JPS61109939A - Differential controller for vehicle - Google Patents

Abstract

PURPOSE:To improve running performance of a vehicle, by actuating a differential controller to act when a difference between rotary speeds of a driving shaft to be connected with a differential mechanism and a turning angle of the vehicle are under certain established states. CONSTITUTION:A differential controller whose action is started or released by a hydraulic pressure generating device 47 is provided in a differential mechanism 1 connected with a propeller shaft P. The hydraulic pressure generating device 47 is operated by instructions of an electronic controller. The electronic controller 4 gives intructions to the hydraulic pressure generating device 47 so that action of the differential controller is released when a difference between rotary speeds of one side and the other side driving shafts 21, 21 connected with the differential mechanism 1 and a turning angle of a vehicle has turned into a predetermined state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to control of a differential limiting device of a differential mechanism.

[Conventional technology 1] When the vehicle is on a road surface with a low coefficient of friction such as muddy, sandy, snowy, or icy roads, only one of the vehicle drive wheels may slip (slip), or one of the vehicle drive wheels may float when turning. If the torque transmission capacity to the road surface is insufficient, only one of the vehicle drive wheels tends to spin, resulting in a decrease in vehicle driving performance. To compensate for these shortcomings, when the difference in the output of the torque transmitted to one wheel drive shaft and the other wheel drive shaft in the differential mechanism exceeds a certain value, the torque is transmitted to the one wheel drive shaft and the other wheel drive shaft by mechanical operation of an internal mechanism. limit the torque that
A differential mechanism (limited-slip differential) is used that is equipped with a differential limiting device that prevents slipping on roads with a low coefficient of friction and improves driving performance when the vehicle turns.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, the differential limiting device of the differential mechanism is configured such that when the difference in output torque transmitted to one drive shaft and the other drive shaft exceeds a set value, Therefore, there has been a demand for a differential control device for a vehicle that can optimally control the differential limiting device depending on the driving conditions of the vehicle.

An object of the present invention is to operate the differential limiting device when the rotational speed difference between one and the other drive shafts connected to the differential mechanism and the vehicle turning angle of the vehicle equipped with the differential mechanism are set. By providing an instruction to activate the differential limiting device, the differential limiting device is activated only when the vehicle is running and under certain conditions.
An object of the present invention is to provide a differential control device for a vehicle that can optimally control a differential limiting device according to heavy vehicle running conditions and improve vehicle running performance.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the vehicle differential control device of the present invention includes a differential mechanism including a differential limiting device that receives the output of a vehicle transmission as an input, and the differential mechanism. A differential control device for a vehicle includes a differential control device for controlling operation of a differential limiting device, wherein the differential controlling device includes an actuating means for instructing the start of operation of the differential limiting device; and a release means for instructing activation/cancellation of the differential mechanism, and the activation means is configured to control a rotational speed difference between one drive shaft and the other drive shaft connected to the differential mechanism, and a vehicle turning angle of a vehicle equipped with the differential mechanism. The differential limiting device may be configured to provide an instruction to operate the differential limiting device when the differential limiting device is in a certain setting state.

[Operation and Effects of the Invention] In the vehicle differential control device of the present invention having the above-mentioned configuration, the differential control I device controls the rotational speed difference between one and the other drive shafts connected to the differential mechanism, and the differential control device according to the present invention. By providing the differential limiting device to operate when the vehicle turning angle of the vehicle equipped with the machine hM is in a certain setting state, the differential limiting device is activated only when the vehicle is running under predetermined conditions. This makes it possible to optimally control the differential limiting device according to vehicle driving conditions, improving vehicle driving performance and improving limited slip
The durability of the differential limiting device can be improved without spoiling the basic operation of the differential.

[Embodiment 1] Next, a differential control device for a vehicle according to the present invention will be explained based on an embodiment shown in the drawings.

FIG. 1 shows a block diagram of a vehicle differential control device according to the present invention.

E is an engine that generates power, King is a power transmission device such as a 1-Herc converter, A is a transmission that changes the speed and outputs the power of the engine E transmitted through the power transmission device T, and P is the speed changer. 1 is a differential mechanism connected to the propeller shaft P; 21 and 22 are differential mechanisms (for transmitting the output of 1 to the drive wheels 23 on one side and the drive wheels 24 on the other side); One wheel drive shaft and the other wheel drive shaft that transmit power, 31 and 32 indicate one idler wheel and the other idler wheel, 3 indicates one idler wheel 31 and the other idler wheel 32
a knuckle arm 33.34 connected to the support portion of the knuckle arm 33.34; and a tie rod 35 connected to the knuckle arm 33.34.
．． 36, a steering wheel 37 which is a steering device provided at an easily operated position in the vehicle interior and which determines the direction of travel of the vehicle, a steering shaft 38 which transmits the rotation of the steering wheel 37 to the front part, and the steering shaft. 4 is a steering device consisting of a steering gear 39 that transmits the rotation angle of 38 to the tie rods 35 and 36; 4 is the number of rotations (rotational speed) NR of each of the one wheel drive @ 21 and the other wheel drive shaft 22; A rotation speed sensor 41.42 that detects the rotation speed NL, a torque sensor 43.44 that detects the respective shaft torques TR and TL of the one wheel drive shaft 21 and the other wheel drive shaft 22, and Output shaft T
A vehicle speed sensor 45 that detects the rotation speed of 1 and detects the vehicle speed V.
and a steering angle sensor 4 attached to the steering shaft 1 to detect the turning speed (angle) of the steering wheel 37 and the turning angle of the vehicle.
I10 board 1-1 central processing unit CPU, which is an input board for inputting 6 and 6, and an output board for giving an output instruction to a hydraulic pressure generator 4γ which outputs intake negative pressure to the differential mechanism 1 and hydraulic pressure by an oil pump, etc.; Read-only memory ROM, random access memory RAM
It is an electronic control device consisting of.

FIG. 2 is an embodiment of the power transmission device HT and the transmission A, and shows a skeleton diagram of an automatic transmission for a vehicle that combines a torque converter and a planetary gear mechanism with four forward speeds and one reverse speed.

This automatic transmission has a power transmission device T with a torque converter applied, an overdrive mechanism OD, 3 forward speeds and 1 reverse speed.
The stage underdrive (includes several UDs) and is controlled by a hydraulic control device (not shown).

The power transmission device T is a well-known device having a pump 50, a turbine 51, a stator 52, and a direct coupling clutch 53, and the pump 50 is connected to an engine crankshaft 54.
The turbine 51 is connected to a turbine shaft 55. The turbine shaft 55 forms the output shaft of the power transmission device "" and also serves as the input shaft of the overdrive mechanism OD, and is connected to a carrier 56 of a planetary gear device in the overdrive mechanism OD.The carrier 56 allows the turbine shaft to rotate. A supported planetary pinion 57 meshes with a sun gear 58 and a ring gear 59. A multi-disc clutch CO, which is a frictional engagement device, is connected between the sun gear 58 and the carrier 56.
A one-way latch FO is provided in parallel, and a multi-disc brake Bo, which is a friction detection engagement device, is provided between the sun gear 58 and the overdrive case 60 that includes the overdrive mechanism OD. ing.

The ring gear 59 of the overdrive IfilNOD has 3 forward stages and 1 reverse stage, and the underdrive is the input shaft 6 of the UO.
1. A multi-disc clutch C1, which is a forward clutch, is provided between the input shaft 61 and the intermediate shaft 62, and a multi-disc clutch C2, which is a reverse clutch, is provided between the input @1161 and the gear shaft 63. A multi-disc brake B1, a multi-disc brake B2, and a one-way latch F1 are provided between the sun gear shaft 63 and the transmission case TC. , the carrier 65
A planetary pinion 66, a ring gear 67 meshing with the pinion 66, another carrier 68, a planetary pinion 69 supported by the carrier 68, and a ring gear 70 meshing with the pinion 69 in two rows. It constitutes a single planetary gear set. The ring gear 67 is connected to the intermediate shaft 62, the second row of carriers 65 is connected to the first row of ring gears 70, and these carriers 65 and ring gears 10 are connected to the output shaft 7.
1 is connected. A multi-plate brake B3 and a one-way clutch F2 are provided in parallel between the first row of carriers 68 and the transmission case TC.

This 1 mA gear shift involves engaging or releasing each clutch and brake depending on the vehicle running conditions such as the throttle opening of the engine E and the vehicle speed.
Automatic or manual shifting of four forward speeds including D) and one reverse speed of only manual shifting are performed.

Table 1 shows the transmission gear positions and the operating states of the clutches and brakes.

Table 1 shows the relationship between the shift position SP of the shift lever during automatic shifting, the engagement state of each FJt (brake and clutch), and the planetary gear transmission mechanism. Energized (ON), ×
indicates non-energization (OFF), O indicates engagement of the frictional engagement element, and blank indicates disengagement.

Table 1 Figure 3 shows the differential machine (Toma 1 and hydraulic pressure generator 4).
An example of No. 7 is shown below.

The differential mechanism 1 includes the propeller shaft P
A ring gear 110 receives power transmitted through a drive pinion (not shown), and the ring gear 1
10, a differential pinion shaft 120 is driven by a differential case 111 connected to the differential pinion shaft 120, and a differential pinion 13 is rotatably attached to the outer periphery of the differential pinion shaft 120.
0, one side differential lead gear 142 that meshes with the differential pinion 130 and has a spline 141 spline-fitting one wheel drive shaft 21 on the inner periphery, and drives the one wheel drive shaft 21; the differential pinion; A spline 143 that meshes with 130 and spline-fits the other wheel drive shaft 22 on the inner periphery.
and the other side differential side gear 144 that drives the other wheel drive shaft 22, and the differential limiting device 1.
Consisting of 50. The differential case 111 is a housing 11 that includes the Y-IF7 differential pinion 130, differential side gears 142, 144, etc.
2 and a lid portion 113, which are fastened together with a plurality of bolts 114 with a ring gear 110 interposed therebetween. The differential limiting device 150 is spline-fitted between a case side spline 151 provided on the inner periphery of the housing 112 and a side gear side spline 152 corresponding to the case side spline 151 and provided on the outer periphery of the one side differential side gear 142. A multi-disc clutch 153 provided together with the multi-disc clutch 15 of the lid portion 113
A screw 155 is fitted into the cylinder 154 opened on the third side and engages and disengages the multi-disc clutch 153, and a hydraulic servo 156 drives the piston 155 by supplying and discharging hydraulic oil from the hydraulic pressure generator 47. Become.

In this embodiment, the hydraulic pressure generating device 47 switches between the solenoid valve S, which sets the solenoid pressure at a high level, and the switching valve 470, by energizing the line pressure regulated by the hydraulic control device (not shown) of the transmission 11A. The switching valve 470 is provided with a spool 473 having an upper end land 471 and a lower end land 472.
, the one F end oil chamber 474 which receives solenoid pressure from the solenoid valve S, and the anti-λ of the upper end oil chamber 474 of the subroutine 473.
The solenoid valve S is disposed in the upper end oil chamber 475 on the first side, and when the solenoid valve S is energized and a low level solenoid pressure is applied to the upper end oil chamber 474, the spool 473 is urged toward the upper end oil chamber 474, When the solenoid valve S is energized and high-level solenoid pressure is applied to the upper end oil chamber 474, the spring 476 is set to contract due to the urging force of the solenoid pressure. When the oil 1474 receives high-level solenoid pressure and is located in the lower part of the drawing, a line pressure oil passage 477 that receives line pressure supply and a servo oil passage 478 that communicates with the hydraulic servo 156 of the differential limiting device 150 are connected. The upper end land 471 and the lower end land 412 communicate through an intermediate oil chamber 479, and when the solenoid valve S is de-energized, the spool 473 is connected to the spring 47.
6, the line pressure oil passage 411 and the servo oil passage 478 are connected to the lower end land 41 of the spool 473.
2 so as to prevent communication.

The operation of the vehicle differential control device of the present invention will be explained based on a flowchart programmed in the electronic control device 4 in FIG.

First, turn the starter key ON, turn 9 engines (401), and set one wheel drive shaft to 210 rotations NR.

Rotational speed N[ of the other wheel drive shaft 22, cutting angle e of the steering wheel 37, vehicle speed V, shaft torque TR1 of one wheel drive shaft 21 shaft torque ' of the other wheel drive shaft 22
, 'TLI7) respectively as NH-4, N1. =O1e=0,
v = 0, TR = 0, TL = O and the first 1ll) lio settings (402), and the rotation speed NR of one wheel drive @ 21 and the rotation speed NR of the other wheel drive @ 21 are determined from the rotation speed sensor 41.42.
22 rotation speed N is read (403), and the steering wheel 37 is read from the steering angle sensor 46.
404), reads the output shaft rotation speed of the speed change BiA from the vehicle speed sensor 45,
Convert the vehicle speed ■ from the output shaft rotation speed 405), then calculate the relative relationship between the cutting angle e and the vehicle speed ■ f(C), v)
406) Divide the rotation speed NL of the other wheel drive shaft 220 by the rotation speed NR of one wheel drive shaft 21, and set this value as NX. 407)
, NX is greater than 1 (h) or not (408
), No (NX is smaller than 1), convert the value of NX to 1/N×, and proceed to the next step (410) (409).

If YES (NX is greater than 1), proceed to (410). In (410), it is determined whether the value of NX is within the range of ±α (α = setting range) of NY set in (406), and if YES (NX is within the range of Ny±α). If so, the process returns to (403), and if No (Nx is outside the range of Ny±α), an instruction is given to energize the solenoid valve S that operates the differential limiting device 150 (411). Next, the shaft torque TR of one wheel drive shaft 21 is determined by the torque sensors 43 and 44. The torque T of the other wheel drive shaft 22 is read (412), and then the other wheel drive shaft 2
2 shaft torque T and one wheel drive shaft 21 shaft torque T
Divide by R and set the value as Tx 413), then judge whether the value of Ding X is within the range of 1 ± β (β = setting range) (414), NO (King 1±β range), return to (412) and answer YES (Tx is 1±β
(within the range of
, then return.

FIG. 5 shows a differential control device for a vehicle including another embodiment in which the present invention is applied to a center differential of a four-wheel drive device. As in the previous embodiment, E indicates an engine that generates power, and O indicates an engine such as a torque converter. The power transmission device A is a transmission that changes the speed and outputs the power of the engine E transmitted via the power transmission air, and at the rear of the speed change IA there are 1 to 1 to 1-ranshufu which switch and transmit the power to the four wheels or the rear wheels. /7 F
has been concluded. FP is the front propeller shaft, which is one drive shaft that transmits the output of Transfer F to the front, and RP is the other drive shaft, which transmits the output of Transfer F to the rear. Differential mechanism 1
A center differential 100 is provided. 1A is a differential connected to the front propeller shaft FP, and the power transmitted to the front propeller shaft FP is transmitted to the front right wheel 23A and the front left wheel 24A via the right wheel drive shaft 21A and the front left wheel drive shaft 22A. 1B is a differential agricultural structure connected to the rear propeller shaft RP, and the power transmitted to the rear propeller shaft RP is transmitted to the rear right wheel 27A and the rear left wheel via the rear right wheel drive shaft 25A and the rear left wheel drive @26A. 28A
transmits power to. 3A is a knuckle arm 33A connected to the support portions of the front right wheel 23A and the front left wheel 24A.
, 34A, the tie rods 35A, 36A connected to the knuckle arms 33A, 34A, the steering wheel 37A, which is a steering device provided at an easily operable position in the vehicle interior and determines the direction of travel of the vehicle, and the steering wheel. This steering device includes a steering shaft 38A that transmits the rotation of the steering shaft 37A to the front part, and a steering gear 39A that transmits the rotation angle of the steering shaft 38A to the tie rods 35 and 36A. I have rotational speed sensors 41A and 42A that detect the rotational speeds (rotational speeds) Nr and Nr of the front propeller shaft FP and rear propeller shaft RP, respectively, and shaft torques of the front propeller shaft FP and rear propeller shaft RP, respectively. Torque sensor 4 that detects lf, l-r
3A, 44A, and an application sensor +J45A that detects the number of 710 times vi of the output shaft within the above-mentioned speed change age Δ and detects single series ■
and the notch m (angle) of the steering wheel 37A.
It is an input boat that inputs the steering angle sensor 46A attached to the steering shaft 388 to detect the turning angle of the vehicle. I10 boat, which is an output port that gives an output instruction to the hydraulic pressure generating device 47A, and the central processing unit CP
This is an electronic control device consisting of U, read-only memory ROM, and random access memory RAM.

FIG. 6 shows a sectional view of the transformer 77F and the center differential 10O.

The output @71 of the speed change mA is connected via a sleeve 72 to the input shaft 13 of the differential 1A, which is the differential mechanism 1, by a spline.

The center differential 100 includes a differential pinion shaft 120A connected to the input shaft 73, a differential pinion 130A supported by the differential pinion shaft 120A, and differential side gears 142A and 144A that mesh with the differential pinion 130. 8 is connected to a rear wheel drive output shaft 74 that drives a rear propeller shaft RP. The differential side gear 1428 is connected to one end of an intermediate shaft 75 rotatably disposed on the input shaft 73.
A spur gear 77 of a selective meshing means 7G is connected to the shaft end of the shaft. Further, a clutch cylinder 78A is spline-fitted to the intermediate shaft 75, and a differential limiting device 1508 is provided between the clutch cylinder 78A and a housing 112A fixed to the differential pinion shaft 120A to removably connect the two. It is provided so that engagement and disengagement are performed in response to the picture movement of the hydraulic pressure generating device 47. 1
The selection meshing means 76' includes a spur gear 77 connected to the intermediate shaft 75 and a spur gear 7 rotatably disposed on the sleeve 772.
8. A transmission gear 79 formed integrally with the spur gear 78, and a shaft 8 connected to a shift lever (not shown) in the driver's seat.
Depending on the position of the shift lever, during two-wheel drive, a gear 82 is provided on the shift fork 81 as shown by the solid line in the figure.
Since the gear 78 only meshes with the spur gear 77, the torque of the intermediate shaft 75 is not transmitted to the transmission gear 79.During four-wheel drive, as shown by the dotted line in the figure, the gear 82 is Since it meshes with the spur gear 77 and the spur gear 78, the torque of the intermediate shaft 75 is transmitted to the spur gear 79.

The transmission gear 79 is a gear 8 provided on a front wheel drive output shaft 83 disposed parallel to the output 11i11171 of the transmission type A.
4 through a chain 85. Front wheel drive output shaft 83 drives front propeller shaft FP.

In FIG. 7, the operation of the vehicle differential control system of the present invention applied to the center differential of a four-wheel drive vehicle will be explained based on flowcharts 1 to 1 programmed in the electronic control device 48.

First, turn on the starter key to start the engine 4
01A), rotation speed N of the front propeller shaft FP
f, the rotation speed N of the rear propeller shaft RP, the cutting angle e of the steering wheel 37A, the vehicle speed ■, the axial torque T of the front propeller shaft FP, and the axial torque lr of the rear propeller shaft RP, respectively, Nf=0, Nr=
o, e 0. v-〇, Tf = 0. Set Tr = O and initial mi (402A), and rotate speed sensor 4
1A and 42A read the rotation speed N of the front propeller shaft FP and the rotation speed Nr of the rear propeller shaft RP (403A), and read the turning angle e to the steering wheel 37 from the steering angle sensor 46A (404A). , read the output shaft 110 rotation speed of the transmission 11A from the vehicle speed sensor 45A, and calculate the vehicle speed ■ from the output shaft rotation speed (405A), then calculate the relative relationship between the cutting angle O and the vehicle speed ■ as f (e,
406A), the rotation speed Nr of the rear propeller shaft RP is divided by the rotation speed N of the front propeller shaft FP, and the value is set as Nb.407A), Nb is 1. It is determined whether the value is larger than 1 (408A), and if No (Nb is smaller than 1), the value of Nb is converted to 1/Nb, and then (7) (41
0A) (409A). If YES (Nb is greater than 1), proceed to (410A). In (410A), the first shift of Nb is set at (406A) at the intersection α(
α = setting range).
If YES (Nb is within the range of Na±α), (403A
), and if No (Nb is outside the range of Na±α), the hydraulic pressure generator 47 operates the differential limiting device 150A.
Give instructions to A (411A). Next, the torque sensor 43
A, Front propeller shaft FP 1 from 44A
lIIll l Berg T [and rear propeller shaft R
Read axis i to silk r of P (412A)
, divide the axial torque Tr of the rear propeller shaft RP by the axial torque T of the front propeller shaft FP, and let the value be TC413A), then the value of TC is 1±β (β=
(41) is within the range (setting range).
4A), if No (Tc is outside the range of 1±β), (
Returning to step 412A), if YES (TC is within the range of 1±β), an instruction to de-energize the solenoid S is given to release the operation of the differential limiting device 150 (step 4158), and then the process returns.

In the above embodiment, the differential J3 and release of the differential limiting device are performed by a hydraulic pressure generating device that supplies and discharges hydraulic pressure, but the differential limiting device may be engaged and disengaged by electromagnetic force.

In the above embodiment, the differential limiting device is operated based on the relationship between the turning angle of the vehicle, the vehicle speed, and the difference in rotational speed between one and the other drive shaft, but the vehicle speed may not be used.

In the above embodiment, the differential limiting device is operated by increasing the rotation ratio of one drive shaft and the other drive shaft, but the rotation ratio of one drive shaft and the other drive shaft is small, and If the turning angle is small, for example, using vehicle speed,
The differential limiting device may be set to move n when the vehicle speed exceeds a set value, and may be provided to improve straight-line stability during high-speed driving.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the vehicle differential control device of the present invention, Fig. 2 is a schematic skeletal diagram of gear shifting, Fig. 3 is a sectional view of the differential mechanism and hydraulic pressure generator, and Fig. 4 is a differential control system. Flowcharts 1 to 5 of the control device are block diagrams showing another embodiment in which the Dino Allencial System 13II device of the present invention is applied to a four-wheel drive vehicle, and FIG. The cross-sectional view, FIG. 7, is a flowchart of a differential control device applied to a center differential. In the figure 150...Differential limiting device 1...Differential rock structure 4.4A...Electronic control device 47.4
7A...Hydraulic pressure generator 41.41A, 42.4
2A...Rotation speed sensor, $3.43A, 44.
448... Torque sensor 45.45A... Φ speed sensor 46.46A... Steering angle sensor 2
1... One wheel drive shaft 22... Other wheel drive shaft 37... Steering wheel △... Gear shift FP... Front 1 propeller shaft RP... Rear propeller shaft

Claims (1)

[Scope of Claims] 1) A vehicle differential comprising a differential mechanism including a differential limiting device that receives the output of a vehicle transmission as input, and a differential control device controlling the operation of the differential limiting device of the differential mechanism. In the control device, the differential control device includes an actuation device that instructs to start the operation of the differential limiting device, and a canceling device that instructs to cancel the operation of the differential limiting device, and the actuating device includes the actuating device that instructs to start the operation of the differential limiting device. When the rotational speed difference between one and the other drive shafts connected to the differential mechanism and the vehicle turning angle of the vehicle equipped with the differential mechanism are in a certain setting state, an instruction to operate the differential limiting device is given. A differential control device for a vehicle, characterized in that: 2) The release means is provided to give an instruction to release the differential limiting device when there is a difference in drive shaft torque between the one and the other drive shafts. A vehicle differential control device according to claim 1. 3) The actuating means is configured to issue an instruction to actuate the differential limiting device when the ratio of the rotational speeds of the one and the other drive shafts is outside the range of the relative relationship between the vehicle turning angle and the vehicle speed. A vehicle differential control device according to claim 1, characterized in that: