WO2021174496A1

WO2021174496A1 - Magnetorheological fluid retarder and control method therefor

Info

Publication number: WO2021174496A1
Application number: PCT/CN2020/078033
Authority: WO
Inventors: 任峰; 蒋正英
Original assignee: 任峰
Priority date: 2020-03-02
Filing date: 2020-03-05
Publication date: 2021-09-10
Also published as: CN111207164A; CN111207164B

Abstract

Disclosed are a magnetorheological fluid retarder and a control method therefor. Valve characteristics of a magnetorheological fluid are utilized, and a high back pressure is generated by using a valve, such that braking is conducted, the braking torque is large, the response is fast, and the safety of a braking system is greatly improved. When braking is not required, the retarder does not work, and no magnet exciting coils are powered on; and when braking is required and the retarder receives a retarding braking signal, a magnet exciting coil module is powered on, the current is gradually increased, an oil port is gradually closed, and the back pressure in the retarder is gradually increased, thereby gradually increasing a braking force so as to achieve a retarding effect.

Description

Magnetorheological fluid retarder and its control method

Technical field

The invention relates to the field of vehicle auxiliary braking, in particular to a magnetorheological fluid retarder device and a control method thereof.

Background technique

Commercial vehicles have developed in the direction of high speed and heavy load in recent years. With the rapid increase in vehicle dynamics and faster driving speeds, the braking load of vehicles has also increased, especially for buses operating in cities. For long-distance buses, trucks and other medium and heavy vehicles that run on mountain roads for a long time, they often encounter working conditions of downhill and long slopes, which cause the problem of vehicle braking load to be even more prominent. If these braking loads are all borne by the vehicle's own braking system, not only may the braking performance be reduced, but also the brake drum and brake pads may overheat due to frequent braking, which may cause the vehicle to deviate and lose stability. And a series of accidents such as rear-end collision. Therefore, the installation of auxiliary braking devices to divert the load of the wheel brakes and control the temperature of the wheel brakes within a safe range has become the development direction of the vehicle brake system. At present, the auxiliary brakes used in vehicles mainly include hydraulic retarders, eddy current retarders and magnetorheological disc retarders. The hydraulic retarder has a complex structure, high cost, slow response and high fuel consumption. The eddy current retarder generally works after the vehicle speed is reached, and it reaches the maximum on the left and right, and the speed space for auxiliary braking is limited. In addition, the eddy current retarder relies on electric braking, which requires a large amount of electric energy, and the required current is up to Hundreds of amperes, and even the need to install a battery, will affect the service life of the battery and the engine. The magnetorheological disc retarder still uses the shear and squeezing force of the magnetorheological fluid to generate resistance, or rely on friction to generate resistance. Resistance, the generated braking force is relatively limited, and at the same time, wear occurs, which brings about problems such as difficulty in solving heat dissipation problems. Therefore, these problems have high cost and difficulty in popularization in batch use.

Compared with the traditional hydraulic retarder, the magnetorheological fluid retarder involved in the present invention does not need to discharge or feed the medium in the working chamber, saves the special oil storage cavity and oil supply system, and directly uses the magnetorheological fluid Features to achieve braking.

Compared with the conventional magnetorheological fluid retarder braking principle, it does not simply use the shear stress and extrusion stress of the magnetorheological fluid, but uses the valve characteristics of the magnetorheological fluid and applies the valve magnetorheological fluid. The hydraulic properties produce a high back pressure in the retarder, thereby generating a braking force to achieve slow braking.

Summary of the invention

In order to solve the above problems, the present invention provides a new type of magnetorheological fluid retarder, which has the characteristics of small structure, low energy consumption, large braking torque, fast response, low cost, and mass production.

In order to achieve the above objectives, the present invention adopts the following technical solutions:

A magnetorheological fluid retarder, comprising a main casing (8), an inner rotor (15), an outer rotor (14), a left casing (4), a heat exchanger (9), a sealing part and a flow distribution channel The main housing (8) is provided with an outer rotor (14) and an inner rotor (15) in sequence, and the shaft (1) is arranged through the inner rotor (15); the left housing (4) is arranged in the main housing (8) On the left side, the left shell (4) is provided with a flow distribution channel; the heat exchanger (9) is arranged on the right side of the main shell (8); it is characterized by:

The distribution passage includes a high-pressure oil passage (21) and a low-pressure oil passage (5); the fuel filler port (7) is connected with the high-pressure oil passage (21), and the low-pressure oil passage (5) is connected with the oil discharge port (6); the high-pressure oil passage (21) is provided with a high-pressure oil port (28), and a low-pressure oil port (26) is provided in the low-pressure oil passage (5); the high-pressure oil port (28) and the low-pressure oil port (26) are connected through the flow passage; the high-pressure oil A first excitation coil module (27) is installed in the port (28), a second excitation coil module (29) is installed in the low-pressure oil port (28), and a third excitation coil module (30) is installed in the overcurrent channel And the fourth excitation coil module (31).

Preferably, the sealing part includes a first sealing ring (16) arranged inside the left housing (4), a second sealing ring (20) arranged inside the main housing (8), and an oil seal (20) arranged outside the shaft. 2).

Preferably, the retarder further includes a first bushing (13) and a second bushing (19) arranged on the outside of the shaft.

Preferably, the retarder further includes a cooling liquid inlet (32) and a cooling liquid outlet (33).

Preferably, the excitation coil module includes an excitation coil for providing excitation to the magnetorheological fluid; and an inner flow channel for the magnetic fluid to pass through.

Preferably, the inner flow channel is a single-hole flow channel or a multi-hole flow channel.

Preferably, a magnetorheological fluid retarder control system has the magnetorheological fluid retarder mentioned above; the control system also has a retarder controller for controlling the retarder; When arranged in parallel, the retarder shaft and the retarder input shaft gear are connected in a torsion-resistant manner, and the retarder input shaft gear is meshed with the gear of the gearbox output shaft; when arranged in series, the front end of the retarder shaft is connected to the transmission through a flange The output shaft of the box is connected, and the output of the retarder is connected with the transmission shaft. The torque of the retarder shaft is controlled to realize the control of the braking torque of the vehicle.

Preferably, a control method of a magnetorheological fluid retarder, when braking is not required, the retarder does not work, all excitation coils are not energized, and the shaft (1) of the retarder drives the inner rotor (15) When rotating, the inner rotor (15) meshes with the outer rotor (14) to make free rotation movement, and the retarder does not generate retarding braking force;

When braking is required, when the retarder receives the retarding braking signal, the third excitation coil module (30) is energized, the viscosity of the magnetorheological fluid gradually increases, the damping gradually increases, and the flow channel is blocked. The high-voltage and low-voltage areas are disconnected; the first excitation coil module (27) is energized, the current increases from small to large, the high-voltage port (28) gradually closes, and the internal back pressure of the retarder gradually increases, resulting in a gradual braking force Increase to achieve slow speed effect;

When the vehicle is driving in the reverse direction, the fourth excitation coil module (31) is energized, the viscosity of the magnetorheological fluid gradually increases, and the damping gradually increases, and the overcurrent channel is blocked to disconnect the high and low pressure areas; the second excitation coil The module (29) is energized, the current increases from small to large, the low-pressure oil port (26) is gradually closed, and the internal back pressure of the retarder gradually increases, which in turn causes the braking force to gradually increase to achieve the retarding effect.

The invention utilizes the characteristics of the magnetorheological fluid valve and applies the valve to generate high back pressure to perform braking. The braking principle has no friction, large braking torque, fast response (millisecond order), and greatly improves braking. The security of the system.

Advantages of this retarder:

1. The slow braking torque changes continuously, that is, the continuous change of the slow braking torque can be controlled according to the continuous change of the current.

2. Using the effect of magnetorheology to control, the energy consumption of control is relatively low.

3. The response time of magnetorheology from Newtonian fluid to viscoelastic solid is relatively sensitive, which is millimeter level.

4. It has better low-speed performance than conventional retarders, because traditional hydraulic retarders have poor braking torque at low speeds.

5. The retarder braking system of this patent can be continuously and quickly controlled, and the sensor can match the changes of vehicle working conditions to achieve accurate, fast, and high-quality retarder braking without pressure pulsation, and the retarder Greatly reduce costs.

6. By adding an energy recovery system, the vehicle can be braked through the recovered braking energy when the power supply of the whole vehicle fails.

7. This solution can be arranged at the input end of the transmission, the output end of the transmission, and the input end of the drive axle as required; the magnetorheological retarder can be installed in series or parallel with the input end of the transmission, or can be installed in series or parallel with the output end of the transmission. It can also be connected in series or in parallel with the input end of the rear axle. The present invention is described by taking the parallel installation at the output end of the transmission as an example.

When arranged in parallel, the retarder shaft and the retarder input shaft gear are connected in a torsion-resistant manner, and the retarder input shaft gear is meshed with the gear of the gearbox output shaft; when arranged in series, the front end of the retarder shaft is connected to the transmission through a flange The output shaft of the box is connected, and the output of the retarder is connected with the drive shaft.

Description of the drawings

Figure 1 is a schematic diagram of the control principle of the magnetorheological retarder control system of the present invention;

2 is a schematic diagram of the structure of the magnetorheological retarder in the first embodiment of the present invention;

3 is a schematic cross-sectional view of the main housing in the first embodiment of the present invention;

4 is a schematic diagram of a radial cross-section of the left housing in the first embodiment of the present invention;

Figure 5 is a diagram of the magnetorheological fluid channel and control principle in the first embodiment of the present invention;

[Cited and added (Rules 20.6) 24.03.2020]
Fig. 6 is a schematic diagram of a magnetorheological fluid retarder in the fourth embodiment of the present invention;

Description of Reference Signs

Main housing 8, outer rotor 14, inner rotor 15, left housing 4, shaft 1, oil seal 2, bearing 3, low-pressure oil passage 5, high-pressure oil passage 21, oil outlet 6, oil filler 7, heat exchanger 9 , Heat exchanger screw 10, bearing end cover 11, bearing end cover screw 12, first bushing 13, first sealing ring 16, bearing 17, oil seal 18, second bushing 19, second sealing ring 20, connecting bolt 22. High and low pressure oil port passage 23, low pressure distribution oil passage 24, high pressure distribution oil passage 25, low pressure oil port 26, first excitation coil module 27, high pressure oil port 28, second excitation coil module 29, third excitation The coil module 30, the fourth excitation coil module 31, the coolant inlet 32, and the coolant outlet 33.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

In the description of the present invention, it needs to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", " The orientation or positional relationship indicated by "outside" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation and The specific azimuth structure and operation cannot be understood as a limitation of the present invention.

Example one:

The shaft 1 is supported by the bearing 3 and the bearing 17. The left side of the bearing is sealed by the oil seal 2 and the right side is positioned by the bushing 13. The heat exchanger 9 is connected with the main housing 8 by the screw 10, and the left side of the bearing 17 is passed by the bushing. The sleeve 19 and the bearing end cover 11 are positioned and sealed by an oil seal 18, and the bearing end cover 11 is connected to the main housing 8 by screws 12.

When the retarder controller receives the retarder braking command from the vehicle controller, the retarder controller sends an instruction to control the retarder to perform retarder braking.

When the retarder is not working, the high-pressure port and the low-pressure port of the retarder are connected through the high and low pressure oil passages, all the excitation coils are not energized, the input shaft of the retarder drives the inner rotor to rotate, and the inner rotor and the outer rotor mesh for free rotation. The speed controller does not produce retarding braking force.

When the retarder receives the retarder braking signal, the third excitation coil module 30 is energized, and the magnetorheological fluid gradually changes from liquid to solid, completely sealing the high and low pressure oil passages, and disconnecting the high and low pressure areas; An excitation coil module 27 is energized and controlled by the retarder controller. The current is increased from small to large, and the high-pressure oil port 28 is gradually closed, which causes the internal back pressure of the retarder to increase, which in turn causes the braking force to gradually increase until the high-pressure port Completely closed, the slow braking force reaches its maximum.

When the vehicle is driving in the reverse direction, the fourth excitation coil module 31 is energized to completely seal the high and low pressure oil passages, and the high and low voltage areas are disconnected; the second excitation coil module 29 is energized and is controlled by the retarder controller. From small to large, the magnetorheological fluid gradually changes from liquid to solid, and the low-pressure oil port 26 is gradually closed, which causes the internal back pressure of the retarder to increase, which in turn causes the braking force to gradually increase until the low-pressure oil port 26 is completely closed. The speed of the brake is maximized.

During operation, the magnetorheological fluid circulates through the heat exchanger 9, and the vehicle coolant circulates through the inlet 32 of the heat exchanger 9 and then circulates through the outlet 33 to dissipate the heat generated by the retarder.

The heat dissipation can use the vehicle's own heat dissipation system for heat dissipation, or an independent heat dissipation system can be set up by adding a radiator, a cooling fan, a circulating water pump, a heat dissipation motor, and opening a heat dissipation water circulation channel on the retarder shell, depending on the heat balance. Make flexible arrangements.

The inner rotor 15 of the retarder meshes with the outer rotor 14. The inner rotor is installed on the shaft 1 through torsion splines to ensure that sufficient torque can be transmitted; when the retarder brakes, the shaft drives the inner rotor to rotate, and the inner rotor drives the outer rotor Rotate in the main housing 8. The left housing 4 and the main housing 8 are connected together. The positioning is performed by the positioning stop and the cylindrical pin, and the bolts are used for connection to ensure that the eccentricity of the main housing 8 and the inner and outer rotors is accurate. The left housing 4 has a flow distribution channel. , Forming a flow distribution mechanism, so that the inner rotor, outer rotor, and left housing form a low-pressure cavity and a high-pressure cavity. The low-pressure cavity communicates with the low-pressure oil port through the oil passage, and the high-pressure cavity communicates with the high-pressure oil port; the high-pressure oil port and refueling Port 7 communicates, low-pressure oil port communicates with oil discharge port 6; at the same time, the high-pressure oil port and low-pressure oil port are connected through the oil passage.

Example two

On the basis of the structure of the above embodiment, the retarder can not only adopt an internal meshing rotor, but also an external meshing rotor, a one-shaft screw pump rotor, a two-shaft spiral rotor magnetorheological fluid retarder, and a three-shaft spiral rotor. Magnetorheological fluid retarder, etc.

Example three

On the basis of the above-mentioned embodiment, the channel in the excitation coil module has a single-hole or porous structure, and the outside of the excitation coil is magnetically isolated to prevent external interference. The inside of the coil is made of high-permeability materials to make full use of the magnetic field.

Example four

As shown in Figure 6: In order to further improve the heat dissipation performance of the retarding brake system, a blower is added, which can be a centrifugal blower, an axial blower, and other types of blowers. In this embodiment, an axial flow blower is taken as an example. The axial flow blower 35 is connected to the shaft 1 through an electromagnetic clutch 34. 36 is the blower air inlet, 37 is the blower impeller, 38 is the blower guide vane, 39 is the blower diffuser, and 40 is the blower air outlet.

A temperature sensor is installed on the retarder. When the temperature of the retarder exceeds the required heat dissipation temperature, the inductive switch is turned on, the circuit is turned on, the electromagnetic clutch is connected, and the blower 35 starts to work. When the retarder temperature is lower than the required heat dissipation temperature, the induction switch is disconnected, the electromagnetic clutch is disconnected, and the blower 35 stops working.

The blower outlet 40 radiates heat to the retarder housing, and the radiated wind is discharged through the vent.

Claims

A magnetorheological fluid retarder, comprising a main casing (8), an inner rotor (15), an outer rotor (14), a left casing (4), a heat exchanger (9), a sealing part and a flow distribution channel The main housing (8) is provided with an outer rotor (14) and an inner rotor (15) in sequence, and the shaft (1) is arranged through the inner rotor (15); the left housing (4) is arranged in the main housing (8) On the left side, the left shell (4) is provided with a flow distribution channel; the heat exchanger (9) is arranged on the right side of the main shell (8); it is characterized by:

The distribution channel includes a high-pressure oil passage (21) and a low-pressure oil passage (5); the fuel filler (7) is connected with the high-pressure oil passage (21), and the low-pressure oil passage (5) is connected with the oil discharge port (6); the high-pressure oil passage (21) is provided with a high-pressure oil port (28), and a low-pressure oil port (26) is provided in the low-pressure oil passage (5); the high-pressure oil port (28) and the low-pressure oil port (26) are connected through the flow passage; the high-pressure oil A first excitation coil module (27) is installed in the port (28), a second excitation coil module (29) is installed in the low-pressure oil port (28), and a third excitation coil module (30) is installed in the overcurrent channel And the fourth excitation coil module (31).
A magnetorheological fluid retarder according to claim 1, characterized in that:

The sealing part includes a first sealing ring (16) arranged inside the left housing (4), a second sealing ring (20) arranged inside the main housing (8), and an oil seal (2) arranged outside the shaft.
A magnetorheological fluid retarder according to claim 1, characterized in that:

The retarder also includes a first bush (13) and a second bush (19) arranged on the outside of the shaft.
A magnetorheological fluid retarder according to claim 1, characterized in that:

The retarder also includes a cooling liquid inlet (32) and a cooling liquid outlet (33).
A magnetorheological fluid retarder according to claim 1, characterized in that: the excitation coil module includes an excitation coil used to provide excitation to the magnetorheological fluid; Runner.
A magnetorheological fluid retarder according to claim 5, characterized in that:

The internal flow channel is a single-hole flow channel or a multi-hole flow channel.
A magnetorheological fluid retarder control system, which has any magnetorheological fluid retarder according to claims 1-6, characterized in that:

The control system also has a retarder controller for energizing the excitation coil module; the shaft (1) is connected with the output shaft of the gearbox through a gear; and the output speed of the gearbox is controlled by controlling the damping of the retarder.
A method for controlling any magnetorheological fluid retarder according to claims 1-6, characterized in that:

When braking is not required, the retarder does not work, all excitation coils are not energized, the shaft (1) of the retarder drives the inner rotor (15) to rotate, and the inner rotor (15) meshes with the outer rotor (14) for freedom The retarder does not generate retarding braking force when it rotates; when the retarder receives the retarding braking signal, the third excitation coil module (30) is energized, and the viscosity of the magnetorheological fluid gradually increases. , The damping is gradually increased, and the overcurrent channel is blocked to realize the disconnection of the high voltage and low voltage areas; the first excitation coil module (27) is energized, the current is increased from small to large, the high-pressure oil port (28) is gradually closed, and the inside of the retarder The back pressure gradually increases, which in turn leads to a gradual increase in braking force, achieving a slow-down effect;

When the vehicle is driving in the reverse direction, the fourth excitation coil module (31) is energized, the viscosity of the magnetorheological fluid gradually increases, and the damping gradually increases, and the overcurrent channel is blocked to disconnect the high and low pressure areas; the second excitation coil The module (29) is energized, the current increases from small to large, the low-pressure oil port (26) is gradually closed, and the internal back pressure of the retarder gradually increases, which in turn causes the braking force to gradually increase to achieve the retarding effect.