JPH10141497A - Oil pressure controller for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform lock-up control and engagement control for a reverse clutch when a backward step is selected by one control valve. SOLUTION: When forward gear change step is selected, an oil passage 30 communicated with a lock-up clutch 16 is connected with an oil passage 24 in which regulator pressure PR adjusted by a torque converter regulator valve 25 flows through an oil passage 31 in which a solenoid valve 32 is provided in a manual valve 18 to supply operation pressure controlled by the solenoid valve 32 to the lock-up clutch 16. Moreover, when a backward step is selected, an oil passage 22 which supplies line pressure is connected with an oil passage 20 communicated with a reverse clutch 9 through an oil passage 31 in which the solenoid valve 32 is provided to supply operation pressure controlled by the solenoid valve 32 to the reverse clutch 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to lock-up control and hydraulic control for a friction engagement element when a reverse gear is selected.
The present invention relates to a hydraulic control device for an automatic transmission performed by two control valves.

[0002]

2. Description of the Related Art Generally, in this type of automatic transmission, when a driver operates a select lever from a neutral position (N range) to a reverse position (R range), a manual valve interlocked with the select lever is used. The operating pressure is supplied to the reverse clutch and the low and reverse (L & R) brake, and the reverse clutch and the L & R brake are engaged to transmit the engine output shaft to the traveling drive system via the reverse gear of the automatic transmission. And enable reverse running.

At this time, the reverse clutch and L &
When the operating pressure is suddenly applied to the R brake, a so-called select shock occurs in which the engine output is rapidly transmitted to the traveling drive system via the reverse gear.

[0004] As means for reducing this select shock, for example, Japanese Patent Application Laid-Open No. 7-269885 discloses an L & R.
A first hydraulic passage having an orifice and a second hydraulic passage not having an orifice are connected to the brake, and are supplied to the L & R brake during a transition immediately after selecting the reverse speed from the N range. Operating pressure is quickly discharged through the second hydraulic passage in which the orifice is not interposed, and when the engagement operation of the reverse clutch is started,
There is disclosed a technique for supplying the L & R brake while gradually increasing the operating pressure from a first hydraulic passage interposed with an orifice.

[0005]

However, in the above prior art, in order to reduce the select shock, when the reverse gear is selected from the N range, the operating pressure supplied for engaging the L & R brake is changed to the orifice. Second without
The hydraulic pressure is released once through the hydraulic passage, and after the reverse clutch is engaged, the operating pressure is again supplied to the L & R brake through the first hydraulic passage having an orifice. Therefore, it is difficult to reduce the select time required from when the reverse gear is selected to when the reverse operation is actually started.

In addition, two hydraulic passages, a first hydraulic passage having an orifice and a second hydraulic passage having no orifice, are denoted by L.
& R brake, it must be equipped with a switching valve for switching these two hydraulic passages, a check valve for preventing backflow, etc. In addition to the complicated hydraulic circuit, the number of parts There is an inconvenience that the production cost rises due to the increase.

On the other hand, for example, SAE Paper 890528 uses one solenoid valve and one switching valve to control the L & R brake engagement control at the first speed and the lockup control at the second speed or higher. Thus, there is disclosed a technology for reducing the number of parts by sharing a solenoid valve and a part of a hydraulic passage and simplifying a hydraulic circuit.

However, in this prior art, the switching valve which operates by using the operating pressure supplied to the second or higher speed friction engagement element operates the hydraulic passage communicating with the L & R brake and the hydraulic passage communicating with the lock-up clutch. Since the solenoid valve is selectively connected to the passage, at the first speed, the switching valve communicates the solenoid valve with the hydraulic passage on the L & R brake side and shuts off the hydraulic passage on the lock-up clutch side. At the second speed or higher, the hydraulic passage on the lock-up clutch side is connected to the solenoid valve, and the hydraulic passage connected to the L & R brake is shut off.

As a result, the lock-up control becomes impossible at the first speed, and the fuel consumption rate deteriorates. In the second and higher speeds, the hydraulic passage communicating with the L & R brake is blocked, so that, for example, when shifting from the second speed to the first speed, the lock-up clutch side is released and the L & R brake is engaged. And when the 2 & 4 brake is engaged, the operating pressure cannot be supplied to the L & R brake immediately. As a result, there is a time lag between the releasing operation of the 2 & 4 brake and the engaging operation of the L & R brake. Displacement occurs, giving the driver a sense of incongruity.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides an automatic transmission that is both inexpensive and has high control accuracy by realizing both a reduction in the required select time when selecting the reverse gear and a reduction in the select shock with a simple configuration. It is an object to provide a hydraulic control device.

[0011]

To achieve the above object, the present invention provides a hydraulic control device for an automatic transmission, comprising: a first hydraulic passage communicating with a lock-up clutch of a torque converter; A second hydraulic passage communicating with the joint element, a third hydraulic passage for supplying operating pressure provided with a control valve, and the third hydraulic passage when the forward gear is selected in conjunction with the select lever. A manual valve that is connected to the first hydraulic passage and switches and connects the third hydraulic passage to the second hydraulic passage when the reverse stage is selected.

In the present invention, when the driver operates the select lever to select a forward gear, a manual valve interlocked with the select lever locks the third hydraulic passage for supplying operating pressure, which is provided with a control valve. It is connected to a first hydraulic passage communicating with the up clutch, flows into the third hydraulic passage, and supplies the working pressure regulated by the control valve to the lock-up clutch via the first hydraulic passage. Perform lock-up control. On the other hand, when the driver operates the select lever to select the reverse gear, the third hydraulic passage is connected to the second hydraulic passage communicating with the friction engagement element for selecting the reverse gear via the manual valve. And supplying the working pressure, which flows into the third hydraulic passage and is regulated by the control valve, to the friction engagement element for selecting the reverse gear through the second hydraulic passage. Control hydraulic pressure.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a power transmission train of an automatic transmission employed in the present embodiment. In this power train,
A torque converter 1, an oil pump 2, and a multi-stage transmission 3 are provided from the input side, and a driving force from an engine output shaft 4 is transmitted to the input shaft 5 of the multi-stage transmission 3 via the torque converter 1.

The multi-stage transmission 3 includes a front planetary gear unit 6 and a rear planetary gear unit 7 disposed on the shaft of the input shaft 5, and each of the planetary gear units 6 (7) is a planetary carrier 6a (7).
a), ring gear 6b (7b), pinion gear 6c (7
c) and a sun gear 6d (7d).

A high clutch 8, a reverse clutch 9, and a reverse clutch 9 are provided beside the front planetary gear unit 6.
& 4 brakes 10 are arranged in parallel. The high clutch 8 interrupts power transmission between the input shaft 3 and the front planetary carrier 6a, and the reverse clutch 9 interrupts power transmission between the input shaft 5 and the front sun gear 6d. , The above 2 & 4 brake 10
Between the front sun gear 6d and the automatic transmission case 11 of the multi-stage transmission 3.

The planetary carrier 7a of the rear planetary gear unit 7 rotates integrally with the ring gear 6b of the front planetary gear unit 6 and is connected to the output shaft 12.

The two planetary gear units 6, 7
A low clutch drum 13a is disposed on the outer periphery of the vehicle, and the low clutch drum 13a rotates integrally with the front planetary carrier 6a and is connected to the low one-way clutch 14. Further, an intermittent low clutch 13 is interposed between the low clutch drum 13a and the ring gear 7b of the rear planetary gear unit 7.

A low one-way clutch 14 for engaging and disengaging between the planetary carrier 6a of the front planetary gear unit 6 and the automatic transmission case 11 is provided beside the rear planetary gear unit 7. And a low-and-reverse (L & R) brake 15 for preventing idling of the vehicle. Further, the torque converter 1 is provided with a lock-up clutch 16 which can directly connect the impeller and the turbine without using oil.

The multi-stage transmission 3 having such a configuration
Has four forward gears and one reverse gear, and each gear is appropriately selected by the operation of the high clutch 8, the reverse clutch 9, the low clutch 13, the 2 & 4 brake 10, and the L & R brake 15. .

Table 1 shows the operation relationship of each clutch and brake during shifting.

[0021]

[Table 1] As shown in Table 1 above, for example, when the driver shifts the select lever (not shown) from the neutral gear (N range) to the reverse gear (R range), the reverse clutch 9 and the L & R brake 15 are operated to drive the reverse gear. The stage is selected. That is, when the L & R brake 15 is engaged, the front planetary carrier 6a moves to the low clutch drum 13a.
Is fixed to the automatic transmission case 11 via the On the other hand, when the reverse clutch 9 is engaged, the engine output is transmitted from the input shaft 5 to the sun gear 6 d of the front planetary gear unit 6 via the reverse clutch 9. At this time, since the front carrier 6a is fixed to the automatic transmission case 11, the front ring gear 6b is connected to the input shaft 5 by the front pinion gear 6c.
, And the rotational force is transmitted to the output shaft 12 via the planetary carrier 7a of the rear planetary gear unit 7 to output the power of the reverse gear.

FIG. 2 shows a hydraulic circuit diagram of the automatic transmission. A high clutch 8, a low clutch 13, and a 2 & 4 brake 10, which are engaged and disengaged when a forward gear is selected, are connected in parallel to a manual valve 18 via a clutch and brake (C & B) oil passage 17, and are connected to the C & B oil passage. 17
A solenoid valve 19 for regulating the operating pressure supplied to each of the clutches 8, 13 and the 2 & 4 brake 10 is interposed.

The reverse clutch 9 which engages and disengages when the reverse gear is selected is connected to the manual valve 18 via a reverse clutch oil passage 20 which is a second hydraulic passage. Further, the L & R brake 15 to be engaged when the reverse gear or the first speed engine brake is required is provided with the L & R brake.
A solenoid valve 23 connected to a line pressure oil passage 22 via an R brake oil passage 21 and adjusting the operating pressure supplied to the L & R brake 15 to the L & R brake oil passage 21
Is interposed.

The line pressure oil passage 22 is directly connected to the manual valve 18 and communicates with a regulator pressure oil passage 24 connected to the manual valve 18. A torque converter regulator valve 25 for regulating the torque converter regulator pressure PR supplied to the release side of the lock-up clutch 16 is interposed in the regulator pressure oil passage 24.

The regulator pressure oil passage 24 has L &
A lubricating oil passage 26 for supplying lubricating oil to a lubricating portion of the automatic transmission such as the R brake 15 is branched and connected. Further, an oil cooler 27 is interposed in the middle of the lubricating oil passage 26, and an orifice 28 is provided upstream of the oil cooler 27. A lock-up clutch 16 is provided between the orifice 28 and the oil cooler 27. Is connected to a lock-up apply oil passage 29 communicating with the apply side.

On the other hand, on the release side of the lock-up clutch 16, a first
The lock-up release oil passage 30, which is a hydraulic passage, is connected.

Reference numeral 31 denotes a pressure control oil passage as a third hydraulic passage, which is an example of a control valve for variably setting a valve opening in the pressure control oil passage 31 by current control or duty ratio control. A solenoid valve 32 is interposed.
This pressure control oil passage 31 is provided between the regulator pressure oil passage 24 and the lock-up release oil passage 30 or between the line pressure oil passage 22 and the reverse clutch oil passage 20.
It is selectively connected by the switching operation of the manual valve 18.

The manual valve 18 operates in conjunction with a select lever (not shown). When the select lever is selected to a forward gear (D range, etc.), the regulator pressure oil passage 24 and the lock-up release oil passage 30 perform pressure control. The line pressure oil passage 22 communicates with the oil pressure through the oil passage 31.
And the C & B oil passage 17 and the reverse clutch oil passage 20 is released (see FIG. 3). In addition, x in a figure shows a hydraulic drain.

When the select lever is in reverse (R range)
Is selected, the connection between the hydraulic passages is switched, the regulator pressure oil passage 24 and the lock-up release oil passage 30 are directly connected, and the line pressure oil passage 22 and the reverse clutch oil passage 20 are pressurized. The communication is performed via the control oil passage 31, and the C & B oil passage 17 is released (see FIG. 4).

Next, the operation of the embodiment having the above configuration will be described. After the engine is started, the line pressure PL is sent from an oil pump (not shown) and adjusted by a pressure adjusting valve.
Is delivered to each hydraulic passage via a line pressure oil passage 22. A part of the line pressure PL is supplied to the regulator pressure oil passage 2
4, the torque converter regulator valve 2
The regulator pressure PR adjusted in 5 is supplied to the manual valve 18 and also supplied to a lubricating oil passage 26 connected in the middle thereof.

After the regulator pressure PR supplied to the lubricating oil passage 26 is reduced to a predetermined pressure by an orifice 28, a substantially constant apply pressure PAP is applied to the apply side of the lock-up clutch 16 via a lock-up apply oil passage 29. (However, PAP <PR) and, after the surplus oil pressure is cooled by the oil cooler 27, is sent as lubricating oil to the lubrication-requiring portion of the automatic transmission.

When the select lever is at the neutral position, the C & B oil passage 17 is released by the manual valve 18,
The operating pressures supplied to the high clutch 8, the low clutch 13 and the 2 & 4 brake 10, which communicate with the C & B oil passage 17, are drained, and each clutch and brake are in a non-operating state. Further, the torque converter regulator valve 2 is connected to the release side of the lock-up clutch 16.
The regulator pressure PR adjusted in step 5 is supplied, and the lock-up clutch 16 is deactivated by PAP <PR from the pressure difference between the substantially constant apply pressure PAP supplied to the apply side and the regulator pressure PR. To

Then, the driver operates the select lever to
When a forward gear, for example, a D range is selected, the line pressure oil passage 22 is directly connected to the C & B oil passage 17 via the manual valve 18 as shown in FIG.
The line pressure PL is delivered to the B oil passage 17. As a result, the hydraulic pressure controlled by each solenoid valve 19 is supplied as an operating pressure to the high clutch 8, the low clutch 13, and the 2 & 4 brake 10 communicating with the C & B oil passage 17. Further, the reverse clutch oil passage 20 communicating with the reverse clutch 9 is released, the operating pressure supplied to the reverse clutch 9 is immediately discharged, and the reverse clutch 9 is brought into a non-operating state.

Further, the regulator pressure oil passage 24 and a lock-up release oil passage 30 communicating with the release side of the lock-up clutch 16 are communicated via a pressure control oil passage 31. The pressure control oil passage 31 has a throttle opening,
A solenoid valve 32 whose opening is controlled by duty ratio control or current control based on vehicle speed, engine speed, gear position, and the like is interposed.
Thus, the release pressure PRE supplied to the release side of the lock-up clutch 16 is controlled. That is, during a transient operation until the vehicle speed, the engine speed, etc., reach a certain value, the solenoid valve 32 is fully opened, the release pressure PRE is maximized (PRE = PR), and the lock-up clutch 16 is in a non-operating state. And Then, when the vehicle speed and the engine speed reach a certain value, the solenoid valve 32 is gradually narrowed to reduce the release pressure PRE. When PAP> PRE, first, the lock-up clutch 16 enters the half-clutch state, then the lock-up clutch 16 is engaged, and the state smoothly shifts to the lock-up state.

On the other hand, when the reverse gear (R range) is selected, the regulator pressure oil passage 24 and the lock-up release oil passage 30 are directly connected as shown in FIG. Side of the lock-up clutch 1
6 remains inactive. Similarly, the C & B oil passage 17 is released, and the operating pressure supplied to the high clutch 8, the low clutch 13, and the 2 & 4 brake 10 communicating with the C & B oil passage 17 is drained, and the non-operating state is maintained.

The line pressure oil passage 22 is connected to the reverse clutch oil passage 20 via a pressure control oil passage 31, and is connected to the reverse clutch oil passage 20.
Is controlled by a solenoid valve 32 interposed in the pressure control oil passage 31 to smoothly engage the reverse clutch 9. At this time, the line pressure PL is being supplied to the L & R brake 15 while being controlled by the solenoid valve 23. Therefore, the reverse clutch 9 is maintained while the L & R brake 15 is engaged.
Can be controlled.

Therefore, it is possible to shorten the required selection time when selecting the reverse gear, and furthermore, the connection is smoothed, so that the selection shock can be reduced.

[0038]

As described above, according to the present invention,
When the forward gear is selected by the select lever, the third hydraulic passage interposed with the control valve is connected to the first hydraulic passage communicating with the lock-up clutch of the torque converter by the manual valve interlocked with the select lever. And also
When the reverse gear is selected, the third hydraulic passage is connected to the second hydraulic passage communicating with the friction engagement element for selecting the reverse gear, so that lock-up control for the lock-up clutch is performed using one control valve. And engagement control with respect to the friction engagement element for selecting the reverse gear. Therefore, the number of parts can be reduced by sharing the control valve, and the product cost can be reduced.

When the forward gear is selected, lock-up control can be always performed by the control valve, so that lock-up control can be performed at all forward gears, and the fuel consumption rate can be improved.

Further, when the reverse gear is selected, the engagement control with respect to the friction engagement element for selecting the reverse gear can be performed. For example, when the low and reverse clutch is engaged, the engagement with the friction engagement element can be performed. The control can be performed, and both the reduction of the required selection time and the reduction of the selection shock can be realized with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a power transmission train of an automatic transmission.

FIG. 2 is a hydraulic circuit diagram of a main part of the automatic transmission.

FIG. 3 is a partial detailed view of FIG. 2 when a forward gear is selected;

FIG. 4 is a partial detailed view of FIG. 2 when a reverse gear is selected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Torque converter 9 ... Friction engagement element (reverse clutch) for selection of reverse gear 16 ... Lock-up clutch 18 ... Manual valve 20 ... Second hydraulic passage (reverse clutch oil passage) 30 ... First hydraulic passage (lock) Up-release oil passage) 31 ... Third hydraulic passage (pressure control oil passage) 32 ... Control valve (solenoid valve)

Claims (1)

[Claims] 1. A first hydraulic passage communicating with a lock-up clutch of a torque converter, a second hydraulic passage communicating with a friction engagement element for selecting a reverse gear, and an operating pressure supply interposed with a control valve. When the forward gear is selected in conjunction with the third hydraulic passage of the
And a manual valve for connecting the hydraulic passage to the first hydraulic passage and switching the third hydraulic passage to the second hydraulic passage when the reverse gear is selected. Hydraulic control device.