JPS612958A - Hydraulic controller for power transmission gear with continuously variable transmission - Google Patents

Abstract

PURPOSE:To prevent a belt from being slipped and increased to have excessive tensile force by increasing controlling line pressure of a continuously variable transmission (CVT) only while a sub speed changing gear is being operated. CONSTITUTION:The controlling line pressure increasing means of CVT1 consists of both a speed changing ratio detecting valve which generates a speed changing ratio pressure, acting as a function of reducing speed changing ratio of CVT, and a generating valve for line pressure acting as a function of reducing speed changing ratio pressure. Since line pressure in CVT is held at a normal value while a sub speed changing gear 42 is not in operation, the tensile force of the belt of CVT will not be increased excessively. On the other hand, while the sub speed changing gear is in operation, the line pressure of CVT will be increased and the belt of CVT therefore be prevented from slipping, on account of which shifting operation of the sub speed changing gear may be performed appropriately.

Description

Detailed Description of the Invention Technical Field The present invention relates to a continuously variable transmission fi (CV) used in a vehicle.
The present invention relates to a hydraulic control device for a power transmission device with T).

As an example of the prior art, in the power transmission device with a CVT disclosed in Japanese Patent Application No. 58-144985, an auxiliary transmission is used to switch the vehicle between forward and backward movement and to improve driving performance.

However, in a power transmission system with a CVT, no prior art has been found that discloses automatically switching an auxiliary transmission between a low gear and a high gear during 14 or D range.

When the auxiliary transmission is upshifted, an additional torque corresponding to the inertia torque is applied to the power transmission system on the input side of the auxiliary transmission in order to reduce the rotation of the input side of the auxiliary transmission.

Also, when the auxiliary transmission is downshifted, if the low-speed frictional engagement device engages too early or too late, the auxiliary transmission will not shift until the rotation on the input side of the auxiliary transmission reaches a steady value. The power transmission system on the input side of the machine has tI! I+′l: An additional torque corresponding to the torque is applied.

Therefore, if the CVT line pressure is not set taking into consideration the shift of the auxiliary transmission, the CVT line pressure will
The belt becomes stiff, resulting in a 1-1 problem in durability. However, if the line pressure of the CVT is set high considering the shifting of the auxiliary transmission, the CVT
line pressure becomes excessive, belt tension is too high, reducing durability, increasing drive loss of the oil pump,
Therefore, there is a problem of deterioration of the fuel portion lI ratio.

Purpose An object of the present invention is to provide a hydraulic control device for a power transmission device with a CVT that can maintain good CVT durability and fuel consumption without causing any trouble during gear shifting of an auxiliary transmission. .

Structure In order to achieve this object, the present invention provides a power transmission device with a CVT in which a stepless reduction coupling and an auxiliary fluid coupling for controlling a plurality of forward gears are provided in series in the power transmission path of an engine. A hydraulic control device includes a detection means for detecting a shift period of the auxiliary transmission, and a C during the shift period of the auxiliary transmission in response to the output of the detection means.
A line pressure increasing means for increasing the line pressure of vT is provided.

Effect Since the CVT line pressure is set to a normal value during the non-shift period of the auxiliary transmission, this prevents the CVT belt tension from becoming excessive and causing problems in durability and fuel consumption. I get hit.

・During the shift period of the No.j1 auxiliary transmission, line 1 of the CVT
Since the height increases by 1, it prevents the CVT belt from breaking down.
1, and the auxiliary transmission can appropriately shift gears.

Preferably, the line pressure -1 increase means is a gear ratio detection valve that generates a gear ratio pressure as a decreasing function of the gear ratio of the CVT;
A line pressure generation valve that generates line pressure as a decreasing function for gear shift output, and a line pressure generation valve that supplies gear ratio pressure to the line pressure generator 11'' valve.
fll): a cut-off valve for turning off the pulp, and a starvation means for placing the cut-off pulp in a blocking position.

In order to reduce the impact on the power transmission system when shifting the auxiliary transmission, the lock-up clutch in parallel with the fluid transmission device (hydraulic coupling or fluid torque converter) is held in a released state during the shifting period of the auxiliary transmission. Ru. In a daily implementation, this lock-up clutch control solenoid valve is utilized. That is, this solenoid valve is also used as a control means for the line pressure increasing means, and is also used to control the discharge of the control pressure of the cut-off valve. Therefore, there is no need to newly provide a solenoid valve, and an increase in the number of parts can be prevented.

Example An example of the non-explosion January will be described with reference to the drawings.

In FIG. 1, CVTI is a pair of input pulleys 2a,
It is provided with a 2bXl pair of output side pulleys 4a + 4b1 and a belt 6 that is hung between the input and output side pulleys and transmits engine power. One input-side pulley 2a is provided on the input shaft 8 so as to be movable in the axial direction but fixed in the rotational direction, and the other input-side pulley 2b is fixed to the input shaft 8.

Further, one output side pulley 4a is fixed to the output shaft 10,
The other output pulley 4b is provided on the output shaft 1o so as to be movable in the axial direction but fixed in the rotational direction. Opposing surfaces of input pulleys 2a and 2b and output pulley 4a,
The opposing surfaces of the belts 4b are formed in a tapered shape such that the distance between them increases toward the outside in the radial direction, and the cross section of the belt 6 is formed in the shape of an isosceles trapezoid. Output ■Repulley 4a, 4b
The pressing force of the input side pulleys 2a+2b is controlled to the minimum value that can avoid slipping of the belt 6 and ensure power transmission, and the pressing force of the input side pulleys 2a+2b is determined by the gear ratio T of the CVT l (=rotational speed Nin of the input shaft 8/output The rotational speed Nout) of the shaft 10 is determined. The fluid coupling 12 includes a pump 16 connected to the crankshaft 14 of the engine, and a turbine 18 fixed to the input shaft 8 and rotated by oil from the pump 16. Direct clutch 2
2 controls the connection between the crankshaft 14 and the input shaft 8;
The damper 24 absorbs the impact and engine torque fluctuation when the direct coupling clutch is switched from the disengaged state to the engaged state. When the vehicle speed or engine rotation speed reaches the predetermined value 1-,
The direct coupling clutch 22 is held in an engaged state, and the fluid coupling 1
The oil pump 26 rotates integrally with the pump 16 and supplies oil to the CVT I and fluid coupling 12 via the hydraulic control device.
etc. The counter shaft 28 is the output shaft 10 of the CVT l.
and has two gear wheels 30, 32. The engine power of the output shaft 10 is transmitted from the gear 34 coaxial with the output shaft 10 to the differential gear 36 via the counter shaft 28 - the second gear 30.32, and further from the differential gear 36 to the IF and the right axle. It is sent via shafts 38, 40 to the left and right drive shafts. Auxiliary transmission 42 is the output shaft of CVT I]
It is provided coaxially with respect to 0. The auxiliary transmission 42 includes a Ravigneau type compound planetary gear set 43, and this planetary gear set fl143 includes first and second sun gears 44, 46, and a first planetary gear 48 that meshes with the first sun gear 44.
, this first planetary gear 48 and second sun gear 46
A second planetary gear 50 meshes with the first planetary gear 48, a ring gear 52 meshes with the first planetary gear 48, and a carrier 54 rotatably supports the first and second planetary gears 48,50. The second sun gear 46 is connected to a shaft 64 which is integral with the output shaft 10 of the CVTl as an input part of the auxiliary transmission va 42, and the carrier 54 is connected to the gear 34. The high speed clutch 56 is connected to the shaft 64
The low speed brake 58 controls the fixation of the first sun gear 44, and the reverse brake 60 controls the fixation of the ring gear 52.

FIG. 2 shows the operating state of each friction engagement element of the auxiliary transmission 42 and the reduction ratio in each range. ◯ means an engaged state, × means a released state, and ρ1 and p2 are defined from the following equation.

p + == Zsl / Zr p2 = Zs2 / Zr where Zsl is the number of teeth of the first sun gear 44 , Zs2 is the number of teeth of the second sun gear 46 , and zr is the number of teeth of the ring gear 52 . That is, 17. In the low gear position of the D range, the first sun gear 44 is fixed by the low gear brake 58, so engine power is transmitted at a reduction ratio of 1+ρ142. D
In the high-speed range, the high-speed clutch 56 is engaged and the planetary gear unit 43 rotates as a unit, thereby transmitting engine power at a reduction ratio of 1. Since the ring gear 52 is fixed, engine power is transmitted through reverse rotation with a reduction ratio of 1-1/p2.

3 to 5 are detailed views of the hydraulic control device. The oil pump 26 pressurizes the oil sucked in through the strainer 72 and supplies it to the line pressure oil path 74. The throttle valve 76 generates a throttle pressure Pth related to the intake throttle opening degree 0 at the output port door 8. The spool 77 of the throttle valve 76 receives an acting force that increases as the throttle opening degree O increases from the throttle cam 79 and a throttle pressure pth as a feedback pressure from the control boat 81, opposingly. Controls the connection with the output port door 8. The manual valve 80 is located at 1. of the shift lever. (r+ -), D (drive)
, N (neutral), R (reverse), and P (parking) range, the axial position is controlled in relation to the first line pressure PI of the line pressure oil passage 74! I to boat 83 when in R range, l to boat 85 when in range, D
When in the range, they lead to boats 85 and 87, respectively.

The relief valve 89 controls the first line pressure P7 of the line pressure oil passage 74! ! It functions as a safety valve that releases oil in the line pressure oil passage 74 when the line pressure oil passage 74 exceeds a predetermined value.

The secondary hydraulic oil passage 82 has an orifice 84 and a boat 8 where excess oil from the primary regulator valve 198 is discharged.
5, and the secondary pressure regulator valve 86 is connected to the line pressure oil passage 74 via the orifice 88.
A control chamber 90 connected to the secondary hydraulic fluid line 82 via
It controls the connection between the secondary hydraulic oil passage 82 and the boat 94 in relation to the oil pressure in the control room 90 and the load on the spring 92, and controls the secondary oil pressure Pz of the secondary oil oil passage 82 to a predetermined value. to be maintained. The oil passage 95 is connected to the secondary hydraulic oil passage 82 via a boat 94 or an orifice 97. Lockup control valve 96 selectively connects secondary hydraulic oil passage 82 to the engagement side and disengagement side of lockup clutch 22 parallel to hydraulic clutch 12 . The solenoid valve 100 controls the connection between the control chamber 102 of the lock-up control valve 96 and the drain 104, and when the S solenoid valve 100 is off (non-energized), the secondary hydraulic fluid path 82 is connected to the release side of the lock-up clutch 98.
The secondary hydraulic pressure Pz from
In the case of
transmitted via. Cooler bypass valve 107 controls cooler pressure.

The gear ratio control device Ft108 includes first and second spool valves 110, 112, and first and second solenoid valves 114.
．． It is equipped with 116. During the period when the first solenoid valve 114 is off, the spool of the first spool valve 110 is in the chamber 117.
is suppressed toward the spring 118 by the secondary hydraulic pressure Pz of the boat No. 9, the first line pressure PI! I is connected to the second spool valve 1 via the boat 120 of the first spool valve 110
Sent to 12 boats + 22, boats + 24 and drain 1
The connection with 26 has been severed. During the period when the first solenoid valve 114 is on, the oil pressure in the chamber +17 is discharged through the drain 128 of the first solenoid valve 114, and the first spool
The spool of the boat 120 is pressed toward the chamber 117 by the spring 118, and there is no line pressure PA' on the boat 120.
24 is connected to drain 126. Further, during the period when the second solenoid valve 116 is off, the spool of the second spool valve 112 is pressed toward the spring 130 by the hydraulic pressure P2 of the chamber 128, and the connection between the boat 122 and the boat 132 is cut off. , boat 134 is connected to (+3) boat +36. Boat 132.134
is connected to the input hydraulic cylinder of the CVT l via an oil passage 138. During the period when the second sei valve 116 is on, the spool of the second spool valve 112 is
is pushed toward chamber 128, connecting boat 122 to boat 132 and disconnecting boats 134 and 136. Boat 136 is connected to boat 124 via oil line 142.

Orifice 140 directs a small amount of oil from boat 122 to boat 132 when second solenoid valve 116 is off. Therefore, the first solenoid valve +14 is off and the second solenoid valve 1
16 is on, oil is quickly supplied to the input side hydraulic cylinder of CVT l, and the gear ratio T decreases.

During the period when the first solenoid valve +14 is off and the second solenoid valve 116 is off, oil is supplied to the input hydraulic cylinder of the CVT I through the orifice +40.
The gear ratio T of VT1 gradually decreases. When the first solenoid valve 114 is on and the second solenoid valve 116 is on, oil is supplied to and discharged from the input hydraulic cylinder of the CVT I. held constant. During the period when the first electromagnetic valve 114 is on and the second electromagnetic well 6 is off, the oil in the input hydraulic cylinder 46 is discharged from the drain 126, so that the CVT l
The speed change technology increases rapidly.

The gear ratio detection valve +46 is shown in detail in FIG. Sleeves 148, 150 are coaxially disposed within valve bore 152 and are axially secured by snap rings 154. A rod 156 passes through the end of the sleeve 148 and has a spring seat 158 secured thereto.

Another rod 160 is coupled at both ends to the input movable pulley 2a and the rod 156, respectively, and moves the rod 156 in the axial direction by a displacement equal to the axial displacement of the input movable pulley 2a. Spool +62 is land 164.
166 and is fitted within the sleeve 150 at the same time as it moves in the axial force direction.

Land +64 is the space 16 between land +64 and 166
8 to the oil chamber 170, and the land 166 is a space! Boat 174 of sleeve 150 to 68
control the aperture area. Boat 174 is sleeve +48
It is connected to a drain 176 through a space around the outer periphery of the drain 176.

The oil chamber 170 has an output port 178 that generates a control pressure Pc, and the output port 178 is connected to the line pressure oil passage 74 via an orifice 180. The spring 182 is provided between the spring receiver 158 and the sleeve 150 and is connected to the rod +56.
The spring 184
The spring is provided between the spring receiver 158 and the flange 186 of the spool 162 to bias the spool 162 toward the oil chamber 170. As the amount of displacement of the input movable pulley 2a of the CVT 1 with respect to the input fixed pulley 32 increases, the lower gear ratio increases. Since the rod 156 is pushed out of the sleeve 148 due to an increase in the amount of displacement of the input movable pulley 2a, the urging force on the spool 162 by the spring 184 in the direction of the oil chamber 170 is reduced.

As a result, the spool 162 moves toward the rod +56, and the land 166 increases the opening area of the boat 174 to increase the oil discharge flow, so that the gear ratio pressure of the output coupler 1-178 decreases. . Gear specific pressure P■ is output port +7
Since it is generated by controlling the discharge amount of the hydraulic medium in step 8, the upper limit is defined as the line pressure I)l. The broken lines in FIGS. 7 and 8 illustrate two relationships between the gear ratio pressure and the gear ratio T. As will be described later, the first line pressure P
I! l decreases as the gear ratio decreases, but the gear ratio lower 1 at which the gear ratio pressure r1 becomes equal to the line pressure pH (this gear ratio lower l is the throttle pressure Pth, and therefore the engine torque T
It is a function of e. ), in the gear ratio range below that, P7=PI! It becomes 1. Note that in FIGS. 7 and 8, the double-dashed line is the ideal value of the first line pressure P/I, and T1>T2.

The cut-off valve 190 has a chamber 19 that communicates with the control chamber +02 of the lock-up control valve 96 via an oil passage 192.
4, and a spool 196 that moves in relation to the oil pressure of the chamber 194 and the spring force of the spring 195;
If it is off, that is, the lock-up clutch 22
is in the released state (when the auxiliary transmission 42 changes gears, (T7) the lock-up clutch 22 is released in order to absorb the shock of the power transmission system), the lock-up clutch 22 is in the closed state and the gear ratio is changed. The pressure difference is transmitted to the primary regulator valve +98.

The primary regulator valve +98 as a first line pressure generating means has a boat 1 to 200 supplied with the throttle pressure pth, a boat 202 supplied with the gear ratio pressure,
A boat 204 connected to the line pressure oil path 74, a boat 206 connected to the suction side of the oil pump 26,
and the first line pressure PA! via orifice 208!
A ball h210 is supplied with I, a spool 212 moves in the axial direction to control the connection between the balls 1 to 204 and the boat 206, and a spool 2 receives the throttle pressure pth.
12 toward the boat 202, and a spring 216 biasing the spool 212 toward the boat 202. The area of the two lands from the bottom of the spool 212 is AI, A2, the area of the land of spool 2+4 that receives the throttle pressure Pth is A3, and the area of the land of the spool 212 is A3.
When the acting force of 16 is defined as wl, the following equation holds true.

If the cut-off valve +90 is open and the gear ratio pressure is coming to the boat 202, PA'l = (A3・Pth+Wl−AI・Pr)/
(A2-All-, (+) If the cutoff valve 190 is closed and the boat 202 does not have the correct gear ratio, then P/!I = (A3・Pth +Wl) / (A2
-AI) ...(2) Note that formula (1) and (
P/l defined by formula 2) is shown by a solid line and a dashed-dotted line in FIGS. 7 and 8, respectively.

The sub-primary regulator valve 220 as a second line pressure generating means inputs the first line pressure P/l from the input boat 222 which is guided from the boat 85 of the manual valve 80 in the L and D ranges, and the second line pressure PA! 2, a boat 226 to which the gear ratio positive amount is introduced, and a second line pressure Pj as a feedback pressure.
! ! 2 through orifice 228
0, a spool 232 that controls the connection between the input boat 222 and the output port 224, a boat 234 that receives the throttle pressure Pth, and a throttle pressure r't from the boat 234.
spool 236 that biases spool 232 toward boat 226 in response to
It has a spring 238 that biases it towards 6.

The area of the two lands from the bottom of the spool 232 is 01, R
2. If the area of the land of the spool 236 that receives the throttle pressure Pth is defined as F1a, and the acting force of the spring 238 is defined as W2, the following equation holds.

PA! 2=(port 3・Pth+W2−Bl・PT)/(port 2−Rl) (3) FIG. 9 shows the relationship between the second line pressure P12 generated by the sub-primary regulator valve 220 and its ideal value. It shows a relationship.

Shift valve 250 beam, input port 1-252 to which the second line pressure PJ2 is introduced during 14 range, output port 2
54,256, drain 26 through orifice 258
Boat 262 connected to 0, first line pressure PA' from boat 87 of manual valve 80 when in D range.
control boat 264 supplied with l, other control boats h
266,268, a drain 2701 spool 272, and a spring 274 that biases the spool 272 toward the boat 268. The control boat 266 , 268 is guided through an orifice 276 with a secondary hydraulic pressure Pz, and the hydraulic pressure of the control boat 266 , 268 is controlled by a solenoid valve 278 . The area of the two lands from the bottom of the spool 272 is St
, S2, and Sl<32. In addition, the solenoid valve 278
Turning on or off is controlled in relation to the driving parameters of the vehicle, and when it is on, oil is discharged from the drain 280.

When spool 272 is in the spring 274 position, input port 252 is connected to output port 254 and output port 256 is connected to drain 260 via boat 262 and orifice 258. Therefore output port 2
54 to the second line pressure PI! 2 is accumulator 28
2 and high speed clutch 56, and the auxiliary transmission 42 becomes high speed.

When spool 272 is in the boat 268 position, input boat 252 is connected to output port 256 and output port 254 is connected to drain 270.

Therefore, the second line pressure PA from output port 256
'2 is supplied to the low gear accumulator 58, and the auxiliary transmission 42 becomes the low gear.

In the case of the 14 range, the first line pressure PA'l is not introduced to the control port 264, so when the solenoid valve 278 is turned off, the spool 272 is initially moved by the secondary hydraulic pressure Pz acting on the land of area S2. , and then moves toward the spring 274 due to the secondary hydraulic pressure Pz acting on the land of area S1, but when the solenoid valve 278 is turned on, the control boat 266
．． As the oil pressure at 268 decreases, spool 272 is moved toward boat 268 by spring 274. i.e. 1
In the range, the auxiliary transmission 42 is switched between high speed and low speed depending on whether the solenoid valve 278 is turned on or off.

In the D range, the control boat 264 receives the first line pressure PA!
Since the + is guided, the spool 272 is connected to the -tan spring 274.
In the side position, the control boat 26 is placed on the land with area S2.
4, the spool 272 is in the position on the spring 274 side regardless of whether the solenoid valve 278 is turned on or off, and the auxiliary transmission 42 is placed in the high speed gear. is maintained.

The shift timing valve 290 is connected to the high speed clutch 5.
Control boat 292 and shift valve 25 communicating with 0
Human powered boat 29 connected to output boat 256 of 0
4. It has an output boat 296 connected to the low speed brake 58, a drain 298, a spool 300, and a spring 302 that biases the spool 300 toward the boat 292. When the shift valve 250 is switched from the low gear position to the high gear position, the second line pressure P/2 is supplied from the output boat 254 to the high gear clutch 56, but the hydraulic pressure of the high gear clutch 56 is still low. When it is low, the spool 300 is in a position on the boat 292 side due to the spring 302, and the oil of the low speed brake 58 is transferred to the shift valve 2.
50 boats 262 and orifice 258 from drain 260 . When the oil pressure of the high-speed clutch 56 increases, the spool 300 moves toward the boat 29.
2 moves against the spring 302, and the oil in the low gear rake 58 is quickly discharged from the drain 298 of the timing shift pulp 290. As a result, the shift in the auxiliary transmission 42 When uploading is performed,
The release of the low speed brake 58 is delayed appropriately, and the gear is shifted. #I attack is suppressed.

m1iI! The valves 100, 114, 116, 278 are guided by the secondary hydraulic pressure Pz from the secondary hydraulic oil passage 82, and the secondary hydraulic pressure Pz
control emissions. In the hydraulic control device disclosed in Japanese Patent Application No. 59-12017, the solenoid valve is guided by the throttle pressure Pth. Therefore, in conventional devices, the spring force and solenoid suction force of the solenoid valve must be set to cope with the maximum throttle pressure, which has the disadvantage of increasing the size of the solenoid valve. Deterioration of the spool response of the spool valve may occur,
There is a problem that the setting of the spring force acting on the spool is IPIM. In this embodiment, by using the secondary hydraulic pressure Pz, these delays are eliminated and the degree of freedom in design is improved.

FIG. 10 is a control block diagram. Electronic paper machine 310
receives parameters such as intake throttle opening 01, vehicle speed V, CVT l input side rotational speed Nin, engine cooling water temperature 11'TW%, and shift position as input signals, and operates the solenoid valve 100.114. of the hydraulic control system @312. 11
6,278 is controlled via an amplification stage 314.

The operation of the main parts of the embodiment will be explained with reference to FIG. 11.

In FIG. 11, Pch is the high speed clutch 56.
The servo hydraulic pressure is Pc7! is the low speed brake 58
It is a servo hydraulic.

Before time t1, the solenoid valve 278 for the shift pulp 250
is on, shift valve 250 is in the low gear position, and auxiliary transmission 42 is in the low gear position. Further, the solenoid valve 100 for the lock-up control valve 96 is on, and the secondary hydraulic pressure Pz is not guided to the control boat 194 of the cut-off valve +90, and the cut-off valve 190 is a primary regulator valve! 98 is permitted. Therefore, the first line pressure P7! l is the above (+)
The values are defined by the formula and the solid lines in FIGS. 7 and 8.

At time, the solenoid valve 278 is turned off, the shift valve 250 is in the high speed position, and the high speed clutch 56 is turned off.
The servo oil pressure Pch begins to rise. Since the timing shift valve 290 disconnects the bows 1 to 296 and the drain 298 until the servo oil pressure Pch reaches a predetermined value or more, the decrease in the servo oil pressure Pcl is delayed until time t3.

At time t2, the solenoid valve 1 for the lock-up control valve 96
00 is turned off. As a result, the cutoff valve 19
The secondary hydraulic pressure Pz is guided to the control boat 194 of 0, and the cutoff valve 190 is connected to the primary regulator pulp 19.
8. Therefore, the first
The line pressure P/1 becomes a value defined from equation (2) and the dashed-dotted lines in FIGS. 7 and 8, and increases. At the same time, the lock-up clutch 22 is also released, and the impact on the power transmission system is absorbed by the fluid clutch 12. While the auxiliary transmission 42 is shifting, an extra torque corresponding to the inertia torque is applied to the power transmission system on the input side of the auxiliary variable transmission 42, but due to the increase in the first line pressure pH from time t2, Slippage of the V-belt 6 of the CVT l is avoided.

Immediately before time t4, the low speed brake 58 is in a released state, and the high speed clutch 56 is in a fully engaged state.

At time t4, solenoid valve 1 of lock-up control valve 96
00 is turned on again and the oil in control boat 102 of lockup control valve 96 and control boat +94 of cutoff pulp 190 is drained through drain 104. As a result, the lock-up clutch 22 is released, and the clutch 1 to off-valve 190 allow transmission of the gear ratio pressure P to the primary regulator pulp 198, and the first line pressure P/l is calculated using the formula (1). and return to the values defined by the solid lines in FIGS. 7 and 8.

In this way, the first line pressure PI! l is the auxiliary transmission 42
During the shift period, the first line pressure PA' increases by 1, preventing the belt 6 from slipping during this period, improving the durability of the belt 6, and increasing the first line pressure PA' during the non-shift period of the auxiliary transmission 42. l is controlled to a normal low value to prevent deterioration of the durability of the belt 6 and deterioration of the fuel consumption rate due to an increase in the tension of the belt 6.

FIG. 12 shows another embodiment of the invention. A solenoid valve 320 that controls the introduction of the secondary hydraulic pressure Pz to the control boat 194 of the cut-off pulp +90 is provided separately from the 1!magnetic well 100 for the 1 pull-up control well 96.
22.324 prevents mutual interference of solenoid valve 100.3201
During the shifting period of the auxiliary transmission 42, the solenoid valve 320 is off, but during the non-shifting period, the solenoid valve 320 is turned on, and the oil in the control boat 194 is discharged from the drain 326.

Although the present invention has been described in terms of embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made within the spirit of the claims.

[Brief explanation of drawings]

Figure 1 is a stern diagram of the power transmission device with CVT, Figure 2 is a diagram showing the relationship between the range and the operating state of the frictional engagement device, and Figures 3 to 5 are detailed diagrams of the hydraulic control device. , Fig. 6 is a detailed diagram of the gear ratio detection valve, Figs. 7 and 8 are graphs showing the characteristics of the first line pressure, Fig. 9 is a graph showing the characteristics of the second line pressure, and 1O is a graph showing the characteristics of the second line pressure. A control block diagram, FIG. 11 is a diagram showing changes over time of each parameter during shifting of the auxiliary transmission, and FIG. 12 is a diagram showing another embodiment. 1...CVT, 42...Auxiliary transmission, 10
0.310 -- Solenoid valve, 190 -- Cut-off pulp, 198 -- Primary regulator valve, 31
0...Electronic control device. -1・-Ideal value of pH □ pH when the cut-off valve is open □ Gear ratio Gear ratio Figure 1 --- Ideal value of PI □ Gear ratio γ -°" - Ideal value of PI3 □ Gear ratio r Figure 11

Claims (1)

[Scope of Claims] 1. A hydraulic control device for a power transmission device with a continuously variable transmission, in which a continuously variable transmission and an auxiliary transmission having a plurality of forward gears are provided in series in a power transmission path of an engine, It is characterized by comprising a detection means for detecting a shift period of the auxiliary transmission, and a line pressure increasing means for increasing the line pressure of the continuously variable transmission during the shift period of the auxiliary transmission in response to the output of the detection means. A hydraulic control device for a power transmission device with a continuously variable transmission. 2. The line pressure increasing means includes a gear ratio detection valve that generates a gear ratio pressure as a decreasing function of the gear ratio of the continuously variable transmission, a line pressure generating valve that generates line pressure as a decreasing function of the gear ratio pressure, and a line pressure Claim 1, characterized in that it includes a cut-off valve that blocks the supply of gear ratio pressure to the generating valve, and a control means that sets the cut-off valve to a blocking position.
Hydraulic control device as described in section. 3. The hydraulic control device according to claim 2, wherein the control means is a solenoid valve that controls discharge of the control pressure of the cut-off valve. 4. The solenoid valve is a valve that controls engagement and release of a lock-up clutch that is provided in parallel to a fluid transmission device in a power transmission path of the engine and is held in a released state during a shift period of the auxiliary transmission. A hydraulic control device according to claim 3, characterized in that: 5. The hydraulic control device according to claim 4, wherein the auxiliary transmission is provided on the output side of the continuously variable transmission.