JPH05223165A - Start controller for fluid coupling - Google Patents

Abstract

PURPOSE:To prevent excessive fluctuation of real engine rotation number and reduction of starting torque by calculating target engine rotation number according to throttle openings in starting and calculating joint oil pressure of a fluid coupling to eliminate deviation from real engine rotation number. CONSTITUTION:A continuously variable transmission is provided with a belt-type continuously variable transmission unit in which engine power is inputted through a fluid coupling 2 and is controlled by an oil pressure circuit. The oil pressure circuit is provided with the first and the second electromagnetic valves 26, 27 in which line pressure regulated in a regulator valve 21 is supplied, a manual valve 28 in which pressure oil decompressed in a modulator valve 23 is supplied, a clutch control valve 29, and so on. The clutch control valve 29 is controlled by ECU 36 so as to switch on or off the joint oil pressure path 32 and the stop oil pressure path 33 of the fluid coupling 2, however, in controlling, joint oil pressure of the fluid coupling is calculated to remove deviation between the target engine rotation number found according to the throttle openings and real engine rotation number so as to control the clutch control valve 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a start control device for a fluid coupling provided in a power transmission system provided with a fluid coupling for intermittently transmitting the rotational force of an engine to a continuously variable transmission, and more particularly to fluid coupling control means. Relates to a start control device for a fluid coupling that performs a connecting / disconnecting operation of the fluid coupling in accordance with engine operating information.

[0002]

2. Description of the Related Art Conventionally, as a power transmission system connected to an engine of a vehicle, a fluid coupling, a forward / reverse switching portion, a continuously variable transmission portion, a final reduction gear, a differential and wheels are known.

As a fluid coupling here, a damper clutch includes a compressor integrally joined to an engine and a turbine connected to and separated from the compressor and connected to a transmission side, and pressure oil supplied from a clutch control valve through a joint hydraulic passage. Are joined together, and the pressure oil from the hydraulic disconnection path is received to divide the hydraulic oil. Conventionally, this damper clutch is switched according to the pilot pressure from the electromagnetic control valve, and the electromagnetic control valve is driven according to the control output of the clutch control means. In this case, the clutch control means is engaged / disengaged in accordance with the engine operation information, especially the gear stage information.

On the other hand, the continuously variable transmission supplies the gear ratio control oil pressure based on the gear ratio determined according to the operating information of the engine to the gear ratio control valve, and the two pulley control oil pressures regulated by the valve are used as primary and The secondary hydraulic actuators are supplied to the secondary hydraulic actuators, whereby the winding diameter ratio of the belts wound around the pair of pulleys is changed to perform continuous gear shifting. Here, when the same hydraulic pressure is supplied to both hydraulic actuators, the winding diameter ratio of the primary pulley is set to be larger than that of the secondary pulley, so that a low gear ratio (high gear stage) is achieved, and conversely, on the primary cylinder 1 side. A high gear ratio (low gear stage) is achieved in accordance with the decrease in the hydraulic pressure of.

Further, the forward / reverse switching section attached to the continuously variable transmission is supplied with respective switching control pressure oil from a manual valve for shifting the speed, to a hydraulic actuator for forward / backward switching of the switching section. The actuator is configured to switch between forward and backward stages.

In such a power transmission system, a target engine speed Neo is usually set in accordance with the throttle opening, as shown in the M3 map in FIG. 5, and the same engine speed Ne is set.
The continuously variable transmission operates at o, and the high gear ratio (low gear) L
From the side toward the low speed ratio (high speed stage) OD, continuously variable speed is continuously performed to increase the vehicle speed V.

[0007]

However, when the clutch control means sets the target engine speed Neo by the throttle opening when the vehicle is started by such a device, the engine speed becomes the target engine speed Neo.
The damper clutch is engaged after reaching the target engine speed. Until the target engine speed Neo is reached, the damper clutch is disengaged and the engine speed is controlled to increase quickly.

Therefore, at the time of starting the vehicle, the slip state of the damper clutch changes according to the degree of engine output, the degree of slip between the compressor on the engine side and the turbine side receiving the load on the wheel side, and the like. Therefore, when the engine speed increases at the time of starting and approaches the target engine speed Neo, the time-dependent change characteristics of the engine speed differ from time to time. In particular, when the slip amount is large, only the increase in the engine output speed rapidly progresses, and exceeds the target value as shown by the broken line e1 in FIG. 4, or conversely, when the slip amount is small, the chain double-dashed line e2 in FIG. As shown in, the engine speed may drop rapidly. When the engine speed exceeds the target value, the engine output is largely used only for increasing the rotation speed, and the starting torque becomes small. On the contrary, when the engine speed greatly decreases, the engine goes to an engine stall due to insufficient output. In some cases, the starting characteristics became unstable depending on the degree of slippage of the damper clutch, which was a problem.

An object of the present invention is to provide a starting control device for a fluid coupling, which can improve the starting characteristics.

[0010]

In order to achieve the above object, the present invention relates to a compressor which rotates integrally with an engine and a compressor which is connected to the compressor by receiving pressure oil from a joint hydraulic passage. Of a fluid coupling provided with a turbine that receives and separates pressure oil from the hydraulic coupling, a continuously variable transmission that is disposed in a power transmission system including the fluid coupling and that can continuously achieve a target gear ratio, and joining of the fluid coupling A fluid coupling including a clutch control valve that supplies switching pressure oil to the hydraulic path and the hydraulic disconnection path in response to a switching command, and a fluid coupling control means that controls switching of the clutch control valve side in accordance with engine operating information. In the start control device, the fluid coupling control means calculates a target engine speed according to the throttle opening of the engine, and a deviation between the target engine speed and the actual engine speed. Calculating a joint hydraulic elimination possible the fluid coupling, and controlling the clutch control valve to supply the same bonding pressure to the joint hydraulic path.

[0011]

The fluid joint control means calculates the target engine speed according to the throttle opening of the engine, calculates the joint hydraulic pressure of the fluid joint that can eliminate the deviation between the target engine speed and the actual engine speed, and Since the clutch control valve is driven to supply the joining hydraulic pressure to the joining hydraulic passage, the target engine speed can be set according to the desired characteristic and the same characteristic can be achieved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The starting control system for a fluid coupling shown in FIG. 1 is installed in a power transmission system of a vehicle. As shown in FIG. 2, this power transmission system includes an engine 1, a fluid coupling 2, a continuously variable transmission 3, a reduction gear 4, a differential 5, left and right axle shafts 6 and drive wheels (not shown), and rotational force is transmitted in this order. It is configured to The fluid coupling 2 includes a compressor 8 that rotates integrally with the engine output shaft 7, a turbine 9 that receives the rotational energy of the compressor 8 via oil, and a direct coupling clutch 10 described below. The tip of the compressor 8 is pivotally supported concentrically with the turbine shaft 11 on the base of the casing 14 via a bearing 12. Here, the tip of the compressor 8 also serves as the drive shaft of the oil pump 13, and thereby oil can be supplied to the continuously variable transmission 3 and the fluid coupling 2.

The continuously variable transmission 3 comprises a forward / reverse switching unit 15 and a continuously variable transmission unit 16. Forward / reverse switching section 15
Is a turbine shaft 11 pivotally supported between a pair of bearings 12 and 17.
A forward clutch 18 and a reverse clutch 19 are provided in front of and behind. The forward clutch 18 includes a peripheral portion of a front rotor 20 that is integral with the turbine shaft 11 and a carrier 22 of a planetary gear train 21 described later.
The hydraulic piston 23 for the forward clutch is used to switch between the peripheral portions of and. Here the planetary gear train 2
1 is a sun gear 24 that is integral with the turbine shaft 11, a plurality of planetary gears 25 that are meshed around the sun gear 24 and are pivotally supported by a carrier 22,
Ring gear 26 having inner peripheral teeth with which planetary gear 25 meshes
Composed of and. The reverse clutch 19 has a braking function to bring the outer peripheral portion of the ring gear 26 into contact with and separate from the casing 14, and is switched by a hydraulic piston 27 for the reverse clutch 19. In this case, when only the forward clutch 18 is engaged, the turbine shaft 11 and the carrier 22 side are integrated, and the engine rotation is maintained as it is in the main shaft 2 of the continuously variable transmission portion 16.
8 and the reverse clutch 19 alone is engaged, the rotation of the turbine shaft 11 is reversed and transmitted to the main shaft 28 of the continuously variable transmission unit 16 on the carrier 22 side.

The continuously variable transmission portion 16 is provided with a main shaft 28 which is integral with the carrier 22 and a sub shaft 2 which is arranged parallel to the main shaft 28 at a predetermined distance.
9, the main shaft has a main pulley 30 and the sub shaft 29 has a sub pulley 3
1 is provided, and an endless belt 32 is stretched between both pulleys. The pulleys 30 and 31 are both divided into two parts, and the movable-side pulley members 301 and 311 are fitted onto the fixed-side pulley members 302 and 312 so that they can rotate relative to each other and can be separated from each other with a relative interval. This movable pulley material 30
Reference numerals 1 and 311 denote primary cylinders 3 as hydraulic actuators for operating a relative distance from a fixed pulley material.
3 and the secondary cylinder 34 are mounted. In this case, the movable-side pulley member 301 is brought closer to the fixed-side pulley member 302 of the main pulley 30 to increase the winding diameter of the main pulley, and the movable-side pulley 311 is kept away from the fixed-side pulley member 312 of the sub-pulley 31 and the winding diameter is increased. To reduce the winding diameter ratio (sub-pulley winding diameter / main pulley winding diameter), that is, to set a low gear ratio (high gear stage), and operate in reverse to increase the high gear ratio (low gear stage). Configured to achieve.

The reduction gear 4 has a structure in which a final gear 37 is connected to a gear 35 integral with the auxiliary shaft 29 via a gear train 36, and the differential 5 accommodates an operating mechanism in a differential casing (not shown) integral with the final gear 37. However, a well-known configuration is adopted in which the rotational force is divided into two and output after allowing the left-right rotation difference. The hydraulic circuit of the fluid coupling 2 and the forward / reverse switching unit 15 of FIG. 2 will be described with reference to FIG. This hydraulic circuit is provided with an oil pump 13, the discharge oil of which is the fluid coupling 2 and the forward clutch 18 of the forward / reverse switching unit 15.
It is also supplied to the reverse clutch 19 and the continuously variable transmission section 16 side.

Here, the oil pump 13 is driven in accordance with the rotation of the engine to change its hydraulic pressure. Therefore, the maximum allowable pressure of the discharge pressure is regulated by the line pressure regulator valve 20, and the line pressure which is a set value is set. The regulator valve 21 operates to adjust the pressure so as to hold the pressure. A part of the line pressure passage 22 is pressure-reduced and adjusted to a set value by the clutch pressure modulator valve 23, and the clutch pressure modulator valve 23 passes through the clutch oil passage 24 to the manual valve 28 and further the pressure adjusting oil passage 25.
And is supplied to the first solenoid valve 26 and the second solenoid valve 27.

The regulator valve 21 is a line pressure passage 22.
And a clutch port 223 for supplying pilot pressure from the second solenoid valve 27, a clutch oil supply port 223 for supplying oil to the clutch control valve 29, and a drain port 224. The pilot pressure and the two springs 3 are provided.
The hydraulic pressure of the line pressure passage is adjusted according to the balance operation with 0 and 31.

The manual valve 28 is interlocked with a manual switching lever (not shown) for shifting gears, and the forward side D,
The oil passages are switched according to each range of 2, L, the reverse range R range, and each range of neutral N and parking P. That is, this manual valve 28 is
4, an oil supply port 241, which communicates with the forward clutch 18, a forward port 242 which communicates with the forward clutch 18, and a reverse port 243 which communicates with the reverse clutch 19. Here, in each range of the forward drive side D, 2 and L, the forward drive clutch 18 is joined to the oil supply port 241 and the engine rotation is transmitted to the continuously variable transmission section 16 as it is. It is transmitted to the gear shift unit 16.

The fluid coupling 2 allows relative rotation between the compressor 8 and the turbine 9 when the direct coupling clutch 10 is disengaged to transmit rotation based on the flow resistance, and when the direct coupling clutch 10 is engaged, the compressor 8 on the engine output shaft 7 side is sometimes transmitted. And the turbine 9 on the turbine shaft 11 side are integrally transferred. The direct coupling clutch 10 receives pressure oil from the joining hydraulic passage 32 to join, and receives pressure oil from the disconnecting hydraulic passage 33 to divide the oil. These two oil passages are connected to the clutch control valve 29. The clutch control valve 29 includes a line pressure port 291 connected to the line pressure passage 22, an oil supply port 292 communicating with the clutch oil supply port 223 of the regulator valve 21, a pilot port 293 for receiving the pilot pressure of the first solenoid valve 26, and a closed circuit 3.
4, a pair of closed ports 294 and 295 connected to each other, a joining port 296 for communicating the joining hydraulic passage 32, and a hydraulic disconnection passage 3
3 is provided with a disconnection port 297 that communicates with 3. The spool 29 of the valve 29 performs a balance operation based on the hydraulic pressure of the pressure adjusting oil passage 25, the elastic force of the spring 36, and the pilot pressure applied thereto.

As a result, the spool 35 is switched and adjusted to the disconnection position S1 shown by the solid line, the joining position S2 shown by the chain double-dashed line, and an intermediate position therebetween. At the disengagement position S1, the oil supply port 292 communicates with the disconnection port 297 and the hydraulic disconnection passage 33, the direct coupling clutch 10 is disconnected, and at the joining position S2, the line pressure port 291 penetrates between the lands a and b. ,
The closed port 294, the closed path 34, the closed port 295, the joint port 296, and the joint hydraulic passage 32 communicate with each other, and the direct coupling clutch 10
Join together. Particularly, in this case, the first solenoid valve 26 adjusts the hydraulic pressure of the pressure adjusting oil passage 25 to the pilot pressure according to the commanded duty ratio Du, and supplies the pilot pressure to the pilot port 293. It is configured so that the force can be adjusted.

In the fluid coupling 2, the forward / reverse switching unit 15 and the continuously variable transmission unit 16 as described above, each electromagnetic control valve in their hydraulic circuits is connected to the CVTECU 36 as a control means and controlled. The CVT ECU 36 also has a function as a fluid coupling control means, a main part of which is constituted by a microcomputer, and a built-in memory circuit has control programs of the CVT control processing routine of FIG. 8 and the clutch control processing routine of FIG. Is being stored.

Here, the CVTECU 36 receives an engine speed N from an engine control unit (not shown).
e, throttle opening θs, vehicle speed V, etc. are input.
The rotation information of the main and sub pulleys 30 and 31 is fetched by a sensor (not shown), and based on the information, the continuously variable transmission control of the continuously variable transmission is performed according to a well-known program.

The start control processing of the fluid coupling will be described below with reference to the control programs of FIGS. 8 and 9 and the block diagram of FIG. In the present embodiment, the engine body 1 is started by operating an ignition key (not shown), and an engine control unit (not shown) performs fuel supply control, ignition control, etc. according to engine operating information, and the CVTECU 36 performs fluid control along with this. The joint 2, the forward / reverse switching unit 15 and the continuously variable transmission unit 16 are controlled.

First, the CVTECU 36 fetches throttle opening θs, engine speed Ne, vehicle speed V, main and auxiliary pulley speeds Wp and Ws of the continuously variable transmission, and other data from an engine control unit and sensors (not shown).
When the current vehicle speed V is smaller than the vehicle stop determination speed Va, the process proceeds to step 3, and when the vehicle has started, the process proceeds to step a4. Step a3
As shown in FIG. 9, the start processing of the first step is θs, Ne, V
The latest necessary data such as is taken in and the required torque is calculated from the current θs, Ne based on the torque calculation map M1 shown in FIG. This torque calculation map can calculate the currently generated torque T at each throttle opening θs and engine speed Ne. Subsequently, the joining force capable of transmitting the torque T is calculated based on the reference joining hydraulic pressure P _B calculation map M2, which is the reference joining hydraulic pressure P _B that can be generated by the direct coupling clutch 10.

At step b4, the target engine speed Neo is obtained from the target engine speed calculation map M3 of FIG. 5 from the throttle opening θs. Here, the target engine speed calculation map in FIG. 5 is a map of the target engine speed Neo capable of optimizing the power performance at each throttle opening θs, which is indicated by the broken lines in FIG. It is created from a value corresponding to the maximum torque value of the opening degree θs. At steps b5 and b6, the difference ΔN between the target engine speed Neo and the actual engine speed Ne is determined, and the difference ΔN is calculated.
The proportional term ΔP _P is calculated by multiplying N by the proportional coefficient. Here, it is obtained from the proportional term calculation map M4. Step b
In 7 and b8, the difference ΔN is sequentially integrated to calculate the integral value ΣΔN _I , and the same value is multiplied by the integral coefficient ρ _KI to calculate the integral term ΔP _I. In this case, the integral value ΣΔN _I is multiplied by a limiter process of the maximum value ΔP _IH and the minimum value ΔP _IL to prevent the divergence of control, and the integral term ΔP _I is set.

In steps b9, b10 and b11, the proportional integral term ΔP _PI is calculated from the proportional term ΔP _P and the integral term ΔP _I. This value is calculated in order to bring the engine rotational speed Ne close to the target engine rotational speed Neo so as to generate a joining force in the direct coupling clutch 10 to reduce or increase the engine rotational speed. Therefore, subsequently, the proportional integral term ΔP _PI is subtracted from the reference joint hydraulic pressure P _B to calculate the target joint hydraulic pressure P, and the duty ratio Du corresponding to the joint hydraulic pressure P is calculated from the duty ratio calculation map M5. , The same value is output.

As a result, as shown by the solid line in FIG. 4, in the starting range S, the engine speed (engine output shaft 7 side)
At time t1, Ne starts the process of increasing the engine speed toward the target engine speed Neo corresponding to the throttle opening θs at that time. The actual engine speed Ne is the target engine speed Ne.
If the actual engine speed temporarily tries to suddenly increase while reaching o, the rotational load based on the proportional integral term ΔP _PI is applied to the engine output shaft 7 side by the joining force of the direct coupling clutch 10, and the actual engine speed Ne becomes It is possible to prevent excessive swinging, to prevent the engine output from being used only for increasing the engine speed to cause a decrease in the starting torque, and to make the actual speed approach the target engine speed Neo relatively early. .. In the starting area S, the fluid coupling 2 has a flow resistance between the compressor 8 and the turbine 9 and the direct coupling clutch 1
Rotation is transmitted by the frictional force associated with the joining force of 0. The output rotation, that is, the rotation speed No of the turbine shaft 11 is the time t.
It gradually increases from 1 toward time t2, and after time t2,
That is, after the start range S has passed and the target engine speed Neo has been reached, the rotation speed on the engine output shaft 7 side substantially matches when the direct coupling clutch 10 is completely engaged.

After such a start processing routine, step a4 of the main routine is reached. The CVT control process here is a well-known program, that is, the target gear ratio is calculated to maintain the target engine speed Neo corresponding to the throttle opening θs, and the main and sub pulleys 30 and 3 are used to achieve the same gear ratio.
The winding ratio of 1 is adjusted by adjusting the hydraulic pressures of the primary cylinder 33 and the secondary cylinder 34, and then the control process returns to step a1.

[0029]

As described above, according to the present invention, the target engine speed according to the throttle opening of the engine can be calculated during the starting process, and the deviation between the target engine speed and the actual engine speed can be eliminated. The joint hydraulic pressure of the fluid coupling can be calculated, and the fluid coupling can be driven with the same joint hydraulic pressure to adjust the actual engine speed to the target engine rotational speed. It can be prevented from being used only for increasing the number and causing a decrease in the starting torque.

[Brief description of drawings]

FIG. 1 is a schematic overall configuration diagram of a start control device for a fluid coupling as one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a power transmission system of a vehicle including the start control device for the fluid coupling of FIG.

FIG. 3 is an operation explanatory view of a clutch control valve in the start control device for the fluid coupling of FIG.

FIG. 4 is a time-dependent operation explanatory diagram in the start control device of the fluid coupling of FIG. 1.

5 is a functional block diagram of the start control device for the fluid coupling in FIG. 1. FIG.

6 is an engine speed-torque characteristic diagram of a fluid coupling used in the start control device for the fluid coupling of FIG.

7 is a control characteristic diagram of the continuously variable transmission in the power transmission system equipped with the start control device for the fluid coupling of FIG. 1. FIG.

8 is a flowchart of a control program executed by the start control device for the fluid coupling in FIG.

9 is a flowchart of a control program executed by the start control device for the fluid coupling shown in FIG.

[Explanation of symbols]

 1 engine 2 fluid coupling 3 continuously variable transmission 7 engine output shaft 8 compressor 9 turbine 10 direct coupling clutch 11 turbine shaft 16 continuously variable transmission section 29 clutch control valve 36 CVTECU Ne engine speed θs throttle opening

Claims (1)

[Claims] 1. A fluid coupling provided with a compressor that rotates integrally with an engine, and a turbine that receives pressure oil from a joint hydraulic path to connect to the compressor and connects the compressor to receive pressure oil from a hydraulic disconnection path to divide the same. , A continuously variable transmission that is arranged in a power transmission system including the fluid coupling and that can continuously achieve a target gear ratio, and a switching pressure in accordance with a switching command between a joint hydraulic path of the fluid coupling and the hydraulic disconnection path. In a start control device for a fluid coupling, comprising: a clutch control valve that supplies oil; and a fluid coupling control means that controls switching of the clutch control valve side according to engine operating information, wherein the fluid coupling control means is a throttle of the engine. The target engine speed according to the opening is calculated, and the joint hydraulic pressure of the fluid joint that can eliminate the deviation between the target engine speed and the actual engine speed is calculated. Start control apparatus for a fluid coupling, characterized in that for controlling the clutch control valve to supply to the junction a hydraulic path.