JPH01288654A - Device for controlling speed change of automatic transmission - Google Patents

Abstract

PURPOSE:To avoid getting into an uncontrollable condition by effecting an intermediate speed change stage of a second gear, etc. at the time of the nonelectrified condition of a solenoid valve. CONSTITUTION:An electronic controller 58 outputs signals for regulating the oil pressure of an oil passage 20 in four stages P1-P4. As the oil pressure of the oil passage 20 is switched over from a P3 condition to a P2 condition, a 2-3 shift valve 26 is switched over form an upper half portion condition to a lower half portion condition. On the other hand, a 3-2 timing valve 40 is kept as an upper half portion position. Hence, the oil pressure in a high-and- reverse clutch H and R/C starts to be discharged whereas, the oil pressure in a servo release chamber S/R is not discharged. After keeping this condition for a certain time, the oil pressure in the oil passage 20 is switched over from P2 to P1. Thereby, even if the oil pressure in the oil passage 20 becomes zero because of the failure of the electronic controller 58 or a solenoid valve 56, an automatic transmission can be temporarily made a neutral condition while, meantime, the engine speed can be increased to followingly obtain a second gear condition.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a speed change control device for an automatic transmission.

(b) Conventional technology As a conventional speed change control device for automatic transmission,
There is one shown in Japanese Patent No. 101152. The shift control device for the automatic transmission shown therein is configured to control four forward speeds by switching four shift valves using one solenoid valve. That is, the solenoid valve is capable of outputting four levels of oil pressure, and the switching characteristics of the shift valves are set so that one shift valve is switched for each step change in the oil pressure. This allows one solenoid valve to
It is possible to change the wooden shift valve.

(c) Problem to be solved by the invention However, in the conventional automatic transmission shift control device as described above, when a solenoid valve is in a failure state, the automatic transmission is switched to the first gear state. There is a problem.

That is, when the solenoid valve becomes de-energized due to a failure or disconnection of the electronic control device, the resulting oil pressure becomes zero, and the automatic transmission enters the first speed state. If such a failure occurs while driving at high speed, the engine will suddenly brake, causing the vehicle to spin or the engine to overrun. Furthermore, if the above-mentioned failure occurs, the first speed is locked, making it difficult to temporarily drive to a repair shop or the like.

The present invention aims to solve these three problems.

(d) Means for Solving the Problems The present invention solves the above problems by realizing an intermediate gear such as second speed when the solenoid valve is de-energized.

That is, the shift control device for an automatic transmission according to the present invention has the following features:
The hydraulic pressure output by the solenoid valve is supplied to the plurality of shift valves to act as a switching signal pressure,
The object is a shift control device for an automatic transmission that is configured to obtain multiple gears in response to multiple stages of oil pressure that change stepwise, respectively, output by a solenoid valve. The present invention is characterized in that the shift valve is configured to be in a state in which an intermediate gear other than the first gear and the highest gear is achieved when the shift valve is energized.

(E) When the operating solenoid valve becomes de-energized, the plurality of shift valves become in a state of realizing intermediate gears other than the first gear and the highest gear (for example, the second gear in the case of three forward gears). Therefore, even if the above-mentioned failure occurs while driving, the vehicle will not become uncontrollable or the engine will be damaged, and the vehicle will continue to drive with the intermediate gear fixed. be able to.

Embodiment (First Embodiment) FIG. 2 shows a schematic diagram of a power transmission mechanism of an automatic transmission with three forward speeds and one reverse speed. This power transmission mechanism consists of a human power shaft I that transmits rotational force from an engine output shaft E via a torque converter T/C, an output shaft O that transmits driving force to the final drive device, a first planetary gear set GI, and a second planetary gear set GI. It has a planetary gear set G2, a high and reverse clutch H&R/C, a forward clutch F/C, a hunt brake B, a low reverse brake L&R/B, and a one-way clutch OWC. The first planetary gear set G1 includes a sun gear S, an internal gear R3, both gears S, and R.
The planetary gear set G2 consists of a carrier PC1 that supports a binion gear PI that meshes with the carrier PC1, and a carrier PC1 that supports a binion gear PI that meshes with the carrier PC1.
2 and a carrier PC2 that supports a pinion gear P2 that meshes with R2 at the same time. Each component is connected as shown. The above power transmission mechanism includes a high and reverse clutch H&R/C, a forward clutch F/C, a hand brake B, and a low and reverse brake L&R/B (one-way clutch 0WC).
By operating in various combinations, each element (S+, S2, R+, R,
, , PC, and PC2) can be changed, thereby making it possible to obtain three forward speeds and one reverse speed by varying the rotational speed of the output shaft O relative to the rotational speed of the human power shaft (2).

FIG. 1 shows only the parts of the hydraulic circuit that are directly related to the present invention. The 1-2 shift valve 10 is composed of a spool 12 and a spring 14, and when the spool 12 is in the lower half position in the figure, it connects the oil passage 16 and the oil passage 18. drain. The position of the spool 12 is determined by the balance between the hydraulic force acting on the boat 22 from the oil passage 20 and the force exerted by the spring 14. Line pressure is always supplied to the oil passage 16 from the manual valve 24 during surface advancement. Note that the oil passage 16 is also connected to the forward clutch F/C.

The 2-3 shift valve 26 is composed of a spool 28 and a splinter 30, and when the spool 28 is in the upper half position in the figure, the oil passage 18 and the oil passage 32 are communicated with each other. Train on Route 32. The state of the spool 28 is determined by the oil pressure acting on the boat 34 from the oil passage 20. The oil passage 18 is connected to a servo apply chamber S/A for applying the bunt brake B.

An oil passage 32 provided with an orifice 31 is connected to a high-ant reverse clutch H&R/C. Further, the oil passage 32 is connected to an oil passage 38 by a check valve 36. The check valve 36 is arranged in a direction that allows oil to flow from the oil path 32 side to the oil path 38 side, but does not allow oil to flow in the opposite direction.

3-2 The timing valve 40 is composed of a spool 42 and a splinter 44, and the spool 42 communicates with the oil passage 32 and the oil passage 38 at the lower half position in the figure, and communicates with the oil passage 32 and the oil passage 38 at the upper half position in the figure. The oil passage 38 and the oil passage 32 are blocked.

The position of the spool 42 is determined by the hydraulic pressure acting on the boat 46 from the oil passage 20. The oil passage 38 is connected to a servo release chamber S/R for releasing the hunt brake B. Note that since the pressure receiving area of the servo release chamber S/R is much larger than the pressure receiving area of the servo apply chamber S/A, the band brake B is always released when hydraulic pressure is applied to the servo release chamber S/R.

The aforementioned oil passage 20 is connected via an orifice 52 to an oil passage 50 to which a constant pressure is always supplied from a pilot pressure valve 48. An opening 54 is provided in the oil passage 20, and a solenoid valve 56 that can open and close this opening 54 is provided. The solenoid valve 56 is duty ratio controlled by a signal from an electronic control device 58. Thereby, the oil pressure in the oil passage 20 can be adjusted to a predetermined oil pressure commanded by the electronic control device 58. Note that the solenoid valve 56 is of a type that closes the opening 54 in proportion to the amount of energization, and in the non-energized state, the opening 54 is completely open.

The electronic control device 58 receives electric signals from a vehicle speed sensor 60, a throttle opening sensor 62, etc., or receives human input.
Based on these signals, the electronic control unit 58 outputs a signal for adjusting the oil pressure in the oil passage 20 in four stages: Pl, P2, P3, and P4. In addition, the magnitude of the hydraulic pressure is P 4 > P 3 >
P 2 > P r. On the other hand, the 1-2 shift valve 10 is set so that when the oil pressure of the boat 22 is less than PA, it is in the lower half of the figure, and when it is greater than PA, it is in the upper half of the figure. Similarly, the 2-3 shift valve 26 is set so that when the oil pressure of the boat 34 is less than P8, it will be in the lower half state in the figure, and when it is greater than Pll, it will be in the two-hand state in the figure. . Also, 3
-2 The hydraulic pressure acting on the boat 46 for the timing valve 40 is also P. In the following cases, the state shown in the lower half of the figure will occur,
It is designed so that when it becomes larger than the PC, it will be in the state shown in the upper half of the figure. The magnitude of these oil pressures is PA>PB>P
It is designed to be C. Furthermore, the relationship between the hydraulic pressures of Pl, P2, P3, and P4 and PA, PB, and PC is as follows: p 4 > P A > P 3 > P n > p2 >
It is designed so that PC>P. This relationship is illustrated in FIG. 3.

By setting the hydraulic characteristics as described above, it is possible to adjust the shift control and the 3-2 shift timing.

First, regarding gear shifting, when the oil pressure in the oil passage 20 reaches P4,
Both the 1-2 shift valve 10 and the 2-3 shift valve 26 are in the upper half state in the figure, and the forward clutch F/
Only C is engaged, resulting in the first speed state. Next, oil path 20
When the oil pressure is set to P2 or P, 1-2 shift valve 1
0 is in the upper half of the figure, while the 2-3 shift valve 26 is in the lower half. Therefore, in addition to the forward clutch F/C, hydraulic pressure is supplied to the servo apply chamber S/A, and the hunt brake B is engaged, so that the automatic transmission is placed in the second speed state. Next, when the oil pressure in the oil passage 20 is set to P3, the 1-2 shift valve 10 is in the state shown in the lower half of the figure.
Further, the 2-3 shift valve 26 is in the state shown in the lower half of the figure. As a result, high and reverse clutch H&R/C
Then, hydraulic pressure is supplied to the servo release chamber S/R, resulting in the third speed state. Since the check valve 36 is provided, the oil pressure in the oil passage 32 is supplied to the servo release chamber S/R regardless of the state of the 3-2 timing valve 40.

Further, the 3-2 timing valve 40 operates as follows. That is, when the oil pressure of the oil passage 20 is R2 and Pl, 3
-2 The position of the timing valve 40 is changed. That is, when the oil pressure P2 is reached, the 3-2 timing valve 40 is in the -L half state, the oil passage 38 is in the blocked state, and conversely, the oil pressure P2 is in the -L half state.
1, the oil passage 32 and the oil passage 38 communicate with each other. Utilizing this, for example, the timing of the 3-2 speed change can be adjusted as follows. That is, the oil pressure of the oil passage 20 is P, and the shape 5
When switching from j3 (i.e. 3rd gear) to R2, 2-
The 3-2 shift valve 26 switches to the second speed state (i.e., switches from the upper half state to the lower half state), while the 3-2 shift valve 26
The timing valve 40 remains in the upper half position. Therefore, although the hydraulic pressure of the high-ant reverse clutch H&R/C begins to be discharged, the servo release chamber S/R
hydraulic pressure is not discharged. After maintaining this state for a predetermined time, the oil pressure in the oil passage 20 is switched from R2 to Pl. As a result, the 2-3 shift valve 26 does not switch while remaining in the lower half state, and the 3-2 timing valve 40 switches from the lower half state to the lower half state, and the oil passage 38 and the oil passage 32 are communicated. . As a result, the hydraulic pressure in the servo release chamber S/R also begins to be discharged. In this way, by delaying the discharge of the hydraulic pressure from the servo release chamber S/R by a predetermined period of time compared to the discharge of the hydraulic pressure from the high-ant reverse clutch H&R/C, the automatic transmission can be temporarily placed in the neutral state, and during this period The engine rotational speed is increased, and then the engine is brought into the second speed state. As a result, a neutral state is inserted between the 3rd and 2nd gear shifts, and the gear can be shifted while reducing the rotational speed difference between the engine side and the automatic transmission side, thereby reducing shift shock. As described above, the neutral time inserted during the 3-2 shift is controlled by the electronic control unit 58 according to the driving conditions, and is always appropriately controlled according to the vehicle speed and throttle opening conditions.

- As mentioned above, in this embodiment, if the electronic control device 58, the solenoid valve 56, etc. malfunction, the oil pressure in the oil passage 20 becomes zero.
Even if it is, the state will be 'frJ 2nd speed as shown in FIG. Therefore, even if a failure occurs while driving at high speed, the engine brake will be applied gently, maintaining the safety of the vehicle, preventing the engine from overrunning, and driving with the second gear fixed. You can continue.

(Second Embodiment) FIGS. 4 and 5 show a second embodiment of the present invention. This second embodiment has a 2-3 shift valve 26 and a 1-2 shift valve 1.
The line pressure (hydraulic pressure in the oil passage 16) is supplied without passing through 0.

In this case as well, the same effect as in the first embodiment can be obtained. In this case, the hydraulic characteristics are set as shown in FIG. 5, for example.

(Third Embodiment) FIG. 6 shows a schematic diagram of a power transmission mechanism of an automatic transmission with four forward speeds and one reverse speed with overdrive. This power transmission mechanism includes a human power shaft 13 to which the rotational force from the engine output @ 12 is transmitted via the torque converter 10, an output shaft 14 that transmits the driving force to the final drive device, a first planetary gear set 15, and a second planetary gear. Group 16, reverse clutch 1
8. High clutch 20, forward clutch 22, overrun clutch 24, low and reverse brake 26
, band brake 28, row one-way clutch 29,
and a forward one-way clutch 30.

Note that the torque converter 10 is a lock-up clutch 1.
1 is built-in. The first planetary gear set 15 is a sun gear S
1, an internal gear R1, and a carrier P that supports the binion Kia P1 that engages with both Kia S1 and R1 at the same time.
ct, and the planetary gear set 16 is composed of a sun gear S2, an internal gear R2, and a carrier PC2 that supports a pinion gear P2 that meshes with both gears S2 and R2 at the same time. The carrier PC1 can be connected to the human power shaft 13 via the high clutch 20, and the sun gear S1 can be connected to the human power shaft 13 via the reverse clutch 18. The carrier PCI is connected via the forward clutch 22 and the forward one-way clutch 30 connected in series thereto, or through the forward clutch 22 and the forward one-way clutch 30.
It can also be connected to an internal gear R2 via an overrun clutch 24 arranged in parallel to the internal gear R2. Sungear S
2 is always connected to the human power lll11113, and the internal gear R1 and carrier PC2 are connected to the output shaft 14.
is always connected. lowant reverse brake 2
6 can fix the carrier PCI, and the hunt brake 28 can fix the sun gear S1. Row one-way clutch 29 is carrier P
It is arranged in such a way that normal rotation of ct (rotation in the same direction as the engine output +1qI112) is allowed, but reverse rotation (rotation in the opposite direction to normal rotation) is not allowed.

The power transmission mechanism includes clutches 18, 20, 22 and 2.
4. By operating the brakes 26 and 28 in various combinations, each element (S
1, Sl, R1, R2, PCl, and PC2), and thereby the rotational speed of the output shaft 14 relative to the rotational speed of the human power shaft 13 can be varied. By operating the clutches 18, 20, 22 and 24 and the brakes 26 and 28 in combination as shown in FIG. 7, four forward speeds and one reverse speed can be obtained. In addition, O marks in Fig. 7 indicate operating clutches and brakes, α1 and α2 are the ratio of the number of teeth of sun gears S1 and Sl to the number of teeth of internal gears R1 and R2, respectively, and the gear ratio is the output This is the ratio of the rotation speed of the human powered shaft 13 to the rotation speed of the shaft 14.

FIG. 8 shows only the parts of the hydraulic circuit that are directly related to the present invention. The 1-2 shift valve 110 is composed of a spool 112 and a spring 114, and the spool 112 is located in the lower half of the figure. At the position, the oil passage 116 and the oil passage 118 are communicated,
At the upper position in the figure, the oil passage 118 is connected to the train 1. The position of the spool 112 is determined by the balance between the hydraulic force acting on the boat 122 from the oil passage 120 and the force of the spring 114. Manual valve 1 is installed in oil passage 116.
Line pressure is always supplied from 24 during forward movement. Note that the oil passage 116 is also connected to the forward clutch 22 and the overrun clutch control valve 40.

The 2-3 shift valve 126 is composed of a spool 128 and a spring 130, and when the spool 128 is at the upper position in the figure, the oil passage 118 and the oil passage 32 are communicated with each other.
In the lower half position in the figure, the oil passage 32 is trained. The state of the spool 128 is determined by the balance between the hydraulic force acting on the boat 34 from the oil passage 120 and the force of the spring 13. The oil passage 118 is connected to a dual application chamber 2A for tightening the band brake 28. The oil passage 3z provided with the orifice 31 is connected to a triple release chamber 3R for releasing the high clutch 20 and hunt brake 28.

The 3-4 shift valve 70 is composed of a spool 71 and a spring 72, and the spool 71 communicates with the oil passage 118 and the oil passage 74 when the spool 71 is in the upper position in the figure, and the oil passage 74 is in communication with the oil passage 74 when the spool 71 is in the lower half position in the figure. Drain 1-. The position of the spool 71 is determined by the balance between the hydraulic force acting on the boat 76 from the oil passage 120 and the force of the spring 72. The oil passage 74 is connected to the fourth speed apply chamber 4A in which the band brake 28 is engaged.

The overrun clutch control valve 40 is composed of a spool 42 and a splinter 44.
At the upper half position in the figure, the oil passage 77 and the oil passage 116 communicate with each other, and at the lower half position in the figure, the oil passage 77 is drained.

The position of the spool 42 is determined by the balance between the hydraulic force acting on the boat 46 from the oil passage 75 and the force of the spring 44. The oil passage 77 is connected to the overrun clutch 24.

The aforementioned oil passage 120 is connected via an orifice 52 to an oil passage 5o to which constant pressure is always supplied from the pilot pressure valve 48. The oil passage 120 is provided with an opening 54, and a solenoid valve 56 that can open and close this opening 54 is provided. The solenoid valve 56 is tute-ratio controlled by a signal from an electronic control device 58. As a result, the hydraulic pressure of the njj path 120 is controlled by the electronic control device 58.
The hydraulic pressure can be adjusted to a predetermined oil pressure commanded by the hydraulic pressure.

In addition, the oil passage 75 described above is connected to the oil passage 5o and the orifice 78, which are always supplied with a constant pressure from the pilot pressure valve 48.
connected via. An opening lower 9 is provided in the oil passage 75, and a solenoid valve 8o capable of opening and closing the opening lower 9 is provided. Solenoid valve 80 is turned on and off by signals from electronic control unit 58. Thereby, the oil pressure in the oil passage 75 can be turned on and off based on commands from the electronic control device 58.

The electronic control device 58 receives electric signals from a vehicle speed sensor 6o, a throttle opening sensor 62, etc.
Based on these, the electronic control device 58 outputs a signal to control the operation of the solenoid valve 56.

The operation of the solenoid valve 56 is controlled by the signal from the electronic control device 58, and the oil pressure in the oil passage 120 is adjusted to Po, P.
2, P3, and P4 (Pl<P2<P3<P4). Also 1-2 shift valve 110.2-
The switching pressure PA, pH and PC of the 3-shift valve 126 and the 3-4 shift valve 70 are set as shown in FIG.

On the other hand, the overrun clutch control valve 4o is in the state shown in the upper half of the figure when the oil pressure is outputted to the oil passage 75 by the solenoid valve 80, and is in the state shown in the lower half of the figure when the oil pressure becomes zero.

-1=By setting the hydraulic characteristics as described above, the speed change control and the overrun clutch 24 can be controlled.

First, regarding gear shifting, when the oil pressure in the oil passage 120 reaches P4, the 1-2 shift valve 110, the 2-3 shift valve 1
26 and 3-4 shift valves 70 are now in the state shown in the upper half of the figure, and only the forward clutch 22 is engaged, resulting in the first speed state.

Next, when the oil pressure in the oil passage 120 is set to PI (=O), 1
-2 shift valve 110.2 to 3 shift valves 126 and 3-4 shift valve 70 are all in the lower half state. Therefore, in addition to the forward clutch 22, hydraulic pressure is also supplied to the 2nd gear apply chamber 2A, and the handbrake 28
is engaged, and the automatic transmission is in the second gear state.

Next, when the oil pressure in the oil passage 120 is set to P2, the 1-2 shift valve 110 and the 3-4 shift valve 70 are in the lower half state in the figure, while the 2-3 shift valve 126 is in the upper half state in the figure. becomes. As a result, high clutches 20 and 3
Hydraulic pressure is supplied to the speed release chamber 3R, resulting in the third speed state.

Next, when the oil pressure in the oil passage 75 is set to P3, the 3-4 shift valve 70 and the 2-3 shift valve 126 are placed in the upper half position, and the 1-2 shift valve 110 is placed in the lower half position. As a result, hydraulic pressure is not supplied to the quad application chamber 4A of the hunt brake 28, resulting in the fourth speed state.

Further, the overrun clutch control valve 40 operates as follows. That is, when hydraulic pressure is output to the oil passage 75,
The overrun clutch control valve 40 is in the upper half position, and hydraulic pressure is supplied to the overrun clutch 24. Therefore, the overrun clutch 24 is engaged, and the engine brake can be used in the first to third speeds. On the other hand, when the oil pressure in the oil passage 75 reaches 0, the overrun clutch control valve 40 is in the lower half position, and no oil pressure is supplied to the overrun clutch 24. Therefore, overrun clutch 24
is in a released state and engine braking is not available.

As described above, even in this third embodiment, when the oil pressure in the oil passage 120 becomes zero due to a failure of the solenoid valve 56, etc., the second speed state is established, and the same effect as in the first embodiment can be obtained.

In all of the above embodiments, when the solenoid valve is de-energized, the opening is opened and the output oil pressure is zero.
However, the present invention can also be applied to a device that closes the opening in a non-energized state and makes the output oil pressure the highest value. In this case, the shift valve may be configured to realize an intermediate gear such as second gear when the output oil pressure is at its highest value.

(g) As described in detail, according to the present invention, when the solenoid valve is de-energized, an intermediate gear other than the first gear and the highest gear is set; Even if a failure occurs while the vehicle is running, the vehicle will not become uncontrollable, and the vehicle can continue to run to the extent that it does not interfere with other vehicles.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the first embodiment of the present invention, Fig. 2 is a skeleton diagram of the automatic transmission, Fig. 3 is a diagram showing the hydraulic characteristics of the first embodiment, and the fourth section is a diagram showing the second embodiment of the present invention. Figure 1 shows an embodiment, Figure 5 is a diagram showing hydraulic characteristics of the second embodiment, Figure 6 is a skeleton diagram of the automatic transmission of the third embodiment, and Figure 7 is a diagram showing each shift of the third embodiment. FIG. 8 is a diagram showing a hydraulic circuit of the third embodiment, and FIG. 9 is a diagram showing hydraulic characteristics of the third embodiment. 10...1-2 shift valve, 26...2-3 shift valve, 56...Solenoid valve. Patent applicant: Japan Automatic Transmission Co., Ltd.

Claims (1)

[Claims] 1. The hydraulic pressure output by the solenoid valve is supplied to a plurality of shift valves so as to act as a switching signal pressure, and each corresponds to a plurality of stages of hydraulic pressure output by the solenoid valves that change stepwise. In a shift control device for an automatic transmission configured to obtain different combinations of switching positions of a plurality of shift valves, when a solenoid valve is de-energized, the shift valve is set to the first gear and the highest gear. 1. A shift control device for an automatic transmission, characterized in that it is configured to be in a state to realize an intermediate gear other than a gear. 2. The shift control device for an automatic transmission according to claim 1, wherein the output oil pressure of the solenoid valve in the de-energized state is 0, and the gear position achieved by the shift valve in this state is the second speed.