JPH01199043A - Speed change control device for automatic transmission - Google Patents

Abstract

PURPOSE:To enhance the reliability of speed change control by controlling changing-over of a 3-4 shift valve and an over-run clutch control valve using a single solenoid valve, and thereby reducing the number of oil pressure output stages of a changeover solenoid valve for another shift valve. CONSTITUTION:When an electronic control device 58 changes over No.1 solenoid valve 80 from No.1 to No.2 oil pressure output condition, a 3-4 shift valve is changed over from No.1 to No.2 position, while an over-run clutch control valve 40 is held in No.1 position to be turned into No.2 position when No.3 oil pressure is put out. Accordingly the same speed change position is attained with No.2, No.3 oil pressure, but the condition of the control valve 40 is different, and engagement/disengagement of an over-run clutch 24 is selectable according to No.2 or No.3 oil pressure output in a speed change position below the m'th speed. Also the number of oil pressure output stages of the No.2 solenoid valve 56 to control changing-over of the 1-2 and 2-3 shift valves 110, 126 can be reduced. Thus the reliability of the speed change control can be enhanced.

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 makes it possible to switch between four shift valves using one solenoid valve.

On the other hand, Japanese Unexamined Patent Publication No. 62-62047 discloses a system using a total of three solenoid valves for speed change control. That is, two solenoid valves are used for switching the shift valve, and the remaining one solenoid valve controls the overrun clutch control valve. The overrun clutch control valve controls engagement and release of the overrun clutch, which switches between applying and deactivating the engine brake. As a result, between 1st and 3rd gears, it is possible to select between a state in which the engine brake is applied and a state in which it is not applied, and in 4th gear, a state in which the engine brake is always ineffective and a state in which the engine brake does not apply can be selected.
-ru.

Problem (c) The problem to be solved by the invention When the latter conventional technology is applied to the conventional technology of the present invention, the shift valve is switched by one solenoid valve, and the overrun clutch control valve is switched by one solenoid. This is done by a valve, and only two solenoid valves are required in total. However, in this case, it is necessary to control the shift between the four speeds using four or more levels of signal oil pressure generated by one solenoid valve, and the difference between the A and No. 3 oil pressures at each stage becomes small. The need for identification reduces the reliability of the switching viscosity. The purpose of the present invention is to solve such problems.The present invention has the following advantages: By controlling one shift valve and overrun clutch; ta control valve by the same solenoid valve;
Solve the above problems. That is, the shift control device for an automatic transmission according to the present invention provides a first shift in which the spool is switched between a first position and a second position corresponding to the m+1th speed and the mth speed, respectively, according to the switching signal pressure. Valve (3-4
shift valve 70) and one or more other shift valves (1-2 shift valve 110 and 2-3 shift valve 126) that change gears between the m-th and m-th gears, and the spool is moved to the By switching between the first position and the second position, the supply and discharge of hydraulic pressure to the overrun clutch (24) is controlled, and by engaging the overrun clutch in the first position, the engine brake can be applied. , an overrun clutch control valve (40) that disables the engine brake by releasing the overrun clutch in the second position, and a first shift valve and overrun clutch control valve that controls the switching signal pressure according to the applied electric power A and ζ. The first solenoid valve (80
), another solenoid valve (56) that performs switching control of the other shift valve, and an electron that provides electrical signals to the first solenoid valve and the other solenoid valve;
II control device (58), and the electronic control device outputs a first hydraulic pressure (58) having a different magnitude as a switching signal.
P, ), a second hydraulic pressure (P2), and a third hydraulic pressure (P3) can output an electric signal that adjusts at least three levels of oil pressure, and when the first oil pressure is output, the spool of the first shift valve is moved to the first oil pressure. 1 position and the spool of the overrun clutch control valve to one of the first and second positions, and when the second hydraulic pressure is output, the spool of the shift valve is set to one of the first and second positions. The spool of the overrun clutch control valve is set to the second position and the spool of the overrun clutch control valve is set to the one position, and when the third hydraulic pressure is output, the spool of the shift valve is set to the second position and the overrun clutch is controlled. The valve is sized to place the spool of the valve in the other of the first and second positions. Note that the symbols in parentheses indicate corresponding members and pressures in the embodiments described later.

(E) In action 7, when the first solenoid valve is actuated by the electrical signal from the slave control device and switches the first hydraulic output state to the second hydraulic output state, only the spool of the first shift valve shifts from the first position to the second solenoid valve. position, and the spool of the overrun clutch control valve is held in the first position (or second position). On the other hand, when the third hydraulic pressure is output, both the spools of the first shift valve and the overrun clutch control valve move to the second hydraulic pressure.
position (or the spool of the first shift valve is switched to the second position and the spool of the overrun clutch control valve is switched to the first position). Therefore, although the gear position is the same when the second hydraulic pressure is output and when the third hydraulic pressure is output, the states of the overrun clutch control valve are different.

As a result, at the m-th gear and higher gears, it is possible to select whether to engage or disengage the overrun clutch depending on whether the second hydraulic pressure or the third hydraulic pressure is output. Therefore, the first solenoid valve can be used for controlling the speed change between the (m+1)th speed and the mth speed and for controlling the overrun clutch.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5 of the accompanying drawings.

FIG. 2 is 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 shaft 12 is transmitted via the torque converter 10, and an output lllIb14 which transmits the driving force to the final drive device.
, first planetary gear set 15, second planetary gear set 16, reverse clutch 18, high clutch 20, forward clutch 22, overrun clutch 24, low and reverse brake 26, band brake 28, row one-way clutch 29, and forward one-way clutch. It has 30. Note that the torque converter 10 has a lock-up clutch 11 built therein. The first planetary gear set 15 is
Sun gear S1, internal gear R1, both gears Sl
and a carrier Pct that supports pinion gear P1 that meshes with R1 at the same time, and planetary gear set 16 that supports sun gear S2, internal gear R2, and pinion gear P2 that meshes with both gears S2 and R2 simultaneously. It is composed of a carrier PC2. The carrier PCI can be connected to the human power shaft 13 via the high clutch 20, and the sun gear S1 is connected to the reverse clutch 1.
It can be connected to the human power shaft 13 via 8. carrier PC
t can also be connected to the internal gear R2 via the forward clutch 22 and the forward one-way clutch 30 connected in series thereto, or via the overrun clutch 24 arranged in parallel to the forward clutch 22 and the forward one-way clutch 30. . Sun gear S2 is always connected to human power shaft 13, and internal gear R1 and carrier PC2 have output IIqb14.
is always connected. Low and reverse brake 2
6 can fix the carrier Pct, and the band brake 28 can fix the sun gear Sl. Row one-way clutch 29 is carrier P
C1 is arranged in an orientation that allows normal rotation (rotation in the same direction as the engine output shaft 12) but does not allow reverse rotation (rotation in the opposite direction to normal rotation).

The power transmission mechanism includes clutches 18, 20, 22 and 2.
4. By operating the brakes 26 and 28 in various combinations, the rotational state of each element (St, S2, R1, R2, pct, and PC2) of the planetary IA1 East set 15 and 16 can be changed. The rotational speed of the output shaft 14 relative to the rotational speed of the human-powered 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. 3, it is possible to change the old road from 4th gear to reverse 1st gear. Note that O marks in Fig. 3 indicate operating clutches and brakes, α1 and α2 are the ratios of the number of teeth of sun gears Sl and S2 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. 1 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 when the spool 112 is in the lower half position in the figure, the oil passage 116 and the oil passage 118 communicate with each other.
At the upper position in the figure, the oil passage 118 is drained. 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 exerted by the spring 114. Line pressure is always supplied to the oil passage 116 from the manual valve 124 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 the spool 128 connects the oil passage 118 and the oil passage 32 at the 41-L half position: ξ, and at the lower half position in the figure. Drain the oil passage 32. The state of the spool 128 is determined by the oil pressure acting on the port 34 from the oil passage 120. The oil passage 118 is connected to a dual application chamber 2A for tightening the band brake 28. Oil passage 3 in which orifice 31 is provided
2 is connected to a third-speed release chamber 3R for releasing the high clutch 20 and band brake 28.

The 3-4 shift valve 70 is composed of a spool 71 and a spring 72, and when the spool 71 is in the lower half position in the figure, the oil passage 118 and the oil passage 74 are communicated with each other. drain. The state of the spool 71 is determined by the oil pressure acting on the port 76 from the oil passage 75.

The oil passage 74 is connected to the 4th speed river apply chamber 4A, which engages the band brake 2B.

The overrun clutch control valve 40 is composed of a spool 42 and a spring 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 hydraulic pressure acting on the boat 46 from the oil passage 75. 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 50 to which constant pressure is always supplied from the pilot pressure valve 48. The oil passage 120 is provided with an opening 154, 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 120 can be adjusted to a predetermined oil pressure commanded by the electronic control device 58.

Furthermore, the aforementioned oil passage 75 is connected to an oil passage 50 to which a constant pressure is always supplied from the pilot pressure valve 48 and an orifice 78.
connected via. The oil passage 75 is provided with an opening 179, and a solenoid valve 80 that can open and close the opening lower 9 is provided. The solenoid valve 80 is duty ratio controlled by a signal from the electronic control device 58. Thereby, the oil pressure in the oil passage 75 can be adjusted to a predetermined oil pressure commanded by the electronic control device 5B.

The electronic control device 58 receives electric signals from a vehicle speed sensor 60, a throttle opening sensor 62, etc.
Based on these, the electronic control unit 58 outputs a signal for adjusting the oil pressure of the oil passage 75 into three levels: p, , p, and P3. In addition, the magnitude of hydraulic pressure is P 3 > P 2 > P
+ Toshishita. On the other hand, the 3-4 shift valve 70 is in the state shown in the lower half of the figure when the oil pressure of the port 76 is higher than Pu.
It is set so that when it becomes larger than p,%, the state shown in the upper half of the figure will occur. Similarly, the overrun clutch control valve 40 is set so that when the oil pressure of the boat 46 is less than or equal to PA, it will be in the lower half of the figure, and when it is greater than PA, it will be in the upper half of the figure. The magnitude of these oil pressures is set so that PA>P8. Also, the hydraulic pressure p
,, The relationship between p2 and P3 and the hydraulic pressure PA and PR is P 3 > P A > P 2 > P a
> P + . This relationship is illustrated in FIG. 4.

Similarly, the operation of the solenoid valve 56 is controlled by a signal from the electronic control device 58, and the oil pressure of the /111 path 120 is controlled in three stages: p, , p, and p, (p, <P!, <PR). be done. In addition, 1-2 shift valves 110 and 2
The switching pressures PC and Po of the -3 shift valve 126 are set as shown in FIG.

- By setting the hydraulic characteristics like two sets, it is possible to control the speed change and the overrun clutch 24.

First, regarding gear shifting, the oil pressure in the oil passage 75 is Pl or P3.
When the oil pressure in the oil passage 120 becomes PR in state B (that is, the state in which the 3-4 shift valve 70 is in the upper half), the 1-4 shift valve 70 is in the upper half position.
Both the 2-shift valve 110 and the 2-3 shift valve 126 are in the upper half state in the figure, and the forward clutch 22
Only the first gear is engaged and the first gear is set. Next, oil path 120
When the oil pressure is set to 24, the 1-2 shift valve 110 is in the upper half state in the figure, and the 2-3 shift valve 126 is also in the lower part state. For this reason, the forward clutch 22
In addition, hydraulic pressure is also supplied to the second gear apply chamber 2A, the band brake 28 is engaged, and the automatic transmission enters the second gear state. Next, when the oil pressure of the oil passage 120 is set to 25, 1-2
The shift valve 110 is in the state shown in half F in the figure, while
-3 shift valve 126 is in the state shown in the upper half of the figure. As a result, the high clutch 20 and the 3rd gear release chamber 3R
Hydraulic pressure is supplied to the 3rd speed state. Next, oil path 7
When the oil pressure of No. 5 is set to Pl, the 3-4 shift valve 70 is switched to the upper half position. As a result, the band brake 28
Hydraulic pressure is supplied to the 4th gear Kawa Apply'L 4 A, and the 4th gear
It will be in a state of speed.

Further, the overrun clutch control valve 40 operates as follows. That is, if the oil pressure in the oil passage 75 is Pl or P3, the 3-4 shift valve 7
0 is in the third speed position, but the position of the overrun clutch control valve 40 changes between oil pressure P2 and oil pressure P3. At oil pressure P3, overrun clutch control valve 40 is in the upper half position, and oil pressure is supplied to overrun clutch 24. Therefore, the overrun clutch 24 is engaged and the first
Engine braking can be used in 3rd to 3rd speeds. On the other hand, when the oil pressure is P2, the overrun clutch control valve 40 is at the F half position, and no oil pressure is supplied to the overrun clutch 24.

Therefore, the overrun clutch 24 is in a released state and engine braking cannot be utilized.

As described above, the solenoid valve 56 controls the 1-2 gear shift and the 2-3 gear shift, and the solenoid valve 80 controls the 3-4 gear shift and the overrun clutch control valve 40.
Since the switching is controlled, both solenoid valves 56 and 80 only have to output three levels of oil pressure, respectively, and the accuracy of identifying fl+pressure is improved. In other words, for example, if one solenoid valve outputs four levels of oil pressure, the difference in oil pressure between each level will be small, and if there are large variations in the setting force of the shift valve spring, malfunction may occur. there is a possibility. Setting the oil pressure to three levels increases the pressure difference between each level, which improves reliability accordingly.

Next, another embodiment of the present invention shown in FIG. 6 will be described.

In the same figure, the overrun clutch control valve 40'' is composed of a spool 42° and a spring 44°, and when the spool 42° is in the lower half position in the figure, the oil passage 77 and the oil passage 73 communicate with each other. Above?: Oil passage 7 at the part position
7 is drained. The position of spool 42 is oil path 75
is determined by the hydraulic pressure acting on the boat 46. The oil passage 77 is connected to the overrun clutch 24, and the oil passage 73
is connected to the 3-4 shift valve 70°.

The 3-4 shift valve 70' is composed of a spool 71' and a spring 72°, and when the spool 71'' is in the upper half position in the figure, it drains the oil passage 74 and drains the oil passage 74.
3 is connected to the oil passage 116, and the oil passage 74 is connected to the oil passage 74 at the lower half position in the figure.
is connected to the oil passage 118 and the oil passage 73 is drained. Here, the relationship between the engagement/disengagement of the overrun clutch 24 and the magnitude of the oil pressure in the oil passage 46 is opposite to that in the embodiment shown in FIG. 1 above. The rest is the same as the embodiment shown in FIG. 1, so the explanation thereof will be omitted.

In this embodiment, the same operation and effect as in Fig. 1 can be obtained, and in the event of a failure in which the overrun clutch control valve 40° is stuck in the overrun clutch engagement position, the 40° Since oil pressure cannot be supplied from the -4 shift valve 70' to the oil passage 73, it is possible to prevent the automatic transmission from interlocking in the fourth gear.

It goes without saying that in the other embodiments described above, the overrun clutch control valve 40 of FIG. 1 may be used instead of the overrun clutch control valve 40°, and the other embodiments may be the same as those of FIG. 2.

(G) As described in detail, according to the present invention, one solenoid valve controls switching of one shift valve and switching of an overrun clutch control valve; The number of hydraulic output stages of the solenoid valve for switching the shift valve can be reduced, and the reliability of gear change control can be improved.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an embodiment of the present invention, Fig. 2 is a skeleton diagram of an automatic transmission, Fig. 3 is a diagram showing a combination of elements that operate at each gear stage, and Figs. 4 and 5 are diagrams of the present invention. FIG. 6, which is a diagram showing the hydraulic characteristics of the invention, is a diagram showing another embodiment of the invention. 110...1-2 shift pulp, 126...2-3
Shift valve, 40... Overrun clutch-control valve, 56... Solenoid valve, 58... Electronic control device, 70... 3-4 shift valve, 80... Solenoid valve. Patent applicant: Japan Automatic Transmission Co., Ltd.

Claims (1)

[Claims] A first shift valve in which the spool is switched between a first position and a second position corresponding to the m+1th speed and the mth speed, respectively, according to a switching signal pressure; By switching the spool between the first position and the second position using the above-mentioned separate shift valve and switching signal pressure, the supply and discharge of hydraulic pressure to the overrun clutch is controlled, and the overrun clutch is engaged in the first position. An overrun clutch control valve that enables engine braking by disengaging the engine brake and disables engine braking by releasing the overrun clutch in the second position; It has a first solenoid valve that outputs an output to the clutch control valve, another solenoid valve that performs switching control of the other shift valve, and an electronic control device that provides an electric signal to the first solenoid valve and the other solenoid valve. The electronic control device uses the first hydraulic pressure, the second hydraulic pressure, and the third hydraulic pressure, which have different magnitudes as switching signal pressures.
It is possible to output an electric signal that adjusts at least three levels of oil pressure, and when the first oil pressure is output, the spool of the shift valve is set to the first position, and the spool of the overrun clutch control valve is set to the first position and the spool of the overrun clutch control valve. When the second hydraulic pressure is output, the spool of the shift valve is set to the second position, and the spool of the overrun clutch control valve is set to the first position. When the third hydraulic pressure is output, the spool of the shift valve is set to the second position, and the spool of the overrun clutch control valve is set to the other of the first and second positions. A shift control device for an automatic transmission that is sized to the desired position.