JP2800358B2 - Control device for automatic transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift in an automatic transmission that can be set to a plurality of shift speeds in accordance with a combination of engagement and release of engagement means such as a clutch and a brake. In particular, the present invention relates to a control device for controlling a shift in an automatic transmission having a plurality of types of combinations of engagement and disengagement for setting any one of the shift speeds.

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 speed between the second speed and the third speed and an intermediate speed between the third speed and the fourth speed. 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 combinations of engagement / disengagement patterns (ie, engagement / release patterns) of the friction engagement means for setting the frictional engagement means. 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. Japanese Patent Application No. 1-280952 has already proposed a method of performing a shift by selecting an engagement / disengagement pattern so that the rotational speed of a rotating member accompanying a shift is equal to or less than a predetermined value.

Problems to be Solved by the Invention In general, a shift in an automatic transmission is performed by supplying hydraulic pressure to one of engagement means to engage the same, or simultaneously discharging the pressure from another engagement means to reduce the engagement. This is done by releasing the engine.However, the rotational speed of the rotating member including the engine is different before and after the shift, so that the supply hydraulic pressure rises to some extent slowly so that the inertia energy accompanying the rotational fluctuation is absorbed by the engagement means. It has been adjusted to be. Such oil pressure adjustment is generally performed by an accumulator or by changing the characteristics of the accumulator by controlling its back pressure. In the above-described method, the control is performed so that the rotation fluctuation of the rotating member at the time of shifting is reduced, since it is advantageous in reducing the shock.

On the other hand, factors affecting the hydraulic pressure supplied to the engagement means are not limited to the accumulator and its back pressure,
The centrifugal force also affects the hydraulic pressure, and the degree increases as the number of rotations increases and as the radius increases.

However, in the method of Japanese Patent Application No. 1-280952 described above, since the engagement / disengagement pattern of the engagement means is selected by focusing only on the fluctuating rotation speed of the rotating member accompanying the speed change, the large diameter clutch is engaged. In some cases, an engagement / disengagement pattern that achieves shifting is selected. In such a case, the centrifugal force has a great effect on the timing of engagement of the clutch, and as a result, there is a possibility that the shift shock may be deteriorated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control device for an automatic transmission that can reduce the influence of centrifugal hydraulic pressure and reduce shift shock.

Means for Solving the Problems In order to achieve the above object, the present invention provides a plurality of engagement means including a clutch, and a plurality of shift speeds depending on the engagement / disengagement state of these engagement means. And a gear train configured to have a plurality of engagement / disengagement combination patterns of the engagement means for setting any one of these shift speeds. A gear position determining means for determining a gear position to be set based on running conditions; and a plurality of types of combination patterns of engagement / disengagement of the plurality of engaging means. A gear position setting unit that outputs a combined engagement / disengagement pattern that will achieve a gear shift by engaging a small-diameter clutch among the combined engagement / disengagement patterns in a certain gear stage. Have It is characterized by the following.

In the present invention, the gear to be set is determined by the gear determining means based on the running conditions. Further, the control device of the present invention is directed to an automatic transmission having a plurality of types of engagement / disengagement combination patterns (engagement / release patterns) of engagement means for setting any one of the gear positions,
The shift determining means determines whether the shift speed determined based on the traveling conditions is a shift speed that can be set by a plurality of types of engagement / disengagement patterns. If the determined gear position is a gear position that can be set by a plurality of types of engagement / disengagement patterns, the gear position setting section sets the engagement / release pattern.
Engage the small diameter clutch in the release pattern.
Output the release pattern. As a result, since the hydraulic pressure for engaging the clutch has a small radius, the effect of the centrifugal force is reduced, and the timing of the engagement of the clutch is adjusted accordingly, so that the shift shock is improved.

Embodiments Next, the present invention will be described based on embodiments.

FIG. 1 is a block diagram showing an example of a basic configuration of the present invention. An automatic transmission A mainly includes a plurality of sets of planetary gear mechanisms to be described later. A gear train configured to set a plurality of gears is provided. In addition, a hydraulic control device 10 that supplies or discharges hydraulic pressure to each friction engagement means in order to set each shift speed is provided, and as the hydraulic control device 10,
It is possible to use those having a configuration employed in a conventional general automatic transmission including a hydraulic pump, a pressure regulating valve, a shift valve, a solenoid valve, and the like. The hydraulic control device 10 is connected to an electronic control unit 11 that outputs a signal to set each shift speed. The electronic control unit 11 includes a shift speed determining unit 12, a shift speed determining unit 13, and a shift speed determining unit 13. A step setting unit 14 is provided. The gear position determination unit 12 determines a gear position to be set based on running conditions. More specifically, the gear position determination unit 12 correlates a gear position with an engine load such as a throttle opening and an output torque of an engine (not shown). The shift speed is determined in accordance with a shift diagram using the related signal θ and the signal V such as the output shaft rotation speed that is correlated to the vehicle speed as a parameter. There is no difference from the machine. Also, gear position determination unit
Reference numeral 13 is for determining whether or not the gear position determined by the gear position determining unit 12 is a gear position that can be set by a plurality of engagement / disengagement patterns. Further, the gear position setting section 14 outputs an engagement / disengagement pattern of the engagement means for setting the determined gear position. For a shift speed having a release pattern, a small-diameter clutch is engaged. The details will be described later.

FIG. 2 shows a row of gear trains in the automatic transmission A targeted by the above-described control device. The example shown here is mainly composed of three sets of single pinion type planetary gear mechanisms 1, 23, and the components of the planetary gear mechanisms 1, 2, 3 are connected as follows. 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 The third carrier 3C is 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 1S of the second planetary gear mechanism 2 is connected via the fourth clutch means K4. 2S, and the carrier 2C of the second planetary gear mechanism 2 is connected to the third carrier via the fifth clutch means K5.
It is connected to the sun gear 3S of the planetary gear mechanism 3.

In addition, as a connection mechanism of the above-mentioned respective elements, 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. As shown in the drawing, the multi-plate clutch as the second clutch means K2 has a smaller diameter than the multi-plate clutch 22 in the fourth clutch means K4 and is disposed radially inward. 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.

A first brake means B1 for selectively blocking the rotation of the sun gear 3S of the third planetary gear mechanism 3 as a brake means for preventing the rotating members of the planetary gear mechanisms 1, 2, and 3 from being rotated.
A second brake means B2 for selectively preventing rotation of the carrier 2C of the second planetary gear mechanism 2, and a third brake means for selectively preventing rotation of the sun gear 2S of the second planetary gear mechanism 2.
B3 is provided. Among these brake means, the first brake means B1 is 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 one-way clutch 40 and a band brake 42 in a parallel relationship with the one-way clutch 40. B2 is second
The one-way clutch 60 provided between the carrier 2C of the planetary gear mechanism 2 and the case 6 or an integral part thereof and a multi-plate brake 61 arranged in a parallel relationship with the one-way clutch 60. The third brake means B3 is constituted by a band brake. In practical use, an appropriate connecting member may be interposed between the brake means B1, B2, B3 and each element to be fixed by the brake means B1, B2, B3 or the case 6. Of course.

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 2.5th, 2.7th, 3.2th and 3.5th speeds, a combination of engagement and disengagement of clutch means and brake means (so-called engagement and
There are a plurality of sets of release patterns, which are shown in Table 1 as an operation table. 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. Five clutch means K5 and first brake means B1
The gear ratio and the rotation state do not change even when released, as in the case of releasing the first brake means B1 in the pattern of the fourth speed column b, but the gear ratio does not change but the rotation state changes. However, if the other * means such as the fourth clutch means K4 and the third brake means B3 in the pattern of the column b of the second speed are engaged, the gear ratio and the rotation state change even if released. Including those that do not occur. In Table 1, the second, third, fourth, fifth, and reverse gears
The columns marked with a, b, c, etc. indicate that the engagement / release patterns for setting the gear stage have different rotation speeds of the rotating elements of the planetary gear mechanism. ,... Represent the types of engagement / disengagement patterns, although the rotation speeds of the rotating elements of the planetary gear mechanism are not different.

In the control device for the automatic transmission A provided with the gear train shown in FIG. 2, the gear position determination unit 12 determines in the first table based on the signal θ related to the engine load and the signal V related to the vehicle speed. One of the gear positions shown is determined. In this case, the first gear, the second gear, the third gear, the fourth gear, and the fifth gear, which are the main gears, are set.
One of the speeds may be selected and determined, and an intermediate speed intermediate to the main speed, such as the second speed, may not be selected. In addition, the method of determining the speed may be related to the engine load. A shift diagram in which a shift point is determined using the signal θ and the signal V related to the vehicle speed as parameters is stored as data, and a method of determining a shift speed according to the shift diagram can be adopted. The speed determined by the speed determiner 12 is input to the speed determiner 13 to determine whether the speed is a speed that can be set by a plurality of types of engagement / disengagement patterns. In this case, if it is determined in advance that one of the above-mentioned main gears is set, all of the determined gears can be set with a plurality of types of engagement / disengagement patterns. When the result of the determination made by the gear position determining unit 13 is input to the gear position setting unit 14, the gear position determining unit 14 selects the smaller diameter from among the plurality of engagement / disengagement patterns for setting the determined gear position. An engagement / disengagement pattern for engaging the clutch is output. Specifically, in the gear train shown in FIG. 2, the gears that can be set by engaging either of the two clutch means are, as known from Table 1, the second gear and the fourth gear. It is fast. Therefore, when it is determined to set the second speed based on the running conditions, the second clutch means K2 and the fourth clutch means K4 that can be engaged in setting the second speed.
Of these, the second clutch means K2 is on the inside with a small diameter,
The gear position setting unit 14 outputs one of the engagement / disengagement patterns in the column a for engaging the second clutch means K2 among the engagement / disengagement patterns in the columns a and b of the second speed.
As for the fourth speed, at least the first clutch means K1 and the third clutch means K3
When setting at the 4th speed, select either the engagement / disengagement pattern or the engagement / disengagement pattern in column a in order to facilitate shifting control. However, since the engagement / disengagement pattern of the second clutch means K2 and the fourth clutch means K4 is an engagement / disengagement pattern for engaging the small-diameter second clutch means K2, the gear position determination unit 14 Outputs the engagement / disengagement pattern in the column a to set the fourth speed. The first
For other shift speeds such as speed, a predetermined engagement / disengagement pattern is output so that the shift control is easy and the shift controllability is good, such as with small fluctuations in rotation.

FIG. 3 is a flowchart showing a control routine for shifting to the second and fourth speeds. First, in step 1, various data such as a signal θ related to the engine load and a signal V related to the vehicle speed are shown. Is read, and the gear position determining unit 12 determines a gear position to be set based on the traveling conditions represented by the data (step 2).
Next, a determination is made on the determined gear position,
If it is the fourth speed (Yes in step 3), the engagement / disengagement pattern (4-a-
) Is output (Step 1), and if it is the second speed (No in Step 3 and Yes in Step 5), the engagement / disengagement pattern (2- a-) is output (step 6).

As described above, the predetermined engagement /
When the release pattern is output, the hydraulic control device 10
A hydraulic pressure is supplied to predetermined engagement means so as to achieve the engagement / release pattern so that the rollers are engaged, and the pressure is released from other engagement means and released.

Therefore, the above-described control device performs the shift by engaging the small-diameter clutch, so that the influence of the centrifugal force on the hydraulic pressure for engaging the clutch is small, and as a result, the hydraulic pressure is appropriately controlled, so that the shift shock is generated. Is reduced.

In the above description, since the automatic transmission having the gear train shown in FIG. 2 is targeted, the engagement / disengagement pattern for engaging the second clutch means K2 at the second speed and the fourth speed is described. However, the gears that can be achieved by engaging the clutches and the clutches that can be made smaller in diameter are various depending on the configuration of the gear train. The engagement / release pattern may be selected.

The present invention also relates to an automatic transmission capable of setting a predetermined gear position with a plurality of engagement / disengagement patterns, and in which different clutches can be engaged with the engagement / release patterns. The present invention can be applied to an automatic transmission including a mating / release pattern. Examples of this type of automatic transmission include Japanese Patent Application Nos. 1-185151 and 1-185151 which have already been proposed by the present applicant. No. 1-185152,
Japanese Patent Application No. 1-1869991, Japanese Patent Application No. 1-1869992, Japanese Patent Application No.
No. 205478, Japanese Patent Application No. 1-280957, etc., and the respective structures described in the drawings.

Effect of the Invention As described above, according to the present invention, the shift is achieved by engaging the small-diameter clutch which is less affected by the centrifugal force, so that the hydraulic pressure for the clutch to be engaged is appropriately controlled. As a result, shift shock can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention, FIG. 2 is a skeleton diagram showing an example of a gear train in the automatic transmission, and FIG. 3 is a flowchart showing a control routine. 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, 10 Hydraulic control device, 11 Electronic control unit, 12 Gear position determination unit, 13: gear position determination unit, 14: gear position setting unit, A: automatic transmission.

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Claims (1)

(57) [Claims] A plurality of engagement means including a clutch, and a plurality of shift speeds are set according to a state of engagement / disengagement of the engagement means, and any one of these shift speeds is set. A gear train configured such that there are a plurality of engagement / disengagement combination patterns of the engagement means for setting a gear, wherein a gear to be set is determined based on traveling conditions. In the case where the gear position determined by the gear position determining means and the gear position determined by the gear position determining means are a plurality of types of combination patterns of the engagement / release of the plurality of engagement means, the engagement / release of the engagement / release A shift stage setting unit that outputs an engagement / disengagement combination pattern in which a shift is achieved by engaging a small diameter clutch among the combination patterns.