An improved EPS sensor unit assembly
By simplifying the design of sensor unit assembly, reducing the number of parts, eliminating exhaust holes, and improving fixing and connecting methods, the problems of multiple parts and complex assembly in traditional designs are solved, achieving cost reduction and performance guarantee effects.
Patent Information
- Application Number
- CN201911402266.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-12-31
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2039-12-31
AI Technical Summary
The traditional EPS sensor unit assembly design has a large number of parts, the assembly process is complex, and the need to add exhaust holes and positioning pins, resulting in increased cost and process complexity.
An improved EPS sensor unit assembly is designed to reduce the number of parts by simplifying the design structure of the input shaft, steering gear and torsion rod, cancel the exhaust holes, and fix and connect parts through interference fit and pressing rivets.
It realizes the reduction of the number of sensor unit assembly parts, simplifies assembly processes, reduces costs, and ensures the performance and reliability of the original design.
Smart Images
Figure CN111038585B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of automobile steering column parts, in particular to an improved EPS sensor unit assembly. Background Art
[0002] In the design of the automobile steering gear, the torque applied by the driver to the steering wheel is transmitted to the component input shaft of the sensor unit subassembly through the steering intermediate shaft. The driver turns the steering wheel and transmits the hand torque to the sensor unit component of the lower steering gear - the input shaft through the upper steering column. The input shaft rotates after being subjected to the torsional torque. The torque sensor in the sensor unit component of the lower steering gear detects the rotation of the input shaft, and the torque sensor sends a power assistance request signal to the EPS power assistance motor. After receiving the signal from the torque sensor, the EPS power assistance motor drives the EPS rack to move. The movement of the EPS rack drives the component steering gear on the sensor unit. The sensor unit is forced to rotate axially to compensate for the torsional torque of the input shaft, thereby achieving the power assistance effect of the EPS electronic power steering gear.
[0003] In the design of the traditional sensor unit assembly, the input shaft of the component is connected to the steering gear through a torsion bar. To ensure that the torsion bar is firmly connected to the input shaft and the torsion bar has an interference fit with the input shaft, it is necessary to add an exhaust hole on the input shaft. To prevent the torsion bar and the input shaft from rotating radially, it is necessary to drill holes on the input shaft and the torsion bar and insert positioning pins, so the assembly process is relatively complicated. To ensure that the torsion bar fits in the input shaft and the steering gear and the seal is reliable, it is necessary to add a pipe assembly and an O-ring assembly on the torsion bar, which increases the cost of parts.
[0004] Therefore, it is very necessary to design an EPS sensor unit assembly that reduces the number of parts in the current sensor assembly design while ensuring the performance of the original design. Summary of the invention
[0005] The present invention overcomes the difficulties of the prior art and designs an EPS sensor unit assembly which reduces the number of parts in the current sensor assembly design while ensuring the performance of the original design.
[0006] In order to achieve the above object, the present invention designs an improved EPS sensor unit assembly, including: an input shaft, a torsion bar, a bearing, a torque magnet, a torque sensor, and a steering gear, characterized in that:
[0007] One end of the input shaft that is connected with the steering gear is fixed with two arc-shaped limiting bosses at opposite positions, and a pressure riveting point 1 is provided on the arc surface of the one end of the input shaft that is connected with the steering gear;
[0008] One end of the steering gear that is connected to the input shaft is provided with two sets of grooves that are opposite to each other, and the grooves are matched with the arc-shaped limiting bosses. A second rivet point and a positioning point are provided on the arc surface of the one end of the steering gear that is connected to the input shaft.
[0009] One end of the torsion bar is a spline end, which is used to fit and fix with the inner hole of the input shaft, and the other end of the torsion bar is a smooth cylindrical end, which is used to fit and fix with the steering gear;
[0010] The torque magnet is composed of a fixed base and a magnet. The upper end of the fixed base extends outwardly to form a sector-shaped plane, and the magnet is fixed on the sector-shaped plane.
[0011] The smooth cylindrical end of the torsion bar is inserted into the inner hole of the steering gear, so that the smooth cylindrical end of the torsion bar and the steering gear have an interference fit, and the bearing is pressed into the bearing matching hole of the inner hole of the input shaft, so that the outer edge of the bearing and the input shaft also have an interference fit, and then the spline end of the torsion bar passes through the bearing and extends into the torsion bar matching hole of the inner hole of the input shaft to fix the torsion bar and the input shaft, and the inner ring of the bearing has an interference fit with the torsion bar. After the torsion bar is pressed into place, the groove on the steering gear and the arc-shaped limiting boss on the input shaft are just engaged and fixed, the torque magnet is set at the position where the rivet point one is set on the outer edge of the input shaft, and the two are fixed by rivet, and the torque sensor is set at the position where the rivet point two and the positioning point are set on the outer edge of the steering gear, and the two are also fixed by rivet.
[0012] The inner hole of the input shaft is a stepped hole.
[0013] A crescent groove is provided on one end of the input shaft away from the steering gear, and two sides of the crescent groove are planes.
[0014] A section of helical teeth is arranged on the surface of the steering gear at one end away from the input shaft.
[0015] The bearing is a needle roller bearing.
[0016] Among them, the positions of the planes on both sides of the crescent groove are staggered.
[0017] Compared with the prior art, the present invention simplifies the component structure of the sensor unit subassembly, especially saves the parts-tubes in the traditional sensor unit subassembly; changes the design structure of the input shaft, steering gear and torsion bar, and improves the reliability of the connection between the input shaft and the steering gear; simplifies the process assembly steps, and the torsion bar and the input shaft do not need to be fixed with locating pins, saving assembly costs; and eliminates the exhaust hole on the input shaft, simplifying the input shaft processing technology. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a side view of the input shaft in the present invention.
[0019] Figure 2It is a BB cross-sectional view of the input shaft in the present invention.
[0020] Figure 3 It is a cross-sectional view of the input shaft in the present invention.
[0021] Figure 4 It is a CC cross-sectional view of the input shaft in the present invention.
[0022] Figure 5 It is a side view of the steering gear in the present invention.
[0023] Figure 6 It is the bb cross-sectional view of the steering gear in the present invention.
[0024] Figure 7 It is a top view of the crescent groove of the input shaft in the present invention.
[0025] Figure 8 It is a side view of the crescent groove of the input shaft in the present invention.
[0026] Fig. 9 It is a top view of the groove of the steering gear in the present invention.
[0027] Fig.10 It is a schematic diagram of the structure of the torsion bar in the present invention.
[0028] Fig.11 It is a cross-sectional view of the bearing in the present invention.
[0029] Fig.12 It is a schematic diagram of the structure of the torque magnet in the present invention.
[0030] Fig.13 Schematic diagram of magnetic field pole distribution of the torque magnet in the present invention.
[0031] Fig.14 It is a schematic diagram of the structure of the torque sensor in the present invention.
[0032] Fig.15 It is a partial enlarged view of the magnetic sensing area of the torque sensor in the present invention.
[0033] Fig.16 It is an assembly schematic diagram of the present invention. DETAILED DESCRIPTION
[0034] The present invention is further described in conjunction with the accompanying drawings.
[0035] See also Figures 1 to 16 The present invention designs an improved EPS sensor unit assembly, including: an input shaft, a torsion bar, a bearing, a torque magnet, a torque sensor, and a steering gear.
[0036] See also Figure 1~2 and Figure 4In the present invention, one end of the input shaft 1 that is connected to the steering gear 2 is fixed with two arc-shaped limiting bosses 1-1 in opposite positions, which are used to limit the steering gear. The arc surface of one end of the input shaft 1 that is connected to the steering gear 2 is provided with rivet points 1-2. There are three rivet points, which are rotationally symmetrical about the axis of the input shaft and are used to position and connect with the torque magnet.
[0037] See also Figure 3 In the present invention, the inner hole of the input shaft 1 is a stepped hole, the large hole section on the left side of the inner hole of the input shaft is the mating surface with the bearing, called the bearing mating hole 1-3, and the small hole section on the right side of the inner hole of the input shaft is the mating surface with the torsion bar, called the torsion bar mating hole 1-4.
[0038] See also Figure 7 and Figure 8 The small end interface of the input shaft in the present invention is used to connect the universal joint of the upper pipe column. The universal joint will transmit the rotational torque of the client to the input shaft. The crescent groove 2-4 for bolt positioning is used for bolt fixation after matching with the universal joint, ensuring that the input shaft and the universal joint match reliably without axial movement and radial displacement. The planes 2-5 on both sides of the crescent groove 2-4 are used to bear and resist the rotational torque transmitted by the universal joint as a force-bearing surface. The plane 2-5 is made in an asymmetric form to ensure error-proof assembly with the universal joint.
[0039] See also Figure 5 In the present invention, the steering gear 2 is divided into a working area and an installation area. The working area is composed of a helical tooth profile. The function of the working area is to cooperate with the helical tooth profile on the EPS rack, and the rack can drive the steering gear to rotate. The helical tooth profile of the steering gear working area is different according to the tooth profile parameters calculated by different projects.
[0040] See also Fig. 9 In the present invention, one end of the steering gear 2 that is connected to the input shaft 1 is provided with two sets of grooves 2-1 that are positioned opposite to each other. The grooves 2-1 cooperate with the arc-shaped limiting boss 1-1. After the two cooperate, there will be a mutual limiting effect, and the two can only make a relative rotation angle of about 6°.
[0041] See also Figure 6 In the present invention, a rivet point 2-2 and a positioning point 2-3 are provided on the arc surface of one end of the steering gear 2 which is connected to the input shaft 1. The number of the rivet points 2-2 is 3, which are rotationally symmetrical about the axis of the steering gear. There is one positioning point, both of which are used for positioning the steering gear on the sensor unit assembly line.
[0042] See also Fig.10In the present invention, the torsion bar can be divided into three parts: a steering gear matching area, an input shaft matching area and a bearing matching area. The steering gear matching area of the torsion bar is designed as a smooth cylindrical end 3-2, which is used to match and fix with the steering gear 2. A certain pressure needs to be applied to press it into the torsion bar matching surface of the steering gear, and the steering gear torsion bar matching surface of the steering gear matching area of the torsion bar is an interference fit;
[0043] The input shaft matching area of the torsion bar 3 is the spline end 3-1, which is used to match and fix with the inner hole of the input shaft 1. When the spline end 3-1 is pressed into the inner hole of the input shaft, gas in the inner hole of the input shaft is discharged from the gap of the spline of the torsion bar. Therefore, the input shaft does not need to drill a hole on the upper part of the matching surface between the input shaft and the torsion bar as in the traditional design to ensure the discharge of gas in the input shaft. Therefore, the torsion bar design can save the process drilling steps. The matching of the torsion bar spline and the input shaft torsion bar matching surface is tight, and the torsion bar cannot rotate in the inner hole of the input shaft. Therefore, compared with the traditional sensor unit assembly, it saves the installation of locating pins on the input shaft and the torsion bar, thereby ensuring that the input shaft and the torsion bar will not rotate radially, thereby saving parts cost and process assembly cost.
[0044] The bearing matching area of the torsion bar 3 is used for interference fit with the bearing.
[0045] See also Fig.11 The bearing 4 in the present invention is a needle roller bearing, which is mainly composed of three parts, namely a stamped outer ring 4-1, a retainer 4-2 and a needle roller assembly 4-3; the stamped outer ring 4-1 is made of SAE1010 and meets the requirements of J403, the retainer 4-2 is made of SPCC and meets the requirements of JIS G3141, and the needle roller assembly 4-3 is composed of 15 needle rollers made of GCr15 and meets the requirements of GB / T18254.
[0046] See also Fig.12 The torque magnet 5 in the present invention is composed of a fixed base 5-1 and a magnet 5-2. The fixed base 5-1 is a cylindrical metal sheet, and the surface needs to be galvanized with a coating thickness of 25g / m 2 The inner hole of the fixed base matches the outer diameter of the cylindrical surface at the input shaft BB. 3x120° rivet points need to be riveted on the fixed base 5-1, and the rivet points need to correspond to the three rivet points on the input shaft. Therefore, after the torque magnet 5 is riveted and fixed, the torque magnet 5 will not have radial rotation and axial displacement on the input shaft 1, ensuring that the torque magnet 5 can be reliably fixed on the input shaft 1.
[0047] The upper end of the fixed base 5-1 extends outwardly to form a sector-shaped plane of about 85°, and the magnet 5-2 is fixed on the sector-shaped plane. Fig.13 The magnet 5-2 is designed with five magnetic field poles, which are evenly distributed on the 75° sector magnet. The poles on the magnet 5-2 are S, N, S, N, and S respectively.
[0048] See also Figures 14 and 15 The torque sensor in the present invention is a capacitive torque sensor, which can generate the torque on the input shaft of the sensor unit assembly and the change of the relative angle between the input shaft and the steering gear by detecting the change of the magnetic field between the torque magnet and the torque magnet.
[0049] See also Fig.15 ,There are three magnetic poles in the sensing area of the torque sensor, namely N, S, and N.
[0050] When the sensor unit is in the neutral state, the magnetic sensing area of the torque magnet is just above the sensing area of the torque sensor. When the torque magnet and the torque sensor (which can also be regarded as the input shaft and the steering gear, because the former two are respectively fixed on the latter two) rotate relative to each other, a magnetic field signal is generated. The internal components of the torque sensor will convert this magnetic field signal into an electrical signal, which will transmit the torque signal to the power assist mechanism through the signal transceiver port of the torque sensor.
[0051] In the specific assembly, assemble according to the following steps:
[0052] 1. Press the smooth cylindrical end 3-2 of the torsion bar 3 into the inner hole of the steering gear 2. The fit is an interference fit. After a certain pressing force is applied to the torsion bar 3, the torsion bar 3 is completely pressed into the inner hole of the steering gear 2. The above two parts are assembled to form a steering gear subassembly.
[0053] 2. Press two bearings 4 into the inner hole of the input shaft 1 in sequence. The outer diameter of the bearing 4 and the inner hole of the input shaft 1 are interference fit. A certain pressing force needs to be applied when the bearing 4 is pressed into the inner hole of the input shaft 1. After the above two parts are assembled, it is called the input shaft sub-assembly;
[0054] 3. Press the spline end 3-1 of the torsion bar 3 in the steering gear subassembly into the inner hole of the input shaft 1. After the spline end 3-1 of the torsion bar 3 is pressed into the input shaft 1, the torsion bar 3 cannot rotate in the inner hole of the input shaft 1;
[0055] 4. Match the inner hole of the fixed base 5-1 of the torque magnet 5 with the riveted cylindrical surface on the input shaft 1, and punch 3x120° rivet points corresponding to the riveting point 1-2 on the fixed base 5-1 of the torque magnet 5; match the inner hole of the fixed base of the torque sensor 6 with the riveted cylindrical surface on the steering gear 2, and punch 3x120° rivet points corresponding to the riveting point 2-2 on the fixed base of the torque sensor 6 to complete the assembly.
Claims
1. An improved EPS sensor unit assembly, comprising: Input shaft, torsion bar, bearing, torque magnet, torque sensor, steering gear, characterized in that: One end of the input shaft (1) that is matched with the steering gear (2) is fixed with two arc-shaped limiting bosses (1-1) located opposite to each other, and a rivet point 1 (1-2) is provided on the arc surface of the one end of the input shaft (1) that is matched with the steering gear (2); One end of the steering gear (2) that is matched with the input shaft (1) is provided with two sets of grooves (2-1) that are opposite to each other, the grooves (2-1) are matched with the arc-shaped limiting boss (1-1), and a second rivet point (2-2) and a positioning point (2-3) are provided on the arc surface of one end of the steering gear (2) that is matched with the input shaft (1); One end of the torsion bar (3) is a spline end (3-1) for being matched and fixed with the inner hole of the input shaft (1), and the other end of the torsion bar (3) is a smooth cylindrical end (3-2) for being matched and fixed with the steering gear (2); The torque magnet (5) is composed of a fixed base (5-1) and a magnet (5-2); the upper end of the fixed base (5-1) extends outwardly to form a sector-shaped plane, and the magnet (5-2) is fixed on the sector-shaped plane; The smooth cylindrical end (3-2) of the torsion bar (3) is inserted into the inner hole of the steering gear (2) so that the smooth cylindrical end (3-2) of the torsion bar (3) and the steering gear (2) are interference fit, the bearing (4) is pressed into the bearing matching hole (1-3) of the inner hole of the input shaft (1) so that the outer edge of the bearing (4) and the input shaft (1) are also interference fit, and then the spline end (3-1) of the torsion bar (3) passes through the bearing (4) and extends into the torsion bar matching hole (1-4) of the inner hole of the input shaft (1) so that the torsion bar (3) and the input shaft (1) are fixedly connected. The inner ring of the bearing (4) is interference-fitted with the torsion bar (3). After the torsion bar (3) is pressed into place, the groove (2-1) on the steering gear (2) and the arc-shaped limiting boss (1-1) on the input shaft (1) are just engaged and fixed. The torque magnet (5) is sleeved on the position where the rivet point 1 (1-2) is provided on the outer edge of the input shaft (1), and the two are fixed by rivet. The torque sensor (6) is sleeved on the position where the rivet point 2 (2-2) and the positioning point (2-3) are provided on the outer edge of the steering gear (2), and the two are also fixed by rivet.
2. An improved EPS sensor unit assembly according to claim 1, characterized in that: The inner hole of the input shaft (1) is a stepped hole.
3. An improved EPS sensor unit assembly according to claim 1, characterized in that: A crescent groove (2-4) is provided on one end of the input shaft (1) away from the steering gear (2), and two sides of the crescent groove (2-4) are flat surfaces (2-5).
4. The improved EPS sensor unit assembly according to claim 1, characterized in that: A section of helical teeth is provided on a surface of the steering gear (2) at an end away from the input shaft (1).
5. The improved EPS sensor unit assembly according to claim 1, characterized in that: The bearing (4) is a needle roller bearing.
6. An improved EPS sensor unit assembly according to claim 3, characterized in that: The positions of the planes (2-5) on both sides of the crescent groove (2-4) are staggered.
Citation Information
Patent Citations
An improved EPS sensor unit assembly is provided
CN211918823U