JPS63279935A - Controlling method for car clutch - Google Patents

Abstract

PURPOSE:To prevent the abrupt starting of car running, rapid increase in car speed, and the occurrence of instability in the number of engine revolutions by making gradual increase in the transmission torque of a car clutch in starting backward running less than that in starting forward running. CONSTITUTION:In starting forward car running, the transmission torque of a car clutch is gradually increased according to the operating condition of the card, and in starting backward car running, the transmission torque is gradually increased at the rate of increased less than that in starting the forward running. Thus, the torque transmitted from an engine to a speed change gear is more slowly increased in starting the backward running than in starting the forward running.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling transmission torque of a vehicle clutch interposed between a vehicle engine and a transmission.

[Prior Art] Conventionally, a technology has been disclosed for smoothly starting a vehicle by controlling the transmission torque of a vehicle clutch to gradually increase based on the operating conditions of the vehicle, such as the throttle opening and engine speed. (Japanese Patent Application Laid-Open No. 61-206830, JP-A No. 62-31532, JP-A No. 60-1
61221).

[Problems to be Solved by the Invention] However, starting using the conventional technology has the following problems when starting in reverse.

(i) The driver feels uncomfortable because the vehicle starts suddenly.

(ii) It is difficult to operate the accelerator such as when entering a garage.

(iii) Engine knocking may occur or the engine speed may become unstable.

The reason for this problem is that when the vehicle is moving forward and backward, the starting feeling that humans expect is not the same.In other words, when the vehicle is moving forward, the driver expects a quick start, a strong start, etc. On the other hand, when reversing, we expect a slow start and a start that is insensitive to the amount of accelerator depression (the rise of the torque), but conventionally even when starting in reverse, the start is similar to that when moving forward. This is due to the fact that the transmission torque was controlled.As a result, when starting in reverse, the vehicle speed suddenly increases, giving a sudden feeling, or being unable to drive at extremely low speeds, or when the vehicle is in an idling state. It is possible that the clutch transmission torque is large relative to the engine condition for a long period of time, causing the engine speed to become unstable.Also, the total reduction ratio when reversing is usually lower than the reduction ratio when moving forward. Because it is set low, the drive shaft torque (output torque) for the same amount of accelerator depression will be low, and the amount of momentum accelerator depression will increase, resulting in too much output torque, which may make the above problem even more pronounced. be.

An object of the present invention is to solve the above-mentioned problems and thereby improve driving performance and driving feeling when the vehicle is reversing.

[Means for Solving the Problems] As a means for achieving the above object, the method for controlling a vehicle clutch of the present invention, as illustrated in FIG. In a method of controlling a vehicle clutch, the transmission torque of the vehicle clutch at the time of starting is gradually increased at the time of starting based on the driving state of the vehicle. It is characterized in that the amount of increase (step SC) is smaller than the amount of increase (step SS) at the time (step SA).

A vehicle clutch is one whose transmission torque can be controlled by electrical signals from a computer, etc.
An example is a magnetic particle type electromagnetic clutch.

[Operation] In the vehicle clutch control method of the present invention, when the vehicle starts moving forward, the transmission torque of the vehicle clutch is gradually increased based on the driving state (step SA).

SB), when starting backward, the transmitted torque is gradually increased by a smaller increase than when starting forward (step S
A, SC).

Therefore, when the vehicle starts backward, the torque transmitted from the engine to the transmission gradually increases more slowly than when the vehicle starts forward.

In addition, the method of gradually increasing the transmission torque based on the operating state is, for example, calculating the transmission torque TC1 using the following formula (1),
It is known to control the actual value using the torque Tel as a target value.

Tc1=Te+1 (Ne-Nmne)-(1')T
cl...Transmission torque (clutch control value) Te
... 1 for engine torque ... Feedback gain (constant or function of throttle opening) Ne ... Engine rotation speed N111... Target meeting rotation speed (number of people) set according to throttle opening (Target rotation speed when the side rotation speeds are almost the same)) A method to make the gradual increase in transmitted torque when starting backwards smaller than the amount of increase when starting forwards is to change the feedback gain in equation (1) above in the partial throttle range, for example. 1 and the meat rotation speed NII
This may be done by increasing I*, or the above (
1) From the value of the transmission torque TCI calculated by the formula, a predetermined value or throttle opening θ, engine rotation speed Ne,
A function value of 1 (f(θ, Ne, Nm'', 1)) may be subtracted from the target meat rotation speed Nm''#feedback gain.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 2, a vehicle engine 10 is connected to an input shaft 16 of a continuously variable transmission 14 via a powder clutch 12 (details will be described later with reference to FIG. 3), which is a vehicle clutch. The input shaft 16 is provided with a variable pulley 22 whose V-groove width, ie, the diameter of the transmission belt 20, is changed by the hydraulic cylinder 18. The output shaft 24 has a variable pulley 2 whose V groove width is changed by a hydraulic cylinder 26.
8 is provided. Therefore, the rotational force transmitted to the input shaft 16 is transmitted to the output shaft 24 via the transmission belt 20 wrapped around the variable pulleys 22 and 28, and is also transmitted to the attached sub-transmission 30. Sub-shift t13
0 is the first sun gear 32 degrees and the second sun gear 34 degrees. It is equipped with a Ravignaux-type compound planetary gear device consisting of a ring gear 36, etc., and a high-speed clutch 38. Low speed brake 40. By selectively operating the reverse brake 42 by a hydraulic actuator (not shown), the gear ratio Rr of the auxiliary transmission 30 is switched, or forward rotation and reverse rotation are switched, as shown in Table 1 below. It has become.

Table 1 Here, in Table 1, ρ1 is ZS1/Zr-ρ2 is Z
s2/Zr. However, Zsl is the 1st Sangia 3
2, ZS2 is the number of teeth of the second sun gear 34, and zr is the number of teeth of the ring gear 36. The output shaft 24 of the belt-type continuously variable transmission 14 constitutes the input shaft of the sub-transmission ta30, and the carrier 44 that supports the planetary gear in the sub-transmission 30 constitutes the output shaft, so the gear ratio of the sub-transmission 130 is γ (=1/speed ratio e) is a value obtained by dividing the rotation speed of the output shaft 24 by the rotation speed of the carrier 44. The rotational force transmitted to the carrier 44 is transmitted to a pair of drive wheels 52 of the vehicle via intermediate gears 46, 48 and a final reduction gear 50, respectively.

In the vicinity of the variable pulleys 22 and 28, there is an input shaft rotation speed sensor 58 and an output shaft rotation speed sensor 58 for outputting pulse signals SP1 and SF3 of frequencies corresponding to the rotation speeds of the variable pulleys 22 and 28 to the controller 1 to the roller 54. Several sensors 60 are provided. In the vicinity of the intermediate gear 48, a pulse signal Sv having a frequency corresponding to the rotation speed of the intermediate gear 48 is provided.
A vehicle speed sensor 61 is provided for outputting the speed to the controller 554. A throttle valve 62 provided in the intake pipe of the engine 10 is opened and closed by operating an accelerator pedal 63. A throttle sensor 64 is provided on the throttle valve 62, and the throttle valve opening θ is detected from the throttle sensor 64. A throttle signal Sθ representing Sθ is supplied to the controller 54. A cooling water temperature sensor 65a is provided in the water jacket of the engine 10, and a water temperature signal STW representing the cooling water temperature Tw is supplied from the cooling water temperature sensor 65a to the controller 54. The ignition circuit of the engine 10 includes an engine rotation speed sensor 65.
b is provided, and its engine rotation speed sensor 65b
A rotational speed signal SNE representing the engine rotational speed Ne is supplied to the controller 54.

In this embodiment, a shift lever is used as a shift switching device.
66 and a shift mode switch 67 are used, and the operation position sensor 68 that detects the operation position of the shift lever 66 outputs a signal @SP indicating the shift operation position Psh of the shift lever 66. A shift mode signal SW representing shift mode W is supplied to controller 54. This shift lever 66 is mechanically associated with a manual valve in the hydraulic circuit 70, and when operated to the neutral range,
Clutch 3B for high speed, brake 40 for low speed. Hydraulic pressure is prevented from being supplied to any of the hydraulic actuators for operating the reverse brakes 42, but when the reverse range is operated, the reverse brakes 4
Hydraulic oil is supplied only to the hydraulic actuator that operates 2. Further, when the shift lever 66 is operated to the normal driving (D Ni-drive) range of the forward range, hydraulic oil is allowed to be supplied only to the hydraulic actuator that operates the high speed clutch 38, Ensure that the high speed gear is maintained.

Further, when the shift lever 66 is operated to the automatic shift range (S range) or the engine brake range (S range) of the forward range, the high speed clutch 38
It also allows hydraulic oil to be supplied to any of the hydraulic actuators that actuate the low speed brake 40. These hydraulic actuators have a shift type installed in the hydraulic circuit 70! Hydraulic pressure is alternatively supplied from a shift valve that operates in response to the operation of i #-72.

The hydraulic circuit 70 supplies line hydraulic pressure regulated in accordance with the actual gear ratio (speed ratio) of the continuously variable transmission 14 and the output torque of the engine 10 to the hydraulic cylinder 26 provided on the output shaft 24. , to provide necessary and sufficient control of the tension in the transmission belt 20. Further, the hydraulic circuit 70 supplies or discharges hydraulic oil to the hydraulic cylinder 18 provided on the input shaft 16 in response to the operation of the shift direction switching valve 74, and also responds to the operation of the shift speed switching valve 76. In response, the hydraulic oil inflow speed to the hydraulic cylinder 18 or the hydraulic cylinder 1
Change the hydraulic oil discharge speed from 8.

The hydraulic pump 78 is driven by the engine 10 or the like to force-feed the hydraulic oil in the oil tank 80 to the hydraulic circuit 70, and functions as a hydraulic source for the hydraulic circuit 70.

The controller 54 has an input/output interface 82
．． Central processing unit 84. and a storage section 86, etc., and processes various input signals inputted through the input/output interface 82 according to programs and data stored in advance in the storage section 86, and based on the processing results, shifts the solenoid valve for shift. By controlling the operation of 72, the sub-shift 1a
30 gears are automatically shifted, and the shift direction switching valve 74
By controlling the operation of the shift speed switching valve 76, the gear ratio (speed ratio) of the continuously variable transmission 14 is changed to an optimum value, and the amount of excitation of the powder clutch 12 is controlled, thereby maintaining the powder clutch 12. Control the total amount to the optimum value.

The powder clutch 12 fills the gap between the input-side rotating body and the output-side rotating body with magnetic powder by the magnetic force of the excitation coil 88, thereby transmitting torque corresponding to the excitation current flowing through the excitation coil 88 at a constant level. It is designed to transmit according to the transmission characteristics. Figure 3 shows powder clutch 12
An annular yoke 92 serving as an input rotating body is fixed to an input shaft 90 via an outer peripheral member 94. Inside the yoke 92 is an annular excitation coil 8.
8 is embedded, and an excitation current is supplied to the excitation coil 88 via a slip ring 98 fixed to a first labyrinth member 96 that rotates together with a yoke 92. A rotor 100, which is an output rotating body, is mounted on a bearing 10 concentrically with the yoke 92 and rotatable relative to the yoke 92.
is supported by the first labyrinth member 96 via 2,
The rotor 100 is spline-fitted to the shaft end of the output shaft 104. The first labyrinth member 96 has an annular projection 106.
On the other hand, a second labyrinth member 108 having a similar annular protrusion is fixed to the input shaft 90 side of the yoke 92, and the annular protrusion 106 and the second labyrinth member 108 form a substantially airtight area in which magnetic particles are to be enclosed. An annular space is formed. The magnetic particles housed in the annular space move around the rotor 10O according to the magnetic force of the excitation coil 88.
The transmission torque is filled in the gap between the outer circumferential surface of the yoke 92 and the inner circumferential surface of the yoke 92 and is magnetically coupled, and has a magnitude corresponding to the excitation current supplied to the excitation coil 88 to rotate the input shaft 90. The signal is transmitted to the output shaft 104 at . Therefore, the input shaft 90 and the output shaft 104 correspond to the input shaft and output shaft of the powder clutch 12.

The power transmission rate of the powder clutch 12 is proportional to the excitation current (cl) supplied to the excitation coil 88. FIG. 4 is a graph showing the relationship between the excitation current Icl flowing through the excitation coil 88 of the powder clutch 12 and the clutch control value TC1 corresponding to the actual transmission torque of the powder clutch 12.

Next, the clutch and speed change control routine of this embodiment, which is executed at predetermined time intervals, will be explained with reference to the flowchart of FIG. When this routine is called, first shift lever is
66 operating position @ p sh, engine rotation speed Ne, input shaft 16 rotation speed Nin, output shaft 24 rotation speed Noot,
A signal SP is the vehicle speed V based on the throttle opening θ and the rotation speed of the intermediate gear 4B.

SNE, SPl, SP2. It is read based on Sθ and S■ (step 200). Next, shift lever 6
It is determined whether the actual operation position of 6 is in the driving position (neutral, a position other than parking) (step 21).
0)・. If it is determined that the engine is in the running position, it is determined whether the difference between the engine rotational speed Ne and the rotational speed Nin of the input shaft 16 is greater than or equal to a predetermined value δ (here, 50 ppm> (step 220>). Difference between both rotation speeds l Ne-Nin
1 is greater than a predetermined value δ, that is, if the powder clutch 12 is slipping, it is determined whether the throttle valve 62 is open (if the throttle opening θ is rOJ
(step 230). When the throttle valve 62 is open, the storage section 86
The engine torque data map shown in FIG. 6 is selected from a plurality of data maps stored in the data map, and the current engine torque Te corresponding to the engine speed Ne and the throttle opening θ is read from the data map (step 240).
.

Next, it is determined whether the shift lever 66 is in the forward range or reverse range (step 250). This determination is made based on a signal SP representing the shift operation position psh.

If it is determined that it is in the forward range, that is, at the time of forward start, then the target meeting rotation speed Nll shown by the solid line in FIG.
The data corresponding to the current throttle opening θ is read from the data map based on the 1* characteristic and the feedback gain shown by the solid line in FIG. 8 (step 260).
). The target meeting rotation speed Nm read here is small when the throttle opening θ is small, and increases as the opening θ increases, according to the characteristics shown in FIG.

Further, the feedback gain of 1 increases as the throttle opening θ increases, for example, according to the characteristics shown in FIG. This is the only way to optimally control the convergence characteristics.

On the other hand, if it is determined that the shift range is in the reverse range, that is, when starting in reverse (step 250), then the target meeting rotation speed Nll1* shown by the dotted line in FIG. Data corresponding to the current throttle opening θ is read from a data map based on the characteristics and the feedback gain shown by the dotted line in FIG. 8 (step 270). The target rotational speed Nl1l* read here is larger in the partial region for the same throttle opening θ than the rotational speed Nm at the time of forward start referred to in step 260 above.
In medium and high load ranges, the value increases monotonically. Further, the feedback gain of 1 is a smaller value for the same throttle opening of 0 than the gain of 1 at the time of forward start, which was also referred to in step 260 above.

After reading the target rotation speed Nm and the feedback gain of 1 at the time of forward or reverse start, the clutch control value TCI, which is the reference for controlling the transmission torque of the powder clutch 12, is set to It is calculated by performing the calculation of equation (1) described in Section 2 (Step 280).

After the above-mentioned clutch control value Tel is falsified, the excitation f corresponding to the clutch control value Tel! 1 voltage VC+ (: excitation current 1
cl) is output from the controller 54 to the powder clutch 12 (step 290).

Through the above steps 200 to 290, when starting forward or starting backward, the transmission torque of the powder clutch 12 is determined based on the data map for forward starting or the data map for backward starting, and the feedback As a result, as shown in the characteristic diagram of FIG. 9 which shows the value of the clutch control value Tel over time, at the time of forward start, the throttle opening degree θ starts to increase at the time T1. The engine speed Ne quickly reaches the target rotation speed Nm'' (forward) as shown by the solid line, and the clutch control fa T c I increases in a short time as shown by the solid line. On the other hand, when starting in reverse, the engine speed N
As e gradually reaches the target rotational speed Nm'' (reverse) as shown by the dotted line, the clutch control value TC+ gradually increases as shown by the dotted line.

Therefore, when the vehicle starts moving forward, the transmitted torque quickly increases, so there is no sluggish feeling when the vehicle starts moving forward.

On the other hand, when starting in reverse, even if the throttle opening degree θ increases rapidly, the transmitted torque increases slowly. There is no half-clutch running.

As a result, this embodiment has the extremely excellent effect of improving both the running performance and the running feel when starting backward and when starting forward.

After the process of step 290, (a) step 300: control to switch the sub-transmission 30 based on the shift diagram shown in FIG. 10, (b) step 310: target rotation speed shown in FIG. (C) Step 320: Calculate the flow rate valve control value VC based on the following equation (2), and use the value C to determine the shift direction switching valve 74 and shift Control of the speed switching valve 76, VC...2 to the flow rate valve control value...constant Nin...number of revolutions Nin of the input shaft 16...target number of revolutions (d) Step 330: Equation (3) below Based on this, a line pressure control value P1 is determined, and the line pressure is controlled using the value P1.
t1ΔP - (3) Pl...Line pressure control value 1Tel...Absolute value of engine torque e...Speed ratio (=1/gear ratio γ) K3. 4...Constant N0ut...Rotational speed ΔP of the variable pulley 28...Predetermined line pressure is processed, and the gear ratios of the continuously variable transmission 14 and the sub-transmission 30 are controlled.

By executing steps 200 to 330, the vehicle speed V increases, and the vehicle speed V increases at time T2 (forward) or time T2 in FIG.
(Reverse) When the slippage of the powder clutch 12 becomes less than the predetermined value 6, that is, when it is determined in step 220 that l Ne −Ninl < δ, the rotation speed of the input shaft 16 It is determined whether Nin is greater than or equal to a predetermined value α (here, 900 rDOl) (step 340). If the rotational speed Nin of the input shaft 16 is equal to or higher than the predetermined value α, the clutch control value Tel is set to the maximum value (step 350), and the excitation voltage Vcl of the powder clutch 12 is maximized by executing the subsequent step 290.

This completes the engagement of the powder clutch 12.

When the powder clutch 12 is fully engaged, the vehicle speed V decreases and in step 340 Nin<α(θi
), that is, when the rotation speed is lower than the rotation speed α (θi) which is smaller by a predetermined value than the target rotation speed Nin” (stall rotation speed) corresponding to the minimum speed ratio emin (maximum speed ratio γmax×) in FIG. When the rotational speed Nin of the input shaft 16 is reached, the process shifts to step 230 described above.

If it is determined that the throttle is open,
In the subsequent steps 240 to 290, the powder clutch 12 is controlled to be a half-clutch, and if it is determined that the throttle is closed, it is determined that the state is coasting or stopped, and the clutch control value TC+ is set to " 0
” (step 360), and the powder clutch 12
is turned "off" (step 290).

By executing the clutch and speed change control routines described above, the powder clutch 12 is turned off when stopped or coasting at very low speeds, and the powder clutch 12 is controlled to be half-clutched so as to optimally accelerate when starting. During normal driving, the powder clutch 12 is fully engaged. Further, the continuously variable transmission 14 and the sub-transmission 30 are optimally controlled.

Note that the present invention is not limited to the above embodiments,
Various embodiments can be implemented without departing from the gist of the invention.

[Effects of the Invention] The vehicle clutch control method of the present invention makes the gradual increase in the transmission torque of the vehicle clutch when starting backwards smaller than the amount of increase in the transmission torque when starting forwards, so that, for example, when starting forwards, By quickly increasing the transmission torque of the vehicle clutch, the vehicle speed increases quickly when starting forward, and when starting backward, the driving state (e.g. throttle opening) is adjusted.
It is an extremely powerful vehicle that improves both driving performance and driving feel by gently increasing the transmitted torque even when the vehicle speed suddenly changes, thereby preventing sudden starts, rapid increases in vehicle speed, unstable engine speed, etc. It has excellent effects.

[Brief explanation of drawings]

FIG. 1 is a flowchart illustrating the basic configuration of a control method for a vehicle clutch according to the present invention, FIG. 2 is an overall configuration diagram of a vehicle to which an embodiment of the present invention is applied, and FIG. A configuration diagram of the clutch, FIG. 4 is a graph showing the control characteristics of the powder clutch of the embodiment, FIG. 5 is a flowchart of the clutch and shift control routine of the embodiment, and FIG. 6 is a graph showing the engine torque characteristics of the embodiment. FIG. 7 is a graph showing the target rotation speed characteristics of the embodiment, FIG. 8 is a graph showing one characteristic for the feedback gain of the embodiment, and FIG.
10 is a graph showing the shift pattern of the auxiliary transmission of the example, and FIG. 11 is a graph showing the target rotation speed characteristic of the example. 10... Engine 12... Powder clutch 14... Continuously variable transmission 54... Controller 61... Vehicle speed sensor 64... Throttle sensor 68... Operation position sensor

Claims (1)

[Scope of Claims] A method for controlling a vehicle clutch in which the transmission torque of a vehicle clutch interposed between the engine and transmission of the vehicle at the time of startup is gradually increased at the time of startup based on the driving state of the vehicle, A method for controlling a clutch for a vehicle, characterized in that the transmission torque is gradually increased when the vehicle is started in reverse by a smaller amount of increase than when the vehicle is started in the forward direction.