JPH0130024B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a hydraulically operated transmission used in an automobile or other vehicle.

(Prior art) As a conventional device of this kind, Japanese Patent Publication No. 49-40585 discloses a hydraulically operated transmission that automatically changes gears from 2nd gear to 3rd gear by switching operation of a shift valve.
an oil drain control valve that is interposed in an oil drain path connected to a second speed hydraulic engagement element via a shift valve and is pressed to the open side by the hydraulic pressure of a third speed hydraulic engagement element during a speed change; When shifting from 3rd gear to 4th gear, the oil drain passage is connected to the 3rd gear hydraulic engagement element via a shift valve.
An oil drain control valve is provided that is pressed to the open side by the hydraulic pressure of the hydraulic engagement element for speed, and when these gears are changed, the hydraulic pressure of the hydraulic engagement element for 2nd and 3rd gear on the oil drain side is applied to the 3rd gear on the oil supply side. The oil pressure of the oil pressure engaging element for engine and 4th speed rises to a predetermined pressure, and the oil drain control valve is lowered relatively slowly until it is opened, and then it is lowered relatively suddenly. It is known that the release timing of the oil-side hydraulic engaging element is controlled to achieve smooth gear shifting.

(Problems to be Solved by the Invention) In the above-mentioned prior art, depending on the driving conditions,
When the shift characteristics are set so that a direct shift from 2nd gear to 4th gear is performed, the oil drain control valve installed in the oil drain path connected to the 2nd gear hydraulic engagement element changes the speed from 2nd gear to 4th gear. When changing the speed, unlike when changing from second to third speed, hydraulic pressure is not applied to press the valve toward the opening side, making it impossible to appropriately control the release timing of the second speed hydraulic engagement element.

Focusing on this problem, the present invention has been developed not only when shifting from a first transmission system to a second transmission system that is adjacent to each other in the permutation of gear stages, but also when shifting between the first transmission system and the second transmission system. Even when directly changing speed from the first transmission system to the third transmission system located on the opposite side of the transmission system, the release timing of the hydraulic engagement element that establishes the first transmission system is appropriately controlled. The purpose is to provide a device that allows smooth gear shifting.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an oil drainage control interposed in an oil drainage path connected to a first hydraulic engagement element that establishes a first transmission system. In addition to the hydraulic pressure of the second hydraulic engagement element that establishes a second transmission system as hydraulic pressure that presses the valve toward the opening side, a third hydraulic pressure that establishes a third transmission system
The hydraulic engagement element is characterized in that the hydraulic pressure of the hydraulic engagement element is applied.

(Example) The present invention will be explained with reference to the illustrated embodiments.

In FIG. 1, reference numeral 1 denotes a transmission that changes gears into four forward speeds and one reverse speed, and the transmission 1 includes an input shaft 1a connected to an engine 2 via a torque converter 3;
Transmission systems G1, G2, G3, G4 for forward gears 1 to 4 and reverse transmission system GR are connected to the output shaft 1b connected to the drive wheels 4 of the vehicle via the differential gear 5.
and each forward transmission system G1, G2, G3,
The first to fourth gear hydraulic clutches C1, C2, C3, and C4, which are hydraulic engagement elements, are intervened in G4.

The reverse transmission system GR shares the 4-speed transmission system G4 and the 4-speed hydraulic clutch C4, and both transmission systems G4 and GR are connected to the selector gear 6 on the output shaft 1b.
It was established selectively via .

In the drawing, 7 is a one-way clutch interposed in the first-speed transmission system G1, which operates to allow over-rotation of the output shaft 1b. Each of the hydraulic clutches C1, C
2, C3, and C4 have their oil supply and drainage controlled by, for example, a hydraulic circuit shown in FIG. "R" for reverse, "N" for neutral, "D ₄ " for automatic shifting between 1st and 4th gears, 1
A manual valve 9 that can be freely switched to 6 positions: "D ₃ " for automatic shifting between speeds and 3rd speed, and "2" for holding 2nd speed;
The manual valve 9 is equipped with a shift valve 10 that is switched and operated according to the vehicle speed and throttle opening, and a servo valve 11 for switching forward and backward movement that connects the selector gear ₆ described above. The first oil passage L1 connected to the source 8 is the second oil passage L connected to the shift valve 10.
2, and oil is supplied to and discharged from the second to fourth gear hydraulic clutches C2, C3, and C4 through the shift valve 10.

The 1st speed hydraulic clutch C1 is always supplied with oil via the 3rd oil path L3 branched from the 2nd oil path L2. As the clutch C2 is refueled, its engagement force is gradually strengthened and the rotational speed of the output shaft 1b exceeds the speed of the first speed transmission system G1 due to torque transmission through the second speed transmission system G1. 1st speed transmission system G1 by clutch 7
Torque transmission via the transmission is automatically stopped, resulting in smooth gear shifting.

Therefore, the problem with gear shifting is that the 2nd to 4th gear hydraulic clutches C2, C3, and C4 are operated by the shift valve 10.
This is a shift at 2nd or higher speeds that switches between supplying and discharging oil.

The shift valve 10 includes a first shift valve 10 ₁ for shifting from 1st to 2nd speed on the upstream side, and a fourth oil passage L4 connected thereto.
A second intermediate shift valve 10 2 for 2nd-3rd speed shifting is connected to the second shift valve 10 ₂ , and a third shift valve 10 2 for 3rd-4th gear shifting on the downstream side is connected to this via a fifth oil passage L5. It consists of a shift valve 10 ₃ and each valve 10 ₁ , 10 ₂ ,
A governor pressure corresponding to the vehicle speed from a governor valve 12 is provided at one end of 10 ₃ , that is, the right end, and a first throttle valve 1 is provided at the left end.
Throttle pressure corresponding to the throttle opening from _3.1 is applied, and as the vehicle speed increases, the governor pressure first moves the first shift valve _10.1 from the 1st speed position on the right side to the 2nd speed position on the left side. , the second oil passage L2 is connected to the sixth oil passage L6 on the outflow side of the second shift valve 10 ₂ via the fourth oil passage L4, and the sixth oil passage L6 is connected to the sixth oil passage L6 on the outflow side of the second shift valve 10 2 at the “D ₄ ” position of the manual valve 9. Hydraulic power source 8 is connected to second-speed hydraulic clutch C2 via seventh oil passage L7 connected to
When oil pressure is supplied from the 1st gear to 2nd gear and the vehicle speed further increases, the second shift valve ₁₀₂ moves from the 2nd gear position on the right side to the 3rd gear position on the left side, and the fourth oil passage L4 is switch-connected from the sixth oil passage L6 to the fifth oil passage L5, and the third-speed hydraulic clutch C is connected via the eighth oil passage L8 on the outflow side of the third shift valve ₁₀₃ .
3 and the sixth oil passage L6 is connected to the second shift valve 10.
₂ to the first oil drain path LD1 to drain oil from the 2nd speed hydraulic clutch C2.
When the vehicle is shifted up to a higher speed and the vehicle speed further increases,
The third shift valve ₁₀₃ moves from the 3rd gear position on the right side to the 4th gear position on the left side, and the 5th oil passage L5 changes to the 8th oil passage L.
8 to the ninth oil passage L9, and the ninth oil passage L
9 at the “D ₄ ” position of the manual valve 9.
The eighth oil passage L8 is connected to the second oil drain passage LD2 via the third shift valve ₁₀₃ to supply oil to the fourth-speed hydraulic clutch C4 through the tenth oil passage L10, and to discharge oil from the third-speed hydraulic clutch C3. Oil was changed and the gear was shifted up from 3rd to 4th gear.

Further, according to deceleration, the third shift valve 10 ₃ returns to the third gear position on the right side, and the ninth oil passage L9 is connected to the third oil drain passage LD3 and the eighth oil passage through the third shift valve 10 ₃ . The oil passage L8 is connected to the fifth oil passage L5 as described above,
When oil is drained from the 4th speed hydraulic clutch C4 and oil is refilled to the 3rd speed hydraulic clutch C3, the 4th speed is downshifted to the 3rd speed, and the vehicle speed further decreases, the second shift valve ₁₀₂ shifts to the right 2nd speed. Return to position and move to the 8th
The oil passage L8 is connected to the fifth oil passage L5 and the second shift valve 10 ₂
The fourth oil drain path LD4 and the sixth oil path L6 are connected to the fourth oil path L4 as described above through the drain oil from the third speed hydraulic clutch C3 and the second speed hydraulic clutch C2.
refueling and downshifting from 3rd gear to 2nd gear.

In the drawing, 14 is a regulator valve that regulates the hydraulic pressure supplied from the hydraulic source 8 to a constant line pressure, 15 ₁ , 15
₂ , 15 ₃ are respective hydraulic clutches C2 for 2nd to 4th speeds,
7th oil passage L7 and 8th oil passage L8 connected to C3 and C4
and the tenth oil passage L10 are shown, and the respective accumulators 15 ₁ , 15 ₂ , 15 are shown.
Throttle pressure corresponding to the throttle opening degree from the second throttle valve ₁₃₂ was applied to each of the valves _{3 and 3} as back pressure.

In addition, each of the oil drain passages LD1, LD2, LD3, LD4
are drain oil control valves 16 ₁ , 16 ₂ , 16 ₃ , 1, respectively.
6 ₄ and parallel apertures 17 ₁ , 17 ₂ , 17 ₃ , 1
7 ₄ and the control valves 16 ₁ , 16 ₂ , 16 ₃ ,
16 By closing and opening the valves of ₄ , each oil drain path LD1, LD2,
The conduit resistance of LD3 and LD4 is variably controlled in two stages, large and small.

Here, the first oil drain control valve ₁₆₁ , which is interposed in the first oil drain path LD1 connected to the 2nd speed hydraulic clutch C2 at the time of shift up from 2nd speed to 3rd speed, controls the oil pressure of the 3rd speed hydraulic clutch C3. A pilot oil passage L8a branched from the continuous eighth oil passage L8 acts to press the valve toward the opening side, and a second hydraulic clutch C3 connected to the 3rd gear hydraulic clutch C3 when shifting from 3rd gear to 4th gear. The second oil drain control valve ₁₆₂ provided in the oil drain path LD2 controls the oil pressure of the 4-speed hydraulic clutch C4 to the opening side via the pilot oil path L10a branched from the 10th oil path L10 connected thereto. Thus, when shifting from 2nd gear to 3rd gear and from 3rd gear to 4th gear, the 3rd gear on the engagement side is pressed.
When the oil pressure of the first and fourth speed hydraulic clutches C3 and C4 rises to a predetermined pressure, the oil drain control valves 16 ₁ and 1 are activated.
6 ₂ is pushed toward the opening side on the left side in the drawing against the spring 16a, and before and after this, a difference is made in the pressure reduction characteristics of the hydraulic pressure of the hydraulic clutches C2 and C3 of the 2nd and 3rd gears on the releasing side. , the release timing is appropriately controlled, and smooth upshift operation can be obtained without engine stalling due to engine revving or excessive co-engagement.

Also, when downshifting from 4th gear to 3rd gear, the third oil drain control valve ₁₆₃ , which is interposed in the third oil drain path LD3 connected to the 4th gear hydraulic clutch C4, controls the oil pressure of the 3rd gear hydraulic clutch C3 to the pilot oil pressure. It acts to push the valve toward the opening side through the oil passage L8a, and also acts on the 3rd speed hydraulic clutch C3 when downshifting from 3rd gear to 2nd gear.
The fourth oil drain control valve ₁₆₄ , which is interposed in the fourth oil drain path LD4 connected to the fourth oil drain path LD4, controls the hydraulic pressure of the second-speed hydraulic clutch C2 through a pilot oil path L7a branched from the seventh oil path L7 connected thereto. The valve is actuated to be pressed toward the opening side, and thus, when downshifting from 4th gear to 3rd gear and from 3rd gear to 2nd gear, the hydraulic clutches C4 and C3 of 4th gear and 3rd gear, respectively, are released. 3rd and 2nd speed hydraulic clutch C on the engagement side
3. Each oil drain control valve 16 due to increase in oil pressure of C2.
By opening the valves ₃ and 16 ₄ , a difference in speed is established, resulting in smooth downshift operation.

Above, we have explained the shift from 2nd to 3rd gear and 3rd to 4th gear, but under driving conditions such as sudden accelerator operation, it may be possible to skip 3rd gear and shift between 2nd and 4th gears. that is, the second shift valve 10
₂ and 3 shift valves 10 ₃ are simultaneously moved to the left to directly shift from 2nd to 4th gear, or both shift valves 10 ₂ and 10 ₃ are simultaneously moved to the right to shift from 4th to 2nd gear. In some cases, the shift characteristics are set so that a direct downshift is performed. Therefore, in the illustrated embodiment, in accordance with the characteristics of the present invention, the shift up from 2nd gear to 4th gear is taken into account, and the 2nd gear First drain oil control valve 16 corresponding to hydraulic clutch C2
In addition to the hydraulic pressure of the _3rd speed hydraulic clutch C3 mentioned above, the hydraulic pressure of the 4th speed hydraulic clutch C4 is applied as the hydraulic pressure to push the gear 1 toward the opening side, and also the downshift from 4th gear to 2nd gear is applied. In consideration, in addition to the aforementioned hydraulic pressure of the 3rd speed hydraulic clutch C3, the hydraulic pressure of the 2nd speed hydraulic clutch C2 is used as the hydraulic pressure for pushing the third drain oil control valve ₁₆₃ corresponding to the 4th speed hydraulic clutch C4 toward the opening side. Oil path L7
It acted through a.

(Function) The function of the present invention will be explained based on the above-mentioned embodiments. Two transmission systems which are adjacent to each other in a sequence to the upshift side of the second or higher gears where the smoothness of the gear change is a problem. As described above, the shift from the speed transmission system G2 to the third speed transmission system G3, which is the second transmission system, is controlled by the hydraulic pressure of the third speed hydraulic clutch C3 of the first oil drain control valve ₁₆₁ . The release timing is appropriately controlled and carried out smoothly, and this point is not particularly different from that of the conventional device described above. However, according to the present invention, the third speed transmission system G3 is skipped from the second speed transmission system G2. Even when shifting directly to the 4-speed transmission system G4, which is the third transmission system,
Since the hydraulic pressure of the 4-speed hydraulic clutch C4 is applied to the first oil drain control valve 16 ₁ to push the valve toward the opening side, the operation of the valve 16 ₁ is controlled by the hydraulic pressure of the 4-speed hydraulic clutch C4. As a result, the release timing of the 2nd speed hydraulic clutch C2 is appropriately controlled in the same way as when shifting up from 2nd speed to 3rd speed, and a smooth upshift operation from 2nd speed to 4th speed can be obtained.

Also, when downshifting from 4th gear to 2nd gear, the third oil drain control valve 16 ₃ corresponding to the 4th gear hydraulic clutch C4
In addition to the hydraulic pressure of the third-speed hydraulic clutch C3, the hydraulic pressure of the second-speed hydraulic clutch C2 acts to press the valve toward the opening side, so that the valve ₁₆₃ is operated by the hydraulic pressure of the second-speed hydraulic clutch C2. The control appropriately controls the release timing of the 4th speed hydraulic clutch C4, resulting in smooth downshift operation.

The above description has been about a 4-speed transmission, but if it is a 5-speed transmission and it is possible to directly shift up from 2nd to 5th speed, it will correspond to the 2nd speed hydraulic engagement element. In addition to the pressure of the 3rd and 4th gear hydraulic engagement elements, the pressure of the 5th gear hydraulic engagement element may be used as the hydraulic pressure to press the drain oil control valve toward the opening side. If it is possible to directly shift up to a higher speed, the hydraulic pressure for pressing the oil drain control valve corresponding to the 3rd gear hydraulic engagement element toward the open side is applied in addition to the pressure of the 4th gear hydraulic engagement element. It is sufficient to apply the hydraulic pressure of the hydraulic engagement element. In addition, the throttle pressure and the hydraulic pressure of the hydraulic engagement element on the releasing side corresponding to the valve are applied as hydraulic pressure to press the oil drain control valve toward the closing side, and the pressure necessary for opening the valve is pushed toward the opening side. The value of the oil pressure of the hydraulic engagement element on the engagement side may be changed in accordance with the throttle valve opening of the engine or the pressure drop state of the hydraulic engagement element on the disengagement side.

Furthermore, the present invention is of course applicable to transmissions using planetary gear mechanisms, which are equipped with hydraulic engagement elements such as hydraulic brakes other than hydraulic clutches.

(Effect of the invention) As described above, according to the present invention, the gears are changed from the first transmission system that is not adjacent to each other in the sequence of gears to the third transmission system by skipping the second transmission system located in the middle. Even in this case, the oil drain control valve that controls draining oil from the first hydraulic engagement element that establishes the first transmission system is operationally controlled by the hydraulic pressure of the third hydraulic engagement element,
The release timing of the first hydraulic engagement element is appropriately controlled to achieve smooth gear shifting, and unlike those that provide a separate control valve, a second transmission system is established in the conventional oil drain control valve. This is a simple change in which the hydraulic pressure of the third hydraulic engagement element is applied to press the valve toward the opening side in addition to the hydraulic pressure of the second hydraulic engagement element, which is advantageous in terms of cost. has.

[Brief explanation of drawings]

FIG. 1 is a diagram of an example of a transmission to which the device of the present invention is applied, and FIG. 2 is a hydraulic circuit diagram thereof. 1...Transmission, G1, G2, G3, G4...1
Speed to 4 speed transmission system, C1, C2, C3, C4...
...1st to 4th speed hydraulic clutch (hydraulic engagement element),
LD1, LD2, LD3, LD4...Drainage path, 10...
...Shift valve, 16 ₁ , 16 ₂ , 16 ₃ , 16 ₄ ...Drain oil control valve.

Claims (1)

[Claims] 1. A first transmission system and a second transmission system that are adjacent to each other in the sequence of gear stages, and a third transmission system that is located on the opposite side of the first transmission system with the second transmission system in between. A hydraulically actuated transmission for a vehicle, which selectively establishes each transmission system by controlling the supply and drainage of oil to each hydraulic engagement element that establishes each transmission system using a shift valve, An oil drain control valve that increases or decreases the flow resistance of the oil drain path is interposed in the oil drain path that is connected to the first hydraulic engagement element that establishes the first transmission system via the shift valve. , the drain oil control valve is connected to the second
In the device that presses the oil drain control valve to the opening side to reduce the flow path resistance by the hydraulic pressure of the second hydraulic engagement element that establishes the third transmission system, 1. A control device for a hydraulically operated transmission for a vehicle, characterized in that it is configured to be pressed toward the opening side by the hydraulic pressure of a hydraulic engagement element.