دليل الخبراء: FAW Logic Assembly For The Valve Train for the CA4251P66K24T1A3E5 Tractor

مرحبًا بك في هذا الدليل الفني المتخصص حول تجميع منطق FAW لقطار الصمام, الكامل “top-end” actuation system for the FAW Jiefang CA4251P66K24T1A3E5 6×4 جرار نصف مقطورة ديزل. This is the most complex assembly of moving parts in the engine.

ال تجميع منطق FAW لقطار الصمام (أو “valvetrain”) contains every component responsible for translating the camshaft’s rotation into the precise opening and closing of all 24 صمامات المحرك. هذا النظام “منطق” dictates the engine’s entire breathing and braking performance.

يعد هذا الدليل مصدرًا أساسيًا لمحترفي إعادة بناء المحركات, محلات الآلات, والفنيين. سنقوم بتفكيك الكل تجميع منطق FAW لقطار الصمام, including every rocker arm, صمام, ربيع, seat, ختم, كوبري, and solenoid, breaking it down to its smallest serviceable unit.

The Rocker Arm Assemblies and Blocks

The core of the actuation system within the تجميع منطق FAW لقطار الصمام is the rocker arm set. The parts list details an ‘Intake rocker arm assembly’ (1007110-51ب) and an ‘Exhaust rocker arm assembly’ (1007120-51ب), with six of each for the six-cylinder engine. These are the levers that the camshaft lobes act upon.

These are not simple levers; they are complex assemblies, likely featuring a roller-follower at the point of contact with the cam to reduce friction and wear. This roller is a high-wear item, and its integrity is key to the health of the تجميع منطق FAW لقطار الصمام. The other end of the arm is designed to press on the valve bridge, actuating two valves at once.

The rocker arms are supported by a shaft that is held in place by a series of ‘Rocker arm blocks’. The parts list shows a very specific set: ‘Rocker arm block (واحد)’ (1007181-81د), ‘Rocker arm block (اثنين)’ (1007182-51ب), ‘Rocker arm block (واحد, اثنين, ثلاثة)’ (1007165-51ب), ‘Rocker arm block (ثلاثة)’ (1007183-51ب), and ‘Rocker arm block (أربعة, خمسة, ستة)’ (1007175-51ب). This highly specific, non-interchangeable set of blocks forms the bearing saddles for the rocker arm shaft, ensuring its perfect alignment over the cylinder head. هذه الكتل, along with the ‘Rocker arm shaft locating sleeve’ (1007163-51ب), are fundamental to the rigid structure of the تجميع منطق FAW لقطار الصمام.

The 4-Valve Actuation: Bridges and Tappets

This engine uses a four-valve-per-cylinder design (two intake, two exhaust), but only has a single camshaft. ال “منطق” that allows one rocker arm to actuate two valves is the “valve bridge.” ال تجميع منطق FAW لقطار الصمام includes six ‘Intake valve bridge’ (1007012-81د) and six ‘Exhaust valve bridge assembly’ (1007015-81د) وحدات.

A valve bridge (or yoke) هو صغير, precise T-shaped component that sits on top of the two valve stems for a single port (على سبيل المثال, the two intake valves). The rocker arm presses on the center of the bridge, which then transfers this force evenly to both valves, pushing them open in perfect synchrony. The ‘Exhaust valve bridge assembly’ is likely more complex, possibly containing a mechanism related to the engine brake.

The parts list also includes 48 ‘Valve block’ (1007028-53د) وحدات. This quantity (48 = 24 valves x 2) is initially confusing. لكن, these are likely the hardened steel “غمازات” أو “caps” that sit on the very tip of the valve stems. The valve bridge’s adjuster screws press on these tappets, not the valve stem itself. وهذا يوفر دائم, replaceable wear surface, protecting the valve stem. The proper function of these small components is essential for the entire تجميع منطق FAW لقطار الصمام to operate correctly.

Solenoid Valve (1007164-51ب): The Engine Brake Logic

A key feature of this تجميع منطق FAW لقطار الصمام is the ‘Solenoid valve’ (1007164-51ب), منها اثنان. In a heavy-duty diesel, a solenoid in the valvetrain almost invariably controls the engine brake (على سبيل المثال, أ “جيك بريك”). This solenoid is an electronically controlled valve that manages the flow of high-pressure engine oil.

When the driver activates the engine brake, this solenoid opens, directing oil to a special hydraulic circuit within the تجميع منطق FAW لقطار الصمام (likely integrated into the rocker arms or exhaust bridges). This hydraulic pressure overcomes the valve spring and forces the exhaust valves to open at the *top* of the compression stroke, right *before* the fuel injection stroke.

This action releases the highly compressed air (زيادة 500 رطل لكل بوصة مربعة) from the cylinder, dissipating the energy as noise (the classic “جيك بريك” صوت) instead of pushing the piston back down. The engine is effectively turned into a giant, power-absorbing air compressor, which provides significant braking force without using the service brakes. This solenoid is the electronic “مخ” of the braking side of the تجميع منطق FAW لقطار الصمام. It is protected by a ‘Solenoid valve cover assembly’ (1007160-51ب) and sealed with ‘Copper gaskets’ (س/WC3403-94(8X14)).

The Complete Valve & Spring System

هذا تجميع منطق FAW لقطار الصمام list is a complete kit, as it includes the valves themselves: 12 ‘Intake valve’ (1007011-81د) و 12 ‘Exhaust valve’ (1007016-81د). The intake valve has a larger head to maximize airflow *in*, while the exhaust valve has a smaller head and is made of a superior high-temperature alloy (like Inconel or a sodium-filled stem) to survive the 700°C+ exhaust gases.

These valves are sealed against the head by the ‘Intake valve seat’ (1003012-81د) and ‘Exhaust valve seat’ (1003013-81د). These hardened steel rings are pressed into the cylinder head and are the replaceable “wear surface” that the valve seals against. هذا بأكمله تجميع منطق FAW لقطار الصمام is designed to be fully serviceable.

The valves are kept closed by a complex set of springs. The list shows ‘Intake valve spring’ (1007021-81د) and ‘Exhaust valve inner spring’ (1007023-81د). This is a critical detail. The exhaust valve likely uses *two* springs (an inner and an outer, though the outer isn’t listed here) for added pressure. This dual-spring setup is crucial to prevent “valve float” on the exhaust side, where high-RPM exhaust pulses can literally “blow” the valve open, destroying the timing. These springs sit on the ‘Valve spring seat’ (1007024-81د), a hardened washer that protects the aluminum head.

Critical Seals: Valve Guide and Oil Seal (1007035-81د)

Two components in this تجميع منطق FAW لقطار الصمام list are responsible for sealing the valve stems. أولاً, the ‘Valve guide’ (1003014-81د), منها هناك 24, is the bronze or iron sleeve pressed into the head. The valve stem slides up and down inside this guide. This component maintains the valve’s alignment and transfers heat from the stem to the water-cooled head.

ثانية, and most critically for oil consumption, is the ‘Valve guide oil seal assembly’ (1007035-81د), مع 24 وحدات. This is a small, “umbrella-shaped” ختم, typically made of high-temperature Viton. It clips onto the top of the valve guide. Its purpose is to prevent the “bath” of oil splashing around the rocker arms from being sucked down the valve guide (between the guide and the fast-moving stem) and into the combustion chamber.

Worn valve stem seals are the number one cause of high oil consumption and blue smoke on engine startup. Replacing these 24 seals is a mandatory step in any professional rebuild of the تجميع منطق FAW لقطار الصمام to ensure a smoke-free, فعال, and emissions-compliant engine. كامل تجميع منطق FAW لقطار الصمام depends on these small seals.

FAW Logic Assembly For The Valve Train Parts List

الجدول التالي يوفر كامل, detailed breakdown of all components identified in the ‘Logic Assembly For The Valve Train’ رسم تخطيطي للجرار FAW CA4251P66K24T1A3E5. This is the complete parts group for a full top-end valvetrain service of the تجميع منطق FAW لقطار الصمام.

المواصفات الفنية وسياق التجميع

المواصفات ل تجميع منطق FAW لقطار الصمام are defined by its function as the complete 24-valve actuation and engine braking system. كامل تجميع منطق FAW لقطار الصمام is a precision-engineered system.