JPH11108171A - Control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a sense of incompatibility of vibrations by removing the oil vibration of the working pressure generated by the driving period of a solenoid valve furnished in a hydraulic control circuit when the working pressure is regulated by the solenoid valve and supplied to a friction element and exhausted therefrom. SOLUTION: A control unit 300 judges the target shift stage from the signals given from a cae speed sensor 301, throttle opening sensor 302 and inhibitor switch 311 and also the shifting characteristics which were set previously, and heightens the driving frequencies of duty solenoid valves 121-123 to be driven for controlling the engaging force of a friction element at shifting only in case the time required to make shift to the target shift stage is relatively long and oil vibration is easily sensible. The control unit 300 prohibits the drive of the solenoid valves 121-123 at a high frequency when either of the battery voltage and oil temp. sensed by a voltage sensor 303 and oil temp. sensor 304 is lower than their specified values.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a control device for an automatic transmission mounted on an automobile, and more particularly to a hydraulic control circuit for engaging or releasing a predetermined friction element during a gear shift. The present invention also belongs to the technical field of a control device for an automatic transmission having a solenoid valve for supplying and discharging hydraulic oil to and from a hydraulic chamber of the friction element while regulating the hydraulic oil.

[0002]

2. Description of the Related Art Generally, an automatic transmission mounted on an automobile combines a torque converter and a transmission gear mechanism,
The power transmission path of the transmission gear mechanism is switched by a selective operation of a plurality of friction elements such as a clutch and a brake to automatically shift to a predetermined gear.
In this case, the target shift speed which is the target of the shift is usually the vehicle speed, the throttle opening of the engine, that is, the driving state of the vehicle such as the engine load, and the driving state as a parameter, the higher the vehicle speed, the lower the load. The gear is set based on a shift characteristic that is provided in advance so that a gear with a higher gear is selected. Then, the automatic shifting is achieved by controlling the engagement and disengagement operation states of the friction elements so that the target gear set in this manner is realized. In order to reduce the shift shock or the like, instead of completing the fastening operation or the releasing operation at a stroke, control for gradually engaging or releasing the friction element may be performed.

[0003] For example, during a gear change involving the exchange of a so-called friction element in which one of two friction elements is engaged and the other is released, an inertia phase is realized by preceding the engagement or release operation of one of the friction elements. The torque of the friction element is gradually reduced so that the turbine speed decreases to a predetermined speed if the turbine speed is an upshift, or increases to a predetermined speed if the turbine speed is a downshift. And change it with
And when the turbine speed approaches the predetermined speed, the friction element is completely fastened or released,
The other friction element is released or fastened. By controlling in this way,
It is possible to suppress the occurrence of interlock due to the both friction elements being in the engaged state, and to prevent the engine from being blown up due to the both friction elements being in the released state.

In this type of automatic transmission, a hydraulic control circuit for supplying and discharging operating pressure to and from a hydraulic chamber of each friction element is provided for selectively operating the plurality of friction elements. And the hydraulic control circuit
A solenoid valve for adjusting the operating pressure is provided. Then, for example, after the hydraulic pressure of the hydraulic oil discharged from the oil pump is adjusted to a predetermined line pressure by a regulator valve, the hydraulic pressure is supplied as an original pressure from the upstream side to the solenoid valve via a manual valve. When the solenoid valve is fully open, the original pressure from the upstream side is supplied as it is to the oil passage communicating with the hydraulic chamber of the friction element as the operating pressure, and the friction element is completely fastened.
When the solenoid valve is fully closed, the operating pressure is not supplied to the hydraulic chamber of the friction element, the friction element is completely released, and at an intermediate opening between them, the original pressure from the upstream side is reduced. The engagement force of the friction element is controlled by adjusting the hydraulic pressure in accordance with the opening degree, and a slip state is obtained.

In this case, the opening degree of the solenoid valve is controlled by a duty ratio. For example, at a duty ratio of 70%, the solenoid valve has a 70% ON time ratio and a 30% OFF time ratio per unit time. %, And a hydraulic pressure corresponding to the time ratio is generated by the solenoid valve.

[0006]

As described above, in the solenoid valve, the target hydraulic pressure is generated by repeating the ON-OFF operation at a predetermined ratio at a predetermined cycle of, for example, about 50 Hz. However, at this time, along with the above-described drive cycle, an oil vibration that repeats high and low in the operating pressure supplied to the hydraulic chamber of the friction element occurs, and this also appears in the operation of fastening or releasing the friction element, Finally, there is a problem that the occupant feels vibration.

The problem is that the vibration caused by the oil vibration is felt in a shift having a long shift time such as a jump shift in which the frictional element slides for a long time before and after the shift. It becomes particularly large because it becomes easier.

Accordingly, the present invention provides a method for controlling the engagement force of a friction element during a gear shift by turning on and off at a predetermined driving cycle.
The above operation is repeated, thereby addressing the above-mentioned problem in the solenoid valve configured to generate the target operating pressure, and reducing the oil vibration generated due to the above-mentioned drive cycle, and An object of the present invention is to suppress a feeling of strangeness of vibration with respect to the object.

[0009]

In order to solve the above problems, the present invention uses the following means.

First, the invention described in claim 1 of the present application (hereinafter referred to as "first invention") selectively operates by a torque converter, a speed change gear mechanism, and supply and discharge of operating pressure. A plurality of friction elements for switching the power transmission path of the gear mechanism, a hydraulic control circuit for supplying and discharging a working pressure to and from the friction elements, and a hydraulic control circuit provided in the hydraulic control circuit to adjust the working pressure A target shift speed setting means for setting a target shift speed based on an operating state of the vehicle, and controlling the solenoid valve so that a shift to the target shift speed set by the setting means is performed. A control device for controlling a solenoid valve that controls the shift in the shift only during a shift with a relatively long shift time. Characterized by comb controlled.

Next, the invention according to claim 2 (hereinafter referred to as “second
Invention ". In the first aspect, the control means controls the solenoid valve by increasing the driving frequency only when the accumulator is not provided in the oil passage between the solenoid valve and the friction element. .

According to a third aspect of the invention (hereinafter referred to as a "third invention"), an oil temperature detecting means for detecting a temperature of hydraulic oil is provided in the first or second invention, and The means controls the solenoid valve by increasing the drive frequency only when the oil temperature detected by the detection means is higher than a predetermined value.

Further, the invention according to claim 4 (hereinafter referred to as “fourth
Invention ". According to any one of the first to third aspects of the present invention, voltage detecting means for detecting a voltage of a power supply for driving the solenoid valve is provided, and the control means determines whether the voltage detected by the detecting means is a predetermined value. Only when the value is higher than the value, the driving frequency is increased to control the solenoid valve.

By using the above means, each invention of the present application operates as follows.

According to the first aspect of the invention, the solenoid valve for adjusting the operating pressure supplied to and discharged from the plurality of friction elements is controlled by the control means. The shift to the first gear is automatically performed. In this case, the solenoid valve to be controlled in the shift only when the shift is relatively long in which the oil vibration is likely to be felt is increased. Because it is controlled by the frequency, it is ON-OFF during such a shift.
The cycle of repeating the operation is shortened, whereby the degree of the oil vibration in which the operating pressure generated by the solenoid valve rises and falls is reduced, and the generation of the vibration is suppressed.

Since the solenoid valve is not driven at such a high frequency at all times, but only during a long shift time, a reduction in the durability of the valve can be suppressed.

Japanese Patent Laying-Open No. 58-137652 discloses a technique in which the driving frequency of a solenoid is changed based on the magnitude of a load during a transition period of engagement of a friction element during gear shifting. The technique aims at achieving another object different from the object of the present invention, and cannot solve the problem to be solved by the present invention.

According to the second aspect of the invention, the solenoid valve is driven at a high frequency only when the accumulator is not provided in the oil passage between the solenoid valve and the friction element. When such an accumulator is provided, and the oil vibration can be reduced by the accumulator, the solenoid valve is not driven at a high frequency, which also suppresses a decrease in durability.

According to the third invention, the solenoid valve is driven at a high frequency only when the oil temperature is higher than a predetermined value, so that the oil temperature is low and the viscosity of the hydraulic oil is high. When oil vibration is unlikely to occur, the solenoid valve is not driven at a high frequency, which also suppresses a decrease in durability.

Further, according to the fourth invention, the solenoid valve is driven at a high frequency only when the voltage of the power supply for driving the solenoid valve is higher than a predetermined value. When it is difficult to drive the solenoid valve at a high frequency, and there is a possibility that the target operating pressure itself is not generated, the solenoid valve is not driven at a high frequency, which also suppresses a decrease in durability. .

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in terms of a mechanical configuration, a hydraulic control circuit, and a control operation.

Mechanical Configuration First, the overall mechanical schematic configuration of the automatic transmission 10 according to the present embodiment will be described with reference to the skeleton diagram of FIG.

The automatic transmission 10 includes, as main components, a torque converter 20, first and second planetary gear mechanisms 30 and 40 which are arranged adjacent to each other as a transmission gear mechanism driven by the output of the converter 20. A plurality of friction elements 51 to 55 such as clutches and brakes for switching the power transmission path formed by these planetary gear mechanisms 30 and 40 and a one-way clutch 56 are provided. Third to third speeds and first and second speeds in the L range, and reverse speed in the R range are obtained.

The torque converter 20 includes a pump 2 fixed in a case 21 connected to the engine output shaft 1.
2 and the pump 22
And a stator 25 interposed between the pump 22 and the turbine 23 and supported by the transmission case 11 via a one-way clutch 24 to increase the torque. And a lock-up clutch 26 provided between the case 21 and the turbine 23 and directly connecting the engine output shaft 1 and the turbine 23 via the case 21. And
The rotation of the turbine 23 is output to the planetary gear mechanisms 30 and 40 via a turbine shaft 27.

Here, an oil pump 12 driven by the engine output shaft 1 through a case 21 of the torque converter 20 is provided on a side opposite to the engine of the torque converter 20.
Is arranged.

On the other hand, the first and second planetary gear mechanisms 30,
Reference numeral 40 denotes sun gears 31 and 41, and a plurality of pinions 32 ... 32 meshed with the sun gears 31 and 41.
42 ... 42 and these pinions 32 ... 32, 42 ... 4
2 and pinion carriers 33, 43, and ring gears 34 meshed with the pinions 32,.
44.

Then, the turbine shaft 27 and the first
A forward clutch 51 is provided between the planetary gear mechanism 30 and the sun gear 31, a reverse clutch 52 is provided between the turbine shaft 27 and the sun gear 41 of the second planetary gear mechanism 40, and a turbine shaft 27 is provided with the second planetary gear mechanism. A 3-4 clutch 53 is interposed between the pinion carrier 43 and the pinion carrier 40, and a 2-4 brake 54 for fixing the sun gear 41 of the second planetary gear mechanism 40 is provided.

Further, the ring gear 34 of the first planetary gear mechanism 30 and the pinion carrier 43 of the second planetary gear mechanism 40
The low reverse brake 55 and the one-way clutch 56 are arranged in parallel between the transmission case 11 and these components, and the pinion carrier 33 of the first planetary gear mechanism 30 and the second planetary gear mechanism Forty ring gears 44 are connected, and the output gear 13 is connected to them.

The output gear 13 is meshed with a first intermediate gear 62 on an idle shaft 61 constituting an intermediate transmission mechanism 60, and is connected to a second intermediate gear 63 on the idle shaft 61 and a differential gear. The input gear 71 of the differential gear 70 meshes with the rotation of the output gear 13 and is input to the differential case 72 of the differential 70.
The left and right axles 73, 74 are driven via the zero.

Here, the relationship between the operating state of the friction elements 51 to 55 such as the clutches and brakes and the one-way clutch 56 and the shift speed is summarized in Table 1 below.

The automatic transmission 10 shown in the above skeleton diagram
2 is specifically configured as shown in FIG. 2. As shown in FIG. 2, the transmission case 11 is provided with a turbine rotation sensor 305 used for control described later. ing.

[0032]

[Table 1] Hydraulic Control Circuit Next, the configuration of a hydraulic control circuit for supplying and discharging operating pressure to and from hydraulic chambers provided in the friction elements 51 to 55 shown in FIGS. 1 and 2 will be described with reference to FIG.

Of the above frictional elements, the 2-4 brake 54 composed of a band brake has a fastening chamber 54a and a release chamber 54b as hydraulic chambers to which the operating pressure is supplied, and operates only in the fastening chamber 54a. When pressure is supplied,
-4 When the brake 54 is engaged and operating pressure is supplied only to the release chamber 54b, when operating pressure is not supplied to both chambers 54a and 54b, and when operating pressure is supplied to both chambers 54a and 54b. When 2-4 brake 54
Is to be released. The other friction elements 51 to 53, 55 have a single hydraulic chamber, and the friction elements are fastened when the hydraulic chamber is supplied with the operating pressure.

As shown in FIG. 3, the hydraulic control circuit 10
0, the main components are: a regulator valve 101 for adjusting the discharge pressure of the oil pump 12 to generate a predetermined line pressure; a manual valve 102 for switching the range by manual operation; Reverse valve 103, bypass valve 104, and 3-4 for switching oil passages leading to friction elements 51-55
A shift valve 105, a lock-up control valve 106, first and second ON-OFF solenoid valves (hereinafter referred to as "first and second SV") 111 and 112 for operating these valves 103 to 106, and Solenoid relay valve (hereinafter referred to as “relay valve”) for switching the supply destination of the operating pressure from 1SV111
07, and first to third duty solenoid valves (hereinafter, referred to as “first to third DSVs”) that control generation, adjustment, discharge, and the like of the operating pressure supplied to the hydraulic chambers of the friction elements 51 to 55.
121, 122, 123, etc. are provided.

Here, the first and second SVs 111, 11
Each of the second and first to third DSVs 121 to 123 is a three-way valve, and can obtain a state in which the upper and downstream oil paths are communicated and a state in which the downstream oil path is drained. ing. In the latter case, the oil passage on the upstream side is shut off, so that the operating oil from the upstream side is not drained out in a drain state, and the drive loss of the oil pump 12 is reduced.

The first and second SVs 111 and 112 are O
At the time of N, the upper and downstream oil passages are communicated. Also, the first
When the third DSVs 121 to 123 are OFF, that is, when the duty ratio (the ratio of the ON time in one ON-OFF cycle) is 0%, the third DSVs 121 to 123 are fully opened to completely communicate the upper and downstream oil passages, and When the duty ratio is 10
At 0%, the oil path on the upstream side is shut off to cause the oil path on the downstream side to be in a drain state. At an intermediate duty ratio, the hydraulic pressure on the upstream side is used as the original pressure, and the duty ratio on the downstream side is reduced. An oil pressure adjusted to a corresponding value is generated.

The line pressure generated by the regulator valve 101 is supplied to the manual valve 102 via a main line 200, and is supplied to a solenoid reducing valve (hereinafter referred to as "reducing valve") 108. It is supplied to the 3-4 shift valve 105.

The line pressure supplied to the reducing valve 108 is reduced by the valve 108 to a constant pressure, and then supplied to the first and second SVs 111 and 112 via lines 201 and 202. .

This constant pressure is supplied to the relay valve 107 via the line 203 when the first SV 111 is ON, and when the spool of the relay valve 107 is located on the right side in the drawing (the same applies hereinafter). Is
Further, a pilot pressure is supplied to a control port at one end of the bypass valve 104 via the line 204 to urge the spool of the bypass valve 104 to the left. When the spool of the relay valve 107 is located on the left side, the 3-4 shift valve 105
Is supplied as pilot pressure to the control port at one end of
The spool of the 3-4 shift valve 105 is biased to the right.

When the second SV 112 is ON,
The constant pressure from the reducing valve 108 is supplied to the bypass valve 104 via a line 206, and when the spool of the bypass valve 104 is located on the right side, a lock-up control valve is further provided via a line 207. The control valve 106 is supplied as pilot pressure to a control port at one end of the control valve 106.
Bias the spool to the left. Also, bypass valve 1
When the spool No. 04 is located on the left side, the line 208
Is supplied as pilot pressure to the control port at one end of the low reverse valve 103 to urge the spool of the low reverse valve 103 to the left.

Further, the constant pressure from the reducing valve 108 is also supplied to the control port 101a of the regulator valve 101 via the line 209. In this case, the constant pressure is adjusted by the linear solenoid valve 131 provided on the line 209 according to, for example, the throttle opening of the engine. Therefore, the line pressure is adjusted by the regulator valve 101 according to the throttle opening and the like. Will be adjusted.

The main line 200 led to the 3-4 shift valve 105 is connected to the first line via the line 210 when the spool of the valve 105 is located on the right side.
The accumulator 141 communicates with the accumulator 141.
To introduce line pressure.

On the other hand, the line pressure supplied from the main line 200 to the manual valve 102 is D, S, L
Are introduced into the first output line 211 and the second output line 212 in each forward range, into the first output line 211 and the third output line 213 in the R range, and into the third output line 213 in the N range.

The first output line 211 is connected to the first output line 211.
It is led to the DSV 121 and supplies the first DSV 121 with a line pressure as a control source pressure. The downstream side of the first DSV 121 is connected to a low reverse valve 1 via a line 214.
03, and when the spool of the valve 103 is located on the right side, a further line (servo apply line)
It is guided to the engagement chamber 54a of the 2-4 brake 54 via 215. When the spool of the low reverse valve 103 is located on the left side, the spool is further guided to the hydraulic chamber of the low reverse brake 55 via a line (low reverse brake line) 216. Here, the line 21
A line 217 is branched from 4 and led to the second accumulator 142.

The second output line 212 is connected to the second output line 212.
The line pressure is supplied to the DSV 122 and the third DSV 123, the line pressure is supplied to these DSVs 122 and 123 as the control source pressure, and the line pressure is also supplied to the 3-4 shift valve 105.

The line 212 led to the 3-4 shift valve 105 is led to the lock-up control valve 106 via the line 218 when the spool of the valve 105 is located on the left side. Is located on the left side, and is further led to the hydraulic chamber of the forward clutch 51 via a line (forward clutch line) 219.

Here, the forward clutch line 2
The line 220 branched from 19 is led to the 3-4 shift valve 105. When the spool of the valve 105 is located on the left side, the line 220 communicates with the first accumulator 141 via the aforementioned line 210, and the valve 105 When the spool is located on the right side, it communicates with the release chamber 54b of the 2-4 brake 54 via the line (servo release line) 221.

The downstream side of the second DSV 122 to which the control source pressure is supplied from the second output line 212 is connected to a line 22.
The pilot pressure is supplied to the control port at one end of the relay valve 107 via the control port 2 to supply the pilot pressure to the port, thereby urging the spool of the relay valve 107 to the left. The line 22 branched from the line 222
3 is led to a low reverse valve 103, and the valve 10
When spool 3 is on the right, line 2
Leads to 24.

From this line 224, the orifice 15
1, the line 225 is branched, and the branched line 225 is led to the 3-4 shift valve 105. When the spool of the 3-4 shift valve 105 is located on the left side, the servo Release line 221
Through the release chamber 54b of the 2-4 brake 54.

The orifice 1 from the line 224
A line 226 is further branched from a line 225 branched through the line 51, and the line 226 is further branched.
Is guided to the bypass valve 104, and is guided to the hydraulic chamber of the 3-4 clutch 53 via the line (3-4 clutch line) 227 when the spool of the valve 104 is located on the right side.

Further, the line 224 is directly led to the bypass valve 104, and communicates with the line 225 via the line 226 when the spool of the valve 104 is located on the left side. That is, the line 224 and the line 225
Are connected to bypass the orifice 151.

The downstream side of the third DSV 123 to which the control source pressure is supplied from the second output line 212 is connected to the line 22.
8 and is led to the lock-up control valve 106, and when the spool of the valve 106 is located on the right side, it communicates with the forward clutch line 219.
When the spool of the lock-up control valve 106 is located on the left side, it communicates with the front chamber 26a of the lock-up clutch 26 via the line 229.

Further, a third output line 213 from the manual valve 102 is guided to the low reverse valve 103 to supply a line pressure to the valve 103. When the spool of the valve 103 is located on the left side, it is guided to the hydraulic chamber of the reverse clutch 52 via a line (reverse clutch line) 230.

The line 231 branched from the third output line 213 is led to the bypass valve 104, and when the spool of the valve 104 is located on the right side, the control of the low reverse valve 103 via the line 208 described above. The line pressure is supplied to the port as the pilot pressure, and the spool of the low reverse valve 103 is urged to the left.

In addition to the above configuration, the hydraulic control circuit 1
00 is provided with a converter relief valve 109. This valve 109 is a regulator valve 10
After the working pressure supplied from 1 through the line 232 is regulated to a constant pressure, this constant pressure is supplied to the lock-up control valve 106 via the line 233. This constant pressure is applied to the lock-up control valve 1
When the spool of the valve 106 is located on the right side, it is supplied to the front chamber 26a of the lock-up clutch 26 via the aforementioned line 229. When the spool of the valve 106 is located on the left side, the constant pressure is applied to the line 234. The air is supplied to the rear chamber 26b via the rear chamber 26b.

The lock-up clutch 26 is released when the constant pressure is supplied to the front chamber 26a, and the spool of the lock-up control valve 106 is located on the left side. When the pressure is supplied to the front chamber 26a,
The slip state is controlled according to the operating pressure.

From the manual valve 102, lines 235 leading to the main line 200 in each of the D, S, L, and N ranges are led, and the regulator valve 1
01 is connected to the pressure reducing port 101b, and the line pressure is introduced into the pressure reducing port 101b in each of the above ranges. Has become lower.

Here, the specific structure of the hydraulic actuator of the 2-4 brake 54 will be described. As shown in FIG. 4, the hydraulic actuator comprises a transmission case 11 and a cover member 54c fixed to the case 11. The piston 54e is fitted into the servo cylinder 54d composed of the above, and the above-described fastening chamber 54a and release chamber 54b are formed on both sides thereof. In addition, the piston 54e
Has a band fastening stem 54f attached thereto, the stem 54f is engaged with one end of a brake band 54g wound around a member to be braked (not shown), and the other end of the band 54g. The side is engaged with a fixing stem 54h provided in the case 11, and a piston 54e is further provided in the release chamber 54b.
A spring 54i that urges toward the 4a side, that is, the side on which the brake band 54g is loosened, is housed.

Then, operating pressure is supplied from a control valve unit constituting the hydraulic control circuit 100 to the fastening chamber 54a and the release chamber 54b via an oil hole (not shown), and a brake band is supplied in accordance with the supply state. By tightening or loosening the 54 g, the 2-4 brake 54 is engaged or released, and in particular,
In this hydraulic actuator, the piston 54
e, the pressure receiving areas on the fastening chamber 54a side and the release chamber 54b side are made substantially equal, and therefore, for example, both chambers 54a, 54
When an operating pressure equal to b is supplied, these pressures cancel each other and only the biasing force of the spring 54i acts on the release side.

On the other hand, as shown in FIG. 5, the automatic transmission 10 has the first and second
SV111, 112, first to third DSVs 121 to 123
And a control unit 300 for controlling the linear solenoid valve 131. The control unit 300 includes a vehicle speed sensor 301 for detecting the vehicle speed of the vehicle, a throttle opening sensor 302 for detecting the throttle opening of the engine, A battery voltage sensor 303 for detecting a voltage of a battery serving as a power supply of an electric system of the vehicle, an oil temperature sensor 30 for detecting an oil temperature of hydraulic oil
4. Signals from sensors such as a turbine rotation sensor 305 for detecting the rotation speed of the turbine 23 in the torque converter 20, and R, N, D,
Signals from switches such as an inhibitor switch 311 including each of the range switches 306 to 310 for detecting that the S and L shift positions (ranges) have been selected are input,
These sensors 301 to 305 and switches 306 to 3
The solenoid valves 111, 112,... According to the operating state of the vehicle or engine indicated by the signal from
The operations of 121 to 123 and 131 are controlled. FIG. 2 shows the turbine rotation sensor 305 in an attached state.

Next, the first and second SVs 111, 112
The relationship between the operating states of the first to third DSVs 121 to 123 and the supply and discharge states of the operating pressure of the friction elements 51 to 55 to and from the hydraulic chamber will be described for each shift speed.

Here, the combinations (solenoid patterns) of the operation states of the first and second SVs 111 and 112 and the first to third DSVs 121 to 123 for each gear are set as shown in Table 2 below.

In Table 2, (○) indicates the first and second SV1.
ON for 11 and 112, 1st to 3rd DSV 121
Reference numerals 123 to 123 are OFF, and all indicate a state in which the upstream oil passage is communicated with the downstream oil passage and the original pressure is supplied to the downstream as it is. (×) indicates the first and second
OFF for SV111 and 112, 1st to 3rd DS
V121 to V123 are ON.
This shows a state in which the upstream oil passage is shut off and the downstream oil passage is drained.

[0064]

[Table 2] First, in the first gear (excluding the first gear in the L range),
As shown in FIG. 6, only the third DSV 123 operates to generate an operating pressure using the line pressure from the second output line 212 as a source pressure, and this operating pressure is supplied via a line 228 to a lock-up control valve. 106. At this point, the spool of the lock-up control valve 106 is located on the right side,
The operating pressure further increases the forward clutch line 219
Is supplied to the hydraulic chamber of the forward clutch 51 as a forward clutch pressure, whereby the forward clutch 51 is engaged.

Here, the forward clutch line 2
19 is connected to the first accumulator 1 via the 3-4 shift valve 105 and the line 210.
Due to the communication with 41, the supply of the forward clutch pressure is performed gently.

Next, in the second gear state, as shown in Table 2 and FIG. 7, in addition to the above first gear state, the first DSV 12
1 also operates, and generates an operating pressure using the line pressure from the first output line 211 as a source pressure. This operating pressure is
4 to the low reverse valve 103,
At this time, since the spool of the low reverse valve 103 is located on the right side, it is further introduced into the servo apply line 215, and the engagement chamber 54 of the 2-4 brake 54
a is supplied as servo apply pressure. This allows
In addition to the forward clutch 51, a 2-4 brake 54 is engaged.

Since the line 214 communicates with the second accumulator 142 via the line 217, the supply of the servo apply pressure or the application of the 2-4 brake 54 is performed gently. When the spool of the low reverse valve 103 moves to the left when shifting to the first speed in the L range, which will be described later, the hydraulic oil stored in the accumulator 142 is transmitted from the low reverse brake line 216 to the hydraulic pressure of the low reverse brake 55. The room is precharged.

In the state of the third speed, as shown in Table 2 and FIG. 8, in addition to the state of the second speed, the second DS
V122 also operates, and generates an operating pressure using the line pressure from the second output line 212 as a source pressure. This operating pressure is supplied to the low reverse valve 103 via the line 222 and the line 223. At this time, since the spool of the valve 103 is located on the right side, the line 2
24.

This operating pressure is introduced from the line 224 to the line 225 via the orifice 151,
At this point, since the spool of the 3-4 shift valve 105 is located on the left side, the servo is further moved to the release chamber 54b of the 2-4 brake 54 via the servo release line 221. Supplied as release pressure. Thereby, 2-4 brake 5
4 is released.

Also, the orifice 1
From line 225 branched through 51, line 22
6 is branched, and the operating pressure is guided to the bypass valve 104 by the line 226. At this time, the spool of the bypass valve 104 is located on the right side, and further, via the 3-4 clutch line 227. The pressure is supplied to the hydraulic chamber of the 3-4 clutch 53 as a 3-4 clutch pressure. Therefore, in the third speed, the forward clutch 51 and the 3-4 clutch 53 are engaged, while the 2-4 brake 54 is released.

In the third speed state, the second DSV 122 generates the operating pressure as described above,
The spool of the relay valve 107 is moved to the left by being supplied to the control port 107a of the relay valve 107 via 2.

Further, in the fourth speed state, as shown in Table 2 and FIG. 9, the third DSV 123 stops generating the operating pressure and the first SV 111 operates in the third speed state.

By the operation of the first SV 111, a constant pressure from the line 201 is supplied to the relay valve 107 via the line 203. As described above, the spool of the relay valve 107 moves to the left at the third speed. , The constant pressure is
This is supplied to the control port 105a of the four-shift valve 105, and the spool of the valve 105 moves to the right. Therefore, the servo release line 221 is divided into the line 22 branched from the forward clutch line 219.
0, and the release chamber 54b of the 2-4 brake 54 communicates with the hydraulic chamber of the forward clutch 51.

Then, as described above, the third DSV 123 stops generating the operating pressure and the downstream side is set in the drain state, so that the servo release pressure in the release chamber 54b of the 2-4 brake 54 and the forward clutch 51 Of the third DSV via the lock-up control valve 106 and the line 228.
It will be drained at 123.
The brake 54 is engaged again, and the forward clutch 51 is released.

On the other hand, at the first speed in the L range, Table 2 and FIG.
As shown in FIG. 0, the first and second SVs 111 and 112 and the first and third DSVs 121 and 123 operate and the third DSVs 121 and 123 operate.
The operating pressure generated by V123 is 1 such as D range.
Similarly to the speed, the hydraulic pressure is supplied to the hydraulic chamber of the forward clutch 51 via the line 228, the lock-up control valve 106, and the forward clutch line 219 as the forward clutch pressure, and the forward clutch 51 is engaged. At this time, the operating pressure is introduced into the first accumulator 141 through the line 220, the 3-4 shift valve 105 and the line 210, so that the forward clutch 51 is loosely engaged. The points are the same as those of the first speed such as the D range.

Further, by the operation of the first SV 111, pilot pressure is supplied to the control port 104a of the bypass valve 104 via the line 203, the relay valve 107, and the line 204, and the spool of the valve 104 is moved to the left. Accordingly, the operating pressure from the second SV 112 is reduced by the line 206 and the bypass valve 104.
And is supplied to the control port 103a of the low reverse valve 103 to move the spool of the low reverse valve 103 to the left.

Accordingly, the operating pressure generated by the first DSV 121 is supplied as a low reverse brake pressure to the hydraulic chamber of the low reverse brake 55 via the line 214, the low reverse valve 103, and the low reverse brake line 216. The low reverse brake 55 is engaged in addition to the clutch 51, and the first speed at which the engine brake operates is obtained.

Further, in the R range, as shown in Table 2 and FIG. 11, the first and second SVs 111 and 112 and the first to
The third DSVs 121 to 123 operate. However, the second,
Regarding the third DSVs 122 and 123, the supply of the original pressure from the second output line 212 is stopped, so that no operating pressure is generated.

In this R range, the first,
Since the second SVs 111 and 112 are operated, the spool of the bypass valve 104 moves to the left and the spool of the low reverse valve 103 also moves to the left as in the case of the first speed in the L range. Then, in this state, the operating pressure is generated by the first DSV 121,
This is supplied to the hydraulic chamber of the low reverse brake 55 as a low reverse brake pressure.

On the other hand, in the R range, the manual valve 1
02, a line pressure is introduced into the third output line 213,
This line pressure is supplied as the reverse clutch pressure to the hydraulic chamber of the reverse clutch 52 via the low reverse valve 103 and the reverse clutch line 230 whose spool has moved to the left as described above. Therefore, the reverse clutch 52 and the low reverse brake 55 are engaged.

The third output line 213 has N
Since the line pressure is also introduced from the manual valve 102 in the range, when the spool of the low reverse valve 103 is located on the left side, the reverse clutch 52 is set in the N range.
Is concluded.

Control Operation Next, among the control operations by the control unit 300, a characteristic control operation for automatic shifting will be described.

This automatic shift control is performed according to the main program shown in the flowchart of FIG.
Various sensors 301 to 305 and switches 306 to
After reading an input signal from the engine 310 or the like and performing a failure determination, specifically, a failure determination between the turbine rotation sensor 305 and the inhibitor switch 311, a shift in which the vehicle speed and the throttle opening are previously set as parameters is performed. A shift position is determined based on a schedule map (shift characteristics), and then duty driving is performed on the first to third DSVs 121 to 123 to be operated in a target shift control for the determined shift position. The frequency is determined, and then the first to third DSVs 12 are determined.
Calculate the duty ratio for 1-123
These are output to the SVs 121 to 123.

Hereinafter, each step in the flowchart will be described one by one, and thereafter, the effects and the like obtained by this automatic shift control will be described.

First, input signal reading and failure determination shown in FIG. 12 are performed according to the program shown in the flowchart of FIG. 13, and in steps S11 to S20, the sensors 301 to 305 and switches 306 to 306 shown in FIG.
After reading the signals from the respective 310, the failure determination of the turbine rotation sensor 305 and then the failure determination of the inhibitor switch 311 are performed.

In this case, the failure determination of the turbine rotation sensor 305 is performed in accordance with the program shown in the flowchart of FIG. 14. At step S21, it is determined that the N range has not been selected, and at step S22, the vehicle speed V becomes the predetermined vehicle speed. V1, for example, when it is determined to be 40 km / h or more, the routine proceeds to step S23, where the turbine speed N
It is determined whether or not t is 0 rpm. If it is determined that t is not 0, the turbine rotation sensor 3 is determined in step S24.
05 is normal, while it is determined to be 0, the turbine rotation sensor 3 is determined in step S25.
05 is determined to be a failure, specifically, a failure in which a signal relating to the turbine speed is not output.

Here, the reason why the failure determination of the turbine rotation sensor 305 is not performed when the N range is selected or when the vehicle speed V is lower than the predetermined vehicle speed V1 is that the determination itself cannot be performed or the determination accuracy decreases. Because

Instead of the above-described failure determination, the theoretical turbine speed is calculated from the vehicle speed and the gear ratio of the transmission gear mechanism, etc., and the theoretical turbine speed and the turbine speed sensor 305 actually detect the turbine speed. The turbine rotation sensor 305 may be determined to be faulty when the deviation from the turbine rotation speed is larger than a predetermined value. In such a case, similarly to the above, the failure determination is not performed when the N range is selected or when the vehicle speed is relatively low, and the determination accuracy is also determined during the shift control in which the turbine speed significantly changes. Failure determination is not performed for the above reasons.

Next, the failure determination of the inhibitor switch 311 is performed according to the program shown in the flowchart of FIG. 15, and R and R are determined in steps S26 to S35, respectively.
N, D, S, L range switches 306 to 310 are set to O
If N, it is determined that the corresponding range has been selected, while if it is determined that none of the range switches 306 to 310 is ON, such a state (time measurement by the failure determination timer T) is performed in steps S36 to S38. Is continued for a predetermined time T1 or more, it is determined in step S39 that the inhibitor switch 311 is out of order.

Here, any of the range switches 306 to
The reason why the failure determination of the inhibitor switch 311 is not performed until the state in which the 310 is not ON for more than the predetermined time T1 is that none of the range switches 306 to 310 is ON for a very short time during the range switching operation by the driver. It is because it becomes a state.

When it is determined that the inhibitor switch 311 has failed, the vehicle speed V is determined in step S40.
Is determined to be not less than the predetermined vehicle speed V2, for example, 100 km / h. If it is determined that the vehicle speed is not less than the predetermined vehicle speed V2, the routine returns as it is, whereas if it is determined that the vehicle speed is not more than the predetermined vehicle speed V2 Includes step S41
It is determined that the range is the R range. This R
The process of determining the range is performed so that the combination (solenoid pattern) of the operating states of the first to third DSVs 121 to 123 is the same as the solenoid pattern at the third speed in the D range in the determination of the next shift position. belongs to.

Even when it is determined that the inhibitor switch 311 is faulty, if the vehicle speed V is equal to or higher than the predetermined vehicle speed V2, the process returns without going through step S41. In this case, the inhibitor switch 311 is turned off. Immediately before it is determined that a failure has occurred, step S2
The range determined in any of 7, S29, S31, S33, and S35 is held. However, since the predetermined vehicle speed V2 is set to a relatively high value of about 100 km / h, the D range is maintained in many cases. When the vehicle speed V falls below the predetermined vehicle speed V2, the R range is determined.

Next, the gear position determination shown in FIG.
6 is performed according to the program shown in the flowchart. First, when it is determined in steps S42 and S43 that the range is the R range or the N range, the process proceeds to step S44, and the third speed is selected. This is because, as shown in Table 2 above, in the R range, the first to third DSVs 121 to 123 are all turned off, and this solenoid pattern is the same as the solenoid pattern in the third range of the D range. Yes, and N
This is because the solenoid patterns of the first to third DSVs 121 to 123 in the range are all OFF as in the case of the third speed in the D range.

Therefore, not only when the R range is actually selected by the driver, but also when the inhibitor switch 311 is determined to be faulty, the inhibitor switch 3
11 is determined to be malfunctioning, and the vehicle speed V is equal to the predetermined vehicle speed V
Even if the R range is determined as a result of the determination that it is less than 2, the same solenoid pattern as in the D range third speed is selected.

On the other hand, when the range is not the R range or the N range but the forward travel range of any of D, S, and L, the routine proceeds to step S45, where the turbine rotation sensor 30
It is determined whether or not 5 is faulty. If it is not faulty, the range is determined in step S46, and one of the first to fourth speeds is determined according to the vehicle speed and the throttle opening. Setting of a normal target shift speed for selecting the shift speed is performed.

Here, in the memory of the control unit 300, for example, as shown in FIGS.
The shift schedule is set in advance so that the higher the vehicle speed and the lower the load, the higher the speed is selected by using the vehicle speed V and the throttle opening θ as parameters for each of the forward travel ranges of the range, the S range, and the L range. The control unit 300 stores a map (shift characteristics).
Determines the gear position by applying the measured values of the vehicle speed and the throttle opening to the determined range map. In this case, the S range can be selected at a higher speed and the load can be smaller than the D range, and the L range can be selected at a lower speed than the S range. In the shift schedule map, the shift line in the upshift direction and the shift line in the downshift direction do not coincide with each other, and hysteresis for preventing hunting is provided, but is omitted in FIGS. 17 to 19. is there.

On the other hand, if the turbine rotation sensor 305 has failed in step S45, the process proceeds to step S47, in which the range is similarly determined, and the target gear position is set according to the vehicle speed and the throttle opening. At this time, the selection of the fourth speed is prohibited, and the target gear is set from among the first to third speeds.

The range in which the fourth speed is prohibited is the D range. In this case, for example, the D range shown in FIG.
In the range map, the third and fourth speed regions are all changed to the third speed region, and in addition, the speed change line between the second and third speeds is shifted to a higher vehicle speed and a lower load side, or By using the map for the S range shown in FIG. 18 instead of the map for the D range, the fourth speed prohibition is realized.

If the turbine rotation sensor 305 is out of order and the selection of the fourth speed is prohibited, step S
The program proceeds to 48, where it is determined whether the shift is not a 3-2 downshift, that is, if the current shift speed is the third speed, whether or not the second speed has been set as the target shift speed from the map. If the -2 downshift is to be performed, the process proceeds to step S49, and the 3-2 downshift is prohibited. If the 3-2 downshift is not performed, the third speed is set in step S44. In the same manner as when the target gear is selected in step S46 and when the target gear is normally selected in step S46, gear shift control is executed in step S50 so that the selected gear is realized.

Thus, if the range is the R range or the N range, a 3-speed solenoid pattern is realized.
If the target speed is normally set without the failure of the turbine rotation sensor 305 in the forward travel range of S and L, the shift control to the normally set target speed is executed, and D and S are executed. , L, when the turbine rotation sensor 305 is out of order and the target shift speed is set under the fourth-speed prohibition condition, 1-2 shift, 1-3 shift,
2-3 shift upshifts or 3-1 shifts, 2
One of the downshifts of the -1 shift is executed. Therefore, if the 3-2 downshift is prohibited in step S49, then step S49 is executed.
When the first speed is selected from the shift schedule map in 47, a 3-1 shift is performed in step S50 to escape from the third speed.

Next, the duty drive frequency determination shown in FIG. 12 is performed according to the program shown in the flowchart of FIG. 20, and when it is determined in step S51 that the oil temperature is equal to or lower than the predetermined value, the battery voltage is reduced in step S52. When it is determined that the speed is not more than the predetermined value, when it is determined in step S53 that the shift is not a 4-2 jump downshift, or when the throttle opening is not fully closed in step S54, that is, when the driving force of the engine is automatically When it is determined that it is the time of the forward drive (at the time of power-on) transmitted to the axles 73 and 74 or the drive wheels via the transmission 10 or the like, the process proceeds to step S55 and proceeds to step S55. As the drive frequency of the first to third DSVs 121 to 123 to be operated in the shift control to the target shift speed determined in the shift position determination, Frequency, while selecting for example 50 Hz, the oil temperature and the battery voltage is not less than a predetermined value,
The shift is a 4-2 jump downshift, and the throttle opening is fully closed, that is, the drive wheel or the axle 73,
When the inertia driving force of 74 is the reverse drive (at the time of power-off) transmitted to the engine side, the process proceeds to step S56, where the duty solenoid valve to be operated in the above-described 4-2 jump downshift shift control, Specifically, the third DSV 12 to be operated so that the forward clutch 51 in the released state at the fourth speed is brought into the engaged state at the second speed
A high frequency, for example, 83 Hz is selected as the driving frequency of No. 3.

Therefore, even in the 4-2 jump downshift, the third DSV 123 is driven at the normal frequency when the power is turned on or when the oil temperature or the battery voltage is equal to or lower than a predetermined value.

Next, the operational effects and the like obtained by the above automatic shift control will be described.

As described above, shifting is achieved by selectively switching the engaged state of the plurality of friction elements 51 to 55 such as clutches and brakes and the operating state of the one-way clutch 56. The target target gear is D, S, L as shown in FIGS.
Is determined based on a shift schedule map set in advance for each range according to the driving state. As a result, for example, upshifting such as 1-2 shifting, 3
A downshift such as -2 shift is executed.

At this time, if the target shift speed is achieved by engaging or disengaging only one friction element, the shift can be realized only by performing the engagement or release operation of the friction element. Depending on the type, it may be necessary to perform so-called replacement of the friction element, in which one friction element is engaged or released and another friction element is released or fastened in reverse. When shifting such a change of the friction elements, if the timing of the operations of the two friction elements is not taken, both the friction elements will be in the engaged state and an interlock will occur. The engine will blow up.

Therefore, in general, in an upshift, in which the turbine speed decreases before and after the speed change, an inertia phase is realized in advance of the engagement operation of the engagement-side friction element, whereby the turbine speed is reduced to a predetermined rotation speed. At this time, the release-side friction element is released and the engagement-side friction element is completely fastened at the timing when the number decreases.

On the other hand, in a downshift where the turbine speed increases before and after the shift, when the power is on with the accelerator pedal depressed, the release operation of the release-side friction element is preceded and the inertia phase is set. Realized,
As a result, the engagement-side friction element is fastened and the release-side friction element is completely released at the timing when the turbine speed has increased to a predetermined speed. On the other hand, when the power is off when the accelerator pedal is not depressed, the turbine rotation must be increased by the inertia torque on the drive wheel side. As in the case of the upshift, the inertia phase is realized by prioritizing the engagement operation of the engagement-side friction element, whereby the release-side friction element can be released at a timing when the turbine speed has increased to a predetermined speed. Is being done.

Therefore, in a shift involving switching of the friction element, it is necessary to detect the turbine rotational speed in order to achieve the switching timing. At that time, the turbine rotational sensor 305 for detecting the turbine rotational speed fails. Then, when the turbine speed cannot be detected, the timing of starting the operation of the friction element to be fastened or released later cannot be determined, and as a result, the interlock, the engine blow-up, or the shift Shock suppression is no longer effective and poses a problem.

Here, the relationship between the friction element to be engaged and the friction element to be released for each type of shift in the automatic transmission 10 is summarized in Table 3 below. In the table, FWD indicates the forward clutch 51, and 3-4C indicates the forward clutch 51.
-4 clutch 53, 2-4B is 2-4 brake 54
OWC indicates the one-way clutch 56, respectively.

[0110]

[Table 3] As described above, at the first speed, the forward clutch 51 is engaged, and the one-way clutch 56 is operated, that is, rotation is stopped, and the ring gear 3 of the first planetary gear mechanism 30 is rotated.
4 and the pinion carrier 43 of the second planetary gear mechanism 40 are in a state of being fixed to the transmission case 11. On the other hand, at the second speed, the forward clutch 51 is also engaged, and the 2-4 brake 54 is also Since the one-way clutch 56 is engaged and the one-way clutch 56 is freely rotated, in this upshift from the first speed to the second speed, 2-4
With the brake 54 engaged, the one-way clutch 5
6 needs to be changed from the locked state to the free state. However, in this case, by gradually applying the 2-4 brake 54 by operating pressure control by the first DSV 121, the ring gear 34 of the first planetary gear mechanism 30 and the pinion carrier 43 of the second planetary gear mechanism 40 are one-way. Since the clutch 56 starts rotating in the free direction and the locked state is released naturally, as shown in Table 3 above, regardless of the turbine speed detected by the turbine speed sensor 503, the 2-4 brake 54 and the one-way Clutch 56
The timing of the replacement is set. Therefore, even when the turbine rotation sensor 503 fails, this 1-
The two shifts can be executed without prohibition.

Similarly, in the 1-3 shift operation involving the changeover between the 3-4 clutch 53 and the one-way clutch 56, the turbine pressure can be gradually increased only by gradually engaging the 3-4 clutch 53 by operating pressure control by the second DSV 122. 3-4 clutch 53 and one-way clutch 5 regardless of number
6, it is not necessary to prohibit the timing of the replacement. In this case, the 3-4 shift valve 10
5, the servo release line 221 and the 3-4 clutch line 227 are in communication with each other. The 3-4 clutch pressure is generated by the second DSV 122 and the servo release pressure is generated at the same time. Even if pressure is generated, the 2-4 brake 54 is not engaged.

On the other hand, in the 1-4 shift, the 2-4 brake 54 is controlled by the operating pressure control by the first DSV 121 and the second DSV 1
The 3-4 clutch 53 enters the engagement operation first by the operating pressure control by 22, whereby the third DSV 123 is turned off at the timing when the turbine speed decreases to a predetermined value.
Since the forward clutch pressure is released, when the turbine rotation sensor 503 fails, the timing for releasing the forward clutch pressure cannot be achieved, and therefore, it is preferable that the 1-4 downshift is prohibited. In this case, the first SV 111 is turned on during the shift, and as a result,
Servo release line 2 via 4-shift valve 105
Since the state in which the 21 and the 3-4 clutch line 227 are in communication is switched to the state in which the servo release line 221 and the forward clutch line 219 are in communication,
The servo release pressure supplied to the 2-4 brake 54 until the first SV 111 is turned on is drained together with the forward clutch pressure, and from this point on, the 2-4 brake 54 starts engaging operation.

Conversely, considering the downshift from the fourth speed, especially when the power is turned on, the release operation of the release-side friction element is preceded as described above. 54, the 3-4 clutch 53 in the 4-2 shift, and the 2-4 brake 54 and the 3-4 clutch 53 in the 4-1 shift, respectively, perform the disengagement operation first, thereby increasing the turbine speed to a predetermined value. At this timing, the third DSV 123 is turned ON to supply the forward clutch pressure, so that when the turbine rotation sensor 503 fails, the timing for supplying the forward clutch pressure cannot be achieved, and therefore, downshifting from the fourth speed may be prohibited. preferable. From this point of view, the 1-4 upshift to the fourth speed or the 2-4 described later.
Upshifts and 3-4 upshifts are preferably prohibited when the turbine rotation sensor 503 fails.

Next, the 2-3 shift of the same upshift is performed by the engagement operation of the 3-4 clutch 53 and the 2-4 brake 5.
In this case, since the servo release line 221 and the 3-4 clutch line 227 communicate with each other via the 3-4 shift valve 105, the operation pressure is controlled by the second DSV 122. 3
Since the servo release pressure is generated simultaneously with the generation of the −4 clutch pressure, the engagement operation of the 3-4 clutch 53 and the
The timing of the release operation of the -4 brake 54 is achieved. Therefore, even when the turbine rotation sensor 503 fails, the 2-3 shift can be executed without prohibition.

On the other hand, in the 2-4 shift, the 3-4 clutch 53
Since the timing for releasing the forward clutch 51 after the engagement operation is advanced cannot be achieved without depending on the turbine speed, and the timing for the downshift from the fourth speed cannot be obtained as described above, It is preferable that the 2-4 shift be prohibited when the turbine rotation sensor 503 fails.

Next, the 3-4 shift of the same upshifting involves switching between the operation of engaging the 2-4 brake 54 and the operation of disengaging the forward clutch 51.
When the V111 is turned on, the servo release lines 221 and 3-4 are connected via the 3-4 shift valve 105.
The state in which the clutch line 227 is in communication with the servo release line 221 and the forward clutch line 2
19, the servo release pressure and the forward clutch pressure can both be drained by turning off the third DSV 123 at this time. Therefore, the engagement operation of the 2-4 brake 54 and the forward operation can be performed. Timing with the disengagement operation of the clutch 51 is achieved. Therefore, the turbine rotation sensor 50
It is not necessary to basically prohibit the 3-4 shift even in the case of the failure of the third gear, but as described above, it is not possible to take the timing in the downshift from the fourth gear when the turbine rotation sensor 503 fails. Consequently, it is preferable that the 2-4 shift be prohibited when the turbine rotation sensor 503 fails.

Next, regarding the downshift, 2-1.
In the shift and the 3-1 shift, the 2-4 brake 54 or the 3-4 clutch 53 is gradually released in reverse to the above-mentioned 1-2 shift and 1-3 shift, so that the first planetary gear mechanism is formed. 30 ring gear 34 and second planetary gear mechanism 40
Of the pinion carrier 43 gradually decreases, and the one-way clutch 56 naturally locks. Therefore, regardless of the turbine rotation speed detected by the turbine rotation sensor 503, the timing of switching between the 2-4 brake 54 or the 3-4 clutch 53 and the one-way clutch 56 is achieved, and even when the turbine rotation sensor 503 fails, The 2-1 downshift and 3-1 downshift can be executed without prohibition.

On the other hand, in the same downshift,
In the -2 shift, the disengagement of the 3-4 clutch 53 and the engagement of the 2-4 brake 54 cannot be timed. Therefore, when the turbine rotation sensor 503 fails, the 3-2 downshift is prohibited. Is preferred.

That is, in this case, the servo release lines 221 and 3-
Since the four clutch lines 227 are in communication with each other, the duty ratio of the second DSV 122 is simply changed from 0% to 1%.
Only by gradually shifting the pressure to 00%, the 3-4 clutch pressure and the servo release pressure are simultaneously released and the 3-4 clutch 53
Is released and the 2-4 brake 54 is engaged.
However, in reality, the switching of the frictional elements does not intersect well because the operating pressure is released in the same manner, but the 3-4 clutch 53 2-4 before is released
The brake 54 is tightened, and conversely, the 2-4 brake 54
Therefore, the problems of interlock, engine blow-up, and shift shocks cannot be avoided. Therefore, it is necessary to determine an appropriate changeover timing based on the turbine speed, regardless of whether the disengagement or the fastening operation is performed at the time of power-on or power-off. Therefore, the turbine rotation sensor 5
In the event of a failure in 03, it is preferable to inhibit the 3-2 downshift.

Based on the above results, in this automatic shift control, steps S21 to S25 in the above program are executed.
Then, it is determined whether or not the turbine rotation sensor 305 is normal or has failed, and in accordance with the determination result, the gear position determination, in particular, the characteristic gear position determination in steps S45 to S50 is performed.

That is, when the turbine rotation sensor 305 is normal, it is possible to determine an appropriate changeover timing based on the turbine rotation speed. Therefore, the process proceeds from step S45 to steps S46 and S50, and from the first speed to the fourth speed. The selection of a normal speed stage without restriction and the speed change control targeting that speed stage are executed.

On the other hand, if the turbine rotation sensor 305 is out of order, it is not possible to determine the appropriate replacement timing based on the turbine rotation speed.
From 45, the process proceeds to step S47 to select a gear at the time of failure in which selection of the fourth speed is prohibited. Accordingly, the 1-4 shift and the 2-4 shift in which the timing of changing the friction element cannot be determined regardless of the turbine speed are prohibited, and the timing of changing the friction element regardless of the turbine speed cannot be determined. The shift down from the first speed is prohibited, and the timing of changing the friction element can be determined regardless of the turbine speed, but the shift to the fourth speed is preferably prohibited. The 3-4 shift is prohibited. become. In addition, in addition to step S48,
Since the 3-2 downshift is prohibited in S49, it is determined from these that if the turbine rotation sensor 305 is out of order, it is not possible to take the timing of changing the friction element regardless of the turbine speed. Shifts are respectively prohibited, and as a result, problems such as shift shocks are avoided.

Next, another operation and effect obtained by the above automatic shift control will be described.

As described above, the control unit 30
0 stores a shift schedule map set in advance for each forward travel range of the D range, the S range, and the L range. The shift schedule map according to the range selected by the driver and the actual driving schedule are stored. From the state, the target gear is set, and as a result, the 1st to 4th gears in the D range,
The first to third speeds in the range and the first to second speeds in the L range are obtained.

At this time, if the inhibitor switch 311 fails and it is not possible to determine which traveling range is selected, the map cannot be selected, so that the target gear position cannot be set or the current operating state cannot be set. There are problems such as setting of gears that do not match the above.

Therefore, conventionally, at the time of such a failure, as a fail-safe measure, it is customary to select a 3-speed solenoid pattern in which all the first to third DSVs 121 to 123 are turned off as shown in Table 2 above. It has been. This is, of course, in addition to being able to continue the forward running at the third speed, there is also a necessary driving torque at the time of starting after stopping, and as shown in Table 2 above,
First to third DSVs 121 to 123 in D range 3rd speed
Is the same as the solenoid pattern in the R range, and the reverse speed in the R range after the stop is obtained.

However, if the solenoid pattern is always changed to the third-speed solenoid pattern at the time of such a failure, the following problem occurs.

That is, the failure of the inhibitor switch 311 is detected during traveling at a relatively low and medium vehicle speed, for example, at the third speed in the D range or the second speed in the S range, and as a result,
If the third speed is achieved by switching to the solenoid pattern in which all of the first to third DSVs 121 to 123 are turned off, there is little problem. For example, the vehicle is traveling at a relatively high vehicle speed at the fourth speed in the D range. Inhibitor switch 31
1 is detected, and as a result, the first to third DSVs 12 are detected.
When all the first to 123 are turned off and the third speed is achieved,
The engine is over-rotated.

Therefore, in this automatic transmission control, in order to cope with such a problem, in steps S26 to S39 in the above program, it is determined whether the inhibitor switch 311 is normal or faulty. In step S40, the vehicle speed is 100 km, which is a relatively high vehicle speed.
/ H or more, the routine returns without performing the R range determination in step S41, and returns to step S40.
Only when the vehicle speed is less than the relatively high vehicle speed of 100 km / h, the R range is determined in step S41.

As a result, at the time of high vehicle speed, the range immediately before the inhibitor switch 311 is determined to be faulty (in most cases, the D range) is maintained as it is, and the subsequent gear position determination is performed based on the shift schedule map of the range. The gear stage is normally selected, so that
For example, if the vehicle is running at the fourth speed, the fourth speed is maintained as it is, so that the engine overspeed is avoided.

On the other hand, at low vehicle speed, the R range is determined.
The process proceeds from step 2 to step S44 to select the third speed. As a result, in step S50, the shift speed is switched to the third speed, so that the forward traveling can be continued at the third speed, and starting or retreating after stopping is also possible. Becomes

That is, when the vehicle speed is high, the inhibitor switch 3
When the 11th failure is determined, the 4th speed is maintained as it is, and then the 3rd speed is switched to the 3rd speed which can be used for both forward and reverse when the vehicle speed is reduced to such a level that the engine does not overspeed.

Next, a description will be given of still another operation and effect obtained by the above-mentioned automatic shift control, particularly an operation and effect obtained by the duty drive frequency judgment.

As described above, in upshifting,
While the inertia phase is realized by the fastening operation of the fastening side friction element, thereby reducing the turbine speed,
In the power-down downshift, an inertia phase is realized by the release operation of the release-side friction element, thereby increasing the turbine speed.On the power-off downshift, the same as in the upshift,
The inertia phase is realized by the fastening operation of the fastening-side friction element, thereby increasing the turbine speed.

Therefore, during the period of the inertia phase, the frictional element on the engagement side or the release side for decreasing or increasing the turbine speed is slipped by feedback control or the like. Therefore, any one of the first to third DSVs 121 to 123 that generate the respective operating pressures on the engagement-side or release-side friction elements is driven at a predetermined duty ratio. At this time, if a duty ratio of, for example, 70% is set, the duty solenoid valve is set to 1 ON-
A voltage is applied such that the ratio of the ON time is 70% and the ratio of the OFF time is 30% in the OFF cycle.
The ON-OFF cycle is set to, for example, about 50 Hz. As a result, an oil vibration that alternates in height with the above-described drive cycle occurs in the working pressure supplied to the hydraulic chamber of the friction element,
This also appears in the operation of fastening or releasing the friction element, causing a problem that the occupant eventually feels vibration.

Here, for each type of shift in the automatic transmission 10, the relationship between a friction element that is slipping in the inertia phase and a duty solenoid valve that generates an operating pressure for the friction element. Are summarized in Tables 4 and 5 below. In the table,
FWD is forward clutch 51, 3-4C is 3-4
The clutch 53, the 2-4B the 2-4 brake 54, the L
/ R indicates the low reverse brake 55, respectively.
The downshift to the first speed when the power is turned off in FIG. 7 shows the case of a manual downshift to the first speed in the L range.

[0137]

[Table 4]

[0138]

[Table 5] For example, in a 1-2 upshift, the first DSV
The servo apply pressure is gradually increased by the duty control of 121, whereby the 2-4 brake 54 is engaged while sliding. At this time, the engagement operation of the 2-4 brake 54 is affected by the oil vibration of the servo apply pressure generated by the first DSV 121,
Vibration will occur. However, in the hydraulic control circuit 100 of the automatic transmission 10, FIG.
As shown in FIGS. 6 to 11, since the second accumulator 142 is provided via the branch line 217 to the line 214 communicating with the servo apply line 215 via the low reverse valve 103, the 2-4 brake 54
The oil vibration at the servo apply pressure supplied to the fastening chamber 54a is reduced by the second accumulator 142, so that the trouble of the vibration is suppressed.

The effect of reducing the oil vibration by the second accumulator 142 is not limited to the 1-2 shift, and the duty control of the first DSV 121 is performed in order to engage or release the 2-4 brake 54 while sliding in the inertia phase. The same can be obtained in other shifts.

The effect of the second accumulator 142 to reduce the oil vibration is that the spool of the low reverse valve 103 is located on the left side, the line 214 communicates with the low reverse brake line 216, and the low reverse brake line 216 is connected in the inertia phase. The same can be obtained in a manual downshift to the first speed in the L range in which the duty control of the first DSV 121 is performed in order to engage the brake 55 while sliding.

On the other hand, in a 1-3 upshift, for example, the 3-4 clutch pressure is gradually increased by the duty control of the second DSV 122, whereby the 3-4 clutch 53 is engaged while sliding. Done. In that case, 3 through the 3-4 shift valve 105
-4 clutch line 227 and servo release line 22
1 is in communication with the second DSV 122,
And the servo release pressure is also generated at the same time when the clutch pressure is generated.
Supplied to Also, the servo apply pressure is generated by the first DSV 121, and this is applied to the servo apply line 2
15 to the engagement chamber 54 a of the 2-4 brake 54. Accordingly, the 2-4 brake 54 is not engaged, and at this time, the servo release lines 221 through 221 through the servo of the 2-4 brake 54 in which the working oil is guided to both the chambers 54a and 54b. 3-4
The clutch line 227 is linked to the servo apply line 215, so that the 3-4 clutch pressure or servo release pressure and the servo apply pressure transfer direct effects to each other.

Therefore, the oil vibration of the 3-4 clutch pressure generated by the second DSV 121 is reduced by the 2-4 brake 54.
Is reduced by the second accumulator 142 via the servo, and as a result, the trouble of vibration is suppressed.

The effect of reducing the oil vibration by the second accumulator 142 via the servo of the 2-4 brake 54 is not limited to the 1-3 shift, and the 3-4 clutch 53 is slid in the inertia phase. The same can be obtained in other shifts in which the second DSV 121 is duty-controlled for engagement or release.

On the other hand, the forward clutch pressure is gradually increased by the duty control of the third DSV 123, whereby the forward clutch 51 is engaged while sliding, so that the 4-2 shift or the 4-3 shift at power-off is performed. In the above, the effect of the direct or indirect oil vibration reduction by the second accumulator 142 as described above cannot be obtained.

That is, in any case, first, the first SV 111 is turned off at the beginning of the shift, and as a result, the forward clutch line 219 which has been in communication with the servo release line 221 through the 3-4 shift valve 105 until then is turned off. The servo release line 221 is cut off, and in this state, the forward clutch pressure is generated by the third DSV 123 and the engagement operation of the forward clutch 51 is started. Second accumulator 14
No effect of oil vibration reduction by No. 2 can be obtained.

In particular, in the case of the 4-2 shift, which is a so-called jumping shift, the amount of change in the turbine speed before and after the shift is 4-3.
Since the speed is larger than the speed change, and thus the speed change time is relatively long, the vibration due to the oil vibration is more easily perceived, and the trouble is increased.

Here, the forward clutch line 219
Is connected to the first accumulator 141 via the line 210 at the same time when the state of communication with the servo release line 221 is interrupted.
Is for pre-charging, in which hydraulic oil is stored in advance in the forward clutch line 219 exclusively in order to avoid a delay in the engagement operation of the forward clutch 51, and has a low set pressure and cannot be used for oil vibration prevention. is there. It is not preferable to newly provide an accumulator to reduce the oil vibration in the 4-2 shift when the power is turned off, because the size of the hydraulic control circuit increases and the cost increases.

Therefore, in this automatic shift control, in order to cope with such a problem, in steps S51 to S54 of the duty drive frequency determination, the power supply is controlled in a state where the oil temperature and the battery voltage are not respectively lower than the predetermined values. Only in the case of the 4-2 jump downshift at the time of off, a high frequency such as 83 Hz is selected as the drive frequency of the third DSV 123 in step S56. By increasing the drive frequency of the duty solenoid valve in this way, the degree of oil vibration in which the operating pressure rises and falls is reduced, and the occurrence of vibration is suppressed.

In this case, driving the duty solenoid valve at a high frequency affects the durability of the valve, so that the second accumulator 142 is operated as described above.
The drive of the third DSV 123 at such a high frequency is performed only in the case of the 4-2 jump downshift during power-off, in which the effect of reducing the oil vibration due to the above cannot be obtained, and the shift time is relatively long. Do it.

On the other hand, the second accumulator 1
In the case of a 4-3 downshift in power-off in which the effect of reducing the oil vibration by 42 cannot be obtained, the shift time is relatively short, and the trouble is relatively small.
The driving of the third DSV 123 at such a high frequency is not performed.

The reason why the high frequency is not selected at the low oil temperature is that the viscosity of the hydraulic oil becomes high at the low oil temperature and the oil vibration hardly occurs, so that it is not necessary to reduce the oil vibration. Further, the reason why the high frequency is not selected even at the time of low voltage is that it is difficult to drive the duty solenoid valve at the high frequency at the time of low voltage, and there is a possibility that the target operating pressure itself may not be generated. is there.

[0152]

As described above, according to the present invention, by controlling a solenoid valve that adjusts the operating pressure supplied to and discharged from a plurality of friction elements, the friction elements are selectively operated to achieve a target shift speed. Is automatically performed. In this case, the solenoid valve, which is controlled in the shift only when the shift is relatively long, in which oil vibration is easily felt, has a high drive frequency. In such a shift, the cycle of repeating the ON-OFF operation is shortened, thereby reducing the degree of oil vibration in which the operating pressure generated by the solenoid valve fluctuates,
Occurrence of vibration is suppressed.

Since the solenoid valve is not driven at such a high frequency at all times, but only during a shift with a long shift time, a reduction in the durability of the valve can be suppressed.

In particular, according to the second aspect of the invention, the solenoid valve is driven at a high frequency only when the accumulator is not provided in the oil passage between the solenoid valve and the friction element. When the accumulator can reduce oil vibration, the solenoid valve is not driven at a high frequency, which also suppresses a decrease in durability.

According to the third aspect of the present invention, since the solenoid valve is driven at a high frequency only when the oil temperature is higher than a predetermined value, the oil temperature is low and the viscosity of the hydraulic oil is high. When oil vibration is unlikely to occur, the solenoid valve is not driven at a high frequency, which also suppresses a decrease in durability.

Furthermore, in particular, according to the fourth invention, the solenoid valve is driven at a high frequency only when the voltage of the power supply for driving the solenoid valve is higher than a predetermined value. When it is difficult to drive the solenoid valve at a high frequency, and there is a possibility that the target operating pressure itself is not generated, the solenoid valve is not driven at a high frequency, which also suppresses a decrease in durability. .

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing a mechanical configuration of an automatic transmission according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of a transmission gear mechanism of the automatic transmission.

FIG. 3 is a circuit diagram of a hydraulic control circuit.

FIG. 4 is a sectional view showing a configuration of a hydraulic actuator of a 2-4 brake.

FIG. 5 is a control system diagram for each solenoid valve in the hydraulic control circuit.

6 is a main part enlarged circuit diagram showing a state of a first speed of the hydraulic control circuit of FIG. 3;

FIG. 7 is a main part enlarged circuit diagram showing a state of the second speed in the same manner.

FIG. 8 is an enlarged main part circuit diagram showing a state of the third speed in the same manner.

FIG. 9 is an enlarged circuit diagram of a main part showing a state of the fourth speed in the same manner.

FIG. 10 is a main part enlarged circuit diagram showing the state of the L range first speed.

FIG. 11 is an enlarged circuit diagram of a main part showing a state of a reverse speed in the same manner.

FIG. 12 is a main flowchart showing a control program for automatic shifting.

FIG. 13 is a flowchart of reading of an input signal of the same program and failure determination.

FIG. 14 is a flowchart of a failure determination of the turbine rotation sensor according to the same program.

FIG. 15 is a flowchart of a failure determination of an inhibitor switch in the same program.

FIG. 16 is a flowchart of a gear position determination of the same program.

FIG. 17 is a map diagram of a shift schedule for a D range.

FIG. 18 is a map diagram of a shift schedule for the S range.

FIG. 19 is a map diagram of an L range shift schedule.

FIG. 20 is a flowchart of the duty drive frequency determination of the program.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Automatic transmission 30, 40 Transmission gear mechanism 51-55 Friction element 56 One-way clutch 100 Hydraulic control circuit 121-123 Duty solenoid valve 300 Control unit 305 Turbine rotation sensor 311 Inhibitor switch

Claims (4)

[Claims] 1. A torque converter, a transmission gear mechanism,
A plurality of friction elements selectively operated by supply and discharge of operating pressure to switch a power transmission path of the gear mechanism; a hydraulic control circuit for supplying and discharging operating pressure to and from these friction elements; A target shift speed setting means for setting a target shift speed based on a driving state of the vehicle, having a solenoid valve for adjusting the operating pressure,
Control means for controlling the solenoid valve so that a shift to the target shift speed set by the setting means is performed. A control device for an automatic transmission, wherein a solenoid valve to be controlled in a shift is controlled by increasing a drive frequency only during a long shift. 2. The control device according to claim 1, wherein the control means increases the drive frequency and controls the solenoid valve only when the accumulator is not provided in the oil passage between the solenoid valve and the friction element. A control device for an automatic transmission according to the above. 3. An oil temperature detecting means for detecting the temperature of the hydraulic oil is provided, and the control means raises the driving frequency only when the oil temperature detected by the detecting means is higher than a predetermined value, thereby causing the solenoid valve to operate. The control device for an automatic transmission according to claim 1, wherein the control is performed. 4. A voltage detecting means for detecting a voltage of a power supply for driving the solenoid valve, wherein the control means increases the driving frequency only when the voltage detected by the detecting means is higher than a predetermined value. The control device for an automatic transmission according to any one of claims 1 to 3, wherein the solenoid valve is controlled by a solenoid valve.