SWITCHABLE HYDRAULIC LASH ADJUSTER (SWITCHABLE HLA), ROCKER ARM [SKYACTIV-G (WITH CYLINDER DEACTIVATION (E))]

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Purpose, Function

Switchable HLA

• The switchable HLA maintains the valve clearance at a constant 0 mm {0 in} to achieve a maintenance-free valve clearance.

• With the adoption of the switchable HLA, the intake/exhaust valve operation is stopped and cylinder deactivation is achieved.

Rocker arm

• With the adoption of the rocker arm and built in needle roller bearing, the contact to the cam employs rolling contact to reduce sliding resistance.

Construction

Switchable HLA

• The switchable HLAs are installed to the cylinder head on the upper part of the No.1 and No.4 cylinders.

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• The switchable HLA consists of the following parts.

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Rocker arm

• The rocker arm is installed to the switchable HLA and the top of the valve.

• The needle roller bearing is built into the rocker arm.

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Operation

• The plunger presses up the rocker arm to maintain the valve clearance at 0 mm {0 in}.

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Cylinder deactivation is not performed

1. When the hydraulic pressure applied to the lock piston is low, the lock piston attaches to the outer housing.

2. The pivot point of the rocker arm switches from the valve to the switchable HLA in Step 1.

3. When load is applied, the valve is pressed in.

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During cylinder deactivation

1. When the hydraulic pressure applied to the lock piston is high, the lock spring compresses and the lock piston is pressed into the inner housing.

2. The pivot point of the rocker arm switches from the switchable HLA to the valve in Step 1.

3. When load is applied, the inner housing with plunger is pressed in.

Note

• Because the load of the lost-motion spring is lower than the load of the valve spring, the inner housing with plunger are pressed in. Due to this, the valve does not operate.

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