System for measuring an angular position relative to a reference position
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- CROUZET SA
- Filing Date
- 2026-01-26
- Publication Date
- 2026-08-06
Smart Images
Figure EP2026051890_06082026_PF_FP_ABST
Abstract
Description
[0001] System for measuring an angular position relative to a reference position
[0002] [1] The invention relates to a system for measuring an angular position relative to a reference position and to a method for manufacturing this measuring system.
[0003] [2] Such measuring systems are used, in particular, to measure the angular position of a utensil relative to a fixed body. Typically, such a measuring system comprises:
[0004] - a fixed body,
[0005] - a rotating assembly mounted on an axis of revolution fixed to the stationary body, and
[0006] - an angular sensor that generates an electrical signal representative of the angular position of the rotating assembly relative to the reference position.
[0007] [3] The angular sensor comprises a rotating portion, fixed on the rotating assembly, and a stationary portion fixed on the body.
[0008] [4] The stationary portion of the sensor must be fixed simply and precisely inside the body of the measuring system. Various methods of fixing the stationary portion of the sensor to the fixed body have been proposed for this purpose. For example, application FR3107779A1 describes inserting the printed circuit board containing the stationary portion of the sensor into a housing and then securing the printed circuit board in this housing with a pin. Application FR3107779A1 further describes that once the printed circuit board is fixed inside the housing with the pin, its position is permanently locked by pouring a curable resin into the housing.
[0009] [5] Application EP2264408A1 describes a mounting of the printed circuit board containing the stationary portion of the sensor onto the body of a measuring system. For this purpose, the body has elastically deformable clips and protrusions formed within it. The protrusions in the body cooperate with corresponding recesses in the printed circuit board to correctly and precisely position the printed circuit board within the body.
[0010] [6] However, the various known methods of attaching the stationary portion of the sensor to the body are not both simple and precise. It is therefore desirable to have a measurement system in which the attachment of the stationary portion of the sensor to the body is both simple and precise.
[0011] [7] In such a measuring system, it is sometimes necessary to adjust the reference position relative to the stationary body. This requires the ability to adjust the angular position of the stationary portion of the angular sensor relative to the stationary body. US patent application 11788828B1 discloses an adjustment mechanism comprising a cam. The stationary portion of the angular sensor is fixed to this cam. In the case of US patent application 11788828B1, the rotating assembly rotates within a cylindrical housing machined into the stationary body, and the cam is mounted on a flat external face of the stationary body into which this housing opens. Since the cam is located on an external face of the stationary body, it is possible to adjust its angular position, and thus the angular position of the stationary portion, even though the angular sensor and the rotating assembly are already mounted on the stationary body.More specifically, the cam of the US11788828B1 application has oblong holes that extend in an arc around the axis of revolution of the rotating assembly and screws that allow the cam to be fixed in the desired angular position. The adjustment mechanism of the US11788828B1 application is advantageous because it is simple to implement and allows the reference position to be adjusted even when the rotating assembly is already mounted on the fixed body. However, it is bulky, particularly because the cam is fixed to the outside of the fixed body. Furthermore, precise adjustment of the reference position is difficult with this mechanism. Indeed, when the screws are tightened, their heads rub against the cam, creating a force that unpredictably displaces the cam from its initial position, that is, from its position before tightening.
[0012] [8] The prior art is also known from DE102020216342B4, DE102019200029A1, EP3250889B1 and DE102017127743A1.
[0013] [9] It is therefore also desirable to propose a measurement system equipped with a reference position adjustment mechanism that is less bulky.
[0014]
[0010] The invention aims to satisfy at least one of these wishes.
[0015]
[0011] The invention is set forth in the attached set of claims.
[0012] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the drawings in which:
[0016] - Figure 1 is a schematic, perspective illustration of a system for measuring an angular position relative to a reference position.
[0017] - Figure 2 is an exploded view of the system in Figure 1,
[0018] - Figure 3 is an exploded view of a measuring module of the system in Figure 1, - Figure 4 is a vertical cross-sectional view of details of the measuring module in Figure 3.
[0019] - Figure 5 is an exploded and perspective view of two parts of the module in Figure 3,
[0020] - Figure 6 is a schematic, partial, vertical cross-sectional view of the module in Figure 3,
[0021] - Figure 7 is a schematic, partial, vertical cross-sectional view of details of the module in Figure 3,
[0022] - Figure 8 is a vertical cross-sectional perspective view of details of an adjustment mechanism for the module of Figure 3,
[0023] - Figure 9 is a vertical cross-sectional perspective view of the system shown in Figure 1.
[0024] - Figure 10 is a partial, perspective view of a return mechanism for the module shown in Figure 3.
[0025] - Figure 11 is a flowchart of a manufacturing process for the system shown in Figure 1,
[0026] - Figure 12 is a partial, vertical cross-sectional view of a variant of the module mounting shown in Figure 3.
[0027] - Figure 13 is a partial, vertical cross-sectional view of a variant of the adjustment mechanism shown in Figure 8.
[0028] - Figure 14 is a schematic illustration, in vertical section, of another variant of the adjustment mechanism of Figure 8, and
[0029] - Figure 15 is a schematic illustration, in longitudinal section, of another variant of a fixing of the module of Figure 3.
[0030]
[0013] In this description, the terminology, conventions, and definitions of the terms used in this text are introduced in Chapter I. Detailed examples of embodiments are then described in Chapter II with reference to the figures. In Chapter III, variants of these embodiments are presented. Finally, the advantages of the different embodiments are specified in Chapter IV.
[0031]
[0014] Chapter I: Definitions, terminology and conventions:
[0032]
[0015] In the figures, the same references are used to designate the same elements.
[0033]
[0016] In the remainder of this description, the well-known characteristics and functions of a person skilled in the art are not described in detail.
[0034]
[0017] The figures are oriented with respect to an orthogonal XYZ coordinate system, where the X and Y directions are horizontal and the Z direction is vertical. Terms such as "above," "below," "top," "bottom," "superior," and "lower" are defined with respect to the Z direction. The terms "front" and "back" are defined with respect to the X direction. The terms "left" and "right" are defined with respect to the Y direction.
[0035]
[0018] The expression "an element made of a material A" or the expression "an element made of material A" means that material A represents 90% or 95% of the mass of that element.
[0036]
[0019] The symbol “*” denotes scalar multiplication.
[0037]
[0020] In this text, a "fixed" part means a part that does not move when the rotating assembly described in the following chapter rotates around its axis of revolution.
[0038]
[0021] The term "axial position" refers to the position of a part along the axis of revolution.
[0039]
[0022] A hardenable material is a material that is initially in a paste or liquid state and subsequently hardens to a solid state. In the paste or liquid state, this material can be injected or poured into a cavity to fill the cavity and its irregularities. In the solid state, this material forms a block of hard material that can no longer be removed from the cavity. The block of hard material cannot be removed from the cavity because of the adhesion of the hardenable material to the walls of the cavity and / or due to its conformity with the cavity's irregularities. Such a hardenable material is typically an epoxy resin, an adhesive, or a cement.
[0023] Chapter: Examples of Embodiments
[0040]
[0041]
[0024] Figures 1 and 2 represent a system 2 for measuring an angular position relative to a reference position. In this embodiment, system 2 is a human-machine interface designed to be manipulated with the thumb to make adjustments or selections. In this case, system 2 is known as a thumbwheel. More specifically, system 2 is intended here for use in piloting an aircraft.
[0042]
[0025] The system 2 comprises a utensil 4 mounted for rotation about a single horizontal axis 6 of revolution. In the figures, the axis 6 is parallel to the X direction. The utensil 4 is directly operable by hand by a user. To this end, in this embodiment, the utensil 4 is a semi-circular piece whose axis of revolution coincides with the axis 6. The utensil 4 extends around the axis 6 from a lower edge 4A located in front of the axis 6 to a lower edge 4B located behind the axis 6. The angle between a first plane containing the axis 6 and passing through the edge 4A and a second plane containing the axis 6 and passing through the edge 4B is greater than 30° or 45° and, generally, less than 270° or 200°. Here, this angle is equal to 96°.
[0043]
[0026] Here, to prevent the user's thumb from slipping when rotating utensil 4, the upper face of utensil 4 is notched.
[0044]
[0027] The utensil 4 can be rotated about the axis 6 between a neutral position shown in Figure 1 and positions inclined to the right and positions inclined to the left. Here, in the neutral position, the geometric center of the utensil 4 is located in a vertical plane containing the axis 6. The neutral position is the position that the utensil 4 occupies in the absence of external forces. Here, the angular position α of the utensil 4 is located relative to a reference position which, for example, corresponds to the neutral position. The angular position α is therefore equal to the angle between:
[0045] - a first plane containing axis 6 and passing through the geometric center of the utensil 4 when it is in its neutral position, and
[0046] - a second plane containing the axis 6 and passing through the geometric center of the utensil 4 when it is in an inclined position.
[0047] With this definition of angular position a, the neutral position of utensil 4 corresponds to a value of zero. By convention, when utensil 4 is tilted to the right, the angular position a is positive, and when utensil 4 is tilted to the left, the angular position a is negative. Typically, the angular position a varies between -90° and +90°, and often between -20° and +20°.
[0048]
[0028] In this embodiment, the utensil 4 is housed in a fixed cover 10. For example, this cover 10 has stops which limit the angular movement of the utensil 4 around the axis 6.
[0049]
[0029] The utensil 4 is fixed, without any degree of freedom, onto a synchronizing arm 12 (Fig. 2). For example, the utensil 4 is fixed onto the arm 12 by means of a screw 14.
[0050]
[0030] In this embodiment, the system 2 comprises three measuring modules 20, 22, and 24 (Fig. 2), each capable of independently measuring the angular position a of the tool 4. Modules 20, 22, and 24 thus provide three redundant measurements of the same angular position a. Consequently, in the event of a total failure of one or two measuring modules, the system 2 can still provide a measurement of the angular position a. Furthermore, the use of three independent measuring modules also allows for the detection of an erroneous measurement from one of the measuring modules. Thus, the redundancy of the three measuring modules meets operational safety criteria.
[0051]
[0031] Here, modules 20, 22, and 24 are joined one after the other in the X direction. Modules 20, 22, and 24 are fixed to each other without any degree of freedom by fixing screws. In Figure 2, only two fixing screws 26 and 28 are shown.
[0052]
[0032] In this embodiment, the three modules 20, 22, 24 are identical to each other. Thus, subsequently, only module 22 is described in detail with reference to Figures 3 to 10.
[0053]
[0033] The module 22 comprises a fixed body 30 (Fig. 3), a bearing 36 (Fig. 3), a rotating assembly 38 (Fig. 3) and an angular sensor 40 (Fig. 4).
[0054]
[0034] The body 30 constitutes the fixed frame of the module 22. The body 30 is intended to be fixed, without any degree of freedom, on the fixed bodies of the other modules 20 and 24 using the screws 26, 28. For this purpose, the body 30 has two through holes 50, 52 (Fig.
[0055] 3) diametrically opposed with respect to axis 6 and intended to be each traversed by the shank of screws 26, 28. Here, the body 30 also has fixing fins 54 (Fig. 3) allowing, for example, to fix, without any degree of freedom, this body 30 on a dashboard or other fixed support.
[0056]
[0035] The body 30 also includes a housing 56 (Fig. 3), essentially cylindrical, centered on the axis 6. In this embodiment, the housing 56 is through and extends, along the axis 6, from a front opening 58 (Fig. 3) to a rear opening 60 (Fig. 3).
[0057]
[0036] In this embodiment, the body 30 also includes tapped holes 62 for fixing, without any degree of freedom, a plate 64 (Fig. 9) in a position where it completely closes the rear opening 60.
[0058]
[0037] The bearing 36 forms a pivot joint that allows the rotating assembly 38 to rotate about the axis 6. Here, the bearing 36 has an inner ring 70 (Fig. 4) and an outer ring 72 (Fig. 4) that can rotate freely relative to each other. These rings 70, 72 are centered on the axis 6. For example, the bearing 36 is here a ball bearing.
[0059]
[0038] The rotating assembly 38 is fixed without any degree of freedom on the inner ring 70. For this purpose, the assembly 38 includes a tubular protrusion 74 (Fig. 4) which is received inside the ring 70 and a bearing surface 76 (Fig. 4) which comes directly into contact only with the periphery of the inner ring 70. Here, the bearing surface 76 is annular and extends in a vertical plane perpendicular to the axis 6.
[0060]
[0039] Assembly 38 is driven in rotation about axis 6 by tool 4. For this purpose, assembly 38 is fixed, without any degree of freedom, to the synchronizing arm 12. Since the rotating assemblies of each of the modules 20, 22, and 24 are mechanically connected, without any degree of freedom, to the same synchronizing arm 12, the angular displacements of these assemblies about axis 6 are all identical. For example, assembly 38 has two tapped holes 78, 80 (Fig. 3) to receive screws for fixing the arm 12 to this assembly 38.
[0061]
[0040] The angular sensor 40 generates an electrical signal representative of the angular position a. For this purpose, the sensor 40 measures the angular position of the assembly 38. The sensor 40 comprises a rotating portion 90 (Fig. 3, 4) and a stationary portion 92 (Fig.
[0062] 4).
[0063]
[0041] The rotating portion 90 is fixed, without any degree of freedom, on the assembly 38. Here, the portion 90 is fixed inside the protrusion 74, for example, by pouring inside the protrusion 74 a hardenable material which, once hardened, forms a hard block 94 (Fig. 3, 4) which immobilizes the portion 90 inside the protrusion 74.
[0064]
[0042] In this embodiment, the portion 90 is centered on the axis 6 and includes lugs 96, 97 (Fig. 3) which, by cooperation of form with corresponding hollows arranged inside the protuberance 74, allow a single angular position of the portion 90 inside the protuberance 74.
[0065]
[0043] Here, portion 90 is passive, that is, it is not powered by an energy source. In this embodiment, portion 90 comprises a permanent magnet. For example, the direction of magnetization of this magnet lies in a vertical plane.
[0066]
[0044] Portion 92 includes a transducer sensitive to the angular position of the permanent magnet of portion 90 relative to this transducer. When using system 2, the angular position of portion 92 on axis 6 is fixed. Here, the transducer comprises a tunnel magnetoresistive element housed in a casing on the surface of which electrodes are provided for electrically connecting the magnetoresistive element to a printed circuit board 100 (Fig. 3, 4). The resistance value of the magnetoresistive element varies depending on the orientation of the permanent magnet relative to this magnetoresistive element. This transducer, and more specifically its casing, is centered on axis 6 and positioned opposite the permanent magnet. The air gap separating this transducer from the permanent magnet is generally less than 15 mm or 10 mm. Here, the thickness of this air gap is less than 5 mm or 2 mm.
[0067]
[0045] Here, the stationary portion 92 is soldered onto the printed circuit board 100 which includes other electronic components to process the measurement of the stationary portion 92. The printed circuit board 100 is connected, by wire links 102 (Fig. 9) which pass through the body 30, to an electronic control unit based on the measurement generated by this module 22.
[0068]
[0046] The reference position relative to which the angular position a of the utensil 4 is measured is fixed to the stationary portion 92. Therefore, in order for the angular positions a measured by each of the modules 20, 22, and 24 to be identical, the angular positions of the stationary portions of the sensors of these different modules must be adjusted so that, for the same inclination of the utensil 4, each of these sensors generates the same electrical signal. It should be noted that to obtain this result, in the case where the transducer includes a tunneling magnetoresistive device, it is not sufficient for the angular positions, on the axis 6, of the stationary portions 92 of the different modules to be identical.Indeed, due to variations in characteristics resulting from the manufacturing process of these transducers, it is common for the electrical signals generated by two transducers to differ even if their angular positions are identical, for the same angular position of the tool 4. This stems in particular from the fact that the reference position relative to the transducer housing can vary slightly from one transducer to another. Furthermore, the positioning of the rotating portion 90 within the assembly 38 is also subject to manufacturing and positioning tolerances. Thus, the angular positions of the rotating portions 90 in each of the modules 20, 22, and 24 are not always identical. This also means that even if the angular positions of the stationary portions 92 on the axis 6 are identical, the electrical signals generated by the sensors are not necessarily identical.
[0069]
[0047] To ensure that each of the modules 20, 22 and 24 generates the same electrical signal for the same inclination of the utensil 4, a reference position adjustment mechanism is provided in each of these modules. The adjustment mechanism of module 22 is designated by the numerical reference 110 (Fig. 7, 8).
[0070]
[0048] The adjustment mechanism 110 comprises:
[0071] - an initial fixation 112 (Fig. 7) capable of retaining the immobile portion 92 inside the housing 56, and
[0072] - a lever 114 (Fig. 8) for adjusting the angular position of the stationary portion 92 held inside the housing 56.
[0073]
[0049] The initial fixation 112 is capable, as long as no other fixation of the position of the stationary portion 92 has been implemented, of locking the axial position of the stationary portion 92 in the body 30. This initial fixation 112 also allows rotation of the stationary portion 92 about the axis 6 in response to a torque exceeding a predetermined threshold S c The predetermined threshold is typically greater than 0.01 Nm or 0.05 Nm and generally less than 20 Nm or 10 Nm. Here, the predetermined threshold is between 0.05 Nm and 5 Nm or between 0.05 Nm and 1 Nm.
[0074]
[0050] The fastener 112 includes a cam 120 (Fig. 3, 4) fully received inside the housing 56 of the body 30. The printed circuit board 100 is fixed, without any degree of freedom, to a rear face 122 of this cam 120. More precisely, the face 122 has a recess 124 (Fig. 5) whose dimensions are adjusted to receive the stationary portion 92. This recess 124 centers, by a process of shape cooperation, the stationary portion 92 on the axis 6. In addition, the cam 120 has a cylindrical wall 126 (Fig. 4, 5) centered on the axis 6 and which completely surrounds the face 122 to form, in combination with the face 122, a receptacle 128 inside which the printed circuit board 100 is received. The wall 126 has, on the side of the printed circuit board 100, a boss 130 (Fig. 5) which by cooperation of form with a corresponding hollow 132 (Fig. 5) arranged in the printed circuit 100 imposes the angular position of the circuit 100 inside the receptacle 128.
[0075]
[0051] Here, the printed circuit 100 is fixed, without any degree of freedom, inside the receptacle 128, for example, by pouring into the receptacle 128 a hardenable material which, once hardened, forms a hard block 134 (Fig. 3, 6) which immobilizes the printed circuit 100 inside this receptacle 128.
[0076]
[0052] Thus, to rotate the stationary portion 92 on the axis 6, it is necessary to rotate the cam 120 on this axis 6. For this, the cam 120 has a cylindrical wall 136 (Fig. 4) which, by cooperation of form with a corresponding cylindrical section 138 (Fig. 4) of the housing 56, guides the cam 120 in rotation around the axis 6.
[0077]
[0053] The cam 120 is introduced inside the housing 56 by passing through the front opening 58 and moving along an insertion direction F (Fig. 4, 7) parallel to the axis 6 and in the opposite direction to the X direction.
[0078]
[0054] To precisely lock the axial position and also lock the angular position of the cam 120 inside the housing 56 as long as no torque exceeds the threshold S c is not applied to this cam; the 112 fixing also includes:
[0079] - moving in direction F, a shoulder 150 (Fig. 4, 7) then an annular groove 152 (Fig. 4, 7) both formed in the outer periphery of the cam 120,
[0080] - moving in direction F, a shoulder 154 then a truncated conical face 156, both arranged inside the housing 56, and
[0081] - a 160 friction element.
[0082]
[0055] Shoulders 150, 154 are centered on axis 6. Shoulder 150 is turned towards the rear opening 60 of housing 56. Conversely, shoulder 154 is turned towards the front opening 58. Here, shoulders 150, 154 are annular and each contained in a vertical plane perpendicular to axis 6. In the mounted position of cam 120, shown in figures 4 and 7, shoulder 150 is directly supported on shoulder 154.
[0083]
[0056] The groove 152 is also centered on the axis 6.
[0084]
[0057] The member 160 constantly presses the shoulder 150 against the shoulder 154 and also constantly presses on the outer periphery of the cam 120. The member 160 is interposed between the outer periphery of the cam 120 and the housing 56. Here, the friction member 160 consists of a single O-ring received inside the groove 152. Thus, hereafter, the reference 160 is also used to designate this O-ring.
[0085]
[0058] In the mounted position, the frustoconical face 156 is located at the same level as the groove 152, i.e., they are opposite each other. The frustoconical face 156 flares outwards progressively and continuously as it moves in direction F. Thus, in the vertical sections of Figures 4 and 7 along axis 6, the face 156 forms an inclined plane that moves away from axis 6 as one moves in direction F.
[0086]
[0059] In the mounted position, the seal 160 rests against the frustoconical face 156. Thus, in the mounted position, the seal 160 continuously exerts force on the cam 120 in direction F, which keeps the shoulder 150 pressed against the shoulder 154. The axial position of the cam 120 is therefore locked and precise. Furthermore, the seal 160 locks, by friction, the angular position of the cam on the axis 6 as long as no torque exceeding the threshold S is applied. cis not applied to cam 120. Conversely, when a torque exceeding the threshold S c When applied to cam 120, cam 120 rotates on axis 6 without altering its axial position. Finally, in the mounted position, seal 160 also provides a seal between housing 56 and cam 120. Here, sealing refers, at a minimum, to sealing against the curable material that will be poured onto the rear face 122 of cam 120. However, in general, seal 160 provides a sealing rating greater than or equal to IP67.
[0087]
[0060] The lever 114 is accessible from outside the body 30 and, in the mounted position, is mechanically connected to the cam 120 to drive it in rotation about the axis 6 when moved by an operator. The lever 114 allows a torque greater than the threshold S to be applied. cto overcome the friction force of the seal 160 on the cam 120.
[0061] The lever 114 is housed inside a through hole 170 (Fig. 8) machined into the body 30. The hole 170 opens, on one side, into the housing 56 opposite the cam 120, and, on the opposite side, onto an outer face of the body 30. More precisely, in this embodiment, the mechanism 110 has a protrusion 172 formed on the cam 120 and offset with respect to the axis 6. Here, this protrusion 172 is a boss on the outer periphery of the cylindrical section 136. The housing 56 has a cavity 174 (Fig. 8) machined into this housing to receive this protrusion 172. This cavity is shaped to allow an angular deflection of the cam 120 of more than 5° or 10° about the axis 6, despite the presence of the protrusion. 172. Here, the cavity 174 is also shaped to limit the angular travel of the cam 120 to less than 45°.
[0088]
[0062] The through hole 170 opens into the cavity 174 opposite the asperity 172. In this embodiment, the through hole 170 has a thread, and the handle 114 has an adjustment screw 176 screwed into the through hole 170. This screw 176 has a head 178 and an end 180 bearing against the asperity 172. The head 178 can be rotated from outside the body 30 to screw the screw 176 into the through hole 170. For example, the head 178 has a notch for receiving the blade of a screwdriver. When the screw 176 is screwed into the through hole 170, the end 180 pushes the asperity 172 which causes the cam 120 to rotate in the direction R (Fig. 8) on the axis 6 against the friction force of the seal 160.
[0089]
[0063] However, the screw 176 does not allow the cam 120 to be rotated in the opposite direction to R. Thus, to adjust the angular position of the cam 120, the initial angular position of the cam 120 is such that the asperity 172 is in contact with the bottom of the cavity 174. Subsequently, the adjustment of the angular position can only be made by rotating the cam 120 in the R direction. No reversal is possible.
[0090]
[0064] In this embodiment, to allow the cam 120 to reverse in case of an error, the adjustment mechanism 110 further includes an additional asperity 182 (Fig. 8) formed on the cam 120 and housed in a cavity 184 (Fig. 8) in the housing 56. For example, the cavity 184 is the mirror image of the cavity 174 with respect to a vertical plane containing the axis 6. The mechanism 110 also includes a threaded through hole 186 which opens on one side into the outer face of the body 30 and, on the opposite side, into the cavity 184 opposite the asperity 182. By removing the screw 176 from the hole 170 and then screwing it into the hole 186, it is possible to rotate the cam 120 in the opposite direction to direction R and thus, for example, return the cam 120 to its angular position. initial.
[0091]
[0065] The wall 136 completely surrounds a front face 190 (Fig. 4) of the cam 120 to form, in combination with the face 190, a receptacle 192 (Fig. 4) in which the bearing 36 is received. More precisely, the receptacle 192 has an annular bearing surface 194 on which the outer ring 72 of the bearing 36 rests directly. For example, the ring 72 is fixed, without any degree of freedom, inside the receptacle 192 by bonding or any other means. Thus, in this embodiment, the assembly 38 is supported solely by the cam 120. Under these conditions, the thickness of the air gap between the permanent magnet and the transducer of the stationary portion 92 is independent of the axial position of the cam 120 inside the housing 56.
[0092]
[0066] Module 22 also includes a permanent fixing 200 (Fig. 9) for the angular position of the cam 120 on the axis 6. The fixing 200 is separate from and independent of the fixing 112. The fixing 200 is engaged after the angular position of the cam 120 has been adjusted using the mechanism 110. After its engagement, the fixing 200 prevents any movement of the cam 120 relative to the body 30. In particular, after the fixing 200 is engaged, the mechanism 110 no longer allows adjustment of the reference position.
[0093]
[0067] Here, the fastener 200 is formed by pouring a curable material between the plate 64 and the block 134. Once hardened, this material forms a block that immobilizes the cam 120 inside the housing 56. When the curable material is poured, it extends to the seal 160, which prevents it from passing through the front face 190 of the cam. Thus, in this case, the seal 160 also prevents the curable material from blocking the rotation of a part such as the ring 70 or the assembly 38. For example, to further secure the rotation of the cam 120, notches or ribs are provided on the inner face of the housing 56 so that they are filled with the curable material of the fastener 200.
[0094]
[0068] As illustrated in Figure 9, the system 2 may also include a haptic device 202 which modifies, in a non-linear manner, the force that a user must exert on the utensil 4 to move it when the utensil 4 is in a particular position such as its neutral position. For example, the haptic device 202 includes:
[0095] - a recess 204 (Fig. 3) fitted on the outer periphery of the assembly 38, - a sliding pin 206 (Fig. 9) mounted in a channel cut in the body 30, and - a spring 208 (Fig. 9) which constantly forces the pin 206 towards the outer periphery of the assembly 38.
[0096]
[0069] The recess 204 is shaped to receive the head of the pin 206 when this recess is located opposite the channel. The walls of this recess 204 are also shaped to repel, against the force exerted by the spring 208, the head of the pin 206 into the channel when the user applies a torque to the tool 4. Thus, from the neutral position, the user must exert a greater torque to free the rotation of the tool 4 on the axis 6.
[0097]
[0070] The system 2 also includes a mechanism 210 (Fig. 10) for returning the utensil 4 to its neutral position. Here, this mechanism 210 is only installed in the measuring module 24. The mechanism 210 includes, for example, a torsion spring 212 (Fig. 9, 10) whose coils are centered on the axis 6. This spring 212 has two fastening strands 214, 216. These strands 214, 216 are received, respectively, in the cavities 174 and 184 of the housing 56. Each strand 214, 216 also passes through a radial slot, respectively 218 and 220, provided in the periphery of the assembly 38. In the neutral position, shown in figure 10, the strands 214, 216 are simultaneously in contact with the body 30 and with the lower edges of the slots 218 and 220. When the utensil 4 is inclined, one of these strands 214, 216 remains in contact with the body 30 and the other of these strands 214, 216 is only in contact with the lower edge of the slot 218, 220 which it passes through.Thus, the spring 212 exerts on the assembly 38 a torque which returns the utensil 4 to its neutral position as soon as it is released by the user.
[0098]
[0071] Figure 11 represents a manufacturing process for system 2.
[0099]
[0072] This method includes a step 230 of assembling each of the measuring modules 20, 22, and 24. During step 230, the modules 20, 22, and 24 can be assembled in parallel independently of each other. This step 230 is described in the specific case of the measuring module 22, but everything described in this specific case applies to the case of modules 20 and 24.
[0100]
[0073] Phase 230 begins with a step 232 of supplying the various parts forming the measuring module 22 and described previously. During step 232, the supplied printed circuit board 100 is already fixed without any degrees of freedom, by the block 134, inside the receptacle 128 of the cam 120 as described previously. The seal 160 is also already received inside the groove 152. The rotating portion 90 of the sensor 40 is also already fixed, without any degrees of freedom, in the assembly 38. For this purpose, the rotating portion 90 is fixed inside the protrusion 74 of the assembly 38 using the block 94 of hardenable material.
[0101]
[0074] In step 234, the cam 120 is mounted inside the housing 56. To do this, the cam 120 is pushed into the housing 56 by moving it along the axis 6 in direction F until the shoulder 150 rests directly against the shoulder 154. The mounted position of the cam 120 is then reached. In this mounted position, the seal 160 rests against the frustoconical face 156, which keeps the shoulder 150 pressed against the shoulder 154. In addition, the angular position of the cam 120 is adjusted so that the asperity 172 rests against the end 180 of the screw 176. Typically, the cam 120 is mounted inside the housing 56 manually by an operator without the aid of any tools.
[0102]
[0075] During a step 236, the bearing 36 is mounted inside the receptacle 192. During this step 236, the outer ring 72 is fixed, without any degree of freedom, in support on the bearing surface 194.
[0103]
[0076] Then, in a step 238, the assembly 38 is mounted on the body 30. For this, the outer periphery of the protrusion 74 is fixed, without any degree of freedom, on the inner ring 70 of the bearing 36.
[0104]
[0077] The plate 64 is also fixed to the body 30 during the assembly phase 230.
[0105]
[0078] At the end of assembly phase 230, each of the modules 20, 22 and 24 is assembled.
[0106]
[0079] During a step 240, the modules 20, 22 and 24 are placed side by side and fixed to each other using the screws 26, 28.
[0107]
[0080] During a step 242, the synchronization arm 12 is mounted on the assemblies 38 of each of the modules 20, 22 and 24. The arm 12 is fixed without any degree of freedom to each of these assemblies 38. Thus, from this moment on, the rotations of these assemblies 38 are necessarily identical.
[0108]
[0081] During a step 244, the cover 10 is fixed onto the bodies 30 of the modules 20, 22 and 24 and then the tool 4 is fixed onto the arm 12.
[0109]
[0082] Then, in step 246, each of the assemblies 38 is positioned in the same predetermined angular position on the axis 6. For this purpose, for example, the utensil 4 is placed in its neutral position. When the system 2 includes the return mechanism 210, the utensil 4 is automatically held, in the absence of external forces, in this neutral position. Here, for each measuring module, this predetermined position is associated with a known desired value that the sensor 40 of that module must generate for this predetermined position. To improve the redundancy of the electrical signals generated by the modules 20, 22, and 24, the desired value for this predetermined position is the same for all modules. Moreover, typically, this desired value is identical for all measuring systems 2, which avoids specific calibration on the host product during initial assembly and allows for the interchangeability of the systems 2 during maintenance.
[0110]
[0083] During a step 248, for each module 20, 22 and 24, the angular position of the cam 120 of that module is adjusted using the adjustment mechanism 110 of that module until the sensor 40 generates the desired value.
[0111]
[0084] To this end, in step 248, for module 22, an operator moves the lever 114 of this module 22 and, simultaneously, the value of the electrical signal generated by the sensor 40 of module 22 is displayed. Here, the operator tightens the screw 176 using a screwdriver. When the displayed value is equal to the desired value, the operator stops moving the lever 114. The set angular position of the cam 120 is then locked by the seal 160, which rubs against the cam 120. The operator then repeats the same operations for modules 20 and 24.
[0112]
[0085] At the end of step 248, the sensors 40 of modules 20, 22 and 24 all generate the same electrical signal.
[0113]
[0086] Then, in step 250, for each of the modules 20, 22, and 24, the permanent fixing 200 is implemented. From that point on, any movement of the cams 120 relative to the bodies 30 is prohibited. In particular, the angular position of each cam 120 can no longer be adjusted using the mechanisms 110. Although still present in each of the modules 20, 22, and 24, the initial fixing 112 is no longer needed.
[0114]
[0087] The manufacture of system 2 is then completed and it can be installed in a dashboard and then used by a user such as a pilot.
[0115]
[0088] Figure 12 represents an initial fixation 260 that can be used instead of the initial fixation 112.
[0116]
[0089] The initial fixing 260 is identical to the initial fixing 112 except that: - the frustoconical face 156 is replaced by a frustoconical face 266 formed on the outer periphery of the cam 120 and located, in direction F, after the shoulder 150, and
[0117] - the groove 162 is replaced by an annular groove 262 fitted in the housing 56 of the body 30 and located, in the direction F, after the shoulder 154.
[0118]
[0090] The operation of the initial fixation 260 can be deduced from the explanations given in the case of the initial fixation 112.
[0119]
[0091] Figure 13 shows an adjustment mechanism 270 that can be used in place of the adjustment mechanism 110. The mechanism 270 is identical to the mechanism 110 except that the asperity 172 is replaced by an asperity 272. In this embodiment, the asperity 272 is not a boss but a notch made in the outer periphery of the cylindrical section 236 of the cam 120. The end 180 of the adjusting screw 176 bears directly against the bottom of this notch to rotate the cam 120 about the axis 6 when the screw 176 is tightened.
[0120]
[0092] Figure 14 shows an adjustment mechanism 280 that can be used in place of the adjustment mechanism 110. The mechanism 280 is identical to the mechanism 110 except that the handle 114 is replaced by a handle 282 and the hole 170 is replaced by a hole 284. In this embodiment, the handle 114 includes a lever 286 that is fixed, without any degrees of freedom, to the cam 120. For example, the lever 286 and the cam 120 form a single block of material. A distal end of the lever 286 is flush with an outer face of the body 30 or protrudes from this outer face so that it can be rotated about the axis 6, for example, by means of a screwdriver blade or directly by hand. Hole 284 is identical to hole 170 except that it is shaped to allow an angular travel of lever 286 on axis 6 greater than 10° or 15°.
[0121]
[0093] Figure 15 shows an initial fixing 290 that can be used in place of the initial fixing 112. The fixing 290 is identical to the fixing 290 except that: - the frustoconical face 156 is replaced by an annular ring 292 centered on the axis 6 and projecting inside the housing 56,
[0122] - the groove 152 and the joint 160 are replaced by elastically deformable hooks 294.
[0123]
[0094] The crown 292 forms a circular constriction inside the housing 56 of diameter D 292
[0095] The hooks 294 are uniformly distributed around the axis 6. The number of hooks 294 is three or four or more. Each hook 294 has a retention recess 296 suitable for receiving the crown 292. Each recess has a flat bottom. Here, in the rest position of the hooks 294, that is, in the absence of any external stress, the flat bottoms of the recesses 296 of the hooks 294 are all located on a circle, centered on the axis 6, whose diameter D 296 is slightly larger than diameter D 292 For example, the diameter D 296 is between l.005*D 292 and 1.15*D 292 OR between l,01*D 292 and 1.1*D 292 .
[0124]
[0096] The hooks 294 are shaped so that, when the cam 120 is pushed in the direction F into the housing 56, the hooks 294 bend, by elastic deformation, towards the axis 6 when they come into contact with the ring 292. Then, by continuing to push the cam 120 into the housing 56, when the shoulder 150 comes into contact with the shoulder 154, the hollows 296 are located opposite the ring 292 so that the hooks 294 return to their rest position by elastic deformation. The ring 292 is then received inside the recesses 296, which locks the axial position of the cam 120. Furthermore, in the embodiment shown in Figure 15, in the mounted position, each recess 296 has an inclined flat that rests on a beveled angle of the ring 292 so as to constantly apply force to the cam 120 in direction F. Since the diameter D 296 is greater than diameter D292 In the mounted position of the cam 120, the hooks 294 bear on the ring 292, which locks, by friction, the angular position of the cam 120. Thus, the hooks 294 form a friction element which functions similarly to the o-ring 160 except that the hooks 294 do not ensure the seal between the housing 56 and the cam 120.
[0125]
[0097] Chapter III: Variants:
[0126]
[0098] Variants of the initial fixation:
[0127]
[0099] Other embodiments of the shoulders 150, 154 are possible. For example, the shoulders may be frustoconical and each centered on the axis 6. The shoulders 150, 154 are also not necessarily annular. For example, they may also be present only in certain angular sectors and absent in other angular sectors.
[0100] The cross-section of the O-ring 160 is not necessarily circular. For example, alternatively, the cross-section of the O-ring is oval.
[0128]
[0101] Other shapes are possible for the cam 120. For example, the cam 120 may comprise more than two successive cylindrical sections of decreasing diameters going in the direction F. The cam may also comprise one or more frustoconical sections.
[0129]
[0102] The initial fastening has been described in the specific case where the insertion direction F is directed from the rotating assembly 38 towards the front face 190 of the cam 120. Alternatively, the cam 120 is inserted into the body 30 via the rear opening 60 and not via the front opening 58. In this case, the direction F is in the opposite direction. However, the teaching given in this text can be transposed to this case where the cam 120 is inserted via the rear opening 60.
[0130]
[0103] Other embodiments of the initial fixing are possible. For example, the initial fixing 290 may additionally include an annular groove formed inside the housing 56 or the cam 120, into which an O-ring identical to the seal 160 is received. In the mounted position, the O-ring is compressed against a cylindrical face located opposite the groove. Thus, this O-ring ensures a seal between the cam and the housing. Furthermore, in this embodiment, since the angular position of the cam is maintained by the O-ring, it is no longer necessary for the hooks 294 to be shaped to rub continuously against the ring 292.
[0131]
[0104] Alternatively, the initial fixing does not ensure a seal between the cam 120 and the housing 56. In this case, the O-ring can be replaced by one or more elastic strips interposed between the housing 56 and a cylindrical section of the cam 120. Each of these strips rubs against a cylindrical section of the cam to maintain the angular position of the cam as long as no torque exceeding the predetermined threshold S c is not applied to this cam.
[0132]
[0105] The initial fixing may include a keying feature that allows only one angular position of the cam 120 inside the housing 56 when the cam is in its mounted position. For example, for this purpose, the keying feature includes:
[0133] - one or more horizontal ribs made in one of the housing 56 and the outer peripheral face of the cam 120, and - one or more corresponding horizontal grooves made in the other of the housing 56 and the outer peripheral face of the cam 120.
[0134] When the cam is inserted into the housing 56, the ribs are received within the grooves, thus imposing a precise angular position of the cam within the housing. These ribs and grooves also prevent any rotation of the cam within the housing 56 in its mounted position. In such an embodiment, it is not possible to adjust the angular position of the cam 120. In this case, some elements of the adjustment mechanism, such as the lever 114, the through hole 170, and the asperity 172, can be omitted. This type of implementation therefore does not allow for very precise adjustment of the value returned by the sensor 40.
[0135]
[0106] In another embodiment, in its mounted position, the cam is entirely located inside the housing 56 and can rotate about the axis 6. Furthermore, some elements of the adjustment mechanism, such as the lever 114, the through hole 170, and the asperity 172, are omitted. In this case, the initial fixing 112 still allows adjustment of the angular position of the cam 120. To do this, the cam must be rotated manually inside the housing 56 in the absence of the assembly 38. Thus, in this case, adjustment of the angular position of the cam 120 is only possible after removing the rotating assembly 38 or the plate 64 to access the front face 190 of the cam 120.
[0136]
[0107] The variants of the two preceding paragraphs illustrate the fact that the initial fixing 110 or 260 can be implemented simply to simplify the assembly of the cam inside the housing 56 and independently of a reference position adjustment mechanism.
[0137]
[0108] Variants of the adjustment mechanism:
[0138]
[0109] The friction element can also be replaced by a spring that continuously forces the cam 120 towards an initial angular position. The adjustment of the cam's angular position is then made from this initial angular position. In this case, the lever's position must be locked when it is not being moved by an operator. Such a locking of the lever's position is illustrated by the case where the lever has an adjusting screw such as screw 176. The spring is, for example, a spiral spring wound around the axis 6, one end of which is fixed to the cam 120 and the other to the body 30.
[0110] Other embodiments of the mechanical connection between the lever and the cam are possible. Thus, alternatively, this mechanical connection is a rack and pinion connection. For this, by way of illustration, screw 176 is replaced by a worm gear, and teeth are provided on the outer periphery of the cam 120.These teeth mesh with the worm gear threads so that when the worm gear is rotated, it causes the cam to rotate about axis 6. The worm gear extends in a direction perpendicular to axis 6, so even if torque is applied to cam 120, it cannot rotate because its angular position is fixed by the interaction between the cam teeth and the worm gear threads. Furthermore, this design allows cam 120 to move in the right direction (R) and, conversely, in the opposite direction.
[0139]
[0111] Another variant of this mechanical linkage is obtained by replacing the lever 286 with an adjusting wheel mounted to rotate about an axis of rotation fixed to the body 30 and parallel to the axis 6. For example, this wheel has teeth and the cam has corresponding teeth on its outer periphery which mesh with the teeth of the wheel. Thus, when an operator manually turns the wheel, this moves the cam 120 in rotation about the axis 6.
[0140]
[0112] The friction member 160 can be omitted when the lever is connected to the cam via a mechanical linkage which already locks the angular position of the cam 120. An example of such a mechanical linkage is the rack and pinion linkage described previously.
[0141]
[0113] Alternatively, the through hole 284 is omitted. In this case, the lever 286 is arranged to pass through either the front opening 58 or the rear opening 60. For example, the lever 286 is fixed to the rear face 122 of the cam and this lever passes through the rear opening 60. In this case, when the rotating assembly 38 is mounted on the cam 120 and before the plate 64 is mounted, it is still possible to rotate the lever, which remains accessible through the rear opening. Such an alternative is particularly suited to embodiments of the measuring system that comprise only one measuring module.
[0142]
[0114] Other variants:
[0143]
[0115] The bearing 36 can be made differently. For example, the bearing 36 can be a roller bearing or a plain ring without a bearing.
[0116] The housing 56 is not necessarily through-hole. In this case, the rear opening 60 is omitted and a hole is provided in the body 30 to allow the wires 102 to exit and to inject the curable material on the rear face 122 of the cam 120 in order to fix this cam 120 onto the body 30 without any degree of freedom.
[0144]
[0117] The positions of the magnet and the transducer can be reversed. Thus, alternatively, the permanent magnet is contained in the stationary portion 92 and the transducer is contained in the rotating portion 90.
[0145]
[0118] Other embodiments of the transducer are possible. For example, the tunneling magnetoresistive element can be replaced by another magnetic transducer such as a Hall effect sensor. The angular sensor may also not use the orientation of a magnetic field to determine the angular position of the assembly 38. For example, the sensor may be a capacitive sensor that has electrodes in both its stationary and rotating portions. The rotation of the rotating assembly then changes the surface area of the opposing electrodes, which changes the capacitance. The angular sensor may also be an inductive or mechanical sensor. A suitable mechanical sensor is, for example, a potentiometer equipped with a rotating shaft and a fixed base. The distal end of the shaft is fixed, without any degrees of freedom, to the rotating assembly 38 so as to be driven in rotation by this rotating assembly.The shaft thus constitutes the rotating portion of the sensor. The base of the potentiometer then forms the stationary portion of the angular sensor.
[0146]
[0119] Other embodiments of the permanent fastening 200 are possible. For example, alternatively, the permanent fastening is achieved using screws that pass through the body 30 and each is driven into the cam 120. To allow the screws to be driven into the cam 120 at all possible angular positions of this cam 120, the screws are self-tapping or self-drilling screws. To facilitate driving the screw tip into the cam 120, the cam can be made of plastic or another similar material.
[0147]
[0120] In a simplified embodiment, the permanent fixing 200 is omitted. This is possible because the friction element alone already allows the angular position of the cam 120 to be locked. In this embodiment, the angular position of the cam 120 can be adjusted at any time during the operation of the measuring system. In this case, the threshold S c can be chosen larger to keep the 120 cam locked in rotation even in the presence of significant vibrations and / or accelerations.
[0148]
[0121] The haptic device 202 can be implemented differently. For example, several instances of the housing 204 can be arranged in the assembly 38 in order to detect several specific angular positions of this assembly 38 and produce a notching effect. In this latter case, the haptic device 202 can also be configured to maintain, in the absence of external stimulation, the utensil 4 in each of these specific angular positions. In another variant, the pin 206 is replaced by a ball.
[0149]
[0122] In a simplified embodiment, the haptic device 202 is omitted.
[0150]
[0123] Many different embodiments of the return mechanism 210 are possible. For example, instead of using a torsion spring, it is possible to use elastomer blocks or helical springs. The return mechanism 210 can also be omitted.
[0151]
[0124] The measurement system has been described so far in the specific case where there is triple redundancy in the measurement of the angular position a. However, what has been described also applies to the case of a simpler measurement system where there is no measurement redundancy. Thus, alternatively, the measurement system comprises only a single measurement module.
[0152]
[0125] In another embodiment, the different measuring modules are not structurally identical to each other. For example, each measuring module has an adjustment mechanism similar to those described above, but these modules differ from each other in other characteristics. For example, as illustrated in the case of measuring system 2, some measuring modules may be equipped with a haptic device and others may not. Some measuring modules may have a return mechanism and others may not. In another embodiment, the angular sensor of each module uses a different technology than that implemented in the angular sensor of another module.Thus, one module may use an angular sensor incorporating a tunnel magnetoresistive element, while another measuring module uses an angular sensor incorporating a Hall effect transducer, a capacitive transducer, an inductive transducer, or a potentiometer. When different angular sensor technologies are used, it is generally also necessary to perform electronic calibration of the signals generated by these different angular sensors to ensure they are identical for the same inclination of the utensil.
[0153]
[0126] The utensil is not necessarily a wheel. It may also be a lever, a handle, a grip or any other part that can be moved directly by hand by a human being.
[0154]
[0127] The utensil is not necessarily moved by a human hand. It can also be moved, for example, by a human foot. It can also be moved by a robot or any other mechanical object. Thus, the teaching provided here in the context of a human-machine interface can also be implemented in other contexts such as, for example, measuring the angular position of one part relative to another part.
[0155]
[0128] Several of the variants described above can be combined in the same embodiment.
[0156]
[0129] Chapter IV: Advantages of the embodiments described:
[0157]
[0130] Advantages of initial fixation
[0158]
[0131] The initial fixing of the cam inside the housing is particularly simple, as it is sufficient to push the cam 120 in the insertion direction F to mount it inside the body 30. In particular, this initial fixing can be carried out without tools. Moreover, this initial fixing allows for precise positioning of the cam 120 inside the housing 56. Indeed, by cooperating with the frustoconical face 56, the seal 160 constantly forces the cam 120 in the direction F. Thus, the seal 160 makes it possible to keep the shoulder 150 of the cam bearing against the corresponding shoulder 154 in the body. Thanks to this, the axial position of the cam 120, and therefore of the stationary portion 92 of the sensor 40, inside the housing 56 is precise. Since the seal 160 is toroidal, the cam 120 is also correctly centered on the axis 6 of revolution of the housing 56.Finally, the O-ring 160 of the initial fixing, in addition to holding the mounted cam inside the housing, also ensures the seal between the housing 56 and the cam 120 without the need for another sealing gasket.
[0159]
[0132] The fact that the initial fixing allows rotation of the cam on the axis 6 enables adjustment of the angular position of the cam 120, and therefore of the reference position, relative to the body 30, even though the cam 120 is already in its mounted position. This mechanical adjustment of the reference position eliminates the need for an electronic calibration circuit, which would perform the same adjustment by modifying the electrical signal generated by the angular sensor 40. Furthermore, once this adjustment is complete, the friction of the seal 160 on the frustoconical face 156 locks the set angular position. This simplifies the adjustment of the reference position relative to the body.
[0160]
[0133] The adjustment mechanism allows the angular position of the cam 120 to be set while the sensor 40 and the rotating assembly 38 are already mounted on the body 30. This allows the reference position to be adjusted to correspond to a predetermined angular position of the rotating assembly 38 using the measurement from the sensor 40. Furthermore, this adjustment mechanism is simple because it does not require any additional element, other than the O-ring 160, to lock the angular position of the cam 120 when no force is applied to the handle. Indeed, the O-ring of the initial mounting already performs this function.
[0161]
[0134] The fact that the angular position of the cam 120 is adjusted using an adjusting screw 176 allows for precise adjustment of the angular position of the cam 120. This adjustment is all the more precise because the friction of the O-ring 160 on the frustoconical face 156 constantly presses the asperity 172 against the end 180 of the screw 176 when the latter is screwed into the hole 170. By proceeding in this way, that is to say by screwing the screw 176 into the hole 170, there is no play in this adjustment mechanism, which improves the precision of the adjustment of the angular position of the cam.
[0162]
[0135] When the measuring module also includes the permanent fixing 200 of the cam, the initial fixing simplifies and makes the manufacture of the measuring module more reliable since the cam is held in position inside the body even before the implementation of the permanent fixing.
[0163]
[0136] When the permanent fixing has a curable material injected on the rear face 122 of the cam 120, the O-ring 160 prevents this curable material from reaching and damaging the bearing 36 or the rotating assembly 38.
[0164]
[0137] The fact that the cam 120 is entirely located inside the housing 56 in the mounted position allows the overall size of the initial fixing to be reduced since no element of this initial fixing protrudes from the housing 56. This therefore allows the overall size of the measuring module to be reduced.
[0165]
[0138] The presence of bearings 76, 194 only on the cam 120 and on the rotating assembly 38 allows a precise air gap to be obtained between the rotating portion 90 and the stationary portion 92 of the sensor 40 independent of the axial position of the cam 120 inside the housing 56.
[0166]
[0139] Using a tunnel magnetoresistive (TMM) transducer provides a directly usable electrical signal without the need for electronic components to shape it. Furthermore, the TMM's sensitivity to changes in the orientation of the permanent magnet is very high, thus increasing the sensitivity of the sensor 40. However, the reference position must be adjusted with high precision.
[0167]
[0140] The fact that the measuring system comprises several measuring modules in which the angular positions of the cams have been adjusted so that the different angular sensors generate identical electrical signals makes it possible to obtain truly redundant and interchangeable measuring modules. Therefore, no electronic calibration of the electrical signals generated by the different modules is necessary to make them identical.
[0168]
[0141] Advantages of the adjustment mechanism:
[0169]
[0142] The lever allows the reference position to be adjusted from outside the body 30, and therefore after the sensor 40 and the rotating assembly 38 have been assembled on the body. Thus, the measurements from the sensor 40 for a given angular position of the rotating assembly can be used to verify that, after rotation of the cam, the desired reference position has been reached. Furthermore, the cam 120 is housed inside the casing, which reduces the overall size of this adjustment mechanism.
[0170]
[0143] The fact that the initial fixing only has a friction element 160 to maintain the angular position of the cam simplifies the realization of the adjustment mechanism.
[0171]
[0144] When the friction element is an O-ring 160 interposed between the housing and the cam, in addition to fulfilling the functions of the friction element, this O-ring ensures a seal between the housing 56 and the cam 120. The fact that the same seal is Tl
[0172] used to perform two different functions, it simplifies the architecture of the measurement system.
Claims
28 Demands 1. A system for measuring an angular position relative to a reference position, this system comprising a first module (20, 22, 24) for measuring the angular position relative to the reference position, this first measuring module comprising: - a fixed body (30) comprising a housing (56) centered on an axis (6) of revolution, - a rotating assembly (38) mounted for rotation on the axis of revolution, - an angular sensor (40) which generates an electrical signal representative of the angular position of the rotating assembly relative to the reference position, this angular sensor comprising for this purpose: - a rotating portion (90) fixed without any degree of freedom on the rotating assembly, and - a stationary portion (92), - an initial fixation (110; 260) capable of holding the stationary portion of the angular sensor fixed to the fixed body, characterized in that the initial fixation comprises: - a cam (120) on which the stationary portion of the sensor is fixed without any degree of freedom, this cam being mounted inside the housing, - by moving in the direction of insertion of the cam inside the housing, a first shoulder (150) then an annular groove (152; 262), both centered on the axis of revolution and both formed in the cam and the body, - by moving in the direction of insertion, a second shoulder (154) then a frustoconical face (156; 266), both centered on the axis of revolution and both formed in the cam and the body, the second shoulder bearing on the first shoulder and the frustoconical face being located at the same level as the annular groove and flaring out in the direction of insertion, and - an O-ring (160) of friction received inside the annular groove and bearing against the frustoconical face to constantly stress the cam in the direction of insertion.
2. System according to claim 1, wherein: - the cam (120) is able to be arranged, inside the housing, in different angular positions on the axis of revolution to adjust the reference position relative to the body, and - as long as no other fixing of the angular position of the cam has been implemented, the initial fixing allows an angular deflection of the cam on the axis of revolution against the friction force exerted by the o-ring (160) on the frustoconical face (156; 266).
3. Measurement system according to claim 2, wherein the first module comprises a reference position adjustment mechanism (110; 270; 280) capable, as long as no other fixing of the angular position of the cam has been implemented, of rotating the cam on the axis of revolution after the cam has been mounted inside the housing using the initial fixing and after the sensor and the rotating assembly have been mounted on the body, this adjustment mechanism comprising the initial fixing and a lever (114; 282) accessible from outside the fixed body and mechanically connected to the cam to drive the cam in rotation on the axis of revolution when the lever is moved.
4. System according to claim 3, wherein: - The adjustment mechanism includes: - an asperity (172; 272) eccentric with respect to the axis of revolution and fitted on the cam, - a through hole (170) cut into the body which opens, on one side, into the interior of the housing opposite the asperity, and, on the opposite side, onto an external face of the body, this through hole having a thread, - the handle includes an adjustment screw (176) screwed into the thread of the through hole, this adjustment screw having a head (178) rotatably movable from outside the body to screw the adjustment screw inside the through hole and an end (180) adapted to bear against the asperity of the cam when the adjustment screw is screwed inside the through hole to push the asperity and thus rotate the cam on the axis of revolution.
5. System according to any one of the preceding claims, wherein the system also includes another fixing (200), mechanically separate from the initial fixing, adapted to prevent any movement of the cam relative to the body.
6. System according to claim 5, wherein: - the cam has a front face (190) facing towards the rotating assembly and, on the opposite side, a rear face (122), - the O-ring of the initial fixing is located between the front and rear faces of the cam, and - the other fixing (200) has a hardenable material cast between the body and the cam on the rear face side of this cam.
7. System according to any one of the preceding claims, wherein the cam is entirely located inside the housing.
8. System according to any one of the preceding claims, wherein the first module comprises a bearing (36) to permit the rotation of the rotating assembly about the axis of revolution, this bearing being only interposed between a first bearing surface (194) integral with the cam and a second bearing surface (76) integral with the rotating assembly.
9. System according to any one of the preceding claims, wherein one of the rotating portion (90) and the stationary portion (92) of the sensor comprises a permanent magnet and the other a tunnel magnetoresistance capable of generating an electrical signal representative of the angular position of the permanent magnet.
10. A system according to any one of the preceding claims, wherein this system comprises: - a second module (20, 24) for measuring the angular position relative to the reference position, this second measurement module being structurally identical to the first measurement module, - a synchronizing arm (12) which mechanically connects, without any degree of freedom, the rotating assemblies (38) of the first and second measuring modules so that the rotation of the rotating assembly of the first measuring module systematically corresponds to an identical rotation of the rotating assembly of the second measuring module, and - the angular position of the cam of the first measuring module is different from the angular position of the cam of the second measuring module and the signals generated by the angular sensors of the first and second measuring modules are identical regardless of the inclination of the synchronization arm.
11. A method for manufacturing a measuring system according to any one of the preceding claims, wherein the method comprises a step (230) of assembling a first measuring module, this step of assembling the first measuring module comprising: - the supply (232) of a fixed body comprising a housing centered on an axis of revolution, - the supply (232) of a rotating assembly suitable for mounting in rotation on the axis of revolution, - the supply (232) of an angular sensor capable of generating an electrical signal representative of the angular position of the rotating assembly relative to the reference position, this angular sensor comprising for this purpose: - a rotating portion capable of being fixed without any degree of freedom onto the rotating assembly, and - a stationary portion, - the provision (232) of an initial fixing suitable for maintaining the stationary portion of the angular sensor fixed to the fixed body, characterized in that: - the initial fixing supplied (232) includes: - a cam on which the stationary portion of the sensor is fixed without any degree of freedom, this cam being mounted inside the housing, - by moving in a direction of insertion of the cam inside the housing, a first shoulder then an annular groove both centered on the axis of revolution and both formed in one of the cam and the body,32 - by moving in the direction of insertion, a second shoulder and then a frustoconical face, both centered on the axis of revolution and both fitted into the other of the cam and the body, the second shoulder being able to bear against the first shoulder and the frustoconical face being able to be located at the same level as the annular groove and flaring out in the direction of insertion, and - a friction O-ring received inside the annular groove and adapted to bear against the frustoconical face to constantly urge the cam in the direction of insertion, then - mounting (234) the cam on the body by pushing it into the housing following the insertion direction until the first and second shoulders come into contact with each other.
12. A method according to claim 11, wherein: - When the cam is supplied, it is suitable for being positioned, inside the housing, at different angular positions on the axis of revolution to adjust the reference position relative to the body. - the assembly phase of the first measuring module includes mounting (238) the sensor and the rotating assembly onto the body, and - after the assembly phase of the first measuring module, the process includes the adjustment (248) of the angular position of the cam on the axis of revolution by exerting a mechanical torque on the cam.
13. Method according to claim 12, wherein the method comprises, after adjusting the angular position of the cam on the axis of revolution, fixing (250) the cam on the body, using another fixing mechanically distinct from the initial fixing, to prevent any movement of the cam relative to the body.