JPS61165055A - Speed change control mechanism for electronic control type automatic transmission - Google Patents

Abstract

PURPOSE:To make a failsafe mechanism and an inhibit mechanism compatible while to retard reversing of speed changer even upon reversing of a manual valve under high speed travel. CONSTITUTION:Upon malfunction of electronic control, power is interrupted from first and second solenoid valves 60, 110 to enter into 4th speed shift condition. When shifting a manual valve 40 to 3rd speed, it will enter into same condition with 4th speed shift because there is no corresponding oil path. Upon shifting to 2nd speed range, a high pressure signal from an oil path 9 will function onto 3-4 shift valve 90 thus to enter into 3rd speed shift. While upon shifting to 1st speed range, an oil path 1 will communicated through a shuttle valve 180 with an oil path 10 to function a high pressure signal onto a safety valve B thus to achieve 1st speed shift. Upon shifting to reverse range, a high pressure signal from an oil path 12 will lift 3-4 shift valve 90 while lower 1-2 shift valve 70 thus to achieve reversing.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a shift control mechanism of an electronically controlled automatic transmission, and particularly to a shift control mechanism for an electronically controlled automatic transmission, in particular a shift valve that operates a friction engagement member of an automatic transmission so that each shift valve can be operated by a manual valve. This relates to improvements to the hydraulic circuit.

[Prior Art] This type of automatic transmission has a plurality of planetary gear sets, as seen in Japanese Patent Application No. 58-136542 and Japanese Patent Application No. 58-13589, and each element is appropriately selected by a friction engagement member. This determines the gear ratio. Frictional engagement members are generally driven by hydraulic pressure,
The oil passages from the pressure source to each friction engagement member are selected by controlling three shift valves with two solenoid valves. Control is performed by electronically controlling solenoid valves to open and close them according to operating conditions.Normally, the fourth speed is obtained when both solenoid valves are closed. This is to act as a fail-safe function in case the electronic control malfunctions while driving. Further, when one of the two solenoid valves, for example, the second solenoid valve, is open, the first speed is set.

The electronic control operates when the manual valve is in range. When the shift position of the manual valve is in a travel range other than the drive range, shifting of the corresponding shift valve is restricted to prevent upshifting. However, when downshifting by operating the manual valve,
Some models are equipped with an inhibit mechanism that prevents downshifting unless the vehicle speed drops below a certain level if the engine overruns.

When shifting an automatic transmission to neutral or reverse, it is usually done by operating only a manual valve.

In general, electronically controlled automatic transmissions are easy to operate as they allow you to obtain a gear ratio that matches the driving conditions by simply operating the accelerator pedal, but since there is a possibility that the electronic control may malfunction, they are equipped with a fail-safe mechanism that matches the driving conditions. Manual operation is now possible.

[Problems to be Solved by the Invention] In a shift control mechanism that gives priority to the shift position of the manual valve over electronic control, when downshifting is performed by manual operation while driving at high speed, for example, while driving in 4th gear, Engine may overrun. Engine overruns not only cause discomfort to the driver, but also have a negative effect on fuel efficiency and the engine.To prevent such overruns, it is best to prioritize electronic control and downshift according to driving conditions. , the inhibit mechanism will not work if the electronic control fails.

Furthermore, with conventional transmission control mechanisms, if the manual valve is accidentally set to reverse range while driving at high speed, there is a high risk that the transmission will go into reverse.

The present invention has been made to solve the above problems, and its purpose is to provide both a fail-safe mechanism and an inhibit mechanism, and also to prevent the transmission from immediately switching to reverse even if the manual valve is accidentally set to reverse range while driving at high speed. An object of the present invention is to provide a shift control mechanism for an electronically controlled automatic transmission that is difficult to access.

[Technical Means for Solving the Problems] The present invention provides a shift control mechanism for the electronically controlled automatic transmission, in which an oil passage related to the first and second solenoid valves is provided when the first solenoid valve is closed. A valve mechanism is provided that uses the high pressure signal of the manual valve and the output signal of the first speed range or reverse range (R) of the manual valve as input signals to set the oil passage communicating with the second solenoid valve at the same signal pressure as when the second solenoid valve is opened. , 3-4 as an oil path corresponding to the second speed range of the manual valve.
The above object was achieved by configuring an oil passage for shifting the shift valve to the third speed side and not configuring an oil passage corresponding to the third speed range. As an example, a high pressure signal is output when the second solenoid valve is closed, and the valve mechanism outputs the same signal pressure (no pressure or low pressure) as when the second solenoid valve is opened by discharging pressure from the oil passage communicating with the second solenoid valve. achieved.

[Function] If the electronic control fails while driving with the manual valve set to drive range (D), the first and second solenoid valves will close regardless of the automatic transmission gear ratio. and goes into 4th gear.

At this time, the driver must manually select the manual valve shift position according to the driving condition.When the manual valve shift position is set to the 3rd gear range, there is no corresponding oil passage, so the automatic The transmission remains in fourth gear. In the conventional transmission mechanism, the gear immediately shifts to third gear, but since downshifting during high-speed driving can lead to engine overrun, in the present invention, the gear remains in fourth gear and has an inhibit function. When the manual valve shift position is set to 2nd gear range, the oil passage communicates with the boat that shifts the 3-4 shift valve to 3rd gear, so the automatic transmission shifts to 3rd gear and when downshifting. acts as an inhibit function during manual operation.

When the shift position of the manual valve is set to the 1st speed range, the output signal of the 1st speed range, for example, a high pressure signal, and the high pressure signal when the first solenoid valve is closed are used as input signals to control the oil communication with the second solenoid valve. Since the valve mechanism that opens the path operates, the same condition as closing the first solenoid valve and opening the second solenoid valve is obtained. This state is the same as shifting an automatic transmission to first gear under electronic control. Therefore, when the manual valve shift position is set to the 1st gear range,
The automatic transmission shifts to W41 speed via the valve mechanism.

When the shift position of the manual valve is set to reverse range (R), according to the above example, the first
A state is created in which the solenoid valve is closed and the second solenoid valve is opened, and the automatic transmission is reversed by further controlling a specific shift valve.In the present invention, unless the first solenoid valve is closed, reverse is achieved. Therefore, if a reverse shift is made by mistake while driving at high speed (2nd to 3rd forward speed), the first solenoid valve is open, so the reverse shift will be prevented.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

Pressure oil from an oil pump 20 is supplied to the oil passage 1 corresponding to line pressure after being pressure regulated by a pressure regulating valve 30. The oil passage 1 branches into four parts, - is connected to the input boat 41 of the manual valve 40, and 2 is connected to the first solenoid valve 6 via the orifice 50.
0, also communicates with the back pressure port 71 of the 1-2 shift valve 70- and the back pressure port 91 of the 3-4 shift valve 90, and connects to the second solenoid valve 110 via the three-way orifice 100.
In addition, the back pressure port 72 opposing the above-mentioned back pressure port door 1 of the 1-2 shift valve 70 and the back pressure port 81 of the 2-3 shift valve 80 are connected to the input port door 3 of the 1-2 shift valve 70. Communicate.

The shift position of manual valve 40 is drive range (D)
, oil passage 1 and oil passage 2 communicate with each other. The oil path 2 is branched, and a trimmer valve 120 is installed in parallel to connect the automatic transmission 1.
30, and the others communicate with the input port door 4 of the 1-2 shift valve 7o. Oil passage 2 is 1-
When the spool 75 of the 2-shift valve 70 is at the upper position in the figure (
When the spool 83 is lower in the illustration (left side in the illustration), it communicates with the oil passage 4 and reaches the input boat 82 of the 2-3 shift valve 8o (left side in the illustration), it communicates with the oil passage 4 and reaches the input boat 82 of the 2-3 shift valve 8o. 9
0 input port 92 is reached.

When the spool 75 of the 1-2 shift valve 70 is in the lower position in the figure (right side in the figure), the oil passage 1 of the input port door 3 communicates with the oil passage 5. The oil passage 5 has a trimmer valve 140 arranged in parallel and communicates with a friction engagement member (brake) B3 of the automatic transmission 130. Note that a high pressure signal is applied to both back pressure ports of the 1-2 shift valve 70) 71.72> Fuser+1.7 E l↓rMR-
w L 714 u il & ↓q2-3 shift valve 80
When the spool 83 is at the upper side in the figure (right side in the figure), the oil passage 3 of the input port 82 communicates with the oil passage 6. The oil passage 6 has a trimmer valve 150 arranged in parallel and communicates with a friction engagement member (brake) B2 of the automatic transmission 130.

When the spool 93 of the 3-4 shift valve 90 is in the upper position in the drawing (3 (right side in the drawing)), the oil passage 4 of the input port 82 communicates with the oil passage 7 . The oil passage 7 has a trimmer valve 160 arranged in parallel and communicates with a friction engagement member (brake) Bl of the automatic transmission 130.

On the contrary, when the spool 93 is at the lower side in the figure (left side in the figure).

The oil passage 4 communicates with an oil passage 8. Oil passage 8 is trimmer valve 170
are arranged in parallel and communicated with the friction engagement member (clutch) C2 of the automatic transmission 130.

The oil passage is not configured when the shift position of the manual valve 40 is in the third speed range (3).

When the shift position of the manual valve 40 is in the second speed range (2), the oil passage 1 and the oil passage 9 communicate with each other. Oil passage 9 is 3-
4' communicates with a back pressure port 96 opposite to the back pressure port 91 of the shift valve 9o.

When the shift position of the manual valve 40 is in the first speed range (1), the oil passage 1 and the oil passage 10 communicate with each other. The oil passage 10 communicates via a shuttle valve 180 with an input port 191 of a safety valve B that constitutes a valve mechanism 190. In the safety valve B, the oil passage 1 of the first solenoid valve 60 communicates with the back pressure port 192, and a high pressure signal pushes down the spool 193 (left side in the figure), thereby communicating the oil passage 10 with the oil passage 11. The oil passage 11 communicates with a back pressure port 196 of the other safety valve A that constitutes the valve mechanism 190.

The high pressure signal of the oil line 11 is sent to the spool 197 of the safety valve A.
is pushed up to communicate the oil passage 1 of the second drain valve 110 with the drain port.

At the above-mentioned shift position, the oil passage 1 and the oil passage 2 are in communication, but when the shift position of the manual valve 40 is in the neutral range (N), the oil passage 1 and the oil passage 2 are cut off. At this time, when the vehicle speed is in the first speed state (including when the vehicle is stopped), the first solenoid valve is closed and the second solenoid valve is open, so the 1st and 2nd shift valves 70 are in the state on the right side in the figure. Therefore, oil path 7
3 and the oil passage 51 communicate with each other, and communicate with the frictional engagement member B3.

The shift position of manual valve 40 is reverse range (R)
, oil passage 1 and oil passage 12 communicate with each other. Oil line 12
branches and communicates with the input port 192 of the safety valve B via the shuttle valve 180 described above. The main flow of the oil passage 12 communicates with a back pressure port 94 opposing the back pressure port 91 of the 3-4 shift valve 90 and an input port 95 . Oil road 1
When the high pressure signal acts on the back pressure port 94, the spool 93 of the 3-4 shift valve 90 rises, and the oil passage 12, that is, the input port 95, communicates with the oil passage 8.

Automatic transmission [3130] has two planetary gear sets connected in series, and friction engagement members 01 to B that control each element.
3 as shown in Table 1, a desired gear ratio can be obtained. The internal configuration of the automatic transmission itself 130 is not related to the present invention, so a description thereof will be omitted.

Ward 1 The O mark in the table indicates engagement of the frictional engagement member.

In order to obtain the engagement of the frictional engagement members C1 to B3 shown in Table 1, the first and second solenoid valves 60.110 are
It is controlled as shown in the table.

In Table 2, the action of the solenoid valve being closed when the solenoid valve is closed when the current is de-energized is indicated by the mark X.The operation can be briefly described as follows.

The shift position of the manual valve 40 is dry plane 1 (D
) to the first speed range (1), the oil passage 2 communicates with and engages the friction engagement member C1.

When shifting to 4th speed, the first and second solenoid valves 60
, 110 are de-energized and closed. A high pressure signal is sent to the back pressure port 71.72 of the 1-2 shift valve 70, and the 2-3 shift valve 80
and the back pressure port 91 of the 3-4 shift valve 90. The oil passage 2 engages the friction engagement member C2 via the oil passages 3 and 4.8.

When shifting to third speed, the first solenoid valve 60 is energized and opened, and the second solenoid valve 110 is de-energized and closed. At this time, the spool 93 of the 33-4 shift valve 90 is positioned upward (to the right in the figure) by the action of the spring, and the oil passage 4 communicates with the oil passage 7.

Therefore, the frictional engagement member B1 is engaged.

When shifting to 2nd speed, first and second solenoid r*5n
-tto no f? L is also energized and becomes a barrier, 1-2.
The shift valves 70, 80, and 90 of 2-3, 3-4 are positioned upwardly (on the right side in the figure) by the action of springs, and the oil passages 3 and 6 communicate with each other. Therefore, the frictional engagement member B2 is engaged.

When shifting to the first speed, the first solenoid valve 60 is de-energized and closed, and the second solenoid valve 110 is energized and opened.

The spool of the 1-2 shift valve 70 is positioned upward fa (left side in the figure) to block the oil passage 2 and instead communicate the oil passage 1 with the oil passage 5. Therefore, the frictional engagement member B3 is engaged.

Manual operation is also performed when the electronic control malfunctions, so the explanation will include that malfunction. If the electronic control fails, the first and second solenoid valves 60.110 will be de-energized, similar to the state of the fourth gear shift.

When the shift position of the manual valve 40 is set to the third speed range (3), it is the same as the fourth speed shift because there is no corresponding oil passage.

When the second speed range (2) is selected, the oil passage 1 communicates with the oil passage 9. The high pressure signal of the oil passage 9 acts on the back pressure port 96 of the 3-4 shift valve 90, and the spool 93 is positioned upward (on the right side in the figure), thereby communicating the oil passage 4 and the oil passage 7. Therefore, the shift is to third gear.

When the first speed range is selected, oil path 1 is the shuttle valve 18.
It communicates with the oil passage lO via 0. A high pressure signal from the oil passage 10 acts on the input port 191 of the safety valve B. At this time, when the first solenoid valve 60 is de-energized and a high pressure signal is acting, that is, when the electronic control is malfunctioning, the high pressure signal acts on the back pressure port 192 of the safety valve B and causes the spool 193 to move downward ( (on the left side in the illustration) and press down on the oil path 10.
and the oil passage 11 are communicated with each other. The high pressure signal in the oil passage 11 acts on the back pressure boat 196 of the safety valve A, and the spool 19
7 upwards (to the right in the figure). With this operation, the oil passage 1 of the second solenoid valve 110 communicates with the drain port. Therefore, the second solenoid valve 110 is energized,
A first gear shift is achieved. Shift position of manual valve 40 increases, 3, 2. and N, safety valve A does not operate.

When set to neutral range N, oil path 1 is the other oil path 2.
, 9, 10, and 12, the friction engagement member (clutch) CI is released and neutral is achieved.

When in reverse range (R), oil passage 1 and oil passage 12
communicate. The high pressure signal of the oil line 12 is the 3-4 shift valve 90.
The spool 93 of the l-2 shift valve 70 is raised (to the right side in the figure) to connect the oil passage 4 and the oil passage 8 and engage the frictional engagement member (clutch) C2, and the valve mechanism 190 is operated to lower the spool 75 of the l-2 shift valve 70. is located below (on the right side in the figure), and the oil passages 1 and 5 are communicated with each other to connect the friction engagement member (brake) B.
3 to achieve reverse.

[Effect] As explained above, according to the present invention, an oil passage corresponding to the 3rd speed range is not configured in the → manual valve, and the 3-4 shift valve is operated as an oil passage corresponding to the 2nd speed range. Since an oil passage is provided to prevent the failure of the electronic control, it is now possible to have both a fail-safe mechanism and an inhibit mechanism even when the electronic control fails.

Furthermore, according to the present invention, since the valve mechanism (safety valves A and B are installed in the first gear range), it is possible to detect the presence or absence of a failure in the electrical system, that is, the electronic control, and only in the event of a failure, the manual signal will be used to influence gear shifting. Furthermore, since the valve mechanism is also related to the reverse range, it can be provided with a kind of inhibit function.

Furthermore, from the viewpoint of the entire speed change control mechanism, each shift valve and manual valve are simplified, valve sticks are reduced, and reliability is improved.

Another advantage of the present invention is that four speeds can be achieved with three shift valves and two solenoid valves.

[Brief explanation of drawings] The drawing is a hydraulic circuit diagram showing an embodiment of the present invention. 1 to 12...oil line, 40...manual valve. 50.100... Orifice. 70...1-2 shift valve. 80...2-3 shift valve. 130... Automatic transmission. 90...3-4 shift valve. 180...Shuttle valve. 190... Valve mechanism. A, B...Safety valve. CI, C2, Bl, B2. B3 ...Frictional engagement member.

Claims (1)

[Claims] 1-2, 2-3, selectively communicating an oil passage of each frictional engagement member that determines a gear ratio of an automatic transmission with an oil passage from a pressure source;
A manual for selectively connecting the oil passage from the pressure source to the oil passage communicating with the shift valve or the oil passage controlling the shift valve according to each shift by manual operation with each shift valve in 3-4. valve, and first and second solenoid valves that act on each shift valve as a signal pressure using hydraulic pressure from a pressure source by opening and closing according to predetermined operating conditions when the manual valve is in the travel range. Second
In a shift control mechanism of an electronically controlled automatic transmission, the automatic transmission is in fourth gear when both solenoid valves are closed, and is in first gear when the first solenoid valve is closed and the second solenoid valve is open. , a high pressure signal when the first solenoid valve is closed and an output signal of the first speed range or reverse range (R) of the manual valve are input signals in the oil passages related to the first and second solenoid valves, and the second solenoid is connected to the second solenoid valve. A valve mechanism is provided that makes the oil passage communicating with the valve have the same signal pressure as when the second solenoid valve is opened, and an oil passage that shifts the 3-4 shift valve to the 3rd speed side is provided as an oil passage corresponding to the 2nd speed range of the manual valve. A shift control mechanism for an electronically controlled automatic transmission, characterized in that an oil passage corresponding to a third speed range is not constituted.