ED.pc2.5 & PC2.6 2_Injection.E 00

 

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The individual injection pumps of engine are directly driven by independ independent ent roller tappets. They are fixed on the crankcase upper face by means of the pump control device

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The individual injection pumps of the engine are directly driven by independent roller tappets (see maintenance manual - chapter 5). They are fastened on the crankcase upper face by means of the pump control device.

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Each pump includes the following elements essentially: - the body body (1)  (1) equipped with both fuel supply and discharge flanges  flanges  (201 and 202), and with the safety valve (37), - the barrel-plunger assembly (12) oriented in the pump body by the dog point screw (31), - the rotating driving system of the plunger consisting of the plunger guiding gear   (27) and the fuel rack (26),

- the pump head including the delivery valve (8), the spring spring (9)  (9) of the thrust piece (10), the seat seat   (5) and the connection connection (3)  (3) tightened on the pump body by means of the screws crews  (7), - the tappet assembly connecting the plunger of the pump with the roller tappet maintenance manual chapter 9 for details.

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see

Injection timing: 13° before TDC PC2-5 Injection pressure (at nominal power): 940 bar for distillate fuel application / 970 bar for residual fuel application

Safety valve calibration pressure: 0.35 bar

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The fuel circulates through bores (A) and (B)  (B)  in the filling chamber (C) provided between body and barrel. While flowing through the two bores of the barrel, it fills the delivery chamber (D)  (D)  placed between the plunger head and the t he delivery valve. When the plunger, actuated by the cam, closes the ports of the barrel, the pressure rises in the delivery chamber. First, the valve (8) and then, the injector open. The injection goes on until the plunger ramps uncover the barrel ports. The filling chamber (C) is then connected with the delivery chamber (D) through the grooves, the plunger ramps and the barrel ports. Suddenly the pressure drops, the injector and the valve close up. While the plunger ends up its ascending stroke, the fuel which is no longer delivered, flows back to the filling chamber. The delivery stroke (stroke of the plunger during which the ports of the barrel are covered) varies with the angular position of the plunger with regard to the barrel. The translation of the fuel rack (26) and, consequently, the rotation of the plunger guiding gear (27) adjusts the flow rate of the delivered fuel.

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The individual injection pumps of the engine are directly driven by independent roller tappets (see maintenance manual - chapter 5). They are tightened on the crankcase upper face by means of the pump control device.

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Each pump includes the main following elements: - the body body   (1) equipped with both fuel supply and discharge flanges  flanges   (23), and with the safety valve  (39), valve - the barrel-plunger assembly (5) oriented in the pump body by the dog point screw (31)  – see next slide, - the rotating driving system of the plunger consisting of the plunger guiding gear (6) and the rack (7), - the pump head  – see next slide for more details  – including the connection connection (2)  (2) tightened on the pump body by means of the screws screws (22),  (22), - the tappet assembly connecting the plunger of the pump with the roller tappet, made up of: the tappet (10), the restoring spring (8) and the valve-holder   (11), the valves valves   (12) used for the plunger lifting in case of overspeed (see next slide and chapter 9). Injection timing: 13° before TDC (standard value) PC2-6/2 Injection pressure (at nominal nomi nal power): 1160 1160 bar for residual fuel application appl ication

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Elements of the pump head : the delivery valve (18), the spring spring (19)  (19) of the thrust piece (20), the seat seat (17)  (17)

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The fuel circulates through bores bores   (A) and (B)  (B)  in the filling chamber (C) provided between body and barrel.

While flowing through the two bores of the barrel, it fills the delivery chamber (D) placed between the plunger head and the delivery valve. When the plunger, actuated by the cam, closes the ports of the barrel, the pressure rises in the delivery chamber. First, the delivery valve and then, the injector nozzle open. The injection goes on until the plunger ramps uncover the barrel ports. The filling chamber (C) is then connected with the delivery chamber (D) through the grooves, the plunger ramps and the barrel ports. Suddenly the pressure drops, the injector and the valve close up.

While the plunger ends up its ascending stroke, the fuel which is no longer delivered, flows back to the filling chamber. It meets two anti-splash screws at the outlet of the barrel ports. These screws avoid the erosion per cavitation of the body by the fuel under pressure The delivery stroke (stroke of the plunger during which the ports of the barrel are covered) varies with the angular position of the plunger with regard to the barrel. The translation of the fuel rack and, consequently, the rotation of the plunger guiding gear adjusts the flow rate of the delivered fuel.

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PC2-5 The pump-injector connection is ensured by a high pressure pipe (1) crossing the cylinder head and screwed in the injector. The tightness is ensured by a crimped metal joint. joint.  At the other end, it is directly connected to the fuel fue l pump head. Fuel leaks are collected by a tight device including a flange flange (2),  (2), a sleeve sleeve (7)  (7) and a nut nut (9).  (9).

PC2.6/2

The pump-injector connection is ensured by a straight drilled pipe pipe   (1) crossing the cylinder head and screwed in the injector.  Accidental fuel leakages coming from the pump/injector connection are collected by the casings of the injection pump head.

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Fitted in the center of each cylinder head, the injector   sprays directly the fuel in the combustion chamber. A metal gasket (1 (11) 1) ensures the tightness on o n combustion chamber side. The nozzle nozzle (2),  (2), composed of a needle needle   and its box box,, which are paired, is tightened on the injectorholder  (1)  (1) by the nut nut (13);  (13); a pin pin  (6) ensures the positioning. The nozzle opening pressure is determined by the spring spring   (15) pressing on the needle with the tappet (9).

The tension of the spring is obtained by the adjusting screw (12), the latter is blocked by the nut nut   (3). The injector is tightened on the cylinder head by two tie rods (125) with nuts nuts (135).  (135).

Two tubes which are screwed in the waterways block allow cooling water to be circulated across the injector. Injector characteristics

Nozzle: • •

10 x 0.6 x 140° for distillate application 10 x 0.65 x 140° for residual fuel application

Calibration pressure: 240 +/- 5 bar

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leakages, at the level of the nozzle, ( leakages in needle and leakages in the plane of the The fuel leakages,  joint “nozzle - injector-holder” ) flow up through the axial bore of the injector-holder and along the adjusting screw screw.. Then they are collected in the annular chamber formed by the cylinder head and the injectorholder equipped with two O-rings O-rings   (18), then drained to the outside of the cylinder head through the injection pipe duct.

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The   nozzle (2), composed of a needle and its box, which are paired, paired, is tightened on the The injector-holder  (1)  (1) by the nut nut (4)  (4) ;  ; two pins (13) ensures the positioning. The nozzle opening pressure is provided by the spring (8) pressing on the needle with the tappet tappet   (7). The tension of the spring is obtained by the adjusting screw (9), the latter is blocked by the nut nut   (14). The injector is tightened tighten ed on the cylinder head by two tie rods (42) with nuts nuts (40)  (40) and spacer  (41).  (41).

Two tubes which are screwed in the waterways block (115) allow cooling water to be circulated across the injector. injecto r. Nozzle => 10x0.68x140° for all application Calibration pressure: 300 +/- 5 bar

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The fuel leakages, at the level of the nozzle, (leakages in needle and in the plane of the “nozzle  injector-holder”  joint) flow up through the axial bore of the injector-holder and along the adjusting screw. Then, they are collected into the housing of the guide and of the spring and afterwards are driven outside, through the cylinder head.

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