JPH03244869A - Automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To perform such a running as nearer to the ordinary running even if a failure occurs in a friction engaging means by engaging the abnormal friction engaging means normally or releasing it normally so as to make it become a shift speed train suitable to the required running conditions. CONSTITUTION:An automatic transmission consists of first - third planetary gear mechanisms 1-3, and it is set to multiple shift speeds when clutch means K1-K4 and brake means B2, B3 are selectively engaged or released. Here, when trouble happens in either of these friction engaging means K1-K4 and B2, B3 and the troubled state makes these friction engaging means possible into a normally engaging state or a normally releasing state, a control unit E selects an advantageous shift speed train on the basis of the required running conditions, and the troubled friction engaging means are normally engaged or released. Thus, such a running as nearer to the ordinary running is performable even if a failure occurs in the friction engaging means.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to an automatic transmission for a vehicle that sets a plurality of gears by engaging and disengaging frictional engagement means.

BACKGROUND TECHNOLOGY As is well known, conventional automatic transmissions consist of a gear train made up of multiple gear mechanisms with differential operation, such as planetary gear mechanisms, and the connected and fixed states of the elements of these gear mechanisms. Alternatively, the connection relationship with the input shaft may be changed using frictional engagement means such as a clutch or brake to set a plurality of gears. In addition to being as small and lightweight as possible, automatic transmissions of this type are designed to improve starting performance, quietness at high speeds, and improved fuel efficiency. It is desired that there are many possible gears. An example of an automatic transmission that meets such requirements is the one described in Japanese Patent Application Laid-Open No. 60-57036. To briefly explain its configuration, it is mainly composed of three sets of single pinion type planetary gear mechanisms, and the sun gear of the first planetary gear mechanism and the sun gear of the second planetary gear mechanism are always or selectively operated. The sun gear of the first planetary gear mechanism and the carrier of the second planetary gear mechanism are connected via a clutch as necessary, and the ring gear of the second planetary gear mechanism and the ring gear of the third planetary gear mechanism The carriers of the first planetary gear mechanism are connected to these ring gears, and the carrier of the second planetary gear mechanism and the sun gear of the third planetary gear mechanism are connected via a clutch. The input shaft is connected to the first
It is connected to the sun gear of the planetary gear mechanism and the sun gear of the second planetary gear mechanism via clutches, and is connected to the ring gear of the first planetary gear mechanism via another clutch. On the other hand, the output shaft is connected to the carrier of the third planetary gear mechanism. The braking means for stopping the rotation includes a brake that fixes the sun gear of the first planetary gear mechanism and a sun gear of the second planetary gear mechanism that are connected to each other, and a brake that fixes the sun gear of the third planetary gear mechanism. ing.

The automatic transmission disclosed in JP-A No. 60-57036 has five forward speeds and one reverse speed, as well as 2' and 3rd speeds between the 2nd and 3rd forward speeds. It is possible to set the 3'th gear between the 4th gear and the forward gear for a total of 7 gears, and the gear ratio of the 1st gear is sufficiently large for good starting performance. Moreover, it is possible to set an overdrive stage, and it seems to be quiet at high speeds and have good fuel efficiency.

Problems to be Solved by the Invention In the conventional automatic transmission described above, seven forward gears and one reverse gear can be set using five clutch means and two brake means. If excessive slip occurs in the multi-disc clutch, multi-disc brake, or band brake due to wear of the friction material or failure of the hydraulic mechanism, or if an abnormality occurs such as not completely releasing the brake, the It is no longer possible to set a gear position using the engaging means, that is, a gear position to be engaged or a gear position to be disengaged. The basic idea of how to deal with such an abnormality is to configure each mechanism to operate safely, which is known as a fail-safe. The preferred control when the above-mentioned abnormality occurs in the engagement means becomes more diverse as the number of gears that can be set and the number of engagement means for setting each gear increase. It is not immediately clear how to apply the fail-safe concept to achieve specific control, and this point is not described in the above-mentioned publication, and has not received particular attention in the past.

This invention was made against the background of the above-mentioned circumstances, and an object of the present invention is to provide an automatic transmission capable of driving closer to normal driving even if a failure occurs in the frictional engagement means. .

Means for Solving the Problems In order to achieve the above object, the present invention provides an automatic transmission system having a gear train that is set to a plurality of gear stages according to a combination of engagement and disengagement of a plurality of frictional engagement means. In a transmission, when an abnormality is detected in a frictional engagement means that can be always engaged or always disengaged, a gear stage sequence that can be set by always engaging the frictional engagement means with the abnormality and always The frictional engagement means with the abnormality is constantly engaged so that an advantageous gear range is selected based on the required driving conditions from among the gear ranges that can be released and set, and the selected gear range is set. Alternatively, the device is characterized by having a control device that allows the device to be released at all times.

Operation In the automatic transmission of the present invention, a plurality of gear stages can be set by appropriately switching the engagement/release states of the plurality of frictional engagement means. If an abnormality occurs in any of these frictional engagement means and the abnormal state is such that the frictional engagement means can be constantly engaged or released, the control device will perform the following: to control. In other words, since the frictional engagement means with the abnormality should be engaged at some gear and released at some other gear, if it is always engaged,
Any of the other gears cannot be set, and the gears will be shifted according to the gear train consisting of the remaining other gears,
The same applies even if it is released all the time. Therefore, the control device determines which is more advantageous for the driving conditions: the gear range obtained when the abnormal friction engagement means is always engaged, or the gear range obtained when it is always disengaged. to judge. Here, the driving condition is, for example, the driving range selected by the shift lever, and if it is the drive (D) range, there are many gears that can be set, and if it is the drive (D) range, the number of gears that can be set is large;
If it is a range, you can set a low gear, and reverse (R
) range, it is an advantageous gear sequence to be able to set a reverse gear. In addition, engine cooling water temperature, overdrive switch on/off, etc. can be used as driving conditions, or a combination of these can be used.

Then, the control device constantly engages or disengages the frictional engagement means in the abnormal state so as to provide an advantageous gear shift sequence. As a result, the vehicle can travel more closely to normal travel.

Example Next, embodiments of the invention will be described with reference to the drawings.

In the example shown in Fig. 1, the gear train is constructed mainly of three sets of single pinion type planetary gear mechanisms 1, 2.3, and each element in each of these planetary gear mechanisms 1, 2.3 is as follows. It is connected and structured as follows. That is, the first
The carrier IC of the planetary gear mechanism 1 and the ring gear 3R of the third planetary gear mechanism 3 are connected to rotate together, and the ring gear 2R of the second planetary gear mechanism 2 and the carrier 3C of the third planetary gear mechanism 3 are connected so that they rotate together. Further, the sun gear IS of the first planetary gear mechanism 1 is connected to the carrier 2C of the second planetary gear mechanism 2 via the second clutch means 2, and the second planetary gear mechanism 2 is connected to the fourth clutch means via 4. sun gear 2S
and further connected to the carrier 2C of the second planetary gear mechanism 2.
is connected to the sun gear 3S of the third planetary gear mechanism 3.

Note that as a connection structure for each of the above-mentioned elements, a connection structure used in general automatic transmissions such as a hollow shaft, a solid shaft, or an appropriate connecting drum can be used.

The human power shaft 4 is connected to an engine (not shown) via a power transmission means (not shown) such as a torque converter or a fluid coupling, and the input shaft 4 and the ring gear IR of the first planetary gear mechanism 1 In between, there is a first
A clutch means Kl is provided, and a third clutch means 3 is provided between the input shaft 4 and the sun gear IS of the first planetary gear mechanism 1 to selectively connect the two.

In addition, in practical use, each of the above-mentioned clutch means Kl,
4 can be configured as a multi-disc clutch, a one-way clutch, or a combination thereof, and since there are restrictions on the arrangement of each component, a connecting drum is used as a connecting member for each clutch means Kl and 4. Of course, an appropriate intermediate member such as the like may be interposed.

Further, the carrier 2C of the second planetary gear mechanism 2 and the transmission case (hereinafter referred to as
A second brake means B2 is disposed between the sun gear 2S of the second planetary gear mechanism 2 and the case 6, and a third brake means B3 is disposed between the sun gear 2S of the second planetary gear mechanism 2 and the case 6.

These braking means B2. B3 may be a multi-disc brake, a band brake, or a combination of these and a one-way clutch, and these brake means B2. B3 and its braking means B2. B
Of course, an appropriate connecting member may be interposed between the member to be fixed by 3 or between the case 6 and the case 6.

An output shaft 5 that transmits rotation to a propeller shaft and a counter gear (not shown) is connected to the ring gear 2R of the second planetary gear mechanism 2 and the carrier 3C of the third planetary gear mechanism 3, which are connected to each other. ing.

Even in the automatic transmission having the configuration shown in FIG. 1, a plurality of gears can be set by appropriately engaging and disengaging each clutch means Kl, 4 and brake means B2, B3, and the control thereof Hydraulic control device C and electronic control unit (ECU) are used as control devices to perform
E is provided. The electronic control unit E is
It calculates the gear stage to be set based on input data such as vehicle speed v1 throttle opening θ, shift position signal, and cooling water temperature and outputs a signal to the hydraulic control device C. The following configuration can be adopted. The hydraulic control device c supplies and discharges hydraulic pressure to the clutch means and brake means to engage and release them, and operates the pressure regulating valve, the speed change control valve, and the speed change control valve. A conventionally known solenoid valve having a solenoid valve or the like can be used.

The gear stage set based on the output of the above control device is
In addition to the 5 main forward gears and reverse gears whose transmission ratios are close to a geometric series, 2nd and 5th gears, 3.2 gears, and 3.5 gears are added, resulting in a total of 8 forward gears and 1 reverse gear. , the operation table for setting these is shown in Table 1. In addition, the first
In the table, ○ marks indicate engagement, blank spaces indicate release, and * marks indicate engagement. Also ■.

The columns marked with numerals . . . indicate different engagement/disengagement patterns for setting the gear position.

Table 1 Although not specifically shown in Figure 1, in the automatic transmission described above, the drive (D)
Range, reverse (R) range 1, low (L) range,
A neutral (N) range or the like is selected, and the gear positions that can be set are limited for each range.

When a failure occurs in any of the clutch means or brake means, the control device consisting of the electronic control unit E and the hydraulic control device C performs control according to the flowchart shown in FIG. It has become.

That is, in FIG. 2, when a failure of the frictional engagement means is detected (step 1), it is determined whether the failure means that the frictional engagement means is stuck or slipping (step 2).
). Sticking of the frictional engagement means is an abnormal state in which the frictional engagement means remains in a state capable of transmitting torque even if pressure is released to release it, and slippage is an abnormal state in which the frictional engagement means remains in a state capable of transmitting torque. This is an abnormal condition in which it takes a long time to reach a sufficient torque transmission state even if hydraulic pressure is supplied. These abnormal conditions can be detected and determined by, for example, detecting the rotational speed of the input shaft 4, the output shaft 5, or a predetermined rotating member, and determining the degree of change thereof.

If the judgment result in step 2 is "slip", that is, if it takes time to reach a state where sufficient torque is transmitted, and if it is an abnormal state in which it can be released, proceed to step 3 and always release and always engage. Decide which is more advantageous. In other words, the gear range that can be set by always engaging or disengaging any one of the frictional engagement means described above can be found from Table 1, and if this is summarized, the following can be found. That's right.

■, Gear range in case of constant release ■1 always released in the first clutch means 4th gear, 5th gear, reverse gear.

■The second clutch means has two normally released 1st speed, 2nd and 5th speeds, 3rd speed, 3.5th speed, 4th speed, and reverse gear.

■Constant release of 3 in the 3rd clutch means 1st speed, 2nd speed, 2.5th speed, 3.2nd speed, 4th speed.

■The fourth clutch means has 4 normally released 2nd speed, 3rd speed, 3.2nd speed, 3.5th speed, 4th speed, and 5th speed.

- Constant release of second brake means B2 2.5th speed, 3rd, 2nd speed, 3.5th speed, 4th speed, 5th speed.

■Constant release of third brake means B3 1st gear, 2nd gear, 3rd gear, 4th gear, reverse gear.

③ Gear shift sequence in case of constant engagement ① Constant engagement of first clutch means Kl 1st speed, 2nd speed, 2.5th speed, 3rd speed, 3rd degree, 2nd speed 1.
3.5th gear, 4th gear.

■Constant engagement of 2 in the second clutch means 2nd speed, 3.2nd speed, 4th speed, 5th speed.

■3 constant engagement in the third clutch means 3rd gear, 3.5th gear, 4th gear, 5th gear, reverse gear.

■4 constant engagement in the 4th clutch means 1st gear, 2.5th gear, 4th gear, reverse gear.

■Constant engagement of second brake means B2 1st gear, 2nd gear, 3rd gear, reverse gear.

■Constant engagement of third brake means B3 2nd and 5th speed, 3.2nd speed, 3rd and 5th speed, 5th speed.

In this way, the gear ranges that can be set vary greatly depending on how the frictional engagement means with the so-called slippage abnormality is treated. Choose whether to release it. Here, as the driving condition serving as the selection criterion, the driving range selected by the above-mentioned shift lever can be adopted as an example. In other words, in the D range, it is required to be able to shift over the widest possible range from low gear to high gear, and in the L range, it is required to have as high torque as possible and engine braking. This means that it is required to be able to set the reverse gear in the R range. Therefore, when the D range is selected, it is required to set the forward gear in the widest possible range, and for this purpose, it is judged that it is preferable to engage the frictional engagement means with so-called slippage abnormality. If so,
Proceeding to step 4, hydraulic pressure is constantly supplied to the frictional engagement means having the abnormality to maintain it in the engaged state, and in this state, the gears are changed between settable gears (step 5). In this case, the speed change is also basically performed based on the engine load represented by the throttle opening and the vehicle speed.

To give a concrete example of constantly engaging the frictional engagement means with such an abnormality, if a so-called slipping abnormality occurs in the first clutch means 1 while the D range is selected, Since it is preferable to be able to change gears over as wide a range as possible, it has been determined that it is advantageous to always engage the first clutch means.
It is possible to set a gear sequence from 5th to 4th speeds.

On the other hand, if, for example, the R range is selected at the time of judgment in step 3 and it is necessary to set the reverse gear, and for that purpose it is necessary to release the frictional engagement means with the slippage abnormality, proceed to step 6 and remove the abnormality. Pressure is constantly discharged from a certain frictional retaining means to maintain it in a released state, and in this state, gears are changed between settable gears (step 7). To give a specific example, in the example regarding the first clutch means Kl, if the R range is selected by the shift lever, it is necessary to be able to set the reverse gear, so the first clutch means It is judged that it is advantageous to always release the gears, and the gears are changed according to the gear sequence consisting of the champion of the fourth gear, the fifth gear, and the reverse gear.

If the judgment result in step 2 is "stuck", that is, if there is an abnormality in which torque transmission is possible even after exhausting the pressure, proceed to step 4 and remove the frictional engagement means with the abnormality. It is always engaged, and in this state, the gears are changed according to the set gear sequence (step 5).

Another example of the required driving condition is the on/off of the overdrive switch. For example, if the second clutch has a so-called slippage abnormality, the overdrive switch is on at that time and high speed driving is required. If the overdrive switch is off and the overdrive gear is prohibited, then the second clutch means 2 is always engaged and the fifth gear, which is the overdrive gear, can be set. Conversely, if the overdrive switch is off and the overdrive gear is prohibited, the second 2 is constantly released from the clutch means to perform gear changes according to a gear sequence consisting of 1st speed, 2nd, 5th speed, 3rd speed, 35th speed, 4th speed, and reverse speed.

Next, another embodiment of the present invention will be described.
The figure is a skeleton diagram showing a gear train in a second embodiment of the present invention, and this gear train is a carrier 2C of the second planetary gear mechanism 2 and a carrier 2C of the third planetary gear mechanism 3 of the gear train shown in FIG. The fifth clutch means 5 is provided between the sun gear 3S, and the first brake means B1 is provided which can independently fix the sun gear 3S of the third planetary gear mechanism 3.The other configuration is the same as that shown in FIG. This is what I did. Table 2 shows the operation table of the automatic transmission equipped with this gear train.

(This page, the following margins) Table 2 Therefore, in the automatic transmission shown in Figure 3, if a so-called slippage abnormality occurs in any of the frictional engagement means, and the gear train is constantly engaged when it is constantly released. The gear shift sequence is as follows.

■, Gear range in case of constant release ■Constant release of first clutch means Kl 4th gear, 5th gear, reverse gear.

■The second clutch means has two normally released 1st speed, 2nd speed, 2.5th speed, 3rd speed, 35th speed, and 4th speed.
Speed, reverse gear.

■The third clutch means has 3 normally released 1st speed, 2nd speed, 2nd, 2nd speed, 2.5th speed, 2.7th speed, 32nd speed, and 4th speed.

■The fourth clutch means has 4 normally released 2nd speed, 2.2nd speed, 3rd speed, 3.2nd speed, 3.5th speed, 4th speed, and 5th speed.

■The fifth clutch means has five normally released 1st speed, 2nd speed, 2.2nd speed, 2.7th speed, 3rd speed, 4th speed, 5th speed, and reverse gear.

■ Constant release of the first brake means Bl 1st speed, 2nd speed, 2.5th speed, 3rd speed, 32nd speed, 3rd speed
．． 5th gear, 4th gear, 5th gear, reverse gear.

- Constant release of second brake means B2 1st speed, 2nd speed, 2.2nd speed, 2.5th speed, 2.7th speed, 3rd speed, 3.2nd speed, 3.5th speed , 4th speed, 5th speed,
Reverse stage.

■Always released third brake means B3 1st speed, 2nd speed, 2.7th speed, 3rd speed, 4th speed, reverse gear.

■, Gear shift sequence in the case of constant engagement ■1 always engaged in the first clutch means 1st speed, 2nd speed, 2.2nd speed, 2.5th speed, 27th speed,
3rd gear, 32nd gear, 3rd, 5th gear, 4th gear, 5th gear, reverse gear.

(2) Always engaged in the second clutch means 2nd speed, 2.2nd speed, 2nd, 7th speed, 3rd speed, 32nd speed, 4th speed, and 5th speed.

■3 constant engagement in the third clutch means 3rd gear, 3rd, 5th gear, 4th gear, 5th gear, reverse gear.

■ 4 constant engagements in the 4th clutch means 1st speed, 2nd speed, 25th speed, 2.7th speed, 3rd speed, 4th speed
Speed, reverse gear.

(5) Always engaged in the fifth clutch means 1st speed, 2nd speed, 2.5th speed, 3rd speed, 382nd speed, 3.5th speed, 4th speed, 5th speed, and reverse gear.

■ Constant engagement of the first brake means B1 in 1st speed, 2nd speed, 2.2nd speed, 2nd, 7th speed, 3rd speed,
4th gear, 5th gear, reverse gear.

■Constant engagement of second brake means B2 1st gear, 2nd gear, 3rd gear, reverse gear.

■ Constant engagement of the third brake means B3 in 2nd speed, 2.2nd speed, 2.5th speed, 3rd speed, 32nd speed,
35th speed, 5th speed.

Even in an automatic transmission equipped with the gear train shown in FIG. 3, the gear train that can be set in the case of a slippage abnormality in any of the frictional engagement means is such that the frictional engagement means with the abnormality is always engaged, or By constantly disengaging, the selection of the gear train changes as described above, and more specifically, the selection of the constant engagement and constant disengagement of the abnormal friction engagement means As in the first embodiment, this is done based on the required driving conditions.

FIG. 4 is a skeleton diagram showing a gear train in a third embodiment of the present invention, in which the ring gear 2R of the second planetary gear mechanism 2 is replaced by the ring gear 2R of the second planetary gear mechanism 2 in the configuration shown in FIG. 3 is connected to a ring gear 3R instead of the carrier 3C shown in FIG. 3, and the other configuration is as shown in FIG. The operation table is shown in Table 3.

(This page, blank spaces below) Table 3: In an automatic transmission equipped with the gear train shown in Fig. 4,
The following is a gear sequence that can be set by permanently engaging or disengaging the frictional engagement means due to slippage abnormality in any one of the frictional engagement means.

■, Gear range in case of constant release ■Constant release of first clutch means Kl 3rd gear, 4th gear, 4th, 5th gear, 5th gear, reverse gear.

■The second clutch means has two normally released 1st speed, 2nd speed, 2.5th speed, 3rd speed, 35th speed, and 4th speed.
Speed, reverse gear.

■The third clutch means has 3 normally released 1st speed, 2nd speed, 22nd speed, 2nd, 5th speed, 3rd speed, and 3rd speed.
, 2nd gear, 4th gear.

■The fourth clutch means has 4 normally released 2nd speed, 2.2nd speed, 3rd speed, 3.2nd speed, 3.5th speed, 4th speed, 4.5th speed, and 5th speed.

■The fifth clutch means has 5 normally released 1st speed, 2nd speed, 2.2nd speed, 3rd speed, 45th speed, and reverse gear.

■ Constant release of first brake means B1 1st speed, 2nd speed, 2.5th speed, 3rd speed, 32nd speed, 3rd speed
．． 5th gear, 4th gear, 5th gear, reverse gear.

■ Constant release of second brake means B2 1st speed, 2nd speed, 22nd speed, 2.5th speed, 3rd speed, 3rd speed
2nd gear, 3.5th gear, 4th gear, 45th gear, 5th gear, reverse gear.

■Constant release of third brake means B3 1st gear, 2nd gear, 3rd gear, 4th gear, reverse gear.

■, Gear shift sequence in the case of constant engagement; ■Always engaged first gear, second gear, 22nd gear, 2.5th gear, third gear, third gear of the first clutch means Kl
, 2nd speed, 3.5th speed, 4th speed.

■ Constant engagement of 2 in the second clutch means 2nd speed, 22nd speed, 3rd speed, 32nd speed, 4th speed, 4th speed.
5th gear, 5th gear.

- 3 constant engagement gears in the third clutch means: 3rd speed, 3.5th speed, 4th speed, 4.5th speed, 5th speed, and reverse gear.

■4 constant engagement in the 4th clutch means 1st gear, 2nd gear, 25th gear, 3rd gear, 4th gear, reverse gear.

■ Constant engagement of 5 in the 5th clutch means 1st speed, 2nd speed, 2.5th speed, 3rd speed, 32nd speed, 3rd speed
．． 5th gear, 4th gear, 5th gear, reverse gear.

- Constant engagement of first brake means B1: 1st speed, 2nd speed, 2.2nd speed, 3rd speed, 4th speed, reverse gear.

■Constant engagement of the second brake means 1st gear, 2nd gear, 3rd gear, reverse gear.

■ Constant engagement of the third brake means B3 2nd speed, 22nd speed, 2.5th speed, 3rd speed, 3.2nd speed,
35th speed, 4.5th speed, 5th speed.

Therefore, in the automatic transmission shown in FIG. 4 as well, it is possible to perform the same control as in the first and second embodiments described above to set a gear train according to the driving conditions.

Claims (1)

[Scope of Claims] In an automatic transmission equipped with a gear train that is set to a plurality of gear stages according to a combination of engagement and disengagement of a plurality of frictional engagement means, the automatic transmission is always engaged or always disengaged. When an abnormality in the frictional engagement means is detected, the required driving conditions are determined among the gear ranges that can be set by constantly engaging the frictional engagement means with the abnormality and the gear ranges that can be set by constantly disengaging the frictional engagement means. The present invention is characterized by comprising a control device that selects an advantageous gear range based on the above-mentioned information and constantly engages or disengages the abnormal friction engagement means so that the selected gear range can be set. Automatic transmission for vehicles.