JPH03181670A - Automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To improve the durability of an automatic transmission for vehicle by setting the engaging/releasing pattern of a small number of friction engaging means subjected to switching operation, in a speed change, and changing the pattern when the rotational frequency of the rotary member is increased more than a specific standard value. CONSTITUTION:An automatic transmission which consists of the first to the third epicyclic gear mechanisms 1 to 3 achieves the speed change steps, forward 5 steps and the backward one step, by the selective engaging and releasing of clutches K1 to K5, and brakes B1 to B4. Here at, in, a control unit E, a specific speed change step is set in a engaging/releasing pattern using a small number of friction engaging means (K1-K5, and B1-B4) to be switched in operation in the case of speed change. And when the rotational frequency of a rotary member composing a gear train becomes to a specific standard value or more, in such a condition, the engaging/releasing pattern is changed to such a one in which the rotational frequency of the rotary member drops less than the standard value. In such a way, the change frequency of the engaging/releasing pattern is reduced, and the durability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an automatic transmission that performs gear changes by changing the engagement/disengagement state of a plurality of friction engagement means such as clutch means and brake means. The present invention relates to an automatic transmission that has a plurality of combination patterns of engagement and release of frictional engagement means for setting the gear stage.

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. To solve these problems, for example, Japanese Patent Laid-Open No. 60-57036 proposes an automatic transmission configured such that the gear ratio in reverse gear is close to the gear ratio in first forward gear. .

To briefly explain the configuration of the automatic transmission according to this proposal, it is mainly composed of three sets of single-binion type planetary gear mechanisms, including a sun gear of the first planetary gear mechanism and a second planetary gear mechanism. The sun gear of the first planetary gear mechanism is connected permanently or selectively, 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 are connected to each other, the carrier of the first planetary gear mechanism is 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 to the clutch. connected via. The input shaft is connected to a sun gear of the first planetary gear mechanism and a sun gear of the second planetary gear mechanism which are connected to each other via a clutch, and is connected to a ring gear of the first planetary gear mechanism via another clutch. It has become so. 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. This Japanese Patent Publication No. 60-57036
In the automatic transmission according to the above issue, in the first forward speed, the third
By engaging the brake for fixing the sun gear of the planetary gear mechanism and at the same time engaging the clutch that connects the carrier of the second planetary gear mechanism to the sun gear, the second planetary gear mechanism can be fixed.
The carrier of the planetary gear mechanism is prevented from rotating, and the carrier of the second planetary gear mechanism is similarly fixed in the reverse gear.

The gear ratios of the first forward gear and the reverse gear have similar values.

Problems to be Solved by the Invention In the conventional automatic transmission described above, the main gears are five forward gears and one reverse gear, and 2.5th gear and 3.5th gear are added to this, resulting in a total of 7 forward gears. Although it is possible to set one reverse gear, there is only one type of clutch and brake engagement/release combination to set each gear, and for this reason, the conventional automatic transmission described above is In the aircraft, there was a risk that the durability of the planetary gear mechanism that makes up the gear train would be impaired. In other words, in the conventional automatic transmission described above, there is only one combination pattern of engagement and release of the frictional engagement means to set each gear stage.
The rotation speed of one of the rotating members such as the sun gear of the planetary gear mechanism may increase at any gear stage, and in that case there is no particular means to lower the rotation speed.
Bearing wear may progress and durability may decrease.

In addition, in automatic transmissions using multiple sets of planetary gear mechanisms, by providing a clutch between rotating members such as sun gears in each planetary gear mechanism, the number of gears that can be set and the predetermined gears can be controlled. The number of combination patterns of engagement and release of the frictional engagement means to be set increases, and therefore, even in the automatic transmission described in the above-mentioned Japanese Patent Application Laid-open No. 60-57036, the rotating member of the planetary gear mechanism Since a clutch is disposed between the two, there may be a plurality of combination patterns of engagement and release of the clutch and brake to set any gear stage. However, even if this were the case, not only is there no mention of this in the above-mentioned publication, but there is also no description of a method for effectively utilizing the combination pattern of engagement and release of the clutch and brake.

The present invention has been made against the background of the above-mentioned circumstances, and it is an object of the present invention to effectively utilize engagement/disengagement patterns of a plurality of types of frictional engagement means in order to set a predetermined gear stage, thereby impairing shift controllability. It is an object of the present invention to provide an automatic transmission that can improve durability without causing problems.

Means for Solving the Problems 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, and An automatic transmission in which there are multiple types of combination patterns of engagement and release of frictional engagement means that set a predetermined gear stage, the gear ratio is the same, but the rotation speed of one of the rotating members in the gear train is different. In this method, the predetermined gear stage is set with an engagement/disengagement pattern of frictional engagement means with a small number of frictional engagement means whose engagement/disengagement state should be switched when shifting from another gear stage, and When the rotation speed of any of the rotating members in the engagement/release pattern is equal to or higher than a predetermined reference value, an engagement/release pattern in which the gear ratio is the same and the rotation speed of the rotating member is less than or equal to the reference value. It is characterized by comprising a control means for changing.

Function: The automatic transmission of the present invention has a plurality of engagement/disengagement patterns of the frictional engagement means for setting a predetermined gear stage, and furthermore, one of these patterns is different from the other patterns. In this case, even if the obtained speed change ratio is the same, the rotational speed of one of the rotating members in the gear train is different. In this invention, such a gear position is set in one of the engagement/disengagement patterns, but in the case of shifting from another gear position, the friction engagement means to be switched between the engagement and disengagement state is set when changing gears. If the number of rotations of any rotating member in that pattern is higher than a predetermined reference value, the pattern for setting the gear will be changed to a lower number of engagement/release patterns. The control means controls the rotation speed of the member to be changed to a pattern in which the rotation speed of the member is also less than or equal to the reference value. Therefore, in this invention, the rotational speed of the rotating member in the gear train is reduced, and the engagement/release pattern changes less frequently, so that the bearings, frictional engagement means, or the servo mechanism for operating the same are durable. Improves sex. Furthermore, since the speed change is performed in a pattern that reduces the number of frictional engagement means to be switched between engagement and disengagement, the speed change control is easy.

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 composed 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. The opening of the first step selectively connects the two.
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 brake means B1 for selectively preventing the 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. 5th gear, 2nd gear, and 7th gear are added, and the so-called 3.2nd gear and 3.5th gear are added between the 3rd and 4th forward gears, resulting in upper 0 forward gear and reverse gear. 1
In principle, it is possible to set the gears of 2nd, 2nd, 2.7th, 3.2nd, and 3rd and 5th gears.
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. Table 2 also shows the number of revolutions of the rotating members in each planetary gear mechanism 1.2.3 at each gear stage. In addition, in Table 1, ○
The mark indicates engagement, the blank indicates release,
In addition, the * mark indicates that it may be engaged, and furthermore, this * mark indicates that it may be engaged.
The marks indicate those that do not cause a change in the gear ratio or rotational state even if they are released, such as the fifth clutch means 5 in the first speed and the first brake means Bl, and those that do not cause a change in the gear ratio or rotational state when released, such as the fifth clutch means 5 in the first speed or the first brake means Bl in the pattern in column b in the fourth speed.
Brake means Bl, when released, does not change the gear ratio but changes the rotational state, and the fourth clutch means in the pattern of column b of 2nd speed is 4 or the third brake means B3.
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. In addition, in Tables 1 and 2, the columns marked with a, b, c, etc. for 2nd, 3rd, 4th, 5th, and reverse gears indicate the gears in question. Among the engagement/release patterns for the purpose of
The symbols ■, ■, . . . represent the types of engagement/disengagement patterns even though the rotational speeds of the rotating elements of the planetary gear mechanism do not differ. Furthermore, the values shown in Table 2 are for each planetary gear mechanism 1, 2.
．． 3 gear ratio (ratio of the number of teeth between the sun gear and the ring gear) is ρ1=0450, ρ2=0.405, ρ3=0.
405 and the input rotation speed is 1°.

(This page, blank space below) Table 1 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, the fourth clutch means 4 and the first brake means Bl are each connected to the one-way clutch 20.
．． 40, the fourth clutch means has a
If the relative rotation 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 is engaged, the one-way clutch is normally engaged. 20, the multi-disc clutch 22 is engaged when engine braking is required, and if the relative rotational direction of the two sun gears IS, 25 is in the direction in which the one-way clutch 20 is disengaged. , the multi-disc clutch 22 is engaged to bring the fourth clutch means 4 into an engaged state. The same applies to the first brake means Bl, and if the rotational direction of the sun gear 3S of the third planetary gear mechanism 3 is the direction in which the one-way clutch 40 is engaged, the one-way clutch 40 is engaged and the first When the brake means B1 is engaged and engine braking is required, the multi-plate brake 42 is engaged, and on the contrary, the third planetary gear mechanism 3 is engaged.
If the rotational direction of the sun gear 3S is the direction in which the one-way clutch 40 is released, the multi-disc brake 42 is engaged and the first
The brake means Bl is brought into engagement.

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. As a control means, a hydraulic control device C supplies and discharges hydraulic pressure to engage and release each of the clutch means and brake means, and input data such as vehicle speed V, throttle opening θ, or cooling water temperature. An electronic control unit (ECU) E is provided which outputs an electrical instruction signal to the hydraulic control device C based on.

In the automatic transmission shown in FIG. 1, when setting each gear, the engagement/disengagement pattern of the clutch means and brake means for setting each gear is also selected. The determination is made using the rotational speed of the rotating members constituting the gear train, ie, the sun gears of each planetary gear mechanism 1, 2, 3, as a criterion.

To explain more specifically, in the configuration shown in FIG. 1, the fifth forward speed can be set in the pattern in column a, the pattern in column b, and the pattern in column C, and the rotating member in each of these patterns can be set. As shown in Table 2, the rotational speeds of the two are greatly different.

When setting the fifth speed, if the previous state was the pattern ■ in column a of the fourth speed, as is known from Table 1, the fourth clutch means is released 7, and When the third brake means B3 is engaged or when the fourth clutch means 4 is in the engaged state by the engagement of the one-way clutch 20, the one-way The clutch 20 is automatically released, and as a result, the fifth speed is set according to the pattern in column b.

Alternatively, if a shift to the fifth speed is performed with the third speed set in the pattern in the column d, the pattern in the column b is selected as the pattern for setting the fifth speed, and an instruction signal is output. When the first braking means B1 is released and the third braking means B3 is engaged, or if the first braking means B1 is in the engaged state by the engagement of the one-way clutch 40, the third braking means B3 is engaged. The fifth speed is set by automatically releasing the one-way clutch 40 as the three-brake means B3 engages.

If the engagement/disengagement pattern is switched in this manner, the number of frictional engagement means to be switched to perform a shift operation is reduced to two, thereby facilitating shift control. On the other hand, the fifth
In the pattern in column b of speed, as is known from Table 2,
The rotation speed of the sun gear 3S of the third planetary gear mechanism 3 is approximately 2.40 times the input rotation speed, and when the input rotation speed is large, the rotation speed of the sun gear 3S becomes excessive. Therefore, in the automatic transmission shown in FIG. 1, the number of rotations of the rotating members forming the gear train is detected, and if the detected value is equal to or greater than a predetermined value α, the pattern is changed to a pattern in which the number of rotations decreases. In other words, if the 5th gear is set according to the b-column pattern, if the rotational speed of the sun gear 3S of the third planetary gear mechanism 3 becomes equal to or higher than the reference value α due to an increase in the input rotational speed, the 5th gear is changed to the first gear. The electronic control unit E outputs an instruction signal to set according to the pattern in column a in the table, and the accompanying hydraulic control device 1c
The engagement/disengagement pattern is changed depending on the output from.

On the contrary, if the input rotational speed is low, the rotational speed of the sun gear 3S will not exceed the reference value α, so the pattern for setting the fifth speed remains the pattern in column b.

The above control can be shown in a flowchart as shown in FIG. 2. In step 1, it is determined whether the fifth speed is set according to the pattern in column b, and if the determination result is "no",
The scanning process returns, and if the answer is "yes", the process proceeds to step 2, where it is determined whether the rotational speed Ne of the rotating member is greater than or equal to the reference value α. If the determination result is "no", the operation process returns and the fifth speed remains set according to the pattern in column b. On the other hand, if the determination result is "yes", the process proceeds to step 3, where the engagement/disengagement pattern is changed to set the fifth speed according to the pattern in column a.

Among the above-mentioned controls, the detection of the rotational speed of the rotating member may be performed by providing a sensor corresponding to each rotating member, but the relative rotational speed of each rotating member is determined by the gear train as shown in Table 2. Since it can be known in advance by the configuration, the rotation speed of the input shaft 4 may be detected and the value may be multiplied by the numerical values shown in Table 2 to obtain the rotation speed. Furthermore, since it is possible to know in advance which rotating member has a high rotational speed, only the rotational speed of that rotating member may be detected. Furthermore, in order to ensure the stability of the behavior of each rotating member and prevent the occurrence of abnormal shocks or noise, change the engagement/disengagement pattern only after the gear has been shifted to the relevant gear. Therefore, the engagement/disengagement pattern is changed after confirming that the speed change is completed by detecting the rotation speed of a predetermined rotating member such as the rotation speed of the output shaft 5, or after a preset time has elapsed using a timer. It is preferable to control the execution after confirming the following.

The above-mentioned change in the engagement/disengagement pattern can be executed in a gear where there are multiple types of patterns for setting the gear, and the pattern selected and set at the time of shifting is The number of frictional engagement means that must be switched between the engaged and disengaged states is reduced, and the engagement/disengagement pattern is changed when the rotational speed of any rotating member in that pattern exceeds the reference value α. will be carried out.

The control is performed by the electronic control unit E and the hydraulic control device C.

Therefore, in the automatic transmission shown in FIG. 1, the engagement/disengagement pattern of the frictional engagement means for setting a predetermined gear is changed when the rotational speed of any rotating member increases. Since the frequency of this does not become particularly high, the durability of the frictional engagement means is improved, and since the abnormal increase in the rotational speed of the member is also prevented, the durability of the bearing etc. is also improved. Furthermore, since the number of frictional engagement means to be switched between engaged and disengaged states during gear shifting can be kept to a small number, gear shifting controllability can be maintained favorably.

Note that the present invention can be applied to automatic transmissions other than the configuration shown in FIG. 1, and an example thereof is shown in FIG. 3. The configuration shown in FIG. 3 is a modification of the configuration shown in FIG. 1 described above, in which the connections between the rotating members constituting the gear train are partially changed. That is, first to third planetary gear mechanisms 1, 2.3, which are single pinion type planetary gear mechanisms, are arranged on the same axis between the input shaft 4 and the output shaft 5, which are arranged on the same axis. ring gear 2 of the second planetary gear mechanism 2
R and the ring gear 3R of the third planetary gear mechanism 3 are connected, and the carrier IC of the first planetary gear mechanism I is connected to these ring gears 2R and 3R. The clutch means includes a first clutch means Kl that connects the input shaft 4 and the ring gear IR of the first planetary gear mechanism 1, a sun gear 13 of the first planetary gear mechanism 1, and a second planetary gear mechanism 2.
2 to the second clutch means connecting the carrier 2C of the first planetary gear mechanism 1, 3 to the third clutch means connecting the input shaft 4 and the ring gear IR of the first planetary gear mechanism 1, and 3 to the third clutch means connecting the input shaft 4 and the ring gear IR of the first planetary gear mechanism 1; 4 is attached to a fourth clutch means that connects the sun gear 2S of the planetary gear mechanism 2, and 5 is attached to a fifth clutch means that connects the carrier 2c of the second planetary gear mechanism 2 with the sun gear 3S of the third planetary gear mechanism 3, respectively. It is provided. The brake means include a first brake means Bl that fixes the sun gear 3S of the third planetary gear mechanism 3, a second brake means B2 that fixes the carrier 2c of the second planetary gear mechanism 2, and a sun gear of the second planetary gear mechanism 2. 2S, the third brake means B3, and the sun gear I of the first planetary gear mechanism 1.
A fourth brake means B4 for fixing S is provided respectively. The output shaft 5 is connected to the carrier 3c of the third planetary gear mechanism 3.

Even with the automatic transmission having the configuration shown in FIG. 3, it is theoretically possible to set 10 forward gears and 1 reverse gear.
The operation table is shown in Table 3, and the number of rotations of each rotating member (
The number of revolutions when the number of revolutions of the input shaft 4 is taken as "engine") is the fourth
Shown in the table. In addition, the gear ratio of each planetary gear mechanism 1.2.3 is ρl=0.4501ρ2=0.569, ρ3=0
．． It is 405.

(This page, the following margins) Table 1 As is clear from these tables, in the configuration shown in Figure 3, multiple types of engagement with different rotational speeds of rotating members are possible in the second forward speed and the third forward speed. - There is a release pattern, so for example, if the rotation speed of the sun gear 2S of the second planetary gear mechanism 2 increases above the reference value while the second speed is set in the pattern in column a, the pattern will be changed to the pattern in column b. , or the third
If the rotational speed of the sun gear 2S of the second planetary gear mechanism 2 increases above the reference value with the speed set in the pattern in column a, the pattern is changed to the bs pattern. Such control is performed by a hydraulic control device and an electronic control unit (not shown).

By the way, in FIG. 3, each friction engagement means is shown as a symbol of a multi-plate structure, but similarly to the configuration shown in FIG. It can be done.

Furthermore, although each of the above-mentioned embodiments is an example in which a gear train is constructed using three sets of single pinion type planetary gear mechanisms, the present invention is also applicable to an automatic transmission in which a gear train is constructed using a double pinion type planetary gear mechanism. For example, Japanese Patent Application No. 1-185151, Japanese Patent Application No. 1185152, Japanese Patent Application No. 1-186991, Japanese Patent Application No. 1-186992, Japanese Patent Application No. -205478
The present invention is applicable to automatic transmissions that have multiple types of engagement/disengagement patterns for setting one of the gears, as shown in the specifications and drawings of Japanese Patent Application No. 1-280957. Can be applied.

Effects of the Invention As is clear from the above explanation, in the automatic transmission of the present invention, a predetermined gear stage is set by an engagement/disengagement pattern with less frictional engagement means to be operated during gear shifting, and in that state. This is because it has control means for changing the engagement/disengagement pattern so that the rotational speed of the rotating member becomes less than or equal to the reference value when the rotational speed of the rotating member constituting the gear train exceeds a predetermined reference value. , the frequency of changing the engagement/disengagement pattern for setting the gear stage is reduced, and as a result, the durability of the frictional engagement means can be improved, and the rotational speed of the rotating members constituting the gear train can also be reduced. Since the increase does not exceed the above, durability can be improved in this respect as well.Furthermore, when changing gears, a pattern is selected in which the number of frictional engagement means to be switched between engagement and disengagement states is reduced. Shift controllability is good.

[Brief explanation of drawings]

Figure 1 is a skeleton diagram showing one embodiment of this invention, Figure 2 is a skeleton diagram showing an embodiment of the present invention.
The figure is a flowchart of engagement/disengagement pattern change control.
FIG. 3 is a skeleton diagram showing a gear train according to another embodiment of the present invention. 1.2.3...Planetary gear mechanism, 13.2S, 3S・
・Sun gear, IC, 2C, 3C...carrier, I
R, 2R, 3R...Ring gear, 4...Input shaft,
5... Output shaft, C... Hydraulic control device, E...
Electronic control unit.

Claims (1)

[Scope of Claims] A gear train having a plurality of frictional engagement means and a gear train set to a plurality of gears having different gear ratios depending on the engagement/disengagement state of these frictional engagement means, In automatic transmissions in which there are multiple types of combination patterns of engagement and release of friction engagement means that set the gear stage, the gear ratio is the same but the rotation speed of one of the rotating members in the gear train is different. , the predetermined gear stage is set with an engagement/disengagement pattern of frictional engagement means that has a small number of frictional engagement means whose engagement/disengagement state should be switched when shifting from another gear stage; If the rotation speed of any of the rotating members in the engagement/disengagement pattern exceeds a predetermined reference value, change to an engagement/release pattern in which the gear ratio is the same and the rotation speed of the rotating member is below the reference value. An automatic transmission for a vehicle, comprising a control means for controlling the transmission.