JPH0531308Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a differential limiting device used in automobiles and the like.

[Prior art]

Generally, a differential device is installed in automobiles to compensate for the difference in rotational speed between the inner and outer wheels when changing direction, but due to the nature of the differential device, if one wheel falls into mud, etc. There was a problem in which only the wheels on the muddy side, where the coefficient of friction is low, would spin, and the other wheel would lose its driving force, making it difficult to escape.

Conventionally, as a measure to eliminate the above-mentioned problems, a differential system was developed in which the relative rotation that occurs when one wheel is idling is detected, and the action of the differential is limited by a friction clutch, etc., so that torque is transmitted to the other wheel. Limiting devices are known.

The detection means for turning on and off the differential limiting device is
For example, as seen in JP-A-58-178040, there is a pair of left and right rotation sensors that detect the rotation of the left and right axles, a rotation sensor that detects the rotation of the drive shaft, and a position sensor that detects the position of the tie rod. It is composed of arithmetic processing means that arithmetic processes the output signals output from each sensor and outputs a command signal, and has a structure including a plurality of sensors.

[Problem that the invention attempts to solve]

In such a differential limiting device, in particular, rotation sensors that detect the rotation speed of the left and right axles are installed independently on the left and right sides, so it is necessary to secure a space for installing each sensor. , there is a risk that the case will become larger, and there may be restrictions on the mounting position. In addition, since the rotational speed of the left and right axles is detected by independent rotation sensors, it is expensive, and if there are many sensors, the failure rate increases, and it also reduces workability. It was undesirable. Therefore, this idea reduces the number of rotation sensors, and
It is an object of the present invention to provide a differential limiting device that can provide the same detection function as the conventional one.

[Means for solving problems]

In order to achieve the above object, this invention was constructed as follows. That is, a limiting means for limiting the function of a differential device that allows differential movement between the left and right axles of a vehicle such as an automobile by the operation of an actuator, and a limiting means provided on either one of the left and right axles to detect the rotation speed of the axle. a first rotation sensor; a second rotation sensor that detects the rotation speed of a drive shaft that is powered by the engine of the vehicle and drives the differential; and a second rotation sensor that is based on signals output from the first and second rotation sensors. The rotation difference between the left and right axes can be calculated using the following formulas (1) and (2).
a calculation processing means that performs calculation processing, a reference setting calculation means that calculates and determines a reference set value as a reference value for the rotation difference between the left and right axles during the vehicle based on the position of the tie rod, etc.; and a reference output from the reference setting calculation means. Comparison processing means compares a set value and an output signal from the arithmetic processing means and operates the actuator when the output signal from the arithmetic processing means is larger than the reference set value. restriction device.

ωL=ωS×2/k−ωR ……(1) Δω=｜ωR−ωL｜ …(2) here, ωL…Left axle rotation speed ωS…Drive shaft rotation speed ωR…Right axle rotation speed K...Final reduction ratio It is.

〔Example〕

Hereinafter, one embodiment of this invention will be described in detail with reference to the drawings.

A pinion gear 5 is rotatably fitted into a pinion shaft 3 near the center of a differential case 1 (hereinafter referred to as a differential case) and is rotatable while revolving together with the shaft 3.

Side gears 7 on the left and right sides of this pinion gear 5 are arranged and mesh with the pinion gear 5. Output shafts 9 and 11 are fitted into the side gears 7, respectively, and one output shaft 9 is connected to a left wheel (not shown), and the other output shaft 11 is connected to a right wheel (not shown).

A ring gear 17 is attached to the differential case 1, which meshes with a drive shaft 15 leading to the engine side.
It is driven and rotated by a drive shaft 15. Furthermore, a multi-plate friction clutch 13 is incorporated between the differential case 1 and the side gear 7 as differential limiting means.

A half 19 of the friction plates of the friction clutch 13 is locked to the differential case 1 side so as to be movable in thrust, and the remaining half 21 is locked to the side gear side so as to be movable in thrust, and they are arranged alternately.
A pressure ring 23 that presses and moves these friction plates 19 and 21 to bring them into contact with each other to thereby engage the friction clutch 13 is arranged near the end face of the group of friction plates that is closer to the outside of the differential case 1. Further, a back ring 25 is provided near the end surface of the friction plate group opposite to the end surface, that is, the end surface closer to the center of the differential case 1.

A ring-shaped piston 33 is fitted in a ring-shaped groove formed on the inner surface of the carrier 31 at a position facing the pressure ring 23 via a seal 35 so as to be watertight and slidable. Behind the piston 33 is a passage 37 for the working fluid of the piston 33.
is provided in the carrier 31, and the passage 37 communicates with the outlet of the hydraulic pump P via a connector member 39 attached to the outer surface of the carrier 31. Note that M indicates a drive motor.

On the other hand, a thrust roller bearing 41 is provided between the front surface of the piston 33 and the pressure ring 23.
A ring-shaped connecting member 43 that rotates with the differential case 1 via the ring-shaped connecting member 43 and is capable of thrust movement, and several connecting spindles 44 arranged on the circumference of the back surface thereof are placed. The connecting member 43 and the connecting spindle 44 are integrated with the pressure ring 23 by a spring pin or the like, so that the piston movement of the piston 33 can be smoothly transmitted to the pressure ring 23 rotating together with the differential case 1. It's summery. The thrust roller bearing 41 has an inner retainer rotatably secured to an annular protrusion 45 provided on the inner circumference of the contact surface of the connecting member 43.

The piston 33, thrust roller bearing 41, connecting member 43, connecting spindle 44, and drive motor M constitute an actuator 47 that drives the pressure ring 23.

The actuator 47 includes first and second rotation sensors 49 and 51, an arithmetic processing means 53, and a control means 5.
9.

The first rotation sensor 49 is composed of, for example, a detection section 57 provided on the carrier 31 and a rotating disk 55 provided with a slit 55a provided on the right axle 11, and measures the speed at which the slit 55a crosses the detection section 57. This detection serves as a means for determining the rotational speed of the axle 11.

The second rotation sensor 51 includes, for example, a detection section 57 provided on the carrier 31 and a rotating disk 55 provided with a slit 55a provided on the drive shaft 15, and detects the speed at which the slit 55a crosses the detection section 57. By doing so, it becomes a means for determining the rotational speed of the drive shaft 15.

The calculation processing means 53 calculates the rotation speed of the left axle 9 based on the signals output from the first and second rotation sensors 49 and 51, and then performs calculation processing to compare the rotation speeds of the left and right axles 9 and 11. Data is entered.

The rotation speed ωL of the left axle 9 is determined by the equation ωL=ωs×2/k−ωR. Also, differential rotation speed (rotation difference between left and right axles) Δω
is determined by the formula Δω=|ωR−ωL|.

In addition, ωL…Left axle rotation speed ωs…Drive shaft rotation speed ω…Right axle rotation speed Δω…Differential rotation speed N...Reference setting value k...Final reduction ratio It is.

The output signal processed by the arithmetic processing means 53 is then input to the comparison processing means 59. On the other hand, the position of the tie rod is detected by the position detection unit 60, and the detected value is received by the reference setting value calculation means 61, and the position of the tie rod, that is, the steering angle, is determined based on the position of the tie rod, that is, the steering angle. A reference setting value as a reference value of the rotational difference is calculated and determined, and a signal of the reference setting value N is output to the comparison processing means 59.

The comparison processing means 59 compares the reference set value N with the signal from the arithmetic processing means 53, and if the signal from the arithmetic processing means 53 is large, the actuator 47
It functions to output a command signal that activates the

In addition, as a method of determining the reference set value N at this time, calculation can be performed based on, for example, a position detection signal output from the tie rod, the drive shaft rotational speed ωs, etc.

Next, the operation will be explained based on the flowchart shown in FIG.

During traveling in step 1, the rotational speed of the right axle 11 and drive shaft 15 is the same as that in steps 2 and 3.
It is read in In step 4, the rotation speed ωL of the left axle 9 is calculated from the rotation speed ωR・ωs of the right axle 11 and the drive shaft 15.
is required. Next, in step 5, the differential rotation speed Δω is determined. In step 6, a reference set value N is calculated, and then in step 7, when it is determined that the differential rotation speed Δω is smaller than the set value N, the process returns to step 2 and the above steps are repeated.

On the other hand, slipping occurred on one wheel and the reference setting value N
If it is determined that the differential rotation speed Δω is larger than that, differential restriction is activated in step 8, and torque is transmitted to the left and right axles. Differential restriction then operates until the slip is released. (Step 9) Note that the second rotation sensor 51 that detects the number of rotations of the drive shaft 15 is connected to a sensor that is generally installed in an automobile as a fuel injection control sensor that controls fuel injection or a vehicle speed detection sensor. By using this, the only new sensor that needs to be provided is the first rotation sensor provided on the right axle. It is also possible for the actuator to be of the electromagnetic clutch type.

[Effect of idea]

As explained above, according to the differential limiting device of this invention, the differential limiting function of the differential device can be accurately differentially controlled by the signals from the first and second rotation sensors.

Furthermore, since the number of sensors, that is, the number of sensor locations is reduced, the incidence of failure can be held down to a corresponding degree, and it is advantageous in terms of installation space. Moreover, it greatly contributes to reducing the cost. It is also very favorable in terms of workability.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of the defrock device of this invention, FIG. 2 is an overall schematic diagram showing the defroc device of this invention, and FIG. 3 is a flowchart. Explanation of main drawing symbols, 9, 11... Left and right wheels, 13... Multi-plate friction clutch (limiting means),
15... Drive shaft, 47... Actuator, 49
...first rotation sensor, 51...second rotation sensor,
53... Arithmetic processing means, 59... Comparison processing means.

Claims (1)

[Scope of Claim for Utility Model Registration] A limiting means for limiting the function of a differential device that allows differential movement between the left and right axles of a vehicle such as an automobile by the operation of an actuator, and an axle provided on either one of the left and right axles. a first rotation sensor that detects the rotation speed of a drive shaft that is transmitted with power from the engine of the vehicle and drives the differential device; A calculation processing means that calculates the rotation difference between the left and right axles using the following formulas (1) and (2) based on the output signal, and a reference value for the rotation difference between the left and right axles at the time of driving based on the position of the tie rod, etc. A reference set value calculating means for calculating and determining a set value, and a reference set value outputted from the reference set value calculating means and an output signal from the arithmetic processing means are compared, and an output signal from the arithmetic processing means is determined as the reference set value. and comparison processing means for operating the actuator when the differential is greater than a set value. ωL=ωS×2/k-ωR ……(1) Δω=｜ωR-ωL｜ ……(2) Here ωL…Left axle rotation speed ωS…Drive shaft rotation speed ωR…Right axle rotation speed K…Final deceleration It is a ratio.