JPS62110530A - Differential limiting controller for vehicle - Google Patents

Abstract

PURPOSE:To make braking control over an antiskid device so favorably as well as to improve the extent of safety, by controlling the antiskid device so as to release a differential limit by a differential limiting device at the time of its operation. CONSTITUTION:A vehicle is provided with a differential device at the point midway in a power transmission route, which distributes and transmits engine power to symmetrical driving wheels 1 and 2 while allowing their differential motion. This differential device 3 is equipped with a differential limiting device 4 of a multiple disc friction clutch or the like generating differential limiting torque between its input and output parts by control external force, and the said device 4 is controlled by a controlling device 6 according to output of each input sensor 5 detecting a vehicle state such as car speed, accelerator opening or the like. In this case, a sensor 501 detecting operation or nonoperation of an antiskid device is installed in one of the input sensors 5, and when the said sensor 501 detects the operation of the antiskid device, a differential limit by the differential limiting device 4 is made so as to be released by the controlling device 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides a differential for a vehicle that generates a differential limiting torque by a control external force on a differential limiting means and controls the differential limiting according to predetermined control conditions. This invention relates to a restriction control device.

(Prior Art) As a differential device equipped with a conventional differential limiting means, for example, the one described in "Complete Book of Automotive Engineering, Volume 9, Power Transmission Device" (published by Hayashizankaido on November 15, 1980), pages 321 to 321 3
Devices such as those described on page 24 are known.

In this conventional device, a multi-plate friction clutch provided between the differential case and the side gear is used as a differential limiting means. This device was equipped with so-called torque proportional differential limiting means, which uses the thrust force generated by the clutch as a clutch engagement force, and uses this clutch engagement force to generate a differential limiting torque.

Note that the differential limiting means here refers to a means for exerting a differential limiting function, and a device usually referred to as a limited slip differential is a differential device with a built-in differential limiting -1 stage that can control both differentials. Differentiate simply by differential device (differential means)
If it is written as , it is a normal differential device without a limiting function (
(conventional differential).

In addition, as an anti-skid device installed in the braking system, for example, "New Automotive Engineering Handbook J (1)
The one described on pages 6-36 of ``Published by Tosho Shuppansha, May 25, 1981'' is known.

This anti-skid brake device (Anti Broc
The kSystem (also known as ABS) controls the braking oil pressure while detecting the wheel rotation speed, and reduces the wheel slip rate to approximately 10% so that the maximum friction coefficient is always obtained regardless of road surface, tire, etc. conditions. This is a device that attempts to prevent the wheels from locking up during braking by maintaining the vehicle speed within the range of 11-20%.

(Problem to be Solved by the Invention) However, in such a conventional device, the differential limiting action of the differential gear equipped with the differential limiting means and the operation of the anti-skid device are not mutually linked. Because they were unrelated, the differential was limited even when the anti-skid device was activated, making the anti-skid device's braking control impossible or reducing the braking performance of the anti-skid device. There was a problem.

For example, in an anti-skid device that independently controls the braking of each of the four wheels, due to limited differential, the braking torques of the left and right rear wheels interfere with each other, making braking control impossible and causing the rear wheels to lock. , the stopping distance becomes longer.

In addition, anti-skid devices that brake the left and right front wheels independently, detect the wheel rotation of the left and right rear wheels at the differential device position, and simultaneously control the left and right rear wheels by limiting the differential. Since the left and right rear wheels are directly connected to each other and a large inertia force is exerted by the entire rear wheel, the decompression time to obtain the target deceleration becomes longer and the convergence characteristics to the target deceleration are subject to large fluctuations. This results in a long stopping distance, an unstable ride, and poor ride comfort.Furthermore, when the brakes are applied slowly, the possibility of the rear wheels collapsing increases, reducing the braking performance of the anti-slip device.

(Means for Solving the Problems) The present invention was made for the purpose of solving the problems mentioned in L. To achieve this purpose, the present invention employs the following solving means. did.

The solution of the present invention will be described with reference to the conceptual diagram of the claims shown in FIG. 1. The differential means 3 distributes and transmits engine driving force to the left and right drive wheels 1.2 while allowing a differential, and the differential means Differential limiting means 4 is provided between the drive input section and the drive output section of No. 3, and generates a differential limiting torque by an external control force.
A differential limiting control device for a vehicle, comprising: an input sensor 5 that detects a vehicle state; and a control means 6 that outputs a control signal that increases or decreases differential limiting torque based on an input signal from the input sensor 5. , the input sensor 5 includes an anti-skid operation sensor 501 that detects activation/non-operation of an anti-skid device provided in the braking system, and controls the control means 6 to release the differential restriction when the anti-skid device is activated. It was used as a means to do this.

(Function) Therefore, in the vehicle differential restriction control device of the present invention, as described above, when the anti-skid device is activated, the differential restriction is released. Ordinary differential bag δ without differential limiting action
Therefore, it does not affect the braking control of the anti-skid device or the braking performance of the anti-skid device.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In describing this example, an automobile differential limiting control device equipped with a multi-disc friction clutch means operated by external hydraulic pressure will be used as an example. Take.

First, the configuration of the embodiment will be explained.

As shown in FIGS. 2 to 4, the embodiment device includes a differential device (differential means) 10, a multi-disc friction clutch means (differential limiting means) 11, a hydraulic pressure generator 12. control unit(
control means) 13, and an input sensor 14,
Each configuration will be described below.

The differential device 10 has a differential function of providing a speed difference between the left and right wheels according to the rotational speed difference in a driving state where a rotational speed difference occurs between the left and right wheels, and a differential function that equalizes the engine driving force to the left and right driving wheels. This is a device that has a driving force distribution function that distributes and transmits the driving force.

This differential device 10 is housed in a housing 16 that is attached to the vehicle body by a stud port 15, and includes a ring gear 17, a differential case 18,
It includes a pinion mate shaft 19, a differential pinion 20, and side gears 21 and 21'.

The differential case 18 includes a housing 16
It is rotatably supported by tapered roller bearings 22°22'.

The ring gear 17 is connected to a differential case 18.
The propeller shaft 23 is fixed to the propeller shaft 23 and meshes with a drive pinion 24 provided on the propeller shaft 23, from which rotational driving force is input.

The side gears 21, 21' include a left wheel drive shaft 25 and a right wheel drive shaft 2, which are drive output shafts.
6 is provided for each.

The multi-disc friction clutch means 11 is provided between the drive input section and the drive output section of the differential device 10, and is a means to which clutch engagement force is applied by external hydraulic pressure and generates a differential limiting torque.

This multi-disc friction clutch means 11 is housed in a housing 16 and a differential case 18, and includes a multi-disc friction clutch 27.27', a pressure ring 28.28', a reaction brake 29.29
', Thrust bearing 30.30' Spacer 31.31',
Bunsch rod 32, hydraulic piston 33. It is equipped with an oil chamber 34 and a hydraulic boat 35.

The multi-disc friction clutch 27, 27' includes friction plates (27a, 27'a) fixed in the rotational direction to the differential case (drive input part) 18, and fixed in the rotational direction to the side gear (drive output part) 21, 21'. pressure rings 28 and 28' on both axial end faces.
and a reaximin plate 29.29' are arranged.

The pressure ring 28, 28' is provided in a fitted state on the pinion mate shaft 19 as a member receiving the clutch engagement force, and the fitting portion is connected to the shaft having a rectangular cross section as shown in FIG. It is fitted into the end portion 19a by square grooves 28a, 28'a, and has a structure in which no thrust force is generated due to a rotational difference, unlike the conventional torque proportional differential limiting means.

The hydraulic piston 33 moves in the axial direction (to the right in the drawing) by supplying hydraulic pressure to the hydraulic boat 35, and engages both the multi-disc friction clutches 27, 27' according to the hydraulic pressure level. In the clutch 27, the engagement force is transmitted from the bushing rod 32 to the spacer 31 to the thrust bearing 30 to the reaction plate 29.
8 as a reaction force receiver, and the other multi-plate friction flange 27' is fastened using the fastening reaction force from the housing 16 as a fastening force.

As shown in FIG. 4, the hydraulic pressure generating device 12 is an external device that generates hydraulic pressure for clutch engagement force, and is a hydraulic pump 40.
, a pump motor 41, a pump pressure oil line 42, a drain oil line 43, a control pressure oil line 44, and a valve solenoid 45 as a valve actuator.
It is equipped with 6.

The pump motor 41 is a motor that is activated or deactivated by a motor signal (m) from the control unit 13, and is operated when driving and when differential restriction is being performed or there is a possibility that differential restriction is being performed. At certain times, a motor signal (m) due to energization is output, and when no differential restriction is required, such as when the vehicle is stopped, a motor signal (m) due to de-energization is output.

The electromagnetic proportional pressure reducing valve 46 controls hydraulic oil at bomb pressure supplied from the hydraulic pump 40 via the pump pressure oil line 42 under control '711 fR from the control unit 13.
, a valve actuator that controls the control hydraulic pressure P proportional to the magnitude of the control current value 11 according to the signal (i) and sends the control hydraulic pressure P from the control pressure oil path 44 to the hydraulic boat 35 and the oil chamber 34. , the control current signal (i) is output to the valve solenoid 45 of the electromagnetic proportional pressure reducing valve 46.

In addition, the control oil pressure P and the differential limiting torque T are ToCP-p
--nr-A n; Number of clutches r; Clutch average radius A: There is a relationship between pressure receiving area, and differential limiting torque T is proportional to control oil pressure P.

The control unit h13 uses an in-vehicle microcomputer, and includes an input circuit 131, RAM (random, access, memory) 132, ROM (read,
CPU (central processing unit) 134, clock circuit 135, and output circuit 136.

The input sensors 14 include an anti-skid operation sensor 141, a vehicle speed sensor 142, and an accelerator opening sensor 14.
3 is provided.

The input circuit 131 is a circuit that converts the input signals (b), (V), and (a) from the input sensor 14 into signals that can be processed by the CPU.

The RAM 132 is a readable and writable memory, and input signals from the sensors 141, 142, and 143 are written therein, as well as information during calculation by the CPU 134.

The ROM 133 is a read-only memory in which information necessary for arithmetic processing by the CPU 134 is stored in advance, and is read out by the CPU 134 as needed.

The CPU 134 is a device that performs arithmetic processing on various input information according to predetermined processing conditions.

The clock circuit 135 is a circuit that sets the calculation processing time of the CPU 134.

The output circuit 36 is a circuit that outputs a control current signal (i) to the valve solenoid 45 based on a calculation result signal from the CPU 134.

The anti-skid operation sensor 141 is a sensor that detects whether an anti-skid device installed in the braking system of the vehicle is activated or not, and outputs an anti-skid operation signal (b). A signal of =o is output, and a signal of b=i is output when the anti-skid device is activated.

The vehicle speed sensor 142 is a sensor that detects the vehicle speed and outputs a vehicle speed signal (V) according to the vehicle speed.

The accelerator opening sensor 143 is a sensor that detects the degree of depression of the accelerator pedal and outputs an accelerator opening signal (a) corresponding to the accelerator opening (also referred to as throttle opening).

The vehicle speed sensor 142 and the accelerator opening sensor 143 are used as sensors for searching the control current value 1 from a control characteristic map preset in the control unit 13.

In the ROM 133 of the control unit 13,
As shown in Figure 5, when there is no change in accelerator opening A (
Control characteristic map Ml (accelerator opening differential individual = 0)
Fig. 5 (a)) and control characteristic map M2 when slowly depressing the accelerator pedal (A = 1) (Fig. 5 (a)).
(b))), control characteristic map M3 (Figure 5 (c)) when the accelerator pedal is depressed a little faster (person = 2), and control when the accelerator pedal is depressed quickly (person = 3). A custom map M4 (Fig. 5 (d)) is set.

In addition, each map Ml, M2, M3, Mu is the vehicle speed V
This is a two-dimensional map based on the accelerator opening A and the accelerator opening A. The control current value generally increases as the individual accelerator opening differential increases, and increases in proportion to the vehicle speed V and the accelerator opening A. value.

Next, the operation of the embodiment will be explained.

First, the operation of the differential limiting control will be explained in the sixth section.
This will be explained using the flowchart shown in the figure.

(b) When the anti-skid device is not operating When the anti-skid device is not operating, the operation flow is step 200 → step 201 → step 202 → step 203 → step 204 → step 205 → step 206, and in step 206, the anti-skid device is not activated. Control current signal (
i) is output.

Incidentally, in step 200, the anti-skid operation sensor 141
Step 201 is a step of reading the anti-skid activation signal (b) from the anti-skid activation signal (b) read in step 200, and step 201 is a judgment step of determining whether the anti-skid device is activated or not activated based on the anti-skid activation signal (b) read in step 200. Yes, step 202 is a step of reading the vehicle speed signal (V) from the vehicle speed sensor 142 and the accelerator opening signal (a) from the accelerator opening sensor 143, and step 203 is a step of reading the accelerator opening signal (a) from the accelerator opening signal (a). This is a calculation step in which the accelerator opening differential individual is calculated by differentiating A with respect to time, and step 204 calculates which one of the control characteristic maps M1, M2, M3, and M4 is calculated based on the accelerator opening differential individual calculated in step 203. Step 205 is a selection step in which a control characteristic map is selected, and step 205 is a search step in which a control radio wave value l is retrieved from the control characteristic map selected based on the vehicle speed (2) and the accelerator opening degree A read in step 202.

(b) When the anti-skid device is activated When the anti-skid device is activated, the operation flow is step 200 → step 201 → step 207 → step 206, and in step 206, the differential limiting torque T
A control signal (i) based on the control current value l=O at which the value becomes zero is output.

Note that step 207 is a command step for the control current value i'=0.

As described above, the differential limit control device of the embodiment is configured to control the differential limit torque T to zero and release the differential limit when the anti-skid device is activated, so that the anti-skid device is activated. In some cases, the differential device will not disable the braking control of the anti-skid device or reduce the braking performance of the anti-skid device.

Furthermore, in the embodiment, since a two-dimensional map 7 based on the vehicle speed V and the accelerator opening A is used as the control characteristic map, it is possible to obtain a differential limiting action according to the vehicle speed V and the accelerator opening A. By allowing the accelerator opening differential map to be selected by the individual, a differential limiting action with high responsiveness can be obtained.

Hereinafter, embodiments of the present invention have been described in detail with reference to the drawings, but 1A
The physical configuration is not limited to this embodiment, and the present invention includes any design changes that do not depart from the gist of the present invention.

For example, in the embodiment, the characteristics of a two-dimensional map based on vehicle speed and accelerator opening were shown as the set control characteristics, but other factors such as the road surface friction coefficient and the difference in left and right wheel rotational speeds may also be included.
Alternatively, the map may be set independently to perform differential restriction control corresponding to various vehicle conditions.

Further, in the embodiment, an electromagnetic proportional pressure reducing valve is shown as an actuator, but an example in which an electromagnetic valve that opens and closes or the like may be used to perform hydraulic control by using a control signal as a duty signal may also be used.

(Effects of the Invention) As explained above, in the vehicle differential restriction control device of the present invention, when the anti-skid two-door device is activated, the differential restriction is canceled. When the device is in operation, it becomes a normal differential device with no differential limiting action, thereby providing the effect that the performance of the anti-skid device can always be ensured.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of a claim showing a differential limiting control device for a vehicle according to the present invention, FIG. 2 is a sectional view showing a differential device incorporating differential limiting means of an embodiment of the device of the present invention, and FIG. Figure 2 is a Z-direction arrow view, Figure 4 is a diagram showing the hydraulic pressure generating device and control device installed individually, and Figures 5 (a), (b), (c), and (d) show the control unit of the example device in advance. FIG. 6 is a one-two-dimensional control characteristic diagram of the control current value that is stored, and is a flowchart showing the flow of the differential limiting control operation of the embodiment device. 1... Drive left wheel 2... Drive right wheel 3... Differential means 4... Differential limiting means 5... Input sensor 501... Anti-skid operation sensor 6... Control means

Claims (1)

[Scope of Claims] 1) A differential means for distributing and transmitting engine driving force to left and right drive wheels while allowing a differential, and a drive input section and a drive output section of the differential means, A differential limiting means that generates a differential limiting torque by an external control force, an input sensor that detects a vehicle state, and a control device that outputs a control signal that increases or decreases the differential limiting torque based on an input signal from the input sensor. In the vehicle differential limiting control device, the input sensor includes an anti-skid operation sensor that detects activation/non-operation of an anti-skid device provided in the braking system, and the control means is configured to control the operation of the anti-skid device. A differential limiting control device for a vehicle, characterized in that the differential limiting control device for a vehicle is configured as a means for performing control to sometimes cancel differential limiting.