JP2748369B2 - Hydraulic control device for belt-type continuously variable transmission for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial applications   The present invention relates to a hydraulic control device for a belt-type continuously variable transmission for a vehicle.
It is about. Background art   Provided on the primary and secondary rotation shafts respectively
Wound around a pair of variable pulleys
A transmission belt that is hung to transmit power;
A pair of primary hydraulics that change the effective diameter of the variable pulley
Equipped with actuator and secondary hydraulic actuator
A belt type continuously variable transmission for vehicles is known. For example
Belt-type continuously variable transmission described in JP-A-52-98861
The machine is that. Problems to be solved by the invention   By the way, the hydraulic pressure provided in the belt type continuously variable transmission
The control system includes the first line oil pressure and lower pressure
The second line hydraulic pressure is applied to one of the pair of hydraulic actuators and
Transmission that changes the speed ratio by acting on the other
A type having a valve device is conceivable. like this
In the hydraulic control device of the type, the output hydraulic
, In other words, the hydraulic pressure and the valve in a pair of hydraulic actuators
The operating position of the valve is
In a neutral state that is neither a deceleration
Introduces the low pressure side hydraulic actuator and the second line hydraulic pressure.
The oil passage on the low-pressure side.
The difference between the hydraulic pressure in the pressure actuator and the second line hydraulic pressure is large.
To determine the tension of the transmission belt.
The disadvantage is that the hydraulic pressure in the hydraulic actuator becomes unnecessarily large.
there were. Means to solve the problem   The present invention has been made in view of the above circumstances.
The purpose of this is to
Approximating the hydraulic pressure in the heater and the second line hydraulic pressure
As a result, the transmission belt tension is appropriately controlled.
To provide a hydraulic control device.   The purpose of the present invention to achieve such an object
Are provided on the primary rotation shaft and the secondary rotation shaft, respectively.
Transmission belt wound between a pair of variable pulleys
And a pair of oils that change the effective diameter of the pair of variable pulleys
Belt type continuously variable transmission for vehicles with pressure actuator
, The first line hydraulic pressure and the lower second hydraulic pressure
A pair of hydraulic actuators for line or drain pressure
Change the speed ratio by acting on one and the other
A hydraulic control device having a shift control valve device, (A) a throttle is provided, and the second line hydraulic pressure is reduced by the pair of
The shift acting on one of the hydraulic actuators
Independently of the oil passage via the control valve device, the pair of hydraulic
For guiding one of the actuators and the second line hydraulic pressure
A bypass oil passage connecting the second line oil passage, (B) the bypass oil provided in the bypass oil passage;
Acting on the road towards one of the hydraulic actuators
Operation allowing oil flow and heading to the second line oil passage
A check valve for preventing the flow of hydraulic oil, Is to include. Action and effect of the invention   Second line hydraulic pressure to one of a pair of hydraulic actuators
Independent of the oil passage through the shift control valve device
A pair of hydraulic actuators
One of the tutors is connected to the second line oil passage
Then, one of the hydraulic actuators was on the low pressure side
In this case, regardless of the operating position of the shift control valve device,
Pressure in the pressure actuator is close to the second line pressure
The tension of the transmission belt is controlled with high precision
And one of the pair of hydraulic actuators
When the pressure is high, the check valve closes the bypass oil passage.
Hydraulic actuation through the bypass oil passage
Hydraulic fluid leaks into the second line oil passage
Power consumption by increasing the power consumption of the
The speed of change is not reduced and shift response is not impaired.
No. That is, if there is no check valve as described above,
The throttle provided in the bypass passage has a pair of hydraulic actuators.
When one of the etas is on the low pressure side,
Add one hydraulic actuator hydraulic pressure and the second line hydraulic pressure
And a pair of hydraulic actuators
Prevents loss of hydraulic oil when one becomes high pressure side and
Suppressing the flow of hydraulic oil to improve shift response
It was necessary to have conflicting functions.
Not everybody was fully satisfied. Example   Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
I do.   In FIG. 2, the power of the engine 10 is locked up.
Fluid coupling with clutch 12, forward / reverse switching device 14, no belt type
Step transmission (hereinafter referred to as CVT) 16, intermediate gear device 18, and
And a drive wheel connected to a drive shaft 22 via a differential gear device 20
24.   The fluid coupling 12 is connected to the crankshaft 26 of the engine 10.
Pump 28 and the input shaft 30 of the forward / reverse switching device 14
Turbine rotated by oil from pump 28
And a lock fixed to the input shaft 30 via the damper 34
An up clutch 36 is provided. Lock up crack
The switch 36 is connected to the vehicle speed, the engine speed,
It is activated when the rotation speed of the bin 28 exceeds a predetermined value.
To connect the crankshaft 26 and the input shaft 30 directly.
is there.   The forward / reverse switching device 14 is a well-known double pinion type
The planetary gear mechanism, which is the input shaft of CVT16
Rotatable by carrier 42 fixed to output shaft 38)
A pair of planetary gears 44 and
And 46, the input shaft of the forward / reverse switching device 14 (the output of the fluid coupling 12)
Shaft) fixed to the shaft 30 and meshed with the planetary gear 44 on the inner peripheral side.
Ring gear that meshes with the ring gear 40 and the planetary gear 46 on the outer peripheral side.
48 and a reverse brake to stop the rotation of the ring gear 48.
And the input shaft of the carrier 42 and the forward / reverse switching device 14.
And a forward clutch 52 for coupling the forward clutch 30 with the forward clutch 30. Reverse
Brake 50 and forward clutch 52 are operated by hydraulic pressure
Frictional engagement devices of the type that are
In the disengaged state, the forward / reverse switching device 14 is in the neutral state.
Power transmission is interrupted. However, the forward clutch 52
When engaged, the output shaft 30 of the fluid coupling 12 and the CVT 16
The power shaft 38 is directly connected to transmit power in the vehicle forward direction.
You. When the reverse brake 50 is engaged, the fluid
Rotation direction between output shaft 30 of fitting 12 and input shaft 38 of CVT 16
Is inverted, so that the power in the vehicle backward direction is transmitted.   CVT 16 is installed on its input shaft 38 and output shaft 54, respectively.
Variable pulleys 56 and 58 of approximately the same diameter
A transmission belt 60 wound around pulleys 56 and 58;
I have. The variable pulleys 56 and 58 are connected to the input shaft 38 and the output shaft.
Fixed rotating bodies 62 and 64 respectively fixed to the force shaft 54,
Whether the input shaft 38 and the output shaft 54 can move in the axial direction respectively
The movable rotator 66 and the non-rotatable
And the movable rotating bodies 66 and 68 are hydraulic actuators.
With hydraulic cylinders 70 and 72 acting as eta
The V-groove width, that is, the conduction belt 60
Diameter (effective diameter) has been changed and the speed ratio e of CVT16
(= Rotation speed N of output shaft 54_out/ Rotation speed N of input shaft 38_in)
Has been changed. Variable pulleys 56 and 58
Are the same diameter, so the hydraulic cylinders 70 and 72 are similar
Pressure receiving area. Usually the hydraulic cylinder 70 and
Of the 72 that are located on the driven side, the clamping pressure is the conduction belt
Associated with a tension of 60. The oil pump 74 is oil
A hydraulic source of the pressure control circuit, comprising a fluid coupling
The clamp is integrally fixed to the 12 pumps 28,
The rotary shaft 26 is always driven to rotate.   FIG. 1 controls the vehicle power transmission device shown in FIG.
2 shows a hydraulic control circuit for performing the above. Oil pump 74
Reflux the hydraulic oil into the oil tank (not shown)
The first line oil passage 80 is sucked through the suction oil passage 76 and the suction oil passage 78.
To pump. In the present embodiment, the operation in the first line oil passage 80
1st pressure regulator 100 of oil overflow (relief) type
By suction oil passage 78 and lock-up clutch pressure oil passage
The first line hydraulic pressure Pl₁But
The pressure is adjusted. In addition, the second type of pressure reducing valve
The first line hydraulic pressure Pl is controlled by the pressure regulating valve 102._TwoIs decompressed
The second line hydraulic Pl_TwoCan be generated
ing.   First, the configuration of the second pressure regulating valve 102 will be described. Shown in FIG.
As described above, the second pressure regulating valve 102 is connected to the first line oil passage 80 and the second line oil passage 80.
Spool valve element 110 that opens and closes between line oil passage 82
Ring seat 112, return spring 114, plunger
It has 116. With the first land 118 of the spool valve 110
Between the second land 120 and the second line hydraulic pressure Pl_TwoFeeds
A chamber 124 that is introduced as a back pressure through the throttle 122 is provided.
And the spool valve 110 is connected to the second line hydraulic pressure Pl._TwoBy
Urged in the valve closing direction. Also, sp
Through the throttle 126 on the first land 118 side of the
A chamber 128 into which a speed specific pressure Pe described later is introduced is provided,
The spool valve 110 is urged in the valve closing direction by the speed specific pressure Pe.
It is supposed to be. In the second pressure regulating valve 102,
The urging force of the turn spring 114 in the valve opening direction
It is provided to the spool valve 110 via a port 112. Ma
In addition, a throttle pressure P described later is applied to the end face of the plunger 116._thMake
A chamber 130 is provided for use with the spool valve 1
10 is this throttle pressure P_thBiased in the valve opening direction
It has become. Therefore, the pressure receiving of the first land 118
Area A₁, The area of the cross section of the second land 120 is A_Two, Plunge
A 116_Three, The urging force of the return spring 114
Is W, the spool valve 110 satisfies the following equation (1).
Equilibrium position. That is, the spool valve
The child 110 is moved according to the equation (1).
And works in the first line oil passage 80 leading to the port 132a.
Fluid flows into the second line oil passage 82 through the port 132b.
Condition and the second line oil passage leading to port 132b
The hydraulic oil in 82 flows to the drain port 132c communicating with the drain.
Is repeated, and the second line hydraulic pressure Pl_TwoDeparts
They are born. The second line oil passage 82 is
Since the system is relatively closed, the second pressure regulating valve 102
Line pressure Pl₁Decompressing
The second line hydraulic Pl_TwoIs generated.   Pl_Two= (A_Three・ P_th+ W-A₁・ Pe) / (A_Two−A₁)                                         …… (1)   The first pressure regulating valve 100 is, as shown in FIG.
Child 140, spring seat 142, return spring 14
4. Equipped with a plunger 146. The spool valve 140 is
Port 148a and drain port communicating with the first line oil passage 80
It opens and closes between 148b and 148c.
The first line as feedback pressure is applied to the end face of the land 150.
Hydraulic pressure Pl₁The chamber 152 for operating the
The first line hydraulic pressure Pl₁By spoo
The valve 140 is biased in the valve opening direction.
The plunger 146 provided coaxially with the spool valve 140
Throttle pressure P between the first land 154 and the second land 156
_thA chamber 158 is provided for guiding
Selected by the switch valve 170 described later on the end face of the
Second line hydraulic pressure Pl_TwoAnd oil in the primary hydraulic cylinder 70
Pressure P_inChamber 160 for applying relatively high hydraulic pressure
Is provided. And return spring 144
The biasing force is applied in the valve closing direction via the spring seat 142.
Is attached to the dial valve 140. Therefore, the spool
The pressure receiving area of the first land 150 of the valve 140 is A_Four, Plunger 14
The area of the cross section of the second land 156 of No. 6 is A_FiveOf the plunger 146
The pressure receiving area of the first land 154 is A₆, Return spring 144
Assuming that the biasing force of the spool valve is W, the spool valve element 140 is given by
Are balanced at the position where That is,
Pool valve element 140 is moved according to equation (2)
As a result, the first line oil passage led to port 148a
Some of the hydraulic oil in 80 goes to drain ports 148b and 148c.
Spilled at the first line hydraulic pressure Pl₁Is regulated
It is.   Pl₁=     [(P_in or Pl_Two) ・ A₆+ P_th(A_Five−A₆) + W] / A_Four                                         …… (2)   Returning to FIG. 1, the throttle pressure P_thIs engine 10
Actual throttle valve opening θ at_thRepresents
Generated by the throttle valve opening detection valve 180.
You. Also, the speed specific pressure Pe represents the actual speed ratio of the CVT16.
This is generated by the speed ratio detection valve 182.
That is, the throttle valve opening detection valve 180 is not shown.
A cam 184 that rotates with the throttle valve,
Engage with the cam surface of the cam 184, and
A plunger 186 driven in the axial direction
Thrust from plunger 186 and
1 line hydraulic pressure Pl₁Position where the thrust from
The first line hydraulic pressure Pl₁Decompress the actual
Throttle opening θ_thThrottle pressure P corresponding to_thTo
And a spool valve element 190 to be generated. Fig. 5
Above throttle pressure P_thAnd throttle valve opening θ_thRelationship with
The first pressure regulating valve 100 through the oil passage 84,
2nd pressure regulating valve 102, limit valve 210, 3rd pressure regulating valve 220
Supplied.   Also, the speed ratio detection valve 182 is an input-side movable rotating body of the CVT16.
Slide only on displacement amount equal to the displacement amount in the axial direction by sliding on 66
A detection rod 192 that is moved in the axial direction, and the detection rod 192
A spring 194 that transmits an urging force corresponding to the position of
While receiving the urging force from the spring 194, the first
In hydraulic pressure Pl₁In a position where both thrusts are balanced
Change the discharge flow rate to the drain,
And a spool valve element 198. Therefore,
For example, when the speed ratio increases, the fixed rotor 6 on the input side of the CVT 16
When the movable rotating body 66 approaches (reduces the V-groove width) to 2,
The detection rod 192 is pushed. Therefore, the first line
Supplied from oil passage 80 through orifice 196 and
The flow rate of hydraulic oil discharged to the drain by the
Operation on the downstream side of the orifice 196
The hydraulic pressure is increased. This working oil pressure is the speed specific pressure Pe,
As shown in FIG. 6, the speed ratio e
Can be And the speed ratio thus generated
The pressure Pe is supplied through the oil passage 86 to the second pressure regulating valve 102 and the third pressure regulating valve 102.
Each is supplied to a valve 220.   Here, the limit valve 210 is connected to the plunger 212 and the split valve.
Thrust in the valve closing direction of the ring 214 and the valve closing method of the plunger 212
And a spool valve element 216 for receiving a thrust in the opposite direction. Step
Throttle pressure P to act on the end face of_th
Is provided, and the spool valve element 216 is
Thrust and throttle pressure P in the valve closing direction of the spring 214_th
The thrust in the valve closing direction of the plunger 212 based on the
The thrust in the valve opening direction based on the speed specific pressure Pe is received in the opposite direction.
The thrust in the valve opening direction based on the speed specific pressure Pe is
4 and the plunger 212 thrust in the valve closing direction
Open between 86 and drain. Thereby, the speed specific pressure Pe becomes
As shown in FIG. 6, the throttle valve opening θ_thRelated to
An increase above the upper limit is prevented. Soshi
Thus, as described above, the speed specific pressure Pe becomes the throttle valve opening θ_thAbout
As a result, the second pressure regulating valve 10
In the second step, the second laser controlled according to the equation (1) is used.
In hydraulic pressure Pl_TwoMeans that the speed ratio e is large as shown in FIG.
Throttle valve opening θ_thIs smaller,
The decline is prevented. That is, the low pressure is related to the speed ratio e.
Approximate to the ideal curve shown in Fig. 8 for the side line hydraulic pressure
Characteristics can be obtained only by the hydraulic circuit.
Electromagnetic pressure control controlled by microcomputer
The hydraulic circuit is significantly cheaper than when using a servo valve
There are advantages.   The third pressure regulating valve 220 is provided with a reverse
Rake 50 and forward clutch 52
Suitable third line hydraulic pressure Pl_ThreeIs generated. sand
That is, the third pressure regulating valve 220 is connected to the first line oil passage 80 and the third line
Spool valve 222 that opens and closes between the oil passage 88 and the spring
Seat 224, return spring 226, plunger 228
It has. First land 230 and second land of spool valve 222
Third line hydraulic pressure Pl between land 232_ThreeFeedback
A chamber 236 is provided which is introduced as a pressure through the throttle 234.
And the spool valve 222 is in the third line hydraulic pressure Pl._ThreeClosed by
It is designed to be biased in the valve direction. Also spool
On the first land 230 side of the valve 222, the speed is
A chamber 240 into which the specific pressure Pe is guided is provided, and a spool valve is provided.
So that it is urged in the valve closing direction by the speed specific pressure Pe of the element 222.
Has become. In the third pressure regulating valve 220, a return spr
The urging force of the ring 226 in the valve opening direction is applied via the spring seat 224.
And is provided to the spool valve 222. Also plan
Throttle pressure P on the end face of jaw 228_thChamber for working
242 are provided, and the spool valve 222
Pressure P_thBiased in the valve opening direction
You. Therefore, the third line hydraulic pressure Pl_ThreeIs given by the above equation (1)
From a similar equation, the speed specific pressure Pe and the throttle pressure P_thBased on
Therefore, the pressure is adjusted to the optimum value. With this optimal value
In the forward clutch 52 or the reverse brake 50
Ensures torque transmission without slippage
This is a necessary and sufficient value for   Third line hydraulic pressure Pl adjusted as described above_ThreeThe mani
Forward valve 52 or reverse by dual valve 250
For the vehicle brake 50. Sand
The manual valve 250 is provided with the shift lever 252 of the vehicle.
Equipped with a spool valve element 254 that is moved in connection with operation
Shift lever 252 is in the N (neutral) range
The third line hydraulic pressure Pl_ThreeSupply
No, but L (low), S (second), D (drive)
In the state of being operated to the range, the third line hydraulic pressure Pl_ThreeTo
It is supplied exclusively to the forward clutch 52 and at the same time
The oil is drained from the key 50 and it is operated to the R (reverse) range
3rd line hydraulic pressure Pl_ThreeExclusively for reverse brake 50
Oil from the forward clutch 52 at the same time
(Parking) Forward while operating in the range
Is drained from the clutch 52 and the reverse brake 50. What
Note that accumulators 256 and 258 loosen frictional engagement.
The forward clutch 52 and the forward clutch 52
And the reverse brake 50 respectively.   The first line hydraulic pressure P regulated by the first pressure regulating valve 100
l₁And the second line oil regulated by the second pressure regulating valve 102
Pressure Pl_TwoIs a shift control valve to adjust the speed ratio of CVT16
The hydraulic cylinder 70 and the hydraulic cylinder 72 are
It is supplied to one side and the other. Transmission control valve device
260 is composed of shift direction switching valve 262 and flow rate switching valve 264
Have been. Note that the shift direction switching valve 262 and the flow
Pilot pressure P for driving quantity switching valve 264_pIs a pyro
The pilot oil generated by the pressure control valve 266
It is guided by a road 90. Pilot suppression
The valve 266 is connected between the first line oil passage 80 and the pilot oil passage 90.
Spool valve element 268 that opens and closes, and this spool valve element 268
And a spring 270 for urging the valve in the valve opening direction.
Spool valve 268 is pilot pressure P_pBased on the valve closing direction
When the biasing force is balanced with the biasing force of the spring 270,
Moved to the first line oil passage Pl₁Depressurize
Constant pilot pressure P_pGenerate.   As shown in detail in FIG. 9, the shift direction switching valve 262 is
A spool valve controlled by the first solenoid valve 272.
And three first connection paths 2 connecting the flow rate switching valve 264
74, communicates with the second connection path 276 and the third connection path 278, respectively.
Ports 280a, 280c, 280e and drain port communicating with drain
280b and the first line hydraulic pressure Pl through the throttle 282.₁Is supplied
Port 280d and the second line hydraulic pressure Pl_TwoIs supplied
280f and one end of the moving stroke (the upper end in FIG. 9).
A certain first position and the other end of the movement stroke (the lower end in FIG. 9)
Is slidably disposed between the first position and the second position.
The pool valve element 284 and the spool valve element 284 are moved to the first position.
A spring 286 is provided for biasing. The above
Pilot hydraulic pressure P is provided on one end of pool valve 284._pBut
While always operating, the off state of the first solenoid valve 272
State, that is, in the closed state, the end on the other end side of the spool valve element 284.
Pilot hydraulic pressure P on the surface_pIs activated, but is in the ON state,
That is, in the open state, the pressure downstream of the throttle 288 is exhausted, and
Illot Hydraulic P_pIs inactive. Therefore, the first
While the magnetic valve 272 is on, the spool valve element 284 is in the second position.
Between the port 280a and the drain port 280b.
Between port 280d and port 280e
Between port 280c and port 280d, and port 280e
And the port 280f are opened, but the first solenoid valve 272 is turned off.
The spool valve 284 is in the first position during the
Between port 280a and drain port 280b, and
When opening between port 280e and port 280d respectively
Between port 280c and port 280d, and port 28
The space between 0e and port 280f is closed. Where the shifting direction
In the switching valve 262, as shown in FIG.
84 lands and each port 280a, 280c, 280e, 280b, 280d, 280
The spool valve element 284 is opened so that
Responsiveness is improved due to a shorter travel stroke
Have been. However, even in the above half-open state, the hydraulic oil flow
The flow cross-section is set so that sufficient
Even if the movement stroke is shortened as described above,
It doesn't matter.   The flow switching valve 264 is controlled by a second solenoid valve 290.
The three first connection paths 274,
Ports communicating with the second connection path 276 and the third connection path 278, respectively.
292b, 292d, 292f and the primary hydraulic cylinder 70
Port 292a and port 292c, and the secondary hydraulic cylinder
Port 292e communicating with port 72 and one end of the movement stroke
The first position (upper end in FIG. 9) and the other end of the movement stroke
Slidable between the second position (lower end in FIG. 9)
Spool valve element 294 and the spool valve element 2
A spring 296 for urging the 94 toward the first position.
I have. As with the shift direction switching valve 262, the spool
Pilot oil pressure P is provided on one end of valve 294._pAlways works
On the other hand, when the second solenoid valve 290 is in the off state,
Pilot hydraulic pressure P is applied to the other end of spool valve element 294._pBut
It works, but in the off state, that is, in the open state, the throttle
Pilot hydraulic pressure P is exhausted downstream from 298_pInaction
State. Therefore, the second solenoid valve 290 is turned on (due
Spool ratio 294 is second in the period of 100%
Between port 292a and port 292b.
Port 292c and port 292d, and port 292e and port 292c.
292f and the second solenoid valve
During the period when 290 is off (duty ratio 0%),
The valve 294 is positioned at the first position and the port 292a is
Port 292b, port 292c and port 292d, and
And between ports 292e and 292f are closed.
You. Note that during the period when the second solenoid valve 290 is off,
Port 292c and port 292d are closed,
Slightly through the throttle hole 300 formed in the spool valve element 294
They are in communication. And the primary hydraulic cylinder
70 is the above port via a primary side oil passage 302 having a throttle 304
292a and port 292c.
The Linda 72 is connected to the port 292e via the secondary oil passage 306.
Connected and equipped with a check valve with throttle 308
It is connected to the second line oil passage 82 via the path oil passage 309.
You. Also in this flow rate switching valve 264, the shift direction switching valve 262
Similarly, each land of spool valve element 294 and port 292a, 29
Open between 2b, 292c, 292d, 292e, 292f with half open
So that the movement stroke of the spool valve element 294 is shortened
ing.   Therefore, when the first solenoid valve 272 is on,
As shown by the solid line in FIG.
Oil is throttle 282, port 280d, port 280c, second connection path 27
6, port 292d, port 292c, primary oil passage 302, throttle 304
Through the primary hydraulic cylinder 70 while the secondary
The hydraulic oil in the side hydraulic cylinder 72 is supplied to the secondary
Port 292e, port 292f, third connection path 278, port 280e, port
The gas is discharged to the second line oil passage 82 through the port 280f. this
Therefore, the hydraulic oil (Pl₁) Is the primary oil
Pressure on the pressure cylinder 70 and the secondary hydraulic system
The hydraulic fluid (Pl_Two) Made
The primary hydraulic cylinder 70 and the secondary hydraulic
The thrust equilibrium with the cylinder 72 is lost, and the speed of the CVT16
The speed ratio e is changed in the speed increasing direction (speed ratio increasing direction).
You.   Conversely, when the first solenoid valve 272 is off, the ninth
As shown by the broken line in the figure, the hydraulic oil in the first line oil passage 80
Aperture 282, port 280d, port 280e, third connection path 278, port
Outlet 292f, port 292e, secondary oil passage 306
While flowing into the hydraulic cylinder 72, the primary hydraulic cylinder
Hydraulic oil in 70 is throttle 304, primary oil passage 302, port 292
a, port 292b, first connection path 274, port 280a, drain port
Drained through the drain 280b. Therefore, the first
Hydraulic oil (Pl₁) Is the secondary hydraulic cylinder 7
2 and the primary hydraulic cylinder 70
Pressure is applied to the primary hydraulic
The thrust between the cylinder 70 and the secondary hydraulic cylinder 72 is lost.
The speed ratio e of the CVT16 is reduced in the deceleration direction (speed ratio decreasing direction).
Direction).   As described above, the second solenoid valve 290 is turned on or off.
Connection between ports 292a and 292b,
Port 292c and port 292d, and port 292e and port 292c.
292f is opened or closed, respectively, and the ninth
As shown by the solid and broken lines in the figure, the flow rate of hydraulic oil
Since it is in the non-suppression state or the suppression state, the CVT16
The speed ratio e changes quickly in the deceleration direction or the acceleration direction.
Or it can be changed slowly. Also, the second solenoid valve 290
It is driven continuously on and off and its duty ratio is controlled.
The spool valve 294 is moved by the
Position in the middle of the
The changing speed of the speed ratio e of the CVT 16 is controlled. FIG.
The driving state and CV of the first solenoid valve 272 and the second solenoid valve 290
The relationship between the shifting direction of T16 and the changing speed of the speed ratio e is shown.
doing. Note that the first solenoid valve 272 is on and the second
When the solenoid valve 290 is off, the first line oil passage 80
Hydraulic oil flows through the throttle hole 300 of the spool valve element 294 on the primary side.
Supplied to the hydraulic cylinder 70, a gradual increase in speed is performed.
You.   The bypass oil passage 309 is provided from the secondary hydraulic cylinder 72.
Check valve with throttle 30 during speed-up shifting in which hydraulic oil is drained
No function since it is closed by 8. Also,
Even during normal deceleration shifting, the inside of the secondary hydraulic cylinder 72 remains
Become P_outIs the second line hydraulic pressure Pl_TwoHigher hydraulic pressure
Therefore, the bypass oil passage 309 is closed by the check valve 308 with the throttle.
Have been. However, the first solenoid valve 272 and the second solenoid valve 2
Both 90 are off and the flow switching valve 264 is closed
Is reached, the secondary-side hydraulic
While hydraulic oil is supplied into the drain 72, the primary hydraulic cylinder
From the inside of 70, work from the gap formed in the sliding part of the piston
CVT16 gently decelerates as hydraulic fluid gradually leaks
State. Thus, at the time of gentle deceleration shifting
Since the bypass oil passage 309 functions, the secondary hydraulic cylinder 7
To prevent the hydraulic oil from leaking from 2 to the second line oil passage 82.
There is no need to consider reducing the aperture
Desired speed ratio change speed during gentle deceleration shifting like
Work inside the secondary hydraulic cylinder 72 so that
Throttle check valve 308 to allow sufficient supply of hydraulic oil.
The diameter can be set relatively large.   Here, the first line hydraulic pressure Pl in CVT16₁A true drive
During dynamic running, as shown in Fig. 11,
At the time of parking travel, a hydraulic pressure value as shown in FIG. 12 is desired.
FIGS. 11 and 12 show the case where the input shaft 38 is fixed.
Speed ratio within the entire range while rotating at
It shows the required hydraulic pressure value when
You. In this embodiment, the primary hydraulic cylinder 70 and the secondary hydraulic
Since the pressure receiving areas of the cylinders 72 are the same,
During operation, the hydraulic pressure P in the primary hydraulic cylinder 70_in> Secondary oil
Hydraulic pressure P in pressure cylinder 72_out, Fig. 12 engine brake
P when running_out> P_inIn each case, the drive side hydraulic
The hydraulic pressure in the cylinder> the hydraulic pressure in the driven hydraulic cylinder. True drive
P above during dynamic running_inIs the drive side hydraulic cylinder
Because it generates force,
In order to generate the thrust to obtain the target speed ratio,
In order to reduce power loss, the first line hydraulic pressure Pl₁
Is the above P_inTo the value obtained by adding the necessary and sufficient margin oil pressure α
Pressing is desired. However, FIG. 11 and FIG.
First line hydraulic pressure Pl shown in the figure₁The oil in one hydraulic cylinder
It is not possible to regulate based on pressure,
In the present embodiment, the switch valve 170 is provided, and P_inAnd
And second line hydraulic pressure Pl_TwoThe higher oil pressure is the first key
The pressure is supplied to the pressure valve 100. This means
As shown in FIG. 13, P_inCurve and P_outCurve showing
At the time of no-load running where the first line hydraulic pressure Pl
₁P_inAnd P_out(≒ Second line hydraulic pressure Pl_Two) Whichever is higher
Required even when controlling to a value obtained by adding the margin value α to the hydraulic pressure value
It is.   The switch valve 170 connects the chamber 160 and the throttle 310 of the first pressure regulating valve 100 to each other.
And a common port 312 communicating with the primary oil passage 302
1st port 314 which communicates with the second line oil passage 82
The second port 316 and the common port 312 to the first port 31
Connect 1st position to connect with 4 and common port 312 to 2nd port 31
Spool moved between 6 and a second position to connect
The valve element 318 and the spool valve element 318 are moved toward the second position.
And a biasing spring 319. Above spool
The hydraulic pressure P in the primary hydraulic cylinder 70 is
_inAnd second line hydraulic pressure Pl_TwoAre each acted
And hydraulic pressure P_inAnd second line hydraulic pressure Pl_TwoHigh oil of
The pressure is moved to the side where the pressure is applied to the chamber 160 of the first pressure regulating valve 100.
Can be done. Strictly speaking, hydraulic pressure P_inThrust based on the second line
Hydraulic pressure Pl_TwoAnd the thrust of the spring 319
Hydraulic pressure P_inAct on chamber 160
However, the thrust of the spring 319 is extremely small.
You.   As described above, the primary hydraulic system is controlled by the switch valve 170.
Oil pressure P in Linda 70_inAnd second line hydraulic pressure Pl_TwoOf
High oil pressure is used as feedback oil pressure for the first pressure regulating valve 100.
Because it is made to act on the chamber 160, the first
In hydraulic pressure Pl₁Is, as shown in FIG._inOr Pl
_TwoP approximately equal to_outPressure higher than the margin α
You. Therefore, the first line hydraulic pressure Pl₁Is a necessary and sufficient value
And the power loss is made as small as possible. Cause
Next, the first line hydraulic pressure Pl indicated by a broken line in FIG.₁Is a switch
When the valve 170 is not provided, the speed ratio e
When the pressure is low, unnecessarily large excess hydraulic pressure is generated
I have.   This margin α is within the entire speed ratio change range of the CVT16.
And change the speed ratio at the desired speed to obtain the desired speed ratio.
This is a necessary and sufficient value, and is evident from equation (2).
Like, throttle pressure P_thIn relation to the first line hydraulic pressure P
l₁Has been raised. Pressure receiving of each part of the first pressure regulating valve 100
The area and bias of spring 144 are set accordingly.
It is being done. At this time, the pressure is regulated by the first pressure regulating valve 100.
Pressed first line hydraulic pressure Pl₁Is, as shown in FIG.
_inOr P_outAnd throttle pressure P_thIncreases with
But the throttle pressure P_thAt the maximum value corresponding to
It is made to be summed up. Thereby, the speed ratio e
Becomes the maximum value and the V groove width of the primary variable pulley 56 decreases.
In the mechanically blocked state, the primary hydraulic cylinder 70
Hydraulic P_inIs always higher by the margin α
Well controlled first line hydraulic pressure Pl₁Overpressure is prevented
It has become.   In the first pressure regulating valve 100 described above, the first line oil passage 80
The work that was discharged from the communicating port 148a to the port 148b
Fluid, and hydraulic fluid drained through throttle 320
Is locked by the clutch pressure regulating valve 322.
Pressure clutch suitable for actuating
H Hydraulic P_CLAnd the lock-up clutch pressure oil passage 92
Is to be led to. That is, the clutch
The pressure regulating valve 322 has a clutch hydraulic pressure P as a feedback pressure.
_CLSpool valve element 324 urged in the valve opening direction in response to the
The spring 3 for urging the spool valve element 324 in the valve closing direction
26, and the spool valve element 324 is
The thrust based on the lock pressure balances with the thrust of the spring 326
Actuated to operate the lock-up clutch pressure passage 92
By letting out the hydraulic oil inside, a certain amount of clutch oil
Pressure P_CLIs generated. Outflow from clutch pressure regulating valve 322
The applied oil is transmitted through the throttle 328 to the transmission
Is sent out for lubrication of each part of the
The oil is returned to the suction oil passage 78 of the pump 74.   Clutch hydraulic pressure P regulated as described above_CLIs
The engagement side oil passage 332 of the fluid coupling 12 is controlled by the
And the oil passage 334,
So that the clutch 36 is engaged and released.
Has become. That is, the lock-up control valve 330
Back-up clutch pressure oil passage 92 to the engagement side oil passage 332 and
Spool valve 336 that is alternatively connected to the oil passage 334
And a spring 338 for urging the spool valve element 336 toward the release side.
And At both ends of the spool valve element 336,
H Hydraulic P_CLAre respectively given. Therefore, the third
When solenoid valve 340 is off and closed
The spool valve 336 is released according to the spring 338
Side, and the lock-up clutch 36 is released.
It is said. The lock-up control valve 330 shown in FIG.
Is shown. However, the third solenoid valve 340 is turned on.
To release the pressure downstream of the throttle 342.
Then, the spring 338 side of the spool valve element 336 until then
The clutch hydraulic pressure P that was applied to the chamber 344_CLIs removed
The spool valve element 336 resists the biasing force of the spring 338
Moved to the engagement side, lock-up clutch 36 is engaged
State. The lock-up control valve 330
The hydraulic fluid is sent to the cooler.
The hydraulic oil pressure is controlled by the cooler bypass valve 346.
Is controlled. 348 is the first line hydraulic pressure Pl₁Prevents excessive pressure rise
It is a safety valve to stop.   In FIG. 2, the electronic control unit 350 is a control system according to this embodiment.
It functions as a control means, and the hydraulic control shown in FIG.
The first solenoid valve 272, the second solenoid valve 290, the third solenoid in the circuit
By driving the valve 340, the speed ratio e of the CVT 16 and the fluid connection
The hand 12 controls the lock-up clutch 36. Electronic control
The device 350 is a so-called microcontroller including a CPU, a RAM, a ROM, and the like.
Computer, which includes the engine speed
Engine circuit sensor 352 for detection, CVT16 input shaft
Input shaft rotation sensor 354, C for detecting the rotation speed of 38
Output shaft rotation to detect the rotation speed of output shaft 54 of VT16
The sensor 356 and the slot provided in the intake pipe of the engine 10
Throttle valve opening sensor for detecting the opening of the toll valve
358, operation to detect the operating position of shift lever 252
From the position sensor 360, the engine speed N_eA signal representing
Input shaft rotation speed N_in, The output shaft rotation speed N_outTo
Signal, throttle valve opening θ_thSignal representing shift
Operation position P of bar 252_sAre supplied, respectively.
You. The CPU in electronic control unit 350 uses the temporary storage function of RAM.
Input according to the program stored in ROM while using
The signal is processed, and the first solenoid valve 272, the second solenoid valve 290, the third
A signal for driving the magnetic valve 340 is output.   In the electronic control device 350, a main
The initialization is performed by executing
Input signals from each sensor are read into the
The rotation speed N of the input shaft 38 based on the read signal_in,
Rotation speed N of output shaft 54_out, CVT16 speed ratio e, vehicle speed v, etc.
Is calculated and locked up according to the input signal condition.
Control, CVT16 shift control, etc. are performed sequentially or selectively.
Is performed.   In the speed change control of the CVT 16 described above, for example,
It is controlled according to the flowchart. Step S1
When input signals from each sensor are read,
The engine 10 times based on that read signal
Rolling speed N_e, The rotation speed N of the input shaft 38_in, The rotation speed of the output shaft 54
Degree N_out, Throttle valve opening θ_thIs calculated, and step S2
At which the speed ratio e of CVT16 (= N_out/
N_in), Vehicle speed v and the like are calculated. In step S3
The minimum fuel efficiency and drivability of the engine 10.
From the relationship previously determined, the throttle valve opening θ_th
Target speed ratio e based on the vehicle speed v^*Is determined.
This relationship is, for example, the throttle valve opening θ_thRequest represented by
To generate output on the minimum fuel efficiency curve of engine 10
From the above relationship, the vehicle speed v and the throttle valve
Opening θ_thEngine speed uniquely determined based on
Degree (input shaft rotation speed) is the target rotation speed N_in ^*And this
N_in ^*Target speed ratio e to achieve the value^*Is determined
It is. Note that the above relationship is based on the function formula or data map.
It is stored in advance in the ROM in the form. Also, the above relationship
Are stored in advance, and the operation of the shift lever 252 is
It is selected based on the working position (D, S)
You.   Then, in step S5, the value obtained in step S4
Control deviation (e^*-E) is positive or not.
And the control deviation (e^*−e)
Step S5a or S5b for changing the speed ratio e is executed.
Is performed. If the determination in step S5 is affirmative,
In step S5a, the first solenoid valve 272 is turned on.
Speed-up shift of CVT16 is executed and actual speed ratio e increases
Let me do. However, the decision in step S5 was denied
In this case, the first solenoid valve 272 is turned off in step S5b.
The CVT16 deceleration shift is executed and the actual speed
The ratio e is reduced.   In step S6, the flow control value V₀Is, for example, the following equation (3)
Is required in accordance with     V₀＝ k ・ | e^*−e | …… (3)   In step S7, the flow control value V₀Is output
Thus, the second solenoid valve 290 is driven. This flow control value V₀flag
For example, it corresponds to the duty ratio, and
Duty ratio changes continuously at the specified duty frequency
The driven signal is supplied to the second solenoid valve 290. Soshi
Therefore, the above steps are executed repeatedly
As a result, the speed ratio e of the CVT 16 is
It is controlled to an appropriate value.   In the lock-up clutch control (not shown), the vehicle
The speed v is a predetermined constant value, for example, 30 km / h or more.
The lock-up clutch 36 is engaged
You.   As described above, according to the present embodiment, the secondary hydraulic cylinder
A check valve 308 with a throttle is provided between the nozzle 72 and the second line oil passage 82.
A bypass oil passage 309 is provided.
The oil passage 309 extends from the second line oil passage 82 to the secondary hydraulic cylinder 7.
2 when the flow of hydraulic fluid occurs,
Opened during kana deceleration shifting. For this reason, the secondary hydraulic pressure
Oil pressure P in cylinder 72_outAnd second line hydraulic pressure Pl_TwoOriginally
In the closed state of the flow switching valve 264 that is easily dissociated,
Hydraulic pressure P in the secondary hydraulic cylinder 72_outAnd second line hydraulic
Pl_TwoIs approximated by the second pressure regulating valve 102.
Belt tension can be controlled with high precision.   Also, according to the present embodiment, only during slow deceleration shifting
In this case, the bypass oil passage 309 is opened.
09, the hydraulic oil in the secondary hydraulic cylinder 72
Leakage to the oil passage 82 to increase the consumption of hydraulic oil
Increase power loss or reduce speed ratio change speed.
Therefore, it is possible to prevent the shift response from being impaired. Conversely
By reducing the throttle of the bypass passage 309,
When the secondary hydraulic cylinder 72 becomes low pressure, the secondary oil
Hydraulic pressure P in pressure cylinder 72_outAnd second line hydraulic pressure Pl_TwoApproximation to
Is not impaired. That is, the check valve with throttle 308
If there is no non-return function of
The secondary hydraulic cylinder 72 is now on the low pressure side
Sometimes the flow rate of hydraulic oil is reduced to
Hydraulic pressure and second line hydraulic pressure Pl_TwoAnd at the same time
Hydraulic oil loss when the secondary hydraulic cylinder 72 is on the high pressure side
Hydraulic oil distribution to prevent loss and improve shift response
Contradictory function of suppressing
And both functions were not always fully satisfied
It is.   Moreover, according to the present embodiment, it is possible to reduce
From the second line oil passage 82 into the secondary hydraulic cylinder 72.
Since hydraulic oil is supplied, the seal of the secondary hydraulic cylinder 72 is
The transmission belt 60 slips even if
The trouble does not occur.   The embodiment of the present invention has been described with reference to the drawings.
However, the present invention is applied in other aspects.   For example, in the above-described embodiment, the check valve with throttle 308
May be provided with a throttle and a check valve in series.
It is. At this time, instead of the aperture,
The diameter of the bypass oil passage 309 should be
And length.   In the above-described embodiment, the bypass oil passage 309 is connected to the secondary side.
Provided between the hydraulic cylinder 72 and the second line oil passage 82
Belt tension control during slow deceleration shifting.
Was easier, but instead or
In addition, the primary hydraulic cylinder 70 and the second line oil passage 82
In the meantime, when the primary hydraulic cylinder 70
Even if a bypass oil passage closed by a stop valve is provided
It is good.   In the above-described embodiment, the throttle valve opening detection valve 18
Throttle pressure P generated by 0_thIs used
Like a vehicle with a diesel engine
For vehicles that do not use a throttle valve for the
A hydraulic pressure corresponding to the dull operation amount may be used. like this
For example, if the cam 184 of the above-described embodiment is
The accelerator pedal rotates as the pedal is depressed.
It may be mechanically related to Dal.   Further, in the shift control of the CVT 16 in the above-described embodiment,
Target speed ratio e^*Speed so that the actual speed ratio e matches
The ratio e is controlled so as to be adjusted.
N_in ^*Is the actual input shaft rotation speed N_inControl to match
It may be done.   In the above-described embodiment, the pilot pressure control valve 26
Pilot pressure P generated by 6_pReplace with
And clutch hydraulic pressure P_CLMay be used. In this case pie
No need for lot pressure control valve 266, making the hydraulic circuit cheaper
Can be configured.   In the above-described embodiment, the input of the fluid coupling 12 and the input of the CVT 16 are performed.
The forward / reverse switching position 14 was provided between the shaft 38 and the
It is provided between the output shaft 54 of T16 and the intermediate gear device 18.
It may be.   Also, instead of the fluid coupling 12 of the above-described embodiment, an electromagnetic
Other types of couplings, such as clutches, wet clutches, etc.
You.   The above is merely an example of the present invention.
Therefore, the present invention may be variously modified without departing from the spirit thereof.
Further modifications can be made.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing a hydraulic control device for operating the device shown in FIG. 2 in detail. FIG. 2 is a skeleton view showing a power transmission device provided in a vehicle according to one embodiment of the present invention.
FIG. 3 is a diagram showing the second pressure regulating valve of FIG. 1 in detail. FIG. 4 is a diagram showing the first pressure regulating valve of FIG. 1 in detail. Fifth
The figure shows the output characteristics of the throttle valve opening detection valve of FIG. FIG. 6 is a diagram showing output characteristics of the speed ratio detection valve of FIG. FIG. 7 is a diagram showing output characteristics of the second pressure regulating valve of FIG. FIG. 8 is a diagram showing ideal characteristics of the second line hydraulic pressure. FIG. 9 is a diagram showing the configuration of the transmission control valve device of FIG. 1 in detail. FIG. 10 is a view for explaining the relationship between the operating state of the first solenoid valve and the second solenoid valve in the shift control valve device of FIG. 9 and the shift state of the CVT of FIG. 11, 12, and 13 are diagrams for explaining the relationship between the speed ratio of the CVT of FIG. 2 and the hydraulic pressure of each part. FIG. 11 shows a positive torque running state, and FIG. FIG. 13 is a diagram showing an engine brake running state, and FIG. 13 is a diagram showing a no-load running state.
FIG. 14 is a diagram showing output characteristics of the first pressure regulating valve of FIG. 4 with respect to the hydraulic pressure in the primary hydraulic cylinder or the second line hydraulic pressure. FIG. 15 is a flowchart illustrating the operation of the control device in FIG. 16: CVT (belt-type continuously variable transmission) 56, 58: Variable pulley 60: Transmission belt 70, 72: Hydraulic cylinder (hydraulic actuator) 260: Transmission control valve device 308: Check valve with throttle (throttle and check valve) ) 309: Bypass oilway

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Susumu Okawa               1 Toyota Town, Toyota City, Aichi Prefecture               Dosha Co., Ltd.                (56) References JP-A-59-99161 (JP, A)                 JP-A-61-88063 (JP, A)

Claims (1)

(57) [Claims] A vehicle including a transmission belt wound around a pair of variable pulleys provided on the primary rotation shaft and the secondary rotation shaft, respectively, and a pair of hydraulic actuators for changing an effective diameter of the pair of variable pulleys. In a belt-type continuously variable transmission, a shift control valve device that changes a speed ratio by applying a first line hydraulic pressure and a second line hydraulic pressure or a drain pressure lower than the first line hydraulic pressure to one and the other of the pair of hydraulic actuators is provided. A hydraulic control device having a throttle, independently of an oil passage via the shift control valve device for applying the second line hydraulic pressure to one of the pair of hydraulic actuators. A bypass oil passage connecting one of the first oil passage and a second line oil passage for leading the second line oil pressure; and a bypass oil passage provided in the bypass oil passage. A check valve that allows the flow of hydraulic oil toward one of the hydraulic actuators and prevents the flow of hydraulic oil toward the second line oil passage. Hydraulic control device for step transmission.