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Bài giảng Hệ thống phanh

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  1. TRƯỜNG ĐẠI HỌC SƯ PHẠM KỸ THUẬT TP.HCM Diagnosis Technician >> Brake >> Brake System KHOA CƠ KHÍ ĐỘNG LỰC HỆ THỐNG PHANH BRAKE SYSTEM
  2. Diagnosis Technician >> Brake >> Brake SystemCÔNG DỤNG Tạo ra lực cản ở bánh xe để: - Giảm tốc độ xe - Dừng xe - Hoặc đậu xe
  3. Diagnosis Technician >> Brake >> Brake SystemPHÂN LOẠI @ Theo chức năng: - Phanh chính - Phanh đậu xe @ Theo dẫn động phanh: - Phanh cơ khí - Phanh thủy lực - Phanh khí nén - Phanh thủy khí
  4. Diagnosis Technician >> Brake >> Brake SystemPHÂN LOẠI @ Theo cơ cấu phanh: - Phanh trống (guốc) - Phanh đĩa - Phanh đai @ Theo trợ lực phanh: - Trợ lực bằng chân không - Trợ lực bằng thủy lực - Trợ lực bằng khí nén Ngoài ra, còn có: - Phanh bằng động cơ - Phanh khí xả
  5. Diagnosis Technician >> Brake >> Brake SystemYÊU CẦU - Lực phanh lớn và tác dụng nhanh (nhạy), có khả năng dừng xe gấp với thời gian và quãng đường phanh ngắn nhất - Hoạt động êm dịu, tính ổn định chuyển động của xe khi phanh cao - Lực phanh phân phối ở các bánh xe theo qui luật phân bố tải trọng - Lực tác dụng lên bàn đạp phanh nhẹ nhưng có khả năng tạo ra lực phanh lớn ở các cơ cấu phanh - Lực phanh ở các cơ cấu phanh phải tỉ lệ với lực tác dụng lên bàn đạp phanh - Thoát nhiệt tốt, có khả năng hoạt động liên tục trong khoảng thời gian dài - Dễ kiểm tra, sửa chữa
  6. Diagnosis Technician >>H BrakeỆ TH >> BrakeỐ SystemNG PHANH THỦY LỰC @ Các bộ phận chính: - Bàn đạp phanh - Bộ trợ lực phanh - Xy lanh chính - Đường ống dẫn động dầu - Các van phân phối và điều chỉnh lực phanh - Cơ cấu phanh (trống, đĩa)
  7. Diagnosis Technician >>H BrakeỆ TH >> BrakeỐ SystemNG PHANH THỦY LỰC @ Bố trí mạch dầu phanh: - Mạch thường (kiểu xe FR) - Mạch chéo (kiểu xe FF) -
  8. Diagnosis Technician >> Brake >> BrakeXY System LANH CHÍNH @ Theo chức năng: - Phanh chính - Phanh đậu xe @ Theo dẫn động phanh: - Phanh cơ khí - Phanh thủy lực - Phanh khí nén - Phanh thủy khí
  9. Diagnosis Technician >> Brake >> Brake System Brake System Brake 6. Parking brake 1. Brake pedal 5. Disc brake 2. Brake booster 3. Master cylinder 4. Proportioning valve (1) Disc brake (2) Disc brake (1/1)
  10. Diagnosis Technician >> Brake >> Brake System Master Cylinder General & Construction 1.General/2.Construction Minimum (5) (7) Fluid level sensor Rubber piston cups (6) Reservoir tank (4) No.2 return spring (3) No.2 piston (2) No.1 return spring (1) No.1 piston (1/3)
  11. Diagnosis Technician >> Brake >> Brake System Master Cylinder General & Construction 3. Principles Principle of the lever Pascal’s law Fulcrum 2 Wheel cylinder F2 5 cm B Master cylinder 1000 N 2 10 cm2 10 cm b A 2000 N 8 cm 20 cm2 40 cm Push rod 2000 N 400 N F1 Same pressure 4000 N (2000 kPa) a The principle of the lever is applied by the brake pedal as follows. Operating force: Amount of movement: A F1 A = F2 B  F2 = F1 B b B A B = a = b b = a F1: Pedal force a A B A F2: Push rod output force a: Amount of movement of pedal edge A1: Distance from center of brake pedal to b: Amount of movement of push rod fulcrum B: Distance from push rod to fulcrum (2/3)
  12. Diagnosis Technician >> Brake >> Brake System Master Cylinder General & Construction 4.Types of brake lines FR vehicle Front FF vehicle Front (3/3)
  13. Diagnosis Technician >> Brake >> Brake System Master Cylinder Operation 1.Normal operation No.1 return No.2 return spring spring Compensating port Inlet port No.2 piston No.1 piston to front side to Rear side FF vehicle No.1 piston cup Stopper bolt No.2 piston cup (1/4)
  14. Diagnosis Technician >> Brake >> Brake System Master Cylinder Operation Compensating port Piston cup to Front side to Rear side No.2 piston No.1 piston Brake pedal depressed (1) Brake pedal depressed (2) (2/4)
  15. Diagnosis Technician >> Brake >> Brake System Master Cylinder Operation Orifices Inlet port Compensating port Piston cup to Front side to Rear side Brake pedal released (1) Brake pedal released (2) (3/4)
  16. Diagnosis Technician >> Brake >> Brake System Master Cylinder Operation to Front side to Rear side No.2 piston No.1 piston Contact (4/4)
  17. Diagnosis Technician >> Brake >> Brake System Master Cylinder Operation to Front side to Rear side No.2 piston No.1 piston Piston contacts wall (4/4)
  18. Diagnosis Technician >> Brake >> Brake System Brake Booster General & Construction 1.General/ 2.Construction (12) Constant pressure chamber (5) Diaphragm (3) Booster piston Vacuum (13) Check valve (8) Reaction disc (7) Valve body Air (1) Valve operating Brake master cylinder rod (9) Air cleaner (10) Body seal (2) Push rod (10) Body seal (11) Variable pressure chamber (4) Booster body (6) Diaphragm spring HINT: Tandem brake booster (1/1)
  19. Diagnosis Technician >> Brake >> Brake System Brake Booster Operation 1.Brakes not applied Booster piston Control valve Diaphragm Valve operating rod spring Constant pressure Variable pressure chamber chamber Piston Vacuum valve (opened) Control valve Control valve spring Passage A Valve body Constant pressure chamber Air valve (closed) Valve operating Air valve return Air cleaner spring element Variable pressure Passage B chamber (1/1)
  20. Diagnosis Technician >> Brake >> Brake System Brake Booster Operation 2.Brakes applied Booster piston Control valve Valve operating rod Diaphragm spring Constant pressure Variable pressure chamber chamber Passage A Vacuum valve (closed) Constant Piston pressure Control valve chamber Control valve Control valve Control valve spring spring Booster push Air rod Air valve Valve operating (opened) rod Passage B Air cleaner element Air valve Passage B Variable pressure (closed) chamber (1/1)
  21. Diagnosis Technician >> Brake >> Brake System Brake Booster Operation 3.Holding state Booster piston Control valve Valve operating rod Diaphragm spring Constant pressure Variable pressure chamber chamber Piston Vacuum valve Control valve Constant pressure Control valve spring chamber Stopped Valve operating rod Air valve Variable pressure (closed) chamber (1/1)
  22. Diagnosis Technician >> Brake >> Brake System Brake Booster Operation 4.Maximum boost Booster piston Control valve Valve operating rod Diaphragm spring Constant pressure Variable pressure chamber chamber Constant Piston Vacuum valve pressure chamber Control valve Booster Control valve spring push rod Air Air valve (opened) Valve operating rod Variable pressure chamber (1/1)
  23. Diagnosis Technician >> Brake >> Brake System Brake Booster Operation 5.Non-vacuum Booster piston condition Control valve Valve operating rod Diaphragm spring Constant pressure Variable pressure chamber chamber Constant Piston Vacuum valve pressure chamber Control valve Booster Valve body push rod Air valve Valve operating rod Valve stopper key Reaction disc Variable pressure chamber (1/1)
  24. Diagnosis Technician >> Brake >> Brake System Brake Booster Reaction mechanism 1.General/2.Operation Valve body Booster Air valve push rod Reaction disc 80 N (to Valve body) 100 N 20 N (to Air valve) 1cm2 (20N) 4cm2 (80N) (1/1)
  25. Diagnosis Technician >> Brake >> Brake System Brake Booster Gap Adjustment of Push Rod Choke applied SST Thickness gauge SST Accessory tool STT 09737-00010 BRAKE BOOSTER ADJUSTMENT •Thickness Gauge(0.2mm or 0.008inch) and Special Service Tool(SST 09737- 00010)are required to check and adjust the push rod length. • See Repair Manual for details. (1/1)
  26. Diagnosis Technician >> Brake >> Brake System Brake Booster Function Check Airtightness to Intake manifold function cheek Atmospheric pressure Atmospheric pressure Operating cheek to Intake manifold Atmospheric pressure Vacuum Vacuum tightness function cheek to Intake manifold Atmospheric pressure Vacuum (1/1)
  27. Diagnosis Technician >> Brake >> Brake System Brake Booster Function Check 1.Airtightness function check Airtightness to Intake manifold function cheek Atmospheric pressure Atmospheric pressure Operating cheek to Intake manifold Atmospheric pressure Vacuum Vacuum tightness function cheek to Intake manifold Atmospheric pressure Vacuum (1/1)
  28. Diagnosis Technician >> Brake >> Brake System Brake Booster Function Check 2.Operation check Airtightness to Intake manifold function cheek Atmospheric pressure Atmospheric pressure Operating cheek to Intake manifold Atmospheric pressure Vacuum Vacuum tightness function cheek to Intake manifold Atmospheric pressure Vacuum (1/1)
  29. Diagnosis Technician >> Brake >> Brake System Brake Booster Function Check 3.Load airtightness function check Airtightness to Intake manifold function cheek Atmospheric pressure Atmospheric pressure Operating cheek to Intake manifold Atmospheric pressure Vacuum Vacuum tightness function cheek to Intake manifold Atmospheric pressure Vacuum (1/1)
  30. Diagnosis Technician >> Brake >> Brake System Proportioning Valve General & Construction 1.General/2.Construction (a) Desired curve-line of braking force (b) Rear wheel braking fore Contact with P valve Front wheel braking force (4) Compression spring (5) Cylinder cup Front (3) Valve seal (2) Piston (1) Valve body (1/1)
  31. Diagnosis Technician >> Brake >> Brake System Proportioning Valve Operation Cylinder cup from Master cylinder Piston Split point Rear wheel cylinder cylinder wheel Rear pressure Master cylinder pressure Spring to Rear wheel cylinders Master cylinder hydraulic pressure Master cylinder hydraulic pressure Force by the difference in the pressure reception surface area (1/1)
  32. Diagnosis Technician >> Brake >> Brake System Proportioning Valve Operation 1. Operation up to the split point Cylinder cup from Master cylinder Piston Split point Rear wheel cylinder cylinder wheel Rear pressure Master cylinder pressure Spring to Rear wheel cylinders Master cylinder hydraulic pressure Master cylinder hydraulic pressure Force by the difference in the pressure reception surface area Force by the difference in the pressure Spring force reception surface area (1/1)
  33. Diagnosis Technician >> Brake >> Brake System Proportioning Valve Operation 2.Operation of the split point Cylinder cup from Master cylinder in Contact Piston Split point Rear wheel cylinder cylinder wheel Rear pressure Master cylinder pressure Spring to Rear wheel cylinders Master cylinder hydraulic pressure Master cylinder hydraulic pressure Force by the difference in the pressure reception surface area Force by the difference in the pressure Spring force reception surface area (1/1)
  34. Diagnosis Technician >> Brake >> Brake System Proportioning Valve Operation 3.Operation after the split point Cylinder cup from Master cylinder Piston Split point Rear wheel cylinder cylinder wheel Rear pressure to Rear wheel cylinders Master cylinder pressure Spring Repeating in Contact Piston (1/1)
  35. Diagnosis Technician >> Brake >> Brake System Proportioning Valve Operation 4.Operation when the pedal is released Cylinder cup from Master cylinder Piston Spring to Rear wheel cylinders (1/1)
  36. Diagnosis Technician >> Brake >> Brake System Proportioning Valve Types of P Valve 1.Dual P Valve/ 2.Proportioning & Dual P valve P & Bypass valve Bypass Valve (P & BV) Master cylinder Air Dual P.valve chamber P & BV Passage (opened) Spring Piston Cylinder cup Piston No.2 Piston No.1 Spring Front Front (1/2)
  37. Diagnosis Technician >> Brake >> Brake System Proportioning Valve Types of P Valve 3. Load Sensing Proportioning Valve LSPV (LSPV) LSPV Control the effectiveness Out line Split points . pressure . fully loaded Veh to Rear wheel hydr Cylinder cup cylinder from Master Vehicle unloaded cylinder Piston Rear wheel cylinder cylinder wheel Rear Valve Master cylinder (front wheel cylinder) seal hydr. pressure Valve body Extends Load-sensing spring Cross section (2/2)
  38. Diagnosis Technician >> Brake >> Brake System Foot Brake Disc Brake 1.Construction/ 2.Operation Before operation (1) Disc brake caliper (1) Disc brake caliper (5) Fluid (4) Piston (2) Disc brake pad (3) Disc brake rotor During operation (1/6)
  39. Diagnosis Technician >> Brake >> Brake System Foot Brake Disc Brake 3.Brake Adjustment Piston seal changes shape as Piston seal returns piston by piston moves. amount of its deformation. Disc brake caliper Clearance Piston Amount of Amount Disc brake pad deformation or return Disc brake rotor Brakes applied Brakes released (2/6)
  40. Diagnosis Technician >> Brake >> Brake System Foot Brake Disc Brake 4.Decrease in brake fluid Reservoir tank Piston Master cylinder Disc brake pad Brakes pad wear After pad wear (3/6)
  41. Diagnosis Technician >> Brake >> Brake System Foot Brake Disc Brake 5.Pad wear indicator Direction of disc brake rotor rotation Pad wear indicator Pad wear indicator Backing plate Disc brake pad Anti-squeal shim Before pad wear After pad wear Inner pad Pad wear indicator to ECU ECU ECU Clip Pad wear indicator Before pad wear After pad wear (4/6)
  42. Diagnosis Technician >> Brake >> Brake System Foot Brake Disc Brake 6.Types of disc brake caliper Fixed caliper type Floating caliper type Hydraulic Disc brake pressure caliper Torque plate Pin Disc brake pads Disc brake rotor Steering knuckle (Fixed) FS type AD type PD type Torque plate Pin Torque plate Bolt Pin Inner pad Disc brake caliper Disc brake Bolt Disc brake caliper Pin caliper Torque plate Bolt (5/6)
  43. Diagnosis Technician >> Brake >> Brake System Foot Brake Disc Brake 7.Types of disc brake rotor with Drum type Solid type Ventilated type HINT: Fading (6/6)
  44. Diagnosis Technician >> Brake >> Brake System Foot Brake Drum Brake 1.Construction/ 2.Operation (6) Piston (7) Piston cup (1) Wheel cylinder (2) Brake shoe (5) Brake drum (3) Brake lining (4) Return spring (1/4)
  45. Diagnosis Technician >> Brake >> Brake System Foot Brake Drum Brake 3.Leading shoe and trailing shoe Wheel cylinder Direction of drum rotation Self-energing function Leading shoe Trailing shoe (2/4)
  46. Diagnosis Technician >> Brake >> Brake System Foot Brake Drum Brake 4.Types of the drum brake Fixed wheel cylinder Fixed wheel cylinder Fixed wheel cylinder Fixed anchor Two-Leading type Leading-and-trailing type Fixed wheel cylinder Fixed wheel cylinder Adjusting cylinder Adjusting cylinder Uni-servo type Duo-servo type Forward Backward Leading shoe Trailing shoe (3/4)
  47. Diagnosis Technician >> Brake >> Brake System Foot Brake Drum Brake Fixed wheel cylinder Fixed wheel cylinder Fixed wheel cylinder Fixed anchor Two-Leading type Leading-and-trailing type Fixed wheel cylinder Fixed wheel cylinder Adjusting cylinder Adjusting cylinder Uni-servo type Duo-servo type Forward Backward Leading shoe Trailing shoe (3/4)
  48. Diagnosis Technician >> Brake >> Brake System Foot Brake Drum Brake 5.Clearance Adjustment (1) Auto adjustment type (2) Manual adjustment type HINT: Brake Pedal Height Adjustment (4/4)
  49. Diagnosis Technician >> Brake >> Brake System Foot Brake Drum Brake Adjust lever shoe lever Adjustor Adjust lever Gap is larger Adjustor Brake shoe Adjust lever Drum Adjustor Gap between shoe and drum is larger The adjust lever turns the adjustor (4/4)
  50. Diagnosis Technician >> Brake >> Brake System Foot Brake Drum Brake Expand Contract (4/4)
  51. Diagnosis Technician >> Brake >> Brake System Parking Brake Types of Parking Brake Lever 1.Lever type/ 2.Stick type/ 3.Pedal type Lever type Stick type Pedal type Release lever Parking pedal Parking pedal Lock Release HINT: Parking Brake Lever Travel Adjustment (1/1)
  52. Diagnosis Technician >> Brake >> Brake System Parking Brake Types of Parking Brake Body Drum brake type Disc brake type Brake shoe Brake shoe Shoe lever Piston Parking brake cable Disc brake pad Parking brake cable Shoe lever Devoted parking brake type Center brake type Shoe lever Brake shoe Brake shoe Parking brake cable Disc brake pad (1/1)
  53. Diagnosis Technician >> Brake >> Brake System Parking Brake Types of Parking Brake Body 1.Foot brake sharing type Drum brake type Disc brake type Brake shoe Brake shoe Shoe lever Piston Parking brake cable Disc brake pad Parking brake cable Shoe lever Devoted parking brake type Center brake type Shoe lever Brake shoe Brake shoe Parking brake cable Disc brake pad (1/1)
  54. Diagnosis Technician >> Brake >> Brake System Parking Brake Types of Parking Brake Body 2.Devoted parking brake type Drum brake type Disc brake type Brake shoe Brake shoe Shoe lever Piston Parking brake cable Disc brake pad Parking brake cable Shoe lever Devoted parking brake type Center brake type Shoe lever Brake shoe Brake shoe Parking brake cable Disc brake pad (1/1)
  55. Diagnosis Technician >> Brake >> Brake System Parking Brake Types of Parking Brake Body 3.Center brake type Drum brake type Disc brake type Brake shoe Brake shoe Shoe lever Piston Parking brake cable Disc brake pad Parking brake cable Shoe lever Devoted parking brake type Center brake type Shoe lever Brake shoe Brake shoe Parking brake cable Disc brake pad (1/1)
  56. Diagnosis Technician >> Brake >> Brake System Brake Booster Tandem Brake Booster No.2 piston Intake manifold No.1 piston Air Variable pressure chamber Constant pressure chamber (1/1)
  57. Diagnosis Technician >> Brake >> Brake System Brake Booster Fading 0.6 )  0.5 0.4 0.3 0.2 0.1 Coefficient friction ( friction Coefficient 0 100 200 300 400 500 Temperature ( C) (1/1)
  58. Diagnosis Technician >> Brake >> Brake System Foot Brake Brake Pedal Height Adjustment Pedal height Pedal freeplay Adjusting point Lock nut Push rod (1/1)
  59. Diagnosis Technician >> Brake >> Brake System Parking Brake Parking Brake Lever Travel Adjustment Lever type Lock nut Adjusting nut Stick type Adjusting nut Lock nut Adjusting nut Lock nut (1/1)