Automobile steering detection system and method thereof

Abstract

The invention relates to the field of steering performance testing devices, in particular to an automobile steering detection system and a method thereof.The automobile steering detection system comprises a lead screw, a pressure sensor, a ball nut assembly, a damper, a lubricating oil supply device and a controller, the lead screw is connected with an execution part of a steering gear through the pressure sensor, and the ball nut assembly is arranged on the lead screw in a sleeving mode; when the lead screw performs linear motion, the lead screw rotates around the axis of the lead screw, the damper applies resistance to rotating motion of the ball nut assembly, and the controller adaptively adjusts oil supply parameters of lubricating oil supplied to the lead screw and / or the ball nut assembly by the lubricating oil supply device so as to control the internal friction force within a preset range. The internal friction force of the lead screw and the ball nut assembly is detected and calculated in real time, lubricating oil is adaptively added, and the friction force is actively controlled at a constant level, so that the influence of the change of the friction of the test board on the measurement result is eliminated, and the reading accuracy of the pressure sensor is ensured.

Description

Technical Field

[0001] This invention relates to the field of steering performance testing devices, and more specifically to an automotive steering testing system and method. Background Technology

[0002] During the development and testing of vehicle steer-by-wire systems, it is necessary to use simulation testing equipment to bench test the steering actuator assembly in order to verify whether its performance indicators meet the design goals.

[0003] The existing testing equipment adopts a passive load testing scheme that converts the linear motion of the steering actuator into rotational motion using a lead screw and nut pair, and applies resistance to the rotational motion using dampers such as magnetic powder brakes. This scheme can effectively avoid impact damage caused by the loss of synchronization between the loading system and the steering gear under test.

[0004] However, the ball screw pair generates a lot of frictional heat during high-speed reciprocating motion, which causes the internal friction of the ball nut assembly to rise sharply. This constantly changing friction is superimposed on the simulated resistance provided by the damper and is measured by the pressure sensor, thus seriously affecting the accuracy of the test data. Summary of the Invention

[0005] The purpose of this invention is to provide an automotive steering testing system and method to solve the defects of existing steering gear testing devices, such as uncontrollable friction and poor heat dissipation.

[0006] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: A vehicle steering detection system, comprising: The lead screw is configured to be coaxially connected to the actuator of the steering gear; A pressure sensor is disposed between the lead screw and the actuator of the steering gear; A ball nut assembly, rotatably supported by a frame, is configured to be fitted onto the lead screw and rotate about its own axis when the lead screw performs linear motion; A damper is fixedly supported by a frame, and the rotating part of the damper is coaxially connected to the ball nut assembly. The damper is used to apply resistance to the rotational movement of the ball nut assembly. A lubricating oil supply device for supplying lubricating oil to the lead screw and / or the ball nut assembly; The controller is configured to: receive the pressure signal transmitted by the pressure sensor, calculate the frictional force between the lead screw and the ball nut assembly, and adaptively adjust the oil supply parameters of the lubricating oil supply device in response to the frictional force, so as to control the frictional force within a preset range.

[0007] Furthermore, the ball nut assembly includes: a nut body, a ball return mechanism, a front end cap, and a rear end cap; The ball return device is disposed inside the nut body, and the front end cap and the rear end cap are respectively installed at both ends of the nut body; The lubricating oil supply device includes: an oil pump and an oil inlet cap; The oil supply end cap is configured to replace the front end cap of the ball nut assembly. The oil supply end cap is fixedly connected to the frame, and a rotary seal is provided between the oil supply end cap and the nut body. The oil supply end cap has an oil supply channel inside, and the oil supply channel is connected to the output end of the oil pump. The ball return device has a ball flow channel, at least a portion of which is made of a porous material, and the ball flow channel is connected to the oil supply channel. The oil pump is configured to pressurize lubricating oil into the interior of the ball flow channel through the oil supply channel, so that the lubricating oil permeates through the porous material to the surface of the ball flow channel.

[0008] Furthermore, the lubricating oil supply device also includes an oil tank and an oil return end cap; The oil return end cap is configured to replace the rear end cap of the ball nut assembly, and the oil return end cap is coaxially connected to the rotating part of the damper; The oil return end cap has an oil return channel inside, which is connected to the steel ball channel. The oil return end cap also has an oil return chamber inside, which is configured to allow at least one end of the lead screw to move axially therein. The oil return end cap is also provided with an oil drain hole, and the oil return channel is connected to the oil return chamber through the oil drain hole.

[0009] Furthermore, the lubricating oil supply device also includes an oil collecting sleeve, which is fixedly installed on the frame. The oil collecting sleeve is coaxially surrounding the outside of the oil return end cover, and a rotary seal is provided between the oil collecting sleeve and the oil return end cover. The oil collecting sleeve is configured to collect the lubricating oil discharged from the oil drain hole and connect to the oil tank.

[0010] Furthermore, the lubricating oil supply device also includes a filter, and the oil tank is connected to the input end of the oil pump through the filter.

[0011] Furthermore, the inner wall of the oil return chamber is formed as a tapered guide surface, and the inner diameter of the tapered guide surface gradually increases from the ball nut assembly toward the oil drain hole.

[0012] Furthermore, friction textures are provided on the inner wall of the conical guide surface, which are configured to increase the friction between the conical guide surface and the lubricating oil when the oil return end cap rotates.

[0013] Furthermore, the lead screw has an internal gas flow channel; One end of the gas flow channel is formed as an air inlet, and the air inlet is located at the rotation center of the oil return chamber; The other end of the gas flow channel is formed as an exhaust port, which is configured to always be located outside the ball nut assembly; The exhaust port is connected to an air pump.

[0014] Furthermore, it also includes a temperature sensor configured to detect the temperature of the lead screw and / or the ball nut assembly; The controller is electrically connected to the temperature sensor, the air pump, and the oil pump. The controller is configured to adjust the air flow rate of the air pump and / or the oil flow rate of the oil pump according to the temperature signal detected by the temperature sensor, so as to control the temperature signal within a preset range.

[0015] A vehicle steering detection method, wherein the vehicle steering detection method is executed by the vehicle steering detection system, the vehicle steering detection method comprising the following steps: The steps for friction calibration and control are as follows: the damper is deactivated, the controller receives the pressure signal transmitted by the pressure sensor, the controller calculates the pressure signal as the internal friction force between the lead screw and the ball nut assembly, and in response to the internal friction force, the oil supply parameters of the lubricating oil supply device are adaptively adjusted to control the internal friction force within a preset range. The steps for performing a load test are as follows: the damper is activated to apply resistance, the controller receives a pressure signal from the pressure sensor, and the controller is configured to calculate the actual load borne by the steering actuator by subtracting the internal friction force obtained through the friction calibration and control steps from the pressure signal.

[0016] The advantages of this invention compared to the prior art are: This invention detects and calculates the system's own friction in real time, adaptively increases lubrication, and actively controls the friction at a constant level, thereby eliminating the influence of changes in the test bench's own friction on the measurement results and ensuring the accuracy of the pressure sensor readings. Attached Figure Description

[0017] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0018] Figure 1 This is an overall structural diagram of an embodiment of the present invention; Figure 2 This is a structural diagram of the lead screw, ball nut assembly, and lubricating oil supply device according to an embodiment of the present invention; The labels in the diagram represent the following: 1-Screw; 11-Gas flow channel; 12-Air inlet; 13-Exhaust port; 2-Pressure sensor; 3-Ball nut assembly; 31-Nut body; 32-Ball return device; 33-Steel ball flow channel; 4-Damper; 5-Lubricating oil supply device; 51-Oil pump; 52-Oil supply end cap; 53-Oil tank; 54-Oil return end cap; 541-Oil drain hole; 542-Conical guide surface; 55-Oil collection sleeve; 56-Filter; 6-Air pump. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] refer to Figure 1 The present invention provides an automotive steering detection system, which mainly includes a lead screw 1, a pressure sensor 2, a ball nut assembly 3 and a damper 4. The lead screw 1 is configured to be coaxially connected to the actuator of the steering gear 7 under test. The pressure sensor 2 is disposed between the lead screw 1 and the actuator of the steering gear 7 for real-time monitoring of the axial force transmitted between the two.

[0021] The ball nut assembly 3 is rotatably supported by the bearing housing, so that it cannot generate axial displacement. The lead screw 1 passes through the ball nut assembly 3. When the lead screw 1 performs linear reciprocating motion under the drive of the actuator of the steering gear 7, the ball nut assembly 3 rotates around its own axis.

[0022] The fixed part of the damper 4 is connected to the frame, and its rotating part is coaxially connected to the ball nut assembly 3. The damper 4 is used to apply a controllable rotational resistance to the rotational movement of the ball nut assembly 3. This resistance reacts to the actuator of the steering gear 7 through the ball nut assembly 3 and the lead screw 1, thereby simulating the steering resistance of the wheel.

[0023] refer to Figure 1 and Figure 2 In order to solve the problems of uncontrollable friction and inaccurate test data caused by heat accumulation in such automotive steering detection systems, the automotive steering detection system of this application also includes a lubricating oil supply device 5 and a controller.

[0024] The controller is configured to receive the pressure signal transmitted by the pressure sensor 2 in real time. The controller has a built-in algorithm that can calculate the dynamic friction force between the lead screw 1 and the ball nut assembly 3 in real time based on the pressure signal.

[0025] The controller's built-in algorithm is further configured to: adaptively adjust the oil supply parameters of the lubricating oil supply device 5 in response to the friction force. For example, when the calculated friction force exceeds a preset threshold range, start the oil pump 51 and increase the flow rate or frequency of the oil pump 51; otherwise, turn off the oil pump 51 and reduce the flow rate or frequency of the oil pump 51.

[0026] Alternatively, the controller is configured to receive a pressure signal from the pressure sensor 2 when the damper 4 is not in operation. The controller has a built-in algorithm that can calculate the dynamic friction force between the lead screw 1 and the ball nut assembly 3 based on the pressure signal.

[0027] In this way, the vehicle steering detection system achieves closed-loop control of its internal friction force, ensuring that the internal friction force is always actively controlled within a preset low level range, eliminating the interference of its own friction on the test results, and ensuring the accuracy of the data from pressure sensor 2.

[0028] The specific structure of the lubricating oil supply device 5 will be described in detail below.

[0029] refer to Figure 2 The ball nut assembly 3 includes at least: a nut body 31, a ball return device 32 disposed inside the nut body 31, and a front end cap and a rear end cap respectively installed at both ends of the nut body 31.

[0030] The lubricating oil supply device 5 accordingly includes an oil pump 51 and a specially designed oil supply end cap 52.

[0031] The oil supply end cap 52 is configured to replace the front end cap of the ball nut assembly 3. However, the oil supply end cap 52 is fixedly connected to the frame, and a rotary seal is provided between the oil supply end cap 52 and the nut body 31 to prevent oil leakage at the joint between the moving and stationary parts.

[0032] The oil supply end cap 52 has an oil supply channel inside, which is connected to the output end of the oil pump 51.

[0033] The ball returner 32 of the ball nut assembly 3 has a ball flow channel, at least a portion of which is made of a porous material, such as powder metallurgy sintered metal. The internal pores of the porous material are connected to the oil supply channel of the oil supply end cap 52 through the flow channel structure.

[0034] Based on the above structure, an oil supply assembly is established between the oil pump 51 and the lead screw 1, which starts from the output end of the oil pump 51 and flows in the order of oil supply end cover 52, oil supply channel, ball channel, ball, and lead screw 1. This allows the oil pump 51 to directly supply lubricating oil to the lead screw 1 to change the friction between the lead screw 1 and the ball nut assembly 3.

[0035] The working method of this embodiment is as follows: The controller commands the oil pump 51 to start, and the oil pump 51 pressurizes the lubricating oil. The lubricating oil passes through the oil supply channel of the fixed oil supply end cover 52, through the rotary seal, and enters the interior of the rotating ball returner 32. It is then forced into the pores of the porous material. Under the pressure of the oil pump 51, the lubricating oil permeates through the porous material and seeps out from the surface of the ball flow channel, providing a fresh oil film at the precise position where the ball contacts the raceway, and finally being transferred to the surface of the lead screw 1, achieving efficient and direct lubrication.

[0036] Furthermore, in order to achieve the recycling of lubricating oil, this system also provides a complete oil return assembly.

[0037] The lubricating oil supply device 5 also includes an oil tank 53 and an oil return end cap 54, which is configured to replace the rear end cap of the ball nut assembly 3. The oil return end cap 54 rotates together with the nut body 31 and is coaxially connected to the rotating part of the damper 4.

[0038] The oil return end cap 54 has an oil return channel inside, which is connected to the other end of the ball flow channel. The oil return end cap 54 also has an oil return chamber inside, which is used to collect waste oil and is configured to allow at least one end of the lead screw 1 to move freely axially therein.

[0039] The oil return end cover 54 is also provided with at least one oil drain hole 541. The used lubricating oil flows from the ball flow channel, through the oil return flow channel, and finally enters the oil return chamber and is discharged through the oil drain hole 541.

[0040] In order to collect the lubricating oil discharged from the high-speed rotating oil return end cap 54, the lubricating oil supply device 5 also includes an oil collecting sleeve 55, which is fixedly installed on the frame and coaxially surrounds the outside of the rotating oil return end cap 54. A rotary seal is provided between the oil collecting sleeve 55 and the oil return end cap 54 to prevent lubricating oil leakage.

[0041] The oil collecting sleeve 55 is configured to collect lubricating oil thrown out or flowing out from the oil drain hole 541 and connected to the oil tank 53 through the return oil line at the bottom. The lubricating oil supply device 5 also includes a filter 56, through which the oil tank 53 is connected to the input end of the oil pump 51.

[0042] Based on the above structure, a return oil assembly is established between the ball nut assembly 3 and the oil pump 51, starting from the ball flow channel, along the return oil flow channel, return oil chamber, oil drain hole 541, oil collecting sleeve 55, return oil pipeline, oil tank 53, filter 56 and the input end of the oil pump 51. This allows the lubricating oil to be recycled and achieves self-cleaning during the circulation process, preventing secondary damage caused by wear particles or blockage of porous materials.

[0043] Furthermore, in order to improve the oil discharge efficiency of the oil return end cap 54, the present invention also provides a preferred design for the oil return chamber.

[0044] In a preferred embodiment, the inner wall of the oil return chamber is formed as a tapered guide surface 542, the inner diameter of which gradually increases from the ball nut assembly 3 toward the oil drain hole 541.

[0045] When the oil return end cap 54 rotates at high speed, the lubricating oil adhering to the inner wall of the conical guide surface 542 will generate an axial component force along the inclined conical surface under the action of centrifugal force, and be pushed to the position with the largest inner diameter (i.e., the location of the oil drain hole 541), thereby achieving efficient and automatic oil draining.

[0046] In a more preferred embodiment, to further enhance this centrifugal pump effect, the inner wall of the tapered guide surface 542 is also provided with friction textures (e.g., radial ribs, threads, or knurling).

[0047] The purpose of these friction marks is to increase the friction between the inner wall and the oil, forcing the rotation speed of the lubricating oil to be synchronized with the rotation speed of the return oil end cap 54, thereby increasing the centrifugal force on the lubricating oil and improving the oil discharge efficiency of the conical guide surface 542.

[0048] Furthermore, due to the inevitable generation of a large amount of oil mist and air in the oil return chamber at high speeds, this embodiment provides a centrifugal oil-gas separation component to solve this problem.

[0049] In this embodiment, a gas flow channel 11 is machined inside the lead screw 1. One end of the gas flow channel 11 is formed as an air inlet 12, which is located at the rotation center of the oil return chamber. The other end of the gas flow channel 11 is formed as an exhaust port 13, which is configured to always be located outside the ball nut assembly 3. Furthermore, the exhaust port 13 is connected to a vacuum pump 6.

[0050] The working principle of the oil-gas separator is: The oil return end cap 54 rotates at high speed, and the oil return chamber becomes a centrifugal separator. The heavier liquid lubricating oil is thrown to the outermost inner wall under the action of centrifugal force and discharged through the oil drain hole 541, while the lighter air and oil mist are squeezed and collected at the center of rotation. At this time, the air pump 6 actively extracts the air and oil mist collected at the center from the air inlet 12 through the gas flow channel 11 in the center of the screw 1.

[0051] The beneficial effects of oil-gas separation components are: First, it effectively removes oil mist that interferes with system operation.

[0052] Second, it creates negative pressure in the oil return chamber, which attracts lubricating oil and improves its fluidity and circulation efficiency.

[0053] Furthermore, this application also provides an intelligent thermal management module, which includes a temperature sensor for real-time detection of the temperature of the lead screw 1 or ball nut assembly 3, and the controller is electrically connected to the pressure sensor 2, the temperature sensor, the air pump 6, and the oil pump 51.

[0054] The controller's control logic includes friction control and temperature control.

[0055] Friction control is achieved by actively adjusting the oil supply flow of oil pump 51 when the controller calculates high friction from pressure sensor 2.

[0056] Temperature control involves the controller performing one or two actions to actively cool the device when it receives a high-temperature signal from the temperature sensor. 1. Increase the oil supply to use flowing lubricating oil as the cooling medium.

[0057] Second, increase the air extraction volume to accelerate the circulation of oil mist and air, and improve heat exchange efficiency.

[0058] This coordinated control keeps friction and temperature within a preset range.

[0059] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered as falling within the scope of protection of the embodiments of the present invention.

Claims

1. A vehicle steering detection system, characterized in that, include: The lead screw (1) is configured to be coaxially connected to the actuator of the steering gear (7); A pressure sensor (2) is disposed between the lead screw (1) and the actuator of the steering gear (7); The ball nut assembly (3) is rotatably supported by the frame and is configured to be mounted on the lead screw (1) and rotate about its own axis when the lead screw (1) performs linear motion. The damper (4) is fixedly supported by the frame. The rotating part of the damper (4) is coaxially connected to the ball nut assembly (3). The damper (4) is used to apply resistance to the rotational movement of the ball nut assembly (3). A lubricating oil supply device (5) is used to supply lubricating oil to the lead screw (1) and / or the ball nut assembly (3); The controller is configured to receive the pressure signal transmitted by the pressure sensor (2), calculate the friction force between the lead screw (1) and the ball nut assembly (3), and adaptively adjust the oil supply parameters of the lubricating oil supply device (5) in response to the friction force to control the friction force within a preset range.

2. The vehicle steering detection system according to claim 1, characterized in that, The ball nut assembly (3) includes: a nut body (31), a ball returner (32), a front end cap, and a rear end cap; The ball return device (32) is disposed inside the nut body (31), and the front end cap and the rear end cap are respectively installed at both ends of the nut body (31); The lubricating oil supply device (5) includes: an oil pump (51) and an oil supply end cap (52); The oil supply end cap (52) is configured to replace the front end cap of the ball nut assembly (3). The oil supply end cap (52) is fixedly connected to the frame, and a rotary seal is provided between the oil supply end cap (52) and the nut body (31). The interior of the oil supply end cap (52) has an oil supply channel, which is connected to the output end of the oil pump (51). The ball return device (32) has a ball flow channel (33), at least a portion of which is made of a porous material and is connected to the oil supply channel; The oil pump (51) is configured to pressurize lubricating oil into the interior of the ball flow channel (33) through the oil supply channel, so that the lubricating oil permeates through the porous material to the surface of the ball flow channel (33).

3. The vehicle steering detection system according to claim 2, characterized in that, The lubricating oil supply device (5) also includes an oil tank (53) and an oil return end cap (54). The oil return end cap (54) is configured to replace the rear end cap of the ball nut assembly (3), and the oil return end cap (54) is coaxially connected to the rotating part of the damper (4). The oil return end cap (54) has an oil return channel inside, which is connected to the steel ball channel (33). The oil return end cap (54) also has an oil return chamber inside, which is configured to allow at least one end of the lead screw (1) to move axially therein. The oil return end cap (54) is also provided with an oil drain hole (541), and the oil return channel is connected to the oil return chamber through the oil drain hole (541).

4. The vehicle steering detection system according to claim 3, characterized in that, The lubricating oil supply device (5) further includes an oil collecting sleeve (55), which is fixedly installed on the frame. The oil collecting sleeve (55) is coaxially surrounding the outside of the oil return end cap (54), and a rotary seal is provided between the oil collecting sleeve (55) and the oil return end cap (54). The oil collecting sleeve (55) is configured to collect the lubricating oil discharged from the oil drain hole (541) and connect to the oil tank (53).

5. The vehicle steering detection system according to claim 4, characterized in that, The lubricating oil supply device (5) also includes a filter (56), and the oil tank (53) is connected to the input end of the oil pump (51) through the filter (56).

6. The vehicle steering detection system according to claim 3, characterized in that, The inner wall of the oil return chamber is formed as a tapered guide surface (542), and the inner diameter of the tapered guide surface (542) gradually increases from the ball nut assembly (3) toward the oil drain hole (541).

7. The vehicle steering detection system according to claim 6, characterized in that, The inner wall of the conical guide surface (542) is provided with friction textures, which are configured to increase the friction between the conical guide surface (542) and the lubricating oil when the oil return end cap (54) rotates.

8. The vehicle steering detection system according to claim 3, characterized in that, The lead screw (1) has a gas flow channel (11) inside. One end of the gas flow channel (11) is formed as an air inlet (12), and the air inlet (12) is located at the rotation center of the oil return chamber; The other end of the gas flow channel (11) is formed as an exhaust port (13), which is configured to always be located outside the ball nut assembly (3); The exhaust port (13) is connected to an air pump (6).

9. The vehicle steering detection system according to claim 8, characterized in that, It also includes a temperature sensor configured to detect the temperature of the lead screw (1) and / or the ball nut assembly (3); The controller is electrically connected to the temperature sensor, the air pump (6) and the oil pump (51). The controller is configured to adjust the air flow rate of the air pump (6) and / or the oil flow rate of the oil pump (51) according to the temperature signal detected by the temperature sensor, so as to control the temperature signal within a preset range.

10. A method for detecting vehicle steering, characterized in that, The vehicle steering detection method is executed by the vehicle steering detection system as described in claim 1, and the vehicle steering detection method includes the following steps: The steps for friction calibration and control are as follows: the damper (4) is not working, the controller receives the pressure signal transmitted by the pressure sensor (2), the controller calculates the pressure signal as the internal friction force between the lead screw (1) and the ball nut assembly (3), and in response to the internal friction force, the oil supply parameters of the lubricating oil supply device (5) are adjusted adaptively to control the internal friction force within a preset range. The steps for performing a load test are as follows: the damper (4) is activated to apply resistance, the controller receives the pressure signal transmitted by the pressure sensor (2), and the controller is configured to calculate the actual load borne by the steering gear (7) actuator by subtracting the internal friction force obtained through the friction calibration and control steps from the pressure signal.

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