JPS63318361A - Lock-up controller for automatic transmission equipped with auxiliary transmission - Google Patents

Abstract

PURPOSE:To execute the always optimum lock-up control according to the speed change stage by installing a means for changing the lock-up control by a lock-up control means according to the speed change stage of a subtransmission, in the operation region where the lock-up device is set into slip state. CONSTITUTION:When the speed change stage of a substransmission B is switched to the low speed stage when the engine revolution speed increases as a whole, the slip region of a lock-up device A is changed to the region spread towards the low car speed stage than that in the high speed stage by a lock-up control varying means F. The control for maintaining the lock-up device A in the slip state up to the min. engine revolution speed where the engine stahl is not generated in any speed change stage is performed, and the fuel combustion efficieney can be improved to the limit, surely avoiding the increase of the vibration noise, engine stahl, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic transmission for a vehicle, and more particularly to a lockup control device for an automatic transmission equipped with a torque converter lockup device and an auxiliary transmission.

(Prior Art) In recent years, automatic transmissions installed in vehicles are equipped with a lock-up device that directly connects the input and output members of a torque converter, and has been equipped with a lock-up device that directly connects the input and output members of the torque converter, and has been equipped with a lock-up device that does not require the torque increase function or shift shock absorption function of the torque converter. A device has been put into practical use that reduces the deterioration in fuel efficiency caused by so-called slippage of the torque converter by tightening this lock-up device in the operating range of the torque converter.

On the other hand, as with manual transmissions, there is also a demand for automatic transmissions to have multiple gears so that optimal power performance can always be obtained depending on the driving condition. An automatic transmission equipped with this has been realized.

An automatic transmission equipped with both a lockup device and an auxiliary transmission as described above has been disclosed, for example, in Japanese Patent Application Laid-Open No. 61-16776.
As disclosed in Publication No. 8, in the automatic transmission disclosed in this publication, lockup characteristics that are always suited to the gear position can be obtained by changing the engagement area of the lockup device depending on the gear position of the auxiliary transmission. It is designed as follows.

(Problem to be Solved by the Invention) Incidentally, in order to improve fuel efficiency, it is desirable to engage the lock-up device in as wide a range as possible, but the lock-up device does not engage in the low engine speed range where torque fluctuations are significant. If this is done, the torque fluctuations will be directly transmitted to the transmission, increasing vehicle vibration and noise.

In other words, regarding the control of the lock-up device, there are two conflicting demands: improvement of fuel efficiency and suppression of vibration and noise, and the key issue is how to achieve both of these demands.

Therefore, in an automatic transmission equipped with a lockup device and an auxiliary transmission, the present invention sets a slip region in which the input and output sides of the lockup device slip at a predetermined rotational speed difference, and makes this slip region effective. By utilizing this control, it is possible to suppress vibration and noise while improving fuel efficiency as much as possible.In particular, this slip area itself or the amount of slip of the lock-up device in this area can be controlled by changing the speed of the sub-transmission. It is an object of the present invention to always perform optimum lockup control according to the gear position by changing the gear position according to the gear position.

(Means for Solving the Problems) In order to achieve the above object, the present invention is characterized by the following configuration.

That is, as shown in FIG. 1, an automatic transmission C is provided with a torque converter lockup device A and an auxiliary transmission B.
The lock-up device A is set to at least either a released state or a slip state depending on the operating region, and in the slip region, a lock-up control means for controlling the amount of slip of the lock-up device A, and a lock-up control means for controlling the slip amount of the sub-transmission B are provided. It is provided with a gear position detecting means E for detecting the gear position, and a lockup control changing means F for changing the lockup control by the lockup control means according to the gear position of the auxiliary transmission B detected by the detecting means E. As for the change of lock-up control by this change means F,
Depending on the gear position of the auxiliary transmission B, there are cases in which the slip area of the lockup device A is changed, cases in which the target slip amount of the lockup device fiA in the slip area are changed, and cases in which both are changed at the same time.

(Function) According to the above configuration, for example, when the gear position of the sub-transmission B is switched to a low gear position where the engine speed is generally high, the changing means F changes the slip area of the lock-up device A to a high speed. If the shift is changed to a region that extends to the lower vehicle speed side than when the gear is in gear, control will be performed to maintain the lock-up device A in the slip state to the lowest engine speed that does not cause stalling, regardless of the gear. This makes it possible to improve fuel efficiency to the limit while reliably avoiding increases in vibration noise and engine stalling.

Also, for example, when the gear position of the sub-transmission B is switched to a low gear position where engine rotational fluctuations are amplified and transmitted,
By changing the slip amount of the lock-up device A in the slip region to be larger than that at high speed, it is possible to avoid deterioration of fuel efficiency due to an unnecessarily large slip amount at high speed, while reducing vibration at low speed. , the transmission of noise will be effectively suppressed.

(Example) Examples of the present invention will be described below.

As shown in FIG. 2, the automatic transmission 1 according to this embodiment is for a 41611 motor vehicle, and includes a torque converter lO connected to the output shaft 3 of the engine 2, and a torque converter lO connected to the output shaft 3 of the engine 2. A main transmission 20 arranged, a sub-transmission 30 arranged on the output side of the main transmission 20, a four-wheel drive state in which the output of the sub-transmission 30 is transmitted to the front wheels and rear wheels, and only the rear wheels. and a 2-4 switching section 40 that performs switching between the two-wheel drive state and the two-wheel drive state.

As shown in FIG. 3, the sub-transmission 30 is a main transmission 2.
A planetary gear mechanism 33 is arranged between the input shaft 31 from the 0 side and the output shaft 32 to the 2-4 switching section 40 side, and the ring gear 34 of the mechanism 33 is connected to the input shaft 31, and the binion carrier 35 is connected to the input shaft 31. A high-speed clutch 37 is interposed between the sun gear 36 and the input shaft 31 to connect and disconnect the sun gear 36 and the input shaft 31, and a low-speed brake 38 is provided to fix the sun gear 36. There is.

When the high speed clutch 37 is engaged and the low speed brake 38 is released, the ring gear 3 of the planetary gear mechanism 33
4 and the sun gear 36 are connected via the high-speed clutch 37, and the entire mechanism 33 rotates integrally, thereby obtaining a high-speed gear in which the rotation of the input shaft 31 is directly transmitted to the output shaft 32, Furthermore, when the high speed clutch 37 is released and the low speed brake 38 is engaged, the sun gear 36 is fixed, so that the rotation of the input shaft 31 input to the ring gear 34 is decelerated, and the pinion carrier 35
is transmitted to the output shaft 32 to obtain a low speed gear.

Further, the 2-4 switching section 40 directly connects the output shaft 32 of the sub-transmission 30 to the propeller shaft 41 for the rear wheels, and also connects the first gear 42 loosely fitted onto the output shaft 32 and the front wheel An integral second gear 45 is connected to the front wheel output shaft 44 connected to the front propeller shaft 43 via an idle gear 46, and these are connected between the auxiliary transmission output shaft 32 and the first gear 42. The structure includes a 2-4 switching clutch 47 that connects and disconnects. When the 2-4 switching clutch 47 is engaged, the rotation of the sub-transmission output shaft 32 is also transmitted to the front propeller shaft 43, resulting in a four-wheel drive state in which both the front and rear wheels are driven. Furthermore, when the clutch 47 is released, a two-wheel drive state in which rotation is transmitted only to the rear propeller shaft 41 can be obtained. A hydraulic control circuit for controlling engagement and release of the high speed clutch 37, low speed brake 38, and 2-4 switching clutch 47 is provided.

As shown in FIG. 4, this control circuit connects a line pressure passage 50 led from a control valve (not shown) for controlling the main transmission 20 to the high speed clutch 37, low speed brake 38, and The first switch selectively communicates with the four-way switching clutch 47. The second and third switching valves 51, 52, 53, and the first valve that controls the operation of these valves 51-53, respectively.
゜Second. These control valves 55 to 56 are connected to the gear changeover switch 6.
It is turned on and off by a control unit 60 to which signals from the 1 and 2-4 changeover switches 62 are input.

Here, the control unit 60 includes sensors 63 and 64 that detect vehicle speed and engine throttle opening, respectively.
, and signals from sensors 65 and 66 (see FIG. 2) that detect the rotational speed on the output side of the torque converter 10, respectively, are inputted to the valve 7 for lock-up control, which will be described later.
It is designed to control the operation of 2.

Then, a signal from the control unit 60 causes the first
．． When the second control valves 54 and 55 are both turned OFF, the first control valve 54 and 55 are both turned off. Control pressure is introduced into the control boats 51a and 52a of the second switching valves 51 and 52, respectively, and the spool 5
1b and 52b move to the left in the drawing, the line pressure passage 50 is communicated with the oil passage 37a leading to the high speed clutch 37 via the first switching valve 51, and the clutch 37 is engaged. , the hydraulic pressure in the low speed brake 38 is transmitted through the oil passage 38a, the second switching valve 52 and the oil passage 38.
The water is drained from the first switching valve 51 via b, and the low gear brake 38 is released, thereby setting the auxiliary transmission 30 to the high gear. In addition, when the first control valve 54 is turned on and the second control valve 55 is turned off by a signal from the control valve) 60, the first control valve 54 is turned on and the second control valve 55 is turned off.
By draining the control pressure from the control boat 51a of the switching valve 51 and moving the spool 51b to the right in the drawing, the hydraulic pressure in the high speed clutch 37 is drained via the oil passage 37a and the first switching valve 51. The clutch 3
7 is released, control pressure is introduced into the control boat 52a in the second switching valve 52, and the spool 52
b is located on the left side in the drawing, the line pressure passage 50 is communicated with the oil passage 38a leading to the low speed brake 38 via the first switching valve 51, the oil passage 38b and the second switching valve 52, The brake 38 is engaged, thereby causing the sub-shift I! 30 is set as the low gear.

Furthermore, when the third control valve 56 is turned on, the third control valve 56
By draining the control pressure in the control boat 53a of the switching valve 53 and moving the spool 53b to the right in the drawing, the line pressure passage 50 is connected to the third switching valve 53.
When the clutch 47 is engaged and the third control valve 56 is turned off, the control port 53a of the third switching valve 53 is connected to the oil passage 47a leading to the 2-4 switching clutch 47 through When pressure is introduced and the spool 53b moves to the left in the drawing, the above 2-
The hydraulic pressure in the four-wheel drive clutch 47 is drained through the oil passage 47a and the third switch valve 53, and the clutch 47 is released, thus switching between the four-wheel drive state and the two-wheel drive state is performed. It is becoming more and more popular.

On the other hand, as shown in FIG. 5, the torque converter 10 includes a pump 12 that is fixed to one side of a case 11 connected to the engine output shaft 3 and rotates integrally with the engine output shaft 3. A turbine 13 is disposed on the other side of the case 11 to face the pump 12 and is rotationally driven by the pump 12 via fluid; a stator 14 that increases torque when the speed ratio of the turbine 13 to the turbine 12 is below a certain level; The rotation of the turbine 13 is input to the main transmission 20 via the turbine shaft 16.

The lock-up clutch 15 is connected to the torque converter 1
The clutch 15 is engaged by the pressure of the hydraulic oil introduced into the case 11 of the clutch 1, and is released when hydraulic pressure is introduced into the release chamber 17 provided between the clutch 15 and the engine side side of the case 11. It has become so. The control valves of the main shift 1fi 20 include a lock-up valve 71 that controls the introduction of release pressure from the line pressure passage 50 to the release chamber 17, and a control valve 72 that is a duty solenoid that controls the operation of the valve 71. are provided. This control valve 72 is turned on and off in short cycles by signals from the control unit 60.
When activated, the control pressure in the control boat 71a of the lock-up valve 71 is drained when the lock-up valve 71 is turned ON, and the control pressure in the control boat 71a is introduced into the boat 71a when the lock-up valve 71 is OFF. ratio of ON time during
It is designed to be adjusted accordingly. By moving the spool 71b of the lock-up valve 71 in accordance with this control pressure, the release chamber 17 in the torque converter 10 is connected from the line pressure passage 50 to the release passage 73.
The lockup release pressure introduced into the lockup is regulated. Here, as the duty ratio of the control valve 72 becomes larger, the control pressure decreases, and the lock-up release pressure also decreases accordingly, and as shown in FIG. Below the value D1, the release pressure P becomes the maximum value, and the lock-up clutch 15 becomes completely released (transmission torque T=0%), and above the relatively large second predetermined value D2, the release pressure P becomes 0. Therefore, the lock-up clutch 15 is set to be in a fully engaged state (transmission torque T=100%).

When the duty ratio is between the first predetermined value D1 and the second predetermined value D2, the lock-up clutch 15 is in a slip state and torque is transmitted at a rate corresponding to the duty ratio.

The torque converter 10 is provided with an oil passage 74 that supplies hydraulic oil into the case 11 and an oil passage 76 that guides the hydraulic oil from inside the case 11 to the cooler 75.
A pressure retaining valve 77 is installed in the latter oil passage 76, and the case 1
The oil pressure inside the pump is maintained at a predetermined value.

Next, lock-up control, which is a feature of the present invention, will be explained according to the specific operation of the control unit 60.

This control is performed according to the flowcharts in FIGS. 7 and 9 and the control map in FIG.
Based on the signals from the vehicle speed sensor 63, throttle opening sensor 64, and gear changeover switch 61 shown in FIG.
The gear position is read and a determination is made as to whether the gear position is a high gear position "H" or a low gear position "L". If the gear is set to high speed "°H'°", step 84
- S8, or when the low speed gear is set to "L", the lock-up clutch 15 is controlled in accordance with the operating range, respectively, in accordance with steps 89-S13. In other words,
As shown in FIG. 8, the lock-up clutch 15 is engaged in the engagement areas IH, IL and the slip area 11o for each gear stage of the sub-transmission 30, using the vehicle speed and the throttle opening as parameters.
, n- are respectively set as control maps, and when the high speed gear is "H", it is determined in step S4 whether or not the actual driving range (vehicle speed and throttle opening) belongs to the slip region H□ for the high speed gear. When the low speed gear is "L", it is determined in step S9 whether or not it belongs to the slip area IIL for low speed gears.
1111L is provided on the low vehicle speed side, and each area ILIL for the low gear is connected to each area IH and IIN for the high gear.
It is said to be an area that has expanded or shifted to the lower vehicle speed side.

In either case, the slip areas Ill, Il
If it does not belong to t, step S5. After the duty rate of the lock-up control valve 72 is once set to the first predetermined value D1 in the SIO, step s6. In Sll, it is determined whether or not the actual driving range belongs to the engagement range IHIIL, and if it does, step S7. Set the above duty rate to 100% in S12, and if it does not belong, step S8
+ S I3 sets the duty rate to 0%.

Thereafter, the control unit 60 controls the lock-up control pulp 7 at the duty rate set as described above.
2 (step 514), thereby fastening region I
When it does not belong to H, IL (and slip region III, It) (duty rate D = 0%), the release pressure P of the lock-up clutch 15 is set to the maximum value and the clutch 15 is released as shown in FIG. When the clutch is completely released and is in the engagement region IN, I (duty rate D=100%), the release pressure P is set to 0 and the lock-up clutch 15
will be fully concluded. In that case, if the engine speed is set to the low gear "L" where the engine speed is generally higher, the lock-out movement and noise will be reduced to the minimum allowable vehicle speed down to a lower vehicle speed than if the engine speed is set to the high gear "HII". The lock-up clutch 15 is engaged until the engine rotational speed reaches , thereby ensuring that vibration and noise problems are avoided and fuel efficiency is improved as much as possible.

On the other hand, when the high speed gear is set to "H", the operating region belongs to the high speed slip region (■), and when the low speed gear is set to "L", the operating region belongs to the low speed slip region When it belongs to the region IIL, the control unit 60 executes the slip control from step S4 or S9 to step S15. This slip control is performed as follows according to the flowchart shown in FIG.

That is, first, the gear position of the auxiliary transmission 30 is determined in steps 321 to S23, and if the gear position is high, the control target value N of the slip amount N of the lock-up clutch 15 is determined. is set to a first predetermined value nH (for example, 60 RPM) for the high speed stage,
In the case of the low speed gear "°L°', the target value No. is set to the first predetermined value n, and the second predetermined value nL for the lower gear (for example, 10100RP). Then, in step S24+
325, calculate the actual slip amount N, and calculate the deviation Δ of this slip jlN from the above target value N.
Calculate N (=N No). Here, as shown in FIG.
It is obtained by determining the difference between the engine rotation speed NE and the turbine rotation speed NT detected by the turbine rotation speed sensor 66 and the turbine rotation speed NT.

Next, the control unit 60 performs steps 326 to S2.
9, the above deviation ΔN is “+′°, °O゛ or °゛-
When “°+′”, that is, the actual slip amount N
When exceeds the target value No, a predetermined value d is added to the current duty rate, when it is O'', the duty rate is maintained as it is, and when -'', that is, the actual slip j
When LN is less than the target value N, a predetermined value d is subtracted from the current duty rate. Then, using the duty ratio thus set, the lock-up control valve 72 is driven in step S14 in FIG. As a result, when the slip amount N is larger than the target value NO, the release pressure P of the lock-up clutch 15 is reduced due to an increase in the duty ratio, and the clutch 15 is controlled in the engagement direction, and the slip amount N is When it is smaller than the target value No, the above-mentioned release pressure P increases due to a decrease in the duty ratio, and the clutch 15 is controlled in the releasing direction, and in this way, the slip IN of the clutch 15 reaches the target value N.
(It will be converged to 1 (no or nL).

The region in which such slip amount control is performed is the region 11t in the low gear "L" where the engine speed is high throughout the shell, and the region 11t in the high gear "H" where the vehicle speed is lower than the region 11t in the high gear "H". Since the lock-up clutch is set to the side, the slip state is maintained up to the limit speed that does not cause the engine to stall in any gear, and the lock-up clutch is unnecessarily released at relatively high engine speeds. In addition, the amount of slip of the lock-up clutch 15 in these slip regions II) 1. Since the slip amount nL at "H" is set larger than the slip amount nH at high speed "H", it is possible to avoid deterioration of fuel efficiency due to setting this slip amount to an unnecessarily large value. Even in this gear position, vibrations and noise caused by the transmission of the rotational fluctuations are effectively suppressed.

In this embodiment, both the slip area of the lock-up clutch 15 and the amount of slip in the slip area are changed depending on the gear position of the sub-transmission 3. It may also be possible to only make changes.

(Effects of the Invention) According to the present invention, in an automatic transmission equipped with a lockup device for a torque converter and an auxiliary transmission, the lockup device can be set to at least a released state and a slip state depending on the operating range. In addition to changing the slip area of the lock-up device according to the gear position of the auxiliary transmission, and also changing the slip amount of the lock-up device in the slip area according to the gear position of the auxiliary transmission. Since at least one of the above is performed, the slip control of the lock-up device can be performed appropriately at any gear stage, without causing deterioration in fuel efficiency due to unnecessary release of the device. It is possible to effectively prevent vibrations, noise increase, engine stalling, etc. caused by engine rotational fluctuations.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the overall configuration of the present invention, Figures 2 to 9
The figures show an embodiment of the present invention; FIG. 2 is a schematic overall configuration diagram of an automatic transmission; FIG. 3 is a schematic diagram showing the configuration of an auxiliary transmission and a 2-4 switching section in the automatic transmission; Fig. 4 is a control circuit diagram of the sub-transmission and 2-4 switching section, Fig. 5 is a diagram showing the configuration of the torque converter and the control circuit of the lock-up device, Fig. 6 is a control characteristic diagram of the lock-up device, and Fig. 7 is a diagram showing the control circuit of the lock-up device. 8 is a flowchart showing the overall control operation of the lockup device, FIG. 8 is a diagram showing its control area, and FIG. 9 is a flowchart showing slip control of the lockup device. 1... automatic transmission, 10... torque converter, 1
5...Lockup device (lockup clutch),
30... Sub-transmission, 60, 71.72... Lock-up control means, lock-up control change means (control unit, lock-up valve, lock-up control valve), 61... Gear stage detection means (gear stage switching) switch).

Claims (1)

[Claims] (1) A lock-up control device for an automatic transmission equipped with a torque converter lock-up device and an auxiliary transmission, the lock-up device being at least in a released state or a slip state according to a preset operating range. and a lock-up control means for controlling the slip amount of the lock-up device in the slip region, a gear position detection means for detecting the gear position of the sub-transmission, and a sub-transmission detected by the detection means. Lockup control changing means for changing at least one of the slip area of the lockup device in accordance with the gear position of the transmission and the target slip amount of the lockup device in the slip area also in accordance with the gear position; A lock-up control device for an automatic transmission with an auxiliary transmission, comprising: