FixVault

The Hydraulic System

Fig 1: Hydraulic System Overview
GLL154734Courtesy of VOLVO CARS CORPORATION
  1. Lock cylinder, front roof
  2. Roof cylinder, left
  3. Roof cylinder, right
  4. Main cylinder, left
  5. Main cylinder, right
  6. Lock cylinder rear roof, left
  7. Lock cylinder rear roof, right
  8. Cylinder tonneau cover, left
  9. Cylinder tonneau cover, right
  10. Cylinder trunk lid, left
  11. Cylinder trunk lid, right
  12. Hydraulic pump
  13. Splitter box, hydraulic hoses

The hydraulic system consists of:

All hydraulic cylinders are dual-acting cylinders with single-sided piston rod. The hoses are attached with quick-release couplings.

The hydraulic cylinders operate the various roof functions independently and in pairs.

Hydraulic fluid is distributed from the splitter box to the hydraulic cylinders for the tonneau cover and the cargo compartment.

WARNING:

Only used hydraulic oil intended for this hydraulic system.

Hydraulic unit 

Fig 2: Hydraulic Unit
GLL154735Courtesy of VOLVO CARS CORPORATION
  1. Electric motor that drives the hydraulic pump
  2. Housing
  3. Fluid reservoir
  4. Relief valve
  5. Lock for relief valve
  6. Electrically operated hydraulic valve (x4)
  7. Cable for release of relief valve lock
  8. Hydraulic hoses

The hydraulic unit is located in the cargo compartment underneath the ski hatch. The convertible roof module (CRM) regulates the electric motor that drives the hydraulic pump clockwise or counterclockwise. The direction of rotation depends on the sequence/position of the roof during opening/closing.

The housing contains ducts through which the fluid passes to/from the hydraulic pump, to/from the four electrically controlled hydraulic valves, to/from the hydraulic cylinders and to/from the fluid reservoir.

The four hydraulic valves are integrated in the hydraulic unit and are directly connected to the convertible roof module (CRM). The various positions of the hydraulic cylinders (and thereby the positions of the roof sections) are regulated by opening/closing the valves in different patterns.

The relief valve releases pressure in the system when it is lifted. The ducts with pressure are then connected to the return ducts, whereby system pressure drops. Before the valve can be lifted, the lock (5) must first release the valve. This is done by pulling the cable. The handle of the cable is located under the rear seat cushion.

WARNING:

The roof should be closed when relieving fluid pressure so that the roof does not collapse.

The hydraulic hoses are fitted in the housing with O-rings as seals. The hoses are secured with a screw. The hoses and housing have numbering to facilitate identification.

The hydraulic unit is enclosed by a casing to reduce noise from the pump.

Hydraulic cylinders 

Fig 3: Hydraulic Cylinders
GLL152639Courtesy of VOLVO CARS CORPORATION
  1. Lock cylinder, front roof
  2. Roof cylinder, left
  3. Roof cylinder, right
  4. Main cylinder, left
  5. Main cylinder, right
  6. Lock cylinder rear roof, left
  7. Lock cylinder rear roof, right
  8. Cylinder tonneau cover, left
  9. Cylinder tonneau cover, right
  10. Cylinder trunk lid, left
  11. Cylinder trunk lid, right
  12. Hydraulic pump
  13. Splitter box hydraulic hoses

= Open

= Closed

All hydraulic cylinders are double acting cylinders with single side pistons. The piston/cylinder diameter, stroke length and mounting differ depending on task.

Roof cylinders 

The two roof cylinders open/close the front roof section. In addition, the roof cylinders lock the front roof section to the center roof section and the center roof section to the rear section.

The locking sequence is carried out after the roof closes and the unlocking sequence occurs before the roof starts to open.

Locking occurs by the lugs on the hydraulic piston engaging in a cut-out on the locking mechanism plate. This causes the catches to follow the piston movement, where the front roof section locks into the center roof section. A ball joint is secured to the plate, opposite the catches. A push rod is connected to the ball joint. When the locking mechanism's plate moves, the push rod also moves (as do the catches). The push rod then engages in the lock housing for the rear roof section whereupon the center roof section is locked to the rear roof section.

The sequence is reversed when unlocking. i. e. the roof sections are first released and then the front roof sections opens.

The lock cylinders for the front roof section, lock cylinders and cylinders cover panel. 

These cylinders move on bearings at both the cylinder and piston through ball joints. The design means that the load on these cylinders is relatively small.

Master cylinders 

The master cylinders close/open the center roof section directly via the main link arms and the rear roof section indirectly via its link arms.

The movement and geometry of the link system when opening and closing the roof, cause the pistons to move elliptically. The master cylinders are suspended to prevent breaks and stresses.

Cylinders, trunk lid 

The cylinders for the trunk lid are exposed to relatively large forces and are therefore strongly dimensioned. The cylinders move on bearings via bolts at both the piston and cylinder.

Connection of the hydraulic hoses to the pump 

Fig 4: Connection Of The Hydraulic Hoses To The Pump
GLL152636Courtesy of VOLVO CARS CORPORATION

F1 - F4 = hydraulic valves.

Connection of the hydraulic hoses to the splitter box 

Fig 5: Connection Of The Hydraulic Hoses To The Splitter Box
GLL153256Courtesy of VOLVO CARS CORPORATION