A high-pressure fuel pump (high pressure fuel pump) of the Compact-40 type with an electronic control system (ECS) assembled with an actuator mechanism, a fuel priming pump and a damper clutch is shown in Figure 1
Designation of injection pump with ESU used on YaMZ-6583.10 engines: full 179.1111002-30, conditional 179.2-30.
Designation of injection pump without ESU: 179.1111005.
The main parameters and characteristics of the injection pump with ESU are given in the table.
Design and operation of high pressure fuel pump
With the high-pressure fuel pump 1, an actuator mechanism (MI) 2, a fuel priming pump (FPU) 3 and a damper coupling 4 are combined in one unit (Fig. 1).
Injection pump, consisting of sections (individual pumping elements) located in a common housing, is installed in the engine camber between the rows of cylinders.
The number of injection pump sections corresponds to the number of engine cylinders.
The device of the injection pump section is shown in Figure 2.
In housing 1 of the injection pump, there are housings of sections 22 with plunger pairs, pressure valves, plunger pushers 3 and fuel fittings 23, to which high-pressure fuel lines are connected.
Plunger 12 and plunger sleeve 13, discharge valve seat 16 and discharge valve 17 are precision pairs, which can only be replaced as a complete set.
The plunger sleeve is fixed in a certain position by pin 14 pressed into the section body.
The plunger is driven by camshaft 2 via a roller follower.
The pusher spring 5 constantly presses the pusher roller against the cam through the lower pusher spring plate 4.
Plunger pushers, having flats on the side surfaces, are kept from turning by clamps pressed into the injection pump housing.
The design of the plunger pair allows you to dose fuel by changing the moment of the start and end of the supply.
To change the amount and moment of the start of the fuel supply, the plunger in the sleeve is rotated by the rotary sleeve 8, which engages with the fuel pump rail 9.
Adjustment of the uniformity of the fuel supply at the maximum mode by each section of the high-pressure fuel pump is carried out by turning the section body with the nuts 27 of the sections fastening loosened.
Changing the start of fuel supply depending on its value (engine load) is provided by control edges made on the end of the plunger.
The section works as follows.
When the plunger moves down under the action of a spring, fuel under slight pressure created by the fuel priming pump enters the over-plunger space through the longitudinal channel of the injection pump housing.
When the plunger moves upwards, fuel enters the high-pressure fuel line through the delivery valve and is bypassed into the fuel supply channel until the end edge of the plunger closes the inlet of the plunger sleeve.
With further upward movement of the plunger, the fuel pressure in the space above the plunger increases sharply.
When the pressure reaches a value that exceeds the force of the nozzle spring, the nozzle needle will rise and the process of injecting fuel into the engine cylinder will begin.
As the plunger moves further upwards, the helical edges of the plunger open shut-off holes in the sleeve, which causes a sharp drop in fuel pressure in the fuel line.
At the same time, the discharge valve, lowering into the seat under the action of a spring, increases the volume in the fuel line between the nozzle and the valve. This achieves a more precise end of fuel injection and unloading of the high pressure fuel line.
On the inner surface of the plunger sleeve there is an annular groove, and in the wall there is a hole for draining fuel that has leaked through the gap in the plunger pair.
The gaps between the plunger bushing and the section body, the section body and the injection pump body are sealed with rubber sealing rings 10, 11, 20.
From the cavity around the plunger sleeve, the leaked fuel enters through the groove on the plunger sleeve into the fuel channel of the injection pump housing and then through the bypass valve through the fuel line to the fuel tank.
In the lower part of the injection pump housing there is a camshaft rotating in tapered roller bearings. It has, depending on the model of the injection pump, one or two intermediate supports.
The camshaft is installed with an axial interference (0.01 ... 0.07) mm, which is provided by shims installed between the bearing cover and the injection pump housing.
The sections are connected to the actuator through the fuel pump rail, which moves in guide bushings pressed into the injection pump housing.
Speaker and From the body, the end of the rail is protected by the rail cover 5 (Fig. 1).
Main parameters and characteristics of injection pump with ESU
Parameter name - Value
Number of sections 8
Plunger diameter 12 mm
Plunger stroke 14 mm
Direction of rotation of the camshaft (drive side) - Clockwise (right)
Section order (drive side) 1-3-6-2-4-5-7-8
Rated camshaft speed 950 min -1
Camshaft speed corresponding to maximum torque mode 600 min -1
Cam shaft speed at minimum idle 300 min ‑1
Lubrication method - centralized from the engine lubrication system
Permissible roll angles, no more than:
- - longitudinal 35º
- - transverse 25º
The actuating mechanism is an electromagnet placed in a housing attached to the injection pump housing.
An electromagnet, receiving a command from an electronic control unit, moves the fuel pump rail to a predetermined position through a system of levers.
When the ESA is turned off, a spring connected to the rail moves it to the off feed position.
Fuel priming pump 3 (Fig. 3) is a piston type, double-acting, designed to supply fuel from the fuel tank through the coarse and fine fuel filters to the injection pump.
The performance of the TVC significantly exceeds the performance of the high-pressure fuel pump, which guarantees the stability of the fuel supply process from cycle to cycle.
The TVC device is shown in Figure 3.
The FLC is mounted on the injection pump housing and is actuated by a double cam of the camshaft.
In the body of the fuel priming pump 1, there are: TPN piston 2, piston spring 3, fixed with spring plug 5, pusher rod bushing 6 with pusher rod 7, piston pusher 8.
Four valve seats 14 are pressed into the TPN housing, to which the fuel pump valves are pressed by valve springs 16, of which valve 29 is suction, and valve 15 is discharge.
The body cavity of the TVC, in which the piston moves, is connected by channels to the valve cavities.
The piston is driven by a pusher through the rod. The pusher roller 13 rotates on the floating axis of the roller 11.
The roller and the axle are fixed by the retaining ring of the pusher 10.
The pusher biscuit 9 prevents the pusher from turning. The bushing of the pusher rod, which serves as a guide for the rod, is screwed into the TV body with a special adhesive.
The sleeve and the stem make up a precision pair, which can only be replaced as a complete set.
A manual fuel priming pump is installed above the suction cavity of the TPN, the device of which is also shown in Figure 3.
This pump is used to remove air from the fuel system before starting the engine and to fill the low pressure line with fuel after maintenance of the fuel system.
To put it into action, it is necessary to unscrew the rod 22 with the piston 20 from the cylinder body 19 by the handle 23 and pump the engine fuel system.
DAMPER CLUTCH
The injection pump is equipped with a damper clutch designed to protect mechanisms from destruction. It is mounted on the tapered surface of the front end of the camshaft with an interference fit created by the ring nut.
The damper coupling is secured with a key against rotation.
The damper coupling is a non-separable design with a flywheel freely rotating in a special high-viscosity fluid.
Dents on the damper clutch housing can damage it.
Nozzle 51-21 (Fig. 4), which is part of the fuel equipment, refers to closed-type nozzles with a multi-jet atomizer and hydraulic control of the needle lift.
The parts of the nozzle are assembled in the nozzle body 7. Spacer 3 and the nozzle body 1 are attached to the lower end of the nozzle with the nozzle nut 5, inside of which there is a nozzle stop needle 2.
The mutual arrangement of the nozzle body, spacer and sprayer body is determined by pins 4 pressed into the spacer.
The atomizer body and the atomizer needle are a precision pair.
The injection start pressure is adjusted using a set of shims 9.
Fuel is supplied directly to the fitting of the nozzle body through slotted filter 10.
Fuel leaking through the gap between the needle and the atomizer body is discharged through a threaded hole in the top of the nozzle body.
The nozzle is installed in the glass of the cylinder head. Under the butt end of the sprayer nut, install There is a corrugated washer for sealing against gas breakthrough.
The nozzle is completed with an assembled atomizer model DLLA 160 P from BOSCH.