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CN-115042859-B - Articulated frame steering mechanism and engineering machinery

CN115042859BCN 115042859 BCN115042859 BCN 115042859BCN-115042859-B

Abstract

The invention relates to a steering mechanism, in order to solve the problem that the steering limit buffering effect on front and rear frames is poor by installing an elastic collision buffer device in the existing steering mechanism of an articulated frame, the invention constructs the steering mechanism of the articulated frame and engineering machinery, and a steering oil cylinder in the steering mechanism is provided with an annular buffer oil duct and a buffer sleeve; the circumferential side surface of the buffer sleeve is sequentially provided with a variable section and an extension section from the head end to the tail end, the minimum section area of a fit clearance between the buffer sleeve and a cylinder cover is reduced along with the increment of the insertion depth of the variable section, the head end of the extension section is unchanged after being inserted, and the distance between AB points of rotation centers at two ends of an oil cylinder is greater than or equal to the distance between AB points when the tail end of the variable section is inserted into an annular buffer oil duct and is smaller than the distance between AB points when a piston is contacted with the cylinder cover when the front and rear frames are at the maximum rotation angle. According to the invention, the oil cylinder is used for buffering and decelerating, the elastic collision buffer device is used for limiting collision contact, so that the impact during steering is reduced, and the comfort is improved.

Inventors

  • GAO MINGQIAN
  • JIANG LINGLI
  • JIANG TUO
  • WANG YUN
  • WU ZONGCAI
  • LI ZEHUA
  • LI JUNJUN
  • Yi Lirui
  • WU FUJIE

Assignees

  • 柳州柳工液压件有限公司
  • 广西柳工机械股份有限公司

Dates

Publication Date
20260505
Application Date
20220722

Claims (10)

  1. 1. The steering mechanism of the articulated frame comprises a front frame and a rear frame which are articulated, steering cylinders which are respectively arranged at the left side and the right side of a frame articulated point, and elastic collision buffer devices which are arranged on the front frame and the rear frame and are used for limiting the maximum rotation angle of the front frame and the rear frame, wherein the rotation center points of the two ends of the steering cylinders, which are articulated with the front frame and the rear frame, are respectively a point A and a point B; the distance between the point A and the point B when the front frame and the rear frame relatively rotate to the maximum rotation angle is larger than or equal to the distance between the point A and the point B when the tail end of the variable section of the buffer sleeve is inserted into the annular buffer oil duct, and is smaller than the distance between the point A and the point B when the piston of the steering oil cylinder is contacted with the cylinder cover.
  2. 2. The articulated frame steering mechanism according to claim 1, wherein an inner hole wall surface on the cylinder cover, which is matched with the circumferential side surface of the buffer sleeve, is a cylindrical surface, the variable cross section of the circumferential side surface of the buffer sleeve is composed of a conical surface section and a chamfer section positioned at the head end of the conical surface section, and the extension section of the circumferential side surface of the buffer sleeve is a cylindrical surface with the diameter equal to or smaller than the diameter of the tail end of the conical surface section.
  3. 3. The articulated frame steering mechanism according to claim 1, wherein a limiting step for limiting the contact of the head end face of the buffer sleeve is arranged on the piston rod, the buffer sleeve is sleeved between the limiting step and the piston in a floating manner, a rod sleeve matching gap for oil circulation is arranged between the inner hole wall face of the buffer sleeve and the piston rod, a radial channel for radially communicating the rod sleeve matching gap with the small cavity is arranged at the tail end of the buffer sleeve, and the head end face of the buffer sleeve and the end face of the limiting step are mutually clung and matched planes.
  4. 4. The articulated frame steering mechanism according to claim 3, wherein a flow area adjusting oil passage for communicating the small cavity with the small cavity connecting oil port is provided on the cylinder head, and a throttle valve mounted by screw fitting is provided in the flow area adjusting oil passage.
  5. 5. The articulated bogie steering mechanism according to claim 3, wherein the piston rod is provided with a flow area adjusting oil duct for communicating a rod sleeve fit clearance with a small cavity connecting oil port, the flow area adjusting oil duct is L-shaped, a radial section outlet of the flow area adjusting oil duct is positioned on the cylindrical surface of the piston rod, an axial section outlet of the flow area adjusting oil duct is positioned on the end face of a limiting step, and a throttle valve installed through threaded fit is arranged in the radial section.
  6. 6. An articulated bogie steering mechanism according to claim 4 or 5, wherein a terminal annular groove is provided in communication with the radial channel and the sleeve fitting gap at a location of the piston rod cylindrical surface near the piston end face.
  7. 7. The articulated truck steering mechanism of claim 6, wherein the radial channel is formed by a plurality of radial notches provided in an end face of the elongated section of the cushion sheath.
  8. 8. The articulated truck steering mechanism of claim 6, wherein the radial passage is formed by a plurality of radial through holes provided in an end face of the elongated section of the cushion sheath proximate the distal end.
  9. 9. The articulated frame steering mechanism according to claim 4 or 5, wherein a head-end annular groove communicating with the flow area adjusting oil passage and the rod sleeve fit clearance is provided at a position of the piston rod cylindrical surface near the limit step end face.
  10. 10. A construction machine characterized by having an articulated bogie steering mechanism according to any one of claims 1 to 9.

Description

Articulated frame steering mechanism and engineering machinery Technical Field The present invention relates to a steering mechanism, and more particularly, to an articulated frame steering mechanism and an engineering machine. Background In the field of engineering machinery, some engineering machinery such as loaders, graders, and road rollers employ articulated frames. The articulated frame comprises a front frame and a rear frame which are articulated through a pin shaft. A steering oil cylinder is arranged on the left side and the right side of a hinge point of the front frame and the rear frame respectively, two ends of the steering oil cylinder are connected with the front frame and the rear frame respectively, and the front frame and the rear frame are driven to rotate around a pin shaft in a telescopic manner by the steering oil cylinder to realize steering of engineering machinery. In the conventional articulated frame steering mechanism, in order to avoid a violent collision between the front and rear frames when the front and rear frames are rotated to the maximum steering angle, an elastic collision buffer device is generally installed between the front and rear frames. The elastic member in the elastic collision buffer device is usually a rubber block, and the rubber block is easy to lose the buffer function due to excessive extrusion in use. In addition, in the elastic crash cushion, the elastic force is positively correlated with the compression degree of the rubber block, and the larger the compression degree is, the larger the elastic force is, and the larger the steering crash cushion acceleration is. In the steering process, at the steering stroke end point, as the steering angle increases, the steering collision buffer acceleration increases and reaches the maximum value at the end point, the collision intensity reaches the maximum, and a steering collision buffer acceleration curve with more comfortable collision deceleration effect is difficult to obtain by designing the elastic piece. Disclosure of Invention The invention aims to solve the technical problem that the existing articulated frame steering mechanism is poor in steering limit buffering effect on front and rear frames by arranging an elastic collision buffering device, and provides the articulated frame steering mechanism and engineering machinery, so that the limit buffering effect is improved. The invention provides a steering mechanism of an articulated frame, which comprises a front frame and a rear frame which are articulated, steering cylinders which are respectively arranged at the left side and the right side of an articulated point of the frame, and elastic collision buffer devices which are arranged on the front frame and the rear frame and are used for limiting the maximum rotation angle of the front frame and the rear frame, wherein the rotation center points of the two ends of the steering cylinders, which are articulated with the front frame and the rear frame, are respectively a point A and a point B, the steering mechanism is characterized in that the steering cylinders are provided with an annular buffer oil duct which is arranged between a cylinder cover and a piston rod and is communicated with a small cavity and a small cavity connecting oil port, a buffer sleeve which can be inserted into the annular buffer oil duct and is in clearance fit with the cylinder cover is sleeved on the piston rod, and the circumferential side surface of the buffer sleeve is sequentially provided with a variable section and an extension section from the head end to the tail end, the minimum section area of the fit clearance between the buffer sleeve and the cylinder cover is gradually decreased along with the insertion depth of the buffer sleeve, and the minimum section area of the fit clearance between the buffer sleeve and the buffer sleeve is not gradually changed along with the insertion depth of the buffer sleeve after the insertion of the head section is inserted into the extension section; the distance between the point A and the point B when the front frame and the rear frame relatively rotate to the maximum rotation angle is larger than or equal to the distance between the point A and the point B when the tail end of the variable section of the buffer sleeve is inserted into the annular buffer oil duct, and is smaller than the distance between the point A and the point B when the piston of the steering oil cylinder is contacted with the cylinder cover. In the invention, when the relative rotation angle of the front frame and the rear frame is close to the maximum rotation angle, the piston rod of the corresponding side steering oil cylinder extends out to the buffer sleeve to be inserted into the annular buffer oil duct, so that the flow area between the small cavity and the small cavity connecting oil port is reduced, the extending speed of the piston rod is reduced, and the hydraulic buffer is realized. Before the