FR2595420A3 - PNEUMATIC ACTUATING DEVICE FOR CONTROLLING THE DISPLACEMENT OF A CONTROL MEMBER IN AN AXIAL DIRECTION GIVEN - Google Patents

Abstract

THE INVENTION RELATES TO A PNEUMATIC ACTUATION DEVICE FOR COMMANDING THE DISPLACEMENT OF A CONTROL ELEMENT IN A GIVEN AXIAL DIRECTION. THE DEVICE INCLUDES A BODY 3 IN WHICH TWO BEDROOMS 1, 2 ARE SHAPED, A WALL OF THE FIRST BEDROOM 1 CONSTITUTING BY A FIRST DEFORMABLE DIAPHRAGM 5 PROVIDED WITH A BODY 8 AND MOVABLE BETWEEN TWO LIMIT POSITIONS, ONE OF WHICH IS DEFINED BY CONTACT OF ORGAN 8 WITH A FIRST STOP 12, A WALL OF THE SECOND CHAMBER 2 BEING DEFINED BY A SECOND DEFORMABLE DIAPHRAGM 6 JOINT TO A CONTROL ELEMENT 20 AND ALSO MOVABLE BETWEEN TWO LIMIT POSITIONS, ONE OF WHICH IS DEFINED BY CONTACT WITH A SURFACE 22 OF THE CONTROL ELEMENT WITH A SECOND STOP 23, THE JOINT 8 JOINT OF THE FIRST DIAPHRAGM 5 IS PROVIDED WITH A FIRST SHOULDER 10 COOPERATING WITH A SECOND SHOULDER 25 PROVIDED ON THE CONTROL ELEMENT 20 IN ORDER TO CONTROL THE MOVEMENTS OF THE DIAPHRAGMS 5, 6 BETWEEN THEIR RELATIVE LIMIT POSITIONS. APPLICATION TO MOTOR VEHICLE ENGINES.

Description

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  The present invention relates to a pneumatic actuating device for controlling the displacement of a control element in a given axial direction, and allowing two different displacements independently of one another. Pneumatic actuators of the type mentioned above are usually controlled by a vacuum generated by a suitable source, in particular the vacuum inside the manifold of an internal combustion engine, and they are usually used to control different

  components and devices on motor vehicles.

  Known actuating devices of the type mentioned above usually comprise a body in which is formed a first chamber communicating with said source and a wall of which is defined by a first deformable diaphragm moving substantially in the axial direction of the element. control in the actuating device. Said first deformable diaphragm moves in said direction from a first limit position, where it is in contact with a

  stopping surface of the body, to a second position

  limit, o an integral part of the diaphragm

  comes into contact with a first stop, whose posi-

  tion is adjustable in said direction. The actuation device also comprises a second chamber communicating with said source and a wall of which is defined by a second deformable diaphragm, integral with said control element and also arranged to move, in the aforementioned direction, from a first limit position it is in contact with a stop surface provided on said body, in a second limit position, where a surface of said control element is in contact with said integral element

said first diaphragm.

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  A first displacement of the control element is produced by connecting the two aforementioned chambers of the actuating device with said vacuum source. In a similar manner, said first diaphragm moves to said second limit position, and said second diaphragm is stopped against the integral member of the first diaphragm. To control a displacement of the control element other than that described above, only the second chamber is connected to the vacuum source in such a way that the first diaphragm moves to the first limit position, and the second diaphragm into the second limit position, against the integral element

of the first diaphragm.

  However actuators of the

  type mentioned above do not produce two

  different parts of the control element which are independently adjustable. While a displacement can be suitably adjusted by varying the position of said stop, the other depends on the geometry of the device itself which can not be changed. The present invention aims to create

  a pneumatic actuating device of the type

  above, but which is designed to remedy the aforementioned drawback, that is to say an actuating device for two different races and

  independently adjustable from the control element.

  To solve this problem, in accordance with the present invention, a pneumatic actuator is created for controlling the displacement of a control element in a given axial direction between an initial position and two different end positions, said device actuation being controlled by a vacuum produced by a source

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  appropriate, especially the empty space inside

  the collector of an internal combustion engine; character-

  characterized in that it comprises a body in which is formed a first chamber communicating with said source and a wall of which is defined by a first deformable diaphragm moving substantially in said direction from a first limit position, where it is in contact with a stop surface provided on said body, in a second limit position where an integral member of said first diaphragm comes into contact with a first stop whose position can be set in said direction, a second chamber communicating with said source and one of which wall is defined by a second deformable diaphragm secured to said control member and also moving substantially in said direction from a first limit position to a second limit position where a surface of said control member is in contact with a second stop, the relative position of said surface of said control element being regulated ble in said direction relative to said second stop, and said integral member of the first diaphragm being provided with a first shoulder cooperating with a second shoulder provided on said control member, for moving said second diaphragm of the first relative limit position in the second relative limit position, after a displacement of said first diaphragm from the first relative limit position to the

second relative limit position.

  Other features and advantages of the invention will be highlighted later in the

  description, given by way of non-limiting example,

  with reference to the attached single drawing which shows an axial sectional view of an actuating device

  pneumatic device according to the present invention.

  The actuating device according to the present invention essentially comprises first and second chambers, 1 and 2, formed inside.

  a body 3 of the actuating device itself.

  Through a tube 4, each of said chambers 1 and 2 communicates with a source of vacuum, for example the exhaust manifold of an internal combustion engine, so as to produce a given vacuum

inside each room.

  The actuating device also comprises two substantially coaxial diaphragms 5 and 6 and defining a respective wall of the chambers 1 and 2, as clearly shown in the accompanying drawing. The edges of the diaphragm 5 are held between parts 3a and 3b of said body 3, while those of the diaphragm 6 are held between parts 3b and 3c. The diaphragm comprises two plates 7 and an integral member 8

  provided with a shank 9 and an extreme head 10. The di-

  5 is adapted to move substantially from a first limit position, in which one of the plates 7 is in contact with the surface 11 of the body 3, to a second limit position, in which the central portion of the element 8 is stopped against the end of a stop 12 having a threaded rod which is screwed into a corresponding threaded hole of the

  body and which can be regulated from outside the

  actuating device by means of a head 13. Between said head 13 and the body 3, there is provided a means advantageously constituted by a coil spring 17

  to prevent the head 13 from being accidentally unscrewed

  is lying. It is also provided a sealing ring 18

  to ensure effective sealing of the chamber 1.

  The diaphragm 6 comprises a pair of plates 19 and an integral control element 20, whose displacement

  axial is controlled by the actuating device.

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  This control element preferably has a tubular shape and has a threaded end portion on which is screwed a threaded annular nut 21, whose axial position can be adjusted with respect to said control element and whose surface 22 is arranged to enter in contact with an abutment surface 23 of the body 3. As clearly shown in the accompanying drawing, said abutment member has an inner hole 24 in which is introduced the head 10 of the member 8; and said control member has an annular protrusion 25 projecting towards the hole 24 and acting as a shoulder for the head 10. The hole 24 is advantageously closed by a buffer 26; and a connecting member, for example a hook 27, is arranged to connect the element

  of the actuating device with the control mechanism

der by this one.

  The diaphragm 6 is arranged so as to

  move from a first limit position, representing

  1 in the drawing and in which the shoulder of the annular protuberance 25 contacts the head 10 of the member 8, to a second limit position o the active surface 22 of the annular nut 21

  contacts the abutment surface 23 of the body 3.

  Between the diaphragm 6 and a support surface 28 of the body 3, a helical spring 29 is interposed so as to fix the diaphragm 6 normally in said

first limit position.

  The actuating device described above operates as follows. A first stroke of the control member 20, designated Cl in the drawing, can be established by adjusting the end of the stop 12 relative to the upper surface of the member 8, by a simple

  rotation of the stop by means of the head 13.

  A second stroke of the control element, designated C2 in the drawing, can be established completely independently of the first stroke by adjusting the annular nut 21 to place the surface 22 at a given distance from the surface of the

stop 23 of the body 3.

  To traverse the first aforementioned stroke Cl the actuating device is moved by a simple connection of the first chamber 1 with the vacuum source, causing the diaphragm 5 to move from said first limit position shown in the drawing to said second position limit, which is reached when the surface 30 of the member 8 is stopped against the end of the abutment 12. A displacement of the diaphragm 5, via the member 8, produces a displacement of the control element 20 in the right direction. When the vacuum prevailing in the chamber 1 is decreased, the actuating device is returned to the position indicated in the drawing under the action of the coil spring 29, which controls the downward movement of the control element 20 and also of the diaphragm 5 via the connection between

  the head 10 and the annular protuberance 25.

  For the control member 20 to travel C2, the chamber 2 is connected to the vacuum source to cause the diaphragm 6 to move upwardly in opposition to the force exerted by the spring 29. During this movement, the control element 20 has no influence on the member 8, which remains in its initial position. The limit position of the control element 20 is reached, in this second case, when the surface 22 of the annular nut 21 comes to apply.

  against the abutment surface 23 of the body 3.

  It follows, therefore, that the

  actuator according to the present invention

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  produces two different and completely independent races (C1, C2) of the control element 20,

  said races can also be adjusted

independently.

  The actuator according to the present invention also has a very simplified and compact structure and is therefore

  very reliable and inexpensive.

  Of course, the present invention is not limited to the embodiments described and shown; it is capable of many variants accessible to those skilled in the art, depending on the intended applications and without departing from the spirit of the invention.

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Claims (6)

  A pneumatic actuating device for controlling the displacement of a control element in a given axial direction between an initial position and two different end positions; said actuating device being controlled by a vacuum produced by a suitable source, in particular the vacuum prevailing inside the collector of an internal combustion engine, characterized in that it comprises a body (3) in which are formed a first chamber (1) communicating with said source and a wall of which is defined by a first deformable diaphragm (5) moving substantially in said direction from a first limit position, where it is in contact with a stop surface ( 11) provided on said body (3), in a second limit position where a member (8) integral with said first diaphragm (5) comes into contact with a first stop (12) whose position can be adjusted in said direction, and second chamber (2) communicating with said source and a wall of which is defined by a second deformable diaphragm (6) integral with said control element (20) and also moving substantially in said area e direction from a first limit position to a second limit position o a surface of said control member (20) is in contact with a second stop (23), the relative position of said surface of said control member (20) being adjustable in said direction relative to said second stop (23), and said member (8) integral with said first diaphragm (5) being provided with a first shoulder (10) cooperating with a second shoulder (25) provided on said control element (20), for moving said second diaphragm (6) from the first relative limit position to the second relative limit position, after a displacement of said first diaphragm (5) from the first relative limit position to the second relative limit position.   2. Actuating device according to the   cation 1, characterized in that said control element (20) comprises a threaded annular nut (21) screwed onto the element (20) itself, said annular nut (21) having a surface (22) arranged to abutting a surface (23) of said body (3) for the purpose of stopping a displacement of said control member (20) after a displacement of said first diaphragm (5) from said first limit position to   in said second limit position.   3. Actuating device according to one of   claims 1 or 2, characterized by the fact that   member (8) integral with said first diaphragm (5) comprises a rod (9) provided with a head (10) inserted into an axial hole (24) formed in said control element (20) and cooperating with an annular projection (25). ) of the element (20) proper.   4. Actuating device according to any one   Claims 1 to 3, characterized by the fact that   comprises a spring (29) interposed between said second diaphragm (6) and a shoulder (28) of said body (3) and arranged normally to retain said diaphragm (6) in said first position.   5. Actuating device according to any one   Claims 1 to 4, characterized in that   said first stop consists of a threaded rod (9)   screwed into a hole (24) of said body (3).   6. Actuating device according to any one   Claims 1 to 5, characterized in that   said body (3) comprises at least three parts (3a, 3b, 3c), the first diaphragm (5) being maintained between a first 2595420   (3a) and a second (3b) of said portions, and said second diaphragm (6) being maintained between the second (3b) and the third part (3c).