JP2775951B2 - Automatic transmission for vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission for setting a shift speed by engagement / disengagement of a plurality of friction engagement means. There are a plurality of combinations of engagement / disengagement patterns of the engagement means, and any one of the combination patterns relates to an automatic transmission in which the rotational speed of the rotating member is different even if the set gear ratio is the same. It is.

2. Description of the Related Art An automatic transmission for a vehicle generally uses a plurality of sets of planetary gear mechanisms, connects predetermined rotating members among respective rotating members such as sun gears, ring gears, or carriers, and further includes any one of the following. In this configuration, a rotating member is selectively connected to an input shaft via clutch means, and any other rotating member is selectively fixed by a brake means, and an output shaft is further connected to another rotating member. In this type of automatic transmission, the number of shift stages that can be set depending on the number of planetary gear mechanisms to be used and the manner of connecting the respective rotating members, or the number and installation manner of frictional engagement means such as clutch means and brake means, etc. The gear ratio at each gear, or the number of revolutions of the rotating member, the load torque, and the like change in various ways, and there are an extremely large number of things that can be configured in principle. Even if it can be configured in principle, not all can be used practically, and practicality such as easy manufacturing, small size and light weight, excellent shift control, excellent durability, etc. It is never easy to create something that satisfies the requirements of For example, even in an automatic transmission in which three forward gear stages and five forward gear stages can be set using three sets of planetary gear mechanisms, the arrangement of frictional engagement means such as a clutch and the configuration of each planetary gear mechanism Depending on the gear ratio (the ratio of the number of teeth between the sun gear and the ring gear), the speed ratio in the reverse gear may be too large. In such an automatic transmission, the capacity of the friction engagement means is increased. Need
In addition, there is a problem that the durability of the friction engagement means and bearings is impaired.

As an automatic transmission which can solve such a problem, the present applicant uses three sets of single-pinion type planetary gear mechanisms, and in addition to five main forward speeds and one reverse speed, a so-called automatic transmission.
An automatic transmission capable of setting a plurality of intermediate speeds such as 2.2-speed, 2.5-speed, and 3.5-speed has already been proposed, and a control method thereof has been proposed in Japanese Patent Application No. 1-295823.

The automatic transmission is capable of setting 10 speeds forward and 1 speed reverse as a whole, including an intermediate speed, and is also capable of setting a predetermined speed such as a first speed, a second speed, or a third speed. There are a plurality of combinations of engagement / disengagement patterns of the friction engagement means, and among these patterns, there is a pattern in which the rotational speed of one of the rotating members is different even if the set speed ratio is the same. Therefore, when performing a shift to an adjacent shift speed or a so-called jump shift, etc., depending on the engagement / disengagement pattern to be selected, the rotation speed of the rotating member or the variable rotation speed accompanying the shift becomes large, or the jump speed is changed. In some cases, the so-called simultaneous speed change in which the cumulative fluctuating rotational speed of the rotating member increases or the frictional engagement means to be switched between the engaged and disengaged states becomes three or more depending on the intermediate stage that passes. is there. As described above, in the automatic transmission proposed by the present applicant, there are many types of shift patterns that can be selected. Therefore, in the method of Japanese Patent Application No. 1-295823 described above, the cumulative fluctuation rotation speed of the rotating member is small, and The jump shift is executed via the intermediate stage so as to reduce the number of friction engagement means to be switched between the engaged and disengaged states.

Problems to be Solved by the Invention However, in an automatic transmission having a plurality of types of engagement / disengagement patterns, if an engagement / disengagement pattern that avoids simultaneous shifting is selected, the fluctuating rotational speed of one of the rotating members increases,
Conversely, if an engagement / disengagement pattern in which the fluctuating rotational speed becomes small is selected, simultaneous shift may be inevitable. In such a case, in order to avoid a simultaneous shift and reduce the variable rotation speed, a shift via another shift speed is performed. However, if this type of shift control is always performed, friction There is a problem that the number of switching operations of the engagement means increases, and accordingly, control for shifting is complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an automatic transmission capable of simplifying a shift control and executing a shift with little effect on durability and shift shock. It is intended for.

Means to solve the problem, namely, durability and shift shock are affected by the actual rotation speed, and the actual rotation speed varies depending on the running state of the vehicle, and therefore, when the engine is running at high speed or the engine is running at high speed. However, even in the case of a shift pattern that cannot be executed in terms of durability, there is almost no effect on durability and the like when the vehicle is running at a low speed or the engine is running at a low speed. It is made by paying attention to the point. The automatic transmission according to the present invention includes a plurality of friction engagement means and a gear train set to a plurality of gears having different speed ratios depending on the engagement / disengagement state of the friction engagement means. In addition, in a vehicle automatic transmission having a plurality of types of patterns having the same speed ratio and different rotation speeds of rotating members as a combination pattern of engagement and disengagement of friction engagement means for setting a predetermined shift speed, When shifting to the predetermined gear, if the rotational speed of any of the rotating members is equal to or less than a predetermined value, the frictional engagement means increases the variable rotational speed of the predetermined rotating member to the predetermined gear. A frictional engagement means for setting the predetermined gear position and reducing the variable rotation speed of the predetermined rotation member if the rotation speed of any one of the rotation members is greater than a predetermined value. Union of engagement and release And it is characterized in that it comprises a control device that performs shift control to set the pattern.

In the automatic transmission according to the present invention, the shift is executed by the control device selecting the engagement / disengagement pattern of the friction engagement means for setting the shift speed. For a shift speed having a plurality of engagement / disengagement patterns in which the number of rotations of the rotating member is different, a selected pattern differs depending on conditions. That is, if the rotation speed of a predetermined rotating member such as an input shaft is equal to or less than a predetermined value, the speed is set in an engagement / disengagement pattern in which the variable rotation speed of any of the rotating members is large, and therefore, so-called simultaneous shifting It is possible to perform a shifting operation that is not necessary. On the contrary, if the rotation speed of a predetermined rotating member such as an input shaft exceeds a predetermined value, the shift speed is set with a small engagement / disengagement pattern of the variable rotation speed of any of the rotating members, Therefore, it is possible to perform a shift with little shift shock and without impairing durability. As a result, the simultaneous shift and the shift through the intermediate speed are limited to the case where the variable rotation speed is large, so that the shift control is facilitated.

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

In the example shown in FIG. 1, a gear train is mainly composed of three sets of single pinion type planetary gear mechanisms 1, 2, and 3. Each element in each of these planetary gear mechanisms 1, 2, and 3 is as follows. Are connected as shown in FIG. That is, the carrier 1C of the first planetary gear mechanism 1 and the ring gear 3R of the third planetary gear mechanism 3 are connected so as to rotate integrally, and the ring gear 2R of the second planetary gear mechanism 2 and the second planetary gear mechanism 3 And the carrier 3C are connected so as to rotate integrally. The sun gear 1S 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 K2, while the sun gear of the second planetary gear mechanism 2 is connected via the fourth clutch means K4. Connected to 2S and second
The carrier 2C of the planetary gear mechanism 2 is connected to the sun gear 3S of the third planetary gear mechanism 3 via fifth clutch means K5.

In addition, as a connection structure of the above-described components, a connection structure employed in a general automatic transmission such as a hollow shaft, a solid shaft, or an appropriate connecting drum can be employed.

The input shaft 4 is connected to an engine (not shown) via a power transmission means (not shown) such as a torque converter and a fluid coupling, and the input shaft 4 and the ring gear 1R of the first planetary gear mechanism 1 are connected to each other. In between, the first to selectively connect the two
A clutch means K1 is provided, and a third clutch means K3 for selectively connecting the input shaft 4 and the sun gear 1S of the first planetary gear mechanism 1 is provided between the input means 4 and the sun gear 1S.

The fourth clutch means K4 of the first to fifth clutch means K1 to K5 is constituted by a one-way clutch 20 and a multi-plate clutch 22 which are in parallel with each other, and the other clutch means are It is constituted by a multi-plate clutch. In addition, in practical use, there is a restriction on the arrangement of each constituent member, so that an appropriate intermediate member such as a connecting drum can be interposed as a connecting member for each clutch means K1, K2, K3, K4, K5. is there.

In addition, the third planetary gear mechanism 3 serves as brake means for preventing rotation of the rotating members in the planetary gear mechanisms 1, 2, and 3 described above.
The first brake means B1 for selectively blocking the rotation of the sun gear 3S, the second brake means B2 for selectively blocking the rotation of the carrier 2C of the second planetary gear mechanism 2, and the sun gear of the second planetary gear mechanism 2 Third brake means B3 for selectively preventing rotation of 2S and fourth brake means B4 for selectively preventing rotation of sun gear 1S of first planetary gear mechanism 1 are provided. Among these braking means, the first braking means B1
A one-way clutch 40 provided between a sun gear 3S of the third planetary gear mechanism 3 and a transmission case (hereinafter simply referred to as a case) 6 and a band brake 42 in a parallel relationship with the one-way clutch 40. The second brake means B2 is a multi-disc brake, and the 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 B1, B2, B3, B4
Needless to say, a suitable connecting member can be interposed between the case 6 and each element to be fixed by the brake means B1, B2, B3, B4 or the case 6.

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

In the automatic transmission having the configuration shown in FIG.
The first reverse speed is the main shift speed, which includes the second forward speed and the third forward speed.
So-called 2.2th, 2.5th, and 2.7th speeds are added between the first and second speeds, and so-called 3.2th and 3.5th speeds are added between the third and fourth speeds. In principle, it is possible to set 10 speeds and 1 reverse speed.
At other shift speeds except the 2.7th, 3.2th and 3.5th speeds, there are a plurality of combinations of engagement / disengagement of clutch means and brake means (so-called engagement / release patterns) for setting the shift speed. It is the first set if it is shown as an operation table.
It is as shown in the table. In addition, the rotation speed of the rotation element of each planetary gear mechanism 1, 2, 3 in each engagement / disengagement pattern is
Table 2 shows the ratio when the number of rotations of the input shaft 4 is "1". In Table 1, a circle indicates that the vehicle is engaged, a blank indicates that the vehicle is released, and an asterisk indicates that the vehicle may be engaged. The gear ratio and the rotation state do not change even when released, such as the five-clutch means K5 and the first brake means B1, but if the clutch is released like the first brake means B1 in the pattern in the column b of the fourth speed, The fourth clutch means in the pattern in the column b of the second speed, wherein the speed ratio does not change but the rotation state changes.
This includes those in which the gear ratio and the rotation state do not change even if other * -marked means such as K4 and the third brake means B3 are engaged even if they are released. In Tables 1 and 2, a, b, and a in the second, third, fourth, fifth, and reverse gears are shown.
The columns with c symbols indicate the engagement / release patterns of the engagement / disengagement patterns for setting the gears, in which the rotation speeds of the rotating elements of the planetary gear mechanism are different. ,... Represent the types of the engagement / disengagement patterns although the rotation speeds of the rotating elements of the planetary gear mechanism are not different.

Table 1 shows the gear positions that can be set in principle. In practical use, a gear position that is superior in terms of power performance and acceleration performance is selected from these gear positions. In other words, the gears whose gear ratios are close to the geometric series are selected as the main gears, and as the engagement / disengagement pattern for setting each gear. From those listed in Table 1, those that are advantageous in terms of shift controllability and durability are selected. In the example shown in FIG. 1, each of the fourth clutch means K4 and the first brake means B1 is
Since the fourth clutch means K4 is in the engagement state, the relative rotation direction between the sun gear 1S of the first planetary gear mechanism 1 and the sun gear 2S of the second planetary gear mechanism 2 is a one-way clutch. If the direction of engagement of the one-way clutch 20 is maintained, the one-way clutch 20 is used to maintain the engaged state. To engage the fourth clutch means K4. The same applies to the first brake means B1, and the sun gear 3S of the third planetary gear mechanism 3
If the rotation direction is the direction in which the one-way clutch 40 is engaged, the one-way clutch 40 is engaged to
Is engaged, and if the relative rotation direction, such as the need for engine braking, is the direction in which the one-way clutch 40 is released, the multiple disc brake 42 is engaged to bring the first brake means B1 into the engaged state. .

In the automatic transmission shown in FIG. 1 as well, the setting of each speed shown in Table 1 is performed according to the engine load represented by the throttle opening and the vehicle speed, similarly to the conventional automatic transmission. A hydraulic control device C for supplying and discharging a hydraulic pressure for engaging and disengaging the clutch means and the brake means with respect to each of the clutch means and the brake means, a vehicle speed V, a throttle opening θ or a shift position, and a traveling mode select signal. , Hydraulic control device C based on input data such as oil temperature
And an electronic control unit (ECU) E for outputting an electric instruction signal to the electronic control unit.

The control device including the hydraulic control device C and the electronic control unit E sets the gear position based on running conditions such as the vehicle speed V and the throttle opening θ.
For gears with multiple types of engagement / disengagement patterns,
The engagement / disengagement pattern is selected according to the conditions at the time of shifting, and the gear stage is set.

This is specifically described as follows. That is, if the vehicle speed increases or the throttle opening decreases while traveling in the third speed, the shift to the fifth speed is determined in accordance with the degree thereof, and in this case, a selectable engagement / release pattern can be selected. There are three types of patterns as shown in Tables 1 and 2. In the automatic transmission shown in FIG. 1 as a reference for selecting the engagement / disengagement pattern for setting the fifth speed, a predetermined rotating member, for example, the number of rotations of the input shaft 4 is adopted, and the selection is made according to the magnitude thereof. Different engagement / release patterns.
That is, in FIG. 2, when the shift to the fifth speed is determined while the vehicle is traveling with the third speed set in the pattern of column d of Table 1 (step 1), the rotation speed of the input shaft 4 is determined. It is determined whether Ni is equal to or less than a predetermined value α (step 2).
Here, the reference value α is a value determined in consideration of the durability of the rotation rate forming the gear train, and may be a constant or a variable that changes according to conditions such as oil temperature. It may be. If the decision result in the step 2 is "Yes", the process proceeds to a step 3, and the engagement / disengagement pattern is set to the engagement / release for setting the fifth speed from the pattern in the column d where the third speed is set. An output for changing the pattern to the pattern in column b or the pattern in column c of Table 1 is performed. That is, if the determination result in step 2 is “yes”, it is determined that the rotation speed of the rotating member in the gear train does not affect the durability, and the engagement / release pattern output in this case is Although the pattern is not a simultaneous shift, the rotation speed of the ring gear 1R of the first planetary gear mechanism 1 or the sun gear 3S of the third planetary gear mechanism 3 is twice or more the rotation speed of the input shaft 4.
Specifically, the patterns in the d column of the third speed are the first to third patterns.
Is a pattern that can engage the first clutch means B1 with the clutch means K1 to K3, whereas the pattern in the column c of the fifth speed is the first to third clutch means K1.
~ K3 and the third brake means B3 are engaged, so that the shift can be executed by performing the release of the first brake means B1 and the engagement of the third brake means B3 in parallel. If the fifth speed is set by the pattern in column c, this pattern is a pattern that can engage the second clutch means K2, the third clutch means K3, the first brake means B1, and the third brake means B3. Therefore, the shift from the third speed can be executed by disengaging the first clutch means K1 and engaging the third brake means B3. Therefore, in either case, shifting can be performed by switching the engagement / disengagement state of the two frictional engagement means. In other words, since simultaneous shifting is not performed, control for shifting is easy. Further, in this case, as is known from Table 2, the rotation speed of the ring gear 1R of the first planetary gear mechanism 1 and the sun gear 3S of the third planetary gear mechanism 3 is more than twice the rotation speed of the input shaft 4, and therefore, Although the fluctuating rotational speed increases, the actual rotational speed and actual fluctuating rotational speed of the ring gear 1R and the sun gear 3S do not become large enough to affect the durability because the rotational speed of the input shaft 4 is low. Does not occur.

After outputting the pattern for the above-mentioned shift in step 3, it is determined in step 4 following whether or not the shift to the fifth speed has been completed. Is changed to "yes", the pattern for setting the fifth speed is changed from the pattern in column b or c to the pattern in column a (step 5), and the scanning process returns. As a result, the number of rotations of each rotating member in the state of the fifth speed is reduced, which is more advantageous for improving durability and preventing an increase in oil temperature and the like.

On the other hand, if the result of the determination in step 2 is "NO", a shift is performed in which the fifth speed is set in the pattern in the column a.
That is, if the result of the determination in step 2 is “No”, the rotational speed of the input shaft 4 is large.
To output the fifth speed set by the pattern in the column a. As can be seen from Table 2, the pattern in the column a of the fifth speed is about 1.83 times the rotation speed of the input shaft 4 even if the rotation speed of each rotating member is the largest, and the rotation speed of the input shaft 4 is the actual rotation speed. Even if the number of rotations of the rotating member of the gear train increases as the number increases, the variable rotation number of the rotating member does not become large enough to worsen the shift shock and does not adversely affect durability. . Since the pattern in the column a of the fifth speed is a pattern in which the second clutch means K2, the third clutch means K3, and the third brake means B3 are engaged, the gear can be directly shifted from the pattern in the column d of the third speed. If you do,
Since the first clutch means K1 and the first brake means B1 are disengaged and the third brake means B1 is engaged, the number of frictional engagement means for switching the engagement / release state becomes three or more. , So-called simultaneous shifting. To avoid this, the fourth speed may be set once, and then the fifth speed may be set according to the pattern in the 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 shift speed is changed according to the magnitude of the rotation speed of the input shaft 4, so that the so-called simultaneous shift and the shift via the intermediate speed are always performed. Since there is no need to perform the shift, the shift control is facilitated.

The present invention is not limited to the configuration shown in FIG. 1, but can be applied to an automatic transmission having another configuration. That is, as is known from Tables 1 and 2, the fourth brake means B4 may be engaged at the second speed and the 2.5th speed, but these gears do not engage the fourth brake means B4. Therefore, even if the fourth brake means B4 is eliminated from the configuration shown in FIG. 1, all the shift speeds shown in Table 1 can be set, and therefore, the present invention is not limited to the configuration shown in FIG. It can also be applied to a configuration in which the means B4 is abolished. Other examples to which the present invention can be applied include, for example, Japanese Patent Application Nos. 1-185151, 1-185152, 1-186991, and 1-18991, filed by the present applicant. 1-1869
No. 92, Japanese Patent Application No. 1-205478, Japanese Patent Application No. 280957, etc., as in each configuration described in the specification and drawings, there are multiple engagement / disengagement patterns for setting any one of the gear positions. There are various types of automatic transmissions.

In the above-described embodiment, the engagement / disengagement pattern to be selected is changed based on the rotation speed of the input shaft. However, the rotation member to be used as a criterion is a rotation member other than the input shaft, for example, an output shaft or the like. It may be a rotating element of any of the planetary gear mechanisms.

Advantageous Effects of the Invention As is clear from the above description, in the automatic transmission according to the present invention, when the actually generated variable rotational speed is large, a so-called simultaneous shift or a shift via an intermediate gear is performed, and on the contrary, the automatic shift is actually performed. When the resulting fluctuating rotation speed is small, the shift is performed by selecting an engagement / disengagement pattern that does not result in a simultaneous shift even if the fluctuation ratio of the rotation speed is large. It is not the same, and it is possible to select an advantageous one as needed. Therefore, according to the present invention, it is possible to facilitate the shift control, and it is particularly possible to reduce the shift shock and the durability. To prevent.

[Brief description of the 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 shift control method executed by the automatic transmission. 1,2,3 ... Planetary gear mechanism, 1S, 2S, 3S ... Sun gear, 1C, 2
C, 3C carrier, 1R, 2R, 3R ring gear, 4 input shaft, 5 output shaft, C hydraulic control unit, E electronic control unit.

────────────────────────────────────────────────── (5) References JP-A-64-35147 (JP, A) JP-A-64-58839 (JP, A) JP-A-3-181670 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) F16H 59/00-63/48

Claims (1)

(57) [Claims] The present invention has a plurality of friction engagement means and a gear train which is set to a plurality of gears having different speed ratios according to the engagement / disengagement state of the friction engagement means, and In the automatic transmission for a vehicle, in which there are a plurality of types of patterns having the same speed ratio and different rotation speeds of a rotating member as a combination pattern of engagement / disengagement of friction engagement means for setting a shift speed, At the time of shifting to a gear, if the rotation speed of any of the rotating members is equal to or less than a predetermined value, the predetermined speed is changed to the engagement of the friction engagement means in which the variable rotation speed of the predetermined rotating member becomes large. If the rotational speed of any one of the rotating members is set to a combination pattern of release and the rotational speed of any of the rotating members is larger than a predetermined value, the predetermined shift speed is changed to a variable rotational speed of the predetermined rotating member. Set with the release combination pattern An automatic transmission for a vehicle, comprising a control device for performing a shift control as described above.