JPS62205826A - Drive system clutch control device for vehicle provided with shift pattern change-over type transmission gear - Google Patents

Abstract

PURPOSE:To enhance the control stability and running stability of a vehicle, by setting at least two control characteristics having different widths of increases and decreases in the fastening force of a clutch with respect to variations of input signals, by selecting at least one of them in accordance with the characteristic of speed change of a transmission gear. CONSTITUTION:A drive power dividing device 3 for dividing and transmitting the drive force of an engine to left and right drive wheels 1, 2, has a drive system clutch means 4 for changing the transmission torque in accordance with the degree of fastening force of a clutch. A clutch control means 6 controls the clutch means 4 in accordance with a signal from a detecting means 5 for detecting the running or operating condition of a vehicle. In this arrangement, at least two control characteristics having different widths of increases and decreases in clutch fastening force with respect to variations and decreases in clutch fastening force with respect to variations of the input signals are set in the control means 6. Further, one of the control characteristics which is suited with the speed change characteristic of a shift pattern change-over type transmission gear 7 is selected to control the clutch means 4.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is used in a power split device such as a differential device or a transfer device of a four-wheel drive vehicle, and is used to control the amount of differential differential between left and right wheels and drive the front and rear wheels. The present invention relates to a drive system clutch control device for a vehicle equipped with a shift pattern switching type transmission that variably controls a force distribution ratio.

(Prior Art) Conventionally, as a device for controlling the clutch engagement force of a differential limiting clutch, which is an example of a drive system clutch, a device as described in Japanese Utility Model Application Publication No. 58-177642 has been known. ing.

This conventional arrangement is provided with a centrifugal clutch that fixes at least either the pinion gear or the side gear to the differential case when the differential case rotates at high speed.

Note that this centrifugal clutch is a differential limiting clutch in which the clutch engagement force increases as the rotational speed of the differential case increases.

In addition, conventionally, differential locking devices (
As a device for controlling the differential limiting means, for example, a device as described in Japanese Patent Application Laid-Open No. 60-143135 is known.

This conventional device operates a differential locking device to limit the differential movement between the left and right wheels when the accelerator pedal is operated in a manner that may cause the wheels to spin.

(Problem to be solved by the invention) However, in the former conventional example, the differential limiting amount was controlled only depending on the rotation speed of the differential case, that is, the vehicle speed, and therefore When driving at high speeds, a high differential limit can be obtained to ensure driving stability, but by switching the transmission's shifting characteristics to a power pattern (torque-oriented pattern), sudden acceleration or rapid acceleration can be achieved at low or medium speeds. There has been a problem in that the amount of differential restriction is insufficient during sports driving such as starting.

In addition, in the latter conventional example, the differential limiting amount was controlled solely by operations that could cause wheelspin, that is, acceleration operations using the accelerator pedal, so sudden acceleration and During sports driving where a sudden start is performed intentionally, it is preferable to respond sensitively to the accelerator pedal operation and increase the differential limit amount, but during normal driving with the transmission's shifting characteristics switched to the standard pattern, the differential limit amount increases. There have been problems in that the limit amount changes too sensitively, resulting in sudden changes in steering force and changes in vehicle behavior that are too large.

(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 conceptual diagram of the claim shown in FIG. Input from a drive system clutch means 4, which is provided between the part and the drive output part, and whose transmission torque can be changed depending on the magnitude of the clutch engagement force, and a detection means 5, which detects the traveling state or driving state of the vehicle. Clutch control means 6 that controls increase/decrease in clutch engagement force based on the signal;
In the drive system clutch control device for a vehicle equipped with a shift pattern switching type transmission, the clutch control means 6 includes:
A control characteristic is set that includes at least a first control characteristic in which the clutch engagement force increases or decreases in a small range in response to a change in the input signal, and a second control characteristic in which the clutch engagement force increases or decreases in a large range in response to a change in the input signal, and From the control characteristics of
' control characteristics can be selected.

In addition, shift pattern switching type transmissions include automatic transmissions that can change the shift schedule to switch between sport and standard patterns, manual transmissions that have an auxiliary transmission and can switch between power mode and economy mode, etc. say.

(Function) Therefore, in the drive system clutch control device for a vehicle equipped with a shift pattern switching type transmission of the present invention, by using the above-mentioned means, for example, a shift pattern switching type transmission can be provided with normal shifting characteristics. When driving in the shift pattern mode, the first control characteristic in which the clutch engagement force increases or decreases in response to input signal changes is selected, resulting in clutch engagement force control that is less affected by acceleration operations, etc., and improves steering stability and driving. Stability can be maintained. In addition, when driving with a shift pattern switching type transmission switched to a shift pattern mode that provides torque-oriented shifting characteristics, the second control characteristic, which has a large increase/decrease range in clutch engagement force in response to changes in the input signal, is selected and accelerates. It is sensitive to operations and can run while minimizing wheel slip.

(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 control device for an automobile equipped with an automatic transmission with shift pattern switching and a multi-disc friction clutch means (differential limiting clutch means) operated by external hydraulic pressure will be described. Take for example.

First, the configuration of the 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 hydraulic pressure generator 12, and a control unit (clutch control unit). means) 13, detection means 14,
It is equipped with a shift pattern select switch 15, 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.
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 are 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 rear axle run plate 29.29'.
, thrust bearing 30.30', spacer 31.31'
, bushing rod 32, hydraulic piston 33, oil chamber 34,
A hydraulic port 35 is provided.

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.
It is reported that the rear axle lamp plate is 29.29'.

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 its fitting portion has a rectangular cross section as shown in FIG. The shaft end portion 19a is fitted into the shaft end portion 19a through square grooves 28a, 28'a, and the structure is such that no thrust force is generated due to a difference in rotation, unlike the conventional torque proportional differential limiting means.

The hydraulic piston 33 moves in the axial direction (rightward in the drawing) by supplying hydraulic pressure to the hydraulic port 35, and engages both the multi-disc friction clutches 27, 27' according to the hydraulic pressure level. In the clutch 27, the tightening force is transmitted from the bushing rod 32 to the spacer 31 to the thrust bearing 30 to the rear shaft damping plate 29, and the pressure ring 2
8 as a reaction force receiver, and the other multi-disc friction clutch 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.
, pump motor 41, pump pressure oil line 42. Drain oil passage 43, control pressure oil passage 44, electromagnetic proportional pressure reducing valve 46 having a valve solenoid 45, return oil passage 47, oil temperature sensor 4
8, a switching solenoid valve 50 having a valve solenoid 49, an orifice 51, and a reserve tank 52 are provided.

The electromagnetic proportional pressure reducing valve 46 converts the hydraulic oil at the pump pressure supplied from the hydraulic pump 40 via the pump pressure oil line 42 into the control current signal (i) from the control unit 13.
Therefore, the control oil pressure P is proportional to the control current value of 1 quintillion.
(Fig. 5) is a valve actuator that sends the control oil pressure P from the control pressure oil passage 44 to the oil pressure port 35 and the oil chamber 34, and the control current signal (i) is the valve solenoid of the electromagnetic proportional pressure reducing valve 46. 45.

The control oil pressure (clutch pressure) P and the differential limiting torque T have the following relationship: TocP-4・n-r-A n; number of clutches r: clutch average radius A; pressure receiving area, and the torque shown in Fig. 6 As shown in the characteristics, the differential limiting torque T is proportional to the control oil pressure P.

The switching solenoid valve 50 is an oil passage opening/closing means provided in the middle of the return oil passage 47 from the return port 53 opened to the oil chamber 34, and is set by the oil temperature signal (1) from the oil temperature sensor 48. When a signal indicating a low oil temperature below the oil temperature To is input, a solenoid activation signal (d) is output from the control unit ) 13, the return oil passage 47 is opened, and the hydraulic oil is circulated.

Therefore, by circulating the hydraulic oil when the oil temperature is low, even if the viscosity of the hydraulic oil becomes high at low oil temperatures, the hydraulic oil circulation can prevent a decrease in hydraulic response. By providing the orifice 51 in the return oil path, the oil pressure can be increased while circulating the hydraulic oil.

The control unit 13 uses the microcomputer of the car t, and includes an input circuit 131, a RAM (random, access, memory) 132, a ROM (read,
only, memory) 133, CPU (central, processing, unit/) 134, clock circuit 135.
An output circuit 136 is provided.

In addition, as an input means to the control unit 13,
A vehicle speed sensor (vehicle speed detection means) 141 and an accelerator opening sensor (acceleration operation detection means) 142 are provided as detection means, and a shift pattern select switch 15 is provided as shift pattern selection means.

The input circuit 131 is a circuit that receives input signals (V), (a) from the input means 14 and a switch signal (S) from the shift pattern select switch 15.

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

The ROM 133 is a read-only memory,
Information necessary for arithmetic processing by the CPU 134 is stored in advance and read out from 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 136 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 vehicle speed sensor 141 is a sensor that detects the vehicle speed V of the vehicle and outputs a vehicle speed signal (V) according to the vehicle speed V.

The accelerator opening sensor 142 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).

Incidentally, the vehicle speed sensor 141 and the accelerator opening sensor 142 are connected to the first sensor preset in the control unit 13.
It is used as a sensor for searching the target clutch pressure P from the control characteristic map M1 (FIG. 7) or the second control characteristic map M2 (FIG. 8).

The shift pattern selection switch 15 is a shift pattern selection means provided in a position that can be manually operated from the driver's seat in the vehicle interior, and as shown in FIG. It is equipped with Auto mode 5, which automatically selects the mode, and Power mode, which is used during sports driving.

Furthermore, from this shift pattern select switch 15,
A switch signal (S) corresponding to the selected mode position is output to the input circuit 131 of the control unit 13.

Further, as shown in FIG. 7, the ROM 133 of the control unit 13 stores the accelerator opening A from 0% to 10%.
Even if it changes to 0%, the accelerator opening gain remains constant (K
= 1), that is, the first control characteristic map M1 that is highly dependent on the vehicle speed V is set, and the eighth
As shown in the figure, the accelerator opening A is 0%, 25%, and 50%.
When changing from % to 100%, the accelerator opening gain will be
Kz, 3, Ka depending on accelerator opening A
, Ks, that is, a second control characteristic map M2 that is highly dependent on the accelerator opening degree A is set.

However, the recontrol characteristic maps Ml and M2 both have a vehicle speed of 71
In order to improve straight-line stability in the high vehicle speed range (vehicle speed 80 km/h) or higher, the accelerator opening gain in the low vehicle speed range is increased.
The accelerator opening gain in the high vehicle speed range is increased by 2, and the clutch pressure P increases as the vehicle speed increases even with a small accelerator opening, creating a progressive characteristic.

In addition, the shift pattern select switch 15 is made of Au.
The criteria for selecting knobs Ml and M2 in both of the above control characteristics when the to mode is selected is whether the accelerator opening change rate which is the time change rate of the accelerator opening A is 8 or less. (Person≦A''), or exceeds the limit (bundle to A>).When A≦A*, the first control characteristic map M1 is selected, and when AHA'', the second control characteristic map is selected. M2 is selected.

In other words, the first control characteristic map M1 is selected when the shift pattern select switch 15 selects the 5 standard mode or the Auto mode and when A≦AK, and the second control characteristic map M2 is selected. The selection is made with the shift pattern select switch 15.
This is done when the er mode or the Auto mode is selected and A) A''.

Next, the operation of the embodiment will be explained.

First, the operational flow of the differential limiting control according to the embodiment will be described with reference to the flowchart shown in FIG.

(a) When the 5 standard mode is selected, during normal driving, press the shift pattern select switch 15 to 5 tan.
If the dard mode is selected, step 200-
The operation flow is step 201 → step 202 → step 203 → step 204 → step 205, and in step 205, which is the output step, the control current signal (i) based on one control current value that obtains the searched target clutch pressure Pa is output. Output.

In step 200, the vehicle speed ■ is determined by the vehicle speed signal (V) from the vehicle speed sensor 141, the accelerator opening degree A is determined by the accelerator opening signal (&) from the accelerator opening sensor 142,
This is a step of reading the switch signal (5) from the select switch 15.

Step 201 is a calculation step for calculating the accelerator opening change rate A based on the current accelerator opening An read in step 200 and the previously read accelerator opening An-+.

The calculation formula for the accelerator opening change rate A is t: control cycle time.

Step 202 is a mode determination step in which the selected mode is determined based on the switch signal (S) read in step 200.

Step 203 is a characteristic selection step in which a control characteristic M^ corresponding to the accelerator opening degree A is selected from the first control characteristic map Ml, and step 204 is a characteristic selection step in which a control characteristic M^ corresponding to the accelerator opening degree A is selected from the first control characteristic map Ml, and a target clutch is selected based on the control characteristic M^ selected in step 203 and the vehicle speed V. This is a search step for searching for pressure PO.

In this way, the shift pattern select switch 15
When the standard mode is selected, the accelerator opening gain K is constant (K-Kt), and the clutch pressure is controlled based on the first control characteristic map M1, which is highly dependent on the vehicle speed V, and the clutch pressure due to acceleration operation is There is no sudden change in P, the higher the vehicle speed V, and the greater the accelerator opening A.

A large amount of differential restriction is obtained, resulting in control suitable for normal driving.

(b) When selecting Auto mode When the select switch 15 is selected to Auto mode, step 200 → step 201 → step 2
The operation flow is 02 → step 206 → step 203 (or step 207) → step 204 → step 205, and in step 205, which is the output step, the control current value 1 is set to obtain the searched target clutch pressure PO.
A control current signal (i) according to the present invention is output.

In step 206, the accelerator opening change rate A calculated in step 201 is compared with the set accelerator opening change rate A, and if A≦A end, the first control characteristic map M! , and if A>A'', then the second control characteristic map is selected.

In this way, with the shift pattern select switch 15,
When the auto mode is selected, depending on the magnitude of the accelerator opening change rate A, which is the time change rate of the accelerator opening A, the first control characteristic map M1, which is highly dependent on the vehicle speed V, or the accelerator opening A The second type, which is highly dependent on (acceleration operation)
One of the control characteristic maps M2 is automatically selected,
Control characteristics suitable for the driving condition are automatically selected without performing a switching operation using the shift pattern select switch 15.

(c) When power mode is selected When driving in a sporty manner with sudden depressing or sudden release of the accelerator pedal, and when shift pattern select switch 15 is selected to po%ler mode, step 200 → step 201 The operation flow is as follows: → Step 202 → Step 207 → Step 204 → Step 205. In step 205, which is the output step, a control current signal (i) based on the control current value i which obtains the searched target clutch pressure Pa is output. Ru.

Incidentally, step 207 is a characteristic selection step in which a control characteristic M^ corresponding to the accelerator opening degree A is selected from the second control characteristic map M2.

In this way, the shift pattern select switch 15
When the upper mode is selected, the accelerator opening gain K is large, that is, the clutch pressure is controlled based on the second control characteristic map M2 that is highly dependent on the accelerator opening A, and responds sensitively to acceleration operations. Clutch pressure P increases, resulting in control suitable for sports driving.

As explained above, in the automobile differential limiting clutch control device of the embodiment, the control unit 13
, a first control characteristic map M1 in which the accelerator opening gain K is highly dependent on the vehicle speed V and constant, and a second control characteristic map M2 in which the accelerator opening gain K increases with acceleration operation are set, and these control characteristics map M2 are set. Since either of the characteristic maps Ml and M2 is configured to be selected by the shift pattern select switch 15, during normal driving with the 5 standard mode selected, the first control characteristic map Mt is selected to reduce the influence of acceleration operations. Clutch engagement force is controlled and steering stability and running stability can be maintained.
In addition, when driving in sports with the power mode selected, the responsiveness to acceleration operations is sensitive, driving while suppressing wheel slip, etc., and the differential limit amount is controlled using a control characteristic mode suitable for the driving condition. I can do it.

In addition, in the embodiment, shift pattern select switch 1
5 modes include Auto mode, and this Auto
When selecting the mode, the driver automatically selects between the first control characteristic map M1 and the second control characteristic map M2 depending on the driver's accelerator opening change rate. Control characteristics suitable for the driving condition are selected without any operation.

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, an example of a differential limiting clutch control device is shown, but it can also be applied to a transfer clutch that changes the driving force distribution ratio of a transfer device that distributes the driving force between the front and rear wheels of a four-wheel drive vehicle. In this case, the same effect as in the case of a limited differential clutch can be obtained.

In addition, although an example of an automatic transmission with shift pattern switching was shown in the embodiment, a vehicle has a manual transmission that has an auxiliary transmission and can switch multiple transmission characteristics such as power mode and economy mode by switching the auxiliary transmission. It can also be applied to

In this case, switching the shift pattern is not limited to manual switching, but may also be automatic switching depending on the driving conditions, and can be easily performed by inputting a switching signal to the control unit.

Further, although a hydraulically operated clutch is shown in the embodiment, other clutch means such as an electromagnetic clutch may be used.

Further, in the embodiment, an electromagnetic proportional pressure reducing pulp 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, the drive system clutch control device for a vehicle with a shift pattern switching type transmission of the present invention has the following features:
The clutch control means is set with a control characteristic that includes at least a first control characteristic in which the clutch engagement force increases or decreases in a small range in response to a change in the input signal, and a second control characteristic in which the clutch engagement force increases or decreases in a large range in response to a change in the input signal. And, from these control characteristics, one mode that is compatible with the shift characteristics of the shift pattern switching type transmission is selected. ・The drive system clutch is controlled using control characteristics that match the shift characteristics of the transmission. You can get the effect of being able to do things.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of a claim showing a drive system clutch control device for a vehicle with a shift pattern switching type transmission according to the present invention, and Fig. 2 shows a differential device incorporating a differential limiting means of an embodiment of the present invention. 3 is a view in the Z direction of FIG. 2, FIG. 4 is a diagram showing the hydraulic pressure generator and control device of the embodiment device, and FIG. 5 is the characteristic of the control hydraulic pressure (clutch pressure) with respect to the control current value. Fig. 6 is a differential limit torque characteristic diagram with respect to control oil pressure P, Fig. 7 is a first control characteristic map which is stored in advance in the control unit, and Fig. 8 is a second control characteristic map which is stored in advance in the control unit. The control characteristic map diagram and FIG. 9 are flowcharts showing the flow of the differential limiting control operation of the embodiment device. 1.2... Drive wheel 3... Power split device 4... Drive system clutch means 5... Detection means 6... Clutch control means

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, A drive system clutch means capable of changing the transmission torque depending on the size, and a clutch control means that controls increase/decrease of the clutch engagement force based on an input signal from a detection means for detecting the traveling state or driving state of the vehicle. In the drive system clutch control device for a vehicle with a shift pattern switching type transmission, the clutch control means has a first control characteristic in which the clutch engagement force increases or decreases in a small range in response to input signal changes, and a first control characteristic in which the clutch engagement force increases or decreases in response to input signal changes. A second control characteristic having a large increase/decrease range is set, and
A drive system clutch control device for a vehicle with a shift pattern switching type transmission, characterized in that one control characteristic matching the shift characteristics of the shift pattern switching type transmission is selected from these control characteristics.