Coupler buffer device mounting structure with small-fastening-torque pushing under compact space

1 . A coupler buffer device mounting structure, comprising:

a double-headed stud passing through an installation fabrication hole of a vehicle body structure from a coupler side toward a vehicle body side, wherein the vehicle body side defines a cavity and wherein fastening operations cannot be performed on the vehicle body side;

a nut screwed on a first end of the double-headed stud;

a push nut screwed on a second end of the double-headed stud and provided with a plurality of axial screw holes in a circumferential direction; and

a plurality of push screws screwed into the plurality of axial screw holes of the push nut, wherein a coupler buffer device is clamped and fixed to the vehicle body structure by heads of the plurality of push screws abutting against the coupler buffer device via a hard washer, and wherein tightening the plurality of push screws from the coupler side generates a plurality of jacking forces that act directly on the hard washer to clamp and fix the coupler buffer device to the vehicle body structure.

2 . The coupler buffer device mounting structure according to claim 1 , wherein a toothed washer is arranged between the nut and the vehicle body structure.

3 . A method for dismounting a coupler buffer device of a rail vehicle in a closed space on a vehicle body side, by using the coupler buffer device mounting structure according to claim 2 , the method comprising the steps of:

step 1, suspending the coupler buffer device to ensure that the coupler buffer device does not fall off after a fastener is removed;

step 2, unscrewing the plurality of push screws from the coupler buffer device side by using a torque wrench to disengage the plurality of push screws from the hard washer;

step 3, manually unscrewing and removing the push nut;

step 4, unscrewing the double-headed stud and removing the double-headed stud, the nut and the toothed washer; and

step 5, dismounting and removing the coupler buffer device.

4 . The coupler buffer device mounting structure according to claim 2 , wherein the nut is integral with the toothed washer.

5 . A method for mounting a coupler buffer device of a rail vehicle in a closed space on a vehicle body side, wherein the operation of fixing by the coupler buffer device mounting structure according to claim 2 comprises the steps of:

step 1, lifting the coupler buffer device to a vehicle body installation position;

step 2, allowing the double-headed stud through the installation fabrication hole of the vehicle body structure and an installation hole of the coupler buffer device from a coupler side to a vehicle body side, and arranging the toothed washer between the nut and the vehicle body structure, and screwing the nut on the first end of the double-headed stud;

step 3, sleeving the hard washer on the second end of the double-headed stud from an outside, screwing the push nut on the second end of the double-headed stud,

on a coupler buffer device side, and then successively tightening the plurality of push screws from the coupler buffer device side, so that heads of the plurality of push screws abut against the hard washer, and the hard washer abuts against an outer end face of the coupler buffer device; and

step 4, checking that a clearance value between the hard washer and the push nut is within a predetermined clearance range and applying a witness mark indicating completion of tightening of the push nut.

6 . The method for mounting the coupler buffer device of the rail vehicle according to claim 5 , wherein each of the push screws are screwed by a torque wrench in step 3 , and a tightening torque is set to about 70 N. m for each push screw.

7 . The coupler buffer device mounting structure according to claim 1 , wherein a number of the plurality of push screws is six.

8 . The coupler buffer device mounting structure according to claim 1 , wherein the double-headed stud is pre-formed with a raised head on a coupler side.

9 . A rail vehicle having the coupler buffer device mounting structure according to claim 1 .

10 . The rail vehicle having the coupler buffer device mounting structure according to claim 9 , wherein in the coupler buffer device mounting structure, a toothed washer is arranged between the nut and the vehicle body structure.

11 . The rail vehicle having the coupler buffer device mounting structure according to claim 10 , wherein in the coupler buffer device mounting structure, the nut is integral with the toothed washer.

12 . The rail vehicle having the coupler buffer device mounting structure according to claim 9 , wherein in the coupler buffer device mounting structure, a number of the plurality of push screws is six.

13 . The rail vehicle having the coupler buffer device mounting structure according to claim 9 , wherein in the coupler buffer device mounting structure, the double- headed stud is pre-formed with a raised head on a coupler side.