BENDIX SD-13-4958 사용자 설명서

See Figure 6.  

The first four rows of this table show normal vehicle braking 

where  the  PMV  does  not  intervene.    In  the  case  of  a 

rapid, non-antilock release of the brakes (e.g. if the driver 

releases the brakes after a severe brake application), the  

Bendix

®

 M-40QR

™  

PMV assists the quick release of the 

brakes by being the point at which the air is exhausted.

The final four rows of the table show the actions taken 

during an antilock braking event. 

If  equipped  with  a  Bendix

®

 EC-60

®

 (or later) advanced 

controller, following the completion of the second round 

of PMV & TCV Chuff Tests, the controller (if configured to 

do so) will perform a test to cross-check the trailer PMV 

operation with the vehicle stop lamps.  If the trailer PMV 

circuit is mis-wired (including the steer axle TCV), the PMV 

will exhaust a large amount of air, or none at all.

HF and QR De-energized De-energized

Air pressure supplied to the modulator exits 

the modulator delivery port and flows to the 

service brake chambers.

HF and QR De-energized De-energized

When the desired air pressure is attained in 

the service brake chambers, the air pressure 

in the system levels off.

HF and QR De-energized De-energized

Air from the brake chambers moves back 

through the modulator in the reverse 

direction  as  it  flowed  during  application. 

Simultaneously,  a  small  amount  of  air  will 

generally be expelled from the modulator 

exhaust port.

QR

De-energized De-energized

The internal bias piston blocks air from the 

brake chamber from moving back through the 

modulator. Instead, all the air is exhausted 

out the modulator exhaust port.

HF

De-energized De-energized

Air from the brake chambers moves back 

through the modulator in the reverse 

direction  as  it  flowed  during  application.  

Simultaneously, air will be expelled from the 

modulator exhaust port. 

HF and QR De-energized De-energized

Air pressure supplied to the modulator exits 

the modulator delivery port and flows to the 

service brake chambers.

Antilock Exhaust HF and QR Energized

Energized

Air from the brake chambers exhausts 

through the modulator exhaust port. 

HF and QR Energized

De-energized

The modulator prevents supply air from 

passing through the modulator and, at the 

same time, prevents air from the brake 

chambers from exhausting. 

HF and QR De-energized De-energized

The modulator re-applies air to the brakes in 

the same manner it did during a non-antilock 

event.