DE19527494A1 - Pneumatic operating device to connect snowplough to public service vehicle - has air pressure line leading from vehicle to pneumatic=hydraulic pressure converter and hydraulic line leading to cylinder - Google Patents

Abstract

The device has at least one pressure cylinder (19) and one other, independent cylinder (23) and is linked via an air pressure connection to the air pressure system of a public service vehicle. The second cylinder performs a rotating action. The air pressure inlet of at least one pneumatic-hydraulic pressure converter (25',25'') is connected to the air pressure line (27) leading to the vehicle's air pressure system. A change-over/shut-off valve (29) is fitted between the vehicle and converter. A hydraulic line (33',33'') leads from the converter outlet to at least one pressure chamber of the hydraulic cylinder. A change-over/shut-off valve is fitted between converter and cylinder.

Description

The invention relates to a mountable on a vehicle pneumatic actuator, especially one attachable to a commercial vehicle and pneumatically operated Plow according to the preamble of claim 1.

Usually can be attached to commercial vehicles Plows, d. H. Snow plows over the on the commercial vehicle hydraulic circuit operated and controlled.

However, there are also known commercial vehicles that come from the house only equipped with an air pressure circuit on the vehicle side are. To grow and operate a snow plow here has already been suggested the lifting cylinder of the plow, which can be attached at the front, be lifted pneumatically and lower. The pivoting of the ploughshare can al lerdings always only be carried out hydraulically in order Clearing operation optimally absorbs the clearing forces Preserve the preset swivel position hold. Therefore in such a case at least  for actuating the pivoting device of the ploughshare a hydrau designed at least for this application lica system can be retrofitted on the vehicle.

It is therefore an object of the present invention based on the above-mentioned prior art serial actuating device that can be attached to a vehicle, in particular an improved pneumatically driven Actuating device for a on a commercial vehicle attachable plow to create that without vehicle-side Retrofitting a hydraulic pressure system pneumatically is done, and yet with conventional actuating device working by means of hydraulic medium gene / plowing is comparable.

The task is according to the invention in accordance with saying 1 or the features specified in claim 9 ge solves. Advantageous embodiments of the invention are shown in specified in the subclaims.

The invention makes it possible in particular with so-called called entrepreneurial vehicles - at most with a Air pressure system are equipped on the vehicle - the same probably attaching a snow plow to the front, for example and operate pneumatically. Thereby a tax behavior of the snow plow in particular allows its pivoting, which is comparable with control systems by means of hydraulic medium controlled swivel cylinders.

According to the invention, a subsequent part of this is also as Pneumatic-hydraulic pressure converter designated air pressure Oil pressure conversion element provided that plows in is installed. The air provided by the vehicle pressure propagates into the hydraulic medium. The Ver The ploughshare is then pivoted over at least one  Hydraulic cylinder accomplished, after reaching the desired pivot position via a switch lock valve of the at least one hydraulic cylinder is locked. So there is a hydraulic cylinder for the actual implementation the pivoting with an incompressible liquid Medium (hydraulic oil etc.) is used as a result for the ploughshare a firm and rigid lock in ensures the desired pivot position, ver comparable to conventional hydraulically operated snow plows When using a pneumatic cylinder for the ver otherwise the ploughshare would be the problem stand that the plow due to the clearing operation the compressibility of the air, especially when starting off "Obstacles" would begin to "swim".

In a further development of the invention, it is also provided hen that at least one air pressure-oil pressure converter sionselement another change-over check valve is what the conversion element of the vehicle is about side air pressure connection can be disconnected. Here become in a further development of the invention this at least one switchover upstream of the conversion element Check valve and that between the conversion element and the at least one hydraulic cylinder provided Change-over check valve actuated simultaneously.

In a development of the invention it is provided that two air pressure-oil pressure conversions connected in parallel elements are provided, their hydraulic pressure output with the two pressure chambers at least one hydraulic cylinder or in connection with each other Pressure chamber of at least two hydraulic cylinders provided.

It has also proven to be particularly favorable if preferably on the ploughshare side, ie preferably on the part of the attachable actuator, another air pressure  Storage is provided, which increases the volume of the air pressure containers usually provided on the vehicle ters serves. This ensures that also the additionally connected consumers are always sufficient the problematic operating pressure can be supplied.

Finally, overpressure safety valves can be used as usual be provided, which are preferably in the hydraulic lines are switched, via which a connection if necessary from the relevant hydraulic pressure chamber of the hydraulic cylinder Lindner to the conversion element bypassing the da Intermediate changeover check valve can be produced is.

In an alternative embodiment of the invention is before seen that the actuator, especially the Ploughshare for swiveling at least one or preferably two pneumatically actuated pivoting has cylinder. In this case, however, is then also an additional locking device for actuate the ploughshare and / or the relevant pneumatically actuable cylinder (e.g. the ploughshare Swivel cylinder) provided to the swivel device mechanically rigid in the selected swivel position so as not to lock "floating".

The mechanical locking device can be manu ell or preferably actuated. It is a solution is also possible in which the pneumatic actuatable swivel cylinders with an integrated Locking device is provided that automatically after switching off the pressure (i.e. after closing the changeover check valve upstream of the pressure chamber) automatically switches back to the locked position and the cylinder and pistons when air pressure is applied rod releases again.  

The invention also offers particularly advantageous Way a cheap way to use a pneumatic plow provide relief with. This would just go over for example, a pressure that can be set from the cab reducing valve can be controlled, which for example before the pneumatic lifting cylinder could be installed.

The invention is explained below with reference to exemplary embodiments play explained in more detail. Show in detail

Fig. 1 is a schematic circuit arrangement of a first embodiment of the invention;

Fig. 2 is a modified to Figure 1 execution example;

Fig. 3 is a schematic excerpt of a sectional view through one end of a pneumatically operable cylinder with inte grated actuatable entanglement device;

Fig. 4 shows a modified embodiment egg ner exclusively pneumatic actuation device with an additional mechanical locking mechanism; and

Fig. 5 is a schematic partial cross-sectional view for explaining a Pneumaticzylin equipped with an integrated locking device.

In Fig. 1, a first embodiment of a circuit arrangement for an actuating device is shown, namely for operating a snow plow attachable to a commercial vehicle.

From the representation according to FIG. 1, the components required for the operation of the plow on the vehicle are provided with components I and the components on the plows side are marked with II and separated by a dashed line.

On the vehicle side, a corresponding air compression device 1 is provided, which is usually operated via the drive machine provided on the vehicle and a downstream compressor unit. The air compression unit includes - as indicated schematically in Fig. 1 - an air pressure container 3 , which is always sufficient to maintain the air pressure via the air pressure compression device.

Furthermore, a so-called four-circuit protection valve 7 can also be provided on the vehicle-side air pressure lines 14 , but this is essentially irrelevant for the following explanation of the operation of the ploughshare.

When the ignition lock 9 is actuated, plug contacts provided at the interface 11 between the vehicle and the add-on unit can subsequently be used to operate the plow in the manner explained in detail below.

It is indicated that the plowshare-side Luftdrucklei device 13 , which can be connected to the interface 11 via a corre sponding air pressure connection to the vehicle-side air pressure line 14 , leads to a first switch-over valve 15 , at the output of two air pressure control lines 17 ', 17 ''Leads to the two pressure or working spaces of a first pneumatically actuated lifting cylinder 19 . By appropriately switching the change-over check valve 15 , the pneumatic lifting cylinder 19 can be raised or lowered and, for example, locked in the raised position and be depressurized in the lowered position. To operate the snow plow, the lifting cylinder 19 is lowered to lower the snow ploughshare on the road surface. When traveling to or from the place of use, the ploughshare is lifted upwards by appropriate lifting movements of the lifting cylinder 19 and, as mentioned, the associated switch-over valve 15 is blocked. Vibrations occurring while driving can lead to a certain vibration behavior of the plow due to the compressibility of the pneumatics, but this has no other disadvantageous consequences.

The actuating device, ie the ploughshare and the associated actuating components comprises, after the exemplary embodiment according to FIG. 1, yet another hydraulically actuatable cylinder. In Fig. 1, the hydraulic cylinder is provided with the reference numeral 23 .

In order to pivot the ploughshare from left-hand clearing to right-hand clearing and vice versa or into a middle neutral position by means of this hydraulic cylinder 23, two parallel air pressure-oil pressure conversion elements 25 ', 25 ''are also provided, which usually consist of a corresponding pressure vessel, the pressure interior of which is divided into two is, a part of the pressure interior with the air pressure line system via an Luftdruckzweiglei device 27 with the interposition of a further switch-over valve 29 is in connection. It is a three-position two-way valve, which is switchable apart from a middle locking position so that the pressure side of the air pressure branch line 27 once the first conversion element 25 'and in the other switching position, the second conversion element 25 ''via a pneumatic matics line 27 'or 27 ''pressure loaded.

The second part of the pressure interior of the respective conversion element 25 is filled with a hydraulic pressure medium, usually oil. Both the air pressure chamber and the hydraulic pressure medium chamber can be separated, for example, by a flexible membrane 31 that transmits the pressure well.

On the output side, the two conversion elements 25 ', 25 ''are connected via hydraulic pressure lines 33 ' and 33 '' with an intermediate switching valve 35 (a two-position one-way valve) to the two pressure or working spaces of the downstream hydraulic cylinder 23 .

Furthermore, each hydraulic pressure line 33 ', 33' 'a positive-pressure safety valve 37, while closing the respectively associated Umschaltsperrventils 35 is connected in parallel to at impermissible overload pressure peaks the pressure and there with the hydraulic pressure medium to the upstream depending weils associated conversion element 25' and 25 ' Deduct ben.

As can also be seen from FIG. 1, a white air pressure tank 39 is also preferably provided on the ploughshare side to increase the volume, which is also connected to the air pressure line system, in the embodiment shown, with the attachment-side air pressure line 13 .

If a snow plow is to be lowered during operation and, for example, adjusted to the left, the corresponding electrical control device 41 is used to emit the corresponding control signals on the vehicle, which control the corresponding switchover valves via electrical control lines 43 and 44 .

The pneumatic lift cylinder 19 zugeord Nete changeover valve 15 (a three-position two-way valve) is switched so that the lifting cylinder 19 lowers the plow sharply.

Furthermore, the upstream of the hydraulic cylinder 23 switch-over valve 29 is switched from its blocking position into its one switching position so that, for example, the conversion element 25 on the left in FIG. 1 is pressurized with air pressure, so that the corresponding pressure on the output side is hydraulically chambered to the associated pressure of the hydraulic cylinder 23 passed on and in example the ploughshare is pivoted to the left. At the same time with the activation of the switchover valve 29 mentioned, the two switchover valves 35 provided in the two hydraulic pressure lines 23 'and 23 ''are also switched over to the open position.

After pivoting, the last two switch-over valves 35 'and 35 ''are again in their blocking position shown in Fig. 1 and the conversion elements 25 upstream switch-over valve 29 just in case switched back to the middle blocking position.

In this switching position, the hydraulic cylinder 23 is then hydraulically locked, so that a selected pivoting position remains unchanged due to the incompressibility of the liquid even when hard clearing.

If the ploughshare is pivoted to a position for eviction, the control switch valve 29 is actuated accordingly in the opposite switching position, and the switchover of the switch control valves 35 'and 35 ''to open the hydraulic pressure lines 33 ' and 33 '' is carried out at the same time to allow a reverse Schwenkbe movement of the hydraulic cylinder 23 . The changeover valves mentioned are then blocked again.

From the structure described it can be seen that the hydraulic medium flowing in the hydraulic lines 33 'to the associated Ar beits- and pressure frame in the cylinder 23 is separated from the flowing in the second pressure line 33 ''to the respective other pressure and working space in the cylinder 23 Hydraulic medium. Even when impermissible overload the pressure medium can always only from the BE taken hydraulic pressure line 'sion element associated convergence 25' 33 and 'flow from the hydraulic line 33' 'to the associated conversion element 25', so that the hydraulic volume quantities remain without changes in both sub-lines.

The switching valves for pneumatics are designed that the pressure-relieved line leads outdoors.

The embodiment of FIG. 2 differs from that of FIG. 1 inter alia in that instead of the single hydraulic cylinder 23 provided in FIG. 1, now two hydraulic cylinders 23 'and 23 ''are seen before. The two hydraulic pressure lines 33 'and 33 ''are then in communication with the respective pressure chamber of the assigned hydraulic cylinder 23 ' and 23 ''.

In particular, in this embodiment with two Ver pivot cylinders it is provided that both Verschwenkzy cylinder 23 'and 23 ''are at least indirectly mechanically gekop pelt.

Referring to Fig. 3 is further indicated that the pneumo-hydraulic pressure converter 25, so the hydraulic pressure-oil pressure conversion elements may be formed 25 by way of a Dop pelzylinders, wherein the first cylinder as a pneumatic cylinder 45 and the second obligation on downstream cylinder acts as a hydraulic cylinder 47 . As is also indicated in FIG. 3, the pneumatic piston 45 'is connected to the hydraulic piston 47 ' via a common piston rod 46 .

When pressure is applied to the corresponding piston surface of the pneumatic cylinder 45 , the pressure is then transferred via the common piston rod 46 and the hydraulic piston 47 'to the hydraulic pressure medium in the pressure chamber of the hydraulic cylinder 23 or 23 '.

The schematic representation according to FIG. 3 also shows, however, that the conversion element 25 thus constructed in the manner of a double cylinder system can simultaneously act in the sense of a force transmission. Because of the differently sized piston surfaces, once in the respective pneumatic cylinder 45 to the smaller piston surface in the hydraulic cylinder 47, there is a power transmission to higher force values in accordance with the ratio of the piston surfaces.

This is particularly advantageous if, for example, only an air pressure of 6 to 8 bar is provided on the vehicle side, which would otherwise not be sufficient. In contrast, by means of these conversion elements formed in this way or by additional connection of such translation pistons according to FIG. 2, it is possible to achieve a hydraulic pressure in the hydraulic cylinder 23 which can easily be 10 bar or more, for example 12 or 15 bar.

Referring to Fig. 4, a pneumatically operated actuator is provided, for example for raising and lowering and pivoting of left to right and vice versa evacuation of a ploughshare.

In this case, the air pressure control system is no longer only connected to the pneumatically actuated lifting cylinder 19 , but also, for example, to the one (or more provided) pneumatically actuated pivoting cylinders 49 . The pressure-relieved pressure chamber 50 of the two pivoting cylinders 49 is connected via a common line 52 and a switch-over blocking valve 54 to the line 27 pressurized actually. When pressure is applied to the cylinder 49 via the lines 27 , 27 'and 27 '', the pressure chamber 50 is depressurized into the atmosphere via the valve 54 .

However, it is only indicated schematically here that a locking device 51 is provided in the area of the piston rod projecting above the pivoting cylinder 49 , for example, which acts mechanically and can be operated manually. After choosing a desired pivot position of the ploughshare, this manually operable locking device 51 can be tightened, so that the pivot cylinder 49 is mechanically locked.

The mechanical locking device 51 can, however, also sit at a different location of the ploughshare and act relatively at least indirectly to a vehicle-side base.

The lock 51 mentioned can be tightened and released manually. However, controllable mechanically acting locking devices 51 are also possible, which, for example, can be actuated pneumatically, electrically, etc. in order to ensure mechanical locking.

Reference to the schematic partial sectional view through a pneumatic Verschwenkzylinder 49 of FIG. 5 is shown that the pneumatically actuatable Verschwenkzy may also be provided with an integrally provided Verrie gelungseinrichtung 51 linder 49. The piston rod 57 can be locked via an integrated slope, ie wedge-shaped surface 53 and a locking member 55 that can be displaced on it at least slightly. It is known per se that the locking member 55 can be controlled, for example, elec trically or pneumatically, to move over the locking member 55 to the locking position or to the release position. The control takes place in such a way that when the pivoting cylinder 49 is pneumatically actuated (that is, when the associated pressure chamber is pressurized appropriately), the integrated locking device 51 is automatically switched to the release position and, when the compressed air line is locked, is automatically switched back to the locked position. Due to the wedge effect between the locking member 55 and the wedge-shaped support surface 53 of the counterpart, sufficiently large radial clamping forces are generated between the cylinder wall and the piston in order to mechanically lock it. The control of the locking device according to the embodiment of FIG. 5 is carried out such that the wedge-shaped brake element 55 is automatically shifted into the blocking position on the wedge-shaped surface 53 when the pressure is reduced or depressurized by means of a compression spring device 61 until the sufficient radial on the outer circumference of the Piston rod 57 acting clamping forces are so large that the piston rod locks. By pressurizing via a compressed air connection 63 , an integrated annular piston 65 can then act on the end face of the braking element 55 against the force of the compression spring 61 and move it so that the piston rod 57 can be adjusted to perform an axial movement.

Furthermore, one can also in all exemplary embodiments pneumatic plow relief provided. This can For example, one that can be set from the driver's cab Pressure reducing valve be started, which before the pneu matic lifting cylinder is realized.

Claims (13)

1. A vehicle-mountable pneumatic actuation device with preferably at least one pneumatically actuated pressure cylinder ( 19 ) and at least one sepa rat from the pressure cylinder ( 19 ) actuated further cylinders ( 23 ; 23 ', 23 ''), the actuating device via an air pressure connection the air pressure system of the vehicle can be connected, characterized by the following further features

• - The at least one further cylinder ( 23 ; 23 ', 23 '') be consists of a hydraulic cylinder ( 23 ; 23 ', 23 ), preferably serving as a pivoting cylinder,
• - At least one pneumatic-hydraulic pressure converter ( 25 ) is provided,
• - The pneumatic-hydraulic pressure converter ( 25 ; 25 ', 25 '') is connected on the air pressure input side to the air pressure system ( 55 , 27 ) leading to the vehicle-side air pressure system;
• - The at least one pneumatic-hydraulic pressure transducer ( 25 ; 25 ', 25 '') is connected to the pressure output side via a hydraulic line ( 33 ', 33 '') with at least one pressure chamber of the hydraulic cylinder ( 23 ; 23 ', 23 '') ,
• - In the hydraulic line ( 33 ; 33 '') leading from the pneumatic-hydraulic pressure converter ( 25 ; 25 ', 25 '') to the hydraulic cylinder ( 23 ; 23 ', 23 '') there is a change-over check valve ( 35 ', 35 '') for hydraulic locking of the hydraulic cylinder ( 23 ; 23 ', 23 '') provided and
• - It is one of the at least one pneumatic-hydraulic pressure transducer ( 25 ; 25 ', 25 '') upstream change-over check valve ( 29 ) for pressurizing or blocking and / or for depressurizing the pneumatic-hydraulic pressure transducer ( 25 ; 25 ', 25 '') upstream.

2. Actuating device according to claim 1, characterized in that at least two parallel connected pneumatic hydraulic pressure transducers ( 25 ', 25 '') are provided, the pressure output side of which each have a separate hydraulic pressure line ( 33 ', 33 '') and a provided in each hydraulic line ( 33 ', 33 '') changeover check valve ( 35 ', 35 '') to the first or second pressure chamber of the at least one hydraulic cylinder ( 23 ; 23 ', 23 '') are connected. 3. Actuating device according to claim 1, characterized in that at least two parallel connected pneumatic hydraulic pressure transducers ( 25 ', 25 '') are provided, the pressure output side of which each have a separate hydraulic pressure line ( 33 ', 33 '') and a provided in each hydraulic line ( 33 ', 33 '') changeover check valve ( 35 ', 35 '') are each connected to the associated pressure chamber of at least a first and a second hydraulic cylinder ( 23 ', 23 ''). 4. Actuating device according to one of claims 1 to 3, characterized in that to the respective switch-off valve ( 35 ', 35 '') this switch-over valve ( 35 ', 35 '') bridging overpressure safety valve ( 37 ', 37 '') connected in parallel and connected to the hydraulic line ( 33 ', 33 ''). 5. Actuating device according to one of claims 1 to 4, characterized in that an air pressure container ( 39 ) is connected on the attachment side to the air pressure line system ( 55 , 27 ) provided there. 6. Actuating device according to one of claims 1 to 5, characterized in that the at least one pneumatic-hydraulic pressure transducer ( 25 ; 25 ', 25 '') upstream changeover check valve ( 29 ) and in the downstream hydraulic pressure lines ( 33 ' , 33 '') vorgese hen reversing check valves ( 35 ', 35 '') can be reversed simultaneously or at least almost simultaneously from their blocking position into their open position and vice versa. 7. Actuating device according to one of claims 1 to 6, characterized in that a force booster is provided to increase the pressure prevailing in the hydraulic system against the pneumatic pressure, the pressure booster being part of the pneumatic-hydraulic pressure transducer ( 25 ). 8. Actuating device according to one of claims 1 to 6, characterized in that a force booster is provided to increase the pressure prevailing in the hydraulic system against the pneumatic pressure, the respective pneumatic-hydraulic pressure transducer ( 25 ', 25 '') before or is preferably connected downstream. 9. A vehicle-mountable pneumatic actuating device with preferably at least one pneumatically actuated pressure cylinder ( 19 ) and at least one sepa rat actuatable by the pressure cylinder ( 19 ) actuated further cylinder ( 23 ; 23 ', 23 ''), the actuating device via an air pressure connection the air pressure system of the vehicle is weldable, characterized by the following features

• - The at least one further cylinder is also designed as a pneumatic cylinder ( 49 ), and
• - At least one mechanical locking device ( 51 ) is provided, via which the at least one further pneumatic cylinder ( 49 ) can be mechanically locked.

10. Actuating device according to claim 9, characterized in that the mechanical locking device ( 51 ) can be switched manually from its locking position to its release position and vice versa. 11. Actuating device according to claim 9, characterized in that the mechanical locking device ( 51 ) can be controlled from its locking position to its release position and vice versa, preferably electrically and / or pneumatically reversible. 12. Actuating device according to claim 9 or 11, characterized in that the mechanical locking device ( 51 ) as in the at least one Pneumatikzy cylinder ( 49 ) integrated locking device is executed. 13. Actuating device according to one of claims 1 to 12, characterized in that a pneumatic attachment relief, in particular a pneumatic plow relief is also provided on the installation side, which is preferably controllable via a pressure regulator valve switched in front of the pneumatic cylinder ( 19 ), which in turn can be controlled is preferably adjustable from the cab.