EP0580221A1

EP0580221A1 - Device for operating the door of vehicle door units

Info

Publication number: EP0580221A1
Application number: EP93202058A
Authority: EP
Inventors: Ermanno Righi
Original assignee: OMZ SpA
Current assignee: OMZ SpA
Priority date: 1992-07-21
Filing date: 1993-07-12
Publication date: 1994-01-26
Also published as: ITRE920060A0; IT1260120B; ITRE920060A1

Abstract

A first element (11) of the support structure (10) able to rotate about the axis of rotation (A) is fixed to the door frame (9) in a vertical direction; a second element (12) is supported by the first element (11) in a manner rotatable about the axis (A) and movable vertically relative to the element (11); said element (12) is fixed to the door (1) to move vertically therewith; a first piston is slidable under sealed conditions within a first chamber filled with operating liquid and is rigid with the support element (11); a second piston (32) is slidable under sealed conditions within a second chamber (34) filled with operating liquid and is rigid with the support element (11); said chamber (33) communicates with the chamber (34) via a passage duct (35) such that compression of the chamber (33) produces expansion of the chamber (34), the expansion of the chamber (34) causing the second piston (32) to rise relative to the chamber (34); valve means (40) are also provided to automatically close the passage (35) for the operating liquid from the chamber (34) to the chamber, said passage being able to be opened by external control.

Description

The invention relates to a device for operating the door of vehicle door units, comprising a structure rotatable about a vertical axis of rotation and operated by a fluid actuator able to move the door relative to the door aperture, in which the door is locked to the door frame by being moved upwards when in its closed position.
For this purpose, especially for doors which move roto-translationally outwards of the vehicle, it is known to provide a rotatable column which supports the door by horizontal arms and is made to rotate inwards and outwards to close and open the door respectively, by means of a fluid actuator with the aid of a screw transmission. Said column can both rotate and move axially; when the door is opened or closed the column rotates whereas when the door is in its closed position the screw transmission mechanism raises the column through a short distance; this causes the door to rise relative to the door frame so that suitable locking elements provided on the one hand on the door and on the other hand on the door frame mutually engage to mechanically lock the door to the frame; to open the door it is again lowered to mutually disengage the locking elements.
If the compressed air fails or if by accident pressure is removed from the actuator, the weight of the door and column causes them to fall spontaneously so that the door is no longer in a locked state, which can be dangerous for passengers especially during movement of the vehicle. To obviate this drawback, devices are known which safeguard the mechanically locked state of the door. These devices consist of very complicated mechanisms which position a mechanical stop element under an abutment rigid with the column to prevent this latter from falling after it has been raised, and also remove it therefrom. Besides being complicated and hence relatively costly such devices require very accurate installation within the door operating unit to prevent the door being able to descend slightly from its locked position because of too large clearances, and hence allow the locking elements to mutually disengage before the column is halted by the stop element.
An object of the present invention is to provide a door operating device able to close the door, then raise it slightly into its locked position and to safely maintain it in this position even if pressurized fluid is absent from the actuator, which is constructionally simple, is reliable and does not require particular attention and accuracy in its installation with respect to the locking elements.
This and further objects are attained by the device of the invention as characterised in the claims.
The invention is described in detail hereinafter with reference to the accompanying figures which illustrate two embodiments thereof.
Figure 1 is an overall view of a first embodiment of the device applied to a door.
Figures 2A and 2B together represent an axial section through a detail of the device of Figure 1 to an enlarged scale.
Figure 3 is a schematic view of a second embodiment of the detail of Figure 2A.
Figure 1 shows part of a vehicle, typically for transporting persons, which comprises a door 1 for closing an aperture in the door frame 9. The door 1 is supported by a support structure 10 rotatable about a vertical axis of rotation A and operated by a fluid actuator 2 in such a manner as to move the door 1 relative to the door aperture. The door 1 is locked to the frame 9 by being moved upwards when in its closed position. This is achieved by suitable locking elements 8 of known type (shown summarily in the figures), for example by plates fixed both to the door 1 and to the frame 9 and engaging mutually in the manner of latches to prevent the door moving away from the door aperture in a horizontal direction.
According to the invention, the support structure 10 comprises a first support element 11 arranged to rotate about said axis of rotation A coaxial thereto, and fixed to the door frame 9 such as not to be able to undergo vertical movement. The structure 10 also comprises a second support element 12 which is supported by said first element 11 in such a manner as to be able to rotate about the axis A and to move vertically relative to the element 11; said second element 12 is fixed to the door 1 to move vertically therewith. In addition there are provided a first piston 31 slidable under sealed conditions within a relative first chamber 33 filled with operating liquid and rigid with the first element 11, and a second piston 32 rigid with said second element 12 and slidable under sealed conditions within a relative second chamber 34 filled with operating liquid and rigid with the first element 11. The first chamber 33 communicates with the second chamber 34 via a passage duct 35 such that compression of the first chamber 33 produces expansion of the second chamber 34, expansion of the second chamber 34 resulting in the raising of the second piston 32 relative to the chamber 34. Transmission means 20 operated by the actuator 2 are provided to rotate the first element 11 when this is free to rotate, and to make the first piston 31 undergo a compression stroke within the first chamber 33 when the first element 11 is prevented from rotating and the actuator 2 is operated in the sense of closing the door.
Valve means 40 are also provided to automatically close the passage 35 for the operating liquid from the second chamber 34 to the first chamber 33, said passage 35 being able to be opened by external control.
Specifically, the first element 11 is in the form of a column and comprises a cylindrical axial inner cavity closed upperly by a wall 36, below which the first piston 31 slides under sealed conditions; the cavity region between the piston 31 and the upper wall 36 defines said first chamber 33.
According to a first embodiment, the support structure 10 comprises a vertical upright 13 rigidly fixed to transverse arms 14 fixed to the column 11. The upright 13 comprises an inner cylindrical axial cavity with a closed lower base 15, and in which the second piston 32 slides under sealed conditions; the cavity region between the lower base 15 and the piston 32 defines said second chamber 34. The second support element 12 is rigidly joined to the piston 32.
In the embodiment shown in Figure 1, the piston 32 is of "plunger" type, its seal against the chamber 34 being formed by gaskets 341 rigid with the wall of the chamber 31 and positioned within the upper region thereof, said gaskets 341 sealing against the smooth cylindrical surface of the piston 32.
The passage duct 35 is provided within one of the arms 14, this being internally hollow, and communicates with the chambers 33 and 34 via lateral holes 351 and 352 respectively, provided at the points where the arm 14 is fixed to the column 11 and to the upright 13 respectively. The element 12 is integral with the piston 32 and is upperly pivoted by a pin 121 to a bracket 122 fixed to the door 1. Within the lower part of the upright 13 there is a member 16 slidable vertically relative to the upright 13 and having its lower end constrained to the door 1 in a vertical direction by the fact of said lower end being pivoted by a pin 161 to a bracket fixed to the door 1. Thrust means, for example a precompressed spring 163, act on the member 16 to constantly urge the member 16 downwards relative to the upright 13.
The transmission means 20 are of the screw transmission type and are positioned in the lower region of the internal cavity of the column 11. Said means 20 comprise a transmission element 21 coaxial to the column 11 and having a cylindrical outer surface which exactly mates with the cylindrical inner surface 111 of the column 11; the element 21 is torsionally constrained to the column 11 by the engagement between grooves and axial projections 211 provided between the lower region of the outer surface of the element 21 and the inner surface of the lower region 112 of the column 11. The element 21 is free to slide axially relative to the column 11. The first piston 31 is fixed rigidly to the upper part of the element 21. The element 21 is engaged by the actuator 2 in such a manner as to rotate about the axis A of the column 11 when this is free to rotate, and instead to slide axially upwards relative to the column 11 when this is prevented from rotating and the actuator 2 is operated in the sense of closing the door.
In the embodiment shown in Figure 2, to achieve the described movement of the element 21, the means 20 comprise a cylindrical shaft 22 slidable within an axial cylindrical cavity 23 in the interior of the element 21 and rigidly fixed to the mobile member (rod 3) of the actuator 2 which is of linear type (ie in which the stroke of the mobile member is rectilinear), and further being constrained to the door frame 9 in such a manner as to be able to move only in an axial direction thereto. This constraint is achieved by the engagement between axial projections and grooves 221 provided between the lower region of the surface of the shaft 22 and the inner surface of a bore 251 provided in a fixing body 25 which rigidly fixes the actuator 2 to the frame 9. The body 251 extends upwards about the bore 251 to define a sleeve 252 housed between the inner surface of the lower region of the element 21 and the outer surface of the shaft 22. The bore 251 within the sleeve 252 is traversed by the lower part of the shaft 22. On the body 25, at the base of the sleeve 252 there is an upwardly facing surface 253 on which the lower end of the column 11 rests via an axial thrust bearing 26. Consequently the body 25 supports not only the actuator 2 but also the column 11 and all the members contained therein. The mutually facing cylindrical surfaces of the shaft 22 and axial cavity 23 are provided with identical mutually facing helical grooves 24 which together define one or more helical channels containing balls 241 which constrain the shaft 22 and the surface of the axial cavity 23 and hence the transmission element 21 to each other. The helix formed by these grooves has a relatively steep inclination such that during the closure of the door the movement (which is only axial) of the shaft 22 preferably causes the element 21 to rotate and, only when the structure 10 is no longer able to rotate, causes the element 21 to move upwards relative to the shaft 22 and column 11. In the figures the reference numeral 242 indicates a retainer positioned between the upper region of the cylindrical surface of the shaft 22 and the surface of the axial cavity 23 to hold the balls together. The grooves 24 provided in the shaft 22 extend along the entire length thereof to enable the screw engagement to allow a relatively long axial movement of the shaft 22 relative to the element 21. The column 11 is axially constrained (ie cannot be moved axially) to the frame 9 by being engaged at its upper end, by way of a bearing 113, with a bracket 114 fixed to the frame 9.
The valve means 40 shown in the figures comprise an electrically operated unidirectional valve 41 of known type. Briefly, said valve 41 comprises a valving member 42 arranged to close a channel 353, forming part of the duct 351, only when fluid flows from the chamber 34 to the chamber 33. To open this passage an electromagnet 43 is operated (in know manner) to raise a needle element 44 to enable the action of the fluid to raise the valving member 43. The valve 41 can be by-passed by a second valve 45, operated manually by a lever 451 and a pull rod 452. The valve 45 is normally closed and allows fluid to pass only when the pull rod 452 is pulled.
It will be assumed that initially the door 1 is open and that the actuator 2 is not operated (ie with its movable member 3 retracted downwards). In this situation the piston 32 is lowered within the chamber 33 and the piston 31 is in its lower end position (as shown in Figure 2).
To close the door, pressure is applied to the actuator 2 so that it extends its rod 3 and urges the shaft 22 upwards. This thrust is opposed by the downwardly directed thrust provided by the weight of the door 1 and of other members rigid therewith and by the force of the spring 163 transmitted to the piston 31 via the liquid filling the chambers 33, 34 and the duct 35. In relation to the relatively steep inclination of the grooves 24, said opposing thrusts cause the movement of the shaft 22 to initially produce only rotation of the element 21 about the axis A without any axial movement. This produces integral rotation of the column 11 and hence of the structure 10, with consequent movement of the door 1 until it rests against the door aperture. The movement of the door 1 and structure 10 is guided by one or more levers 4 hinged to the door and to the frame such that the door undergoes roto-translational movement.
When the door 1 rests against the frame 9, because of the fact that rotation of the element 21 is prevented the further upward movement of the rod of the actuator 2 causes the piston 31 to rise by virtue of the helical engagement between 22 and 21 (the column 11 being axially fixed). This produces compression of the chamber 33, the liquid contained in it passing through the duct 35 and into the chamber 34 as the valve 41 allows this passage. The expansion of the chamber 34 results in axial raising of the piston 32 and hence of the support element 12 and with this the door 1 (against the action of the spring 163). This raising results in mutual engagement of the locking elements 8 so mechanically locking the door 1 to the frame 9, this locking being protected even if the operating pressure fails in the actuator 2, in that the operating liquid cannot leave the chamber 34 as the valve 41 prevents the liquid returning to the chamber 33, the piston 32 hence being maintained constantly raised.
To open the door, the rod of the actuator 2 is moved downwards with simultaneous opening of the valve 41 by controlled electromagnetic action. The operating liquid can hence pass from the chamber 34 to the chamber 33 and this, by virtue of the weight of the door 1, the action of the spring 163 and the suction action of the piston 31, causes firstly the downward movement of the piston 32 and hence disengagement of the elements 8, and then rotation of the column 11 of the structure 10 in the opening direction.
The second valve is used to release the door 1 from its closed position, for example if because of a fault or another reason it is not possible to open the solenoid valve 41. In this case the pull rod 452 is used to manually operate the lever 451 which opens the valve 45, so enabling the liquid to return to the chamber 33.
The locking system according to the present invention is simple and reliable. The installation of the door 1 and structure 10 do not require particular precision in relation to the position of the locking elements 8 because the door 1 moves upwards until the locking elements 8 have mutually engaged and is then maintained automatically by the action of the valve 41 in the position reached, whatever this position is. This also means that there is substantially no slack between the locking members 8.
Figure 3 shows a second embodiment, which differs from the preceding in that the second chamber 34 is formed within a second cylindrical axial cavity provided in the column 11 above the wall 36, and the second support element 12 is defined by a cylindrical jacket, coaxial and external to the column 11, which supports the door 1 both for rotation and for vertical movement. In this case the arms 14 are fixed to the jacket 12 and the door 1 is fixed to the arms 14 so as to move vertically with them. The jacket 12 is constrained by axial grooves and projections 191 to the column 11 so that it rotates rigidly with it but is able to undergo vertical movement relative to it. The second piston 32 is rigidly fixed to the cylindrical jacket 12 and the passage duct 35 is provided within the wall 36, to which the valve means 40 are applied.
The operation of the device is substantially as heretofore described, with the difference that rotation of the column 11 produces rotation of the jacket 12 and hence of the structure 10, whereas upward movement of the piston 31 produces consequent movement of the piston 32 and hence the raising of the jacket 12 and thereby of the door 1.

Claims

A device for operating the door of vehicle door units, comprising a door (1) support structure (10) rotatable about a vertical axis of rotation and operated by a fluid actuator (2), said door (1) being locked to the door frame (9) by being moved upwards when in its closed position, characterised by comprising:
- a first element (11) of the support structure (10), able to rotate about said axis of rotation (A) coaxial thereto and fixed to the door frame (9) in a vertical direction;

- a second element (12) of the support structure (10), supported by said first element (11) in a manner rotatable about the axis of rotation (A) and movable vertically relative to said element (11), said second element (12) being fixed to the door (1) to move vertically therewith;

- a first piston (31) slidable under sealed conditions within a relative first chamber (33) filled with operating liquid and rigid with said first support element (11);

- a second piston (32) slidable under sealed conditions within a relative second chamber (34) filled with operating liquid and rigid with said first support element (11), said first chamber (33) communicating with said second chamber (34) via a passage duct (35) such that compression of the first chamber (33) produces expansion of the second chamber (34), the expansion of the second chamber (34) causing the second piston (32) to rise relative to the chamber (34);

- valve means (40) to automatically close the passage (35) for the operating liquid from the second chamber (34) to the first chamber (33), said passage being able to be opened by external control.
A device as claimed in claim 1, characterised in that said first element (11) is of column form and comprises a cylindrical axial inner cavity closed upperly by a wall (36) under which said first piston (31) slides as an exact fit, that cavity region between said first piston (31) and said upper wall (36) defining said first chamber (33).
A device as claimed in claim 2, characterised in that said transmission means are of screw transmission type and comprise a transmission element (21) coaxial to said column (11) and positioned within the lower region of the inner cavity thereof, it being torsionally constrained to the column (11) and freely slidable in an axial direction therein;
- said transmission element (21) being operated by the actuator (2) in such a manner as to rotate about the axis (A) of the column (11) when this is free to rotate, but to slide axially upwards relative to the column (11) when this is prevented from rotating and the actuator is operated in the sense of closing the door;

- said first piston (31) being rigid with the upper part of said transmission element (21).
A device as claimed in claim 3 in which said actuator is of linear type, characterised in that said transmission means (20) comprise:
- a shaft (22) slidable within a second cylindrical axial cavity (23) provided in the interior of the transmission element (21), said shaft (22) being rigidly fixed to the mobile member (3) of the actuator and being constrained to the door frame (9) in such a manner as to be able to move only in an axial direction thereto;

- the mating surfaces of the shaft (22) and said axial cavity (23) being provided with mutually facing helical grooves which define one or more helical channels containing balls (241) arranged to constrain the shaft (22) and transmission element (21) to each other, the helix of said grooves (24) having a relatively steep inclination such that during the closure of the door the movement of the shaft (22) preferably causes the transmission element (21) to rotate and, only when the column (11) is prevented from rotating, causes the transmission element (21) to move upwards.
A device as claimed in claim 2, characterised in that said support structure (10) comprises a vertical upright (13) rigidly fixed to transverse arms (14) rigidly fixed to the column (11), said upright (13) having an axial inner cavity with a closed lower end (15), within which cavity said second piston (32) slides under sealed conditions, that cavity region between the lower end (15) and the second piston (32) defining said second chamber (34), said second support element (12) being rigidly joined to the second piston (32).
A device as claimed in claim 5, characterised by comprising a member (16) slidable in a vertical direction within the lower part of said vertical upright (13) and having its lower end constrained to the door (1) in a vertical direction, and thrust means (163) arranged to constantly urge said slidable member (16) downwards.
A device as claimed in claim 2, characterised in that said second support element (12) is defined by a cylindrical jacket which is coaxial and external to said column (11) and rotationally constrained thereto but able to undergo vertical movement, and which supports the door (1) both for rotation and for vertical movement;
- said second chamber (34) being defined within a second cylindrical axial cavity provided in the interior of said column (11) above said wall (36);

- said second piston (32) being rigidly fixed to said cylindrical jacket (12);

- said passage duct (35) being provided within said wall (36).