ES2680627T3 - Control circuit for a pneumatically operated vehicle door - Google Patents

Abstract

Control circuit for a pneumatically controlled vehicle door comprising a double-acting pneumatic cylinder (9) that can be operated to open and close said door and having a first chamber (10) and a second chamber (11), a block of main pneumatic control (5) having a first working hole (7) and a second working hole (8), a first line (12) connected to the first chamber (10) of the cylinder (9) and constituting a line release in a given direction of movement of the cylinder (9) corresponding to a first direction of movement of the door, a second line (13) connected to the second chamber (11) of the cylinder (9) and constituting a load line in said direction of movement, and a safety device (42) configured to connect the first line (12) to the first working hole (7) in normal operation and to connect the first line (12) to the second line (13) in response to a control signal that id identifies that the door is blocked by an obstacle in said first direction of movement of the door, characterized in that said safety device includes a pressure switch (50) that detects the pressure level of said first line (12) and a valve three-way (43) that is spring biased to connect said first line (12) to said first hole (7) and solenoid controllable through said control signal to connect said first line (12) to said second line ( 13) to balance the air pressure in the two chambers of said cylinder, said control signal being enabled or disabled by said pressure switch (50) in response to the pressure level in said first line.

Description

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DESCRIPTION

Control circuit for a pneumatically operated vehicle door

The present invention relates to a control circuit for a pneumatically operated vehicle door.

The invention may preferably, but not exclusively, be used for the control of passenger car doors, such as buses, trains or the like. This application will be referred to below only by reference, without any limiting effect.

Passenger vehicle doors are often controlled by pneumatic actuators. If a person or an object is in the path of the door, a significant impact may occur. For safety reasons, it is therefore desirable that in case of impact, the door stops in order to avoid injury and / or damage to passengers. Furthermore, it is desirable that the door, after such possible impact, can be controlled manually without too much effort to open or close, depending on the direction of movement in which the impact occurred, in order to prevent people and / or objects can be released.

WO 2012/007739-A discloses a control circuit for a pneumatically operated door according to the preamble of claim 1. This circuit uses a compensating valve and an adjustable pilot operated valve.

An object of the present application is to solve the above problems simply and profitably.

A further object of the present invention is to devise a solution that can be applied not only to newly produced vehicles, but also used to equip existing vehicles.

These objects are achieved by a control circuit according to claim 1 and a method according to claim 4.

Two embodiments of the present inventions will be described below with reference to the attached drawings, in which:

Figure 1 is a pneumatic scheme of a circuit according to a first embodiment of the present invention;

Figure 2 and Figure 3 represent the circuit of Figure 1 in one of two different operating conditions; Y

Figure 4 is a pneumatic scheme of a second embodiment of the present invention.

Referring to Figure 1, a control circuit for a vehicle door, for example, a single front door bus, is indicated as a whole by number 1.

Circuit 1 essentially comprises:

- a source of compressed air 2,

- a supply line 3 connected to the source of compressed air 2 by a pressure regulator 4,

- a main control block 5 having an inlet hole 6 and a first and second working holes 7, 8;

- a double acting cylinder 9 having a first chamber 10 and a second chamber 11 connected, respectively, to the first working hole 7 by a first line 12 and to the second working hole 8 by a second line 13.

More specifically, the main control block 5 comprises a 5-way 2-way main solenoid valve 14 comprising:

- an inlet port 20 connected to the inlet port 6 through a soft start device 21, known per se and not described in more detail;

- a first and second ventilation holes 22, 23; Y

- a first and second line holes 24, 25 connected, respectively, to said first and second lines 12, 13.

Solenoid valve 14 is controlled by solenoid and pilot, with pilot lines 26, 27 connected to a pilot orifice of

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input 28 of the main control block 5. Subject to an electrical control signal on the respective control side of the solenoid valve 14, the pilot lines 26, 27 are connected to an AND valve 29, the output of which is connected to a hole exit pilot 30.

The main control block 5 also includes a pair of unidirectional flow control valves 31, 32 in the first and second lines 7, 8 to regulate the speed of the cylinder 9.

The circuit 1 also comprises an opening valve 33 of the external emergency door and an opening valve 34 of the internal emergency door (hereinafter "emergency valves 33, 34" for reasons of brevity).

Emergency valves 33, 34 are 3-way and 2-way valves that are connected in series. The emergency valve 33 has an inlet port 35 connected to the feed line 3 and an outlet port 36 connected to an inlet port 37 of the valve 34, whose outlet port 38 is connected to the inlet port 6 of the block main control 5. The emergency valves 33, 34 are normally set in the open position (so that the hole 6 is connected to the supply line 3) by the respective pilot lines 39a, 39b, connected to the pilot hole of Exit 30 of the main control block 5 (as described below), but can be manually set to the ventilation position in case of emergency in order to allow the door to be opened (respectively, from outside the vehicle and from the inside the vehicle).

The main box 5 finally comprises a check valve 40 that connects the first line orifice 7 to the inlet port 6 for a quick release in case of emergency.

In accordance with the present invention, circuit 1 includes a safety device 42 that includes a three-way valve and two positions 43 on the first line 12, which has a first hole 44 connected to the first working hole 7 of the control block main 5 through a first portion 45 of the first line 12, a second hole 46 connected to the first line 12 and a third hole 47 connected to the second line 13.

The valve 43 is deflected by spring in a position that connects the first orifice 44 with the second orifice 46, the third orifice 47 being closed.

The valve 43 can be operated by solenoid by an electrical signal line 48 to change to a second position that connects the second orifice 46 with the third orifice 47, the first orifice 44 being closed.

More particularly, a solenoid 49 of the valve 43 is connected in series to a pressure-operated switch 50 and a microswitch 51 along the signal line 48, which is powered by the vehicle's battery voltage. The pressure operated switch 50 is pneumatically connected to the connection step 45 in order to act on the signal line 48 in response to the pressure in the connection step 45. The microswitch 51 can be operated (in a conventional manner not shown in the drawings) by the cylinder 9 in order to disconnect line 48 just before the door leaf (not shown) reaches a fully open position, and therefore deactivates the safety device 42.

The operation of circuit 1 is as follows.

Under normal conditions, that is, in the absence of manual operation of the emergency valves 33, 34 and of the obstacles in the path of the door, the main control block 5 operates in a conventional manner.

When the main solenoid valve 14 is excited by a closing signal (Figure 1), the first line 12 is pressurized through the valve 43 and the cylinder 9 is moved to or maintained in the closed position of the door (Figure 1 ).

When the main solenoid valve 14 is excited by an opening signal (Figure 2), the second line 13 is pressurized and the cylinder moves to or remains in the door opening position.

If the door, during the opening movement, hits a person or obstacle and is blocked (Figure 3), a decrease in acute pressure occurs in the first line 12, which is detected by the pressure switch 50 (the connection step being 45 in direct communication with the first line 12 through the safety valve 43), which enables a control signal to the valve 43. As a consequence, the valve 43 changes to the second position, in which the second hole 46 it is connected to the third hole 47 and, therefore, the second hole 46 of the first line 12 is connected to the second line 13 and pressurized, thus connecting the two chambers 10 and 11 of the cylinder 9, which are both by both under pressure. Since the pressure forces acting on the cylinder are in equilibrium, the opening movement of the door stops, and the door can be moved manually without significant efforts.

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Normal operation can be restored by a close command, which brings the circuit back to the condition of Figure 1.

In the closed position, the door can be opened manually in case of emergency through the external emergency valve 33 or the internal emergency valve 34. The inlet port 6 of the main control block 5 is purged and the check valve 40 opens, releasing the pressure of the first line 12. The door can therefore be opened manually.

The emergency valves 33, 34 are reset by opening the control signal acting on the main valve 14 (in accordance with ECE Regulation R107).

It should be noted that emergency manual operation valves 33, 34 is possible only when the vehicle is stationary. When the vehicle speed exceeds a low threshold value, predetermined, for example, 5 km / h, a permanent closing signal acts on the main valve 14, and therefore the pilot signal on the pilot lines 38, 39 is also active and the pneumatic pilot force prevails over manual operation.

Figure 4 depicts a circuit 100 in accordance with a second embodiment of the present invention, which is configured for the parallel control of two cylinders 9 that control the respective wings of a double-door bus.

In this case, the entire circuit portion downstream of the holes 24, 25 is simply bent in parallel; each cylinder 9 has its own lines 12, 13, corresponding unidirectional flow control valves 31.32 and check valve 40, and its own safety device 42, which is configured to release the respective door in case it is blocked by a person or an obstacle during its opening.

The advantages provided by the present invention are evident from an analysis of the characteristics of circuits 1, 100.

In particular, the safety device 42 allows the vehicle door to be stopped and controlled manually without significant efforts after an impact on a person or obstacle in its trajectory in a simple and cost-effective manner.

In addition, the security device is a completely autonomous system that can be used in all types of door systems without any impact on the control logic or software of the door. It can also be used to equip existing vehicles.

Obviously, modifications and variants of the circuit are possible, without departing from the scope of the appended claims.

In particular, the safety device 42 can be configured to act on the closing stroke of the door, rather than the opening stroke, depending on the kinematics of the door.

Claims (2)

5 10 fifteen twenty 25 30 1. Control circuit for a pneumatically controlled vehicle door comprising a double acting pneumatic cylinder (9) that can be operated to open and close said door and having a first chamber (10) and a second chamber (11), a main pneumatic control block (5) having a first working hole (7) and a second working hole (8), a first line (12) connected to the first chamber (10) of the cylinder (9) and constituting a release line in a given direction of movement of the cylinder (9) corresponding to a first direction of movement of the door, a second line (13) connected to the second chamber (11) of the cylinder (9) and constituting a line of loading in said direction of movement, and a safety device (42) configured to connect the first line (12) to the first working hole (7) in normal operation and to connect the first line (12) to the second line ( 13) in response to a control signal identifying that the door is blocked by an obstacle in said first direction of movement of the door, characterized in that said safety device includes a pressure switch (50) that detects the pressure level of said first line (12 ) and a three-way valve (43) that is deflected by spring to connect said first line (12) to said first hole (7) and controllable by solenoid through said control signal to connect said first line (12) to said second line (13) for balancing the air pressure in the two chambers of said cylinder, said control signal being enabled or disabled by said pressure switch (50) in response to the pressure level in said first line. 2. Control procedure of a double acting pneumatic cylinder (9) that drives a vehicle door, the cylinder (9) comprising a first chamber (10) connected to a first line constituting a release line in a direction of movement given from the cylinder (9) corresponding to a first direction of movement of the door, and a second chamber (11) connected to a second line (13) that constitutes a load line in said direction of movement, the procedure including the stage of balancing the air pressure in the two chambers (10, 11) of the cylinder (9) in response to a control signal that identifies that the door is blocked by an obstacle in said first direction of movement of the door, characterized in that said stage is carried out through a pressure switch (50) that detects the pressure level of said first line (12) and a three-way valve (43) that can be controlled by solenoid through of said control signal for connecting said first line (12) to said second line (13) in order to balance the air pressure in the two chambers of said cylinder, said control signal being enabled or disabled by said pressure switch ( 50) in response to the pressure level in said first line.