Passenger car electric steering gear rack and pinion clearance measurement adjusting mechanism

Abstract

The invention discloses a passenger car electric steering gear rack and gear clearance measurement adjusting mechanism, which comprises a back plate, a telescopic mechanism, an inner displacement detection probe, an outer displacement detection probe, a tightening mechanism and a control unit, and is characterized in that the telescopic mechanism is mounted on the side surface of the back plate, a rotating mechanism is arranged on the side surface of the tightening mechanism, and the telescopic mechanism drives the rotating mechanism to move; according to the invention, dynamic loading and dynamic unloading between the gear and the rack in actual use of the steering gear and the temperature change condition in the steering gear are simulated, so that the gear and the rack with gaps are prevented from deviating in the mounting position under the influence of external factors, and the stability of the gear and the rack is improved. Therefore, the detection precision of the inner displacement detection probe and the outer displacement detection probe is effectively improved, and the accuracy of calculating the gap between the gear and the rack can be further improved.

Description

Technical Field

[0001] The invention relates to a gear rack clearance adjustment of an electric steering gear, in particular to a gear rack clearance measurement and adjustment mechanism of an electric steering gear of a passenger car. Background Art

[0002] The steering gear, also known as the steering machine or steering gear, is the most critical part of the car steering system. There are many types of steering gears, such as rack and pinion type, recirculating ball type, worm crank pin type, power steering, etc. Its main function is to appropriately transform the steering torque and steering angle from the steering wheel, and then output it to the steering rod mechanism, so that the car can steer. In short, the steering gear is essentially a reduction transmission device.

[0003] In the rack and pinion steering gear, accurate clearance adjustment is a key factor to ensure the performance and safety of the steering system. The steering gear needs to be strictly adjusted before leaving the factory to ensure that it can work properly when installed on the vehicle. Since a small change in the clearance may cause a large fluctuation in the steering performance, the accuracy of detection and adjustment is very high. If the clearance is too tight, it may cause heavy steering and affect driving comfort; if the clearance is too loose, it may cause unstable steering, reduce vehicle handling, and may produce abnormal noise, affecting the driving experience. Therefore, ensuring that the clearance adjustment before leaving the factory is accurate is an important measure to ensure the optimal performance of the steering system and driving safety.

[0004] In a rack and pinion steering gear, certain manufacturing tolerances will occur during the production process of the steering gear, and the fitting clearance between the internal gear and rack may change and exceed the predetermined clearance range. In order to restore the normal working state of the steering gear, it is necessary to detect and adjust the clearance of the steering gear rack and pinion. The detection accuracy of the rack and pinion clearance directly affects the adjustment effect and the performance of the steering system. Since a slight change in the clearance may cause a large fluctuation in the steering performance, the detection accuracy is required to be high. When accurately adjusting the clearance, being too tight or too loose may affect the flexibility and safety of the steering system. Being too tight may cause heavy steering and affect driving comfort; being too loose may cause unstable steering, reduce vehicle handling, and may produce abnormal noise, affecting the driving experience. Ensuring the high accuracy of the clearance detection is crucial to ensuring the optimal performance of the steering system.

[0005] Therefore, it is necessary to design a gear rack clearance measurement and adjustment mechanism for a passenger car electric steering gear, which is used to accurately measure and precisely control the gear rack clearance. Summary of the invention

[0006] The invention overcomes the shortcomings of the prior art and provides a mechanism for measuring and adjusting the clearance of a rack and pinion of an electric steering gear of a passenger car.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a gear rack clearance measurement and adjustment mechanism for an electric steering gear of a passenger car, comprising: a back plate, a telescopic mechanism, an inner displacement detection probe, an outer displacement detection probe, a tightening mechanism and a control unit, wherein the telescopic mechanism is installed on the side of the back plate, a rotating mechanism is provided on the side of the telescopic mechanism, and drives the rotating mechanism, the inner displacement detection probe and the outer displacement detection probe to move, and a two-axis motion platform is installed on the side of the back plate to control the back plate to move and position accurately on the X-axis and the Z-axis;

[0008] The telescopic mechanism comprises: a moving plate and a first telescopic cylinder; the moving plate and the back plate slide up and down, and the first telescopic cylinder is fixed to the back plate;

[0009] The side of the movable plate is fixedly mounted with a first rotating sleeve and a second rotating sleeve, and the tightening mechanism comprises: a tightening shaft, a fixed shaft and a rotating block; the end of the rotating block is fixedly mounted with the first rotating sleeve, the tightening shaft sleeve is arranged in the middle of the fixed shaft, the end of the tightening shaft is rotatably mounted with the second rotating sleeve, the inner displacement detection probe passes through the tightening shaft, and the other end of the tightening shaft is provided with a slot adapted to the adjustment position in the steering gear;

[0010] The control unit simulates the actual load state of the steering gear, controls the detection positions of the inner displacement detection probe and the outer displacement detection probe, detects the displacement data of the gear and the rack, calculates the actual gap value between the gear and the rack, controls the operation of the rotating mechanism, and adjusts the gap of the gear and the rack in real time.

[0011] In a preferred embodiment of the present invention, the rotating mechanism includes: a servo motor, a first gear and a second gear; the first gear and the second gear are both located in the second rotating sleeve and are rotatably connected to the second rotating sleeve, the first gear and the second gear are meshed, the servo motor is fixed to the movable plate, the output end of the servo motor is fixed to the axial center position of the first gear, and the end of the tightening shaft is fixed to the axial center position of the second gear.

[0012] In a preferred embodiment of the present invention, a detection channel is provided at the axial center of the tightening shaft to facilitate the telescopic movement of the inner displacement detection probe.

[0013] In a preferred embodiment of the present invention, an internal displacement sensor is provided at the end of the internal displacement detection probe, and an external displacement sensor is provided at the end of the external displacement detection probe. A fixing plate is fixed to the side of the internal displacement sensor, and the fixing plate is fixed to the side of the servo motor. The external displacement sensor is located on the side of the tightening mechanism and is fixed to the movable plate.

[0014] In a preferred embodiment of the present invention, both the external displacement sensor and the internal displacement sensor are laser sensors.

[0015] A method for measuring and adjusting the clearance between a rack and pinion of an electric steering gear of a passenger car, using the mechanism for measuring and adjusting the clearance between a rack and pinion of an electric steering gear of a passenger car as claimed in any one of the claims, comprising the following steps:

[0016] S1. Use the internal displacement detection probe to monitor the displacement of the rack in real time, and the external displacement detection probe to monitor the rotational displacement of the gear in real time;

[0017] S2. Establish a mathematical model, simulate the offset of the gear and rack under the actual load state based on the actual load state of the steering gear, calculate the position change of the inner displacement detection probe and the outer displacement detection probe through the offset, adjust the inner displacement detection probe and the outer displacement detection probe in real time, so as to accurately obtain the displacement data of the gear and rack, and transmit the collected data to the control unit;

[0018] S3, preprocessing the displacement data of the gear and rack, integrating the preprocessed real-time data, respectively calculating the displacement difference of the two sensors, and obtaining the actual clearance value G of the gear and rack;

[0019] S4. Set the target clearance value G of the gear rack based on the actual load state. t , the actual gap value G obtained by actual measurement and the target gap value G t Compare and calculate the actual gap value G and the target gap value G t If ΔG is a positive value, the tightening mechanism is controlled to reduce the gear rack clearance. If ΔG is a negative value, the tightening mechanism is controlled to increase the gear rack clearance until the target clearance value G is reached. t .

[0020] In a preferred embodiment of the present invention, in said S2, the actual load state includes: dynamic loading, dynamic unloading, and temperature;

[0021] The internal displacement detection probe and the external displacement detection probe are adjusted in real time. Specifically, a mathematical model is established by combining dynamic loading, dynamic unloading, and temperature. Where d(t) represents the offset of the rack or gear at time t, F(t) represents the load force acting on the gear or rack at time t, k(t) represents the stiffness coefficient of the gear or rack, which represents the gear's ability to resist deformation, L0 represents the center distance between the gear and the rack in the initial state, which is used as the reference length for calculating thermal expansion, a represents the thermal expansion coefficient of the gear or rack material, which represents the expansion rate of the material with temperature changes, and T t -T represents the difference between the temperature at time t and the reference temperature;

[0022] Set the target value d(0), calculate the offset d(t) and the target value d(0), and get the actual detection position d. Combined with the mathematical formula, we get d(0) represents the initial target position of the rack or gear, and the control unit is used to control the position adjustment of the inner displacement detection probe and the outer displacement detection probe.

[0023] In a preferred embodiment of the present invention, in said S3, the method for calculating the actual clearance value G of the gear rack is specifically to detect the displacement data of the gear and the rack using the internal displacement detection probe and the external displacement detection probe adjusted in real time, and perform noise reduction processing on the displacement data;

[0024] The data detected by the internal displacement detection probe and the external displacement detection probe are respectively integrated using the weighted average method to obtain the clearance value of the gear or rack at time t. The actual clearance value G of the gear and rack is obtained by adding the clearance values ​​of the gear and rack at time t, where w t is the weight of the sensor at time t, and dd(t) is the displacement difference at time t.

[0025] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0026] (1) The present invention provides a mechanism for measuring and adjusting the clearance between a gear and rack of an electric steering gear for a passenger car and an adjustment method thereof. The mechanism utilizes the cooperation of an internal displacement detection probe and an external displacement detection probe to detect the displacement of a gear and a rack in motion in real time, thereby ensuring the accuracy of the clearance measurement, calculating the actual clearance value of the gear and rack, and adjusting the clearance to a target clearance value. This ensures high precision and dynamic adjustment, improves system stability, reduces wear, and prolongs service life.

[0027] (2) The present invention constructs a mathematical model to simulate the matching state and offset of the gear and rack of the steering gear in actual state, and controls the detection position of the inner displacement detection probe and the outer displacement detection probe in real time, which can timely reflect the clearance change of the gear rack, improve the accuracy of the detection position of the inner displacement detection probe and the outer displacement detection probe, and at the same time, further improve the accuracy of the clearance measurement.

[0028] (3) The present invention simulates the offset of the gear and rack of the steering gear under actual conditions, calculates the position changes of the inner displacement detection probe and the outer displacement detection probe, and adjusts their positions in real time. The adjusted detection probe data is then integrated and calculated to obtain the actual clearance value of the gear and rack, thereby realizing high-precision, dynamically adjusted clearance measurement and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 is a three-dimensional structural diagram of a preferred embodiment of the present invention;

[0031] Figure 2 is a front view schematic diagram of a preferred embodiment of the present invention;

[0032] Figure 3 It is a preferred embodiment of the present invention Figure 2 The enlarged schematic diagram of point A in the middle;

[0033] Figure 4 It is a flow chart of a method for measuring and adjusting the clearance of a rack and pinion of an electric steering gear of a passenger vehicle according to the present invention;

[0034] In the figure: 1. back plate; 2. internal displacement detection probe; 3. external displacement detection probe; 4. moving plate; 5. first telescopic cylinder; 6. first rotating sleeve; 7. second rotating sleeve; 8. tightening shaft; 9. fixed shaft; 10. rotating block; 11. servo motor; 12. second gear; 13. internal displacement sensor; 14. external displacement sensor. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0037] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, "multiple" means two or more.

[0038] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0039] like Figure 1 and Figure 2 As shown, a gear rack clearance measuring and adjusting mechanism for an electric steering gear of a passenger car comprises: a back plate 1, a telescopic mechanism, an inner displacement detection probe 2, an outer displacement detection probe 3, a tightening mechanism and a control unit. The telescopic mechanism is installed on the side of the back plate 1, and a rotating mechanism is provided on the side of the tightening mechanism. The telescopic mechanism drives the rotating mechanism to move.

[0040] The telescopic mechanism includes: a moving plate 4 and a first telescopic cylinder 5; the moving plate 4 and the back plate 1 slide up and down, and the first telescopic cylinder 5 is fixed to the back plate 1;

[0041] A first rotating sleeve 6 and a second rotating sleeve 7 are fixedly installed on the side of the moving plate 4, and the tightening mechanism includes: a tightening shaft 8, a fixed shaft 9 and a rotating block 10; the end of the rotating block 10 is fixedly installed with the first rotating sleeve 6, the tightening shaft 8 is sleeved in the middle of the fixed shaft 9, and the end of the tightening shaft 8 is rotatably installed with the second rotating sleeve 7, and the inner displacement detection probe 2 passes through the tightening shaft 8, wherein a detection channel is provided at the axial position of the tightening shaft 8 for the telescopic movement of the inner displacement detection probe 2, and the other end of the tightening shaft 8 is provided with a slot adapted to the adjustment position in the steering gear, and the tightening shaft 8 is rotatably connected with the rotating block 10 to provide support for the tightening shaft 8;

[0042] The control unit simulates the actual load state of the steering gear, controls the detection positions of the inner displacement detection probe 2 and the outer displacement detection probe 3, detects the displacement data of the gear and the rack, calculates the actual clearance value between the gear and the rack, controls the operation of the rotating mechanism, and engages the groove of the tightening shaft 8 with the adjusting bolt on the steering gear, driving the adjusting bolt to rotate and move toward the rack direction of the steering gear, and the end of the adjusting bolt on the steering gear contacts the back of the rack, driving the rack to move toward the gear, thereby adjusting the clearance of the gear and the rack in real time.

[0043] It should be noted that in actual use, a two-axis motion system is installed on the side of the back plate 1, specifically, a two-axis motion platform, which controls the back plate 1 to move and position accurately on the X-axis and Z-axis, wherein the direction in which the movable plate 4 slides up and down on the back plate 1 is the Y-axis, and the back plate 1 is relatively installed to the movable plate 4. The installation direction of the back plate 1 (i.e., the direction perpendicular to the back plate) is defined as the Z-axis, and the direction perpendicular to the Y-axis and the Z-axis is the X-axis, thereby controlling the detection position adjustment of the inner displacement detection probe 2 and the outer displacement detection probe 3;

[0044] The actual load state of the steering gear is simulated by the control unit, specifically, the dynamic loading and dynamic unloading between the gear rack and the temperature inside the steering gear, so as to simulate the actual load factors on the gear and the rack under the actual load state, causing the gear rack to deviate from the actual installation position, which is the offset. Based on the offset, the detection positions of the inner displacement detection probe 2 and the outer displacement detection probe 3 are controlled and adjusted, so that the detection positions of the inner displacement detection probe 2 and the outer displacement detection probe 3 are always maintained at the same position, wherein the control unit controls the first telescopic cylinder 5 to drive the moving plate 4 to move in the Y-axis direction, and combines with the back plate 1 to perform precise movement and positioning on the X-axis and Z-axis, so as to drive the inner displacement detection probe 2 and the outer displacement detection probe 3 to accurately enter the detection position, thereby improving the accuracy of detecting the displacement of the gear rack and providing a basis for the subsequent calculation of the actual gap value between the gear rack and the gear.

[0045] Based on the real-time detection of the internal displacement detection probe 2 and the external displacement detection probe 3, the displacement data is obtained and transmitted to the control unit. The control unit obtains the actual gap value between the gear rack by calculation. At the same time, the control unit sets the target gap value, controls the rotating mechanism, and drives the tightening mechanism to adjust the gear rack until the gap between the gear rack reaches the target gap value, thereby completing the precise adjustment of the gear rack gap in the steering gear.

[0046] In the present invention, by simulating the dynamic loading and unloading between the gear rack and the temperature change in the steering gear in actual use, it is avoided that the gear rack with a gap itself is offset in its installation position under the influence of external factors, resulting in the position of the inner displacement detection probe 2 and the outer displacement detection probe 3 being unable to be in the expected detection position, thereby effectively improving the detection accuracy of the inner displacement detection probe 2 and the outer displacement detection probe 3, thereby further improving the accuracy of calculating the gear rack gap;

[0047] At the same time, the internal displacement detection probe 2 and the external displacement detection probe 3 are used to detect the displacement of the rack and the rotation angle of the gear in real time, and combined with the offset that occurs in the matching of the gear and rack, the gap between the gear and rack in actual circumstances is calculated, thereby further improving the accuracy of the gap measurement. The tightening mechanism is used, and the control unit adjusts the number of rotations of the second rotating sleeve 7 according to the actual gap value calculated, thereby adjusting the gap between the gear and rack.

[0048] like Figure 1 , 3 As shown, in the present invention, the rotating mechanism includes: a servo motor 11, a first gear and a second gear; the first gear and the second gear are both located in the second rotating sleeve 7 and are rotatably connected to the second rotating sleeve 7, the first gear and the second gear are meshed, the servo motor 11 is fixed to the moving plate 4, the output end of the servo motor 11 is fixed to the axial position of the first gear, and the end of the tightening shaft 8 is fixed to the axial position of the second gear 12, and the end of the tightening shaft 8 is fixed to the axial position of the second gear 12;

[0049] During the process of adjusting the clearance between the gear rack, the servo motor 11 drives the first gear to rotate, and the second gear meshes with the first gear, driving the second gear to rotate. Since the end of the tightening shaft 8 is fixed at the axial position of the second gear 12, the tightening shaft 8 will be driven to rotate while the second gear rotates. The rotation angle of the output end of the servo motor 11 is related to the clearance value between the gear rack.

[0050] In the present invention, an internal displacement sensor 13 is provided at the end of the internal displacement detection probe 2, and an external displacement sensor 14 is provided at the end of the external displacement detection probe 3. A fixing plate is fixed to the side of the internal displacement sensor 13, and the fixing plate is fixed to the side of the servo motor 11. The external displacement sensor 14 is located on the side of the tightening mechanism and is fixed to the movable plate 4.

[0051] like Figure 4 As shown, a method for measuring and adjusting the clearance of a rack and pinion of an electric steering gear of a passenger car comprises the following steps:

[0052] S1, using the inner displacement detection probe 2 to monitor the displacement of the rack in real time, and the outer displacement detection probe 3 to monitor the rotational displacement of the gear in real time;

[0053] S2. Establish a mathematical model based on the actual load state of the steering gear, wherein the actual load state specifically includes: dynamic loading and dynamic unloading between the gear and the rack, and the temperature inside the steering gear, simulate the offset of the gear and the rack under the actual load state, calculate the position change of the inner displacement detection probe 2 and the outer displacement detection probe 3 through the offset, adjust the inner displacement detection probe 2 and the outer displacement detection probe 3 in real time, so as to accurately obtain the displacement data of the gear and the rack, and transmit the collected data to the control unit;

[0054] Combined with the actual load state, the gap change between the gear rack and the offset between the gear rack in actual use of the steering gear can be simulated, so that the detection position of the inner displacement detection probe 2 and the outer displacement detection probe 3 can be accurately controlled, so that the inner displacement detection probe 2 and the outer displacement detection probe 3 are always in contact with the detection point position in the gear and the rack, ensuring the accuracy of the detection displacement data;

[0055] The inner displacement detection probe 2 and the outer displacement detection probe 3 are adjusted in real time. Specifically, a mathematical model is established by combining dynamic loading, dynamic unloading, and temperature. Where d(t) represents the offset of the rack or gear at time t, F(t) represents the load force acting on the gear or rack at time t, k(t) represents the stiffness coefficient of the gear or rack, which represents the gear's ability to resist deformation, L0 represents the center distance between the gear and the rack in the initial state, which is used as the reference length for calculating thermal expansion, a represents the thermal expansion coefficient of the gear or rack material, which represents the expansion rate of the material with temperature changes, and T t -T represents the difference between the temperature at time t and the reference temperature;

[0056] When the load force F(t) acts on the gear or rack, the gear or rack will produce a certain elastic deformation, and the deformation is The deformation has directionality. When F(t) is a tensile force, it will cause the object (such as a gear or rack) to produce tensile deformation in the direction of the force. Therefore, the direction of the deformation is the same as the direction of the tensile force, and the tensile force is set to a positive value. When F(t) is a pressure, it will cause the object to produce compressive deformation in the direction of the force. Therefore, the direction of the deformation is opposite to the direction of the pressure, and the pressure is set to a negative value.

[0057] T is the reference temperature, which is set to 25°C.

[0058] Set the target value d(0), which is the initial detection position of the inner displacement detection probe 2 or the outer displacement detection probe 3, calculate the offset d(t) and the target value d(0), and get the actual detection position d. Combined with the mathematical formula, we get d(0) represents the initial target position of the rack or gear, and the control unit is used to control the position adjustment of the inner displacement detection probe 2 and the outer displacement detection probe 3;

[0059] By formula Simulate the load and temperature of the gear and rack positions to obtain the offset of the gear and rack in two axes. Based on the offset of the two axes, combined with the formula The two axial offset positions are obtained, specifically, the extended position of the rack is the Z axis, and the relative direction of the rack and the gear is the X axis. The actual detection position can be obtained by combining the two axial offset positions, so that the inner displacement detection probe and the outer displacement detection probe are adjusted in the horizontal position;

[0060] It should be noted that the actual load state, specifically the dynamic loading and dynamic unloading between the gear rack and the temperature inside the steering gear, simulates the actual load factors on the gear and rack under the actual load state. Because these load factors will cause the gear rack to deviate from the actual installation position and cause an offset, the internal displacement detection probe 2 and the external displacement detection probe 3 are actually adjusted in real time.

[0061] S3, preprocessing the displacement data of the gear and rack, integrating the preprocessed real-time data, calculating the displacement difference of the two sensors, and obtaining the actual clearance value G of the gear and rack;

[0062] The method for calculating the actual clearance value G of the gear rack is specifically to use the internal displacement detection probe 2 and the external displacement detection probe 3 that are adjusted in real time to detect the displacement data of the gear and the rack, and perform noise reduction processing on the displacement data;

[0063] The data detected by the internal displacement detection probe and the external displacement detection probe are respectively integrated using the weighted average method to obtain the clearance value of the gear or rack at time t. The actual clearance value G of the gear and rack is obtained by adding the clearance values ​​of the gear and rack at time t, where w t is the weight of the sensor at time t, and dd(t) is the displacement difference at time t.

[0064] S4. Set the target clearance value G of the gear rack based on the actual load state. t The target gap value takes into account the vehicle's operating performance and durability under different load and temperature conditions. The actual gap value G obtained through actual measurement is different from the target gap value G. t Compare and calculate the actual gap value G and the target gap value G t If ΔG is a positive value, the tightening mechanism is controlled to reduce the gear rack clearance. If ΔG is a negative value, the tightening mechanism is controlled to increase the gear rack clearance until the target clearance value G is reached. t ;

[0065] Specifically, the actual gap value calculated in step S3 is compared with the target gap value set in step S4, which is completed by the control unit. The control unit receives the displacement data from the internal displacement detection probe 2 and the external displacement detection probe 3, and calculates the actual gap value. If the actual gap value is greater than the target gap value, that is, the difference is positive, it means that the gear rack gap is too large and the gap needs to be reduced. At this time, the control unit will send an instruction to the tightening mechanism to reduce the gear rack gap mechanically; if the actual gap value is less than the target gap value, that is, the difference is negative, it means that the gear rack gap is too small and the gap needs to be increased. Similarly, the control unit will send an instruction to the tightening mechanism to increase the gear rack gap.

[0066] The control unit continuously monitors the gear rack clearance and sends adjustment instructions to the tightening mechanism when necessary. This process is repeated until the actual clearance value reaches or approaches the target clearance value.

[0067] When the present invention is used, after the steering gear is produced, a hole groove for detecting the displacement of the gear rack is reserved. The actual load state of the steering gear needs to be simulated by the control unit, specifically, the dynamic loading and dynamic unloading between the gear rack and the temperature inside the steering gear, so as to simulate the gear and the rack under the actual load state being affected by the actual load factor, causing the gear rack to deviate from the actual installation position, which is the offset. Based on the offset, the detection positions of the inner displacement detection probe 2 and the outer displacement detection probe 3 are controlled and adjusted, so that the detection positions of the inner displacement detection probe 2 and the outer displacement detection probe 3 are always maintained at the same position, wherein the control unit controls the first telescopic cylinder 5 to drive the moving plate 4 to move in the Y-axis direction, and combines with the back plate 1 to perform precise movement and positioning on the X-axis and Z-axis, so as to drive the inner displacement detection probe 2 and the outer displacement detection probe 3 to accurately enter the detection position;

[0068] Based on the real-time detection of the internal displacement detection probe 2 and the external displacement detection probe 3, the displacement data is obtained and transmitted to the control unit. The control unit obtains the actual gap value between the gear rack by calculation. At the same time, the control unit sets the target gap value and controls the rotating mechanism. The servo motor 11 drives the first gear to rotate, and the second gear meshes with the first gear to drive the second gear to rotate. Since the end of the tightening shaft 8 is fixed at the axial position of the second gear 12, the tightening shaft 8 will be driven to rotate while the second gear rotates. The gear rack is adjusted until the gap between the gear rack reaches the target gap value, thereby completing the precise adjustment of the gear rack gap in the steering gear and ensuring the accuracy of the gear rack gap before the steering gear is put into use.

[0069] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. Passenger car electric steering gear rack and pinion clearance measurement and adjustment mechanism, including: A back plate, a telescopic mechanism, an inner displacement detection probe, an outer displacement detection probe, a tightening mechanism and a control unit, wherein the telescopic mechanism is installed on the side of the back plate, a rotating mechanism is provided on the side of the telescopic mechanism, and drives the rotating mechanism, the inner displacement detection probe and the outer displacement detection probe to move, and a two-axis motion platform is installed on the side of the back plate to control the back plate to move and position accurately on the X-axis and the Z-axis; The telescopic mechanism comprises: a moving plate and a first telescopic cylinder; the moving plate and the back plate slide up and down, and the first telescopic cylinder is fixed to the back plate; The side of the movable plate is fixedly mounted with a first rotating sleeve and a second rotating sleeve, and the tightening mechanism comprises: a tightening shaft, a fixed shaft and a rotating block; the end of the rotating block is fixedly mounted with the first rotating sleeve, the tightening shaft sleeve is arranged in the middle of the fixed shaft, the end of the tightening shaft is rotatably mounted with the second rotating sleeve, the inner displacement detection probe passes through the tightening shaft, and the other end of the tightening shaft is provided with a slot adapted to the adjustment position in the steering gear; The control unit simulates the actual load state of the steering gear, controls the detection positions of the inner displacement detection probe and the outer displacement detection probe, detects the displacement data of the gear and the rack, calculates the actual gap value between the gear and the rack, controls the operation of the rotating mechanism, and adjusts the gap of the gear and the rack in real time.

2. The gear rack clearance measuring and adjusting mechanism for an electric steering gear of a passenger vehicle according to claim 1, characterized in that: The rotating mechanism includes: a servo motor, a first gear and a second gear; the first gear and the second gear are both located in the second rotating sleeve and are rotatably connected to the second rotating sleeve, the first gear and the second gear are meshed, the servo motor is fixed to the movable plate, the output end of the servo motor is fixed to the axial center position of the first gear, and the end of the tightening shaft is fixed to the axial center position of the second gear.

3. The gear rack clearance measuring and adjusting mechanism for an electric steering gear of a passenger vehicle according to claim 1, characterized in that: A detection channel is provided at the axial center of the tightening shaft for the telescopic movement of the inner displacement detection probe.

4. The gear rack clearance measuring and adjusting mechanism for an electric steering gear of a passenger vehicle according to claim 2, characterized in that: An inner displacement sensor is provided at the end of the inner displacement detection probe, and an outer displacement sensor is provided at the end of the outer displacement detection probe. A fixing plate is fixed to the side of the inner displacement sensor, and the fixing plate is fixed to the side of the servo motor. The outer displacement sensor is located on the side of the tightening mechanism and is fixed to the moving plate.

5. The gear rack clearance measuring and adjusting mechanism for an electric steering gear of a passenger vehicle according to claim 1, characterized in that: The external displacement sensor and the internal displacement sensor are both laser sensors.

6. A method for measuring and adjusting the clearance between the rack and pinion of an electric steering gear of a passenger car, based on the mechanism for measuring and adjusting the clearance between the rack and pinion of an electric steering gear of a passenger car according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Use the internal displacement detection probe to monitor the displacement of the rack in real time, and the external displacement detection probe to monitor the rotational displacement of the gear in real time; S2. Establish a mathematical model, simulate the offset of the gear and rack under the actual load state based on the actual load state of the steering gear, calculate the position change of the inner displacement detection probe and the outer displacement detection probe through the offset, adjust the inner displacement detection probe and the outer displacement detection probe in real time, so as to accurately obtain the displacement data of the gear and rack, and transmit the collected data to the control unit; S3, preprocessing the displacement data of the gear and rack, integrating the preprocessed real-time data, respectively calculating the displacement difference of the two sensors, and obtaining the actual clearance value G of the gear and rack; S4. Set the target clearance value G of the rack and pinion based on the actual load state. t , the actual gap value G obtained by actual measurement and the target gap value G t Compare and calculate the actual gap value G and the target gap value G t If ΔG is a positive value, the tightening mechanism is controlled to reduce the gear rack clearance. If ΔG is a negative value, the tightening mechanism is controlled to increase the gear rack clearance until the target clearance value G is reached. t .

7. A method for measuring and adjusting the clearance of a rack and pinion of an electric steering gear of a passenger vehicle according to claim 6, characterized in that: In said S2, the actual load state includes: dynamic loading, dynamic unloading, and temperature; The internal displacement detection probe and the external displacement detection probe are adjusted in real time. Specifically, a mathematical model is established by combining dynamic loading, dynamic unloading, and temperature. Where d(t) represents the offset of the rack or gear at time t, F(t) represents the load force acting on the gear or rack at time t, k(t) represents the stiffness coefficient of the gear or rack, which represents the gear's ability to resist deformation, L0 represents the center distance between the gear and the rack in the initial state, which is used as the reference length for calculating thermal expansion, a represents the thermal expansion coefficient of the gear or rack material, which represents the expansion rate of the material with temperature changes, and T t -T represents the difference between the temperature at time t and the reference temperature; Set the target value d(0), calculate the offset d(t) and the target value d(0), and get the actual detection position d. Combined with the mathematical formula, we get d(0) represents the initial target position of the rack or gear, and the control unit is used to control the position adjustment of the inner displacement detection probe and the outer displacement detection probe.

8. The method for measuring and adjusting the clearance of a rack and pinion of an electric steering gear of a passenger vehicle according to claim 6, characterized in that: In said S3, the method for calculating the actual clearance value G of the gear rack is specifically to detect the displacement data of the gear and the rack by using the internal displacement detection probe and the external displacement detection probe adjusted in real time, and perform noise reduction processing on the displacement data; The data detected by the internal displacement detection probe and the external displacement detection probe are respectively integrated using the weighted average method to obtain the clearance value of the gear or rack at time t. The actual clearance value G of the gear and rack is obtained by adding the clearance values ​​of the gear and rack at time t, where w t is the weight of the sensor at time t, and dd(t) is the displacement difference at time t.

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