JPS63192621A - Differential controller - Google Patents

Abstract

PURPOSE:To enable traction and revolution to be compatible by forming graphs mode by mode so that the pressure varies in accordance with change in the running condition of the car. CONSTITUTION:This differential control device 10 is a one to control differential motion of a differential device 14 having a differential motion restricting mechanism 12, which enables restriction of differential motion continuously, and includes a means 16 to sense the car running condition, a mode selecting means 18, a controller 20, and a maneuvering means 22. The mode selecting means 18 permits selection of different modes to give commands to the controller 20 externally and to select any specific graph on the map stored in the controller, and it can be formed from changeover switches.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a differential control device, and more particularly, the present invention relates to a differential control device installed in a vehicle that is equipped with a differential IJ limit mechanism that can continuously limit the differential. This invention relates to a device that increases the differential of a dynamic device by 1.11 m.

(Prior art) A device for controlling the differential of a differential gear equipped with a mechanism capable of limiting differential differential, in which the differential: tI11 limit is switched by a manual switch according to the acceleration state of the vehicle. A control device has been proposed (Japanese Patent Laid-Open No. 61-10
Publication No. 2321).

(Problems to be Solved by the Invention) In the differential i control device described in the above-mentioned publication, either the differential limiting amount as a whole is switched to multiple stages, or the differential limiting amount for each stage is changed depending on the acceleration of the vehicle. It remains constant regardless of the state. Therefore, when the selected differential limiting amount is large, even if traction is improved, turning performance is deteriorated. Conversely, if the differential limiting amount is selected to be smaller, the turning performance will improve, but the traction will decrease.

The aforementioned defects occur when you need to gain traction.
This problem can be solved by frequent switching operations, such as switching the differential limiting amount to a smaller amount when it is necessary to increase turning performance by switching the differential limiting amount to a smaller amount. However, since the switching operation is performed while the heavy vehicle is in operation, it is not only troublesome for the driver but also prevents the driver from concentrating on driving, which is undesirable.

An object of the present invention is to provide a differential control device that can achieve both traction and turning performance.

(Means for Solving the Problems) The present invention is a device for controlling the differential of a differential device that operates a differential limiting mechanism that can continuously limit the differential, and a mode selection means capable of selecting a plurality of modes, and a graph formed so that the pressure to be applied to the surface differential limiting mechanism changes as the running condition of the vehicle changes; controlled by a controller storing a map having the same number of graphs showing the correlation between running conditions and pressure as the number of modes selected by the mode selection means, and a signal from the controller;
and means for operating the differential limiting mechanism.

Vehicle running conditions include steering angle, drive torque, vehicle speed, etc.
Or more than one is detected.

(Function and Effect) When the driver selects an arbitrary mode using the mode selection means, the controller uses the graph corresponding to that mode on the map to determine what should be applied to the differential; -1 limit mechanism based on the vehicle running state. Get pressure. This pressure is applied to the differential limiting mechanism by the operating means, and a differential is created in accordance with the pressure.

Since the graph for each mode is formed so that the pressure changes as the running condition of the vehicle changes, it is possible to achieve both traction and turning performance.

(Example) As shown in FIGS. 1 and 4, the differential control device 10 is a device that controls the differential of a differential device 14 having a differential limiting mechanism 12 that can continuously limit the differential. means 16 for detecting the running state of the vehicle; mode selection means 18;
It includes a controller 20 and operating means 22.

The differential device 14 includes a differential case 24, a plurality of pinions 26 and a pair of side gears 28 (one is shown in the figure), and a shaft connected to each side gear 28. 30.

The differential; 1111 limiting mechanism 12 continuously limits the differential movement of the differential device 14, and includes a plurality of first friction plates 32 that engage with one side gear 28 and a plurality of first friction plates 32 that engage with the differential case 24. and a plurality of second friction plates 34 that fit together. A first differential carrier 36 is fixedly disposed surrounding the differential case 24 and rotatably supports the differential case 24.

'f, 2 differential carrier 38 is attached to the first differential carrier 36.

A cylindrical spacer 40 is non-rotatably attached to the shaft 30, and a first friction plate 32 is supported by the spacer 40 so as to be non-rotatable and movable in the axial direction of the shaft 30. On the other hand, a transmission member 42 non-rotationally coupled to the differential case 24 is disposed surrounding the shaft 30.

The transmission member 42 is connected to the first differential carrier 3
The diameter is expanded at a portion beyond 6, and a second friction plate 34 is supported in this expanded diameter portion so as to be non-rotatable and movable in the axial direction. The first friction plate 32 and the second friction plate 34 are
arranged alternately. A second differential carrier 38 surrounds the transmission member 42 .

The piston chamber 4 is located in the second differential carrier 38.
4 is provided, and a first piston 46 is movably and non-rotatably disposed within the piston chamber 44 . A second piston 48 is spaced apart from the first piston 46 and is non-rotatably and axially movably supported by the spacer 40. A thrust bearing 50 connects the first piston 46 and the second piston 4
8. When hydraulic pressure is introduced into the piston chamber 44, the first piston 46 is pressed against the second piston 48 via the thrust bearing 50, and between the first friction plate 32 and the second friction plate 34, A friction force proportional to the pressing force is generated. This frictional force limits the differential movement of the differential device 14. The pressing force applied to the friction plates 32 and 34 is
Thrust washer 52.54 and thrust bearing 5
6 to the differential carrier 36, where the reception is stopped.

The first stage 16 for detecting the running state of the vehicle can be composed of one or more of a potentiometer for detecting a steering angle, a wheel torque meter for detecting drive torque, a tachometer for detecting vehicle speed, and the like. In the illustrated case, the steering angle is detected.

The mode selection means 18 is capable of selecting a plurality of modes, and is configured to give a command from the outside to the controller 20 to select a specific graph of the map stored in the controller, and can be constituted by a changeover switch.

The controller 20 is a CPU or a computer. The controller 20 uses the above-mentioned graph that is formed so that the pressure to be applied to the differential-J limit mechanism 12 changes as the eastbound driving condition changes, and that shows the correlation between the driving condition and pressure for each mode. It stores maps having the same number of modes as the number of modes selected by the mode selection means.

In the embodiment shown in FIG. 2, the map 58 shows the steering angle δ and ζt.
The correlation with the dJ hydraulic pressure P has three graphs a, b, and c shown for each mode corresponding to the three modes a, b, and c, and this map 58 is stored in the controller 20. Baru. The control hydraulic pressure is used to determine the differential limiting amount of the differential limiting mechanism 12, and when the hydraulic pressure is high, the differential limiting amount is large;
When the lock state is approached and the hydraulic pressure is low, the differential restriction amount is small and the restriction is removed, that is, the free state approaches. In addition,
Maps can also be formed so that one map corresponds to one graph.

In the map 58 of FIG. 2, all graphs show that the control hydraulic pressure remains almost constant until the steering angle reaches a constant value δ1, and as the steering angle becomes larger than δ, the control hydraulic pressure tends to decrease. With either graph, it is possible to achieve both Traxidin and turning performance. here,
- The constant value δ1 is the limit angle at which it can be considered that the vehicle is traveling substantially straight.

In the embodiment shown in FIG.
Three graphs e, f, g are shown for each mode in which the correlation between
This map 60 is stored in the controller 20. In either case, when the drive torque is large, the hydraulic pressure tends to increase to ensure the traction, and when the drive torque is small, the hydraulic pressure tends to decrease to prevent a decline in turning performance. However, the way the curve rises has characteristics such as a linear graph f, a gradual curve e after reaching a predetermined driving torque, and a steep curve g.

The operating means 22 includes a liquid pump 70, an unload relief valve 72, an accumulator 74, and a current-controlled pressure reducing valve 7.
6 and a check valve 78.

A tube 80 is connected to the pump 70 and the second differential carrier 38 of the differential limiting mechanism 12, and the tube 80 communicates with the piston chamber 44. An unload relief valve 72 is installed in the pipe 80 , and a current-controlled pressure reducing valve 76 is installed in a portion leading from the unload relief valve 72 to the differential limiting mechanism 12 .

Further, the accumulator 74 is connected to the unload relief valve 7.
2 and the current-controlled pressure reducing valve 76, and the check valve 7
8 is an unload release valve 72 and an accumulator 74
be incorporated between. The check valve 8 only allows liquid flow or pressure transmission from the unload relief valve 72 to the accumulator 74 .

When pressurized liquid is supplied from the pump 70, the unload seat of the unload relief valve 72 is closed, and the check valve 78 is closed.
opens. As a result, pressurized fluid from pump 70 is directed through tube 80 to accumulator 74, where the fluid pressure increases. The pressure in the accumulator 74 is increased by the unload relief valve 7.
2, the unload relief valve 72 opens instantly and the pressure liquid from the pump 70 is transferred to the reservoir tank 8.
2, and the reverse valve 78 closes. Thus, a constant pressure is stored in the accumulator 74.

The current-controlled pressure reducing valve 76 has a DC solenoid in its pilot section, and controls the pressure continuously and steplessly by controlling the input current to the solenoid. The control pressure in this case is then substantially proportional to the input terminal. Therefore, if the controller 20 applies the current that should produce the controlled hydraulic pressure stored in the controller 20 to the current-controlled pressure reducing valve 76, the current-controlled pressure reducing valve 76 will obtain an appropriate hydraulic pressure, and this hydraulic pressure will make a difference. The differential motion of the motion limiting mechanism 12 is limited.

(Operation of Actual hM Example) When the vehicle equipped with the differential control device 10 runs, the running state detection means 16 operates and a signal is sent to the controller 20. For example, when the driver selects mode b, the controller 20 controls the control hydraulic pressure P according to the magnitude of the steering angle δ.
is obtained from graph b in FIG. Then, the 114 J control current that should produce the control hydraulic pressure P is obtained from a map or the like as appropriate, and this control current is output to the current control pressure reducing valve 76 of the operating means 22. As a result, the hydraulic pressure P is supplied from the current-controlled pressure reducing valve 76 to the piston chamber 44 of the differential limiting mechanism 12, and the friction plate 32.
34 come into contact with each other with a frictional force corresponding to the hydraulic pressure P, and the differential movement of the differential device 14 is limited.

While driving, when the magnitude of the steering angle δ changes, the magnitude of 1tI (1g4 hydraulic pressure P changes), but since the graph is formed so that both traction and turning performance can be achieved, the steering angle δ is wide. Traction and turning performance are ensured throughout the range.

If the driver wants to secure a larger traction, the driver selects mode a and uses graph a.
A command may be given to the controller 20. On the other hand, if the driver wants to improve turning performance, the driver selects mode C and causes the controller 20 to use graph C.

When the means 16 for detecting the running state is configured to detect the drive torque, the map 60 of FIG. 3 is stored in the controller 20.

If the driver selects mode f and graph f is being used, when emphasis is placed on traction reinforcement, the driver selects mode e and issues a command to controller 20 to use graph e.

In addition, only when the driving torque is high such as during acceleration, when the driver selects mode g and uses graph g, when the driving torque is 7 minutes if the torque is maintained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the differential control device, FIGS. 21-a and 3 are schematic diagrams of maps, and FIG. 4 is a sectional view of the differential control device. 10: Differential control device, 12: Differential limiting mechanism, 14: Differential device, 16: Stage for detecting running state, 18: Mode selection means, 20: Controller, 22: Operating means, 32.34:) '#PJ board, 44: Piston chamber, 58.60: Map, 76: Current control pressure reducing valve. Agent Patent Attorney Nobuyuki Matsunaga Fig. 1 Fig. 2 δ, , Rudder angle (δ) Fig. 3 Driving torque (T)

Claims (1)

[Claims] A device for controlling the differential of a differential gear having a differential limiting mechanism capable of continuously limiting the differential, comprising means for detecting a running state of a vehicle, and mode selection means capable of selecting a plurality of modes. , the mode selection means selects a graph that is formed such that the pressure to be applied to the differential limiting mechanism changes as the driving condition of the vehicle changes, and that shows the correlation between the driving condition and pressure for each mode. A differential control device comprising: a controller storing maps having the same number of modes as the number of modes; and means controlled by a signal from the controller to operate the differential limiting mechanism.