism, the defect of this traditional scissor lift mechanism is: first, see figure 1 , figure 2 , the support distance L between the two connecting rods will decrease as the platform 100 rises; secondly, if the lower sliding end of the connecting rod is pushed horizontally, when the platform rises from the lowest position, since the connecting rod The force on the hinged end of the upper part of the rod and the platform 100 that pushes the connecting rod up is the component force of the horizontal thrust in the length direction of the vertical connecting rod. Therefore, when the platform 100 rises from the lowest position, a larger thrust is required. ; If the platform is pushed vertically, the lifting range of the platform is limited due to the need to set up propellers such as electric push rods or oil cylinders in the vertical direction between the platform and the chassis; The problem of limited force and platform lifting range

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