JP2822538B2 - 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 used for a vehicle such as an automobile, and more particularly, to an automatic transmission configured to set a plurality of shift speeds by frictional engagement means such as a clutch or a brake. It is about.

2. Description of the Related Art Automatic transmissions mounted on vehicles such as automobiles have characteristics such as small size and light weight, easy control for shifting, and low shift shock. It is desired to be able to set a large number of gear stages of the gear ratio. In order to increase the number of shift stages that can be set, the number of planetary gear mechanisms constituting the gear train is increased, or the number of frictional engagement means such as clutches and brakes is increased to constitute the gear train. What is necessary is just to comprise so that the connection relationship and fixed state of a rotating element may be changed variously. As an example, the present applicant has constituted a gear train mainly composed of three sets of planetary gear mechanisms, and has a main shift between the first to fifth forward speeds to the fifth speed and the reverse speed in which the speed ratio is close to a geometric series. An automatic transmission has already been proposed that can set an intermediate stage between the second and third speeds and an intermediate stage between the third and fourth speeds. In the automatic transmission, since the connection relationship and the fixed state of the elements of the planetary gear mechanism constituting the gear train can be changed in various ways, the number of shift stages that can be set is increased, There are a plurality of types of combinations of engagement / disengagement of the frictional engagement means (i.e., engagement / release patterns) for setting. The engagement / disengagement patterns include those in which the rotation speed of the rotating member does not change, and those in which the rotation speed of any of the rotation members changes, and therefore, the friction engagement means for setting a predetermined gear position. Depending on the selection method, the shift shock, the shift controllability, and the durability of the friction engagement means are greatly affected. Therefore, the present applicant is a shift control method for an automatic transmission in which a plurality of engagement / disengagement patterns can be selected in order to set a predetermined gear position. A gear shift control method for changing the gear ratio to another engagement / disengagement pattern prior to gear shifting so as to reduce the variable rotation speed of the rotating member due to gear shifting has already been proposed by Japanese Patent Application No. 1-280953. .

Problems to be Solved by the Invention Shifting in an automatic transmission causes a change in the number of rotations of a rotating member constituting a gear train at the same time as a change in the ratio of the number of rotations between an input shaft and an output shaft. -For a shift speed having a plurality of types of release patterns, the rotational speed of the rotating member may be different for each engagement / disengagement pattern. The engagement / disengagement pattern is to be changed in advance so that the number is reduced as much as possible. However, in an automatic transmission, a plurality of shift speeds used in normal traveling are not always used, and a shift to a specific shift speed may be prohibited. If the release pattern is changed, unnecessary shift control will be performed. That is, the automatic transmission basically shifts based on the engine load represented by the throttle opening and the vehicle speed. For example, when traveling uphill, a high torque is required even at a certain high vehicle speed. When the shift lever is set to the L range, for example, the gear is not shifted to a specific gear or higher by manual operation, and when the engine temperature is low and sufficient torque is not generated, Upshift to a predetermined gear or higher is prohibited by an output signal from the controller,
Further, the shift to the overdrive stage may be prohibited by an occupant's button operation. In such a case, if the engagement / disengagement pattern is changed in such a manner that the shift to the prohibited gear is to be performed, the shift must be re-engaged before the shift to another non-prohibited gear. It is necessary to change the combination / release pattern, so that not only the first change control is wasted, but also a new change control has to be performed. When such unnecessary change control is performed, wear occurs due to slippage of the frictional engagement means each time, so that the durability of the frictional engagement means is reduced, and problems such as a delay in shifting are caused.

The present invention has been made in view of the above circumstances,
An object of the present invention is to improve the durability of the engagement means by avoiding unnecessary change of the engagement / release pattern.

Means for Solving the Problems According to the present invention, in order to achieve the above object, a plurality of engagement means and a plurality of shift speeds are set according to a state of engagement / disengagement of these engagement means, And a gear train having a plurality of types of engagement / disengagement combination patterns of engagement means for setting a predetermined shift speed among those shift speeds, further comprising: shifting from the predetermined shift speed to another shift speed. In the automatic transmission for a vehicle in which shifting of the predetermined speed is selectively prohibited, the pattern of the combination of engagement and release of the engagement means is set to the predetermined speed while the predetermined speed is set. Control for preliminary change in preparation for shifting from the first gear position and the engagement and engagement while the predetermined gear position is set when shifting from the predetermined gear position to another gear position is prohibited. A system for prohibiting the preliminary change of the release combination pattern And a control device for performing the control.

The gear train in the automatic transmission according to the present invention has a plurality of types of engagement / disengagement combination patterns of the engagement means for setting a predetermined shift speed. The release pattern can be preliminarily changed.
If the shift to a specific gear is prohibited, such as prohibiting the setting of the overdrive gear or limiting the gear to a gear only during a predetermined low gear, the control device issues a command to the prohibited gear. Preliminary change of the engagement / disengagement pattern to be performed in anticipation of a shift is prohibited. As a result, unnecessary switching of the engagement means is prevented.

Embodiment Next, an embodiment of the present invention will be described 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 third 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.

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 shaft 4 and the sun gear 1S.

In practical use, each of the above clutch means K1,
~ K4 can be configured as a multi-plate clutch, a one-way clutch or a combination thereof, and there are restrictions on the arrangement of each component, so a connecting drum or the like as a connecting member for each clutch means K1, ~ K4 It goes without saying that an appropriate intermediate member can be interposed.

The second planetary gear mechanism 2 serves as brake means for preventing the rotation of the rotating members in the planetary gear mechanisms 1, 2, and 3 described above.
Brake means B2 disposed between the carrier 2C of the vehicle and a transmission case (hereinafter simply referred to as a case) 6
And a third brake means B3 disposed between the sun gear 2S of the second planetary gear mechanism 2 and the case 6. As these brake means B2, B3, a multi-plate brake, a band brake, or a configuration in which these are combined with a one-way clutch can be adopted.These brake means B2, B3 and their brake means B2, B3, Needless to say, an appropriate connecting member can be interposed between the member to be fixed by B3 and 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 connected to each other. ing.

Also in the automatic transmission having the configuration shown in FIG. 1, the clutch means K1 to K4 and the brake means B2, B3 are appropriately engaged and
A plurality of shift speeds can be set by releasing the gear, and a hydraulic control device C and an electronic control unit (ECU) E are provided as control devices for performing the control. The electronic control unit E calculates a gear to be set based on input data such as a vehicle speed V, a throttle opening θ, a traveling mode select signal, and a coolant temperature, and outputs a signal to the hydraulic control device C. A conventional configuration mainly including a microcomputer can be employed. The hydraulic pressure control device C supplies and discharges hydraulic pressure for engaging and disengaging the clutch means and the brake means. The hydraulic pressure control device C operates the pressure regulating valve, the shift control valve, and the shift control valve. Conventionally known devices having the above-mentioned solenoid valve and the like can be adopted.

The shift speed set based on the output of the above-described control device is obtained by adding 2.5 speeds, 3.2 speeds, and 3.5 speeds to the five main forward speeds and the reverse speed, which have a relationship where the gear ratio is close to a geometric series. Table 8 shows the operation table for setting these eight forward speeds and one reverse speed. In Table 1, ○ indicates engagement, blank indicates release, and * indicates that engagement may be performed.
The columns with the symbols... Indicate different engagement / disengagement patterns for setting the gear.

As is clear from Table 1, in the automatic transmission having the configuration shown in FIG. 1, there are a plurality of types of engagement / disengagement patterns for setting the fourth speed. When this fourth speed is set, shifting is prohibited. The engagement / disengagement pattern is selected based on the presence or absence of the condition.

FIG. 2 is a flowchart showing an example of a control routine for the control. The example shown here is an example in which the ON / OFF state of the overdrive selection switch is set to the presence or absence of a prohibition condition. That is, first, in step 1, it is determined whether or not the drive range (D range) is selected by a shift lever (not shown). If the determination result is “no”, the present control ends, and if “yes”, the control ends. For example, the process proceeds to step 2 to determine whether or not there is a shift instruction from the third speed to the fourth speed. If the result of the determination is "no", this control ends. If the result of the determination is "yes", the routine proceeds to step 3, where the fourth speed is set by the engagement / release pattern (4th-pattern) in Table 1. Perform output. This 4th- pattern is the first
Or an engagement / disengagement pattern for engaging the third clutch means K1, K2, K3, and the third speed corresponds to the first clutch means K1, the third
Since the clutch means K3 and the second brake means B2 are set to be engaged, when shifting from the third speed to the fourth speed, the second brake means B2 is released and the second clutch means K2 is engaged. Thus, the number of the friction engagement means to be switched is two, so that the shift can be performed without deteriorating the shift shock. Then, in step 4, it is determined whether or not the overdrive switch (0 / D SW) is on. If the determination result is "yes",
Proceeding to step 5, the throttle opening θ is set to the predetermined reference value α.
A determination is made whether it is greater than. If the determination result is "NO", an output is made to change the engagement / disengagement pattern for setting the fourth speed from the pattern shown in Table 1 to the pattern shown in Table 1 (step 6). That is, in the fourth speed state, if the throttle opening θ is small, there is a high possibility that a shift to the fifth speed will occur, and in the fifth speed, as shown in Table 1, the second clutch means K2 and the third clutch Since the means K3 and the third brake means B3 are set to be engaged, the fourth shift is performed so as not to achieve a so-called simultaneous shift when switching to this engagement / release pattern.
The speed is preliminarily changed so as to be set in a pattern, that is, by engaging the second to fourth clutch means K2, K3, K4.

On the other hand, if the result of the determination in step 4 is “NO”, it means that setting the fifth speed is prohibited,
In step 7, control is performed to prohibit the preliminary change of the engagement / disengagement pattern for setting the fourth speed to the pattern shown in Table 1, and thereafter this control is terminated.
If the result of the determination in step 5 is "yes", the accelerator pedal is depressed in the fourth speed state, and there is a low possibility that an upshift to the fifth speed will occur. As in step 7, control is executed to prohibit the preliminary change of the engagement / disengagement pattern for setting the fourth speed to the pattern shown in Table 1, and thereafter this control is terminated.

Therefore, in the automatic transmission shown in FIG. 1 that performs the above control, when the overdrive switch is turned on and the shift to the fifth speed is permitted, the automatic transmission changes to the 4th-pattern in which the shift to the fifth speed is scheduled. However, when the shift to the fifth speed is prohibited, such a change in the engagement / disengagement pattern does not occur, so that useless switching is prevented and the frictional engagement means is prevented. The durability of is maintained well,
Since the downshift from the fourth speed to the third speed is performed from the 4th-engagement / release pattern, the engagement / release
It is unnecessary to change the release pattern, so that it is possible to prevent a delay in shifting to the third speed. The present invention is not limited to the above embodiment. For example, FIG. It can also be applied to the automatic transmission shown. That is, FIG. 3 is a skeleton diagram showing a gear train according to another embodiment of the present invention. In the gear train shown in FIG. 3, the fourth clutch means K4 in the configuration shown in FIG. It is composed of a one-way clutch 20 and a multi-plate clutch 22, and a carrier 2C of the second planetary gear mechanism 2.
Fifth clutch means K5 for selectively connecting the sun gear 3S and the sun gear 3S of the third planetary gear mechanism 3 is provided.
As the first brake means B1 for selectively fixing the sun gear 3S of the planetary gear mechanism 3, a brake means comprising a one-way clutch 40 and a band brake 42 which are in parallel with each other is provided, and further, the second brake means B2 is provided. A one-way clutch 60 and a multi-plate brake 61 which are in a parallel relationship with each other, and the third brake means B3 is a band brake,
Other configurations are the same as those shown in FIG.
Table 2 shows the shift speeds that can be set in the automatic transmission shown in FIG. 3 and the engagement / disengagement patterns for setting the respective shift speeds. In Table 2, ◎ indicates that the vehicle is engaged during engine braking.

As can be seen from Table 2, the automatic transmission having the gear train shown in FIG. 3 can make a preliminary change in the engagement / disengagement pattern intended for shifting from the fourth speed to the fifth speed. However, when the fifth speed is prohibited, such as when the overdrive switch is turned off, the state of the fourth speed is set in the pattern of Table 2 and the preliminary change to the pattern is prohibited. In the third speed, there are also two types of engagement / disengagement patterns, and a preliminary change of the engagement / disengagement pattern is made in preparation for shifting to the fourth speed, but when the fourth speed is prohibited, Sets the third speed in the pattern shown in Table 2 and prohibits a preliminary change to the third pattern. By performing such control, useless switching of the friction engagement means is prevented as in the embodiment shown in FIG.

FIG. 4 is a skeleton diagram showing a gear train according to a third embodiment of the present invention. The gear train shown here is the same as the gear train shown in FIG. 1 except that the ring gear 2R of the second planetary gear mechanism 2 is the same as the gear train shown in FIG. The carrier 3C of the second planetary gear mechanism 2 is connected to the ring gear 3R instead of the carrier 3C of the third planetary gear mechanism 3, and
A fifth clutch means K5 for selectively connecting the sun gear 3S of the third planetary gear mechanism 3 and a first brake means B1 for selectively fixing the sun gear 3S of the third planetary gear mechanism 3;
Other configurations are the same as those shown in FIG.
In the automatic transmission having the gear train shown in FIG. 4, the gears shown in Table 3 and the engagement gears for setting the respective gears are set.
A release pattern is possible, and therefore, for a shift speed having a plurality of types of engagement / disengagement patterns, a variable rotation speed of the rotating member is reduced when shifting to another shift speed while setting the shift speed. The engagement / disengagement pattern is preliminarily changed as necessary so that the gears are not shifted simultaneously. When the shift to a predetermined shift speed such as the fifth speed is prohibited, the control device prohibits the preliminary change of the engagement / disengagement pattern that is scheduled to shift to the prohibited shift speed, and as a result, Useless switching of the friction engagement means is prevented. Such control may be performed, for example, according to the flowchart shown in FIG.

In the above description, an upshift to an adjacent shift speed among the main shift speeds is taken as an example. However, the present invention is not limited to the above-described embodiment, and other shift speeds separated by two or more shift speeds are used. When performing a so-called jump shift, a preliminary change of the engagement / disengagement pattern prepared for the shift and a preliminary change of the engagement / release pattern based on a predetermined prohibition condition may be prohibited. Also, not limited to prohibition at the time of upshift, for example, when setting of a predetermined low gear is prohibited due to some failure,
Preliminary change of the engagement / disengagement pattern in preparation for the downshift to the prohibited shift speed may be prohibited. The prohibition conditions in the present invention include, besides the turning off of the overdrive switch shown in the above embodiment, that the engine temperature (cooling water temperature) is low, and the range selected by operating the shift lever is the L range. And so on. Further, the automatic transmission to which the present invention can be applied may be other than the one having the gear train shown in FIG. 1, FIG. 3, or FIG. Any number of combinations of engagement / disengagement patterns may be used. For example, Japanese Patent Application Nos. 1-185151 and 1-18 already proposed by the present applicant.
No. 5152, Japanese Patent Application No. 1-1869991, Japanese Patent Application No. 1-186992, Japanese Patent Application No. 1-205478, Japanese Patent Application No. 1-280957, etc. The present invention can be applied to a transmission.

Effect of the Invention As described above, in the automatic transmission according to the present invention, since the shift to a predetermined shift speed is prohibited, a preliminary engagement / disengagement pattern for setting the shift speed is set. Since the configuration is such that the change is prohibited, useless switching of the engagement / disengagement pattern while setting the gear position is prevented,
As a result, it is possible to improve the durability of the engagement means and to prevent a delay in shifting.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing an embodiment of the present invention in principle, FIG. 2 is a flowchart showing an example of a control routine, and FIGS. 3 and 4 each show a gear train in another embodiment of the present invention. FIG. 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.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 59/10-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (1)

(57) [Claims] A plurality of gears are set according to a state of engagement and disengagement of the plurality of engagement means, and a predetermined one of the gears is set. And a gear train having a plurality of types of combination patterns of engagement / disengagement of the engagement means for the automatic transmission for a vehicle, wherein a shift from the predetermined gear to another gear is selectively prohibited. The pattern of the combination of engagement and disengagement of the engagement means for setting the predetermined speed is preliminarily changed in preparation for a shift from the predetermined speed while the predetermined speed is being set. When the control and the shift from the predetermined gear to another gear are prohibited, the preliminary change of the combination pattern of the engagement and disengagement while the predetermined gear is set is prohibited. And a control device for performing the control. Automatic transmission for vehicles.