CN115163608B - Hydraulic cylinder integrated with variable magnetic flux type speed sensor - Google Patents

Hydraulic cylinder integrated with variable magnetic flux type speed sensor Download PDF

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Publication number
CN115163608B
CN115163608B CN202210810051.5A CN202210810051A CN115163608B CN 115163608 B CN115163608 B CN 115163608B CN 202210810051 A CN202210810051 A CN 202210810051A CN 115163608 B CN115163608 B CN 115163608B
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piston
permanent magnet
hydraulic cylinder
piston shaft
end cover
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CN115163608A (en
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丁川
夏宁
周维华
朱宽宽
朱海鑫
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Zhejiang University of Technology ZJUT
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Zhejiang University of Technology ZJUT
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/20—Other details, e.g. assembly with regulating devices
    • F15B15/28—Means for indicating the position, e.g. end of stroke
    • F15B15/2815—Position sensing, i.e. means for continuous measurement of position, e.g. LVDT
    • F15B15/2861—Position sensing, i.e. means for continuous measurement of position, e.g. LVDT using magnetic means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B19/00—Testing; Calibrating; Fault detection or monitoring; Simulation or modelling of fluid-pressure systems or apparatus not otherwise provided for
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/003—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring position, not involving coordinate determination
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
    • G01P3/42—Devices characterised by the use of electric or magnetic means
    • G01P3/50—Devices characterised by the use of electric or magnetic means for measuring linear speed

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
  • Actuator (AREA)

Abstract

The invention discloses a hydraulic cylinder integrated with a variable magnetic flux type speed sensor, which comprises a cylinder body, wherein two ends of the cylinder body along the axial direction respectively enclose a magnetic induction space with a first end cover and a second end cover; the piston assembly is arranged in the magnetic induction space and comprises a piston shaft axially arranged in the cylinder body and a piston slidably sleeved on the piston shaft; the magnetic induction mechanism is arranged in the magnetic induction space and comprises a permanent magnet for forming a magnetic field around the piston shaft and a coil for inducing induced electromotive force of the changed magnetic field; when the piston slides on the piston rod, the size of magnetic flux in the magnetic induction space can be changed, and the coil correspondingly acquires the induced electromotive force of the magnetic field and outputs the induced electromotive force to the outside of the cylinder body, so that the moving speed of the piston is acquired. The invention solves the technical problems of huge hydraulic cylinder volume, low integration level and poor connection of wires caused by the fact that a sensor of the hydraulic cylinder is arranged in the cylinder body and a moving part of the sensor is fixed on a piston to move synchronously with the piston in the prior art.

Description

Hydraulic cylinder integrated with variable magnetic flux type speed sensor
Technical Field
The invention relates to the technical field of hydraulic cylinders, in particular to a hydraulic cylinder integrated with a variable magnetic flux type speed sensor.
Background
The hydraulic cylinder is a hydraulic executive component which converts hydraulic energy into mechanical energy and does linear reciprocating motion or swinging motion, and has simple structure and reliable work. When the reciprocating motion is realized by using the hydraulic system, a speed reducing device can be omitted, and the hydraulic system has no transmission clearance and stable motion, so that the hydraulic system is widely applied to various hydraulic systems.
The hydraulic cylinder may be provided with a speed sensor and/or a position sensor to obtain the speed and/or position of the moving part. The speed sensor is a sensor capable of measuring the running speed of the object to be measured and converting the running speed into an output signal, and the position sensor is a sensor capable of sensing the position of the object to be measured and converting the position into an output signal.
In order to ensure the working performance of the hydraulic cylinder, the sensor is generally arranged outside the cylinder body of the hydraulic cylinder, but the anti-interference capability and the anti-pollution capability of the sensor are influenced, and the overall size is larger and the integration level is lower. For this reason, the related art designs the sensor inside the hydraulic cylinder, which can effectively avoid the above problems, but it fixes the moving part of the sensor on the piston to move synchronously with the piston, and the magnetic induction part is fixed inside the cylinder body to induce the speed and position of the piston. The design is limited by the structure of the magnetic induction part, when a longer piston stroke is needed, the whole volume of the hydraulic cylinder is huge, the integration level is low, and meanwhile, poor connection contact between the magnetic induction part and the moving part of the sensor is easy to cause.
Therefore, the above prior art has at least the following technical problems: in the prior art, a sensor of a hydraulic cylinder is arranged in the cylinder body, and a moving part of the sensor is fixed on a piston to move synchronously with the piston, so that the hydraulic cylinder body is huge in volume, low in integration level and easy to contact poorly in wiring.
Disclosure of Invention
According to the hydraulic cylinder integrating the variable magnetic flux type speed sensor, the technical problems that in the prior art, the sensor of the hydraulic cylinder is built in the cylinder body, the moving part of the sensor is fixed on the piston to move synchronously with the piston, the hydraulic cylinder is large in volume, the integration level is low, and poor contact is caused easily in wiring are solved.
To solve the above technical problems, an embodiment of the present invention provides a hydraulic cylinder integrated with a variable magnetic flux type speed sensor, including:
the magnetic induction device comprises a cylinder body, wherein a first end cover and a second end cover are respectively arranged at two ends of the cylinder body along the axial direction, and a magnetic induction space is enclosed by the cylinder body, the first end cover and the second end cover;
the piston assembly is arranged in the magnetic induction space and comprises a piston shaft arranged in the cylinder body and axially arranged along the cylinder body and a piston which is slidably and coaxially sleeved on the piston shaft;
the magnetic induction mechanism is arranged in the magnetic induction space and comprises a permanent magnet used for forming a magnetic field around the piston shaft and a coil uniformly wound on the piston shaft and used for inducing the electromotive force of the magnetic field;
when the piston axially slides on the piston shaft along the piston shaft, the size of magnetic flux in the magnetic induction space can be changed, and the coil correspondingly acquires the induced electromotive force of the magnetic field and outputs the induced electromotive force to the outside of the cylinder body, so that the moving speed of the piston is acquired based on the induced electromotive force.
Further, the permanent magnets comprise a first permanent magnet and a second permanent magnet, wherein the first permanent magnet is arranged on the inner surface of the first end cover, the second permanent magnet is arranged on the inner surface of the second end cover, and the magnetic pole directions of the first permanent magnet and the second permanent magnet are opposite.
Further, one ends of the first permanent magnet and the second permanent magnet, which face the cylinder body, are both S poles, and one ends of the first permanent magnet and the second permanent magnet, which face the cylinder body, are both N poles.
Further, a first notch is formed in the inner surface of the first end cover in a recessed mode, a second notch is formed in the inner surface of the second end cover in a recessed mode, the first permanent magnet is fixedly arranged in the first notch, and the second permanent magnet is fixedly arranged in the second notch; and the outer surface of the first permanent magnet is flush with the inner surface of the first end cover, and the outer surface of the second permanent magnet is flush with the inner surface of the second end cover.
Further, the two axial ends of the piston shaft are respectively aligned with the first permanent magnet and the second permanent magnet, so that a magnetic field is formed around the piston shaft, and when the piston slides on the piston shaft, the magnetic flux in the cylinder body is changed;
further, a positioning sleeve is arranged outside the coil, the positioning sleeve and the piston shaft are coaxially arranged, the two ends of the positioning sleeve along the axial direction of the piston shaft extend to the first end cover and the second end cover respectively, and the piston is slidably arranged outside the positioning sleeve.
Further, a linear hall element for measuring a magnetic induction value is further arranged on the piston shaft, and the position of the piston on the piston shaft 13 is obtained based on the magnetic induction value.
Further, the piston shaft is provided with three linear Hall elements at intervals along the axial direction thereof.
Further, a first sealing ring is arranged between the cylinder body and the first end cover, and a second sealing ring is arranged between the cylinder body and the second end cover.
Further, the hydraulic cylinder further comprises a controller, wherein the controller is respectively connected with the coil and the linear Hall element and is used for receiving the induced electromotive force acquired by the coil and the magnetic induction intensity acquired by the linear Hall element; the controller obtains the moving speed of the piston according to the obtained induced electromotive force, and obtains the position of the piston on the piston shaft according to the linear Hall element.
One or more technical solutions provided in the embodiments of the present application at least have the following technical effects or advantages:
(1) The permanent magnet forming the magnetic field and the coil uniformly wound on the piston shaft for inducing the electromotive force of the magnetic field are arranged around the piston shaft, when the piston axially slides on the piston shaft along the piston shaft, the size of the magnetic flux in the magnetic induction space can be changed, the coil correspondingly acquires the induced electromotive force of the magnetic field and outputs the induced electromotive force to the outside of the cylinder body, so that the moving speed of the piston can be acquired based on the induced electromotive force,.
(2) Through setting up the linear hall element that is used for measuring magnetic induction intensity value on the piston axle, can acquire the piston based on magnetic induction intensity value in the epaxial position of piston has further realized position sensor's function, is equivalent to integrating speed, position sensor in the pneumatic cylinder, compares in directly setting up position sensor, and the structure is simpler, has increased the integrated level of pneumatic cylinder.
(3) Because the Hall element is built in the hydraulic cylinder and is not fixed with the piston on the hydraulic cylinder, namely the displacement sensor can not move synchronously along with the moving part in the hydraulic cylinder, and meanwhile, the Hall element can not limit the moving stroke of the piston, therefore, when the piston moves, the internal wiring can not be disturbed, and compared with the prior art, when the piston has the same moving stroke, the whole volume of the hydraulic cylinder is smaller, the integration level is higher, the problem that the sensor of the hydraulic cylinder is built in the cylinder in the prior art, the moving part of the sensor is fixed on the piston and moves synchronously with the piston, so that the hydraulic cylinder is large in volume, the integration level is low, and the wiring is easy to contact poorly is solved, and the beneficial effects of small volume, simple structure, high integration level, high effectiveness of the position sensor and capability of effectively avoiding being disturbed or polluted are realized.
(4) The moving speed of the piston is in direct proportion to the output voltage of the coil, the error of the speed sensor depends on the error of voltage reading, and the accuracy of speed measurement is high.
(5) The linearity of the magnetic induction intensity measured by the three linear Hall elements along with the change of the position of the piston is good, so that the measured position error is small.
(6) The coil is provided with two layers to increase the induced electromotive force, thereby making the movement speed measurement of the piston 4 more accurate.
(7) The piston passes through the locating sleeve setting outside the coil, and the locating sleeve can protect the coil effectively, prevents piston wearing and tearing coil.
(8) The hydraulic cylinder integrated with the variable magnetic flux type speed and position sensor can improve the measurement accuracy and the service life of the sensor; meanwhile, the controller is arranged, so that the test data can be well output and visually read.
Drawings
FIG. 1 is a schematic view of an overall cross-sectional structure of a hydraulic cylinder integrated with a variable magnetic flux type speed sensor according to an embodiment of the present application;
FIG. 2 is a schematic diagram of an overall cross-sectional structure of a hydraulic cylinder with an integrated variable magnetic flux type speed sensor according to an embodiment of the present application when a piston of the hydraulic cylinder moves to a certain position;
FIG. 3 is a simulation diagram of the distribution of magnetic induction lines on one side of a hydraulic cylinder integrated with a variable magnetic flux type speed sensor according to an embodiment of the present application;
FIG. 4 is a simulation diagram of a single-sided magnetic induction line distribution when a piston of a hydraulic cylinder integrated with a variable magnetic flux type speed sensor moves to a certain position according to an embodiment of the present application;
FIG. 5 is a schematic diagram of a relationship between a piston movement speed and a coil output voltage of a hydraulic cylinder with an integrated variable magnetic flux speed sensor according to an embodiment of the present application;
FIG. 6 is a schematic diagram of the relationship between magnetic induction and piston displacement measured by a second linear Hall element of a hydraulic cylinder integrated with a variable magnetic flux type speed sensor according to an embodiment of the present application;
FIG. 7 is a schematic diagram of the relationship between magnetic induction and piston displacement measured by a first linear Hall element of a hydraulic cylinder integrated with a variable magnetic flux type speed sensor according to an embodiment of the present application;
fig. 8 is a schematic diagram of a relationship between magnetic induction intensity and piston displacement measured by a third linear hall element of a hydraulic cylinder integrated with a variable magnetic flux type speed sensor according to an embodiment of the present application.
In the figure: 1. a first end cap; 2. a first permanent magnet; 3. a cylinder; 4. a piston; 5. a coil; 6. a second seal ring; 7. a second end cap; 8. a second permanent magnet; 9. a positioning sleeve; 10. a third linear hall element; 11. a second linear hall element; 12. a first linear hall element; 13. a piston shaft; 14. a first seal ring.
Detailed Description
According to the hydraulic cylinder integrating the variable magnetic flux type speed sensor, the technical problems that in the prior art, the sensor of the hydraulic cylinder is built in the cylinder body, the moving part of the sensor is fixed on the piston to move synchronously with the piston, the hydraulic cylinder is large in volume, the integration level is low, and poor contact is caused easily in wiring are solved.
In order to solve the technical problems, the technical scheme provided by the application has the following overall thought:
a permanent magnet forming a magnetic field and a coil uniformly wound on the piston shaft for inducing electromotive force of the magnetic field are disposed around the piston shaft, and when the piston slides on the piston shaft in the axial direction of the piston shaft, the size of magnetic flux in the magnetic induction space can be changed, the coil correspondingly acquires the induced electromotive force of the magnetic field and outputs the induced electromotive force to the outside of the cylinder body, so that the moving speed of the piston can be acquired based on the induced electromotive force, and the function of the speed sensor is realized;
in addition, a linear Hall element for measuring the magnetic induction intensity value is arranged on the piston shaft, so that the position of the piston on the piston shaft can be obtained based on the magnetic induction intensity value, and the function of a position sensor is further realized;
therefore, by providing the coil, the permanent magnet, the hall element, it is equivalent to providing the speed sensor and the position sensor; meanwhile, as the coil, the permanent magnet and the Hall element are all arranged in the hydraulic cylinder, the permanent magnet is fixed at two ends of the piston rod, and the coil and the Hall element are arranged on the piston rod and are not fixed with the piston on the hydraulic cylinder, namely, the speed sensor and the displacement sensor can not synchronously move along with the moving parts in the hydraulic cylinder; meanwhile, the sensor is not limited to the movement stroke of the piston, so that the internal wiring is not disturbed when the piston moves, and compared with the prior art, the hydraulic cylinder has smaller whole volume and higher integration level when the sensor has the same movement stroke;
in sum, the sensor of the pneumatic cylinder among the prior art has effectively been solved to this application embodiment is built-in the cylinder body, and the motion part of sensor is fixed on the piston and is moved with the piston synchronization, leads to the hydraulic cylinder volume huge, the low and technical problem that the wiring is easy to contact poorly of integrated level, has realized small, simple structure, integrated level height, the sensor validity is high, can effectively avoid by interference or contaminated beneficial effect.
The following detailed description of the technical solutions of the present application will be made with reference to the accompanying drawings and specific embodiments, and it should be understood that the specific features of the embodiments and embodiments of the present application are detailed descriptions of the technical solutions of the present application, and not limiting the technical solutions of the present application, and the technical features of the embodiments and embodiments of the present application may be combined with each other without conflict.
Example 1
Referring to fig. 1 and 2, embodiment 1 of the present invention proposes a hydraulic cylinder integrated with a variable magnetic flux type speed sensor, so as to solve the above-mentioned technical problems in the prior art.
Fig. 1 is a schematic diagram of the overall structure of a hydraulic cylinder integrated with a variable magnetic flux type speed sensor according to an embodiment of the present invention, and fig. 2 is a schematic diagram of the overall structure of the piston 4 in fig. 1 when it moves to a certain position. As shown in fig. 1 and 2, the embodiment of the invention discloses a hydraulic cylinder integrated with a variable magnetic flux type speed sensor, which is used for detecting the speed of a piston 4 when moving inside a cylinder body 3, and comprises the cylinder body 3, a piston assembly and a magnetic induction mechanism. The two ends of the cylinder body 3 along the axial direction are respectively provided with a first end cover 1 and a second end cover 7, and the connection mode of the cylinder body 3 and the end covers can be a thread, a bolt or a buckle connection mode; and the cylinder body 3 encloses a closed magnetic induction space with the first end cover 1 and the second end cover 7. The piston assembly is arranged in the magnetic induction space and comprises a piston shaft 13 arranged in the cylinder body 3 and axially arranged along the cylinder body 3 and a piston 4 slidably and coaxially sleeved on the piston shaft 13. The magnetic induction mechanism is provided in the magnetic induction space, and includes a permanent magnet for forming a magnetic field around the piston shaft 13 and a coil 5 uniformly wound on the piston shaft 13 for inducing an electromotive force of the magnetic field. When the piston 4 slides on the piston shaft 13 along the axial direction of the piston shaft 13, the magnitude of the magnetic flux in the magnetic induction space can be changed, and the coil 5 correspondingly acquires the induced electromotive force of the magnetic field and outputs the induced electromotive force to the outside of the cylinder 3, so that the moving speed of the piston 4 is acquired based on the induced electromotive force.
The variable magnetic flux type speed sensor is integrated in the hydraulic cylinder, so that the integration level of the hydraulic cylinder can be increased, and the sensor is not easy to interfere or pollute in the working process.
According to the invention, the permanent magnet forming the magnetic field and the coil 5 uniformly wound on the piston shaft 13 for inducing the electromotive force of the magnetic field are arranged around the piston shaft 13, when the piston 4 slides axially on the piston shaft 13 along the piston shaft 13, the magnitude of the magnetic flux in the magnetic induction space can be changed, the coil correspondingly acquires the induced electromotive force of the magnetic field and outputs the induced electromotive force to the outside of the cylinder body 3, so that the moving speed of the piston 4 can be acquired based on the induced electromotive force, the function of the speed sensor is realized, and the coil and the permanent magnet are not fixed with a moving part (piston) on the hydraulic cylinder, namely, the speed sensor does not synchronously move along with the moving part in the hydraulic cylinder, and meanwhile, the speed sensor is not limited to the moving stroke of the piston, so that the internal wiring is not disturbed, and compared with the prior art, the sensor with the same moving stroke, the whole volume of the hydraulic cylinder is smaller, the integration degree is higher, the sensor of the hydraulic cylinder is fixed in the cylinder body, the piston synchronously moves, the hydraulic cylinder is huge, the integration degree is low, and the wiring is easy to contact with the moving part, the sensor is easy, the technical problem of the volume is simple, the structure is easy, the sensor is high, the effect is effectively avoided, and the pollution is avoided, or the effect is effectively avoided.
The coil 5 may be connected to a controller outside the cylinder 3, which automatically calculates and displays the moving speed of the piston 4 based on the output voltage corresponding to the induced electromotive force of the coil 5. Referring to fig. 3 and 4, taking the example that the piston 4 moves from bottom to top, the distribution of magnetic induction lines inside the cylinder 3 will change significantly during the process that the piston 4 moves from one end to the other end, and then the magnitude of magnetic flux inside the cylinder 3 will change, and as known from the general formula of electromagnetic induction law, induced electromotive force will be generated on the coil 5 on the piston shaft 13 during the process that the piston 4 moves. When the number of turns of the coil 5 is unchanged, the moving speed of the piston 4 is in direct proportion to the output voltage of the coil 5, the moving speed and the output voltage are in linear relation, when the speed of the piston 4 is increased, the output voltage of the coil 5 is also increased linearly, and the simulation result is shown in fig. 5.
The controller establishes a corresponding relation between the output voltage of the coil 5 and the moving speed of the piston 4 by comparing the obtained output voltage of the coil 5 with the moving speed of the piston 4, the subsequent coil 5 transmits the output voltage to the controller, and the controller can obtain the moving speed of the piston 4 at the moment according to the output voltage. In addition, the controller may be, but is not limited to, various measuring instruments, acquisition cards, personal computers, notebook computers, smart phones, tablet computers, and the like. But this is not within the scope of the embodiments claimed herein and will not be described in detail.
In addition, it is emphasized that the piston movement speed is proportional to the output voltage of the coil, and the speed sensor error depends on the error of the voltage reading, which makes the speed sensor in this embodiment very high in speed measurement accuracy.
As one of the preferred modes of embodiment 1 of the present invention, the coil 5 is provided with two layers, and it is understood that the provision of two layers of the coil 5 can increase the magnitude of the induced electromotive force, so that the movement speed measurement of the piston 4 is more accurate, but the number of layers of the coil 5 can be set according to the actual situation, and is not limited herein.
Preferably, the permanent magnets comprise a first permanent magnet 2 and a second permanent magnet 8, wherein the first permanent magnet 2 is arranged on the inner surface of the first end cover 1, the second permanent magnet 8 is arranged on the inner surface of the second end cover 7, and the magnetic pole directions of the first permanent magnet 2 and the second permanent magnet 8 are opposite; specifically, the ends of the first permanent magnet 2 and the second permanent magnet 8 facing the interior of the cylinder 3 are both S poles, and the ends of the first permanent magnet 2 and the second permanent magnet 8 facing the exterior of the cylinder 3 are both N poles. It will be appreciated that the magnetic pole directions of the first permanent magnet 2 and the second permanent magnet 8 are set to be opposite, so that a magnetic field is generated in the cylinder 3, and in other embodiments, the ends of the first permanent magnet 2 and the second permanent magnet 8 facing the outside of the cylinder 3 may be set to be S poles, and the ends of the first permanent magnet 2 and the second permanent magnet 8 facing the inside of the cylinder 3 are both set to be N poles.
Specifically, a first notch is formed in the inner surface of the first end cover 1 in a recessed manner, a second notch is formed in the inner surface of the second end cover 7 in a recessed manner, the first permanent magnet 2 is fixedly arranged in the first notch, the second permanent magnet 8 is fixedly arranged in the second notch, and the first notch and the second notch can be square or circular grooves specifically so as to be convenient for arranging the first permanent magnet 2 and the second permanent magnet 8; and the outer surface of the first permanent magnet 2 is flush with the inner surface of the first end cover 1, the outer surface of the second permanent magnet 8 is flush with the inner surface of the second end cover 7, it is understood that the inner surface of the first end cover 1 is not the concave bottom surface of the first notch, and the inner surface of the second end cover 7 is not the concave bottom surface of the second notch, that is, the first permanent magnet 2 and the second permanent magnet 8 are completely embedded into the first notch and the second notch respectively, so that the two axial end surfaces of the piston shaft 13 are flush with the two inner surfaces of the cylinder 3, and thus when the piston 4 can move more stably inside the cylinder, the piston shaft is not blocked.
In addition, the cross section of the piston 4 at both sides of the piston shaft 13 is in an I shape, and the piston 4 can be driven by external driving force to perform relative sliding movement along the piston shaft 13 in the cylinder 3. The axial ends of the piston shaft 13 are aligned with the first permanent magnet 2 and the second permanent magnet 8, respectively, so that a magnetic field is formed around the piston shaft 13, and the magnitude of the magnetic flux in the cylinder 3 is changed as the piston 4 slides on the piston shaft 13.
Preferably, a positioning sleeve 9 is arranged outside the coil 5, the positioning sleeve 9 is coaxially arranged with the piston shaft 13, two ends of the positioning sleeve 9 along the axial direction of the piston shaft 13 extend to the first end cover 1 and the second end cover 7 respectively, and the piston 4 is slidably arranged outside the positioning sleeve 9; when the piston 4 slides outside the positioning sleeve 9, the positioning sleeve 9 can effectively protect the coil 5 and prevent the piston 4 from wearing the coil 5, and in particular, the positioning sleeve 9 can be a copper ring or a ring body made of other metal materials.
Preferably, the piston shaft 13 is further provided with a linear hall element for measuring the magnetic induction value, so as to obtain the position of the piston 4 on the piston shaft 13 based on the magnetic induction value; the piston shaft 13 is provided with three linear hall elements at equal intervals in the axial direction thereof, and is provided with a first linear hall element 12, a second linear hall element 11, and a third linear hall element 10, which are provided in this order from one end to the other end.
In particular, the hall element is a hall effect based magnetic sensor with which a magnetic field and its changes can be detected and used in various applications related to magnetic fields. Hall elements have many advantages, including their firm structure, small volume, light weight, long life, convenient installation, low power consumption, high frequency, shock resistance, and resistance to contamination or corrosion by dust, oil, moisture, salt mist, etc. The Hall elements are regularly arranged on the object according to the preset positions, when the permanent magnet arranged on the moving object passes through the Hall elements, pulse signals can be measured from the measuring circuit, and the magnetic induction intensity can be measured according to the pulse signal sequence.
The first linear hall element 12, the second linear hall element 11 and the third linear hall element 10 are all connected with a controller outside the cylinder 3, and the controller can acquire and display the position information of the piston 4 according to the magnetic induction intensities sent by the first linear hall element 12, the second linear hall element 11 and the third linear hall element 10. The change of the magnetic induction intensity sensed by the linear Hall element is compared with the position of the piston 4, and the corresponding relation between the change of the magnetic induction intensity and the position of the piston 4 is established by combining algorithms such as scientific comparison of the change quantity and the change amplitude of the comparison data and the like by combining the change speed of the magnetic induction intensity. The subsequent linear Hall element transmits data to the controller, and the controller can acquire the position of the piston 4 at the moment according to the change of the magnetic induction intensity.
Taking the example of the piston 4 moving from bottom to top in fig. 1 and fig. 2, the relationship between the magnetic induction intensity measured by the three linear hall elements and the displacement of the piston 4 in the process of moving the piston 4 from one end to the other end is shown in fig. 6 to fig. 8.
When the piston 4 is at any position, the position of the piston 4 can be obtained by measuring the magnetic induction intensity of three linear Hall elements and substituting the values into a curve obtained by fitting.
When the piston 4 is at the position shown in fig. 4, the magnetic induction intensities measured by the three linear hall elements are obtained respectively, as shown in fig. 6 to 8.
Assuming that the magnetic induction intensity measured by the first linear hall element 12 is greater than 850mTesla and the magnetic induction intensity measured by the third linear hall element 10 is less than 900mTesla, the piston displacement at the moment can be judged to be within the interval of 0-80 mm, and the piston displacement can be fitted with the fitting curve 1 of fig. 6 to obtain an accurate piston 4 displacement value; assuming that the magnetic induction intensity measured by the third linear hall element 10 is greater than 857mTesla and the magnetic induction intensity measured by the first linear hall element 12 is less than 932mTesla, it can be determined that the displacement of the piston 4 is within the range of 80-160 mm, and an accurate displacement value of the piston 4 can be obtained by fitting the displacement value with the fitting curve 2 of fig. 6.
According to the embodiment of the invention, the linear Hall element for measuring the magnetic induction intensity value is arranged on the piston shaft, so that the position of the piston on the piston shaft can be obtained based on the magnetic induction intensity value, the function of the position sensor is further realized, the speed and position sensor is equivalent to being integrated in the hydraulic cylinder, and the integration level of the hydraulic cylinder is increased.
Because the Hall element is arranged in the hydraulic cylinder and is not fixed with a moving part (piston) on the hydraulic cylinder, namely the displacement sensor cannot synchronously move along with the moving part in the hydraulic cylinder, and meanwhile, the Hall element cannot limit the moving stroke of the piston, therefore, when the piston moves, the internal wiring cannot be interfered, and compared with the prior art, when the Hall element has the same moving stroke, the whole volume of the hydraulic cylinder is smaller and the integration level is higher, the problem that the sensor of the hydraulic cylinder is arranged in the cylinder in the prior art, and the moving part of the sensor is fixed on the piston to synchronously move with the piston, so that the hydraulic cylinder is huge in volume, low in integration level and poor in wiring contact easily is solved, and the beneficial effects of small volume, simple structure, high integration level, high effectiveness of the position sensor and capability of effectively avoiding interference or pollution are realized. As a preferred mode of embodiment 1 of the present invention, a first sealing ring 14 is disposed between the cylinder 3 and the first end cover 1, and a second sealing ring 6 is disposed between the cylinder 3 and the second end cover 7, it can be understood that the sealing ring is disposed between the cylinder 3 and the end cover, so that the sealing performance of the hydraulic cylinder is effectively enhanced, and the interference of the piston 4 in the cylinder 3 in the movement process by the outside is avoided.
Example 2
The embodiment 2 of the invention provides a hydraulic cylinder integrated with a variable magnetic flux type speed sensor, which comprises the hydraulic cylinder in the embodiment 1 and a controller arranged outside the hydraulic cylinder, wherein the controller is respectively connected with a coil 5 and a linear Hall element and is used for receiving the induced electromotive force acquired by the coil 5 and the magnetic induction intensity acquired by the linear Hall element; the controller acquires the moving speed of the piston 4 from the acquired induced electromotive force, and acquires the position of the piston 4 on the piston shaft 13 from the linear hall element.
The hydraulic cylinder of this embodiment has become magnetic flow formula speed sensor and position sensor integrated, and the measurement accuracy of sensor is higher, life is longer, and can be with the good output of test data to carry out visual reading.
It will be understood that, although the terms "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments.
The terms of orientation such as external, intermediate, internal, etc. mentioned or possible to be mentioned in this specification are defined with respect to the configurations shown in the drawings, which are relative concepts, and thus may be changed accordingly depending on the different positions and different states of use in which they are located. These and other directional terms should not be construed as limiting terms.
While the invention has been described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes, modifications and additions may be made without departing from the scope of the invention. Equivalent embodiments of the present application are well known to those skilled in the art to which the present invention pertains, when made with the aid of the teachings disclosed herein; meanwhile, any equivalent changes, modifications and evolution of the above embodiments according to the essential technology of the present application still fall within the scope of the technical solution of the present application.

Claims (9)

1. A hydraulic cylinder incorporating a variable magnetic flux type speed sensor, the hydraulic cylinder comprising:
the magnetic induction device comprises a cylinder body (3), wherein a first end cover (1) and a second end cover (7) are respectively arranged at two ends of the cylinder body (3) along the axial direction, and the cylinder body (3) encloses a closed magnetic induction space with the first end cover (1) and the second end cover (7);
the piston assembly is arranged in the magnetic induction space and comprises a piston shaft (13) axially arranged in the cylinder body (3) along the cylinder body (3) and a piston (4) slidably and coaxially sleeved on the piston shaft (13);
a magnetic induction mechanism disposed in the magnetic induction space, and including a permanent magnet for forming a magnetic field around the piston shaft (13) and a coil (5) uniformly wound on the piston shaft (13) for inducing an electromotive force of the magnetic field;
when the piston (4) slides on the piston shaft (13) along the axial direction of the piston shaft (13), the size of magnetic flux in the magnetic induction space can be changed, and the coil correspondingly acquires the induced electromotive force of the magnetic field and outputs the induced electromotive force to the outside of the cylinder body (3), so that the moving speed of the piston (4) is acquired based on the induced electromotive force;
the permanent magnets comprise a first permanent magnet (2) and a second permanent magnet (8), wherein the first permanent magnet (2) is arranged on the inner surface of the first end cover (1), the second permanent magnet (8) is arranged on the inner surface of the second end cover (7), and the magnetic pole directions of the first permanent magnet (2) and the second permanent magnet (8) are opposite.
2. The hydraulic cylinder integrated with the variable magnetic flux type speed sensor according to claim 1, wherein one end of the first permanent magnet (2) and one end of the second permanent magnet (8) facing the cylinder body (3) are both of an S pole, and one end of the first permanent magnet (2) and one end of the second permanent magnet (8) facing the outside of the cylinder body (3) are both of an N pole.
3. A hydraulic cylinder integrated with a variable magnetic flux type speed sensor according to claim 1, characterized in that a first notch is concavely formed on the inner surface of the first end cover (1), a second notch is concavely formed on the inner surface of the second end cover (7), the first permanent magnet (2) is fixedly arranged in the first notch, and the second permanent magnet (8) is fixedly arranged in the second notch; and the outer surface of the first permanent magnet (2) is flush with the inner surface of the first end cover (1), and the outer surface of the second permanent magnet (8) is flush with the inner surface of the second end cover (7).
4. A hydraulic cylinder integrated with a variable magnetic flux type speed sensor according to claim 1, characterized in that both axial ends of the piston shaft (13) are aligned with the first permanent magnet (2) and the second permanent magnet (8), respectively, so that a magnetic field is formed around the piston shaft (13), and that the magnitude of the magnetic flux in the cylinder (3) is changed when the piston (4) slides on the piston shaft (13).
5. The hydraulic cylinder integrated with the variable magnetic flux type speed sensor according to claim 4, characterized in that a positioning sleeve (9) is arranged outside the coil (5), the positioning sleeve (9) and the piston shaft (13) are coaxially arranged, the positioning sleeve (9) extends to the first end cover (1) and the second end cover (7) along two axial ends of the piston shaft (13), and the piston (4) is slidably arranged outside the positioning sleeve (9).
6. A hydraulic cylinder integrated with a variable magnetic flux type speed sensor according to any one of claims 1 to 5, characterized in that the piston shaft (13) is further provided with linear hall elements (10, 11, 12) for measuring magnetic induction values, and that the position of the piston (4) on the piston shaft (13) is obtained on the basis of the magnetic induction values.
7. A hydraulic cylinder integrated with a variable magnetic flux type speed sensor according to claim 6, characterized in that three of said linear hall elements (10, 11, 12) are provided on said piston shaft (13) at intervals along said axial direction.
8. A hydraulic cylinder integrated with a variable magnetic flux speed sensor according to claim 1, characterized in that a first sealing ring (14) is arranged between the cylinder body (3) and the first end cap (1), and a second sealing ring (6) is arranged between the cylinder body (3) and the second end cap (7).
9. The hydraulic cylinder of an integrated variable magnetic flux type speed sensor according to claim 6, further comprising a controller connected to the coil (5), the linear hall elements (10, 11, 12) respectively for receiving the induced electromotive force obtained by the coil (5) and the magnetic induction intensity obtained by the linear hall elements (10, 11, 12); the controller acquires the moving speed of the piston (4) from the induced electromotive force, and acquires the position of the piston (4) on the piston shaft (13) from the linear hall elements (10, 11, 12).
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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102606670A (en) * 2012-03-23 2012-07-25 华东交通大学 Differential sensing type magnetorheological damper

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0812903D0 (en) * 2008-07-15 2008-08-20 Rota Eng Ltd Linear actuator and position sensing apparatus therefor
JP4842314B2 (en) * 2008-11-07 2011-12-21 株式会社アミテック Cylinder position detector
CN203939811U (en) * 2014-05-30 2014-11-12 诸暨市盛淼针织机械科技有限公司 A kind of cylinder
WO2017103853A1 (en) * 2015-12-15 2017-06-22 Mts Sensor Technologie Gmbh&Co.Kg Position sensing system
CN107676419B (en) * 2017-10-26 2019-04-05 东北大学 A kind of self-powered method of magnetic rheological liquid damper self-induction and damper
CN208419856U (en) * 2018-03-19 2019-01-22 上海同驭汽车科技有限公司 A kind of embedded hall displacement transducer of magnet and electronic hydraulic brake system
CN108195279A (en) * 2018-03-19 2018-06-22 上海同驭汽车科技有限公司 A kind of embedded hall displacement transducer of magnet and electronic hydraulic brake system
CN109795279B (en) * 2019-03-28 2020-08-28 西安科技大学 Control method of multi-mode hybrid suspension actuator
CN109795278B (en) * 2019-03-28 2020-08-28 西安科技大学 Multi-mode coordination switching control method for vehicle hybrid suspension actuator
CN111895900A (en) * 2020-08-24 2020-11-06 杰克缝纫机股份有限公司 Linear displacement high-precision measuring device and sewing machine
CN213902232U (en) * 2020-12-07 2021-08-06 南京艾驰电子科技有限公司 Hydraulic cylinder displacement detection device based on programmable linear Hall

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102606670A (en) * 2012-03-23 2012-07-25 华东交通大学 Differential sensing type magnetorheological damper

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