High-anti-interference linear Hall sensor suitable for voice coil motor servo valve

Abstract

The invention discloses a high-anti-interference linear Hall sensor suitable for a voice coil motor servo valve. The high-anti-interference linear Hall sensor comprises a mounting base, a telescopic cylinder, an adjusting sleeve, an opening cone clamping sleeve and a magnetic shielding operation sleeve. The adjusting sleeve is in transmission connection with the telescopic cylinder and is used for converting rotary motion into axial displacement of the telescopic cylinder; the magnetic shielding operation sleeve extrudes the open cone clamping sleeve through axial movement, so that the open cone clamping sleeve shrinks in the radial direction and holds and locks the adjusting sleeve. A thin-wall cup cover is arranged at the front end of the magnetic shielding operation sleeve, and a magnetic shielding labyrinth is formed by the outer wall of the thin-wall cup cover and the inner wall of the installation base and used for reducing interference of alternating magnetic leakage on the Hall chip. The structure is suitable for position feedback detection of the voice coil motor servo valve.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology, and particularly relates to a highly anti-interference linear Hall sensor suitable for voice coil motor servo valves. Background Technology

[0002] Electro-hydraulic servo valves are crucial actuators in industrial control and aerospace fields. Servo valves directly driven by voice coil motors typically require Hall effect sensors to detect the valve spool position. The installation accuracy of the Hall effect sensor and its interference immunity during operation affect the zero-position accuracy and closed-loop control performance of the servo valve.

[0003] Existing Hall effect sensors for voice coil motor servo valves are mostly threaded onto the valve end cap. During zeroing and tightening, the sensor body is prone to slight displacement or rotation due to thread clearance and tightening action, causing a change in the set zero position. For sensors with internally packaged linear Hall effect chips, even slight changes in the mounting orientation can alter the relative orientation between the Hall effect chip and the magnetic field, leading to output signal deviation.

[0004] Furthermore, existing sensor housings are mostly cylindrical, and the alternating leakage magnetic field generated by the voice coil motor during operation may enter along the mounting channel and superimpose on the Hall chip, adversely affecting the stability of position detection. Therefore, it is necessary to provide a linear Hall sensor that is easy to zero-lock and can reduce alternating leakage magnetic interference. Summary of the Invention

[0005] The technical problem to be solved: The present invention provides a high anti-interference linear Hall sensor suitable for voice coil motor servo valves, which can solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A highly interference-resistant linear Hall sensor suitable for voice coil motor servo valves includes a mounting base, a telescopic cylinder, an adjusting sleeve, an open cone clamp, and a magnetically shielded operating sleeve. The mounting base has a mounting cavity. The telescopic cylinder is disposed within the mounting cavity and is circumferentially limited and axially slidably connected to the mounting base. A Hall chip is mounted on the front end of the telescopic cylinder. The adjusting sleeve is disposed within the mounting base and is axially limited and circumferentially rotatably connected to the mounting base. The adjusting sleeve is drively connected to the telescopic cylinder, so that the rotational motion of the adjusting sleeve is converted into the axial sliding motion of the telescopic cylinder. The open cone clamp... The sleeve is mounted on the mounting base and fitted over the outside of the adjusting sleeve; the magnetic shielding operating sleeve slides in conjunction with the open cone sleeve, and the axial movement of the magnetic shielding operating sleeve is used to squeeze the open cone sleeve so that the open cone sleeve contracts radially and locks the adjusting sleeve; the front end of the magnetic shielding operating sleeve is provided with a thin-walled cup, and the outer wall of the thin-walled cup is provided with an everted lip, a constricted annular groove, a shielding cylinder and a magnetic blocking ring shoulder from front to back. When the magnetic shielding operating sleeve is in the locked position, the everted lip, the constricted annular groove, the shielding cylinder and the magnetic blocking ring shoulder respectively cooperate with the inner wall of the mounting base to form a magnetic shielding labyrinth.

[0007] Furthermore, the magnetic shielding operating sleeve and the adjusting sleeve are slidably connected, and the two cannot rotate relative to each other, so that when the magnetic shielding operating sleeve rotates, it drives the adjusting sleeve to rotate synchronously.

[0008] Furthermore, the adjusting sleeve has a spiral groove inside, and the telescopic cylinder has a transmission pin on its outer wall. The transmission pin slides in conjunction with the spiral groove. The telescopic cylinder and the mounting base are connected by a flat key to achieve a circumferential limiting connection.

[0009] Furthermore, the open conical sleeve is fixedly connected to the mounting base; the inner wall of the magnetic shielding operating sleeve is provided with a conical groove, and the outer wall of the open conical sleeve is provided with a conical surface that mates with the conical groove; when the magnetic shielding operating sleeve moves axially away from the open conical sleeve, the inner wall of the conical groove presses against and squeezes the conical surface, causing the open conical sleeve to contract radially.

[0010] Furthermore, the mounting base is provided with an adjustment groove and a fixing ring groove; a handle that extends out of the adjustment groove is hinged to the magnetic shielding operating sleeve, and a hook is fixedly connected to the handle. A spring is provided between the hook and the magnetic shielding operating sleeve for pushing the hook into the fixing ring groove; when the hook is engaged in the fixing ring groove, the magnetic shielding operating sleeve is axially locked.

[0011] Furthermore, it also includes a reset spring, which is disposed between the magnetic shielding operating sleeve and the adjusting sleeve; one end of the reset spring abuts against the magnetic shielding operating sleeve, and the other end abuts against the adjusting sleeve; the reset spring is used to push the magnetic shielding operating sleeve to reset toward the locked position.

[0012] Furthermore, the front end of the magnetic shielding operating sleeve and the thin-walled cup cover are integrally formed, and the thin-walled cup cover is made of magnetically conductive material.

[0013] Furthermore, the open cone sleeve has an axially extending opening slit, so that the open cone sleeve has the ability to elastically contract and open radially.

[0014] The present invention also provides a voice coil motor servo valve, including a valve core, a permanent magnet, and a high anti-interference linear Hall sensor as described in any one of the above; the permanent magnet is fixedly connected to the end face of the valve core, the mounting base is fixedly mounted on the end cover of the servo valve, the valve core drives the permanent magnet to extend into the thin-walled cup cover, and the Hall chip is arranged opposite to the permanent magnet.

[0015] Preferably, when the magnetic shielding operating sleeve is in the locked position, both the permanent magnet and the Hall chip are located inside the thin-walled cup cover.

[0016] Compared with the prior art, the advantages of the present invention are: 1. By means of the transmission connection between the adjusting sleeve and the telescopic cylinder, the adjustment action can be converted into the axial position adjustment of the Hall chip; at the same time, the circumferential limiting connection between the telescopic cylinder and the mounting base helps to reduce the possibility of circumferential deflection of the Hall chip during zeroing and locking.

[0017] 2. By cooperating with the open cone sleeve and the magnetic shielding operating sleeve, radial clamping locking of the adjusting sleeve can be achieved, which helps to reduce the impact of the locking process on the already set zero position.

[0018] 3. By setting a thin-walled cup cover at the front end of the magnetic shielding operating sleeve and making it cooperate with the inner wall of the mounting base to form a magnetic shielding labyrinth, it is beneficial to reduce the interference of alternating leakage magnetic field on the Hall chip when the voice coil motor is working. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of the present invention; Figure 2 For the present invention Figure 1 Sectional view along the AA direction; Figure 3 For the present invention Figure 1 Enlarged view at point I; Figure 4 This is a cross-sectional three-dimensional view of the adjusting sleeve of the present invention; Figure 5 This is a three-dimensional cross-sectional view of the adjusting sleeve of the present invention from another direction; Figure 6 This is a three-dimensional view of the open cone sleeve of the present invention; Figure 7 This is a three-dimensional view of the open cone sleeve of the present invention from another direction; Figure 8 This is a cross-sectional view of the present invention installed on a voice coil motor servo valve. Detailed Implementation

[0020] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0021] like Figures 1 to 8 As shown, a high anti-interference linear Hall sensor suitable for voice coil motor servo valves includes a mounting base 1, a magnetically shielded operating sleeve 4, a telescopic cylinder 10, an adjusting sleeve 12, an open cone clamp 14, a Hall chip 16, a reset spring 18, a handle 19, a hook 20, and a spring 21.

[0022] Mounting base 1 is used to fix the present invention on the servo valve end cover and to provide a mounting base for each moving part and locking part. Mounting base 1 is provided with adjusting groove 2 and fixing ring groove 3. Adjusting groove 2 is used to provide axial displacement stroke for handle 19 when unlocking and circumferential movement stroke when zeroing. The interior of mounting base 1 forms a mounting cavity for mounting telescopic cylinder 10, adjusting sleeve 12 and related mating structures. The inner wall of mounting base 1 also mates with the thin-walled cup cover at the front end of magnetic shielding operating sleeve 4 to form the magnetic shielding labyrinth described later.

[0023] The telescopic cylinder 10 is disposed inside the mounting base 1 and is capable of moving axially relative to the mounting base 1. The telescopic cylinder 10 and the mounting base 1 are connected by a circumferential limiting connection and an axial sliding connection. In this embodiment, the telescopic cylinder 10 and the mounting base 1 are connected by a flat key. The Hall chip 16 is mounted at the front end of the telescopic cylinder 10, and the axial position change of the telescopic cylinder 10 corresponds to the detection position change of the Hall chip 16.

[0024] The adjusting sleeve 12 is rotatably connected to the mounting base 1, and the adjusting sleeve 12 cannot move axially relative to the mounting base 1. The inner wall of the adjusting sleeve 12 is provided with a spiral groove 13, and the outer wall of the telescopic cylinder 10 is provided with a transmission pin 11, which is slidably engaged with the spiral groove 13. Therefore, when the adjusting sleeve 12 rotates relative to the mounting base 1, the spiral groove 13 drives the transmission pin 11 to move along a guide trajectory, thereby causing the telescopic cylinder 10 to move axially, thus driving the Hall chip 16 to perform axial adjustment. It should be understood that the engagement of the spiral groove 13 and the transmission pin 11 is only a preferred embodiment of the transmission connection between the adjusting sleeve 12 and the telescopic cylinder 10. Those skilled in the art can also use other transmission structures that can convert rotational motion into axial movement, such as a slanted cam.

[0025] An open conical sleeve 14 is disposed on the mounting base 1 and sleeved over the adjusting sleeve 12. In this embodiment, the open conical sleeve 14 is fixedly connected to the mounting base 1. The outer wall of the open conical sleeve 14 is provided with a conical surface 15, and an axially extending opening slit is provided on the open conical sleeve 14, giving it the ability to elastically contract and open radially. When an external force compresses it along the conical surface, the open conical sleeve 14 can contract radially inward to form a clamping force on the adjusting sleeve 12; when the external clamping force is released, the open conical sleeve 14 can spring back and open to release the clamping force on the adjusting sleeve 12.

[0026] The magnetic shielding operating sleeve 4 is fitted onto the outside of the adjusting sleeve 12 and is slidably connected to the adjusting sleeve 12 without being able to rotate relative to it. The magnetic shielding operating sleeve 4 has a conical groove 9, which engages with the conical surface 15 on the outer wall of the open conical clamp 14. When the magnetic shielding operating sleeve 4 moves axially relative to the adjusting sleeve 12, the relative position of the conical groove 9 and the conical surface 15 changes. When the magnetic shielding operating sleeve 4 moves away from the open conical clamp 14 to the locked position, the conical groove 9 presses against the conical surface 15, causing the open conical clamp 14 to radially contract and grip the adjusting sleeve 12, thereby locking the adjusting sleeve 12. When the magnetic shielding operating sleeve 4 moves towards the open conical clamp 14 to the unlocked position, the conical groove 9 moves away from the conical surface 15, the open conical clamp 14 opens, the adjusting sleeve 12 is unlocked, and adjustment can continue.

[0027] A return spring 18 is positioned between the magnetic shielding operating sleeve 4 and the adjusting sleeve 12. One end of the return spring 18 abuts against the magnetic shielding operating sleeve 4, and the other end abuts against the adjusting sleeve 12, used to push the magnetic shielding operating sleeve 4 to the locked position for reset. A handle 19 is hinged to the magnetic shielding operating sleeve 4, and an adjusting groove 2 is provided on the mounting base 1. The handle 19 extends outward through the adjusting groove 2. A hook 20 is fixedly connected to the handle 19, and a fixing ring groove 3 is provided on the mounting base 1. A spring 21 is positioned between the hook 20 and the magnetic shielding operating sleeve 4, used to drive the hook 20 to deflect towards the fixing ring groove 3, so that the hook 20 can engage in the fixing ring groove 3, thereby axially locking the magnetic shielding operating sleeve 4.

[0028] The front end of the magnetic shielding operating sleeve 4 is provided with a thin-walled cup cover. This thin-walled cup cover is preferably integrally formed with the magnetic shielding operating sleeve 4 and is preferably made of a magnetically conductive material. From front to back, the outer wall of the thin-walled cup cover is provided with an outwardly flared lip 5, a constricted annular groove 6, a shielding cylinder 7, and a magnetically blocking shoulder 8. When the magnetic shielding operating sleeve 4 is in the locked position, the outwardly flared lip 5, the constricted annular groove 6, the shielding cylinder 7, and the magnetically blocking shoulder 8 form a multi-level interval and turning fit structure with the inner wall of the mounting base 1, thereby constituting a magnetic shielding labyrinth. This magnetic shielding labyrinth is used to shield or bypass the alternating leakage magnetic field generated during the operation of the voice coil motor, reducing the possibility of the leakage magnetic field directly acting on the Hall chip 16.

[0029] From a magnetic circuit perspective, the outward-flaring lip 5 forms a front-end annular turning zone between itself and the inner wall of the mounting base 1, which can initially divert some of the leakage magnetic flux entering along the axial direction. The constricted annular groove 6 forms a locally constricted annular gap with the inner wall of the mounting base 1, causing the leakage magnetic flux to undergo further turning in this area. The shielding cylinder 7 extends axially, forming a longer mating path with the inner wall of the mounting base 1, which can increase the magnetic path length before the leakage magnetic flux reaches the area where the Hall chip 16 is located. The magnetic blocking shoulder 8 forms a further abrupt change in cross-section and path turning on the side near the Hall chip 16. Thus, the alternating leakage magnetic flux is diverted and turned in the multi-level structure composed of the outward-flaring lip 5, the constricted annular groove 6, the shielding cylinder 7, and the magnetic blocking shoulder 8, and forms a preferential bypass path along the magnetic conductive material and the periphery of the mounting base 1, making it difficult for it to directly penetrate into the central area inside the thin-walled cup cover.

[0030] Furthermore, since the thin-walled cup cover and the inner wall of the mounting base 1 form a multi-stage continuous fit rather than a single gap structure, the alternating leakage magnetic flux needs to pass through multiple magnetic reluctance variation regions sequentially before entering the vicinity of the Hall chip 16. For the time-varying leakage magnetic flux generated during the commutation process of the voice coil motor, the aforementioned multi-stage magnetic circuit turning and bypass structure helps to reduce the direct superposition of leakage magnetic flux at the Hall chip 16, thereby reducing the additional magnetic field disturbance sensed by the Hall chip 16. At the same time, the permanent magnet 17 and the Hall chip 16 are located inside the thin-walled cup cover. While forming an external leakage magnetic flux bypass path, the thin-walled cup cover can still maintain the relative stability of the main magnetic field action area used for position detection between the permanent magnet 17 and the Hall chip 16, which is beneficial to improving the position feedback stability of the servo valve under dynamic operating conditions.

[0031] In one embodiment, the aforementioned high anti-interference linear Hall sensor is applied in a voice coil motor servo valve. The voice coil motor servo valve includes a valve core, a permanent magnet 17, and the aforementioned high anti-interference linear Hall sensor. The permanent magnet 17 is fixedly connected to the end face of the valve core, and the mounting base 1 is fixedly mounted on the servo valve end cover. When the valve core moves, it drives the permanent magnet 17 to extend into the thin-walled cup cover. The Hall chip 16 is positioned opposite to the permanent magnet 17.

[0032] The usage process of this embodiment is as follows: First, the permanent magnet 17 is fixedly connected to the end face of the servo valve core, and then the linear Hall sensor of the present invention is fixedly installed on the end cover of the servo valve, so that the valve core drives the permanent magnet 17 to extend into the thin-walled cup cover at the front end of the magnetic shielding operation sleeve 4, and the Hall chip 16 is arranged opposite to the permanent magnet 17.

[0033] When zeroing is required, the operator first disengages the hook 20 from the fixed ring groove 3, thereby releasing the axial lock on the magnetic shielding operating sleeve 4. Then, the operator pushes the handle 19 to move the magnetic shielding operating sleeve 4 against the force of the return spring 18 in the unlocking direction, causing the conical groove 9 to move away from the conical surface 15. The open conical clamp 14 opens under its own elastic force, thus releasing the clamping force on the adjusting sleeve 12. At this time, the operator moves the handle 19 along the adjusting groove 2, causing the magnetic shielding operating sleeve 4 to rotate synchronously with the adjusting sleeve 12. Since the adjusting sleeve 12 is rotatably connected to the mounting base 1 and cannot move axially relative to it, while the telescopic cylinder 10 is engaged with the spiral groove 13 via the transmission pin 11 and its rotation is restricted by the circumferential limiting connection with the mounting base 1, the rotation of the adjusting sleeve 12 is converted into axial movement of the telescopic cylinder 10, which in turn drives the Hall chip 16 to move axially until the Hall chip 16 is adjusted to the required zero position.

[0034] After zeroing is completed, the operator releases handle 19. Under the action of return spring 18, the magnetic shielding operating sleeve 4 returns to the locked position away from the open conical sleeve 14. The conical groove 9 presses against the conical surface 15 again, causing the open conical sleeve 14 to radially contract and re-clamp the adjusting sleeve 12. At the same time, the hook 20 re-enters the fixing ring groove 3 under the action of spring 21, thereby re-locking the magnetic shielding operating sleeve 4. Since the open conical sleeve 14 implements a radial clamping lock on the adjusting sleeve 12, and the telescopic cylinder 10 is circumferentially limited to the mounting base 1, the possibility of axial displacement and circumferential deflection of the telescopic cylinder 10 is reduced during the locking process.

[0035] When the servo valve enters the working state, the voice coil motor may generate alternating leakage magnetic field during the commutation process. In this embodiment, the Hall chip 16 and the permanent magnet 17 are located inside the thin-walled cup cover. The magnetic shielding labyrinth formed by the outward-flaring lip 5, the constricted annular groove 6, the shielding cylinder 7, and the magnetic blocking ring shoulder 8 with the inner wall of the mounting base 1 can block and bypass this alternating leakage magnetic field, thereby reducing the impact of the alternating leakage magnetic field on the output signal of the Hall chip 16.

[0036] The above is merely one specific embodiment of the present invention. Conventional modifications and direct derivations made by those skilled in the art without departing from the concept of the present invention should all fall within the protection scope of the present invention.

Claims

1. A highly interference-resistant linear Hall sensor suitable for voice coil motor servo valves, characterized in that, include: Mounting base (1); Telescopic cylinder (10), the telescopic cylinder (10) is disposed in the mounting base (1) and is circumferentially limited and axially slidably connected to the mounting base (1). A Hall chip (16) is installed at the front end of the telescopic cylinder (10). Adjusting sleeve (12), the adjusting sleeve (12) is disposed in the mounting base (1) and is axially limited and circumferentially rotatably connected to the mounting base (1); the adjusting sleeve (12) is pulsatorically connected to the telescopic cylinder (10) and is configured to convert the rotational motion of the adjusting sleeve (12) into the axial sliding motion of the telescopic cylinder (10); An open cone sleeve (14) is disposed on the mounting base (1) and sleeved on the outside of the adjusting sleeve (12); And a magnetic shielding operating sleeve (4), which is slidably engaged with the open cone sleeve (14); the axial movement of the magnetic shielding operating sleeve (4) is configured to squeeze the open cone sleeve (14) so ​​that the open cone sleeve (14) radially contracts and clamps and locks the adjusting sleeve (12). The front end of the magnetic shielding operation sleeve (4) is provided with a thin-walled cup cover. The outer wall of the thin-walled cup cover is provided with an outwardly turned lip (5), a constricted annular groove (6), a shielding cylinder (7), and a magnetic blocking ring shoulder (8) from front to back. When the magnetic shielding operation sleeve (4) is in the locked position, the outwardly turned lip (5), the constricted annular groove (6), the shielding cylinder (7), and the magnetic blocking ring shoulder (8) respectively cooperate with the inner wall of the mounting base (1) to form a magnetic shielding labyrinth.

2. The high anti-interference linear Hall sensor according to claim 1, characterized in that, The magnetic shielding operation sleeve (4) is slidably connected to the adjustment sleeve (12), and the two cannot rotate relative to each other, so that when the magnetic shielding operation sleeve (4) rotates, it drives the adjustment sleeve (12) to rotate synchronously.

3. The high anti-interference linear Hall sensor according to claim 1, characterized in that, The adjusting sleeve (12) has a spiral groove (13) inside, and the telescopic cylinder (10) has a transmission pin (11) on its outer wall. The transmission pin (11) slides with the spiral groove (13). The telescopic cylinder (10) and the mounting base (1) are connected by a flat key to achieve the circumferential limiting connection.

4. The high anti-interference linear Hall sensor according to claim 1, characterized in that, The open conical sleeve (14) is fixedly connected to the mounting base (1); the inner wall of the magnetic shielding operation sleeve (4) is provided with a conical groove (9), and the outer wall of the open conical sleeve (14) is provided with a conical surface (15) that cooperates with the conical groove (9); when the magnetic shielding operation sleeve (4) moves axially away from the open conical sleeve (14), the inner wall of the conical groove (9) presses against and squeezes the conical surface (15), causing the open conical sleeve (14) to contract radially.

5. The high anti-interference linear Hall sensor according to any one of claims 1 to 4, characterized in that, The mounting base (1) is provided with an adjustment groove (2) and a fixing ring groove (3); the magnetic shielding operation sleeve (4) is hinged with a handle (19) that extends out of the adjustment groove (2), and a hook (20) is fixedly connected to the handle (19). A spring (21) is provided between the hook (20) and the magnetic shielding operation sleeve (4) for pushing the hook (20) into the fixing ring groove (3); when the hook (20) is engaged in the fixing ring groove (3), the magnetic shielding operation sleeve (4) is axially locked.

6. The high anti-interference linear Hall sensor according to claim 5, characterized in that, It also includes a reset spring (18) disposed between the magnetic shielding operating sleeve (4) and the adjusting sleeve (12); one end of the reset spring (18) abuts against the magnetic shielding operating sleeve (4) and the other end abuts against the adjusting sleeve (12); the reset spring (18) is configured to push the magnetic shielding operating sleeve (4) to reset toward the locked position.

7. The high anti-interference linear Hall sensor according to claim 1, characterized in that, The front end of the magnetic shielding operating sleeve (4) and the thin-walled cup cover are integrally formed, and the thin-walled cup cover is made of magnetically conductive material.

8. The high anti-interference linear Hall sensor according to claim 1 or 4, characterized in that, The open cone sleeve (14) has an axially extending opening slit, so that the open cone sleeve (14) has the ability to radially elastically contract and open.

9. A voice coil motor servo valve, characterized in that, The device includes a valve core, a permanent magnet (17), and a high anti-interference linear Hall sensor as described in any one of claims 1 to 8. The permanent magnet (17) is fixedly connected to the end face of the valve core, and the mounting base (1) is fixedly mounted on the end cover of the servo valve. The valve core drives the permanent magnet (17) to extend into the thin-walled cup cover, and the Hall chip (16) is arranged opposite to the permanent magnet (17).

10. The voice coil motor servo valve according to claim 9, characterized in that, When the magnetic shielding operating sleeve (4) is in the locked position, the permanent magnet (17) and the Hall chip (16) are both located inside the thin-walled cup cover.

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