CN101657694A

CN101657694A - Cylinder position sensor and cylinder incorporating the same

Info

Publication number: CN101657694A
Application number: CN200780050586A
Authority: CN
Inventors: K·希达亚特
Original assignee: Stoneridge Control Devices Inc
Current assignee: Stoneridge Control Devices Inc
Priority date: 2006-12-13
Filing date: 2007-12-13
Publication date: 2010-02-24

Abstract

A cylinder position sensor a cylinder including the same. At least one magnet is coupled to a component of the cylinder. A sense element provides an output in response to magnetic flux from the magnet. The output of the sense element varies with the position of a piston and piston rod with respect to a cylinder barrel.

Description

Cylinder position sensor and the cylinder that comprises this cylinder position sensor

[0001] the application requires in the U.S. Provisional Application No.60/869 of submission on Dec 13rd, 2006,805, the U.S. Provisional Application No.60/871 that submitted on Dec 22nd, 2006,622, the U.S. Provisional Application No.60/916 that submitted on May 4th, 2007, the U.S. Provisional Application No.60/975 that on September 26th, 000 and 2007 submitted to, 328 right of priority, the content of above-mentioned application is contained in this paper by reference.

Technical field

[0002] disclosure generally relates to position transducer, relates in particular to the position transducer that uses with cylinder.

Background technology

[0003] using assembly of actuator control is known with respect to the position of another assembly with moving.Many actuators (for example hydraulic cylinder, pneumatic linear actuator and analog) comprise cylinder and piston rod, and piston rod has the piston that connects with it.When introducing actuation force (for example, but being not limited to pressurization hydraulic fluid or pressurized air), cylinder and piston/bar relative to each other move.

[0004] in many application, may expect to know the position of bar with respect to cylinder.The basic of mechanical operation normally controlled in the control of bar position.In order to obtain to use this control of traditional feedback control technology, usually need absolute position or the speed of sounding rod with respect to cylinder.

Description of drawings

[0005] in conjunction with the accompanying drawings, with reference to following detailed, wherein identical Reference numeral refers to identical part:

Fig. 1 shows an exemplary embodiments according to system of the present disclosure;

Fig. 2 shows the typical piston rod that comprises according to an exemplary configurations of permanent magnet of the present disclosure and sensing element;

Fig. 3 is the curve map of the sense field relevant with embodiment shown in Fig. 2 with respect to the throw of lever/position;

Fig. 4 shows another the typical piston rod that comprises according to the exemplary configurations of permanent magnet of the present disclosure, sensing element and degaussing coil;

Fig. 5 shows another the typical piston sense that comprises according to the exemplary configurations of permanent magnet of the present disclosure and sensing element;

Fig. 6 is the sectional view of embodiment shown in Fig. 5;

Fig. 7 shows another the typical piston rod that comprises according to the exemplary configurations of permanent magnet of the present disclosure;

Fig. 8 be with according to the curve map of the relevant sense field of piston position sensor of the present disclosure with respect to the throw of lever/position;

Fig. 9 shows according to another typical cylinder of the present disclosure;

Figure 10 is the sectional view that the permanent magnet of embodiment shown in Fig. 9 position is shown;

Figure 11 A-11D with the form of chart show according to permanent magnet of the present disclosure radially, straight line and axial magnetized;

Figure 12 shows according to another typical cylinder of the present disclosure;

Figure 13 is the end-view that the permanent magnet position of embodiment shown in Figure 12 is shown;

Figure 14 shows according to another typical cylinder of the present disclosure;

Figure 15 is the end-view that the permanent magnet position of embodiment shown in Figure 14 is shown;

Figure 16 shows according to another typical cylinder of the present disclosure;

Figure 17 is the end-view that the permanent magnet position of embodiment shown in Figure 16 is shown;

Figure 18 is the detailed view of the end sections of bar shown in Figure 16;

Figure 19 shows according to another typical cylinder of the present disclosure;

Figure 20 shows the part according to the closed loop magnetic line of force in the typical cylinder of the present disclosure;

Figure 21 shows the part that comprises permanent magnet according to cylinder of the present disclosure, and described permanent magnet is located in the chamber that is formed in the bar;

Figure 22 shows the part that comprises permanent magnet according to cylinder of the present disclosure, and described permanent magnet is located at and is used for piston is fixed to nut on the bar;

Figure 23 is the end-view of nut shown in Figure 22;

Figure 24 shows according to another typical cylinder of the present disclosure;

Figure 25 is the end-view of embodiment shown in Figure 24;

Figure 26 shows according to another typical cylinder of the present disclosure;

Figure 27 is the end-view of embodiment shown in Figure 26;

Figure 28 shows according to another typical cylinder of the present disclosure;

Figure 29 is the end-view of embodiment shown in Figure 28;

Figure 30 shows according to another typical cylinder of the present disclosure;

Figure 31 shows according to another typical cylinder of the present disclosure;

Figure 32 is the end-view of embodiment shown in Figure 31;

Figure 33 is the detailed view of the end sections of bar shown in Figure 31;

Figure 34 shows according to another typical cylinder of the present disclosure;

Figure 35 shows a kind of exemplary configurations according to sensing element in the system of the present disclosure with the form of chart;

Figure 36 is the side view of embodiment shown in Figure 35;

Figure 37 shows another exemplary configurations according to sensing element in the system of the present disclosure with the form of chart;

Figure 38 is the side view of embodiment shown in Figure 37;

Figure 39 shows the exemplary embodiments that can be used on according to the sensor electrical component in the system of the present disclosure;

Figure 40 is the output voltage relevant with the component of sensor electrical shown in Figure 39 curve map with respect to cylinder position;

Figure 41 is the side view according to another typical cylinder of the present disclosure;

Figure 42 is the sectional view of the part of cylinder shown in Figure 41;

Figure 43 is the side view according to another typical cylinder of the present disclosure;

Figure 44 is the side view according to another typical cylinder of the present disclosure;

Figure 45 is according to the skeleton view that comprises another typical cylinder of outer cover of the present disclosure;

Figure 46 is the skeleton view that can be used on according to the typical piston in the cylinder of the present disclosure;

Figure 47 has removed the skeleton view of cover part for piston shown in Figure 46;

Figure 48 is the exploded view that can be used on according to another the typical piston in the cylinder of the present disclosure;

Figure 49 is the partial exploded view of piston shown in Figure 48;

Figure 50 is the sectional view of piston shown in Figure 48;

Figure 51 is another sectional view of piston shown in Figure 48;

Figure 52 comprise with according to the curve map of the relevant sensing radial field of typical cylinder position sensor of the present disclosure with respect to the throw of lever/position;

Figure 53 comprise with according to the curve map of the relevant sensing axial field of typical cylinder position sensor of the present disclosure with respect to the throw of lever/position;

Figure 54 is the exploded view that can be used on according to the magnet assembly in the piston of the present disclosure;

Figure 55 is the partial exploded view that comprises the typical piston of magnet assembly shown in Figure 54;

Figure 56 is the skeleton view that can be used on according to another the typical piston in the cylinder of the present disclosure;

Figure 57 is the skeleton view that can be used on according to another the typical piston in the cylinder of the present disclosure;

Figure 58 is the exploded view that can be used on according to another the typical piston in the cylinder of the present disclosure;

Figure 59 is the skeleton view of piston shown in Figure 58;

Figure 60 shows another exemplary embodiments that can be used on according to the sensor electrical component in the system of the present disclosure;

Figure 61 is that the sensor relevant with the component of sensor electrical shown in Figure 60 exported the curve map with respect to cylinder position;

Figure 62 is the output voltage relevant with the component of sensor electrical shown in Figure 60 curve map with respect to cylinder position;

Figure 63 shows another exemplary configurations according to the sensing element in the system of the present disclosure with the form of chart;

Figure 64 comprises the curve map of the sensing magnetic field relevant with the layout of pairing sensing element among Figure 63 with respect to cylinder position;

Figure 65 comprises the curve map of the arc tangent of the sin/cos output relevant with the layout of pairing sensing element among Figure 63;

Figure 66 comprises the curve map of the sensing magnetic field relevant with the layout of pairing sensing element among Figure 63 with respect to cylinder position;

Figure 67 comprises the curve map of the derivative in the sensing magnetic field relevant with the layout of pairing sensing element among Figure 63 with respect to cylinder position.

Embodiment

[0006] according to the disclosure, showing is the position of definite piston rod and the various embodiment that are connected to the cylinder position sensor of the element on it.Described cylinder can comprise any cylinder design known in the art, for example, but be not limited to, comprise the hydraulic pressure of at least one cylinder barrel and at least one bar/piston and pneumatic piston actuater etc., described cylinder barrel and described bar/piston are by actuating fluid (for example, but be not limited to hydraulic fluid or pressurized air) and relative to each other move.Those skilled in the art will recognize that according to cylinder position sensing system of the present disclosure and also can be used in other application.

[0007] as describing in detail more, cylinder position sensing system described here can comprise the use of one or more sensing elements, and the output of described sensing element can be used for determining/estimate the signal of the position of cylinder rod.Although listing of non-exclusionism, sensing average can comprise one or more hall effect sensors, magnetic flux transducer, MR sensor, GMR sensor or any other magnetic sensor.As everyone knows, digital hall effect sensor can be configured to provide digital signal, the numeral when wherein its output can be included in the predeterminated level that reaches magnetic flux " 1 " output and the digital " 0 " when not reaching the magnetic flux predeterminated level.Certainly, the value of output signal also can be opposite.Alternatively, the output of sensor can comprise simulating signal.For easy and clear for the purpose of, the cylinder of cylinder position sensing system part can all not illustrate, this conforms to those skilled in the art's knowledge.

[0008] Fig. 1 shows according to canonical system of the present disclosure, comprises the cylinder 102, position transducer 106 and the control system 108 that are used for mobile moving element 104.Cylinder 102 illustrates with the form of sectional view, comprises cylinder barrel 110, bar 112, piston 114 and bar guide 116.Piston 114 is arranged in the cylinder barrel 110 with along the axis to-and-fro movement.Piston 114 is divided into two

chamber

118a and 118b with cylinder barrel 110.Piston, bar, tube and/or bar guide can be made by iron content or nonferrous material, for example steel.

[0009] end of piston rod 112 is fixed on the piston 114, and extends along its axis of movement.The other end of piston rod 112 extends tube 110 by bar guide 116, and can be directly or sound barrier be connected on the moving element 104.Cylinder barrel comprises in known manner and is used for the passage (not shown) of fluid from the turnover of chamber 118a and 118b.For example, the variation that the coupling arrangement by known fluid control gear and cylinder is applied to the hydrodynamic pressure in the chamber causes that piston and bar are with respect to the moving of cylinder barrel, to cause the controlled motion of moving element.

[0010] for the controlled motion of moving element is provided, position transducer 106 can be connected on the cylinder 102 position with sensing piston rod 112.Position transducer can provide the output of the position of indicator piston bar 112 to control system.The motion that control system can be come the control piston bar in response to the control of the output of the position transducer Fluid Volume by for

example introducing chamber

118a and 118b.

[0011] described moving element can be and is configured to any element of moving by piston, for example the scraper bowl part of shovel loader, excavator.In one embodiment, for example, can be used on repeatedly according to position transducer of the present disclosure and excavate/to dump in the application repeatedly.For example, be loaded into a pile material on the dump car or the operator of shovel loader on other transportation equipment or excavator can set and makes scraper bowl partly enter the tap point of bing and dumping a little on transportation equipment.Described tap point can be determined from sensor output with dumping a little.Described operator can concentrate machinery is placed on right positions, and hydraulic system partly moves on to scraper bowl from the excavation or the tipping height on the right side that the sensor output that offers control system 108 is determined.

[0012] in another embodiment, connection is with the gps system that strengthens, and hydraulic system can obtain input from the computer model of sensor and the levelling of the land scheme or the scheme of excavation.Control system 108 can be come control tool in response to described input, and (for example, scraper bowl) position so that the described gradient or groove face correctly move, need not the secondary finishing.

[0013] in another embodiment, the operator in the traction engine can set multiple performance variable, comprises the degree of depth, uses and carry out other variable by the place.The end of being expert at can use button or other control that all instruments are retracted from ground with revolution.After turning back to the place, the operator can use a control that all hydraulic operations are carried out to set and return the point identical with the front, uses the sensor output to control system 108, and handles row in opposite direction.

[0014] in another embodiment, the spiral drill location is if spiral drill mislays, cereal can miss transportation equipment and be damaged so on the transportation equipment of harvester next door operation.In addition, spiral drill vibration is remained on the transportation equipment simultaneously, and fill transportation equipment to such an extent that more fill it up with and make that its operation is more effective.Control system 108 can be with spiral drill location in position and/or in response to the twist bit position signalling that spiral shell provides according to the sensor of the present disclosure spiral drill that vibrates.

[0015] with reference now to Fig. 2, show a exemplary embodiments according to cylinder position sensor of the present disclosure, wherein at least one permanent magnet 202 (for example, a pair of

permanent magnet

202a and 202b) (for example be connected to or otherwise be fixed on the bar 112, but be not limited to, the end regions 206a and the 206b of bar 112), and along with bar 24 motions.One or more sensing element 920-1,920-2 ... 920n can produce magnetic field that expression permanent magnet 202 produces radially and/or tangential component, and can be used to determine the position of bar 112.Especially, when

magnet

202a and 202b moved more near sensor 920, sensor output can increase, for example, in the mode of linearity, and, when they during away from sensor, sensor output can reduce, for example, in the mode of linearity.Therefore, sensor output provides the expression with respect to the position of cylinder rod of piston and bar.

[0016] according to an embodiment, cylinder position sensing system 200 comprises one or more annular

permanent magnet

202a, 202b, and described annular

permanent magnet

202a, 202b can be connected on the one or

more end

206a and 206b of bar 112.Though requirement so only, otherwise be not restriction of the present disclosure, because annular permanent magnet 202 can be known the bolt (not shown) on the bar 112, so annular permanent magnet is preferred.But permanent magnet 202 can be set as those skilled in the art known any other shape or structure, includes, but are not limited to disc permanent magnet and analog.

[0017] with reference to figure 3, show cylinder position sensing system 200 one or more sensing elements 920 radially export curve map 300 with respect to the throw of lever.As shown in the figure, the output of the sensor of system 200 can represent the range of linearity 302 that the position of bar is determined in fully big being used

for.Nonlinear area

304a, 304b near the end also can come linearization by sensor electrical component and tracing table.

[0018] in some applications, need and/or cylinder position sensing system 200 that expectation can high-res (for example, 1mm resolution).Although use cylinder position sensing system 200 can relatively easily satisfy this demand than quarter butt 112, can be difficult more to the cylinder position sensing system 200 that uses stock 112.For example, cylinder position sensing system 200 may need to represent and the bar 112 of 2 meters long (2000mm) is divided into 2000 parts resolution, to keep the resolution of 1mm.Although can use the more sensing element 920 of high-res (for example, Hall element), for 2 meters bar, many sensing elements may not have sufficiently high resolution.Only be schematic purpose, typical Hall element 920 can send the resolution one of (1024) of 10 bits.

[0019] application that has higher resolution for expectation cylinder position sensor 200, cylinder position sensing system 200 can comprise two or more sensor 920-1,920-2 ... 920n, wherein each sensing element 920-1,920-2 ... the part of the length of 920n sounding rod 112, next then sensing element 920-1,920-2 ... 920n takes over.These sensing elements 920-1,920-2 ... 920n is operable in different gains.

[0020] the cylinder position sensing system potential problems is the influences that are subject to the external magnetic field, for example the magnetic field that is produced by the ox bar magnet.The ox bar magnet uses in the farm, is fed to cow to be placed in first stomach of cow.The ox bar magnet is collected sharp-pointed object, and for example nail and analog are to prevent the injury to the cow interior tissue.Therefore, the farmer usually makes the ox magnetic field in their pocket be in the field.When the ox bar magnet contacts with the bar 112 of cylinder position sensing system, may report the field of sensing by mistake, and interrupt accurate location sensing.

[0021] in cylinder position sensing system 200, when the ox bar magnet contacts with bar 112 (having the

magnet

202a and 202b that are connected to end 206a or 206b) or bar when being arranged in the external magnetic field, after removing ox bar magnet or external magnetic field, may have residual magnetic field.In order to address this problem, can be in sensor element housing 404 or bar 112 near combination degaussing coil 402 as shown in Figure 4.Fixedly sinusoidal frequency encourages degaussing coil 402, to give bar 112 degaussings before detection sensor 920-1,920-2 registered location information.But the AC composition that the exhaust of position transducer soft copy is all, thereby only read the DC part of the field that causes by permanent magnet 202a and 202b.Most of hydraulic cylinders are made by the ferromagnetic material of magnetic sensor desired (but and nonessential).Alternatively, permanent magnet can be used as permanent demagnetizer with reference to as described in the figure 24 as following, so that remove when bar is removed and before sensor picks up main field from the source permanent magnet or reduce residual magnetic field.

[0022] another potential problems of cylinder position sensing system are, bar 112 may be crooked because of the load that operating period acts on the cylinder.The bending of bar 112 can change air gap between sensing element 920 and the bar 112/at interval, thereby changes the output of sensing element 920.For addressing this problem, can use a plurality of sensing elements 920 (for example, a plurality of sensing elements 920 around the circumference of bar 112 substantially equidistantly at interval, 180 degree separately for example) eliminate the influence of the bending of bar 12 fully.When sensing element 920-1 because of crooked rod 112 when near more, another sensing element 920-2 (for example, with respect to the first sensing element 920-1180 degree place) will be farther apart from bar 112.The output of these sensing elements 920 stack (for example, connecting and similar fashion by difference), the result has eliminated the constant outfield that bending error maybe may enter cylinder substantially.

[0023] in addition or alternatively, and the passing through of the bending of bar 112 " float,, sensing element 920 solves.For example, as shown in Fig. 5 and 6, sensor housing 404 can be connected on the bar 112, and can radially move along with bar 112.One or more sensing elements 920 can be connected on the sensor housing 404.Sensor housing 404 can comprise and have a plurality of ribs 604 () inside surface 602 for example, three or more ribs 604, the outside surface of described ribbed joint feeler lever 112 and keep basically/the fixing interval/distance between sensing element 920 and the bar 112.When bar 112 bendings, sensor housing 404 can move along with bar 112, and the air gap/interval between sensing element 920 and the bar 112 can keep substantial constant.

[0024] position of permanent magnet that is used to produce the field of sensed element 920 sensings can change according to being used for.For example, some double-acting cylinders can be contained in magnet the center of cylinder.For example, as shown in Figure 7,

permanent magnet

700a, 700b can be embedded in the inside of bar 112, near magnetic circuit, also make the elongation minimum of the bar 112 that the increase because of 700a, 700b causes with further.For example, bar 112 can comprise that the shoulder or the platform that extend radially outwardly from bar 112 usually go on foot zone 702.One or

more magnet

700a, 700b (for example, but being not limited to toroidal magnet) can be positioned at the every side/surperficial 704a and the 704b of shoulder 702.

[0025] according to another embodiment, except permanent magnet or alternative permanent magnet, bar can be included in the hard magnetic layer on the axle, overcomes the more stable output of external magnetic field with generation.Because steel is not done many magnetic merits because of its big quality under thin plated material, and the external magnetic field can magnetize the steel under electrodeposited coating and change sensor output, so exist under the situation of external magnetic field, hard magnetic layer is not worked.In addition, when the field that exists greater than its strong magnetic (Hc), plated material itself is understood degaussing.

[0026] according to an embodiment, the disclosure can solve these problems by give the bar degaussing when sensor is operated.Demagnetizing field can be enough by force giving the steel degaussing, but a little less than enough again, so that it does not give the plated material degaussing.Like this, have enough that the magnetic coating of hard (magnetic aspect) and the degaussing (for example, use degaussing coil or above-mentioned permanent demagnetizer) of bar combine, can solve the problem that steel is magnetized so if electroplate to be selected to.

[0027] high-res is supposed in many application usually, but only needs high-res along the length of cylinder in some field of advancing.Therefore, all cylinder position sensing system embodiment described here can have the high position sensing resolution in one or more zones and the low-res in one or more zones.For example, Fig. 8 is according to the curve map 804 of the sensor of typical cylinder position sensor of the present disclosure output with respect to the throw of lever.Curve 804 has represented compares a 800a and the sensing resolution zone, the 2nd 800b high position with higher slope with lower position sensing resolution zone 802.As mentioned above, can obtain high position sensing resolution by being provided with near the part that needs high-res at bar than the local more sensing element that needs low-res.

[0028] therefore, can comprise the one or more magnets that are connected to cylinder rod according to cylinder position sensor of the present disclosure, to produce magnetic field, the output of the substantially linear of indication rod position is set up in this magnetic field from one or more sensing elements.Radially and/or the normal field component can determine the bar position by sensed element sensing.Degaussing pulse and/or permanent magnet or be used for the magnetically described bar of purifying are to remove all residual magnetic field.

[0029] Fig. 9 shows another embodiment according to cylinder position sensor of the present disclosure.Exemplary embodiments shown in Fig. 9 shows hydraulic cylinder and comprises part according to sensor construction of the present disclosure.In addition, it will be understood by those skilled in the art that, show hydraulic cylinder with the form of simplifying to for the purpose of convenient the description.

[0030] in the embodiment of Fig. 9 and 10, magnet 906,908 is located in the hole that is formed at piston 114.

Magnet

906 and 908 is semicircle, and is arranged in the corresponding semi-circular hole of appropriate location, arranges with the circumferential section around bar 112.But, should be appreciated that the magnet that can use any amount., can perhaps can use the magnet of a circle around a plurality of littler magnets of all or part of layout of piston circumference.But described magnet can comprise any magnetic material that is enough to set up by the sensing magnetic flux of the sensor in using.In one embodiment, magnet can be the neodymium magnet.Can use traditional sintered magnet.

[0031] described magnet can be radially, straight line or axial direction magnet.For example, the arrow among Figure 11 A and the 11B shows radially magnetizing with straight line of magnet 906 and 908.Figure 11 C is the front elevation of

magnet

906 and 908, and the arrow in the sectional view of Figure 11 D shows the axial magnetized of magnet among Figure 11 C.For the conventional sintering magnet, the magnetization of straight line shown in Figure 11 b is simpler.Near cylinder end, for example in the respective grooves of cylinder rod guide 116 or in the separated sensor housing that connects around bar, can be provided for one or more sensors 920 of sensing magnetic flux, for example magnetic flux transducer.

[0032] for example, as shown in Figure 20,

magnet

906 and 908 magnetic flux can have by piston rod 112, bar guide 116 (or hold other element of the sensor), tube 110 and be back to the closed-loop path of magnet by piston 114.Sensor 920 can be arranged in the flux path or near, with at least a portion of sensing magnetic flux, and provide the output of expression from its flux level that passes through.When piston and bar moved more near sensor 920, sensor output can for example linear mode increase, and along with piston and bar away from sensor, sensor output can for example linear mode reduce.Therefore, sensor output provides the indication with respect to the position of cylinder barrel of piston and bar.In the described exemplary embodiments,, can omit sensor and sensor housing or bar guide here for conveniently illustrating.

[0033] magnet can be connected on piston or the bar directly or indirectly in any position with multiple structure.Figure 12-18 shows typical optional magnet structure.Figure 12-13 shows a plurality of magnet 908a that are arranged in piston 114 and directly contact with bar 112.Figure 14-15 shows and is positioned near a toroidal magnet 908b of piston 114 outside surfaces.

[0034] Figure 16-18 shows the one or more magnet 908c that are assembled in the bar.As shown in Figure 16 and 18, one or

more bar magnets

1602,1604 can be equally or are located at alternatively near the bar 112 in piston opposite end, for example, surpass the position of cylinder and sensor end.In the embodiment of Figure 16, along the direction magnetization magnet that is parallel to bar 112 axis, shown in arrow among Figure 18.As shown in Figure 19,

bar magnet

1602,1604 can use magnet retainer 1902 to be connected on the bar.The magnet retainer can be made of steel or nonferrous material.Figure 21 and 22-23 show other magnet installation site.As shown in Figure 21, one or more magnet 908d can be installed in the hole 210 of bar 112.As shown in Figure 22-23, one or more magnet 908e can be installed in the nut 2202 that is used for piston 114 is connected to bar 112.

[0035] Figure 24-25 shows an exemplary embodiments according to sensing system of the present disclosure, comprises near the one or more degaussing bodies (erasermagnets) 2402 in end that are positioned at cylinder barrel 110.As shown in the figure, a plurality of permanent magnets 2402 can lead to degaussing body retainer 2404 and remain in the appropriate location around the circumference of bar 112.When bar is removed, and before sensor picked up main field from the source permanent magnet, degaussing body 2402 can be removed residual magnetic field.The degaussing body can be magnetized along the direction away from sensor, so that the magnetic bias that overcomes the outfield to be provided, for example by being positioned on the bar or near ox bar magnet or the generation of other permanent magnet.

[0036] but the permanent magnet of setting up the sense field be used for determining the bar position can be located at other or optional position.For example, as shown in figure 26, can use 2602 operations of fixing magnet according to cylinder position sensor of the present disclosure.Shown in the exemplary embodiments, fixing magnet is positioned at from the axially extended outer cover in the end of tube 110 and extends on 2604, so that the magnetic flux by arrow 2606 expressions to be provided.The flux of fixed magnets 2602 can be sensed, to determine cylinder position, also can provide the magnetic bias that overcomes the outfield.

[0037] for example, as shown in Figure 28-29, can for example, be the cost among reduction bar and the non-rotary embodiment only around the part location of bar 112 circumference according to the permanent magnet 908f in the cylinder position sensor of the present disclosure.Equally, Figure 30 shows the layout that comprises magnet 3002, and for example, for double acting bar structure, magnet 3002 is connected on the piston 114a in the centre position of bar 112.

[0038] as shown in Figure 31-33, one or

more bar magnets

3102,3104 can be equally or be positioned at alternatively in the bar 112 with the piston opposite end near, and surpassing the end of bar guide, described bar guide can comprise one or more sensing elements of the field that is used to receive sensing magnet 908c.In the embodiment of Figure 31,

magnet

3102,3104 is magnetized along the direction that is parallel to bar 112 axis, shown in arrow among Figure 33.Figure 34 shows the exemplary embodiments that comprises coil 3402, and described coil 3402 is arranged on the coil holder 3404 around bar 112.The AC electric current that provides by coil can be used for eliminating or reduces residual magnetization in the bar 112.

[0039] Figure 35-38 shows and is used for one or more sensors 920 (for example, fluxgate sensor) are positioned near the bar 112 exemplary embodiments.As shown in the figure, sensor 920 can be positioned on one or more printed circuit board (PCB)s (PCB) 3502, for example, and in the groove of bar period of the day from 1 a.m. to 3 a.m. 116 or in the independent sensor housing.Sensor 920 can be different structure connect eliminating public and the signal that produces of enhancing magnet flux.Figure 35-36 shows a plurality of sensors 920 that are arranged in perpendicular on the PCB of bar 112 orientations.Sensor among Figure 35-36 is positioned on the PCB, extending through at least a portion of bar width, and usually perpendicular to the axis of bar 112.Figure 37-38 shows the sensor 920 on the PCB that is arranged in separately, and described PCB is perpendicular to the bar orientation, and around apart 180 degree of the circumference of bar.Sensor among Figure 35-36 is positioned on the PCB, always radially to extend with respect to bar 112.Can use other sensor and PCB structure according to the sensor output of expectation.

[0040] Figure 39 shows the typical electrical component that contains a plurality of sensors 920 with the block diagram form, and described sensor 920 is used for providing the expression can be in the output of the bar position of using according to system of the present disclosure.Shown in exemplary embodiments comprise main magnetometer 3902, controlled magnetometer 3904 and processor 3906.Controlled magnetometer 3902 can be configured to automatic gain control structure (for example, setting the control signal of dynamic range and skew in response to processor) driving sensor, for example fluxgate coil.This structure can be used for being provided at the output of the cylinder position scope inner linearization sensor output of qualification.For example, Figure 40 comprises the typical curve of the output of main magnetometer 3902 and controlled magnetometer 3904 with respect to cylinder position, shows in the linearization that limits the output of cylinder position scope inner sensor.

[0041] Figure 41-67 shows other embodiment according to cylinder position sensor of the present disclosure.Usually, embodiment shown in Figure 41-67 contains one or more sensors of arranging along tube 110, fluxgate sensor for example, with sensing from field that the one or more permanent magnets that for example are connected to piston 114 send.

[0042] for example, Figure 41-42 shows according to embodiment of the present disclosure, its mesopore 4102 is formed in the outside surface of tube, is used to receive the sensing element 920 of tangentially locating with respect to tube, promptly extends perpendicular to tube axis (axis of movement) and crosses at the lip-deep tube of tube width.Although shown in exemplary embodiments show the single hole 4102 that wherein has the single sense element, should be appreciated that hole and sensing element that any amount can be set.In addition, can in a hole, be provided with a plurality of sensing elements and/or along a plurality of directions (for example, tangential, axially, the oblique angle tangential etc.) sensing element is set.In many examples, by in the hole 4102 both sides provide the ferromagnetic flux concentrator with guiding by magnetic flux by sensing element 920, can increase magnetic flux by sensing element.

[0043] Figure 43 shows another exemplary embodiments, wherein arranges sensing element 920-1,920-2,920-3,920-4 along the length location one of tube outer surface.In addition, can use the sensing element 920 of any amount, and with the combination of direction or direction arbitrarily.Equally, the sensing element in the illustrated embodiment is shown as along the length of tube equi-spaced apart each other.But sensing element is equi-spaced apart not also.For example, it is closer that sensing element can need the interval of high-res to get at tube together, farther at interval in the zone that can accept or expect low-res.

[0044] Figure 43 shows another exemplary embodiments, and wherein the first sensing element 920-1 and the second sensing element 920-2 are around the circumference of tube, and for example, apart 180 spend.As among all embodiment here, sensing element output can be made up by different way to eliminate the outfield.The sensing element of any amount can be set along any direction in addition.In addition, can in the array that extends along the length of tube, one group of circumferential sensing element be set.

[0045] when sensing element was arranged in the outside surface of tube 110, they can be exposed to the damage that brings because of external environment.In addition, external magnetic field can influence sensor output, thus the failure position sensing.For the protection sensing element, outer cover is set on sensing element.For example, Figure 45 shows the elongated cover 4502 that is fixed to tube 110 outside surfaces, to keep being arranged in the sensing element on the cover doffing, for example, as shown in Figure 43.Described cover can have necessary arbitrary shape of used sensing element or structure in the protection application.Preferably, described cover can provide mechanical protection, and also the shade sensing element is not influenced by the external magnetic field at least in part.

[0046] as described herein, magnet is connected to piston, bar or nut has set up from magnet by for example closed loop flux path of the magnetic flux of piston, bar and cylinder amount.Be located in this closed-loop path or near the sensor of optional position can be used for the magnetic flux of sensing magnet, to determine cylinder/bar position.Therefore, all structures that are used for magnet is connected to piston or bar described herein all can be used by the sensing element on being arranged in tube.

[0047] Figure 46-47 shows exemplary embodiments, wherein in the hole in being formed at piston 114 around a plurality of discontinuous magnet 908a of the circumference of piston 114.The outer cover 4602 that magnet is fixed on piston 114 ends covers.Circumference around piston provides magnet to can be used for the position transducer output that keeps appropriate in the cylinder structure, wherein needs piston rod freely to rotate.

[0048] Figure 48-51 shows according to exemplary embodiments of the present disclosure, and wherein magnet is only partly around the piston circumferential registration.In the embodiment shown, arcuate socket 4802 is formed in the piston 114, is used to receive magnet assembly 4804.Shown in the exemplary embodiments, magnet assembly comprises the

magnetosphere

4806,4804,4810 of separation.For example, as shown in Figure 51, with respect to layer 4608, shown in the exemplary embodiments every layer all comprise six

magnetic heaps

4812,4814,4816,4818,4820 and 4822, every heap has three magnet 908a.

[0049] magnetosphere can be arranged between first arc 4824 and second arc 4826, and magnet assembly can be installed in the arcuate socket 4802.Assembly 4804 can be connected on the piston by retaining ring 4828, and retaining ring 4828 is installed in the respective grooves of outer surface of piston.Though illustrated embodiment shows the magnet of specific quantity and layout, should be appreciated that the magnet that can in the magnetic heap of any amount, use any amount.

[0050] Figure 52 and 53 comprise respectively for according in the simulation cylinder position sensing system of the present disclosure radially Gauss 5200 and axially Gauss 5300 with respect to the curve map of bar position (stroke), wherein said simulation cylinder position sensing system uses the sensing element that is arranged on tube and the piston, comprises the permanent magnet as shown in Figure 48-51.Show the different curve map of air gap between sensing element and the magnet.As shown in the figure, sensing element provides the output that can be used to determine the cylinder rod position, thereby can determine to connect the position of any moving element thereon.

[0051] but be used for that permanent magnet is connected to piston 114 to come other structure of indicator stem position also be possible to produce sense field.For example, Figure 54-55 shows magnet assembly 4804a, and this assembly comprises the single arc magnet 908 that is arranged between first arc 4824 and second arc 4826.Described assembly can be installed in the hole 4802 in the piston, and is fixed to the upper by retaining ring 4828, and described retaining ring is installed in the respective grooves in the outer surface of piston.Figure 56-57 shows other embodiment, and wherein

toroidal magnet

908g, 908h arrange around the outside surface of piston.Figure 58-59 shows another embodiment, and wherein toroidal magnet 908g can use nut 5802 to be fixed on the piston, and nut 5802 is fixed to piston 11-4 on the bar 112.

[0052] Figure 60 shows fluxgate sensor element 920-1, the 920-2 that is used for from the outside surface of arranging tube 110 in an embodiment ... 920-N obtains the typical electrical component of cylinder position information, and wherein one or more permanent magnets are connected on the piston.Shown in exemplary embodiments comprise fluxgate magnetometer 6002 and the signal processing unit 6004 that is connected to the fluxgate sensor element.Each fluxgate of magnetometer 6002 monitoring, and the corresponding analog signal that the magnetic flux of expression effect separates offered signal processing unit.Signal processing unit can be configured to select specific in the output of magnetometer.

[0053] each output all is sinusoidal substantially at least a portion throw of lever.For example, Figure 61 shows and follows sensor element 920-1,920-2 ... the pure sinusoid signal 6102 that the output 6104 of the magnetometer that the output of 920-N links is compared.As shown in the figure, sensing element provides on a part of throw of lever (extension) and has been close to sinusoidal signal.Signal processing unit 6004 can receive magnetometer output, and can calculate the arc tangent of the sin/cos fluxgate output of selected sensing element, is linear characteristic 6202 so that voltage to be provided substantially with respect to stroke (bar position), as shown in Figure 62.Because discontinuous voltage levvl is associated with bar each position in its stroke/extension, so the output characteristics of the substantial linear of signal processing unit can be used for determining the bar position.

[0054] the multiple structure of sensor electrical component is feasible.Usually, described soft copy can comprise in the following aspect one or multinomial:

Variate on the tangent line field is to provide thin packing;

Normal/radial or pure radially sensing element structure allow variate, to eliminate public and enhancing basis signal;

Can use a plurality of sensing elements that resolution is provided, and correction is taken off partially, bending.For example, can three or four sensing elements be set around bar, with by the phase concentrated on the same group soft copy come average signal;

Diagnosing abnormal magnetic field;

Because the impedance of fluxgate coil sensing element is along with temperature change, so they can be used for temperature sensing;

For example, cut apart the linearization of exporting by using the automatic gain control structure can realize exporting with sensor;

System can use 12V to substitute 5V as input voltage, to increase dynamic range and the resolution of enhancing is provided;

System uses variate to disconnect the influential earth magnetism of countercylinder steel construction;

Axial and tangential magnetic field output is capable of being combined to obtain sinusoidal output;

System can use sine/twill and tangent algorithm to eliminate the magnet aging effect.

[0055] obtains the arc tangent that sinusoidal output can help to calculate sin/cos from sensing element, to obtain linear output.With reference to Figure 63, have been found that with sensing element and compare perpendicular to the tangential sensing element structure of tube axis arranged, sensing element 920 is tangentially directed and can cause improved sinusoidal output with respect to the axis bevel θ of tube with respect to tube 110.In one embodiment, sensing element 920 can be used as different from connecting, and described angle θ can be 45 degree.In one embodiment, the different sensing elements that connect can be along the spaced apart 25mm of the length of tube axis.

[0056] Figure 64-67 shows the performance according to the structure of Figure 63, comprises a pair of sensing element that diverges to miter angle θ.Figure 64 comprises curve 6402 and the pure cosine curve 6404 of sensing element output with respect to bar position/stroke.As shown in the figure, be sinusoidal substantially going up on a large scale of bar position basically with the corresponding output of a pair of sensing element that separates with miter angle θ.Figure 65 comprises from the sine 6502 of a pair of sensing element acquisition that diverges to miter angle θ and the curve of slope 6504 outputs, and the arc tangent curve 6506 of sin/cos.As shown in the figure, described arc tangent is linear substantially on the scope of bar position.Figure 66 comprises and the curve 6600 of the sensing element output with different throw of lever speed with respect to bar position/stroke, show eddy current effects, the derivative that Figure 67 comprises sense field is used for revising the curve 6700 of position of the strong sensing signal of eddy current effects with respect to expression.

[0057] system that comprises the sensor that is located at tube 110 outsides can use with a sensor or a series of sensor (comprising two or more sensors).Compare with spot measurement, a series of sensors of locating along the tube length degree can provide more information.In addition, when using fluxgate sensor, sensor array can concentrate the form of soft copy to use.The terrestrial magnetic field can use variate and tube signal (barrel signature) to manage.Its structure is also scalable to be the random length of cylinder, and can revise by the appropriate location of sensor, with a specific region of sensing cylinder.Appropriate interval scalable by sensor is by the variable resolution degree of throw of poston.In addition, by the sensor sensing can use the sin/cos algorithm to come temperature and aging variation the in the message magnet by the advance rotation field that produces of piston, and allow magnet in different temperature with have lower cost (hydraulic fluid warms and the low variation that can cause magnet temperature of environment temperature).

[0058] in addition, this system can not rely on cylinder structure, material or assemble method, and the long certainly of minimum can be provided, and for example, does not change from long.Make it possible to carry out other diagnosis by the out of Memory of advancing, described system can not be subject to magnet " collision,, influence.Each stroke all can provide the magnetic that overcomes all ox bar magnet problems to eliminate function, uses steel or non-ironwork plug can have appropriate air gap management.In addition, the connector that can use outer cover to protect to come out from sensor, described connector can stretch out from cylinder end; so that wire routing is the shortest; and make to line may damage minimum, can need not to have other coil that is used for " interlocking " translation function, can not adopt hydraulic pressure.

[0059] therefore,, provide a kind of cylinder position sensor, having comprised according to one side of the present disclosure: at least one magnet, it provides magnetic flux in the flux path that extends through piston rod, cylinder barrel and piston; And at least one sensing element, this sensing element is configured to provide output in response to described magnetic flux, described output along with described piston with respect to the position of described cylinder barrel and change.

[0060] according to another aspect of the present disclosure, a kind of cylinder system is provided, comprising: cylinder barrel; Be arranged in the piston in the described cylinder barrel, in order to respect to described cylinder barrel to-and-fro movement; Be connected to the piston rod of described piston, described piston rod is configured to axially move with respect to described tube along with the to-and-fro movement of described cylinder; Be connected at least one magnet of described piston rod; And at least one sensing element, described sensing element is configured to provide output in response to the magnetic flux of described at least one magnet, described output along with described bar with respect to the position of described cylinder barrel and change.

[0061] in accordance with a further aspect of the present invention, provide a kind of cylinder system, having comprised: cylinder barrel; Be arranged in the piston in the described cylinder barrel, in order to respect to described cylinder barrel to-and-fro movement; Be connected to the piston rod of described piston, described piston rod is configured to axially move with respect to described tube along with the to-and-fro movement of described cylinder; Be connected at least one magnet of described piston rod; And at least one sensing element, described sensing element is configured to provide output in response to the magnetic flux of described at least one magnet, described output along with described bar with respect to the position of described cylinder barrel and change.

[0062] embodiment that described of this paper only is some parts of the present invention of utilizing, and describes by limiting examples here.The feature of all embodiment described herein or aspect can be combined with any further feature or the aspect of other embodiment arbitrarily described herein, meet system of the present disclosure to provide.Obviously, do not break away from itself under the situation of the spirit and scope of the invention, many other embodiment are apparent to one skilled in the art.

Claims

1. cylinder system comprises:

Cylinder barrel;

Be arranged in the piston in the described cylinder barrel, in order to respect to described cylinder barrel to-and-fro movement;

Be connected to the piston rod of described piston, described piston rod is configured to axially move with respect to described tube along with the described to-and-fro movement of described cylinder;

Directly be connected at least one magnet of described piston rod; And

At least one sensing element, described sensing element are configured to provide in response to the magnetic flux of described at least one magnet output, described output along with described bar with respect to the position of described cylinder barrel and change.

2. according to the system of claim 1, wherein said at least one sensing element be positioned at described tube outside surface near.

3. according to the system of claim 2, wherein said tube is formed from steel.

4. according to the system of claim 2, described system also comprises be connected to the outer cover that described tube is gone up and extended on described at least one sensing element, and described cover structure becomes at least in part that described at least one sensing element of shade is not subjected to the influence of external magnetic field.

5. according to the system of claim 1, described system comprises a plurality of described sensing elements, near described a plurality of sensing elements are positioned at its outside surface in the mode of array along the length of described tube.

6. according to the system of claim 1, described system also comprises the bar guide of the end that is connected to described tube, at least a portion of wherein said bar is extended from described bar guide, and wherein said at least one sensing element is arranged in the described bar guide adjacent with described bar at least in part.

7. according to the system of claim 6, wherein said bar guide is formed from steel.

8. according to the system of claim 1, described system comprises first and second in the described sensing element, and it connects in order to differential output to be provided.

9. system according to Claim 8 is near described first and second outside surfaces that are positioned at described tube in the wherein said sensing element.

10. according to the system of claim 9, in the wherein said sensing element described first and second with respect to the mode of tube axis bevel and tangentially directed with respect to described tube.

11. according to the system of claim 1, wherein said at least one sensing element comprises fluxgate sensor.

12. according to the system of claim 1, described system also comprises near at least one the degaussing body that is arranged in the described bar, described degaussing body structure becomes to reduce the residual magnetic field that causes because of the external magnetic field in the described bar.

13. according to the system of claim 1, described system also comprises the degaussing coil of arranging around described bar, described coil structure becomes the excitation by the cyclical signal of described coil to reduce the residual magnetic field that is caused by the external magnetic field in the described bar.

14. a cylinder system comprises:

Cylinder barrel;

Be connected at least one magnet of described piston rod; And

15. according to the system of claim 14, wherein said at least one sensing element is positioned near the outside surface of described tube.

16. according to the system of claim 15, wherein said tube is formed from steel.

17. according to the system of claim 15, described system also comprises be connected to the outer cover that described tube is gone up and extended on described at least one sensing element, described cover structure becomes at least in part that described at least one sensing element of shade is not subjected to the influence of external magnetic field.

18. according to the system of claim 14, described system comprises a plurality of described sensing elements, near described a plurality of sensing elements are positioned at its outside surface in the mode of array along the length of described tube.

19. system according to claim 14, described system also comprises the bar guide of the end that is connected to described tube, at least a portion of wherein said bar is extended from described bar guide, and wherein said at least one sensing element is arranged in the described bar guide adjacent with described bar at least in part.

20. according to the system of claim 19, wherein said bar guide is formed from steel.

21. according to the system of claim 14, described system comprises first and second in the described sensing element, it connects in order to differential output to be provided.

22. according to the system of claim 21, near described first and second outside surfaces that are positioned at described tube in the wherein said sensing element.

23. according to the system of claim 22, in the wherein said sensing element described first and second with respect to the mode of tube axis bevel and tangentially directed with respect to described tube.

24. according to the system of claim 14, wherein said at least one sensing element comprises fluxgate sensor.

25. according to the system of claim 14, described system also comprises near at least one the degaussing body that is arranged in the described bar, described degaussing body structure becomes to reduce the residual magnetic field that causes because of the external magnetic field in the described bar.

26. according to the system of claim 14, described system also comprises the degaussing coil of arranging around described bar, described coil structure becomes the excitation by the cyclical signal of described coil to reduce the residual magnetic field that is caused by the external magnetic field in the described bar.

27. according to the system of claim 14, wherein said at least one magnet is arranged in the described bar at least in part.

28. according to the system of claim 14, wherein said at least one magnet is arranged in the described piston at least in part.

29. according to the system of claim 14, wherein said at least one magnet is arranged in the nut that is used for described piston is connected to described piston rod at least in part.

30. a cylinder position sensor comprises:

At least one magnet, it provides magnetic flux in the flux path that extends through piston rod, cylinder barrel and piston; And

At least one sensing element, this sensing element are configured to provide output in response to described magnetic flux, described output along with described piston with respect to the position of described cylinder barrel and change.

31. according to the system of claim 30, wherein said at least one sensing element is positioned near the outside surface of described tube.

32. according to the system of claim 31, described system comprises a plurality of described sensing elements, near described a plurality of sensing elements are positioned at its outside surface in the mode of array along the length of described tube.

33. system according to claim 30, described system also comprises the bar guide of the end that is connected to described tube, at least a portion of wherein said bar is extended from described bar guide, and described flux path extends through described bar guide, and wherein said at least one sensing element is arranged in the described bar guide adjacent with described bar at least in part.

34. according to the system of claim 30, described system comprises first and second in the described sensing element, it connects in order to differential output to be provided.

35. according to the system of claim 34, near described first and second outside surfaces that are positioned at described tube in the wherein said sensing element.

36. according to the system of claim 35, in the wherein said sensing element described first and second with respect to the mode of tube axis bevel and tangentially directed with respect to described tube.

37. according to the system of claim 30, wherein said at least one sensing element comprises fluxgate sensor.

38. according to the system of claim 30, wherein said at least one magnet is arranged in the described bar at least in part.

39. according to the system of claim 30, wherein said at least one magnet is arranged in the described piston at least in part.

40. according to the system of claim 30, wherein said at least one magnet is arranged in the nut that is used for described piston is connected to described piston rod at least in part.