JPH03213758A - Automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To facilitate the variable speed control by performing the concurrent change-gear or change-gear through intermediate stages when the fluctuated rotating speed is high, and reversely when the fluctuated rotating speed is low, selecting an engagement/release pattern for avoiding the concurrent change-gear. CONSTITUTION:In an automatic transmission which consists of a first - a third epicyclic gear mechanism 1 - 3, clutches K1 - K4 and brakes B1 - B4 are selectively engaged/released to perform the predetermined change-gear. In this case, when the rotating speed of the predetermined rotating member such as an input shaft 4 is less than the preset value, a variable speed stage is set with an engagement/release pattern, that the fluctuated rotating speed of any one of rotating members is high, to perform the change-gear for avoiding the concurrent change-gear. Reversely, when the rotating speed of the predetermined rotating member such as the input shaft 4 exceeds the preset value, the concurrent change-gear or change-gear through intermediate stages is performed with an engagement/release pattern that the fluctuated rotating speed of any one of rotating member is low. Variable speed control is thereby facilitated, and while deterioration of a change-gear shock and lowering of the durability can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an automatic transmission that sets gears by engaging and disengaging a plurality of frictional engagement means. This relates to an automatic transmission in which there are multiple types of combination patterns for engagement and release of the coupling means, and in any of these combination patterns, even if the set gear ratio is the same, the rotation speed of the rotating member is different. It is.

Conventional automatic transmissions for vehicles generally use multiple sets of planetary gear mechanisms to connect predetermined rotating members such as sun gears, ring gears, or carriers, and to The rotary member is selectively connected to the input shaft via a clutch means, and one of the other rotary members is selectively fixed by a brake means, and the output shaft is further connected to the other rotary member. In this type of automatic transmission, the number of gear stages can be set depending on the number of planetary gear mechanisms used, the way each rotating member is connected, or the number and installation method of friction engagement means such as clutch means and brake means. Gear ratio at each gear stage,
Alternatively, the number of rotations of the rotating member, the load torque, etc. vary, and there are an extremely large number of possible configurations in principle. Even if it is configurable in principle, not all of them can be put to practical use, but practical aspects such as being easy to manufacture, being small and lightweight, having excellent speed change controllability, and being excellent in durability are important. It is by no means easy to create something that satisfies the demands of the world. For example, even in an automatic transmission that uses three sets of planetary gear mechanisms to set five forward gears and one reverse gear, there are problems with the arrangement of frictional engagement means such as clutches, and the difference between each planetary gear mechanism. Depending on how the gear ratio (the ratio of the number of teeth between the sun gear and the ring gear) is selected, the gear ratio in reverse gear may become too large, so in such automatic transmissions, the capacity of the friction engagement means should be increased. Moreover, there is a problem that the durability of the frictional engagement means, bearings, etc. is impaired.

The present applicant has developed an automatic transmission that can solve these problems by using three sets of single-binion planetary gear mechanisms, in addition to five main forward speeds and one reverse speed.
．． An automatic transmission capable of setting a plurality of intermediate speeds such as 2nd speed, 2.5th speed, or 35th speed has already been proposed, and a control method thereof has been proposed in Japanese Patent Application No. %1-295823.

In addition to being able to set a total of 10 forward gears and 1 reverse gear including intermediate gears, the automatic transmission can also set a predetermined gear such as 1st, 2nd, or 3rd gear. There are a plurality of combination patterns of engagement and release of the frictional engagement means, and among these patterns, there are patterns in which the rotational speed of one of the rotating members differs even if the set gear ratio is the same. Therefore, when shifting to an adjacent gear or performing a so-called jump shift, depending on the engagement/disengagement pattern selected, the rotational speed of the rotating member and the fluctuation of the rotational speed due to the shift may become large, or the jump shift may increase. Depending on the intermediate stages that are passed through during the process, the cumulative rotational speed fluctuation of the rotating member may become large, and furthermore, so-called simultaneous gear shifting may occur where there are three or more frictional engagement means that must be switched between engaged and disengaged states. be. As described above, in the automatic transmission already proposed by the present applicant, there are many types of selectable shift patterns, and therefore, the method of the above-mentioned Japanese Patent Application No. 1-295823 has a method in which the cumulative fluctuation of the rotational speed of the rotating members is small, and In order to reduce the number of frictional engagement means that must be switched between engaged and disengaged states, it was decided to execute the jump shift via the intermediate stage.

Problems to be Solved by the Invention However, in automatic transmissions that have multiple types of engagement/disengagement patterns, if an engagement/disengagement pattern that avoids simultaneous gear shifting is selected, the fluctuation in the rotational speed of one of the rotating members will increase, or the opposite If an engagement/disengagement pattern is selected in which the rotational speed fluctuation is small, simultaneous gear shifting may be necessary.

In such a case, in order to avoid simultaneous gear shifts and reduce the rotating speed fluctuation, the gear shift should be performed via another gear stage, but if this type of shift control is always performed, friction The number of switching operations of the engagement means increases,
Accordingly, there is a problem in that the control for shifting becomes complicated.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an automatic transmission that simplifies the control for shifting and can execute shifting with less influence on durability and shift shock. The purpose is to

The means to solve the problem, that is, the durability and speed change stability, are affected by the actual rotation speed, and the actual rotation speed changes depending on the driving condition of the vehicle. Therefore, when driving at high speed or when the engine is running at high speed Even if the shift pattern is impractical in terms of durability, it has almost no effect on durability when the engine is running at low speed or when the engine is running at low speed. This was done by focusing on this point. The automatic transmission of the present invention includes a plurality of frictional engagement means and a gear train that is set to a plurality of gears with different gear ratios depending on the engagement/disengagement state of these frictional engagement means. An automatic transmission for a vehicle, which has a plurality of combination patterns of engagement and release of frictional engagement means for setting a predetermined gear stage, with the same gear ratio and different rotational speeds of rotating members. When shifting to the predetermined gear, if the rotational speed of any rotating member is less than or equal to a predetermined value, the predetermined gear is changed to a friction coefficient that increases the varying rotational speed of the predetermined rotating member. If the combination pattern of engagement and release of the coupling means is set, and the rotational speed of any rotating member is larger than a predetermined value, the predetermined gear is changed to a friction coefficient that reduces the fluctuating rotational speed of the predetermined rotating member. The present invention is characterized in that it includes a control device that performs speed change control to set a combination pattern of engagement and release of the coupling means.

Function: In the automatic transmission of the present invention, the control device selects the engagement/disengagement pattern of the frictional engagement means to set the gear stage to execute the gear shift, but even if the gear ratio is the same, For a gear stage that has a plurality of engagement/disengagement patterns in which the rotational speed of one of the rotating members is different, the selected pattern differs depending on the conditions. In other words, if the rotational speed of a predetermined rotational member such as an input shaft is less than a predetermined value, the gear stage is set with an engagement/release pattern in which the varying rotational speed of one of the rotational members is large, thus resulting in so-called simultaneous shifting. It is possible to change gears without having to do so. On the other hand, if the rotation speed of a predetermined rotating member such as an input shaft exceeds a predetermined value,
The gear stage is set using an engagement/release pattern with a small variation in the rotational speed of any of the rotating members, so that gear changes can be performed with less gear shift shock and without impairing durability.

As a result, simultaneous gear shifting and gear shifting via intermediate gears are limited to cases where the varying rotational speed is large, making gear shift control easier.

Embodiments Next, embodiments of the present invention will be described in detail based on 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 via a fifth clutch means 5.

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 input 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 are connected to each other. In between, there is a first
A clutch means 1 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.

Of the first to fifth clutch means Kl, to 5, the fourth clutch means 4 is constituted by a one-way clutch 20 and a multi-disc clutch 22 which are in a parallel relationship with each other, and the other clutch means The means is constituted by a multi-disc clutch. In addition, in practical use, since there are restrictions on the arrangement of each component, each clutch means Kl has 2.
3. Of course, a suitable intermediate member such as a connecting drum may be interposed as a connecting member for 4 and 5.

Further, as a brake means for preventing the rotation of the rotating members in the above-mentioned planetary gear mechanism 1.2.3, a first brake means B1 for selectively preventing rotation of the sun gear 3S of the third planetary gear mechanism 3, and a second A second brake means B2 that selectively blocks the rotation of the carrier 2C of the gear mechanism 2, a third brake means B3 that selectively blocks the rotation of the sun gear 2S of the second planetary gear mechanism 2, and a first planetary gear mechanism. 4th brake means B4 for selectively blocking rotation of sun gear IS 1;
and is provided. The first of these braking means
The brake means B1 is a sun gear 3 of the third planetary gear mechanism 3.
A one-way clutch 40 provided between S and a transmission case (hereinafter simply referred to as a case) 6, and a band brake 4 in parallel with this one-way clutch 40.
2, and the second brake means B
2 is a multi-disc brake, and a third brake means B3
And the fourth brake means B4 are each constituted by a band brake. In addition, in practical use, these brake means Bl, B2°B3. B4 and these brake means Bl, B2°B3. Of course, an appropriate connecting member can be interposed between each element to be fixed by B4 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.

The automatic transmission with the configuration shown in FIG. 1 has five forward speeds and one reverse speed as the main gears, and between the second forward speed and the third forward speed there are so-called 2.2 speed and 2.2 speed. 10 forward speeds and 1 reverse speed with the addition of 5th speed, 2.7th speed, and so-called 3rd and 2nd speeds and 3rd and 5th speeds between the 3rd and 4th forward speeds.
In principle, it is possible to set the gears of 2nd, 2nd, 2.7th, 3.2nd and 3.5th.
For other gears other than the above gears, there are multiple combinations of engagement and release (so-called engagement and release patterns) of the clutch means and brake means to set the gear, and these can be shown as an operation table. As shown in Table 1. Also, each planetary gear mechanism 1.2 in each engagement/release pattern.
Table 2 shows the rotational speed of the rotating element No. 3 as a ratio when the rotational speed of the input shaft 4 is set to "1".

In Table 1, the 0 mark indicates engagement, the blank indicates disengagement, and the * mark indicates that it may be engaged. 5 Clutch means 5, first brake means B1, etc. that do not cause a change in the gear ratio or rotational state even if released, 4th speed b
When released, like the first brake means B1 in the pattern in column b, the gear ratio does not change but the rotation state changes, and when the fourth clutch means in the pattern in column b in the second gear is released, This includes cases where the gear ratio and rotational state do not change even if the other means marked with an asterisk (*) are engaged and released. Also, in Tables 1 and 2, a
, b, c... are the engagement/disengagement patterns for which the rotational speed of the rotating element of the planetary gear mechanism differs among the engagement/disengagement patterns for setting the relevant gear. Furthermore, the symbols ■, ■, ■, etc. represent the types of engagement/disengagement patterns even though the rotational speeds of the rotating elements of the planetary gear mechanism do not differ.

Table 2 Table 1 shows the gears that can be set in principle.
In practical use, the gears that are superior in terms of power performance and acceleration must be selected and set from among these gears, and specifically, the gear ratio should be close to a geometric series. The related gear will be selected as the main gear,
Further, as the engagement/disengagement pattern for setting each gear stage, one that is advantageous in terms of shift controllability, durability, etc. is selected from among those listed in Table 1. Further, in the example shown in FIG. 1, each of the fourth clutch means 4 and the first brake means B1 is connected to the one-way clutch 20
．． 40, the fourth clutch means has a
The engaged state is determined by the one-way clutch 20 if the relative rotational direction of the sun gear IS of the first planetary gear mechanism 1 and the sun gear 2S of the second planetary gear mechanism 2 is in the direction in which the one-way clutch 20 engages. If the relative rotation direction is in the direction in which the one-way clutch 20 is released, such as when engine braking is required, the multi-disc clutch 22 is engaged and the fourth clutch means is set to the engaged state. do. Also the first
The same applies to the brake means Bl, and the rotation direction of the sun gear 3S of the third planetary gear mechanism 3 is the same as that of the one-way clutch 4.
0, the one-way clutch 40 is engaged and the first brake means B1 is engaged, and the one-way clutch 40 is released when the relative rotation direction is such that engine braking is required. If it is in the direction, the multi-disc brake 42 is engaged to bring the first brake means B1 into an engaged state.

In the automatic transmission shown in Fig. 1, the setting of each gear stage shown in Table 1 is made according to the engine load represented by the throttle opening and the vehicle speed, as in conventional automatic transmissions. The control means includes a hydraulic control device C that supplies and discharges hydraulic pressure to engage and release each of the clutch means and brake means, and a vehicle speed V, throttle opening θ, shift position, and driving mode select signal. , and an electronic control unit (ECU) E that outputs electrical instruction signals to the hydraulic control device C based on input data such as oil temperature.

The control device consisting of the hydraulic control device C and the electronic control unit E sets the gear stage based on driving conditions such as the vehicle speed V and the throttle opening θ. Regarding gears, the engagement/disengagement pattern is selected depending on the conditions at the time of gear shifting to set the gear.

A concrete explanation of this is as follows.

In other words, if the vehicle speed increases or the throttle opening decreases while driving in 3rd gear, a shift to 5th gear is determined depending on the degree of the increase, and in that case, selectable engagement/disengagement patterns are used. There are three types of patterns as shown in Tables 1 and 2. In the automatic transmission shown in FIG. 1, the number of rotations of a predetermined rotating member, for example, the input shaft 4, is used as the selection criterion for the engagement/disengagement pattern for setting the fifth speed, and selection is made according to the size of the rotation number. Different engagement/release patterns. In other words, in Figure 2, 3rd speed is dWJ in Table 1.
When it is determined to shift to 5th gear while driving with the pattern set (step 1), the rotation speed N of the input shaft 4
It is determined whether or not i is less than or equal to a predetermined value α (step 2). The reference value α here is a value determined by considering the durability of the rotating members that make up the gear train, and may be a constant or a variable that changes depending on conditions such as oil temperature. It may be. If the judgment result in step 2 is "yes", proceed to step 3 and change the engagement/release pattern to set the 5th speed from the pattern in column d, which sets the 3rd speed. Output is performed to change the pattern to the pattern in column b or the pattern in column C of Table 1. In other words, if the determination result in step 2 is "yes", it means that the rotational speed of the rotating member in the gear train is determined to be a rotational speed that does not affect durability, and the engagement/disengagement pattern output in this case is a pattern in which the speeds do not change simultaneously, but the rotational speed of the ring gear IR of the first planetary gear mechanism 1 or the sun gear 3S of the third planetary gear mechanism 3 is more than twice the rotational speed of the input shaft 4. Specifically, the pattern in column d for the third speed is a pattern in which the first to third clutch means 1 to 3 can be engaged with the first brake means B1,
On the other hand, the pattern in column C for the fifth speed is a pattern in which the first to third clutch means 1 to 3 are engaged with the third brake means B3, so the shift is performed by the first brake means. This can be carried out by releasing Bl and engaging the third brake means B3 in parallel. Also, set 5th gear to C.
If the pattern in the column is used, this pattern is a pattern in which the second clutch means is engaged with 2, the third clutch means is engaged with 3, the first brake means B1 and the third brake means B3 are engaged. Shifting from the third speed can be performed by releasing the first clutch means Kl and engaging the third brake means B3. Therefore, in any case, the speed can be changed by switching between the engaged and disengaged states of the two frictional engagement means.In other words, since simultaneous speed changes do not occur, control for speed changes is easy. Also, in this case, as known from Table 2, the ring gear IR of the first planetary gear mechanism 1 and the third
The rotational speed of the sun gear 3S of the planetary gear mechanism 3 is more than twice the rotational speed of the input shaft 4, and therefore the fluctuation of the rotational speed becomes large, but since the rotational speed of the input shaft 4 is low, these ring gear IR and sun gear The actual rotational speed and actual fluctuation rotational speed of 3S are not large enough to affect durability, and no noticeable shock occurs.

After outputting the above-mentioned shift pattern in step 3, in step 4 that follows, it is determined whether or not the shift to 5th gear has been completed, and the end of the shift is determined by the result of the judgment in step 4. When the answer is "Yes", change the pattern for setting the 5th gear from the pattern in column b or column C to a.
Output to change the pattern to llll (step 5)
), the scanning process returns. As a result, the rotational speed of each rotating member in the fifth speed state is lowered, which is more advantageous in improving durability and preventing an increase in oil temperature.

On the other hand, if the determination result in step 2 is "no", a shift is performed to set the fifth speed according to the pattern in column a. That is, if the determination result in step 2 is "no", the rotation speed of the input shaft 4 is high, so in this case, the process proceeds to step 6 and outputs to set the fifth speed according to the pattern in column a. As is known from Table 2, the pattern in column a for the 5th speed is that even if the maximum rotation speed of each rotating member is about 1.83 times the rotation speed of the input shaft 4, the rotation speed of the input shaft 4 is Even if the rotational speed of the rotating members of the gear train increases as the actual rotational speed increases, the fluctuating rotational speed of the rotating members does not become so large as to worsen shift shock, and the durability is not adversely affected. Nor. Note that this 5th speed all pattern is a pattern in which the second clutch means is engaged with 2, the third clutch means is engaged with 3, and the third brake means B3 is engaged, so the shift can be performed directly from the pattern of column d of 3rd speed. 1 and the first brake means B to the first clutch means.
Since the third brake means Bl is engaged at the same time as the third brake means Bl is released, the number of frictional engagement means to be switched between the engaged and disengaged states becomes three or more, resulting in so-called simultaneous gear shifting. To avoid this - first set 4th gear, then 5th gear.
Shift control may be performed to set the speed according to the pattern in column a.

After performing the above output in step 6, the scanning process returns.

Therefore, in the automatic transmission shown in Fig. 1, the engagement/disengagement pattern for setting the gear stage is changed depending on the rotational speed of the input shaft 4, so that so-called simultaneous shifting or shifting via an intermediate gear is always performed. Since there is no need to execute this, shift control becomes easier.

Note that this invention is not limited to the configuration shown in FIG. 1 above,
It can also be applied to automatic transmissions with other configurations.

That is, as is known from Tables 1 and 2, the fourth
Although the brake means B4 may be engaged at 2nd speed and 2.5th speed, these gears can be set without engaging the fourth brake means B4. 4 Even if the brake means B4 is abolished, all the gears shown in Table 1 can be set, so this invention
The present invention can also be applied to a configuration in which the fourth brake means B4 is eliminated from the configuration shown in the figure. Other examples to which this invention can be applied include, for example, Japanese Patent Application No. 1-185151, Japanese Patent Application No. 1-185152, Japanese Patent Application No. 1-186991, which the present applicant has already filed. No. 1-186992,
As shown in the specifications and drawings of Japanese Patent Application No. 1-205478 and Japanese Patent Application No. 1-280957, there are multiple types of engagement/disengagement patterns for setting one of the gears. One example is the transmission.

Furthermore, in the embodiment described above, the engagement/disengagement pattern to be selected is changed based on the rotation speed of the input shaft.
Rotating members that should be used as judgment criteria include rotating members other than the input shaft,
For example, it may be an output shaft or a rotating element of any planetary gear mechanism.

Effects of the Invention As is clear from the above explanation, in the automatic transmission of the present invention, when the actual rotating speed fluctuation is large, so-called simultaneous gear shifting or gear shifting via an intermediate gear is performed; When the resulting rotational speed fluctuation is small, an engagement/release pattern that does not result in simultaneous gear shifting is selected and shifted even if the rotational speed fluctuation ratio is large. Therefore, the engagement/release pattern selected during gear shifting is always They are not the same, but an advantageous one can be selected as needed. Therefore, in this invention, it is possible to facilitate shift control, and in particular, it can be prevented from worsening shift shock or reducing durability. It can be prevented.

[Brief explanation of drawings]

FIG. 1 is a skeleton diagram showing the principle of an embodiment of the present invention, and FIG. 2 is a flowchart showing an example of a speed change control method executed in the automatic transmission. 1.2.3...Planetary gear mechanism, IS, 2S, 3S・
...Sun gear, IC, 2C, 3C...Carrier,
IR, 2R, 3R...Ring gear, 4...Input shaft, 5...Output shaft, C...Hydraulic control device, E.
...Electronic control unit.

Claims (1)

[Claims] A plurality of frictional engagement means and the engagement and engagement of these frictional engagement means.
It has a gear train that is set to a plurality of gears with different gear ratios depending on the release state, and a gear ratio as a combination pattern of engagement and disengagement of the frictional engagement means to set a predetermined gear. In a vehicle automatic transmission in which there are multiple types of patterns in which the number of rotations is the same and the number of rotations of rotating members is different, the number of rotations of any one of the rotating members is less than or equal to a predetermined value when shifting to the predetermined gear position. If so, the predetermined gear stage is set with a combination pattern of engagement and disengagement of the frictional engagement means that increases the fluctuating rotational speed of the predetermined rotating member, and the rotational speed of one of the rotating members is a predetermined value. If the rotational speed is larger than the above, the predetermined gear is further provided with a control device that performs gear change control so as to set the predetermined gear stage with a combination pattern of engagement and release of the frictional engagement means that reduces the fluctuating rotational speed of the predetermined rotating member. automatic transmission for vehicles.