FR3064321A1 - CONTROL DEVICE HAVING A CYLINDER - Google Patents

Abstract

The invention relates to a control device (1) comprising a cylinder (10) and an electronic device (30), wherein: - the cylinder (10) comprises a body (12) extending along a longitudinal axis (X) and comprising an internal bore (14), and a piston (16) housed in the internal bore (14) and slidable in said internal bore along the longitudinal axis (X), - the electronic device (30) ) comprises an elastic means (32) and a force sensor (34) capable of measuring and delivering a physical quantity related to the position of the piston (16) in the body (12) of the cylinder, the elastic means (32) being arranged between the piston (16) and the force sensor (34) so that the displacement of the piston (16) in the body (12) causes a deformation of the elastic means (32), and the force sensor (34) being suitable measuring a force exerted by the elastic means (32) during its deformation.

Description

® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number: 3,064,321 (to be used only for reproduction orders)

©) National registration number: 17 52417

COURBEVOIE

©) Int Cl ⁸ : F16 D 125/04 (2017.01), F16D 25/063

A1 PATENT APPLICATION

©) Date of filing: 23.03.17. © Applicant (s): VALEO EMBRAYAGES Company by (30) Priority: simplified actions - FR. ©) Inventor (s): MARCHISIO JEAN-MICHEL. @) Date of public availability of the request: 28.09.18 Bulletin 18/39. (56) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ©) Holder (s): VALEO EMBRAYAGES Company by related: simplified actions. ©) Extension request (s): ©) Agent (s): VALEO EMBRAYAGES Company by simplified actions.

CONTROL DEVICE COMPRISING A CYLINDER.

FR 3 064 321 - A1 (£ /) The invention relates to a control device (1) comprising a cylinder (10) and an electronic device (30), in which:

the cylinder (10) comprises a body (12) extending along a longitudinal axis (X) and comprising an internal bore (14), and a piston (16) housed in the internal bore (14) and able to slide in said internal bore along the longitudinal axis (X),

- the electronic device (30) comprises an elastic means (32) and a force sensor (34) capable of measuring and delivering a physical quantity linked to the position of the piston (16) in the body (12) of the cylinder, the means elastic (32) being arranged between the piston (16) and the force sensor (34) so that the displacement of the piston (16) in the body (12) causes a deformation of the elastic means (32), and the sensor force (34) being able to measure a force exerted by the elastic means (32) during its deformation.

Control device comprising a cylinder

The invention relates to the field of actuators, in particular actuators for motor vehicles and relates more particularly to a control device comprising a measuring device assembled to the body of the cylinder.

Such control devices for motor vehicles are used in particular in clutch or braking devices for motor vehicles.

In a known manner, such control devices comprise a cylinder comprising a body in which a piston slides and a housing fixed to the body of the cylinder and in which is housed an electronic device capable of measuring and delivering a physical quantity linked to the operation of the cylinder, in particular related to the relative position of the piston in the cylinder. Generally, a magnet is arranged on the piston and the electronic device includes a sensor configured to detect the magnetic field generated by the magnet.

However, in order to compensate for the increasing electromagnetic disturbances in motor vehicles, the magnet arranged on the piston must require increasing dimensions in order to obtain a precise measurement of the position of the piston in the body of the cylinder by the sensor, generating costs. significant production.

In addition, taking into account the increasing reliability requirements in the automobile, the assembly must ensure a very precise fixing of the housings on the body of the actuators in order to ensure a good precision of the sensors housed in these housings.

The invention aims to remedy these drawbacks by proposing a control device indifferent to electromagnetic disturbances.

To this end, the subject of the present invention is a control device comprising a cylinder and an electronic device, in which:

- the cylinder comprises a body extending along a longitudinal axis and comprising an internal bore, and a piston housed in the internal bore and capable of sliding in said internal bore along the longitudinal axis,

the electronic device comprises an elastic means and a force sensor capable of measuring and delivering a physical quantity linked to the position of the piston in the cylinder body, the elastic means being arranged between the piston and the force sensor so that the displacement of the piston in the body results in a deformation of the elastic means, and the force sensor being able to measure a force exerted by the elastic means during its deformation.

Advantageously, such a control device guarantees a reliable and precise measurement of the position of the piston in the body of the cylinder. In addition, the measuring device does not include a magnet and is therefore not subject to any electromagnetic disturbances from its environment.

The control device according to the invention can also include one or more of the characteristics below, considered individually or according to all technically possible combinations:

- The elastic means has a first end fixed to a transverse face of the piston and a second end bearing against the force sensor;

- the force sensor is attached to a transverse wall of the body;

- The elastic means is a spring;

- The spring is a helical spring or an elastomer compression spring or a stack of Belleville washers;

- The elastic means is an element made of elastic deformable material;

- the elastic deformable material is an elastomer;

- the elastic means and the force sensor are housed in a chamber of the cylinder body, the chamber is delimited by the transverse wall of the cylinder body to which the force sensor is attached, by the internal bore and by the face of the piston to which the first end of the spring is fixed;

- The chamber is a variable volume chamber of the cylinder body;

- The piston comprises a control rod extending along the longitudinal axis from the transverse face of the piston and passing through an orifice formed in the assembly formed by the force sensor and the transverse wall of the cylinder body;

- the elastic means surrounds the control rod;

- The force sensor is a piezoelectric sensor;

- the electronic device comprises a processing unit capable of delivering information related to the position of the piston in the cylinder body from the electrical signal generated by the force sensor, the processing unit being fixed on the cylinder body;

- the cylinder is a motor vehicle clutch cylinder or a brake cylinder;

- the cylinder is a hydraulic cylinder or a pneumatic cylinder;

- the cylinder is a transmitter or receiver type cylinder;

- the cylinder body and / or the piston are mainly made of plastic.

Another object of the invention relates to a method of measuring the position of a piston in a body of a cylinder of a control device according to any one of the preceding claims, comprising a step of measuring a quantity physics related to the position of the piston in the cylinder body by the force sensor of the control device.

Other characteristics and advantages of the invention will appear on reading the detailed description of several embodiments given solely by way of nonlimiting and illustrative examples, with reference to the appended figure which illustrates a view in longitudinal section of an embodiment of a control device according to the invention.

In the figure, the different elements are not necessarily shown to scale in order to present a view making it easier to understand the invention.

In the description and the claims, the terms external and internal, or “external” and “internal”, as well as the axial and radial orientations, will be used to designate, according to the definitions given in the description, elements of the control cylinder. hydraulic. By convention, the radial orientation is directed orthogonally to the axis X of sliding of the piston of the cylinder determining the axial orientation and, from the inside towards the outside while moving away from said axis. The terms external and internal or "exterior" and "interior" are used to define the relative position of one element with respect to another, with reference to the X axis, an element close to the axis is thus qualified internal as opposed to an external element located radially on the periphery. Furthermore, the terms rear AR and front AV are used to define the relative position of one element with respect to another in the axial direction.

FIG. 1 illustrates a control device 1 according to a preferred embodiment of the invention. The control device 1 comprises a cylinder 10 having a generally tubular body 12 extending axially along a longitudinal axis, denoted X.

The body 12 has an internal bore 14 housing a piston 16. The piston 16 is capable of sliding in the internal bore 14 along the longitudinal axis X. The piston 16 comprises a control rod 17 extending along the longitudinal axis X from a transverse face of the piston.

The body 12 comprises at the front a first chamber 18 of variable volume, called the front chamber 18, which is delimited axially, from front to rear, by a front transverse wall 20 of the body 12, by the internal bore 14 and by a front face 22 of the piston 16. In addition, the front chamber 18 is configured to receive a fluid 24. For example, the fluid comprises a gas or a liquid or a mixture of gases and liquids. Preferably, the fluid 24 mainly comprises oil.

In addition, the body 12 comprises at the rear a second chamber 25 with variable volume, called the rear chamber 25, which is delimited axially, from front to rear, by a rear face 26 of the piston 16 opposite the front face 22 of the piston, by the internal bore 14 and by a rear transverse wall 28 of the body 12 opposite the front transverse wall 20 of the body. The variations in volume at a given instant in the front 18 and rear 25 chambers are complementary so that the total volume of the volumes in the front 18 and rear 25 chambers is invariant over time.

Furthermore, the body 12 of the cylinder can be made in one piece or at least two parts, namely a front part and a rear part which are joined to each other.

The body 12 can be made of plastic, for example reinforced polyamide 6-6, of metal by molding or forging and then machining, or can be made partly of metal and partly of plastic.

The piston 16 is made of metal or plastic.

This type of cylinder is in particular intended for use in hydraulic clutch control systems for a motor vehicle which comprise a cylinder of the transmitter type, called the transmitter or control cylinder, which is connected by a hydraulic circuit to a cylinder of the receiver type. , says receiver. Thus, the receiver also comprises a body having an internal bore in which a piston slides, the latter being capable of acting on the stop of a clutch, for example by means of a control rod acting on a fork d 'clutch.

In operation, the transmitter is intended to expel a fluid, such as oil, which is contained in its front chamber, in particular a hydraulic chamber for a hydraulic cylinder, towards the receiver. When the driver disengages, the control rod 17 of the cylinder 10 is moved so that the piston 16 of the cylinder 10 drives the hydraulic fluid towards the receiver so as to actuate the clutch.

The control device 1 also comprises an electronic device 30 comprising an elastic means 32 and a force sensor 34 capable of measuring and delivering a physical quantity linked to the position of the piston 16 in the body 12 of the cylinder O.

The elastic means 32 and the force sensor 34 are housed in the rear chamber 25 of the body 12 of the cylinder 10.

The elastic means 32 is arranged between the piston 16 and the force sensor 34 so that the displacement of the piston 16 in the body 12 results in a deformation of the elastic means 32.

The force sensor 34 is able to measure the force exerted by the elastic means 32 during its deformation. Preferably, the force sensor 34 is a piezoelectric sensor.

According to the embodiment illustrated in FIG. 1, the force sensor 34 is attached to the rear transverse wall 28 of the body 12.

Advantageously, the elastic means 32 is a spring 36 having a first end 40 fixed to the rear transverse face 26 of the piston 16 and a second end 44 bearing against the force sensor 34. The displacement of the piston 16 in the body 12 causes, in particular a deformation of the spring 36 along the longitudinal axis X.

Preferably, the spring 36 is a helical spring. Alternatively, the spring 36 is an elastomeric compression spring or a stack of Belleville washers.

In another embodiment not shown, the elastic means can be an element of elastic deformable material having a first end fixed to the rear transverse face of the piston and a second end in abutment against the force sensor. The elastic deformable material can be an elastomer, such as rubber.

The control rod 17 extends along the longitudinal axis X from the rear transverse face 26 of the piston 14. It is shaped to pass through an orifice 46 formed in the assembly formed by the force sensor 34 and the transverse wall rear 28 of the body 12 of the cylinder 10. Advantageously, the spring 36 surrounds the control rod 17.

In operation, still in the case of a cylinder of the emitter type of a hydraulic clutch control device, when the driver disengages, the control rod 17 of the cylinder 10 is moved so that the piston 16 of the cylinder 10 drives the hydraulic fluid towards the receiver so as to activate the clutch. Thus, when the conductor disengages, the control rod 17 is moved so that the piston 16 slides in the internal bore 14 from back to front thereby reducing the volume of the front chamber 18 containing the hydraulic fluid 24 and consequently increasing the volume of the rear chamber 25 in which the spring 36 decompresses. The force applied by the spring 36 on the force sensor 34 decreases.

Conversely, when the front chamber 18 fills with hydraulic fluid 24, its volume increases while the volume of the rear chamber 25 decreases further by moving the piston back and forth. The spring 36 is then more and more compressed as the volume of the front chamber 18 increases, thus generating an increasing force on the force sensor 34.

In addition, the electronic device 30 comprises a processing unit 50 capable of delivering information linked to the position of the piston 16 in the cylinder body from the electrical signal generated by the force sensor 34. The processing unit 50 is fixed to the body 12 of the cylinder 10.

Furthermore, the electronic device 30 may include a connector (not shown) for connecting the electronic device, and in particular the processing unit 50, to other electrical and electronic components, such as a control unit of a motor vehicle, so as to allow the exchange of data between the cylinder and its environment.

A control device according to the invention makes it possible to implement a method for measuring the position of a piston in a cylinder body according to the invention by measuring a physical quantity linked to the position of the piston in the cylinder body by the force sensor of the control device.

In other words, the force sensor of the control device measures the force exerted by the elastic means and transcribes it into a position of the piston in the body of the cylinder.

Advantageously, such a control device according to the invention thus makes it possible to guarantee a reliable and precise measurement of the position of the piston in the body of the cylinder without the use of a magnet and therefore without subjecting the measurement device to any electromagnetic disturbances. of its environment.

According to the invention, the cylinder can be a transmitter or receiver type cylinder. In addition, the cylinder of the control device can in particular be a motor vehicle clutch cylinder or a motor vehicle brake cylinder. Furthermore, the cylinder can be a hydraulic cylinder or a pneumatic cylinder.

Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

The use of the verb "behave", "understand" or "include" and its conjugate forms does not exclude the presence of other elements or steps than those set out in a claim. The use of the indefinite article "a >> or" a >> for an element or a stage does not exclude, unless otherwise stated, the presence of a plurality of such elements or stages.

In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims (14)

1. Control device (1) comprising a cylinder (10) and an electronic device (30), in which: the cylinder (10) comprises a body (12) extending along a longitudinal axis (X) and comprising an internal bore (14), and a piston (16) housed in the internal bore (14) and able to slide in said internal bore along the longitudinal axis (X), - the electronic device (30) comprises an elastic means (32) and a force sensor (34) capable of measuring and delivering a physical quantity linked to the position of the piston (16) in the body (12) of the cylinder, the means elastic (32) being arranged between the piston (16) and the force sensor (34) so that the displacement of the piston (16) in the body (12) causes a deformation of the elastic means (32), and the sensor force (34) being able to measure a force exerted by the elastic means (32) during its deformation. 2. Control device according to claim 1, in which the elastic means has a first end (40) fixed to a transverse face (26) of the piston (16) and a second end (44) bearing against the force sensor ( 34), the force sensor (34) being attached to a transverse wall (28) of the body (12). 3. Control device according to claim 2, in which the elastic means and the force sensor (34) are housed in a chamber (25) of the body (12) of the cylinder (10), the chamber (25) being delimited by the transverse wall (28) of the body (12) of the cylinder to which the force sensor (34) is attached, by the internal bore (14) and by the transverse face (26) of the piston (16) to which is fixed the first end (40) of the spring (36). 4. Control device according to claim 2 or 3, wherein the piston (16) comprises a control rod (17) extending along the longitudinal axis (X) from the transverse face (26) of the piston ( 16) and passing through an orifice (46) formed in the assembly formed by the force sensor (34) and the transverse wall (28) of the body (12) of the cylinder (10). 5. Control device according to claim 4, wherein the elastic means surrounds the control rod (17). 6. Control device according to any one of the preceding claims, in which the elastic means is a spring (36) and / or an element made of elastic deformable material. 7. Control device according to claim 6, in which the spring (36) is a helical spring or an elastomer compression spring or a stack of Belleville washers. 8. Control device according to any one of claims 1 to 7, in which the force sensor (34) is a piezoelectric sensor. 9. Control device according to any one of claims 1 to 8, in which the electronic device (30) comprises a processing unit (50) capable of delivering information linked to the position of the piston (16) in the body ( 12) of the cylinder (10) from the electrical signal generated by the force sensor (34), the processing unit (50) being fixed on the body of the cylinder. 10. Control device according to any one of the preceding claims, in which the cylinder is a motor vehicle clutch cylinder or a braking cylinder. 11. Control device according to any one of the preceding claims, in which the cylinder is a hydraulic cylinder or a pneumatic cylinder. 12. Control device according to any one of the preceding claims, in which the cylinder is a cylinder of the transmitter or receiver type. 13. Control device according to any one of the preceding claims, in which the body (12) of the cylinder and / or the piston (16) are mainly made of plastic. 14. A method of measuring the position of a piston in a body of a cylinder of a control device (1) according to any one of the preceding claims, comprising a step of measuring a physical quantity related to the position of the piston in the cylinder body by the force sensor of the control device. 1/1