DE4236517A1 - Hydraulic actuation arrangement for a vehicle roof - Google Patents

Description

The invention relates to a hydraulic actuation arrangement for a Vehicle roof, with at least one cylinder / piston acting on the roof Arrangement of their work spaces via hydraulic lines with a switchable Pump connected.

Actuating arrangements of the type mentioned are known and enable taking advantage of the known advantages of hydraulic working cylinders easy application of larger forces in a relatively small space, what especially when used for a vehicle roof according to the mostly very limited there for the operation of the hood Space is advantageous. Through what is usually provided Switchover valve and the pump switchable in their direction of delivery result simplest conditions for the control of the actuation arrangement, usually apart from the one or the directly or indirectly on Working cylinder (s) attacking the convertible top only one, the pump valve and pressure relief valves, if necessary, emergency actuating device tions and the like comprehensive pump carrier and the connecting Hydraulic lines are to be accommodated.

Especially with the top used more and more recently arrangements in which, for reasons of space, a covered accommodation of the open convertible top in a corresponding receiving area of the vehicle is dispensed with, results in the previously known actuation arrangements always problems due to the open, more or less towards collapsible convertible roof. As a result of driving the ride winds over the open interior of the vehicle can lead to the open top is subjected to a force acting in the closing direction, which leads to a partial closing of the convertible top, which at least with higher driving speeds can cause serious problems.

Apart from the possibility to mecha the roof when open niche, for example, with snap fasteners, hooks and eyes, and the  to keep the same, which of course affects the ease of use so far essentially only on the hydraulic obstruction of the cylinder / piston ben arrangements familiar with the top open, which arises when the pump not promoting, since the changeover valve separates both sides. Stay with it However, the rod and piston side of the cylinder / piston Arrangement (s) due to the inevitable leakage in the pump and in the um switching valve connected or opened, so that the respective top especially in the case of longer-acting forces disadvantageously close in part.

Apart from the mechanical methods of holding down mentioned the soft top itself may still be an obvious solution the use of so-called lockable cylinders, in which the piston or the piston rod mechanically in at least one defined position compared to the cylinder is definable, which is a total high design effort and also the control or operation makes the actuating arrangement more complicated and therefore more prone to failure.

The object of the present invention is a hydraulic actuator to improve the arrangement of the type mentioned so that the above Disadvantages of the known or obvious arrangements can be avoided and that in particular be ensured in the simplest possible way can that the open top not unintentionally by the wind or other correspondingly acting forces can be partially closed.

This task is the hydraulic actuator assembly initially mentioned type solved in that in the hydraulic line to that Convertible top-opening work space, a check valve is arranged, the Non-return function is canceled when the convertible top is closed hydraulically. Thus the cylinder, or at least one of them, will attack the convertible top the cylinder / piston arrangement (s) when parking the roof Running pump kept under pressure via the check valve, being practical  table no leaks of the type described above can occur and a secure hydraulic lock of the open top position ensured is. The kickback is used for the normal hydraulic closing of the convertible top Function of the check valve on suitable, in two advantageous variants way described below, so that a practically unhindered Flow of the hydraulic medium from the respective cylinder chamber ensured is. During the normal hydraulic opening of the convertible top, the rear blow valve flows anyway in the incomplete direction, so that overall there is no significant influence on the otherwise usual Chen operation results. The check valve is in relation to the size the entire actuation arrangement and the manageable holding forces other options mentioned at the beginning for locking the open Hood preferred because, for example, the mechanical locking of the With increasing holding forces, piston rods also correspondingly larger Installation space required, whereas the installation space for the invention provided check valve does not change.

In an actuating arrangement of the type mentioned, with at least two parallel cylinder / piston arrangements, is in a further preferred Ausge staltung the invention a common check valve before the branch of the hydraulic lines to the individual cylinder / piston arrangements net, which results in a very inexpensive and space-saving arrangement.

The check valve can according to another development of the invention designed to be hydraulically switchable and to the hydrau via a control line be connected to the work space that closes the convertible top. In order to there is no additional switching or unlocking measure at all of the check valve for the normal hydraulic closing of the convertible top, because here is the pressure applied by the pump The check valve is unlocked.

According to another advantageous development of the invention, however  also be provided that a pressure limitation parallel to the check valve Valve is provided, which from the hydraulic closing of the top a preferably adjustable pressure threshold over the check valve bridges. In this way, no separate control line is required for switching or Unlocking the check valve to be provided - as soon as the at normal closing of the top acting hydraulic pressure a certain of the Pressure relief valve exceeds the specified extent, can be bypassed of the blocked check valve the necessary overflow of the hydraulics mediums take place relatively unhindered. It also results from Switching on such a pressure relief valve still has the advantage that Pressure increases in the system, such as those found in one Sun standing vehicle can occur, can be stopped as soon as the trigger pressure given by the pressure relief valve exceeds hydraulic medium is discharged into the reservoir.

In the case of an actuation arrangement with a the pump including the changeover valve having a pump carrier is in a further embodiment of the invention Check valve and possibly the pressure relief valve in or on Integrated bellhousing, making simple, inexpensive and space-saving Arrangements are created that also with regard to maintenance and assembly no additional assembly effort compared to previous solutions.

The invention is explained in more detail below with reference to the exemplary embodiments schematically shown in the drawing. Fig. 1 shows an embodiment of a hydraulic actuation arrangement for a convertible top, not shown, installed in a vehicle and Fig. 2 shows another embodiment according to the invention.

The hydraulic actuation arrangement shown in FIG. 1 serves to open and close a convertible top installed in a vehicle, not shown here. There are two on the top or on corresponding Ver adjusting elements or the like of the top attacking cylinder / piston assemblies 1 , 2 , the piston 3 of which is adjustable by means of hydraulic medium in cylinders 4 , with the piston rods 5 or associated, not shown Elements the actual convertible top operation takes place.

The working spaces 6 , 7 of the cylinder / piston arrangements 1 , 2 are connected via hydraulic lines 8 , 9 to a switchable pump 10 , which in turn can be driven by an electric motor 11 .

The working spaces 6 pressurized when the cylinder / piston assemblies 1 , 2 are retracted are connected via the hydraulic lines 8 at a point 12 - from there the hydraulic line 8 for both cylinder / piston assemblies 1 , 2 is connected together via a pump connection 13 guided a changeover valve 14 which is connected via a suction line 15 to a reservoir 16 for hydraulic medium. The working spaces 7 pressurized when the cylinder / piston assemblies 1 , 2 are extended are connected via the hydraulic lines 9 at a point 17 - the hydraulic line 9 , which in turn is guided from there, in turn runs via a pump connection 18 to the other side of the changeover valve 14 . Both the hydraulic line 8 and the hydraulic line 9 is in the area between the switching valve 14 and the pump connection 13 or 18 with a lead to the reservoir 16 lead 19 in connection, in each of which Druckbe limit valves 20 are turned on.

From the connection point 12 of the hydraulic lines 8 a branch line 21 branches off to the reservoir 16 , in which an emergency valve 22 is inserted, which allows manual emergency operation for closing the convertible top in the event of a failure of the supply voltage for the motor 11 , for example.

In the hydraulic line 8 to the here by retracting the cylinder / Kol ben arrangements 1 , 2 the convertible top opening work spaces 6 , a switchable check valve 23 is arranged, which is connected via a control line 24 at the connection point 17 with the other work spaces 7 Hydraulic line 9 is connected, with which the check function of the check valve 23 is canceled when the working pressure acts in the hydraulic line 9 and this can also be flowed through in the otherwise blocked direction.

During normal hydraulic opening of the convertible top by retracting the pistons 3 into the position shown, the pump 10 and the changeover valve 14 are switched appropriately via the hydraulic line 8 and this (because of the lack of pressure via the control line 24 ) acts as a check but in the open Check valve 23 flowed through in the direction of hydraulic medium under pressure to the rod-side working spaces 6 - the hydraulic medium ejected from the piston-side working spaces 7 reaches the suction side of the pump 10 via the hydraulic line 9 or - if superfluous - is discharged via the discharge line 19 . With the pump 10 switched off in the open position of the convertible top (or retracted piston 3 ), the pistons 3 cannot be extended and the partial closing of the deck, for example due to the wind, because the rod-side working spaces 6 are hydraulically closed via the check valve 23 .

During normal hydraulic closing of the convertible top by extending the pistons 3, the working pressure acts on the hydraulic lines 9 on the one hand in the piston-side working spaces 7 and on the other hand via the control line 24 on the check valve 23 thus unlocked. Thus, the hydraulic medium ejected from the rod-side work spaces 6 can be fed via the hydraulic line 8 to the suction side of the pump 10 , which draws in the hydraulic medium required in addition via the changeover valve 14 from the reservoir 16 .

Dash-dotted lines and designated 25 here is a pump carrier, which receives the pump 10 together with the motor 11 , the switching valve 14 , the two pressure relief valves 20 , the emergency valve 22 , the check valve 23 and the reservoir 16 , so that the entire actuating arrangement essentially only This pump bracket 25 , the two cylinder / piston assemblies 1 , 2 and the hydraulic lines 8 , 9 and is therefore easy to assemble or accommodate in the vehicle.

In the representation of a further embodiment according to the invention according to FIG. 2, the same or functionally identical parts are also provided with the same reference numerals - in order to avoid repetition, reference is therefore made to the above explanations for FIG. 1 with regard to these components and the corresponding functional description.

The only significant change as shown in FIG. 1 is not formed piloted and switched off at the embodiment according to FIG. 2, the check valve 23, thereby also no separate control line from the point (17 and the hydraulic line 9 as shown in FIG. 1 starting) is necessary. To enable the reversal of the check function of the check valve 23 during normal hydraulic closing of the convertible top, a pressure relief valve 26 is provided here in parallel with the check valve 23 , which bypasses the check valve 23 during the process of normal hydraulic closing of the convertible top from a preferably adjustable pressure threshold. This pressure threshold will usually be set so high that only the working pressure of the system acting when the pump 10 is running will exceed it - apart from that, the pressure threshold could also be set lower if necessary, which may even make the emergency valve 22 superfluous, since then when closing manually of the convertible top (if the working pressure fails), only this threshold would have to be overcome, which of course would have to be above a pressure threshold which would enable the convertible top to be partially closed by the wind to ensure the function intended within the scope of the invention.

Apart from the versions shown with a common back Impact valve for the work spaces opening the top could of course also individual check valves for each cylinder / piston arrangement and  if necessary, can also be provided separately for each of the two work rooms, which, however, increases the design effort again.

Claims (5)

1. Hydraulic actuating arrangement for a vehicle roof, with at least one cylinder / piston arrangement acting on the roof, the work rooms of which are connected via hydraulic lines to a switchable pump, characterized in that in the hydraulic line ( 8 ) to the working space opening the roof ( 6 ) a check valve ( 23 ) is arranged, the check function is canceled when the convertible top is hydraulically closed. 2. Actuating arrangement according to claim 1, with at least two parallel cylinder / piston arrangements, characterized in that a common check valve ( 23 ) before the branch ( 12 ) of the hydraulic lines ( 8 ) to the individual cylinder / piston arrangements ( 1 , 2nd ) is arranged. 3. Actuating arrangement according to claim 1 or 2, characterized in that the check valve ( 23 ) is designed to be hydraulically switchable and is connected via a control line ( 24 ) to the hydraulic line ( 9 ) to the working space ( 7 ) which closes the convertible top. 4. Actuating arrangement according to claim 1 or 2, characterized in that parallel to the check valve ( 23 ) a pressure relief valve ( 26 ) is seen before, which bridges the check valve ( 23 ) when the convertible top is hydraulically closed from a preferably adjustable pressure threshold. 5. Actuating arrangement according to one of claims 1 to 4, with a pump including the switch valve having pump support, characterized in that the check valve ( 23 ) and possibly the pressure relief valve ( 26 ) is integrated in or on the pump support ( 25 ).