JPH0611217Y2 - Drive system clutch controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a drive system clutch control such as a transfer clutch used for front and rear wheel drive force distribution control and a differential limiting clutch used for left and right wheel differential limiting amount control. Regarding the device.

(Prior Art) In the application specification and drawings of Japanese Patent Application No. 61-109868 (filed on May 14, 1986), the present applicant has proposed a transfer clutch control device as prior art.

In this prior device, a multi-plate friction clutch that is engaged by external hydraulic pressure is shown as the transfer clutch,
In this multi-disc friction clutch, initial pressure is applied in a region where the front-rear wheel rotational speed difference is small, and the clutch hydraulic pressure is increased as the front-rear wheel rotational speed difference increases.

By applying this initial pressure, running stability is enhanced during high-speed straight running with little difference in rotational speed,
Control responsiveness is also enhanced.

(Problems to be solved by the invention) However, in such a prior art device, the electric motor of the clutch hydraulic pressure generating means is always in a rotating state when the engine is driven regardless of whether the vehicle is stopped or running, and thus the power consumption is reduced. In addition, the volume of the electric motor will increase and the noise of the electric motor and the hydraulic pump will be relatively annoying because the electric motor is rotated and the hydraulic pump is driven even when the vehicle is stopped when the indoor noise is low. It left a problem.

On the other hand, a clutch hydraulic pressure generating means that has an electric motor, a hydraulic pump, an accumulator, and a control valve, and turns the electric motor on and off by monitoring the accumulator hydraulic pressure is used, and the electric motor is turned off when the accumulator hydraulic pressure is high. Therefore, there is a plan to reduce the power consumption, but since the initial pressure was applied only by the condition of the rotational speed difference, the initial pressure will be applied even when the vehicle is stopped due to a signal stop, etc. As a result, the frequency of turning the electric motor is increased, and the above problems cannot be solved.

That is, as shown in FIG. 6, as long as the clutch hydraulic pressure Pc is generated, the drain amount ΔV, which is a leakage of hydraulic oil, is generated, so that the accumulator pressure decreases even when the initial clutch hydraulic pressure Pc ₀ is applied when the vehicle is stopped. Therefore, the operating frequency of the electric motor increases.

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

The solution means of the present invention will be described with reference to the conceptual diagram of the claims shown in FIG. 1. The drive system clutch means 1 is provided in the middle of the engine drive system for transmitting the engine drive force to the wheels and is engaged with the clutch hydraulic pressure from the outside. Connected to the drive system clutch means 1, the electric motor 201, the hydraulic pump 20
2, having an accumulator 203 and a control valve 204, turning on the electric motor 201 by monitoring the accumulator oil pressure,
Clutch oil pressure generation means 2 that is turned off, vehicle stop detection means 301 that detects whether the vehicle is stopped, start operation detection means 302 that detects the presence or absence of a start operation by the driver, and the running state of the vehicle are detected. Based on the detection signals from the traveling state detecting means 303 and the detecting means 3, when the vehicle is stopped and the signal indicating the start operation is not output, the clutch hydraulic pressure of the drive system clutch means 1 is set to zero, and the vehicle is stopped. And a signal indicating a start operation is output, the clutch pressure control means 4 applies an initial pressure to the drive system clutch means 1 and applies a clutch hydraulic pressure to the drive system clutch means 1 in accordance with a running state when the vehicle is running.
And are provided.

(Operation) In the drive system clutch control device of the present invention, the clutch control means 4 for inputting the detection signals from the vehicle stop detection means 301, the start operation detection means 302, and the traveling state detection means 303 causes the start operation when the vehicle is stopped. Is not output, the clutch hydraulic pressure of the drive system clutch means 1 is zero, and when the vehicle is stopped and a signal indicating a start operation is output, an initial pressure is applied to the drive system clutch means 1. When the vehicle is traveling, clutch hydraulic pressure is applied to the drive system clutch means 1 according to the traveling state.

Therefore, when the vehicle is stopped, the clutch control is changed depending on whether the vehicle is in a non-starting operation or in a starting operation, the clutch hydraulic pressure is set to zero in the non-starting operation, and the initial pressure is applied in the starting operation. When low power consumption and low noise are achieved when the vehicle is stopped without any operation and then the vehicle is moved from the stopped state, the straight running stability and the control response are improved.

Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings. In describing this embodiment, a drive force distribution control device for a four-wheel drive vehicle based on rear wheel drive will be taken as an example.

First, the configuration of the embodiment will be described.

A four-wheel drive vehicle to which the driving force distribution control device (clutch control means) A of the embodiment is applied has an engine 10, a transmission 11, a transfer input shaft 12, a rear propeller shaft 13, a rear differential, as shown in FIG. 14, rear drive shaft 15, 16, rear wheel 1
7, 18, multi-plate friction clutch (drive system clutch means) 1
9, gear train 20, front propeller shaft 2
1, a front differential 22, front drive shafts 23 and 24, and front wheels 25 and 26.

The multi-plate friction clutch 19 and the gear train 20 are built in the transfer device 30, and the driving force from the engine 10 is transmitted to the rear wheels 17 and 18 by direct connection. From the rear wheel drive system, the multi-plate friction clutch 19 and the gear train are transmitted. Two
The driving force is distributed and transmitted to the front wheels 25, 26 via 0.

That is, since the multi-plate friction clutch 19 is engaged by the clutch hydraulic pressure Pc from the outside, the higher the clutch hydraulic pressure Pc, the higher the distribution of the driving force to the front wheels 25, 26 side.

For the specific structure of the transfer device 30, see, for example, FIG. 3 of Japanese Patent Application No. 61-109868 cited in the prior art.

As shown in FIG. 3, a clutch hydraulic pressure generating device (clutch hydraulic pressure generating means) 40 as an external device for applying a clutch hydraulic pressure Pc to the multi-plate friction clutch 19 includes a hydraulic pump 41, a primary pressure pipe 42, and A valve 43, an accumulator 44, a pressure switch 45, an electromagnetic proportional pressure reducing valve 46, a secondary pressure (control pressure) pipe 47, and a drain pipe 48 are provided.

The hydraulic pump 41 is driven by an electric motor 49. By monitoring the accumulator pressure by a pressure switch 45, the electric motor 49 is turned off when the accumulator pressure is equal to or higher than a predetermined pressure, and the electric motor 49 is turned on when the accumulator pressure is lower than the predetermined pressure. Turn it on.

As shown in FIG. 4, the electromagnetic proportional pressure reducing valve 46 includes a spool 46b that reciprocates in the valve hole 46a, a spring 46c and a check oil passage 46d that generate a force in the right direction of the drawing with respect to the spool 46b. The spool 46b
And a solenoid 46e for generating a force in the left direction in the drawing in accordance with the magnitude of the command current value i.
Of the left-right force applied to the solenoid, that is, the solenoid 4
The clutch hydraulic pressure Pc depends on the magnitude of the command current value i to 6e.
Is determined.

As shown in FIG. 6, when the electromagnetic force by the command current value i to the solenoid 46e does not reach the biasing force by the spring 46c, the spool 46c is at the position indicated by the dotted line, and the hydraulic pump 41 and accumulator 44 Primary pressure P1
Is blocked and the drain amount ΔV disappears, but the command current value i
The drain amount .DELTA.V increases with increasing (especially when the command current value i is dithered).

The driving force distribution control device A is a device for controlling the clutch pressure Pc of the multi-disc friction clutch 19 by a control command based on an electric signal.

This driving force distribution control device A is provided with a front wheel rotation speed sensor 51, a rear wheel rotation speed sensor 52, a clutch switch 53, a proportional constant setting means 54, an ignition switch 55 as input sensors, and a microcomputer as a control module. A control unit 56 having a central circuit configuration is provided, and the electromagnetic proportional pressure reducing valve 46 for controlling the clutch hydraulic pressure Pc according to the command current value i is provided as a control actuator.

As shown in FIG. 5, the control unit 56 includes a straight traveling region R in which the rotational speed difference ΔN is around zero.
In (including gentle curve traveling), the initial command current value i ₀ is set to a constant value, and the rotation speed difference Δ
The command current value i increases as N increases toward the + side, and when the rotational speed difference ΔN exceeds the predetermined value ΔN1, the command current value i is rapidly increased.

In addition, in the tight corner braking phenomenon occurrence region B where the rotational speed difference ΔN is on the negative side, the command current value i is gradually reduced to zero with a predetermined inclination, and
When returning from the rotational speed difference ΔN due to a large negative value in the direction of ΔN = 0, a predetermined hysteresis is provided to gradually increase the command current value i to the initial command current value i ₀ .

The clutch hydraulic pressure Pc and the transmission torque ΔT to the front wheels are in a proportional relationship as shown in FIG. 7.

Next, the operation of the embodiment will be described.

First, the flow of the control operation in the driving force distribution control device A in the embodiment that starts when the ignition switch 55 is turned on will be described with reference to the flow chart shown in FIG.

(A) When the vehicle is stopped In step 100, the rotation speed signals (nf), (nr)
The front wheel rotation speed Nf and the rear wheel rotation speed Nr are proportional to the proportional constant K from the proportional constant setting means 54 according to input signals from the front wheel rotation speed sensor 51 and the rear wheel rotation speed sensor 52 which output
Is read.

In step 101, the vehicle stop is judged (corresponding to vehicle stop detection means) depending on whether the front wheel rotation speed Nf and the rear wheel rotation speed Nr read in step 100 are zero or extremely low.

In step 102, it is judged from the signal from the clutch switch 53 whether or not the clutch pedal is depressed (corresponding to the starting operation detecting means).

In step 103, the command current signal (i) with the command current value i of i = 0 is output.

Therefore, it is detected that the wheel rotation speed is substantially zero and the clutch is not depressed, so that the vehicle is in a stopped state without starting operation. At this time, the clutch hydraulic pressure Pc is zero and the multi-disc friction clutch 19 is engaged. It will be canceled.

(B) At the time of starting operation Whether or not at the time of starting operation is judged by the clutch operation depending on whether or not the clutch pedal is depressed. The flow of control operation is as follows: Step 100 → Step 101 →
The flow proceeds from step 102 to step 104,
In step 104 which is an output step, the command current signal (i) based on the initial command current value i ₀ is output.

Therefore, when the vehicle is started from the stopped state by depressing the clutch pedal, the clutch hydraulic pressure Pc becomes the initial clutch hydraulic pressure Pc ₀ , and the multi-disc friction clutch 19
The initial transmission torque ΔT ₀ is generated by the engagement.

(C) When the vehicle is traveling When the vehicle is traveling, the flow proceeds in the order of step 100 → step 101 → step 105 → step 106 → step 107 → step 108, and the clutch hydraulic pressure Pc is controlled according to the control characteristic map M shown in FIG. Is done.

In step 105, the front and rear wheel rotation speed difference ΔN (= Nr−
Nf) is a calculation step (corresponding to a running state detection means), step 106 is a step of performing a table lookup of the command current value i from the front / rear wheel rotation speed difference ΔN and the control characteristic map M, and step 107 is a proportional constant. This is a step of correcting the command current value i by K, and step 108 is a step of outputting a command current signal (i) based on the final command current value i obtained by the correction calculation.

As described above, in the driving force distribution control device A of the embodiment, the following effects can be obtained.

Since the command current value i is zero and the initial clutch hydraulic pressure Pc ₀ is not applied when the vehicle is stopped without starting operation by the clutch, as shown in FIG. 6, the drain amount ΔV does not occur and the electric motor is turned off. Frequency is increased, and low power consumption and low noise are achieved.

Since at least the initial clutch hydraulic pressure Pc ₀ is applied during traveling after the start operation by the clutch, some driving force is distributed to the front wheels during high-speed straight traveling with almost no difference in front-rear wheel rotation speed ΔN. Therefore, the straight running stability can be improved, and the increase / decrease control of the clutch oil pressure Pc at the time of running by applying the initial clutch oil pressure Pc ₀ can be performed by an immediate oil pressure response, and the control response can be improved. .

Since the initial clutch hydraulic pressure Pc ₀ is applied after the start operation, no delay in response is felt.

When the front-rear wheel rotation speed difference ΔN is less than or equal to a predetermined value ΔN1,
When the command current value i is small and exceeds the predetermined value ΔN1, the command current value i is rapidly increased. Therefore, after preventing the tight corner braking phenomenon in the low rotation speed difference region,
It is possible to achieve effective drive wheel slip suppression in the high rotational speed difference region.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and the present invention can be applied even if there is a design change or the like within a range not departing from the gist of the present invention. included.

For example, in the embodiment, the example of the transfer clutch used as the drive system clutch in the drive force distribution control device for the front and rear wheels is shown. It can also be applied to a center differential clutch that controls the limited amount.

Further, in the embodiment, the example in which the start operation is detected by the clutch operation is shown, but it may be detected by the accelerator pedal operation. In the case of the automatic transmission vehicle, the shift lever is in the N position (neutral). It is also possible to detect that the vehicle is operated from the (position) to the D position (drive position) or the R position (reverse position) and regard it as a start operation.

(Effect of the Invention) As described above, in the drive system clutch control device of the present invention, the clutch hydraulic pressure of the drive system clutch means is set to zero when the vehicle is stopped and the signal indicating the start operation is not output. A clutch control means for applying an initial pressure to the drive system clutch means when the vehicle is stopped and a signal indicating a start operation is output, and for applying a clutch hydraulic pressure to the drive system clutch means in accordance with the running state of the vehicle. Since it has been provided, it is possible to improve straight running stability and control response when shifting from vehicle stop to vehicle running after achieving low power consumption and low noise when the vehicle stops without starting operation. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a conceptual view of a claim showing a drive system clutch control device of the present invention, FIG. 2 is a view showing a drive system control device and a four-wheel drive vehicle of an embodiment, and FIG. 3 is a clutch hydraulic control system of the embodiment device. FIG. 4 is a diagram showing an electromagnetic proportional pressure reducing valve of the embodiment device, FIG. 5 is a control characteristic map diagram of a command current value with respect to a preset rotational speed difference, and FIG. 6 is an embodiment device. Of the relationship between the command current value and the drain amount (clutch hydraulic pressure) of FIG. 7, FIG. 7 is a characteristic diagram of the relationship between clutch hydraulic pressure and transmission torque to the front wheels in the embodiment device, and FIG. 8 is control in the embodiment device. It is a flowchart figure which shows the flow of operation. 1 ... Drive system clutch means 2 ... Clutch hydraulic pressure generation means 201 ... Electric motor 202 ... Hydraulic pump 203 ... Accumulator 204 ... Control valve 3 ... Detection means 301 ... Vehicle state detection means 302 ... Start operation Detection means 4 ... Clutch control means

Claims (1)

[Scope of utility model registration request] 1. A drive system clutch means which is provided in the middle of an engine drive system for transmitting engine drive force to a wheel and is fastened by clutch hydraulic pressure from the outside, and an electric motor and hydraulic pressure which are connected to the drive system clutch means. It has a pump, an accumulator, and a control valve, clutch oil pressure generation means for turning on and off the electric motor by monitoring accumulator oil pressure, vehicle stop detection means for detecting whether the vehicle is stopped, and start operation by the driver. Based on the detection signals from the starting operation detecting means for detecting the presence / absence, the traveling state detecting means for detecting the traveling state of the vehicle, and the detection means from each of the detecting means, when the signal indicating the starting operation is not output when the vehicle is stopped. The clutch hydraulic pressure of the drive system clutch means is set to zero and the drive system clutch is output when the vehicle is stopped and the signal indicating the start operation is output. The initial pressure was applied to the device, it driveline clutch control device according to claim that and a clutch control means for applying a clutch hydraulic pressure to the drive system clutch means in accordance with a running state when the vehicle is running.