JP2840911B2 - Control device for hydraulically operated transmission for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus for a hydraulically operated transmission for a vehicle having a plurality of hydraulic engagement elements such as clutches and brakes.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Application Laid-Open No. Sho 59-175657, this type of control device reduces shock caused by sudden transmission of driving torque during in-gear operation from a neutral range to a running range. In order to achieve this, a so-called squat control, in which a high speed stage is first established, and then a downshift to a low speed stage to gradually transmit torque, is known. Further, in such a control device, an accumulator is connected in parallel with the hydraulic engagement element in order to buffer a sudden change in hydraulic pressure during supply / discharge of each hydraulic engagement element that establishes each shift speed.

[0003]

In the above arrangement, in order to prevent a delay in engagement of the low-speed stage hydraulic engagement element during downshifting from the high-speed stage to the low-speed stage, the high-speed stage hydraulic engagement is started from the point of in-gear. It is necessary to supply oil to the low-speed stage hydraulic engagement element together with the low-speed stage hydraulic engagement element, but usually the high-speed stage hydraulic engagement element is connected downstream from the low-speed stage hydraulic engagement element. There is a possibility that the hydraulic pressure of the engaging element is increased faster than the hydraulic pressure of the high-speed gear hydraulic engaging element, and the torque transmission is performed by the low-speed gear prior to the torque transmission by the high-speed gear, resulting in malfunction of the squat control. Control circuit design has become difficult. In view of the above, it is an object of the present invention to provide a control device capable of performing reliable squat control at the time of in-gear without accompanying difficulty in designing a hydraulic control circuit.

[0004]

In order to achieve the above object,
The present invention is a control device for a hydraulically operated transmission for a vehicle having a plurality of hydraulic engagement elements.
Equipped with a shift valve to control oil supply and drainage, traveling from neutral range
Set the shift valve to the specified
Period, together with the hydraulic engagement element for the lowest first gear,
Lubricating the hydraulic engagement element for the second shift speed higher than the shift speed
To maintain the second gear position to establish the second gear position
Then, the shift valve is moved to a hydraulic engagement element for the first speed.
Shift gear for establishing the first shift stage by refueling only the first shift stage
The first shift stage hydraulic switch.
An oil supply passage connected to the combined element, and a third change speed higher than the second speed.
For the third gear when downshifting from the first gear to the second gear
Through a control valve to an oil drain connected to the hydraulic engagement element
Equipped with an accumulator that can be selectively connected,
Connect the oil drain to the accumulator for a predetermined period during shifting
And the back pressure chamber of the accumulator is
Open to atmosphere through the shift valve at the gear position
That, characterized in that.

[0005]

In the above-mentioned predetermined period during the in-gear operation , the gear for the second shift stage is set.
Of the accumulator through the shift valve in the shift position.
Chamber is opened to the atmosphere, back pressure of the hydraulic accumulators is maintained at a low pressure. Therefore , the pressure increase of the first-gear-speed hydraulic engagement element is buffered in a hydraulic range lower than the hydraulic pressure that causes substantial engagement of the element by the buffering action of the hydraulic pressure change by the accumulator,
In the meantime, the hydraulic pressure of the second-gear-speed hydraulic engagement element is raised to a value that causes the engagement of the element, and torque transmission by the second-gear gear is performed first. Further, the accumulator is provided with a third variable.
For the third shift stage when downshifting from the first shift stage to the second shift stage
An accumulator that buffers sudden pressure drop of the hydraulic engagement element
Still works. And during this downshift,
Accu via the shift valve in the second shift position
The back pressure chamber of the accumulator is opened to the atmosphere and the back of the accumulator
The pressure is kept low. Therefore, the third shift stage hydraulic system
Combination element pressure drop is buffered in relatively low hydraulic range
As a result, the engine blows up
Unshift is performed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral 1 denotes a transmission for performing four forward speeds and one reverse speed, and an input shaft 1 connected to an engine 2 via a fluid torque converter 3 having a clutch 3a.
a between the first and fourth forward speeds G and the output shaft 1b connected to the driving wheels 4 of the vehicle via the differential gear 5 via the differential gear 5.
1, G2, G3, G4 and the reverse gear GR are arranged side by side, and the first to fourth gear hydraulic clutches C1, C2, C3, C4, which are hydraulic engagement elements, are interposed at each forward gear. The forward gears are selectively established by engagement of the hydraulic clutches, and the reverse gear GR shares the fourth gear G4 and the fourth gear hydraulic clutch C4, and the fourth gear G4
And a reverse gear GR provided on the output shaft 1b.
In the drawing of FIG. 7, the switching between the left forward position and the right reverse position is selectively established.

In addition, a one-way clutch 7 for allowing the output side to be over-rotated is provided at the first speed stage G1 so that each of the second to fourth speed hydraulic clutches C2, C3 can be engaged while the first speed hydraulic clutch C1 is engaged. , C4 are engaged to establish the second to fourth speed stages G2, G3, G4, and a first-speed hold hydraulic clutch CH that bypasses the one-way clutch 7 is provided. In some cases, the first speed G1 is established in a state where overspeed on the output side is not allowed, that is, in a state where engine braking can be applied.

[0008] Then, ₁ and the engine sensor 8 for detecting the throttle opening of the engine 2, rotational speed, cooling water temperature,
And a vehicle speed sensor ₈₂ for detecting a vehicle speed based on the rotational speed of the differential gear 5, rotation sensors 8 ₃ for detecting the rotational speed of each of the input shaft 1a of the transmission 1 and the output shaft 1b, 8 ₄ and, later described manual an electronic control circuit 9 composed of a microcomputer for inputting a signal from the position sensor 8 ₅ of the valve, and a hydraulic control circuit 10 for the plurality of hydraulic clutches provided,
The electronic control circuit 9 controls a plurality of solenoid valves, which will be described later, of the hydraulic control circuit 10 to perform a shift.

As shown in FIGS. 2 and 3, the hydraulic control circuit 10 includes a hydraulic power source 11, a parking "P", a reverse "R", a neutral "N", and an automatic transmission "D". "
, "S", "2" for holding second speed, "L" for holding first speed, manual valve 12 switchable to seven positions, and first to third three shift valves 13, 14, 15 And a forward / backward switching servo valve 16 to which a shift fork 6a of the selector gear 6 is connected.

At the "D" position of the manual valve 12, the first oil passage L1 connected to the hydraulic pressure source 11 is connected to the second oil passage L2 connected to the first-speed hydraulic clutch C1 via the annular groove 12a of the valve 12. Then, the pressure oil adjusted to a constant line pressure by the regulator valve 17 is constantly supplied to the first-speed hydraulic clutch C1 from the first oil passage L1 via the second oil passage L2, and further, from the second oil passage L2. The branched third oil passage L3 and the shift valve 1
The second, fourth, and fourth hydraulic clutches C2, C3, and C4 are selectively supplied with oil through the third, third, and fifth gears.

Here, the first shift valve 13 is urged leftward by a spring 13a, and the second shift valve 14 and the third shift valve 1 are moved.
5 is biased rightward by springs 14a and 15a, respectively.
First modulator pressure from the modulator valve 18 connected to the oil passage L1 (the lower line pressure constant pressure), the fifth oil passage communicating through the orifice 19 ₁ to No. 4 oil passage L4 on the output side of the valve 18 L5 and inputs to the right end oil chamber 15b of the left end oil chamber 13b and the third shift valve 15 of the first shift valve 13 via the sixth oil passage communicating through the orifice 19 ₂ to No. 4 oil passage L4 A normally closed type in which the oil is input to an oil chamber 13c at the right end of the first shift valve 13 and an oil chamber 14b at the right end of the second shift valve 14 via L6, and further, the air is opened to the fifth oil passage L5. of the first electromagnetic valve 20 _1, this to No. 6 oil passage L6 is disposed and a second solenoid valve 20 ₂ of the normally closed to the atmosphere opening, they shift the opening and closing of both said solenoid valves 20 _1, 20 ₂ The valves 13, 14, and 15 are switched as follows in accordance with each shift speed.

Namely, when the first speed, the first solenoid valve 20 ₁ closed and No. 2 solenoid valve 20 ₂ is opened, the left end oil chamber 13b and the third shift of the first shift valve 13 according to this Valve 1
The modulator pressure is input to the right end oil chamber 15b of the first shift valve 13 and the right end oil chamber 13c of the first shift valve 13 is connected to the second oil chamber 13b.
The oil chamber 14b at the right end of the shift valve 14 is opened to the atmosphere, the first shift valve 13 and the second shift valve 14 are in the right position,
The shift valve 15 switches to the left position. In this state, 2
A seventh oil passage L7 connected to the high-speed hydraulic clutch C2 is connected to an eighth oil passage L8 reaching the first shift valve 13 via the annular groove 14c of the second shift valve 14, and the eighth oil passage L8 is connected to a manual valve. 12 at the "D" position, the atmosphere opening groove 12b of the valve 12
To the ninth oil passage L9, which is connected via the annular groove 13d of the first shift valve 13, to drain the oil from the second-speed hydraulic clutch C2 and to the tenth oil passage L3 connected to the third-speed hydraulic clutch C3. The oil passage L10 is connected to the oil discharge passage LD via the annular groove 15c of the third shift valve 15, and the third speed hydraulic clutch C3
And the eleventh oil passage L11 connected to the fourth-speed hydraulic clutch C4 is connected to the annular groove 15 of the third shift valve 15.
12d, the twelfth oil passage L12 is connected to the third shift valve 15 via the annular groove 14d of the second shift valve 14. The thirteenth oil passage L13 is connected to an oil passage L13.
The shift valve 15 is connected to an oil drain port 15g of the shift valve 15 through an annular groove 15e, and oil is drained from the fourth-speed hydraulic clutch C4. Thus, only the first speed hydraulic clutch C1 is refueled, and the first speed stage G1 is established.

[0013] During the second speed, as to open both the first solenoid valve 20 ₁ and the second solenoid valve 20 _2, according to this first shift valve 13 is the left position, the second shift valve 14 second The three-shift valve 15 is switched to the right position. In this state, the third oil passage L3 is connected to the eighth shift valve 13 via the annular groove 13d of the first shift valve 13.
While being connected to the oil passage L8, the eighth oil passage L8 is connected to the seventh oil passage L7 via the annular groove 14c of the second shift valve 14, and is supplied to the second speed hydraulic clutch C2. The tenth oil passage L10 connected to the high-speed hydraulic clutch C3 includes the annular groove 15c of the third shift valve 15, the twelfth oil passage L12, the annular groove 14d of the second shift valve 14, the thirteenth oil passage L13, and the third shift valve 15. The oil is discharged from the third-speed hydraulic clutch C3 by being connected to the oil drain path LD through the path of the annular groove 15e.
The eleventh oil passage L11 connected to the fourth speed hydraulic clutch C4 is the third oil passage L11.
The shift valve 15 is connected to the oil drain port 15h of the shift valve 15 via the annular groove 15d to drain oil from the fourth-speed hydraulic clutch C4, thereby establishing the second-speed stage G2.

[0014] During the third speed, the first solenoid valve 20 ₁ is opened, the second
The solenoid valve 20 ₂ in which the closed, first shift valve 13 is the left position, according to this, the third shift valve 15 is held in the right position, the second shift valve 14 is an oil chamber 14b of the right end thereof Is switched to the left position by the input of the modulator pressure to. In this state, the annular groove 13d of the first shift valve 13 is the same as in the case of the second speed.
The eighth oil passage L8 connected to the third oil passage L3 via
The twelfth oil passage L12 is formed through the annular groove 14d of the shift valve 14.
Here, the twelfth oil passage L12 is connected to the tenth oil passage L10 via the annular groove 15c of the third shift valve 15 as in the case of the second speed, so that the third speed hydraulic clutch C3 is supplied with oil. On the other hand, the seventh oil passage L7 connected to the second-speed hydraulic clutch C2 is formed by the annular groove 14c of the second shift valve 14 and the thirteenth oil passage L.
13, the oil is discharged from the second speed hydraulic clutch C2 through the path of the annular groove 15e of the third shift valve 15, and the eleventh oil passage L11 connected to the fourth speed hydraulic clutch C4. Is the annular groove 1 of the third shift valve 15 as in the case of the second speed.
The oil is drained from the fourth speed hydraulic clutch C4 by being connected to the oil drain port 15h of the valve 15 via 5d, and the third speed G3 is established.

[0015] In the fourth speed, in which the closed together first solenoid valve 20 ₁ and the second solenoid valve 20 _2, modulator pressure to the left end oil chamber 13b of No. 1 shift valve 13 is inputted according to this However, the pressing force to the right due to this is the oil chamber 13 at the right end.
In balance with the modulator pressure input to c, the first shift valve 13 is held at the left position by the force of the spring 13a, and the second shift valve 14 is also held at the left position as in the case of the third speed.
On the other hand, the third shift valve 15 is switched to the left position by the input of the modulator pressure to the right oil chamber 15b. In this state,
The twelfth oil passage connected to the third oil passage L3 via the eighth oil passage L8
The oil passage L12 is connected to the eleventh oil passage L11 via the annular groove 15d of the third shift valve 15, and the fourth speed hydraulic clutch C4
To the first gear connected to the third-speed hydraulic clutch C3.
The oil passage L10 is connected to the oil passage LD via the annular groove 15c of the third shift valve 15, the oil is discharged from the third-speed hydraulic clutch C3, and the seventh oil passage connected to the second-speed hydraulic clutch C2. A thirteenth oil passage L13 connected to the oil passage L7 through the annular groove 14c of the second shift valve 14 in the same manner as in the case of the third speed is connected to an oil discharge port of the third shift valve 15 through an annular groove 15e. 15g, oil is drained from the second-speed hydraulic clutch C2, and the fourth-speed stage G4 is established.

[0016] The first of each gear speed second both solenoid valves 20 _1, 20 ₂ of the opening and closing the first to third shift valve 1
The following table summarizes the switching positions of 3, 14, and 15, and when the manual valve 12 is in the "D" position, the electronic control circuit 9 sets the two electromagnetic positions according to the predetermined shift characteristics set based on the vehicle speed and the throttle opening. The valves 20 ₁ and 20 ₂ are controlled to open and close to perform first- to fourth-speed automatic shifting.

[0017]

[Table 1]

An accumulator 21 is connected to a second oil passage L2 connected to the first-speed hydraulic clutch C1 via a fourteenth oil passage L14 branched from the second oil passage L2.
The oil passage L14 is provided with a control valve 22 that can be switched between a left position for communicating the upstream portion and the downstream portion thereof and a right position for interrupting the communication. And a downstream portion of a fourteenth oil passage L14 connected to the accumulator 21 at a position to the right of the control valve 22 is connected to an oil discharge passage L.
D, and at the left position of the control valve 22, the oil drain path LD is connected to the oil drain port 22 a of the valve 22.

The control valve 22 is urged to the left by a spring 22b, further, to the control valve 22, communicating through an orifice 19 ₃ modulator pressure from the modulator valve 18 described above in the fourth oil passage L4 An orifice 1 is provided between the left end oil chamber 22c input through the fifteenth oil passage L15 and the fourth oil passage L4.
9 ₄ and the 16 through the oil passage L16 is provided a right end oil chamber 22d to enter the third solenoid valve 20 ₃ normally closed to it to No. 15 oil passage L15 is opened to the atmosphere continuing through the 16th A normally-closed fourth solenoid valve 20 ₄ that opens the oil passage L16 to the atmosphere.
Disposed the door, when closing the third solenoid valve 20 _3, switches to the control valve 22 at the input of the modulator pressure to the left end oil chamber 22c is in the right position, also closes the third solenoid valve 20 ₃ if even occasionally close the fourth solenoid valve 20 _4, modulator pressure is inputted to the right end oil chamber 22 d, the left and right hydraulic 22c, 22 d
Of the modulator pressure, the control valve 22 is switched to the left position by the force of the spring 22b.

Here, draining from the disengaged hydraulic clutch through the drainage path LD during shifting is performed during an upshift from the second speed to the third speed and an upshift from the third speed to the fourth speed. Hour, downshift from 3rd to 2nd, 1st from 3rd
Except during the downshift from the third speed to the first speed in which the one-way clutch 7 operates, the control valve 22 is switched to the right position until the predetermined time of the shift transition period. Is connected to the oil discharge passage LD, the accumulated oil in the accumulator 21 is supplied to the oil discharge passage LD, and the pressure drop of the release-side hydraulic clutch is buffered. Then, the control valve 22 is switched to the left position to switch the oil discharge passage LD The oil drain port 2
2a so that the oil from the hydraulic clutch on the release side can be discharged from the oil discharge port 22a in addition to the oil discharge port LDa with orifice of the oil discharge path LD, and the pressure drop characteristics of the hydraulic clutch on the release side can be adjusted. To ensure proper co-meshing with the hydraulic clutch on the engagement side.

The hydraulic pressure supplied to the hydraulic clutch on the engagement side can be regulated by a pressure regulating valve 23 provided in the third oil passage L3, and the pressure regulating valve 23 is controlled by the electronic control circuit 9. Hydraulic control valve 24 consisting of a linear solenoid valve
The hydraulic pressure output from the clutch is input through a seventeenth oil passage L17, and the pressure control characteristic of the hydraulic clutch on the engagement side is controlled by the hydraulic pressure control valve 24 via the pressure regulating valve 23 during gear shifting.

At the "D" position of the manual valve 12, an eighteenth oil passage L18 is connected to the first oil passage L1 via an annular groove 12a of the valve 12, and the eighteenth oil passage L18 will be described later in detail. Nineteenth oil passage L1 connected via servo control valve 25
9 is connected to the twentieth oil passage L20 connected to the back pressure chamber of the accumulator 21 via the annular groove 14e of the second shift valve 14 located at the left position at the third speed and the fourth speed, and is connected to the back pressure chamber of the accumulator 21. The internal pressure becomes the line pressure. On the other hand, at the second speed, the twentieth oil passage L20 is connected to the twenty-first oil passage L21 extending to the first shift valve 13 via the annular groove 14e of the valve 14 by switching the second shift valve 14 to the right position. The 21st oil passage L21 is connected to the oil discharge port 13f of the first shift valve 13 through the annular groove 13e of the first shift valve 13 located at the left position, so that the internal pressure of the back pressure chamber of the accumulator 21 becomes atmospheric pressure. become.

Thus, at the time of the upshift from the second speed to the third speed, the release-side second speed hydraulic clutch C connected to the oil discharge passage LD is provided.
The pressure drop of the second-speed hydraulic clutch C3 on the release side connected to the oil discharge passage LD during the up-shift from the third speed to the fourth speed is performed in a relatively high hydraulic pressure region because the back pressure of the accumulator 21 is high. When the hydraulic pressure of the engagement-side hydraulic clutch rises, the hydraulic clutches of the disengagement side and the engagement side co-engage with each other.

At the time of the downshift from the third speed to the second speed, the back pressure of the accumulator 21 becomes low, so that the pressure drop of the disengaged third speed hydraulic clutch C3 is buffered in a relatively low hydraulic range, and as a result, the engine is operated. Smooth shifting is performed with a moderately rising speed. Then, the control valve 22 is switched to the left position when a predetermined time has elapsed from the time when the shift command was output.

The switching command to the right position of the control valve 22 is carried out by outputting the command signal for closing the third solenoid valve 20 ₃ and a command signal for opening the fourth solenoid valve 20 _4.
The third solenoid valve 20 _3, controls the clutch 3a for the fluid torque converter 3 oil supplied from the regulator valve 17 via No. 22 oil passage L22 as a hydraulic oil,
Are shared to the solenoid valve for switching the shift valve 27 provided in the conventional clutch hydraulic control circuit 26, switching the shift valve 27 according to the third closing of the solenoid valve 20 ₃ is the clutch release position of the left Can be Therefore, at the time of the above-mentioned gear shifting in which the control valve 22 is switched to the right position, the clutch 3a is disengaged and the occurrence of the gear shifting shock due to slippage in the fluid torque converter 3 is more effectively suppressed. In this case, it is better to release the clutch 3a until the shift is completed.
Therefore, in the present embodiment, as described above, the third solenoid valve 20 ₃
The even it remains closed the fourth solenoid valve 20 control valve 2 in the _fourth closed
2 can be switched to the left position. The fourth
Solenoid valve 20 ₄ is also used in an electromagnetic valve for controlling the control valve 28 and a timing valve 29 for the engaging force adjustment of the clutch 3a provided to the clutch hydraulic control circuit 26.

At the clutch release position of the shift valve 27, the branch passage L19a of the nineteenth oil passage L19 is connected to the twenty-third oil passage L23 leading to the control valve 22, and the control valve 22 is switched to the left position. The line pressure is input from the 23rd oil passage L23 to the pressure adjusting valve 23 via the 24th oil passage L24, and the output oil pressure of the pressure adjusting valve 23, that is, the oil pressure of the engagement side hydraulic clutch becomes the oil pressure of the release side hydraulic clutch. It is configured to be boosted in accordance with the decrease.

In order to reduce the in-gear shock,
At the time of in-gear operation in which the manual valve 12 is switched from the "P" or "N" position to the "D" position to start the vehicle, the first shift valve 13 is set to the left position, and the second shift valve 14 is set to the right position to temporarily set the second gear G.
2 is established, the first shift valve 13 is switched to the right position to perform the squat control for establishing the first speed stage G1. At this time, the hydraulic pressure of the first speed hydraulic clutch C1 is changed to the second speed hydraulic clutch C
It is necessary to prevent the oil pressure from rising earlier than the second oil pressure. Therefore, a small-diameter orifice 30 is provided in the second oil passage L2 at a position downstream of the branch of the third oil passage L3.
Further, a pair of side paths L2a and L2b that bypass the orifice 30 are provided in the second oil path L2, and one of the first side paths L2
Check valve 3 that allows oil supply from upstream to downstream
1 and a check valve 32 permitting oil discharge from the downstream side to the upstream side in the second side path L2b.
2a and L2b are selectively opened through the annular groove 13g of the first shift valve 13 by switching the first shift valve 13.
Then, until the first shift valve 13 is switched from the left position to the right position by the squat control and downshifted from the second speed to the first speed, the first speed hydraulic clutch C1 is gently lubricated only through the orifice 30 and the downshift is performed. When the shift is performed, the first bypass L2a is opened, and the oil pressure of the first-speed hydraulic clutch C1 is quickly raised by refueling via the bypass L2a.

In the second gear, the back pressure of the accumulator 21 is low as described above.
FIG. 4 shows a low pressure range in which an increase in the hydraulic pressure (first speed pressure) of the first speed hydraulic clutch C1 does not cause substantial engagement of the clutch C1 at high speed.
During this time, the hydraulic pressure (second speed pressure) of the second speed hydraulic clutch C2 is sufficiently increased, and the torque transmission by the second speed stage G2 is reliably performed prior to the torque transmission by the first speed stage G1. Then, at a predetermined downshift time point t1 after the in-gear time point t0, when downshifting from second gear to first gear is performed, the state is changed to a state in which torque transmission is performed by the first gear G1 by increasing the first gear pressure and decreasing the second gear pressure. Be replaced. The downshift time point t1 may be determined based on the time from the in-gear time point t0. However, the output shaft torque of the transmission, the engine speed, and the input shaft rotation of the transmission that change due to the torque transmission of the second speed G2. It may be determined based on parameters such as numbers,
Further, the engagement state of the second speed hydraulic clutch C2 is changed to the second speed pressure or the second speed hydraulic clutch C2.
The downshift time point t1 may be determined based on the slip ratio determined from the relationship between the input shaft of the high-speed hydraulic clutch C2 and the rotational speed on the output side, and based on this engagement state.

At the time of the first speed, the 21st oil passage L connected to the 20th oil passage L20 connected to the back pressure chamber of the accumulator 21 via the annular groove 14e of the second shift valve 14 located at the right position.
21 is the annular groove 13 of the first shift valve 13 located at the right position.
e to the third oil passage L3, so that the back pressure of the accumulator 21 can be controlled by the hydraulic control valve 24 via the pressure regulating valve 23, after the downshift from the second speed to the first speed. The step-up characteristic of the first-speed hydraulic clutch C1 can be appropriately controlled so as not to cause an in-gear shock.

The second bypass L2b has a function of controlling the pressure-lowering characteristic of the first-speed hydraulic clutch C1 when the position is switched from the "D" position to the "N" position, the details of which will be described later.

The oil passage configuration at the "D" position of the manual valve 12 has been described above.
The oil passage configuration is the same as the position, and the first to fourth speed automatic shifts are performed according to the shift characteristics different from the shift characteristics at the “D” position.

At the "2" position of the manual valve 12, the first oil passage L1 is connected to the second oil passage L2 via the annular groove 12a of the valve 12.
To the ninth oil passage L9 via the annular groove 12a, the communication passage 12c, and the annular groove 12d, and the line pressure is input to the first shift valve 13 via the ninth oil passage L9. At the same time, the output oil pressure of the pressure regulating valve 23 is input via the third oil passage L3. The eighth shift valve reaching the second shift valve 14
The ninth oil passage L9 is connected to the oil passage L8 via the annular groove 13d of the first shift valve 13 at the right position of the valve 13 and the third oil passage L3 at the left position of the first shift valve 13. To the right position, and connects the eighth oil passage L8 with the seventh oil passage L8 through the annular groove 14c of the valve 14.
By connecting to the oil passage L7, the second-speed hydraulic clutch C2 is supplied with oil regardless of whether the first shift valve 13 is located at the left or right position, and the second-speed stage G2 is established. If the vehicle is switched to the "2" position during high-speed driving and suddenly downshifts to the second speed, an engine overrun or a large shift shock may occur. Switch the second shift valve 14 to the left position,
The eighth oil passage L8 is connected to the twelfth through the annular groove 14d of the valve 14.
The third shift stage G3 is established by connecting the third speed hydraulic clutch C3 via the third shift valve 15 to the third speed stage G3, and the second shift valve 14 is shifted to the right position when the speed is reduced to a predetermined vehicle speed or less. Switch to downshift to 2nd gear. The third shift valve 15 has a twenty-fifth oil passage L2 extending from the servo control valve 25.
5 is provided with a left end oil chamber 15i for connecting
The ninth oil passage L9 is connected to the fifth oil passage L25 via the shuttle valve 33, and at the "2" position, the ninth oil passage L9 to the 25th oil passage L
The line pressure is input to the oil chamber 15i through the oil pressure chamber 25, and the third shift valve 15 is connected to the third speed hydraulic clutch C3.
The oil passage L10 and the twelfth oil passage L12 are connected to the annular groove 1 of the valve 15.
5c, which is connected to the right third speed position
The third shift valve 15 is also the solenoid valve 20 ₁ is closed in the left 4
It does not switch to the fast position.

At the "L" position of the manual valve 12, the first oil passage L1 is connected to the second oil passage L2 via the annular groove 12a of the valve 12.
And the oil chamber 1 at the left end of the second shift valve 14 through the annular groove 12a, the communication passage 12c, and the annular groove 12d.
4f, the second shift valve 14 is constrained to the second speed position on the right, and the 27th oil passage L27 extending from the first shift valve 13 is connected to the manual valve 12.
1st-speed hold hydraulic clutch CH through the annular groove 12e of
Is connected to a twenty-eighth oil passage L28. And the first
When the shift valve 13 is switched to the right position, the third oil passage L3 is connected to the twenty-seventh oil passage L27 via the annular groove 13e of the valve 13, and is supplied to the first-speed hold hydraulic clutch CH.
First gear G1 is established in a state where the engine brake can be applied. When the speed is switched to "L" at a speed equal to or higher than the predetermined vehicle speed, the first shift valve 13 is switched to the left position, the third oil passage L3 is connected to the eighth oil passage L8, and the position is shifted to the right second speed position. The second-speed hydraulic clutch C2 is supplied with oil via the restricted second shift valve 14 to establish the second-speed stage G2, and when the vehicle is decelerated to a predetermined vehicle speed or less, the first shift valve 13 is switched to the right position to switch to the first-speed position. Downshift to

At the "R" position of the manual valve 12, the first oil passage L1 is connected to the 29th oil passage L29 extending to the first shift valve 13 through the annular groove 12a of the valve 12, and the fourth speed hydraulic pressure A branch passage L11a branched from the eleventh oil passage L11 connected to the clutch C4 via the shuttle valve 34 is connected to a thirtieth oil passage L30 extending from the second shift valve 14 via an annular groove 12e of the manual valve 12. In the "R" position, the first shift valve 13 is switched to the left position. According to this, the 29th oil passage L29 is connected to the left end oil chamber 16a of the servo valve 16 through the annular groove 13h of the valve 13. The 31st
The servo valve 16 is moved to the right by the line pressure input through the oil passage L31, the selector gear 6 is switched to the right reverse position, and the 31st oil passage L31 is connected to the reverse position. The third reaches the second shift valve 14 through the shaft hole 16b of the servo valve 16 opening to the oil chamber 16a.
2 oil passage L32, which is connected to the second shift valve 1
4 and is connected to the thirtieth oil passage L30. The oil is supplied to the fourth-speed hydraulic clutch C4 via the branch passage L11a, and the reverse gear GR is established. The downstream side of the 32nd oil passage L32 is branched into two branch passages L32a and L32b.
The hydraulic pressure of the branch passage L32b can be adjusted by the pressure regulating valve 23, and the thirtieth oil passage L30 is connected to the branch passage L32a at its left position through the annular groove 14g of the second shift valve 14,
It is selectively connected to the branch passage L32b at the right position so that the line pressure and the output pressure of the pressure regulating valve 23 can be selected as the operating pressure of the fourth speed hydraulic clutch C4.

Move the manual valve 9 from the "R" position to the "D" position.
When switching to the forward traveling position of "S", "2" or "L",
The line pressure is adjusted to the eighteenth oil passage L18, the servo control valve 25, and the first
The oil chamber 16c on the right side of the servo valve 16 via the 9 oil passage 19
To move the selector valve 6 to the left forward position by moving the servo valve 16 to the left. In this case, when the drive wheel is switched from the "R" position to the forward running position in a slipping state, the selector gear 6 moves leftward from the reverse position and moves forward while the output shaft 1c is inertially rotating in the reverse direction. Switching to the position may not be performed smoothly. Therefore, the hydraulic pressure of the first-speed hydraulic clutch C1 is applied to the right end of the servo control valve 25 via the branch passage L2c of the second hydraulic passage L2, and the hydraulic pressure of the first-speed hydraulic clutch C1 rises to a certain extent and the clutch C
When the reverse rotation of the output shaft 1c is braked by the engaging force of No. 1, the servo control valve 25 moves leftward against the spring 25a to connect the eighteenth oil passage L18 to the nineteenth oil passage L19, and the servo valve 16 Was moved to the left. Also, the servo control valve 2
The hydraulic pressure of the 31st oil passage L31 is applied to the left end of No. 5 so that the servo control valve 25 is reliably returned to the right position during reverse travel. Further, at the reverse position of the servo valve 16, a 33rd oil passage L33 communicating with the oil chamber 16c on the right side of the valve 16 via the cutout groove 16d of the valve 16 is provided.
The 25th oil passage L25 connected to the oil chamber 15i at the left end of 5 is connected to the 18th oil passage L18 at the right position of the servo control valve 25 and the 33rd oil passage L33 at the left position of the valve 25. I did it. According to this, from the “R” position to the “D”
When the servo control valve 25 is switched to the "S" position, the servo control valve 25 is restricted to the right position, or even when the servo control valve 25 is switched to the left position, the servo valve 16 is restricted to the reverse position, and the selector gear 6 Is not switched to the forward position, the 18th oil passage L18 or the 33rd oil passage L33 to the 25th oil passage L25
, The line pressure is input to the oil chamber 15i at the left end of the third shift valve 15, the third shift valve 15 is restrained at the right third speed position, and it becomes impossible to supply oil to the fourth speed hydraulic clutch C4,
The establishment of the reverse gear GR at the "D" and "S" positions is prevented.

At the "N" position of the manual valve 12, the communication between the first oil passage L1 and the other oil passages is cut off. by the way,
When the vehicle is stopped in the “D” position, the first gear G1
The drive unit composed of the engine and the transmission is displaced in attitude while elastically deforming the engine mount by the driving reaction force due to the power transmission via the power transmission, and at this time, when the manual valve 12 is switched to the “N” position to be in the neutral state, The displaced drive unit returns to the steady position, and the shock (off-gear shock) at this time becomes a problem. "N"
In the position, the second oil passage L2 is connected to the annular groove 12 of the manual valve 12.
d to the atmosphere via the communication passage 12c and the oil is discharged from the first-speed hydraulic clutch C1.
If the hydraulic pressure of the first-speed hydraulic clutch C1 is gently lowered by restricting the drainage by the second orifice 30, the above-mentioned off-gear shock due to rapid release of the driving force can be prevented.
However, if the viscosity of the oil is high at a low temperature, the release of the first-speed hydraulic clutch C1 is too slow if the oil discharge is restricted by the orifice 30, and the clutch C1 is dragged, which adversely affects durability. In this case, if the first shift valve 13 is switched to the left position, the above-mentioned second bypass L2b is opened, the oil is bypassed through the orifice 30, and the excessive release delay of the first-speed hydraulic clutch C1 is caused. No problems occur.

In the "N" position, the power supply to the solenoid valve is normally stopped in order to save power.
When the solenoid valves 20 ₁ and 20 ₂ are closed, the first shift valve 13 is switched to the left position. However, when off-gear shock becomes a problem, the first shift valve 13 is switched for a predetermined time from the point of switching from “D” to “N”. The first shift valve 13 is held at the right position, the second bypass L2b is shut off, and the orifice 30 controls the drainage.

At the "P" position of the manual valve 12, the first oil passage L1 is connected to the 29th oil passage L29 in the same manner as the "R" position, and the servo is operated by inputting the line pressure via the 31st oil passage L31. Although the valve 16 is switched to the reverse position, at the "P" position, the thirtieth oil passage L30 is not connected to the branch passage L11a, and the reverse gear GR is not established.

[0039]

As is apparent from the above description, according to the present invention, the pressure increase of the first speed-stage hydraulic engagement element at the beginning of the in-gear is buffered in the low-pressure range by the accumulator, and the second speed-stage is interposed therebetween . The hydraulic pressure of the hydraulic pressure engagement element can be sufficiently increased, and the torque transmission by the second gear can be reliably performed prior to the torque transmission by the first gear , thereby improving the reliability of the squat control. easier it is to design the hydraulic control circuit Te, further, Dow from the third gear position to the second gear position
3rd gear shift by common accumulator even during gear shift
Reduces the pressure drop of the stage hydraulic engagement element in the low pressure range,
So that you can make a smooth downshift
The back pressure of the accumulator is controlled by a shift valve
This eliminates the need for a special pressure regulating valve for back pressure control,
Simultaneous use of accumulator and simplification of hydraulic control circuit
Can be achieved.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a transmission to which the present invention is applied and a control system thereof.

FIG. 2 is a circuit diagram showing the hydraulic control circuit;

FIG. 3 is an enlarged view of a manual valve and a shift valve in the circuit of FIG. 2;

FIG. 4 is a graph showing changes in hydraulic pressure of a first-speed hydraulic clutch and a second-speed hydraulic clutch during in-gear.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transmission C1 1st-speed hydraulic clutch (hydraulic engagement element for 1st speed ) C2 2nd-speed hydraulic clutch (hydraulic engagement element for 2nd speed ) C3 3rd-speed hydraulic clutch (hydraulic engagement element for 3rd speed ) ) G1 1 speed (first speed stage) G2 2 speed (second
Lubrication gear) G3 3 speed (third gear) 9 electronic control circuit 10 the hydraulic control circuit 13, 14 and 15 shift valve 21 accumulator 22 control valve L2 second oil passage (hydraulic engaging element for the first speed stage Road) LD oil drain

Continuation of the front page (72) Inventor Naoto Ono 1-4-1 Chuo, Wako-shi, Saitama Prefecture Honda R & D Co., Ltd. (56) References JP-A-3-199763 (JP, A) (58) Fields investigated (Int.Cl. ⁶ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (1)

(57) [Claims] 1. A control apparatus for a hydraulically operated vehicular transmission having a plurality of hydraulic engaging elements, these hydraulic engaging elements
Equipped with a shift valve to control oil supply and drain from the neutral range
At the time of in-gear operation by operating to the travel range,
For a predetermined period of time, together with the hydraulic engagement element for the first speed at the lowest speed
Supply the hydraulic engagement element for the second speed, which is higher than the first speed.
To the second gear position to establish the second gear position
Hold, and then shift valve is engaged with hydraulic pressure for first gear
For the first shift stage that establishes the first shift stage by refueling only the elements
In a gear for switching to a shift position, an oil supply passage connected to a hydraulic engagement element for a first speed change step;
Downshift from the third speed to the second speed, which is higher than the speed
Drainage connected to the third speed hydraulic engagement element during the shift
Accumulator that can be selectively connected to the road via a control valve
The oil discharge passage for a predetermined period during the downshift.
Connected to the accumulator and shift the back pressure chamber of the accumulator.
Through the shift valve at the second shift position of the shift valve.
To air opening, the control apparatus for a hydraulically operated vehicle transmission, characterized in that.