"Gazelle" Gas-2705>> Brake system>> Pressure regulator

Fig. 8.4. A pressure regulator: With = 28—32 mm (for buses), 13—17 mm (for motor vans); 1 — press the lever; 2 — a pin; 3 — a fixing bolt; 4 — an axis of the press lever; 5 — a nut; 6 — an axis; 7 — the case; 8 and 9 — regulator arms; 10 — a counternut; 11 — an adjusting bolt; 12 — a loading spring; 13 — a spring; 14 — a piston sleeve; 15 — an operating cone; 16 — a clamping spring; 17 — a ball; 18 — persistent скоба; 19 — a returnable spring; 20 — the plug; 21 — the piston; 22 — a protective cover; 23 — a bridge arm; 24 — a rack; 25 — a spring washer

The pressure regulator (fig. 8.4) corrects pressure of the brake liquid arriving to brake mechanisms of back wheels, depending on car loading that prevents car drift at intensive braking.
The regulator fastens to the left longeron of a frame through an arm 8, and by means of a loading spring 12 and racks 24 is connected with the back bridge of the car. The loading spring through press the lever 1 operates with the top short end on the external end of the piston 21, and by the long end through a rack 24 is connected to an arm 23 welded on the back bridge of the car.
The pressure regulator consists of the case 7 in which the sleeve 14 is established and the plug 20 is screwed.
The step piston 21 will mix up in the plug and a sleeve, thus in the cavities I constantly connected with the main cylinder, there is a part of the piston of small diameter, and in the cavities II constantly connected with wheel cylinders of back brake mechanisms, — большего diameter. On the piston the operating cone 15 which influences a ball 17 which are in an aperture of a sleeve 14 is fixed. The ball is kept in an aperture by a lamellar spring 16.
The loading spring 12, which effort in direct ratio to car loading, defines the beginning of inclusion of a regulator, and a difference of diameters of pistons — updating of pressure of the liquid arriving to back brake mechanisms.
To the introduction into action of a regulator pressure of a liquid in cavities I and II is identical, as under the influence of a spring 19 and a loading spring 12 piston 21 through persistent скобу 18 is pressed to a sleeve 14, and the ball 17 is lifted from a saddle by operating cone 15, as provides free passage of a liquid from a cavity I in a cavity II.
At braking in the beginning pressure of a liquid in cavities I and II will be identical until the force received from pressure upon the most part of the piston 21 (a cavity II), will not be more sums of the forces received from action of springs 12 and 19 and from pressure of a liquid on the area, formed between big and small in diameters of the piston (a cavity I). In this case the piston will move to the left (on drawing), the operating cone 15 will depart from a ball 17 which will move to a saddle of a sleeve 14, than will separate a cavity I with a cavity II. From this point on pressure of a liquid in the cavities II arriving to back brake mechanisms, will grow more slowly and thus will be less, than in a cavity I.
At removal of effort from a brake pedal pressure in a cavity I falls, the piston 21 will come back in a starting position (in drawing to the right), and an operating cone, having lifted a ball, will open access of a liquid from a cavity II in a cavity I.
The sleeve 14 pistons under the influence of pressure in a cavity II will move to the left (on drawing), and the ball 17 will depart from a saddle under the influence of an operating cone 15, having opened access of a liquid from a cavity II in a cavity I.
After pressure drop of a liquid a sleeve of the piston 14 and the piston 21 under the influence of a returnable spring washer 25 and springs 19 will return to a starting position.