CN109677209B

CN109677209B - Control method of drive axle capable of disconnecting half shaft

Info

Publication number: CN109677209B
Application number: CN201710971822.8A
Authority: CN
Inventors: 王占彬; 郑灏; 陈志恒; 邓世林; 谢富科
Original assignee: Zhengzhou Yutong Bus Co Ltd
Current assignee: Yutong Bus Co Ltd
Priority date: 2017-10-18
Filing date: 2017-10-18
Publication date: 2021-05-14
Anticipated expiration: 2037-10-18
Also published as: CN109677209A

Abstract

The invention relates to a control method of a drive axle capable of disconnecting a half shaft. One end of the upstream half shaft is connected with the differential mechanism through a spline, the other end of the upstream half shaft is connected with one end of the downstream half shaft through a bearing, the other end of the downstream half shaft is connected with the wheel hub, and torque force is transmitted between the upstream half shaft and the corresponding downstream half shaft through electromagnetic force. The input current of the winding coil is controlled by a controller, and the magnitude of the current output to the coil by the controller is adjusted according to the opening degree signal of an accelerator pedal; the adjustment principle is as follows: the larger the accelerator pedal opening, the larger the current, and the smaller the accelerator pedal opening, the smaller the current. The invention realizes the controllable breaking of the half shaft of the drive axle, can automatically adjust the opening and closing and connecting force of the half shaft according to the working condition of the whole vehicle, has no contact abrasion, stable performance, long service life, no need of timing maintenance, safety and reliability because of adopting the mode of electromagnetic acting force.

Description

Control method of drive axle capable of disconnecting half shaft

Technical Field

The invention relates to a control method of a drive axle capable of disconnecting a half shaft, belonging to the technical field of vehicles.

Background

The drive axle is located at the tail end of the automobile transmission system and mainly comprises a main speed reducer, a differential mechanism, a half shaft, a drive axle housing and the like. The whole drive axle is connected with the frame through the suspension, the power of the engine is transmitted to the main speed reducer through the transmission shaft, and further transmitted to the half shafts at two ends through the differential mechanism, and transmitted to the tire through the half shafts to drive the whole vehicle to run. The differential mechanism can enable the rotating speeds of the left wheel and the right wheel to be asynchronous, and the functions of steering and the like are met.

At present, the drive axle installed on various motor vehicles cannot be cut off in the torque transmission path, and the mode can cause two problems: one is that when the vehicle is running and does not need power traction (such as sliding and braking, etc. do not need the engine to output power), the kinetic energy of the vehicle is consumed because all the dragging and the non-effective linkage parts can not be cut off, and then the energy is consumed, which leads to the increase of the oil consumption of the whole vehicle. The other type is that the components such as the main reducing gear of the drive axle, the differential mechanism, the half shaft and the like are rigidly connected in the direction of a torque transmission path, so that impact excitation of a road surface is transmitted to the half shaft through a tire and is transmitted to the differential mechanism and the main reducing gear by the half shaft, so that the impact excitation of the uneven road surface acts on the meshing process of the main reducing gear, the problem of large meshing noise of the main reducing gear is caused, and the problem of accelerated wear is also caused.

Chinese patent publication No. CN101780766A discloses a half-shaft clutch of a drive axle, whose working principle is consistent with a clutch installed between a transmission case and an engine flywheel, i.e. the half-shaft of the drive axle is controlled to be disconnected and combined by the separation and combination of two friction discs, thereby realizing the disconnection of the drive axle in the torque direction, however, the clutch designed by the patent has the disadvantages of complicated structure (requiring a separation bearing, a power-assisted operating mechanism, etc.), large required space, difficult arrangement (the half-shaft is located in the axle case, the circumferential space is limited), easy wear loss of the friction discs, difficult replacement, etc., and at the same time, the invention only realizes the simple functions of disconnection and combination.

Chinese patent publication No. CN105003620A discloses a built-in mesh type automobile differential with a vibration damping structure, wherein the differential is provided with a plurality of vibration damping structures distributed along the circumferential direction of a journal on the outer circumferential surface of the journal of a half shaft, and the vibration of the half shaft and the differential is converted into friction heat energy to be consumed through the vibration between a rubber ring and a mass ring in the vibration damping structures, so as to achieve the purpose of vibration damping. However, the vibration damping structure can only effectively damp vibration under a certain resonant frequency, the vibration damping effect under other frequencies is not obvious, and the vibration damping function of the vibration damping structure is almost ineffective against broadband vibration generated by random pavement excitation. Meanwhile, rubber is easy to age, so that the reliability of a vibration damping structure and the stability of vibration damping performance are poor.

Disclosure of Invention

The invention aims to provide a drive axle with a disconnectable half shaft and a control method thereof, which are used for solving the problem that no drive axle which is reliable, stable and small in occupied space and can buffer the impact of a road surface on an axle gear mechanism exists in the prior art.

In order to achieve the above object, the scheme of the invention comprises:

the invention discloses a drive axle capable of disconnecting a half shaft, which comprises a differential mechanism, the half shaft and a wheel hub, wherein the half shaft is used for connecting the differential mechanism and the corresponding wheel hub, the half shaft is divided into a first half shaft and a second half shaft, the first half shaft and the second half shaft are provided with a corresponding outer peripheral surface and an inner peripheral surface at the position close to each other, the first half shaft is provided with a magnetic pole on the outer peripheral surface, and the second half shaft is provided with an electromagnet which is used for attracting the corresponding magnetic pole after being electrified on the inner peripheral surface.

The drive axle half shaft capable of being disconnected has the advantages that the half shaft is disconnected and the half shaft is combined based on electromagnetic force by the aid of the magnetic mechanism, disconnection of the half shaft is achieved, impact from wheels and uneven ground is effectively relieved, friction and consumption parts do not exist, and operation and maintenance cost is reduced.

Further, the device further comprises a controller, and the controller is connected with the electromagnet through the electric brush.

The electromagnet is controlled by the controller, and the controller inputs current to the electromagnet, so that the electromagnet generates electromagnetic force on the permanent magnet, the connection and power transmission of the half shaft are realized, the structure is simple, the reliability is realized, and the occupied space is small.

Further, the first half shaft is an upstream half shaft, and the upstream half shaft is connected with a differential mechanism; the second half shaft is a downstream half shaft, and the downstream half shaft is connected with a hub.

Further, the magnetic pole is a permanent magnet.

Further, the magnetic poles are evenly spaced on the inner circumferential surface, and N poles and S poles are alternately arranged.

Furthermore, the upstream half shaft and the downstream half shaft are connected through a bearing sleeved on the upstream half shaft.

The axle half shaft can be disconnected and connected through the bearing, so that the axle half shaft structure is more stable.

The method for controlling the drive axle capable of disconnecting the half shaft comprises the following steps:

1) collecting an opening signal of an accelerator pedal;

2) adjusting the current output to the coil by the controller according to the opening degree signal of the accelerator pedal; the adjustment principle is as follows: the larger the accelerator pedal opening, the larger the current, the smaller the accelerator pedal opening, and the smaller the current.

When the vehicle is driven, the electromagnetic force of the half shaft is combined according to the required power, so that the impact of the vibration of the tire and the uneven road surface on the transmission system is further alleviated, the meshing noise of gears in the transmission system is reduced, and the abrasion is reduced.

Further, the step 1) also collects a brake pedal signal; the step 2) further comprises the following steps: when a brake pedal signal is available and the opening degree signal of the accelerator pedal is minimum, the controller outputs the maximum current to the coil.

When the vehicle brakes, the half shaft is combined through the maximum electromagnetic force, the braking effect of the engine is effectively utilized, the braking distance is shortened, the loss of a braking system is reduced, and the driving safety is improved.

Further, the step 2) further comprises: when the brake pedal signal is not available and the opening degree signal of the accelerator pedal is minimum, the controller stops outputting current to the coil.

When the vehicle slides, the half shaft is automatically disconnected, so that the vehicle does not need to drag a gear structure and a whole set of transmission system in the axle when sliding, the kinetic energy of the vehicle is not consumed, the sliding distance of the vehicle is increased, and the aims of saving oil and energy are further fulfilled.

Drawings

FIG. 1 is a schematic diagram of a disconnectable axle shaft;

FIG. 2 is a cross-sectional view of a breakable axle connection;

FIG. 3 is a cross-sectional end view of the upstream axle shaft connection;

FIG. 4 is a cross-sectional end view of the downstream axle shaft connection;

FIG. 5 is a radial cross-sectional view of the breakable half-shaft connection;

FIG. 6 is a flowchart of a disconnectable drive axle control method.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

A structure diagram of a drive axle with a disconnectable half shaft as shown in FIG. 1 comprises a power transmission structure a and a disconnectable half shaft b; the power transmission structure a comprises a differential mechanism, a main reduction gear and other power transmission components. The cross-sectional view of a breakable half shaft shown in fig. 2 comprises an upstream half shaft 1, an axle housing 2, a controller 3, a battery pack 4, a wire harness 5, a downstream half shaft 6, a permanent magnet 7, a winding coil 8 and a bearing 9, wherein the upstream half shaft 1 is connected with a differential through splines and receives power torque transmitted downstream through the differential, the other end of the upstream half shaft is connected with the circumferential inner surface of the downstream half shaft 6 through the bearing 9 sleeved on the upstream half shaft, and the upstream half shaft 1 and the downstream half shaft 6 can freely rotate around the axes of the two shafts. As shown in fig. 4, a bearing outer seat 61 is arranged at the end of the joint of the downstream half shaft 6 for axially positioning and fixing the bearing 9, and at the same time, mounting grooves 62 are uniformly arranged in the inner side in the circumferential direction, the winding coil 8 is mounted and fixed on the mounting grooves 62, and the other end of the downstream half shaft 6 is connected with the hub; as shown in fig. 3, permanent magnet slots 12 are provided in the corresponding positions on the upstream half shaft 1 corresponding to the winding coils 8, the permanent magnets 7 are installed and fixed in the permanent magnet slots 12, the permanent magnets 12 and the winding coils 8 are in the same number and are in one-to-one correspondence, and a certain radial gap exists between the permanent magnets 12 and the winding coils 8; meanwhile, when the permanent magnets 7 and the corresponding winding coils 8 are installed, the magnetic poles are opposite (namely, opposite attraction relation is kept), the adjacent permanent magnets 7 and the adjacent winding coils 8 have opposite magnetic poles in the circumferential direction, and the upstream half shaft 1 is provided with a bearing inner seat 11 for installing and fixing the inner ring of the bearing 9. Control circuit comprises controller 3, group battery 4, pencil 5, controller 3 CAN install in on the axle housing 2, controller 3 with group battery 4 links to each other, group battery 4 CAN be independent axle control battery group, also CAN be for whole car battery or other power, controller 3 links to each other with winding coil 8, controls the electromagnetic force size through the electric current size of control input winding coil, controller 3 links to each other with the CAN bus, CAN follow information such as accelerator pedal, brake pedal's aperture in the CAN network. When the whole vehicle runs, the torque of the engine is transmitted to the upstream half shaft 1 through the main reduction gear and the differential gear, then acts on the downstream half shaft 6 from the upstream half shaft 1 through electromagnetic force, finally the torque is transmitted to the hub to drive the whole vehicle to run, and the running condition of the whole vehicle is analyzed and judged through the controller 3 in the process, so that the current is controlled, the disconnection of the disconnectable half shaft b and the connection in different degrees are realized, the energy conservation and the vibration attenuation are realized, and the comfort of the whole vehicle is improved.

As shown in fig. 6, the method for controlling a disconnectable half-axle drive axle determines the operating condition of the entire vehicle by processing and analyzing the opening and closing degree signal of the accelerator pedal and the brake pedal signal, and performs corresponding axle control according to different operating conditions. Specifically, when the controller 3 reads a trigger signal or an opening signal of a brake pedal and the accelerator pedal has no trigger signal or the opening signal is minimum, the whole vehicle is judged to work under a braking condition, the controller 3 outputs maximum current to the coil winding 8 through the wire harness 5 aiming at the braking condition, so that the upstream half shaft and the downstream half shaft are in a maximum electromagnetic force connection state, at the moment, the hub drags the upstream parts of a transmission system such as a transmission shaft, a gearbox and an engine main shaft through the half shafts, the braking effect of the engine acts on wheels, the braking performance of the whole vehicle is ensured, and the brake system is prevented from being overheated. When the brake pedal and the accelerator pedal are both free of trigger signals or opening signals, the controller 3 judges that the whole vehicle works in a sliding working condition, the controller 3 cuts off current leading to the coil winding 8 aiming at the sliding working condition of the whole vehicle, and the coil winding 8 and the permanent magnet 7 do not generate acting force, so that the upstream half shaft and the downstream half shaft are in a disconnected state, the phenomenon that a hub reversely drags upstream parts of a transmission system such as a transmission shaft and a gearbox in the sliding process of the whole vehicle is avoided, unnecessary kinetic energy loss is reduced, and the oil saving effect is improved. When the brake pedal is not triggered or the opening signal is generated, and the accelerator opening signal or the accelerator opening signal is larger than the minimum value, the whole vehicle is judged to work in a non-sliding running working condition, aiming at the working condition, the controller 3 controls the current to enable the acting force between the winding coil 8 and the permanent magnet 7 to be adaptive to the resistance or the driving force when the whole vehicle runs, at the moment, an upstream half shaft and a downstream half shaft are mutually connected through nonlinear magnetic force and transmit torque, random impact excitation on the road surface is realized, the impact amplitude acting on the differential mechanism and the main reducing gear is effectively restrained through attenuation of the nonlinear magnetic force, the vibration reduction effect of the road surface impact excitation is realized, the running working condition of the differential mechanism and the main reducing gear is improved, the gear noise is reduced, and the comfort of the whole vehicle is improved.

Meanwhile, due to the adoption of the electromagnetic acting force of the winding coil 8 and the permanent magnet 7, non-contact is realized in the torque transmission process, the friction loss is avoided, the durability and the reliability of the vibration damping structure are improved, and the vibration damping performance has stronger stability due to the fact that the electromagnetic acting force is not aged.

Claims

1. A control method of a drive axle capable of disconnecting half shafts is characterized in that the drive axle capable of disconnecting half shafts comprises a differential mechanism, half shafts, a wheel hub and a controller, wherein the half shafts are used for connecting the differential mechanism and the corresponding wheel hub; the controller is connected with the electromagnet through the electric brush, and the method comprises the following steps:

1) collecting an opening signal of an accelerator pedal;

2) adjusting the current output by the controller to the coil of the electromagnet according to the opening signal of the accelerator pedal; the adjustment principle is as follows: the larger the accelerator pedal opening, the larger the current, the smaller the accelerator pedal opening, and the smaller the current.

2. The control method of a transaxle of a disconnectable half shaft according to claim 1, wherein the step 1) further collects a brake pedal signal; the step 2) further comprises the following steps: when a brake pedal signal is available and the opening degree signal of the accelerator pedal is minimum, the controller outputs the maximum current to the coil of the electromagnet.

3. The method of controlling a transaxle of a disconnectable half shaft according to claim 2, wherein the step 2) further comprises: when no brake pedal signal exists and the opening degree signal of the accelerator pedal is minimum, the controller stops outputting current to the coil of the electromagnet.

4. The method of claim 1, wherein the first axle shaft is an upstream axle shaft connected to a differential; the second half shaft is a downstream half shaft, and the downstream half shaft is connected with a hub.

5. The method for controlling a transaxle of a disconnectable half shaft according to claim 1, wherein the magnet is a permanent magnet.

6. The method of claim 1, wherein the magnetic poles are arranged alternately with N-pole and S-pole at regular intervals on the inner circumferential surface.

7. The method for controlling a transaxle having a disconnectable half shaft of claim 4, wherein the upstream half shaft and the downstream half shaft are connected by a bearing fitted on the upstream half shaft.