CN210911918U

CN210911918U - Novel combined type trailer arm couple

Info

Publication number: CN210911918U
Application number: CN201921808895.6U
Authority: CN
Inventors: 金金
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-10-25
Filing date: 2019-10-25
Publication date: 2020-07-03
Anticipated expiration: 2029-10-25

Abstract

The utility model discloses a novel combined type trailer arm hook, which relates to the technical field of vehicle traction devices and comprises a height-adjusting suspension arm arranged on a vehicle body, wherein a traction base is arranged on the height-adjusting suspension arm, the height-adjusting suspension arm comprises a connecting part and a height-adjusting part which are arranged vertically, the connecting part is movably provided with a positioning block matched with the vehicle body near the two sides of the tail part, a first telescopic mechanism for driving the positioning block to stretch is arranged on the connecting part, the height-adjusting part is movably clamped on the traction base, the two sides of the height-adjusting part are provided with guide convex strips along the length direction of the height-adjusting part, a guide groove is arranged on the traction base, the outer end surface of the height-adjusting part is provided with a ladder-shaped clamping groove side by side along the length direction of the height-adjusting part, the back of the traction base is provided with a positioning block for positioning the traction base on, the positioning block is connected with a second telescopic mechanism used for driving the positioning block to stretch, and the positioning block has the advantages of convenience in use and high safety performance.

Description

Novel combined type trailer arm couple

Technical Field

The utility model relates to a vehicle traction device technical field especially relates to a novel combined type trailer arm couple.

Background

The existing trailer arm hook generally comprises a trailer arm body and a trailer ball head connected to the trailer arm body, wherein the trailer arm body is usually installed on a towing vehicle, and the trailer ball head is usually connected to a towed vehicle such as a trailer, a fault vehicle and the like, and is mainly used for connecting and towing the trailer, the fault vehicle and other towed and carried objects. But the current trailer arm couple has the function singleness, can't adjust the problem of tractive height, seriously influences the convenience in the normal use like this.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome not enough among the prior art, provide a novel combined type trailer arm couple, through the tractive base that the components of a whole that can function independently set up, heighten the linkage, make it conveniently adjust the tractive height, possess convenient to use, advantage that the security performance is high.

In order to realize the purpose, the utility model adopts the following technical proposal; a novel combined trailer arm hook comprises a height-adjusting suspension arm arranged on a trailer body, wherein a traction base is arranged on the height-adjusting suspension arm, the heightening suspension arm comprises a connecting part and a heightening part which are vertically arranged, a first positioning block matched with the vehicle body is movably arranged at the position of the connecting part close to the two sides of the tail part, the connecting part is provided with a first telescopic mechanism for driving the first positioning block to stretch, the height adjusting part is movably clamped on the traction base, the two sides of the height-adjusting part are provided with guide protruding strips along the length direction of the height-adjusting part, the traction base is provided with guide grooves matched with the guide protruding strips, the outer end face of the height-adjusting part is provided with stepped clamping grooves in parallel along the length direction of the height-adjusting part, a positioning ejector block used for positioning the traction base on the height-adjusting part is arranged on the back of the traction base corresponding to the clamping grooves, and the positioning ejector block is connected with a second telescopic mechanism used for driving the positioning ejector block to stretch.

In order to further optimize the utility model discloses, can prefer following technical scheme for use:

preferably, the front portion is provided with the decorative body on the tractive base, transversely offer the tractive hole that is used for connecting the shackle on the decorative body, tractive base top is provided with the mounting groove one that is used for installing the ball-type towing pintle, tractive base back has been seted up to the preceding pinhole one of wearing by the back, wear to be equipped with the fixed pin that is used for fixed ball-type towing pintle in the pinhole one.

Preferably, a hanging groove used for hanging the decoration panel is formed in the front end of the traction base, a second mounting groove used for mounting the spherical towing hook is formed in the top of the traction base, a second through pin hole is formed in the back of the traction base in a penetrating mode from back to front, a fixing bolt used for fixing the spherical towing hook and the decoration panel penetrates through the second through pin hole, and the front end of the fixing bolt penetrates through the second mounting groove and extends out of the traction base.

Preferably, the clamping grooves are formed by a plurality of angle-shaped protruding strips which are arranged side by side, and a plurality of positioning teeth matched with the clamping grooves are arranged on the positioning ejector block.

Preferably, the cross section of the angle-shaped protrusion is a right triangle, and drainage grooves are formed in the height adjusting part corresponding to the two sides of the angle-shaped protrusion.

Preferably, the height adjusting part is provided with a limit stop corresponding to the bottom of the stepped clamping groove for preventing the height adjusting part from being separated from the traction base.

Preferably, telescopic machanism one includes lock core, gangbar, column kicking block, the installation blind hole has been seted up along connecting portion length direction correspondence height-adjusting portion top position on the connecting portion, installation blind hole bottom extends to a locating piece position department, the gangbar inlays the dress in the installation blind hole, the lock core sets up in gangbar outside one end position, the column kicking block sets up in the inboard one end position of gangbar, set up on the locating piece one and rotate the rotation draw-in groove of being connected with the column kicking block.

Preferably, the first positioning block comprises a left positioning block and a right positioning block which are arranged in a central symmetry manner, cylindrical bosses matched with the vehicle body are arranged on the outer side end faces of the left positioning block and the right positioning block, the rotary clamping grooves on the left positioning block and the right positioning block comprise square through grooves and semicircular grooves, and two semicircular grooves are symmetrically arranged on two sides of each square through groove.

Preferably, the telescopic mechanism two includes drive shaft, expanding spring one, regulating arm one, adjust knob one, the drive shaft sets up in the tractive base along the flexible direction activity of fixture block, expanding spring one inlays the dress and sets up and deviates from fixture block one end in the drive shaft, regulating arm one radially sets up on the tractive base along the drive shaft, regulating arm one end off-centre is provided with column kicking block two, it is provided with U type spout to correspond column kicking block two positions on the drive shaft lateral wall, drive shaft and one rotation of regulating arm are connected, adjust knob one clamps the setting and deviates from drive shaft one end on regulating arm one.

Preferably, still be provided with the locking mechanism who is used for locking the drive shaft on the tractive base relative to an adjustment knob opposite side, locking mechanism includes spacing pull rod, adjust knob two, expanding spring two, spacing pull rod radially sets up on the tractive base along the drive shaft, spacing pull rod is close to drive shaft one end and is provided with the column kicking block, the spacing groove has been seted up corresponding column kicking block position on the drive shaft lateral wall, adjust knob two clamps the setting and deviates from drive shaft one end on adjust arm two, two suit settings of expanding spring are used for the outside pull back of spacing pull rod to reset on spacing pull rod.

The utility model has the advantages that:

1. the utility model utilizes the height-adjusting suspension arm and the traction base which are connected in a split type to adjust the height, thereby solving the problems of non-adjustable height and single function of the existing trailer arm hook and further improving the use convenience of the equipment; the step-type buckle structure is adopted in the heightening part in the equipment, on one hand, the step-type clamping groove is adopted to have a multi-stage heightening function, meanwhile, the adjustable range and the adjustable step pitch are wider, and the application condition of the equipment is further improved. On the other hand and cascaded draw-in groove complex location kicking block, it adopts polylith location tooth to constitute, and the firm in connection nature of block position department has been guaranteed more to the area of contact between location tooth and the cascaded draw-in groove.

2. The utility model discloses install telescopic machanism one, telescopic machanism two on trailer arm couple, conveniently improve through telescopic machanism and heighten the firm in connection between suspension arm and the automobile body, the corresponding drive shaft in telescopic machanism two deviates from fixture block one end and installs telescopic spring one simultaneously, facilitates the connection compactness between fixture block and the draw-in groove; in the utility model, the water drainage grooves are arranged on the two sides of the corresponding angle-shaped bulge on the height adjusting part, which is favorable for fast water guiding and dirt removal in severe environment and ensures the smooth operation of the adjusting mechanism; the utility model is provided with a mounting groove for mounting the spherical hook at the top of the traction base, which is convenient for extending the functionality of the trailer arm hook through the spherical hook; furthermore, an adjusting knob I and an adjusting knob II are symmetrically arranged on two sides of the traction base, so that the attractiveness of the equipment is improved.

Drawings

FIG. 1 is a schematic perspective view of a composite trailer arm hitch in example 1;

FIG. 2 is a side view of the composite trailer arm hitch of example 1;

FIG. 3 is a front view of the composite trailer arm hitch of embodiment 1;

FIG. 4 is a top view of the composite trailer arm hitch of example 1;

FIG. 5 is a schematic view showing the structure of a pulling base in example 1;

FIG. 6 is a schematic perspective view of the height-adjustable suspension arm;

FIG. 7 is a schematic view of the internal structure of the height-adjustable suspension arm;

FIG. 8 is a schematic structural view of the telescoping mechanism;

FIG. 9 is a schematic view of a linkage rod;

FIG. 10 is a schematic view of a positioning block;

FIG. 11 is a schematic view of the second telescopic mechanism in use;

FIG. 12 is a schematic structural view of a second telescoping mechanism;

FIG. 13 is a schematic view of an adjustment arm;

FIG. 14 is a perspective view of the composite trailer arm hitch of embodiment 2;

FIG. 15 is a side view of the composite trailer arm hitch of embodiment 2;

FIG. 16 is a top view of the composite trailer arm of embodiment 2;

FIG. 17 is a schematic view showing a structure of a pulling base in example 2;

wherein: 1-a drawing base, 2-a composite trailer arm, 3-a first installation groove, 4-a connecting part, 5-an elevation adjusting part, 6-an elastic positioning mechanism, 7-a side positioning mechanism, 8-a guide raised strip, 9-a guide groove, 10-a drawing hole, 11-a fixed pin, 12-a limiting groove, 13-a positioning top block, 14-a step-shaped clamping groove, 15-a cover plate, 16-a fixed bolt, 17-a hanging groove, 18-a drainage groove, 19-a limiting baffle, 20-an angle-shaped bulge, 21-a positioning tooth, 22-a positioning plate, 23-a first expansion mechanism, 24-a locking mechanism, 25-a second expansion mechanism, 26-a second installation groove, 101-a lock cylinder, 102-a linkage rod, 103-a sliding groove and 104-a left positioning block, 105-right positioning block, 106-fixing base, 107-mandril, 108-square through groove, 109-semicircular groove, 110-column top block I, 201-driving shaft, 202-expansion spring I, 203-adjusting arm I, 204-adjusting knob I, 205-adjusting knob II, 206-expansion spring II, 207-limiting pull rod, 208-anti-skid pattern, 209-U-shaped sliding groove and 210-column top block II.

Detailed Description

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Example 1

As shown in fig. 1-13, a novel combined type trailer arm couple, hang arm 2 including installing the accent height on the automobile body, the accent height is hung and is installed tractive base 1 on the arm 2, the anterior mount has the decorative body on tractive base 1, the decorative body is a shark head shape, transversely offer the tractive hole 10 that is used for connecting the shackle on the decorative body, tractive base top is installed and is used for installing mounting groove one 3 of ball-type tow hook, tractive base back has seted up to wear pinhole one from the back before by, wear to be equipped with the fixed pin 11 that is used for fixed ball-type tow hook in wearing pinhole one, wear pinhole one to be the counter bore, guarantee that the fixed pin puts into the counter bore and prevents outer the hourglass, the fixed pin afterbody still installs the pull ring, be convenient for take out the fixed. The height-adjusting suspension arm comprises a connecting part 4 and a height-adjusting part 5 which are vertically arranged, and a reinforcing rib plate is arranged at the connecting position between the connecting part and the height-adjusting part to ensure the structural strength of the connecting position; the automobile locking device comprises a connecting part, a first positioning block and a first columnar ejecting block, wherein the first positioning block is movably installed at the positions, close to the two sides of the tail part, of the connecting part, the first positioning block is matched with a square standard jack on an automobile body, a first telescoping mechanism 23 used for driving the positioning block to stretch is installed on the connecting part, the first telescoping mechanism 23 comprises a lock cylinder 101, a linkage rod 102 and a first columnar ejecting block 110, a blind installation hole is formed in the top of the corresponding height-adjusting part of the connecting part in the length direction of the connecting part, the bottom of the blind installation hole extends to the position of the first positioning block, the linkage rod 102 is embedded in the blind installation hole, the lock cylinder is installed at one end of the outer side of the linkage rod, a cover plate 15 is hinged to the position, corresponding to the lock cylinder, of a height-adjusting suspension arm is provided with the cover plate, The outer side end faces of a right positioning block 105, a left positioning block 104 and a right positioning block 105 are provided with cylindrical bosses matched with a vehicle body, rotary clamping grooves on the left positioning block and the right positioning block comprise square through grooves 108 and semi-circular grooves 109, the semi-circular grooves are symmetrically arranged at two sides of the square through grooves, when the left positioning block and the right positioning block extend out, a columnar top block is clamped in a U-shaped accommodating space formed by the square through grooves and the semi-circular grooves, when the left positioning block and the right positioning block shrink, the columnar top block is clamped in a circular accommodating space formed by the semi-circular grooves and the semi-circular grooves, a linkage rod is enabled to rotate for a certain angle under the action of a lock core to drive the left positioning block and the right positioning block to extend out and shrink, and further the first positioning block is matched with a standard square hole on the vehicle body, the left positioning block and the right positioning block, meanwhile, the square through groove and the semicircular groove are formed in the outer side walls of the left positioning block and the right positioning block, so that the strength of the telescopic positioning block is guaranteed on the basis of realizing the telescopic function.

In order to further ensure the connection stability of the trailer arm hook, two elastic positioning mechanisms are arranged on the upper end face of the connecting part, the elastic positioning mechanisms adopt the existing commonly used downward-pressing type marbles, the height-adjusting part is movably clamped on the traction base, the two sides of the height-adjusting part are provided with guide protruding strips 8 along the length direction of the height-adjusting part, the traction base is provided with guide grooves 9 matched with the guide protruding strips 8, the accuracy of the moving process is ensured by matching the guide grooves 9 with the guide protruding strips, meanwhile, the sliding stability of the height-adjusting suspension arm can be ensured by the symmetrically arranged guide mechanisms, and the condition that the height-adjusting suspension arm deflects in the sliding process is prevented; increase outside terminal surface of portion and install echelonment draw-in groove 14 side by side along increasing a length direction, the corresponding draw-in groove position in tractive base back is installed and is used for being located the location kicking block 13 on increasing a portion with the tractive base, the draw-in groove is the protruding 20 formation of a plurality of angle types of arranging side by side, location kicking block 13 includes locating plate 22, install a plurality ofly on the locating plate 22 with draw-in groove complex location tooth 21, the protruding 20 cross section of angle type is right triangle, adopt cascaded buckle structure, the buckle area of cascaded buckle has greatly guaranteed the fastness and the security of buckle connection on the one hand, the increase interval of cascaded buckle is limited less simultaneously, but the height-adjusting scope is wider, equipment application condition has further been improved. The water draining grooves 18 are formed in the height adjusting part corresponding to the two sides of the angle-shaped protrusions, so that water can be quickly drained and decontaminated in a severe environment, and smooth operation of the adjusting mechanism is guaranteed. The positioning ejector block 13 is connected with a second telescopic mechanism 25 for driving the positioning block to stretch, the second telescopic mechanism 25 comprises a driving shaft 201, a first telescopic spring 202, a first adjusting arm 203 and a first adjusting knob 204, the driving shaft is movably installed in the drawing base along the stretching direction of the clamping block, the first telescopic spring is embedded and installed at one end, deviating from the clamping block, of the driving shaft, the first adjusting arm is installed on the drawing base along the radial direction of the driving shaft, one end of the second cylindrical ejector block 210 is eccentrically installed at one end of the adjusting arm, a U-shaped sliding groove 209 is installed on the outer side wall of the driving shaft, corresponding to the second cylindrical ejector block 210, the driving shaft is rotatably connected with the first adjusting arm, the first adjusting knob is installed at one end, deviating from the driving shaft, a locking mechanism 24 for locking the driving shaft is further installed at the other side of the first adjusting, spacing pull rod 207 radially installs on the tractive base along the drive shaft, spacing pull rod is close to drive shaft one end and installs the column kicking block, it has seted up spacing groove 12 to correspond the column kicking block position on the drive shaft lateral wall, adjust knob two clamps to install and deviates from drive shaft one end on adjusting arm two, expanding spring suit is installed and is used for the spacing pull rod to draw the back outward and reset on spacing pull rod, for the ease of operating personnel use, at adjust knob one, laid anti-skidding line 208 on the lateral wall of adjust knob two. The wing-shaped adjusting knob I and the wing-shaped adjusting knob II are matched with the shark head-shaped decorative body, so that the simulation design of the shark shape can be realized, and the appearance is more attractive and luxurious.

A limiting stop 19 for preventing the height adjusting part from being separated from the traction base is arranged on the height adjusting part corresponding to the bottom of the stepped clamping groove, when the positioning ejector block is contracted and separated from the clamping groove under the action of the second telescopic mechanism, the outer leakage height of the positioning ejector block is not lower than the position of the limiting stop 19, the traction base is limited by the positioning ejector block, a secondary processing limiting boss is not needed on the height adjusting suspension arm, and the processing cost is reduced; meanwhile, the height-adjustable suspension arm is prevented from sliding from top to bottom and being taken out of the traction base, and the falling and separation are prevented; further in order to ensure the safety of the trailer arm hook, a limiting groove is formed in the back of the drawing base, a side positioning mechanism 7 is arranged on one side of the heightening part corresponding to the limiting groove, the side positioning mechanism 7 comprises a fixed seat 106, a spring and a top ball are sequentially arranged in the fixed seat 106 from bottom to top, a top rod 107 is arranged in the fixed seat and corresponds to the position under the top ball, the bottom of the top rod 107 penetrates through the fixed seat to extend out and be supported on the linkage rod, a sliding groove 103 is formed in the linkage rod and corresponds to the position of the top rod in the circumferential direction of the linkage rod, the depth of the sliding groove 103 is linearly changed, the top ball is enabled to be lifted by the top rod under the driving of a first telescopic mechanism, when the first positioning block extends out, the top ball cannot fall down, the heightening suspension arm is enabled not to slide and be taken out from; when the positioning block contracts, the ejector rod is separated from the ejection bead and does not exert ejection force any more, and the ejection bead can contract inwards when being under certain pressure, so that the lifting suspension arm can be conveniently taken out from the traction base in a sliding manner from bottom to top.

Example 2

As shown in fig. 6-17, a novel composite trailer arm hook of this embodiment is different from embodiment 1 in that the structure of the pulling base portion is different, and the structure of the height-adjustable suspension arm portion is the same as that in embodiment 1, and is not repeated herein, and the structure of the pulling base portion is mainly described below; the front end of the traction base is provided with a hanging groove 16 for hanging a decorative panel, and the decorative panel can be designed in a customized manner according to customer requirements, so that more customer requirements are met; the top of the traction base is provided with a second mounting groove 26 for mounting the spherical towing hook, the back of the traction base is provided with a second through hole in a penetrating manner from back to front, a fixing bolt 17 for fixing the spherical towing hook and the decoration panel is arranged in the second through hole in a penetrating manner, the front end of the fixing bolt 17 penetrates through the second mounting groove and extends out of the traction base, the spherical towing hook is mounted in the second mounting groove, and the fixing bolt penetrates through the spherical towing hook from the inside to fix the spherical towing hook; the screw thread has been laid to the fixing bolt front end, is connected through screw thread and decoration panel, guarantees that the decoration panel can prevent to drop under the dual fastening of hanging dress groove 17 and fixing bolt.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and variations can be made in the embodiments or in part of the technical features of the embodiments without departing from the spirit and the scope of the invention.

Claims

1. The utility model provides a novel combined type trailer arm couple, hangs the arm including setting up the accent height on the automobile body, the accent height is hung and is provided with tractive base, its characterized in that on the arm: the height-adjusting suspension arm comprises a connecting portion and a height-adjusting portion, the connecting portion are arranged perpendicular to each other, a first positioning block matched with a vehicle body is movably arranged at positions, close to two sides of the tail, of the connecting portion, a first telescopic mechanism used for driving the first positioning block to stretch is arranged on the connecting portion, the height-adjusting portion is movably clamped on the drawing base, guide protruding strips are arranged on two sides of the height-adjusting portion along the length direction of the height-adjusting portion, guide grooves matched with the guide protruding strips are formed in the drawing base, stepped clamping grooves are formed in the outer end face of the height-adjusting portion along the length direction of the height-adjusting portion side by side, positioning ejector blocks used for positioning the drawing base on the height-adjusting portion are arranged in positions corresponding to the clamping grooves in the back of the drawing base, and the positioning ejector blocks are connected with a second.

2. The novel composite trailer arm hitch of claim 1, further comprising: the front portion is provided with the decorative body on the tractive base, transversely set up the tractive hole that is used for connecting the shackle on the decorative body, tractive base top is provided with the mounting groove one that is used for installing the ball-type towing pintle, tractive base back has been seted up to preceding by the back and has worn pinhole one, wear to be equipped with the fixed pin that is used for fixed ball-type towing pintle in the pinhole one.

3. The novel composite trailer arm hitch of claim 1, further comprising: the front end of the traction base is provided with a hanging groove used for hanging a decorative panel, the top of the traction base is provided with a second mounting groove used for mounting a spherical towing hook, the back of the traction base is provided with a second through hole in a penetrating manner from back to front, a fixing bolt used for fixing the spherical towing hook and the decorative panel is arranged in the second through hole in a penetrating manner, and the front end of the fixing bolt penetrates through the second mounting groove and extends out of the traction base.

4. The novel composite trailer arm hitch of claim 1, further comprising: the draw-in groove is a plurality of protruding strip formation of angle type of arranging side by side, be provided with a plurality of and draw-in groove complex location tooth on the location kicking block.

5. The novel composite trailer arm hitch of claim 4, further comprising: the cross section of the angle-shaped bulge is a right triangle, and drainage grooves are formed in the height adjusting part corresponding to the two sides of the angle-shaped bulge.

6. The novel composite trailer arm hitch of claim 1, further comprising: and a limiting stopper used for preventing the height adjusting part from being separated from the traction base is arranged on the height adjusting part corresponding to the bottom of the stepped clamping groove.

7. The novel composite trailer arm hitch of claim 1, further comprising: one telescopic machanism includes lock core, gangbar, column kicking block, the installation blind hole has been seted up along connecting portion length direction correspondence height-adjusting portion top position on the connecting portion, installation blind hole bottom extends to a locating piece position department, the gangbar inlays the dress in the installation blind hole, the lock core sets up in gangbar outside one end position, the column kicking block sets up in the inboard one end position of gangbar, set up on the locating piece one and rotate the rotation draw-in groove of being connected with the column kicking block.

8. The novel composite trailer arm hitch of claim 7, further comprising: the positioning block I comprises a left positioning block and a right positioning block which are arranged in a central symmetry manner, cylindrical bosses matched with a vehicle body are arranged on the outer side end faces of the left positioning block and the right positioning block, the rotary clamping grooves in the left positioning block and the right positioning block comprise square through grooves and semicircular grooves, and two semicircular grooves are symmetrically arranged on two sides of each square through groove.

9. The novel composite trailer arm hitch of claim 1, further comprising: the telescopic mechanism II comprises a driving shaft, a first telescopic spring, a first adjusting arm and a first adjusting knob, the driving shaft is movably arranged in the traction base along the telescopic direction of the clamping block, the first telescopic spring is embedded and arranged at one end, deviating from the clamping block, of the driving shaft, the first adjusting arm is radially arranged on the traction base along the driving shaft, one end of the adjusting arm is eccentrically provided with a second columnar ejecting block, a U-shaped sliding groove is formed in the outer side wall of the driving shaft corresponding to the second position of the second columnar ejecting block, the driving shaft is rotatably connected with the first adjusting arm, and the first adjusting knob is clamped and arranged at one end, deviating from the first driving shaft, of the.

10. The novel composite trailer arm hitch of claim 9, further comprising: the utility model discloses a traction base, including traction base, adjusting knob, telescopic spring, limiting pull rod, adjusting knob, spacing pull rod, adjusting knob, telescopic spring, the last relative adjusting knob opposite side of traction base still is provided with the locking mechanical system who is used for locking the drive shaft, locking mechanical system includes spacing pull rod, adjusting knob two, telescopic spring two, spacing pull rod radially sets up on the traction base along the drive shaft, spacing pull rod is close to drive shaft one end and is provided with the column kicking block, the spacing groove has been seted up to corresponding column kicking block position on the drive shaft lateral wall, adjusting knob two clamp the setting and deviate from drive shaft one end on adjusting arm two, two suit settings of.