JPS62191226A - Driving system clutch device for vehicle - Google Patents

Abstract

PURPOSE:To increase a pump discharge pressure even when a steering operation is not carried out and utilize a power steering pump for generating fluid pressure by using a power steering oil pressure on the upper course side of a throttle means as the fluid pressure for a driving system clutch means. CONSTITUTION:A throttle means 501 is provided in between a power steering pump 7 and a power steering control valve 8, as a fluid pressure generating means 5. And, a fluid pressure passage 502 is connected to a power steering pressure oil passage 9 on the upper course side of the throttle means 501, to use a power steering oil pressure P as a clutch fluid pressure Pc for a driving system clutch means 4 via a fluid pressure control means 6. Thereby, a pump discharge pressure can be increased to a defined pressure by the throttle means 501 even when a power steering operation is not carried out, eliminating the need for newly adding a hydraulic pump as a fluid pressure generating means 5, while enabling the power steering pump 7 to be used as the fluid pressure generating means 5.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a differential limiting clutch that is used in a differential device, a transfer device of a four-wheel drive vehicle, etc., and which applies clutch engagement force using external fluid pressure. The present invention relates to vehicle drive system clutch devices such as drive force distribution clutches and drive force distribution clutches.

(Prior Art) Conventional limited differential clutch devices for vehicles include, for example,
A device as described in Japanese Utility Model Application Publication No. 59-68846 is known.

This conventional device includes an operating means provided in the driver's cab, a hydraulic pressure generating device that generates hydraulic pressure by operating the operating means, and a hydraulic pressure generator that receives the hydraulic pressure generated by the hydraulic generating device and presses the side gear of the differential against the differential case. and an actuator device that acts on the differential case, and the differential limiting force of the differential device is changed by changing the pressing force of the side gear against the differential case in accordance with the hydraulic pressure generated by the hydraulic pressure generating means. It was something.

(Problems to be Solved by the Invention) However, in such conventional devices, the driver operates the operating means according to his preference or judgment of the road surface condition, converts the operating force into hydraulic pressure, and applies the differential limiting force. Therefore, in order to obtain a high differential limiting force, a very large operating force was required, and if the operating means were to be abolished, a new hydraulic pressure generator was required. There was a problem in that a motor-driven hydraulic pump had to be installed as a device.

Therefore, it is possible to use the existing power steering pump in the vehicle as a hydraulic pressure generator, but even if you try to use the power steering hydraulic pressure as it is, the pump discharge pressure is low when the steering is not being operated, It could not be used as a hydraulic generator.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and in order to achieve this purpose, the present invention has adopted the following solving means. .

The solution of the present invention will be described with reference to the claim conceptual diagram shown in FIG. A drive system clutch means 4 is provided between the drive output section and the drive output section and generates a clutch engagement force using external fluid pressure; A vehicle drive system clutch device comprising: a fluid pressure control means 6 which sets P to a control fluid pressure Pc to the drive system clutch means 4; 8 and a fluid pressure passage 502 connected to the power steering pressure oil passage 9 on the upstream side of the throttle means 501.

(Function) Therefore, in the vehicle drive system clutch device of the present invention, as described above, by using the power steering hydraulic pressure obtained upstream of the throttle means as the clutch fluid pressure of the drive system clutch means, The pump discharge pressure can be increased to a predetermined pressure by the throttling means even when the steering operation is not being performed, and the power steering pump can be used as a fluid pressure generating means without adding a new hydraulic pump as a fluid pressure generating means. be able to.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In describing this embodiment, a differential limiting clutch device for an automobile including differential limiting clutch means operated by external hydraulic pressure will be taken as an example.

First, the configuration of the first embodiment will be explained.

As shown in FIGS. 2 to 4, the embodiment device includes a differential device (power split device) 10, a multi-disc friction clutch means (drive system clutch means) 11, a power steering device 40, a hydraulic pressure generator (fluid It is equipped with a pressure generating means) 50 and a hydraulic control device (fluid pressure control means) 60, and 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.
It 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 manually applied.

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 gear 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 within the housing 16 and differential case 18, and includes a multi-disc friction clutch 27.27', a pressure ring 28.28', and a reaction plate 29.2.
9', thrust bearing 30.30', spacer 31.3
1', a push port/end 32, a hydraulic piston 33, an oil chamber 34, and a hydraulic port 35.

The multi-plate friction clutch 27.27' has 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'. It is composed of friction disks 27b and 27'b, and pressure rings 28 and 28' are provided on both axial end faces.
and reaction play) 29, 29' are arranged.

The pressure ring 28, 28' is connected to the pinion mate shaft 19 as a member that receives the clamping force.
As shown in FIG. 3, the fitting part is fitted to the shaft end 19a with a square cross section through the square grooves 28a and 2B'a, and the torque proportional differential It has a structure that does not generate thrust force due to rotational differences like a motion limiting mechanism.

The hydraulic piston 33 moves in the axial direction (rightward in the drawing) by hydraulic pressure supplied to the hydraulic port 35.

Both multi-disc friction clutches 27 and 27' are engaged according to the oil pressure level, and one multi-disc friction clutch 27 is
The fastening force is transmitted from the bushing rod 32 to the spacer 31 to the thrust bearing 30 to the reaction plate 29, and the pressure ring 28 is used to receive the reaction force, and the other multi-plate friction clutch 27' receives the fastening reaction force from the housing 16. becomes the tightening force and is tightened.

The power steering device 40 is a device that power-assists the steering force using hydraulic pressure during steering operation, and includes a power steering pump 41, a power steering control valve 42, and a power steering pressure oil passage 43.

The power steering pump 41 is a pump that operates by obtaining driving force from an engine, and is connected to a reserve tank 44 through a suction oil passage 45, and is connected to the control valve 4.
2 through a power steering pressure oil passage 43.

The power steering control/help 42 includes:
This valve is switched by steering operation, and is connected to the reserve tank 44 through a drain oil passage 46.

The hydraulic pressure generating device 50 is a device that generates clutch supply hydraulic pressure to be supplied to the multi-disc friction clutch means 11, and includes a fixed orifice (throttle means) 51, a branch oil path (fluid pressure path) 52
, check valve 53, accumulator 54. A supply pressure oil passage 55 is provided.

The fixed orifice 51 is a throttling means that is provided in the middle of the power steering pressure oil passage 43 of the power steering device 40 and has a constant throttling amount.

The branch oil passage 52 is connected to the power steering pump 4.
The pump discharge pressure P is connected to the power steering pressure oil line 43a between the discharge port 41a of No. 1 and the fixed orifice 51, and is increased due to the line resistance due to the fixed orifice 51.
This is an oil passage that guides the hydraulic oil. - The check valve 53 is provided in the middle of the branch oil passage 52, and has the function of regulating the flow direction of the hydraulic oil in one direction and maintaining the oil pressure level on the supply pressure oil passage 55 side.

The accumulator 54 is provided at the end of the supply pressure oil passage 55 and is connected to the branch oil passage 52 and the check valve 53.
This is a pressurized hydraulic oil storage means for storing hydraulic oil at a predetermined pressure that has passed through the above period, and preparing a system for supplying hydraulic oil at a controlled hydraulic pressure Pc to the multi-disc friction clutch means 11.

The hydraulic control device 60 converts the clutch supply hydraulic pressure from the supply pressure hydraulic line 55 into a control hydraulic pressure Pc according to predetermined control conditions, and converts the clutch supply hydraulic pressure from the supply pressure hydraulic line 55 into a control hydraulic pressure Pc, and controls the multi-disc friction clutch means 1 which is a differential limiting clutch.
This device is for controlling the amount of differential restriction according to 1, and is equipped with a vehicle speed sensor 61 and an accelerator opening sensor 62 as input means, a control unit 65 as a control means, and an electromagnetic proportional solenoid valve 66 as a control actuator.
It is equipped with

The vehicle speed sensor 61 generates a vehicle speed signal (V) according to the vehicle speed V.
This is a sensor that outputs .

The accelerator opening sensor 62 is a sensor that outputs an accelerator opening signal (a) corresponding to the accelerator opening A.

The control unit 65 uses an electronic control circuit such as a microcomputer or the like, and inputs the signals (v) and (a) from both the sensors 61 and 62, and changes the accelerator opening (1). = dA/d t) and a preset control characteristic map (Figures 6 and 7), the control current signal (i) at a predetermined TL current value i is converted into an electromagnetic proportional This circuit provides output to the valve solenoid 66a of the solenoid valve 66.

The electromagnetic proportional solenoid valve 66 determines the amount of drain oil to the drain oil path 67 by the force balance between the electromagnetic force from the valve solenoid 66a and the oil pressure from the signal pressure oil path 66b, and determines the amount of drain oil to the control pressure oil path 68. A valve that adjusts the pressure of hydraulic oil to a predetermined control oil pressure Pc, as shown in Fig. 8.
The higher the current value i for the valve solenoid 66a, the
A high control oil pressure Pc can be obtained.

Next, the operation of the first embodiment will be explained.

(a) Hydraulic pressure generation function First, the hydraulic pressure generation function of the hydraulic pressure generating device 50 of the embodiment will be explained.

Power steering pump 4 for engine speed N
The pump discharge flow rate Q of No. 1 exhibits the characteristics shown in FIG. 5(A), and when the engine speed N is N1≦N≦N2,
In order to secure the power assist force when parking or turning around a curve at low speed, the pump discharge flow rate Q increases and N
> In N3, the vehicle speed is high and high power assist force is not required, so the pump discharge flow rate Q is slightly lower (engine rotation sensitive power steering device).

Therefore, the pump discharge pressure P in the power steering pressure oil passage 43a when there is no fixed orifice 51 is as shown in FIG.
), and the pressure level P is low due to the back pressure corresponding to the overall pipe resistance of the power steering device 40.
It becomes a.

However, in the embodiment, since the fixed orifice 51 is provided in the power steering pressure oil passage 43 between the discharge boat 41a of the power steering pump 41 and the power steering control valve 42, the flow rate is throttled by the fixed orifice 51. Pump discharge pressure P increases,
The hydraulic characteristics become as shown in FIG. 5CB), and the pressure level becomes a pressure level Pb higher than the pressure level Pa when the fixed orifice 51 is not provided.

In this way, in the hydraulic pressure generator 50 of the embodiment, the hydraulic oil at least at the pressure level Pb can be stored in the accumulator 54 after passing through the check valve 53, and
Hydraulic oil having at least a pressure level pb can be supplied from the supply pressure oil passage 55 to the electromagnetic proportional solenoid valve 66.

Incidentally, the pump discharge pressure P is determined by the line resistance of the power steering device 40, so when the power assist force is generated during steering operation, the pressure level of the pump discharge pressure P is set to the above-mentioned level due to the load resistance. It becomes higher than the pressure level Pb.

(b) Hydraulic control action Next, the hydraulic control action by the hydraulic control bag: a6O of the embodiment, that is, the control action of the differential limiting amount, will be explained with reference to a flowchart showing the flow of the control action shown in FIG.

The flow of the differential limiting control operation proceeds from step 100 to step 101 to step 102. In step 102, the set accelerator opening α and the accelerator opening change are compared in magnitude, and O≦A α. Then, the process proceeds from step 103 to step 104, and the control characteristic map M shown in FIG.
1, the current value i is looked up from the vehicle speed V and the accelerator opening degree A detected by the sensor, and the control current signal (i
) is output to the valve solenoid 66a.

Further, when the accelerator opening degree change rate A is A≧α, the process proceeds from step 105 to step 106, and the control characteristic map M2 shown in FIG. 7 (output gain is higher than the map Ml) and the vehicle speed V detected by the sensor. A current value i* is looked up in a table from the accelerator opening degree A, and a control current signal (i) based on the table looked up current value it is output to the valve slide/id 66a.

Further, when the accelerator opening degree change is AO, the process proceeds to step 107, and a control current signal (i) with a current value i''=o is output.

The relationship between the torrent flow value i* and the control oil pressure Pc is as shown in the oil pressure characteristics in Figure 8, and the higher the current value 18, the higher the control oil pressure Pc, and the higher the control oil pressure Pc. This means that the amount of differential restriction also increases.

In this way, the higher the vehicle speed V and the higher the accelerator opening A, the larger the differential restriction amount becomes, and high-speed straight-line stability can be ensured.

In addition, when the accelerator opening change rate A, that is, the speed at which the accelerator pedal is depressed, is high, the output gain is increased as shown in the control characteristic map M2, so that when driving during sudden acceleration or starting, etc. Stability can be ensured.

Further, when turning by steering operation, the hydraulic pressure generated by the hydraulic pressure generating device 50 increases in accordance with the steering resistance from the wheels, so that a differential restriction amount corresponding to the lateral acceleration can be obtained during turning.

As explained above, in the differential limiting clutch installation for an automobile according to the first embodiment, the power steering hydraulic pressure obtained upstream of the fixed orifice 51 is used as the clutch control pressure of the multi-disc friction clutch means 11. As a device, the pump discharge pressure can be increased to the predetermined pressure pb by the fixed orifice 51 even when the steering operation is not performed, and the power steering pump 41 can be used without adding a new hydraulic pump as a hydraulic pressure generating means.
can be used as a hydraulic pressure generating means.

Further, in the first embodiment, the hydraulic pressure generating device 50 is provided with the check valve 53 and the accumulator 54, so that
Even when a predetermined pressure of hydraulic pressure is suddenly required, such as when starting or suddenly accelerating, the hydraulic pressure supply system can be maintained.

Next, a second embodiment shown in FIG. 10 will be described.

In this second embodiment, the throttle means provided in the middle of the power steering pressure oil passage 43 is arranged in the power steering device 4.
In this example, the solenoid 56a is used in place of the fixed orifice 51 in the first embodiment to prevent this from occurring, as this may result in conduit resistance and cause a delay in the generation of the power assist force during steering. This is an example in which a variable orifice 56 that is operated by is provided, and a pressure switch 63 is provided in the supply pressure oil passage 55 as an input means for switching the variable orifice 56 between a constricted state and an open state.

Note that the other configurations are the same as those in the first embodiment, so the same reference numerals are used in the drawings and explanations thereof will be omitted.

Functionally, when the pressure of the accumulator 54 falls below a predetermined pressure, the pressure switch 63 is turned ON, and the control unit 65 that receives this ON signal outputs an operation command signal to the solenoid 56a to throttle the flow path. .

Conversely, when the pressure in the accumulator 54 exceeds a predetermined pressure, the pressure switch 63 turns OFF, and the control unit 65 inputting this OFF signal outputs the solenoid 6.
An operation command signal for opening the flow path is output to 5a.

Therefore, the supply pressure line of the electromagnetic proportional solenoid valve 66 is always maintained at a constant pressure, and the variable orifice 5
6, the influence of the throttle on the power steering device 40 can also be eliminated.

Note that other operations are the same as those in the first embodiment, so description thereof will be omitted here.

Next, a third embodiment shown in FIGS. 11 and 12 will be described.

This 53 embodiment has the same basic configuration as the second embodiment, but a pressure switch 6 is used as an input means for switching the variable orifice 56 between the constricted state and the open state.
In addition to 3, this is an example in which a steering angle sensor 64 (FIG. 11 is a characteristic diagram of the operating angle sensor) that detects the steering angle θ and outputs a steering angle signal (0) is added.

Operationally, the steering angle signal (0) from the steering angle sensor 64
When the steering angle θ is equal to or greater than the set steering angle Oo, or when the steering angular velocity 6 (=dθ/dt) is equal to or greater than the set steering angular velocity 00, the pressure in the accumulator 54 is equal to or less than the predetermined pressure, and the variable orifice 56 This is an example in which the variable orifice 56 is kept open even in the throttled state to give top priority to the power assist action of the power steering device 40.

As a result, in this third embodiment, a power assist force that does not change the hydraulic response during steering can be obtained, and the steering feeling can be kept constant. .

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may be modified without departing from the gist of the present invention. included.

For example, in the embodiment, a differential device was shown as an example of a power split device, but it can also be applied to a transfer device used as a drive force distribution device in a four-wheel drive vehicle, and the drive system clutch in this case is a differential device. A variable torque clutch is used to make the torque variable.

Further, in the embodiment, an example of hydraulic control based on vehicle speed and accelerator opening degree has been shown, but hydraulic control may also be performed based on the coefficient of road friction, the rotational speed difference between the left and right wheels or the front and rear wheels, etc.

(Effects of the Invention) As explained above, in the vehicle drive system clutch device of the present invention, there is a means for using the power steering hydraulic pressure obtained upstream of the throttle means as the clutch fluid pressure of the drive system clutch means. Therefore, the pump discharge pressure can be increased to a predetermined pressure using the throttling means even when the steering operation is not being performed, and the power steering pump can be used as a fluid pressure generating means without adding a new hydraulic pump as a fluid pressure generating means. The effect is that it can be used.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of a claim showing a vehicle drive system clutch device of the present invention, FIG. 2 is a sectional view showing a differential device to which the differential limiting clutch device of an embodiment of the present invention is applied, and FIG. FIG. 4 is a diagram showing the differential limiting clutch device of the first embodiment, FIG. 5 (A) and (B) are characteristic diagrams of pump discharge flow rate and pump discharge pressure with respect to engine speed, Figures 6 and 7 are diagrams showing control characteristic maps stored in advance in the control unit, Figure 8 is a hydraulic characteristic diagram showing the relationship between the current value from the control unit and the control oil pressure, and Figure 9 is a diagram showing the control characteristic map stored in the control unit in advance. A flowchart diagram showing the flow of hydraulic control operation in the unit, Fig. 10 is a diagram showing the differential limiting clutch device of the second embodiment, and Fig. 11 is a sensor signal characteristic diagram of the steering angle sensor used in the third embodiment. , FIG. 12 is a diagram showing a differential limiting clutch device of a third embodiment. 1.2... Drive wheel 3... Power split device 4... Drive system clutch means 5... Fluid pressure generation means 6... Fluid pressure control means 7... Power steering pump 8... Power steering control valve 9...
・Power steering pressure oil passage 501... Throttle means 502... Fluid pressure passage 0≦person<(I MI
A≧a MaFigure 8

Claims (1)

[Claims] 1) A power split device that distributes and transmits engine driving force to front and rear or left and right drive wheels, and a power split device that is provided between a drive input section and a drive output section of the power split device, and that is provided with an external fluid source. A drive system clutch means that generates a clutch engagement force by pressure, and a fluid pressure control means connected to the drive system clutch means and that uses fluid pressure from the fluid pressure generation means as a control fluid pressure for the drive system clutch means. In the vehicle drive system clutch device, the fluid pressure generating means is connected to a throttle means provided between a power steering pump and a power steering control valve, and a power steering pressure oil path upstream of the throttle means. A clutch device for a vehicle drive system, characterized in that the clutch device is a clutch device for a vehicle drive system. 2) The vehicle drive system clutch device according to claim 1, wherein the throttle means is a variable throttle means that opens when the steering angle or the steering angular velocity is equal to or higher than a predetermined value.