JPH03292453A - Shift controlling method for planetary gear type automatic transmission - Google Patents

Abstract

PURPOSE:To simplify the extent of shift control by constituting it to complete a speed change from a first shift speed to other shift speeds by shifting to the other shift speeds by way of the third shift speed from the first shift speed. CONSTITUTION:When release between a first clutch K1 and a third brake B3 and engagement between a second clutch K2 and a first brake B1 both should be done simultaneously just as gear shifting from second to third, the gear shifting from second to fourth is carried out once, and then the gear shifting from fourth to third is carried out, thus shift control from the second to the third is made so as to be done. At time of shifting from the second to the fourth, the first clutch K1 is left engaged intact, the third brake B3 alone is released, and it is good enough to engage only the second clutch K2, and at the time of the gear shifting from the fourth to the third in succession, the second clutch K2 is left engaged intact, and the first clutch K1 alone is released, and it is good enough to engage only the first brake B1, thus the shift control is easily performable.

Description

Detailed Description of the Invention A.9 Objective of the Invention (Field of Industrial Application) The present invention relates to a planetary gear type automatic transmission configured using a plurality of planetary gear trains, and more specifically relates to a planetary gear type automatic transmission configured using a plurality of sets of planetary gear trains. The present invention relates to a speed change control method in a transmission.

(Prior Art) Planetary gear type automatic transmissions are widely used as automatic transmissions for automobiles. The conventional planetary gear type automatic transmission is
There are many transmissions that are constructed by combining two sets of planetary gears, such as the Ravigneau gear train and the Simpson gear train, and in these cases, up to four forward speeds are common. . However, there is a demand for multi-speed gears for the purpose of improving driving characteristics, etc., and for this reason, transmissions having five or more forward speeds have been proposed and some have been put into practical use.

Examples of such a multi-stage transmission include Japanese Patent Application Laid-open No. 63-318349 and Japanese Utility Model Application No. 61-10385.
4, No. 104854, No. 104855, etc., disclose transmissions. This transmission uses a Simpson gear train, and the transmission is constructed by combining two sets of planetary gear trains with three clutches and brakes, respectively. Note that these clutches and brakes are collectively referred to as engagement/disengagement means.

In this transmission, five forward speeds and one reverse speed can be set by selectively engaging the two engaging and disengaging means. Therefore, it is possible to change the speed by changing the engaging/disengaging means.

(Problem to be Solved by the Invention) However, in the case of the above-mentioned transmission, in some gear shifts, two engaging/disengaging means (clutches or brakes) are simultaneously disengaged, and two other engaging/disengaging means (clutches or brakes) are simultaneously disengaged. There is a problem in that the operation of engaging the means is unavoidable, which complicates speed change control. For this reason, for example, it is difficult to set the release and engagement timing and engagement force of each of the two engagement and disengagement means, and it is difficult to set the engagement force of each of the two engagement and disengagement means. There is a risk that all the engaging/disengaging means will be released and the engine speed will increase.

Furthermore, when shifting gears, for example, changes in input rotational speed may be detected and, based on this, the engagement torque of the engaging/disengaging means during gear shifting may be controlled to provide smooth shifting. In the case where two engaging/disengaging means are engaged at the same time, it becomes unclear which engaging torque of which engaging means is affecting the change in the input rotation, and there is a problem that control is difficult.

The present invention has been made in view of such problems, and even in a shift that requires the release of two engaging/disengaging means and the engagement of two other engaging/disengaging means, it is possible to release one engaging/disengaging means and engage one other engaging/disengaging means. It is an object of the present invention to provide a speed change control method that allows a speed change to be performed only by controlling the engagement of a disengaging means.

Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, the present invention provides a mechanism for releasing two engaging and disengaging means and disengaging two different engaging and disengaging means when shifting from one gear to another gear. In the case of a shift that requires engagement of a locking and disengaging means, the first gear is shifted from the first gear to a third gear in which the gear can be shifted by only releasing one of the locking and disengaging means and engaging one of the locking and disengaging means. First, the gear is shifted, and then the gear is shifted from the third gear to the above-mentioned gear simply by releasing one engaging/disengaging means and engaging the one engaging/disengaging means, thereby completing the shifting. I have to.

(Function) When the above-mentioned shift control method is used, from the above-mentioned first gear to the third gear
The shift from the first gear to the above-mentioned gear is completed by shifting to the above-mentioned gear via the gear. Shifting from the third gear to the third gear and shifting from the third gear to the third gear can be performed by only releasing one engagement/disengagement means and engaging one engagement/disengagement means. , speed change control is simple.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

The structure of a planetary gear type automatic transmission whose speed change is controlled by the control method according to the present invention is shown in the skeleton of FIG.

This transmission has two sets of planetary gear trains G and G2 coaxially arranged in parallel with the input shaft 1. The first planetary gear train G includes a first sun gear S1 disposed coaxially with the input shaft 1, and a first sun gear S1 that meshes with the first sun gear S1 and revolves around the first sun gear S while rotating. a first pinion P that rotatably holds the first pinion P1;
The first carrier C1 and the first pinion P that revolve together with the
1 and a first ring gear R8 having internal teeth that mesh with the first ring gear R8.

Further, the second planetary gear train G2 meshes with a second sun gear S2 coaxially arranged in parallel with the first sun gear S, and revolves around the second sun gear S2 while rotating on its axis. The second pinion P2 and the second pinion P
2, and a second ring gear R2 that has internal teeth that mesh with the second pinion P2.

The first sun gear S1 is detachably connected to the input shaft 1 through a first clutch 1, and a first brake B capable of fixing and holding the first sun gear S1;
is installed. The first carrier C8 is detachably connected to the input shaft 1 via the second clutch 2, and is also directly connected to the second carrier C2. Furthermore, the first and second carriers Cs=C2 are equipped with a second brake BQ and a one-way clutch F that can hold the first and second carriers fixedly.
is installed. The first ring gear R1 is removably connected to the input shaft 1 via a third clutch 3, and a third brake B3 is attached to the first ring gear R1, which can hold the first ring gear R1 fixedly. Furthermore, this first ring gear R1 is directly connected to the second sun gear SQ.

Further, the second ring gear R2 is directly connected to the output gear 2.

In the transmission configured by connecting each element (sun gear, carrier, and ring gear), input shaft 1, and output gear 2 as described above, the first to third clutches are connected to the first to third clutches, and the first to third brakes are connected to the first to third clutches. By performing the engagement and disengagement control of B1 to B3, it is possible to set the gear stage and control the speed change. Specifically, as shown in the table in Fig. 2, if engagement/disengagement control is performed, five forward speeds (LOW, IST, 2ND, 3RD) can be achieved.
, 4TH and 5TH) and reverse 1st speed (REV) can be set. Note 1. In this table, the clutch or brake marked Q indicates that it is engaged.

As you can see from this table, 5 forward speeds (LOW to 5TH
) is set by engaging two of the clutch and brake (i.e., engagement/disengagement means), and automatic shift control between these five speeds changes the engagement/disengagement means to be engaged. It is done by

During such speed change control, 2nd speed (2ND) and 3rd speed (
Shifting between adjacent shift ranges other than shifting between 3RD and 3RD) is performed by releasing one engaging/disengaging means and engaging one engaging/disengaging means.

For example, in the case of upshifting from 1st gear (LOW) to 2nd gear (2ND), control may be performed to engage the third brake B3 while keeping the first clutch engaged. The one-way clutch F becomes free when the third brake B3 starts engaging).

Therefore, when shifting up from 1st to 2nd gear, the 3rd gear
As shown in FIG. 3(A), the hydraulic pressure of the third brake B3 is controlled, and the rotation speed of the input shaft 1 is changed accordingly.
The output torque changes as shown in FIG. 3(C). However, in this shift, a change in the rotation speed of the input shaft is detected, and based on this, a sudden change occurs in the rotation speed of the input shaft, and the engagement force of the third brake B3 is controlled (the hydraulic pressure is changed). control) is carried out. That is, from time t1 when the third brake B3 actually starts engaging and the input shaft rotation starts to change to time t2 when the shift is completed, the hydraulic pressure of the third brake B3 is equal to the input rotation speed. It is controlled according to the changes in the speed, and this allows smooth gear shifting.

There is no problem with the above control when only one engaging/disengaging means is engaged during gear shifting, but when shifting from 2nd gear (2ND) to 3rd gear (3RD) in the transmission of this example, , simultaneously releasing the two engaging/disengaging means (releasing the first clutch 1 and the third brake B3) and engaging the two engaging/disengaging means (
If it is necessary to cause the second clutch to engage the first brake B1, it is difficult to perform the above control as is. Therefore, here, 4th gear is selected as the intermediate gear (third gear), and first, the gear is shifted from 2nd gear to 4th gear, and then the gear is shifted from 4th gear to 3rd gear. Shift control from 2nd speed to 3rd speed is performed using the following steps.

As can be seen from Fig. 2, when shifting from 2nd to 4th speed, only the third brake B3 is released while the first clutch remains engaged, and the second clutch is engaged only. The same speed change control as the shift from the first speed to the second speed described above can be performed. Further, when shifting from 4th to 3rd speed, the second clutch is kept engaged and only the first clutch is released (+).
It is sufficient to engage only the first brake B□, and this shift control can also be performed easily.

Note that FIGS. 4(A) and 4(B) show changes in input/output rotational speed and changes in output torque when this speed change control is performed. As can be seen from this graph, when shifting from 2nd to 3rd gear, the shift control from 2nd to 4th gear is performed from time t3 to t4, and from time t4 to time t5, the shift control from 2nd to 4th gear is performed. 2 while maintaining the 2nd clutch, and then control is performed from 4th to 3rd speed from time t6 to t6, and as a result, the shift from 2nd to 3rd speed is controlled.
The shift to the next speed is completed.

C.1 As described in detail, according to the present invention, in the case of a shift requiring the release of two engaging/disengaging means and the engagement of two other engaging/disengaging means, one gear stage First, the gear is shifted from the first gear position to the third gear position where the gear can be shifted by only releasing one engaging/disengaging means and engaging one engaging/disengaging means, and then the one engaging/disengaging means is released from this third gear position. The gear shift is completed by shifting to another gear only by engagement of one engaging/disengaging means, so that the shift from the first gear to the third gear and this To shift from gear 3 to the other gears listed above,
Both can be performed by only releasing one engaging/disengaging means and engaging one engaging/disengaging means, and the speed change control is simple. Therefore, even in the case of a shift that requires the release of two engaging/disengaging means and the engagement of another two engaging/disengaging means, gear co-meshing (gears constituting two power transmission paths engage simultaneously) There is no risk of the engine speeding up due to the release of all engagement/disengagement means.

[Brief explanation of the drawing]

FIG. 1 is a skeleton showing an automatic transmission in which speed change control is performed using the speed change control method according to the present invention, FIG. 3rIIJ and FIG. 4 are graphs showing changes over time in oil pressure, rotational speed, and torque during automatic gear shifting in the above transmission. 1...Input shaft 2...Output gear S,,B
2...Sun gear P□IP2...Pinion C weight tC2...Carrier R1, R2...Ring gear B,, B2. B...Brake Kt -Ka, Ka...Clutch F...One-way clutch

Claims (1)

[Scope of Claims] 1) In a planetary gear type automatic transmission comprising a plurality of planetary gear trains and a plurality of engagement/disengagement means between input and output members, when shifting from one gear to another gear, If it is necessary to release two of the engagement and disengagement means and engage two other of the engagement and disengagement means, one of the engagement and disengagement means must be disengaged between the one gear stage and the other gear stage. After selecting a third gear position in which a gear shift can be performed by only releasing the disengaging means and engaging one of the engagement and disengaging means, and causing the shift from the first gear position to the third gear position, A planetary gear type automatic transmission characterized in that the shift from the third gear to the other gear is performed to complete the shift from the first gear to the other gear. transmission control method.