BQ Injection Pump Assembly Production Type and Meaning

1 Injection PumpB H 4 Q 70 R 8＜1＞ ＜2＞ ＜3＞ ＜4＞ ＜5＞ ＜6＞ ＜7＞

Injection Pump Code Name⑴ Compounding Injection Pump⑵ Number of Cylinders⑶ Q is the code name of BQ injection pump⑷ 10 times plunger diameter ⑸ （70 means that plunger diameter is 70mm） Camshaft direction ⑹ （ from driven end ， R is in a clockwise direction ， L is in a

counterclockwise direction） Cam lift ⑺ （8 means that cam lift is 8mm）

2. Governor T - 300 - 1600 Z ＜1＞ ＜2＞ ＜3＞ ＜4＞ ＜5＞

Code Name of Governor⑴ Idle Speed⑵ Variable Speed Governor⑶ Rated Speed⑷ With Positive Calibration Equipment ⑸ （F with negative calibration equipment）

The Main Parameter of BQ Injection Pump AssemblyPlunger diameter（mm）：φ6 φ6.5 φ7 φ7.5 φ8 φ8.5 Cam lift（mm）：7 8No. of cylinders：2 3 4Cylinder bore（mm）：25Maximum speed allowed by injection pump：2100Outlet valve holding thread：M12×1.25Fuel return pipe connecting thread：M12×1.25 or M14×1.25Lubricating method : splash or force-feed

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Installing method : flangePosition step: φ46 φ50 φ68 φ70 φ78

BQ Injection Pump Assembly Structure and Work Principle

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Fig.2 Four-cylinder BQ injection pump assembly

Four-cylinder BQ Injection Pump Components Order and Name (Fig.2) 1. delivery valve holder2. O seal ring3. volume reducer4. delivery valve spring5. delivery valve washer6. delivery valve assembly7. plunger and barrel assembly8. nut9. (spring) washer10. washer11. pre-stroke adjusting gasket12. flange sleeve13. plunger bushing positioning pin14. O seal ring15. O seal ring16. O seal ring17. control-sleeve gear18. washer19. joint seat for inlet pipe20. copper gasket21. copper gasket22. joint screw for inlet pipe23. washer24. joint seat for leak of pipe25. copper gasket26. copper gasket27. joint screw for leak of pipe28. copper gasket29. fuel channel plug30. nut 31. idle limit screw32. copper gasket33. gear lever cover34. key35. camshaft36. adjusting gasket37. bearing38. O seal ring39. front bearing cover40. reinforced rubber fuel seal41. screw42. upper plunger spring seat43. plunger spring44. lower plunger spring seat45. tappet46. roller pin47. roller48. roller bush49. bottom cover plate seal gasket50. bottom cover plate51. (spring) gasket52. screw53. O seal ring54. washer55. tappet positioning screw56. washer57. gear lever positioning screw58. pump body part59. stud60. gear lever61. release spring62. release spring circlip

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63. circlip64. gear lever bushing 65. washer66. bleed screw67. stud

TQA Governor Components Order and Name

1. flyweight part2. washer3. nut4. governing sleeve5. T-shaped supporting block6. circlip7. counter shaft washer8. governing lever9. governing lever washer10.bearing11.counter shaft bearing limit bushing12.pin 13.rivet14.connecting pin15.cross pin16.connecting panel17.cross pin18.spring tension panel 19.governing spring hook hitch20.governing spring21.screw22.(spring) washer23.connecting jacket24.connecting pin25.governing arm26.bearing27.governor rear case seal gasket28.high speed limit screw29.high speed limit nut30.lead seal

36. copper gasket37. outer bush38. hex nut39. carrier rod40. calibration spring41. pre-tight strength adjusting nut42. nut43. calibration stroke adjusting screw44. nut45. copper gasket46. crown nut47. dipstick part48. O seal ring49. dipstick jacket50. screw51. seal cover52. small rear cover seal gasket53. positioning screw54. washer55. bolt56. (spring) washer57. washer58. governor rear case59. circlip60. O seal ring61. counter shaft62. O seal ring63. circlip64. left engine stop shaft65. O seal ring

71. screw72. left engine stop shaft release

spring73. governing shaft74. circlip75. circlip76. O seal ring77. spring rocker arm78. (spring) washer79. screw80. screw81. (spring) washer82. left engine governing handle

release spring83. left engine governing handle84. pin85. handle pin86. screw87. saddle elastic washer88. nut89. gasket90. starting spring

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31.washer32.breather part33.plug34.nameplate35.rivet

66. stop shaft connecting panel67. handle pin68. pin69. screw70. washer

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The Structure and Work Principle of BQ Injection Pump一、 Structure

BQ pump adopts in-line one-piece closed structure, and it is composed of pump body, delivery fuel system, fuel volume controlling mechanism, driven mechanism, and so on. Its structure is shown in Fig.4.

The material of BQ pump body is aluminum alloy. Because of its one-piece closed structure, it has higher strength and rigidity, and it can bear higher pump end pressure.

The pump delivery fuel system adopts pre-installation hanging structure. The plunger hangs into flange sleeve, and it is positioned by positioning pin pressed into flange sleeve. Delivery valve holder positions plunger and barrel assembly, delivery valve spring, volume reducer and delivery valve washer into flange sleeve. The flange sleeve hangs into installing hole of pump body as one-piece, and positioned with stud, and low pressure sealed with O-ring. There are waist holes. Rotate it can rotate plunger bushing in order to adjust unevenness of each cylinder fuel volume. Using pre-stroke adjusting gasket between flange sleeve and pump body can adjust pre-stroke and fuel delivery interval angle of each cylinder. Its structure is shown in Fig.5.

The fuel volume controlling mechanism for BQ pump adopts rack and gear ring structure, see Fig.6. Its driven mechanism is composed of camshaft part, tappet part and plunger spring.

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二、 Injection Pump Work Principle

As shown in Fig.7, when camshaft rotates under driven of engine, the plunger of each cylinder reciprocates in the function of camshaft and plunger spring. When camshaft turns plunger up, and plunger upper end closes fuel return hole (the high hole of plunger bushing is the fuel return hole), fuel in pump is

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compressed. With increase of fuel pressure, delivery valve lifts, and fuel is supplied through delivery valve. The plunger continues lifting. The edge of fuel controlling skew slot links fuel channel at top of plunger and fuel return hole of plunger bushing; high pressure fuel returns to low pressure fuel channel through vertical slot at top of plunger, fuel controlling beveled slot, fuel return hole of plunger bushing. At this time, fuel delivery is stopped. The plunger continues lifting to top dead center, with the movement of camshaft, and in the function of plunger spring, it starts to move down. When the top end of plunger opens up fuel return hole, one circle is completed. The fuel volume of each circle is controlled by gear lever. Pull the gear lever; adjusting gear moves along plunger bushing, and plunger rotates the same angle as adjusting gear. The position of fuel controlling edge and fuel return hole is changed, which changes effective stroke of plunger, and circle fuel volume. Gear lever connects with governor. In the operation of pump, governor controls the fuel delivery. 三、 Governor Structure

BQ pump governor is a mechanical centrifugal variable speed governor with characteristics of easy structure, good realibility and small governing handle controlling force. Its structure is shown in Fig.8 and Fig.9.

Flyweight is fixed on pump camshaft. When speed increases and flyweight spreads, push governing sleeve move along axial. Governing lever group and governing arm group are installed on governor rear case through counter shaft. Governing lever group upper end connects with gear lever by connecting panel, and the bottom contacts with governing sleeve. Governing arm group upper end connects with governing spring. Starting spring is installed at the bottom of governing arm group and governing lever group. The calibrator assembly and stop shaft are installed on governor rear case, and they control fuel volume and stop engine by governing arm group.

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The structure of positive calibration is shown in Fig.11. Screw in adjusting screw for calibration stroke, stroke “a” and calibration fuel volume will be reduced, otherwise, they will be increased. Screw in pre-tight strength adjusting nut, and pre-tight strength of calibration spring will be increased, then calibrator speed will be reduced, otherwise, it will be increased.

The negative calibrator is shown in Fig.12. Loosen big nut, and screw in calibrator assembly, the negative calibration stroke will be increased, and fuel volume will be reduced, otherwise, negative calibration stroke will be reduced, and fuel volume will be increased. Loosen small nut, and screw in negative calibration pre-tight strength nut, then the spring strength will be increased, negative calibration speed will be increased too, otherwise, speed will be reduced

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Injection Pump Governor Assembly for Generator Set ( following figure)

The positive calibrator for generating pump is rigidity. When adjusting it, loosen 21 crown nut, and screw in positive calibrator, the power will be reduced, otherwise, it will be increased.

When adjusting stabilizer, loosen 21 crown nut, and screw in stabilizer, and increase pre-tight strength, the speed rate will be increased, otherwise, it will be reduced.

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四、 Governor Work PrincipleWhen camshaft is rotating, the centrifugal force of flyweight changes into axial force

through governing sleeve. It acts on governing spring by governing lever, starting spring and governing arm. When the axial force of flyweight is balance with the force of governing spring, the governor will keep in balance.

When speed is increased, the centrifugal force of flyweight will be increased, so does the axial force correspondingly. The balance between axial force and spring force is destroyed. The increasing axial force acts on governing spring by lever system, and forces

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gear lever to move to fuel reducing direction. In the same way, when speed is reduced, gear lever moves to fuel increasing direction, and then carries out adjusting function of governor.

Disassembly and Assembly of BQ Injection Pump AssemblyBefore disassembly of injection pump, clean the outer with gasoline, and keep work place clean.

一、 Disassembly1. It begins with governor. Remove lock bolt of governor rear case, and pull rear case

out slightly, next take splint pin from connecting panel, then take off connecting panel from gear lever, and disassemble governor rear case assembly. Remove flyweight lock nut with socket wrench, and remove flyweight from camshaft with M5 bolt.

2. After disassembling governor, disassemble injection pump.2.1 Screw out two lock nuts of flange sleeve, and hit flange sleeve part with wooden

stick, after loosening, remove flange sleeve part of each cylinder. Next, take off adjusting gear with tweezers, when do it, take care the position of adjusting gear and mark of gear lever. And then clip the top end , rotate 60°,and take out plunger.

2.2 Remove tappet-positioning screw, rotate camshaft, and make tappet assembly of each cylinder at top dead center. The steel wires ￠ 3.5 are inserted into tappet-position screw hole, support the tappet, remove front bearing cover, and take off camshaft assembly.

The fuel pump is made to invert and clip on clamp. Disassemble bottom cover plate, press tappet roller with copper stick, take out ￠ 3.5 steel wire, and remove tappet assembly, lower plunger spring seat, plunger spring and upper plunger spring seat.二、 Check Components

After disassembly, all components should be cleaned in diesel oil, and check the following items:

1. The worn condition of plunger and delivery valve assembly.2. The worn condition of cam appearance and tappet roller.3. The worn condition of bearing, whether plunger spring and delivery valve spring

breaks.三、 Assembly

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Assembly and disassembly of pump are just opposite. Take care the following points:

1. Change all O-rings and seal gaskets. O-rings need not be distorted.2. The moving clearance of camshaft is adjusted in 0.02-0.05mm with adjusting gasket.

3. When installing plunger, the flat position at bottom of plunger is at that of lower plunger spring seat. After the flat position at bottom of plunger going into lower plunger spring seat, clip the top of plunger with tweezers, and move plunger making its top vertical slot to one side of gear lever; when installing adjusting gear, move it slightly with tweezers, making its mark aim at the mark of gear lever according to the position of disassembly. When installing flange sleeve, make the mark of it move to one side of gear lever, and then check its glide.

The Test of BQ Pump Assembly1. The connection of pump and test table should be concentric. Its driven is no-clearance.2. Pour diesel oil HC-11 or HC-14 into pump to rated surface, and discharge the air of fuel

channel.3. Adjust fuel delivery included angle of each cylinder

Take the first cylinder (close to pump delivery end) as standard cylinder. Determine the interval of each cylinder delivery starting point according to delivery order.

4. Determination of zero point of gear leverScrew out calibrator assembly, and increase speed to starting speed; pull governing handle, and install stroke gauge at zero point.

5. Adjustment of declared work condition with stroke gauge⑴

Increase speed to rated speed. Pull governing handle, making it contact with high speed limit screw, and require that stroke gauge is at 4mm at this time, next screw in calibrator assembly, and make the gauge at 4-5mm. Determine whether average fuel at rated point conforms to requirement. If fuel is high, screw in calibrator assembly, otherwise, screw it out; then check unevenness of each cylinder, if it doesn’t conform to requirement, adjust flange sleeve. When adjusting, firstly screw out two fixing nuts of flange sleeve, and pull flange sleeve with screwdriver. From up to down, when it turns in a clockwise direction, fuel volume is reduced, otherwise, it is increased. After adjusting, screw in fixing nuts evenly. The torque is 9.3-12.3N.m. Increase speed to 1.010-1.025 times of rated speed, and adjust high speed limit screw, making stroke indicated in stroke gauge is 0.03-0.06mm bigger than it at rated speed; reduce speed to rated speed, and check the reading of gauge, if not back to rated stroke, check mobility of governing mechanism. After adjusting all, screw up the nut fixing high speed screw and hex nut fixing calibrator outer screw.

without stroke gauge⑵ First make the waist hole in center. Next increase speed to rated speed. Adjust

governing handle, and determine fuel volume at rated point, if average fuel volume doesn’t conform to requirement, adjust calibrator assembly. If average fuel is high, screw it in, otherwise, screw it out; at the same time, check fuel unevenness, if it doesn’t conform to requirement, adjust flange sleeve, its adjusting method is as same as that with

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stroke gauge.Check of governing point: reduce 20r/min from rated speed, the average fuel is no

more than rated fuel at this time. If fuel is high, screw high speed limit screw up, making fuel volume equal to rated volume, next increase speed to that is 50r/min higher than rated speed, the average fuel volume should be reduced, if not, screw high speed limit screw down. Then adjust speed to rated speed, and observe whether rated volume changes, if changes, adjust calibrator assembly, till it conforms to requirement.

After adjusting all, screw up the nut fixing high speed screw and hex nut fixing calibrator outer screw.

6. Check of fuel interrupted speed After adjusting rated volume, governing handle is still at maximum position. Increase speed to fuel interrupted speed regulated by each type. Fuel delivery of pump is no more than a quarter of that at idle speed. If not conform to requirement, change the governing spring, and recalibrate work condition and start to adjust.7. Check and adjustment of positive calibration condition Reduce pump speed to calibration speed. First check calibration fuel volume (before check it, screw up the nut fixing pre-tight strength adjusting nut, in order to avoid loosening and affect calibration spring pre-tight strength). If the average volume is bigger, screw in calibration stroke adjusting screw, otherwise, screw it out; second, check unevenness of fuel volume in each cylinder, if unevenness is too bad, adjust flange sleeve properly, at the same time, increase speed to rated speed. Then observe whether unevenness of fuel volume in each cylinder is in requirement range. If not, change delivery valve assembly, adjust and calibrate fuel volume again, till it reaches to requirement. After adjustment, screw up calibration stroke adjusting screw to avoid loosening.8. Adjust negative calibration stroke Must operate with stroke gauge in the test of negative calibration. Firstly, reduce the speed of table test to end point of negative calibration, and record this stroke N. Screw in negative calibration assembly (pre-tight strength for negative calibration spring need to be big enough at this time) 0.45-0.6 (if has fuel volume requirement, according to fuel volume), and screw up big nut. Improve speed to negative calibration speed of requirement. Loosen up the nut, and screw out pre-tight strength nut, when stroke is to be N+0.1 (or fuel volume is smaller than it is at stroke N). Screw up the nut, and recheck fuel volume at end point of negative calibration or stroke. If not proper, readjust it according to above steps. 9.Starting condition Place governing handle at maximum position. Speed is reduced to 150r/min. Check starting fuel volume; if the volume is small, consider it by the following two items:

1. If has stroke gauge, increase speed to rated speed, and adjust rated stroke to max. Next adjust flange sleeve, making rated fuel volume conform to requirement. Then reduce speed to starting speed, and observe whether starting fuel volume conforms to requirement. If it is still small, change plunger assembly, and readjust rated fuel, calibration fuel, and unevenness of calibration fuel.

2. If has not stroke gauge, it may be unevenness of distribution. Screw in calibrator assembly, and readjust flange sleeve, making rated fuel, calibration fuel and starting fuel volume conform to requirement.

10. Check and adjustment of idle conditionPlace governing handle at idle position. Speed is rated idle speed. Check idle fuel, if

average volume doesn’t conform to requirement; adjust idle limit screw till it conforms to requirement. Next check unevenness of fuel, if it doesn’t conform to requirement, adjust flange sleeve to make it conform to requirement. At the same time, increase speed to rated

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speed. Observe whether unevenness of fuel in rated condition is over proof. If be, change delivery valve assembly, and readjust rated fuel, calibration fuel and unevenness of idle fuel. After adjusting, speed is increased to 500r/min; pump should interrupt fuel, and move up and down with speed. The gear lever should respond sensitively.

After adjusting all, screw up the nut fixing idle limit screw in order to avoid loosening.11. Check fuel interrupted of stop handle Pump is operated in idle work condition. Wrenching stop handle, pump should stop delivering fuel. Loosen up stop handle, gear lever returns to idle position quickly.12. Check and adjustment of acceleration After adjustment of pump that has acceleration requirement in idle condition. Adjust its acceleration, namely, governing handle is at full load position. When speed is 550r/min, screw in accelerator assembly, making fuel conform to requirement, and readjust idle interrupted speed.13. Others should be adjusted according relational prescriptions.

The Test of Injection Pump for Generator Set on the Engine1. Improve speed to rated speed. The accelerator is at full load position, and positive

calibrator quits to outer.2. Turn into stabilizer, the torque is 3-5N.m bigger than actual requirement (or speed is 20-

40r/min higher), next check speed rate. If too high, change into small rigidity governor spring; if too low, change into big rigidity one

3. Back to speed at rated point. At this, the torque is 3-5N.m (or speed is 20-40r/min higher). Screw in positive calibrator till it conforms to requirement, and lock it.

The Common Troubles and Adjustment of Injection Pump for Generator Set on the Engine

1. Insufficient powerAdjust positive calibrator slightly, and turn out it (total fuel increasing), if invalid, push the idle stabilizer to be properly.

2. Excessive power Adjusting positive calibrator slightly, turn in it (total fuel reducing)3. High speed rate Push the stabilizer to outer, and then back to rate point to see whether power is reduced. If

reduced, change into stabilizer spring of small rigidity.4. Running away

Change a stabilizer spring of bigger rigidity, but speed rate need conform to requirement. Notice that the stabilizer is not more rigid better; do not change into the most rigid spring (may interfere idle speed and so on).

5. Higher idle speedKeep accelerator at idle speed. Turn high speed limit screw up slightly, and turn stabilizer out slightly, then adjust it according to method, till idle speed conforms to requirement.

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Usage, Maintenance and Troubles Remedies一、Operation1. Check whether lubricating fuel in pump is in graduation range before installing.2. Discharge the air in fuel channel, and adjust fuel delivery angle before starting.3. In the operation, take care whether the pump is overheating or lubricating fuel is diluted or

components loosen up. If it is, repair it in time.二、Maintenance1. The plunger and delivery valve assembly are accurate. Its life relates to cleanness of

diesel oil. Therefore diesel oil must be clean, and no water. The filter element must be changed in time.

2. The lubricating oil in pump must be checked and changed in time.三、Troubles and Remedies1. Starting troubles:

incorrect fuel delivery angle readjust⑴ ⑴ has air in fuel system discharge the air⑵ ⑵ no fuel delivery repair delivery pump⑶ ⑶ the plunger assembly worn out heavily⑷ 　　　　⑷ change plunger assembly poor atomization of the nozzle⑸ 　　　　　　　⑸ change nozzle assembly

2. Insufficient power: incorrect fuel delivery angle readjust⑴ ⑴ insufficient fuel volume readjust⑵ ⑵ the plunger assembly worn out heavily change plunger assembly⑶ ⑶ poor atomization of the nozzle change nozzle assembly⑷ ⑷

3. Running away governor failure repair⑴ ⑴ rack is locked repair⑵ ⑵

4. Stop suddenly fuel delivery is interrupted repair low pressure fuel channel⑴ ⑴ rack is locked at the fuel interrupted position repair⑵ ⑵ governor failure repair⑶ ⑶

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