JPS61105350A - Shift controller for stepless transmission - Google Patents

Abstract

PURPOSE:To make a sudden drop in an engine speed preventable from occurring, by installing a flow limiting device which restricts a flow of oil to be fed to a driving pulley cylinder chamber, while letting hydraulic pressure in the driving pulley cylinder chamber go up slowly. CONSTITUTION:In case of up-shift speed, a spool 174 moves, enlarging a clearance interconnecting a port 172b and a port 172c, and simultaneously reducing another clearance interconnecting the port 172b and a port 172a. Therefore, hydraulic pressure in a driving pulley cylinder chamber slowly goes up. For this reason, when the hydraulic pressure in the driving pulley cylinder chamber goes up like this, a transmission gear ratio comes to be small but the hydraulic pressure in the driving pulley cylinder chamber gradually goes up so that speed change takes place slowly. And with this, an engine speed slowly comes to go down in consequence.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a speed change control device for a continuously variable transmission.

(B) Prior Art A conventional speed change control device for a continuously variable transmission is disclosed in, for example, Japanese Patent Application Laid-open No. 72758/1983. According to this, a flow rate restriction device is provided that restricts the flow of oil discharged from the driving pulley cylinder chamber and the driven pulley cylinder chamber. By installing a flow rate limiting device, it is possible to prevent a temporary drop in the oil pressure in the pulley cylinder chamber during a sudden downshift, thereby preventing belt slippage.

(c) Problems to be Solved by the Invention However, in such a conventional speed change control device for a continuously variable transmission, a flow rate restriction device was not provided in the oil path that supplies hydraulic pressure to the drive pulley cylinder chamber. There was a problem in that the gear change was performed rapidly during upshifting, resulting in an unfavorable driving feeling. In other words, when the shift control valve operates in the upshift direction, hydraulic pressure is suddenly supplied to the drive pulley cylinder chamber, causing a rapid upshift. ≠In an attempt to rapidly reduce the torque, a torque fluctuation occurs in the direction of accelerating the vehicle, so the driver feels something strange.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a shift control device for a continuously variable transmission that can perform upshifts with good feeling.

(d) Means for Solving the Problems The present invention achieves the above object by controlling the oil flowing into the drive pulley cylinder chamber with a flow rate restriction device. That is, the shift control device for a continuously variable transmission according to the present invention includes:
A flow restriction device is provided to restrict the flow of oil supplied to the drive pulley cylinder chamber. The flow restriction device is, for example, an orifice provided in an oil passage that supplies line pressure to the speed change control valve, or an orifice provided in the oil passage that supplies line pressure to the speed change control valve, or an outer circumference of a land whose outer diameter changes continuously in the axial direction of the spool of the speed change control valve and a valve hole. or a combination of the two. (e) Effect By having the above configuration, it becomes possible to control the oil flowing into the drive pulley cylinder chamber with a flow rate restriction device. , it is possible to reduce the speed change at the time of upshifting, reduce the rate of change in engine rotational speed, and obtain upshifting with a favorable driving feeling.

(F) Embodiment FIG. 2 shows a power transmission mechanism of a continuously variable transmission. engine 1
A fluid coupling 12, which is a fluid transmission device, is connected to the output shaft 10a. The fluid coupling 12 is equipped with a lock-up mechanism, and can mechanically connect or disconnect the pump impeller 12b on the input side and the turbine runner 12C on the output side by controlling the oil pressure in the lock-up oil chamber 12a. be.

The output side of the fluid coupling 12 is connected to the rotating shaft 13. The rotating shaft 13 is connected to a forward/reverse switching mechanism 15 . The forward/rear forward switching mechanism 15 is a planetary gear mechanism 17.
．． It has a forward clutch 40 and a reverse brake 50. The planetary gear mechanism 17 includes a sun gear 19 and a pinion carrier 2 having two pinion gears 21 and 23.
5 and an internal gear 27. The two pinion gears 21 and 23 are engaged with each other,
Pinion gear 21 meshes with sun gear 19, and pinion gear 23 meshes with internal gear 27. Sun gear 19 is always connected to rotary shaft 13 so as to rotate together with it. The pinion carrier 725 can be connected to the rotating shaft 13 by the forward clutch 40. Moreover, the internal gear 27 can be fixed to the stationary part by the reverse brake 5o. The pinion carrier 25 is connected to a drive shaft 14 disposed around the outer periphery of the rotating shaft 13. A drive pulley 16 is provided on the drive shaft 14 . The drive pulley 16 includes a fixed conical plate 18 that rotates together with the drive shaft 14, and a V-shaped pulley groove formed by opposing the fixed conical plate 18. The movable conical plate 22 is movable in 14 axial directions. The drive pulley cylinder chamber 2o is composed of two chambers 2a and 20b, and has a pressure receiving area twice that of a driven pulley cylinder chamber 32, which will be described later. , the driving pulley 16 is coupled to a driven pulley 26 by a V-belt 24 in a transmission manner. The driven pulley 26 is provided on the driven @28. The driven pulley 26 includes a fixed conical plate 30 that rotates together with the driven shaft 28, and a V-shaped boob groove formed by opposing the fixed conical plate 30. 2
8, a movable conical plate 34 is movable in the axial direction. These drive pulley 16, belt 24, and driven pulley 26 create belt type continuously variable transmission mechanism 29.
is configured.

A drive gear 46 is fixed to the driven shaft 28, and this drive gear 46 meshes with an idler gear 48 on an idler shaft 52. A pinion gear 54 provided on the idler shaft 52 is always engaged with the final gear 44. A pair of pinion gears 58 and 60 constituting a differential device 56 are attached to the final gear 44, and a pair of side gears 62 and 64 are engaged with the pinion gears 58 and 60, respectively. It is connected to output shafts 66 and 68.

The output shaft 10 of the engine 10 is attached to the power transmission mechanism as described above.
The rotational force input from a is transmitted to the fluid coupling 12
and is transmitted to the forward/reverse switching mechanism 15 via the rotating shaft 13, and via the planetary gear mechanism 17, which is in an integrally rotating state when the forward clutch 40 is engaged and the reverse brake 50 is released. The rotational force of the rotating shaft 13 is transmitted to the drive shaft 14 in the same rotational direction, and when the forward clutch 40 is released and the reverse brake 50 is engaged, the rotational force of the rotating shaft 13 is transmitted to the drive shaft 14 in the same rotational direction. The rotational force of the rotary shaft 13 is transmitted to the drive shaft 14 with the rotation direction reversed. The rotational force of the drive shaft 14 is applied to the drive pulley 1
6, ■ Differential device 5 via belt 24, driven pulley 26, drive shaft 28, drive gear 46, idler gear 48, idler shaft 52, pinion gear 54 and final gear 44
6, and the output shafts 66 and 68 rotate in the forward or reverse direction. Note that when both the forward clutch 40 and the reverse brake 50 are released, the power transmission mechanism is in a neutral state. When transmitting power as described above,
Movable conical plate 22 of drive pulley 16 and driven pulley 26
■Belt 24 by moving the movable conical plate 34 in the axial direction.
By changing the radius of contact with the drive pulley 16
For example, if the width of the V-shaped pulley groove of the drive pulley 16 is expanded and the width of the V-shaped pulley groove of the driven pulley 26 is reduced, the rotation ratio of the drive pulley 16 can be changed. The contact radius of the V-belt on the side becomes smaller, and the contact radius of the V-belt on the driven pulley 26 side becomes larger, resulting in a large gear ratio. If the movable conical plates 22 and 34 are moved in the opposite direction, the gear ratio will become smaller, completely opposite to the above.

Next, a hydraulic control device for this continuously variable transmission will be explained. As shown in Fig. 1, the hydraulic control device includes an oil pump 1.
01, line pressure adjustment valve 102, manual valve 104, speed change control valve 106, adjustment pressure switching valve 108, speed change motor 110
, speed change operation mechanism 112, throttle valve 114, constant pressure regulating valve 116, solenoid valve 118, coupling correct adjustment/pressure valve 1
20, a lock-up control valve 122, etc.

The oil pump 101 sucks oil in the tank 130 through the strainer 31 and discharges it into the oil path 132. The oil discharged from the oil passage 132 is discharged from the line pressure regulating valve 102 (bow) 14
6b, 146d, and 146e, and the line pressure is regulated to a predetermined pressure as described later. The oil passage 132 is
Boat 192c of throttle valve 114 and speed change control valve 1
It also communicates with boat 172c of No. 06. Also, oil path 1
32 also communicates with the boat 204b of the constant pressure regulating valve 116. Note that a line pressure relief valve 13 is installed in the oil passage 132.
3 is provided to prevent the line pressure from becoming abnormally high.

The manual valve 104 has one port) 134a, 134b.
, 134c, 134d and 134e.
and a spool 136 having two lands 136a and 136b corresponding to the valve hole 134.

The spool 136, which is operated by a select lever (not shown) on the driver's seat, has a stop position of P, R, N, D, and Lf. Boats 134a and 134e are drain boats, and boat 134b communicates with forward clutch 40 through oil passage 142.

Note that the oil passage 142 is provided with a one-way orifice 14 that has a throttling effect only when supplying hydraulic pressure to the forward clutch 40.
3 is provided. Also, the boat 134c is connected to the oil passage 140.
Boats 192b and 19 of throttle valve 114 by
2d, and the bow) 134d communicates with the reverse brake 50 through an oil passage 138. Note that the oil passage 138 is provided with a one-way orifice 139 that has a throttling effect only when supplying hydraulic pressure to the reverse brake 50. When the spool 136 is in the P position, the throttle valve 1
The boat 134c is closed by the land 136a, and the forward clutch 40 is drained from the drain port 134a of the valve hole 134 through the oil passage 142. ,
Further, the reverse brake 50 is drained from the drain port 134e via the oil passage 138. Spool 13
6 is in the R position, the boat 134c and the boat 134d
communicates between lands 136a and 136b,
The throttle pressure of the oil passage 140 is supplied to the reverse brake 50, while the forward clutch 40 is drained via the boat 134a. When the spool 136 comes to the N position,
Boat 134C is sandwiched between lands 136a and 136b and cannot communicate with other boats;
Since both boats 134b and 134d are drained, the reverse brake 50 and the forward clutch 40 are both drained as in the P position. When the spool 136 is in the D=homo or L-F position, the boat 134b
and the boat 134c communicate with each other at a distance of Ω1 between the lands 136a and 136b, and pressure is supplied to the forward clutch 40, while the reverse brake 50 is drained via the boat 134e. As a result, the spool 13
6 is in the P or N position, the forward clutch 40
and the reverse brake 50 are both released and power transmission is cut off, the rotational force of the rotary shaft 13 is not transmitted to the drive shaft 14, and when the spool 136 is in the R position, the reverse brake 50 is released.
is fastened, the output shafts 66 and 68 are driven in the reverse direction as described above, and the spool 136 is
), the forward clutch 40 is engaged and the output shafts 66 and 68 are driven in the forward direction. Note that the D position = Mihogumo Seiko and L; as mentioned above, there is no difference between the positions in terms of the hydraulic circuit, but both positions are detected electrically and are shifted according to different shift patterns. The operation of the variable speed motor 110, which will be described later, is controlled in this manner.

The line pressure regulating valve 102 has seven boats 146a-14.
6b, 146c, 146d, 146e, 146f and 1
A valve hole 146 having a diameter of 46g and five lands 148a, 148b, 148c, 148 corresponding to this valve hole 146.
Spool 148 with d and 148e
- It consists of an axially movable sleeve 150 and two springs 152 and 154 arranged concentrically between the spool 148 and the sleeve 150. The sleeve 150 is adapted to receive a pressing force in the left direction in FIG. 1 from the pressing member 158. Pressing member 158
is supported movably in the axial direction with respect to the valve body, and the other end is connected to the movable conical plate 22 of the drive pulley 16.
It engages with a groove 22a provided on the outer periphery of. Therefore,
As the gear ratio increases, the sleeve 150 moves to the left in the figure, and as the gear ratio decreases, the sleeve 150 moves to the right in the figure. Of the two springs 152 and 154,
The spring 152 on the outer circumferential side is always in a compressed state with both ends in contact with the sleeve 150 and the spool 148, respectively, but the spring 154 on the inner circumferential side is compressed only when the sleeve 150 moves to the left in the figure by a predetermined amount. It's Nishide. The boat 146a of the line pressure regulating valve 102 is a drain port. Boat 146. Throttle pressure is supplied to g from an oil passage 140 which is a throttle pressure circuit. The boat 146c is connected to an oil line 164 which is a drain circuit.
is connected to. Boats 146b, 146d and 146
e communicates with an oil passage 132 which is a line pressure circuit. The boat 146f communicates with the boat 230b of the coupling pressure regulating valve 120 via an oil passage 165. In addition, oil path 1
65 communicates with the line pressure oil passage 132 via an orifice 199. Note that orifices 166 and 170 are provided at the inlets of boats 146b and 146g, respectively. In the end, the spool 148 of this line pressure regulating valve 102
The force due to spring 152 (or spring 15
2 and 154) and the force exerted by the oil pressure (throttle pressure) of boat 146g on the area difference between lands 148d and 148e;
A force in the right direction due to the hydraulic pressure (line pressure) of the boat 146b acts on the difference in area between the spool 148 and the boat 148b.
Amount of oil leaked to 6c and from boat 146e to boat 14
The line pressure of the bow h146b is controlled so that the forces in the left and right directions are always balanced by adjusting the amount of oil leaking to 6f. Therefore, the line pressure increases as the gear ratio increases, and the line pressure increases as the throttle pressure acting on the boat 146g increases. To adjust the line pressure in this way, the larger the gear ratio, the greater the pulley's pushing force against the V belt.
This is because when the throttle pressure is high (that is, when the negative pressure in the engine intake pipe is low), the engine output torque is high, so the oil pressure is increased to increase the V-belt pressing force of the pulley, thereby increasing the power transmission torque due to friction.

The speed change control valve 106 has five bows) 172a, 172b.
, 172C, 1172d and 172e.
and three lands 174a corresponding to this valve hole 172,
It consists of a spool 174 having angles of 17° 4b and 174c, and a spring 175 that pushes the spool 174 to the left in the figure.

R-toimo≠l 72b communicates with the drive pulley cylinder chamber 20 via an oil passage 176, and the boat 172a and the boat 172e are drain ports. In addition, Bo)
An orifice 177 is provided at the outlet of 172a. The boat 172d communicates with the driven pulley cylinder chamber 32 via an oil passage 179. The boat 172C communicates with the oil passage 132, which is a line pressure circuit, and is supplied with line pressure. The left end of the spool 174 is rotatably connected to a substantially central portion of a lever 178 of a shift operation mechanism 112, which will be described later, by a pin 181. Since the land 174b has a curved axial cross section, the line pressure supplied to the boat 172c flows into the bow h 172b, but a portion of it is discharged to the boat 172a, so the pressure in the boat 172b is equal to the inflowing oil. The pressure is determined by the rate of oil being discharged. Therefore, as the spool 174 moves to the left, the line pressure side clearance of the boat 172b increases and the discharge side clearance decreases, so the pressure of the boat 172b gradually increases.On the other hand, the boat 172d normally has a line pressure is supplied.

The oil pressure of the boat 172b is supplied to the driving pulley cylinder chamber 20 via an oil passage 176, and the oil pressure of the boat 172d is supplied to the driven pulley cylinder chamber 32 via an oil passage 179. Therefore, when the spool 174 moves to the left, the pressure in the drive pulley cylinder chamber 20 increases and the width of the V-shaped pulley groove of the drive pulley 16 becomes smaller, while the width of the V-shaped pulley groove of the driven pulley 26 decreases. becomes larger. That is, the V-belt contact radius of the drive pulley 16 becomes larger and the V-belt contact radius of the driven pulley 26 becomes smaller, so that the gear ratio becomes smaller. On the contrary, spool 174
If you move it to the right, the effect is completely opposite to the above, and
The gear ratio becomes larger.

As described above, the lever 178 of the speed change operation mechanism 112 is connected to the spool 174 of the speed change control valve 106 at approximately the center thereof.
is connected to the lever 178 by a pin 181.
One end is connected to the aforementioned pressing member 158 by a pin 183, and the other end is connected to a rod 182 by a pin 185. Rod 182 is rack 182C
This rack 182C has a variable speed motor 110.
By rotating the pinion gear 110a of the variable speed motor 110 controlled by the control device, the rod 1
For example, when the lever 82 is moved to the right in the figure, the lever 178
rotates clockwise around pin 183, and lever 1
78 is moved to the right. As a result, as described above, the movable conical plate 22 of the driving pulley 16 moves to the left in FIG. The interval between the V-shaped boolean grooves of the pulley 26 becomes smaller, and the gear ratio becomes larger. One end of the lever 178 is connected to the pressing member 158 by a pin 183, so when the pressing member 158 moves to the left in FIG. 1 as the movable conical plate 22 moves, the other end of the lever 178 The lever 178 rotates clockwise using the side pin 185 as a fulcrum. For this reason, spool 17
4 is pulled back to the left to bring the driving pulley 16 and the driven pulley 26 into a state where the gear ratio is small. Through such operations, the spool 174, drive pulley 16, and driven pulley 26 are stabilized at a predetermined speed ratio corresponding to the rotational position of the speed change motor 110. variable speed motor 11
The same is true when rotating 0 in the opposite direction (note that the rod 182 can move further to the right in the figure (overstroke area) beyond the position corresponding to the maximum gear ratio; Then, the changeover detection switch 29
8 is activated, and this signal is input to the speed change control device ENCHUGIN]. Therefore, when the speed change motor 110 is operated according to a predetermined speed change pattern, the speed ratio changes accordingly, and the speed change occurs. By controlling the motor 110, the speed change of the continuously variable transmission mechanism can be controlled.

Variable speed motor (referred to as "step motor" in the following explanation)
110, the rotational position is determined in response to a pulse number signal sent from the transmission control device. The pulse number signal from the speed change control device is given according to a predetermined speed change pattern.

The regulating pressure switching valve 108 has its valve body connected to the speed change operation mechanism 112.
It is formed integrally with the rod 182 of.

That is, the regulating pressure switching valve 108 has ports 186a and 18
It consists of a valve hole 186 having holes 6b, 186C and 186d, and lands 182a and 182b formed on the rod 182. Port 186a communicates with oil passage 188. The port 186b is connected to the solenoid valve 1 via the oil passage 190.
It communicates with 18. Port 186c communicates with oil passage 189. Port 186d is a drain port.

Normally port 186a and baud 1486b are land 18
2a and 182b, but the rod 1
Port 186a is closed, and port 186b and port 186C are brought into communication only when gear ratio 82 moves beyond the position corresponding to the maximum speed ratio value to an overstroke region.

The throttle valve 114 has ports 192a, 192b, 1
A valve hole 192 having 92C1192d, 192e, 192f and 192g and five lands 194a, 194b, 194c, 194d and 194 corresponding to the valve hole 192.
It is made up of a spool 194 having a diameter of 1.e, and a negative pressure diaphragm 198 that applies a pushing force to the spool 194. The negative pressure diaphragm 198 applies a force inversely proportional to the negative pressure to the spool 194 when the negative pressure in the engine intake pipe is lower than a predetermined value (for example, 300 mmHg) (close to atmospheric pressure). If the value is higher than a predetermined value, no force is applied at all. Port 192a is a drain boat, ports 192b and 192d are in communication with an oil passage 140 which is a throttle pressure circuit, port 192c is in communication with an oil passage 132 which is a line pressure circuit, and ports 192e and 192f are in communication with a drain boat. & t, and the boat 192 zero is in communication with the oil passage 189 mentioned above. Orifices 202 and 203 are provided at the inlets of ports 192b and 192e, respectively. The hydraulic pressure of the boat 192-e is connected to the land 194d and the land 194e on the spool 194.
The force acting on the area difference between the negative pressure diaphragm 19
8, and a force directed to the right in the figure, the force due to the oil pressure of the port 192b acting on the area difference between the lands 194a and 194b. However, the throttle valve 114 balances the forces in both directions. like bo)
Using the line pressure of 192c as a pressure source and using port 192e as a discharge boat, a well-known pressure regulating action is performed. As a result, throttle pressure corresponding to the force of the hydraulic pressure of port 192o and the force of negative pressure diaphragm 198 is applied to ports 192b and 192d. Occur. The throttle pressure obtained in this manner is regulated in accordance with the engine intake pipe negative pressure, and therefore corresponds to the engine output torque. That is, if the carrot output torque is large, the throttle pressure also becomes a correspondingly high oil pressure. Note that the throttle pressure is also adjusted by the hydraulic pressure (adjustment pressure) of the bow h192g as described later.

The constant pressure regulating valve 116 has ports 204a, 204b, 2
a valve hole 204 having 04c, 204d and 204e;
A spool 206 having lands 206a and 206b, and a spring 208 that pushes the spool 206 to the left in the figure.
It consists of.

Ports 204a and 204C communicate with oil passage 209. Port 204b communicates with oil passage 132, which is a line pressure circuit. 204d and 204e are drain ports. Orifice 2 is located at the entrance of port 204a.
16 is the provision. The constant pressure regulating valve 116 has a function of regulating a constant hydraulic pressure corresponding to the force of the spring 208 by a well-known pressure regulating function, and supplying this to the oil passage 209. Note that the oil passage 209 and the aforementioned oil passages 188 and 189 are connected via choke-type throttle valves 250 and 252, respectively. In addition, a filter 2 is provided in the oil passage 209.
11 are provided.

The electromagnetic valve 118 has an adjustable tee ratio controlled by a plunger 224a biased in the closing direction by a spring 225 to control the amount of oil discharged from the oil passage 190 to the port 222, and the amount of oil discharged from the oil passage 190 to the port 222 is controlled by a plunger 224a in proportion to the amount of energization. In order to discharge oil, the oil pressure (adjustment pressure) of the oil passage 190 is controlled in inverse proportion to the amount of energization. In an idling state where the vehicle is stopped, the rod 182 moves to the overstroke region, the regulating pressure switching valve 108 is in the state shown in the lower half of FIG. 1, and the oil passage 190 communicates with the oil passage 189. The regulated pressure obtained by the solenoid valve 118 is applied to the port 19 of the throttle valve 114.
Acts on 2g. As a result, the throttle pressure is controlled so that the forward clutch 16 or the reverse clutch 26 is slightly engaged. Before starting, this throttle pressure is always applied to the forward clutch 16 or reverse clutch 2.
6, the specified creep torque can be obtained, and the shift at the time of N4D, N→R selection, etc. is also reduced.As soon as 0 start is started, the throttle pressure increases and the forward pressure is increased. Clutch 16 or reverse clutch 2
6 is fully tightened. On the other hand, during normal driving, the regulating pressure switching valve 108 is in the state shown in the upper half, and the oil passage 19 is in the state shown in the upper half.
0 and the oil passage 188, switching of the lock-up control pulp 122 can be controlled by adjusting pressure as described later.

The coupling pressure regulating valve 120 has ports 230a, 23
It consists of a valve hole 230 having holes 0b, 230C1230d, and 230e, a spool 232 having lands 232a and 232b, and a spring 234 that pushes the spool 232 to the left in the figure. Bo) 230a and 23
0C communicates with the oil passage 235, and the port 230b is supplied with drained oil from the line pressure regulating valve 102 from the oil passage 165, and the ports 230d and 230e are drain boats. An orifice 236 is provided at the entrance of the port 230a. This coupling pressure regulating valve 120 uses the hydraulic pressure supplied to the bow 230b from the oil passage 165 as a hydraulic pressure source to regulate a constant hydraulic pressure (coupling pressure) corresponding to the force of the spring 234, and supplies this to the oil passage 235. It has the function of supplying This coupling pressure is used as the operating pressure of the fluid coupling 12 and is also used to control the operation of the lock-up mechanism.

The lock-up control valve 122 is connected to the boats 240a, 24
0 b, 240 c, 240 d, 240 e
, 240f, 240g and 240h.
and a spool 242 having lands 242a, 242b, 242C1242d, and 242e. The boat 240a and the boat 240g are drain boats, and the boat 240b communicates with the oil passage 209.
The boats 240c and 240f communicate with the lock-up oil chamber 12a via an oil passage 243, and the boat 240d is connected with an oil passage 245 that communicates with the fluid coupling 12. A constant coupling pressure is supplied to the bow 240e from an oil passage 235. The boat 240h is connected to the oil passage 188 described above. Boat 240b, 2
The inlets of 40C 1240g and 240h are provided with orifices 246, 247, 248 and 249, respectively. This lock-up control valve 122 has a function of controlling the supply of hydraulic pressure to the fluid coupling 12 and the lock-up oil chamber 12a. The spool 242 is operated by the force due to the hydraulic pressure of the bow h240b (this hydraulic pressure is a constant pressure regulated by the constant pressure pressure regulating valve 116) acting on the area difference between the land 242a and the land 242b, and the force between the land 242b and the land 242C. The force due to the hydraulic pressure of the boat 240C acting on the area difference between the land 242e and the land 242e
It is switched depending on the balance with the oil pressure (adjustment pressure) of the boat 240h acting on the end of the boat 240h. When the spool 242 is in the position shown in the upper half of FIG.
The coupling pressure of the oil passage 235 communicated through M and regulated by the coupling pressure regulating valve 120 is supplied to the fluid coupling 12 . Note that a relief valve 250 is provided in the oil passage 245 to prevent abnormally high oil pressure from acting on the fluid coupling 12. Further, when the spool 242 is in the upper half position, the boats 240f and 240g communicate between the lands 242d and 242e, and the pressure in the lock-up oil chamber 12a is
Drained from 40g. Therefore, the lock-up mechanism is tightened and enters the lock-up state. Conversely, when the spool 242 is at the position shown in the lower half of Figure 1, the boats 240e and 240f communicate between the lands 242d and 242e, and the coupling pressure of the oil passage 235 is locked up through the oil passage 243. The oil is supplied to the oil chamber 12a. On the other hand, the boat 240d has land 242C and land 2.
42d. Therefore, the lock-up mechanism is in a released state, and the fluid coupling 12 is supplied with operating pressure from the lock-up oil chamber 12a side. The oil pressure of the fluid coupling 12 is transmitted through the oil passage 245.
The pressure is maintained at a constant pressure by a pressure-holding valve 252 provided at. The oil discharged through the pressure holding valve 252 is sent to the cooler 256 through the oil passage 254, where it is cooled and then used for lubrication. Note that the oil passage 254 is equipped with a cooler pressure holding valve 25.
8 is provided, and the oil discharged from the cooler pressure holding valve 258 is returned to the suction port of the oil pump 101 through the oil passage 164. The oil passage 254 is led to the sliding portion between the pressing member 158 and the help body, and is designed to lubricate this. In addition, the oil passage 254 has an orifice 259
The oil passage 235 is connected to the oil passage 235 so that the minimum required amount of oil is always supplied.

Next, the speed change control valve 106 provided with the flow restriction device according to the present invention will be further explained with reference to FIG. The flow restriction device is connected to land 1 of the spool 174 of the speed change control valve 106.
It is constituted by a gap between 74b and the valve hole 172. The land 174b has a shape whose outer diameter changes continuously in the axial direction. In a steady state, the boat 1 is passed through this gap from the boat 172C side where line pressure is applied.
Oil flows into the boat L72b, and part of it is discharged to the boat L72a, and the oil pressure of the boat 172b is set to a predetermined value depending on the balance between the inflowing oil and the discharged oil. The oil pressure of this boat 172b acts on the drive pulley cylinder chamber 20 via the oil passage 176. In the case of an upshift, the transmission is transmitted to the stay and bumo pool 174, and the spool l'/4 moves to the left in the figure, and is transferred to the port 17.
Expand the gap that connects 2b and port C 172S, and at the same time
The gap between the port 172b and the port 172a is reduced. For this reason, the oil pressure in the port 172b increases, but the oil pressure is supplied while being limited by the small gap between the valve hole 172 and the outer periphery of the land 174b.
The oil pressure in the drive pulley cylinder chamber 20 gradually increases.

When the oil pressure in the drive pulley cylinder chamber 20 increases, the gear ratio decreases as described above, but the drive pulley cylinder chamber 2
Since the oil pressure at 0 gradually increases, the gear shift is performed slowly. Along with this, the engine rotational speed also gradually decreases, and smooth gear shifting and changes in the engine rotational speed are performed. This makes it possible to obtain a favorable driving feeling.

Note that since the outer diameter of the land 174b changes in the axial direction in a substantially tapered manner, when the spool 174 undergoes a relatively small displacement, the clearance becomes small; When the displacement is relatively large, the gap becomes thicker. By doing this, when gradual acceleration is being performed, the speed change of the upshift speed change can be slowed down and the speed of change in engine rotation can be reduced, while the speed change motor 110 is commanded to perform a rapid upshift speed change. (For example, when the throttle is suddenly returned while driving at a large throttle opening), hydraulic pressure is relatively rapidly supplied to the drive pulley cylinder chamber 20 to perform a quick upshift and prevent excessive engine pressure. It is possible to prevent the occurrence of brakes, shocks, etc.

In this embodiment, the flow restriction device is configured by the gap between the valve hole 172 and the outer periphery of the land 174b as described above, but a third As shown in the figure, it can be constructed by providing an orifice 132a, or as shown in Figure 3, this orifice and the above-mentioned gap can be combined to form a flow rate restricting device.If both are used together, the land The substantially tapered portion of 174b is made into a larger taper shape so as not to trap foreign matter in the hydraulic oil,
The orifice 132a can compensate for the decrease in the flow rate restriction effect of this tapered portion. In addition to this, the flow rate restricting device may also include a portion with a diameter slightly smaller than the outer diameter of the land of the spool, a notch formed on the outer circumference of the land of the spool,
It is also possible to form a small hole or the like that passes through the land of the spool in the axial direction.

(g) As described in detail, according to the present invention, a flow rate restriction device is provided that restricts the flow of oil supplied to the drive pulley cylinder chamber, so that the oil pressure in the drive pulley cylinder chamber is gradually reduced. This allows the upshift to be performed slowly. This prevents a sudden drop in engine speed and improves driving feeling. In addition, by forming the flow restriction device using a run whose outer diameter tapers in the axial direction, the effect of the flow restriction device can be made variable according to the shifting conditions, resulting in a more favorable driving feel. You can also choose to get a ring.

[Brief explanation of the drawing]

Figure 1 shows the entire hydraulic control system of the continuously variable transmission, Figure 2 shows the entire hydraulic control system of the continuously variable transmission.
The figure shows the power transmission mechanism of the continuously variable transmission, and FIG. 3 is an enlarged view of the speed change control valve. 16・Rumors・Drive pulley, 20ψ・Φ Drive pulley cylinder chamber, 26... Driven pulley, 32... Driven pulley cylinder chamber, 106... Speed change control valve, 132a*... Orifice, 172... Valve Hole, 174...ψ stool, 1
74b--Land.

Claims (1)

[Scope of Claims] 1. A speed change control device for a continuously variable transmission equipped with a driving pulley and a driven pulley, the groove intervals of which are variable depending on the hydraulic pressure of the driving pulley cylinder chamber and the driven pulley cylinder chamber, respectively. In a speed change control device having a speed change control valve that controls the transmission ratio by controlling the supply and discharge of hydraulic pressure to both the driven pulley cylinder chamber and the driven pulley cylinder chamber, the flow of oil supplied to the driving pulley cylinder chamber is controlled. A speed change control device for a continuously variable transmission, characterized in that a flow rate restriction device is provided. 2. The continuously variable transmission according to claim 1, wherein the flow rate limiting device is constituted by a gap between the valve hole and the outer circumference of a land whose outer diameter changes continuously in the axial direction of the spool of the speed change control valve. Machine speed control device. 3. The flow restriction device is an orifice provided in an oil passage that supplies line pressure to the speed change control valve.
A speed change control device for a continuously variable transmission as described in 2. 4. The flow rate restriction device consists of an orifice provided in the oil passage that supplies line pressure to the speed change control valve, an outer periphery of a land whose outer diameter changes continuously in the axial direction of the speed change control valve spool, and a valve hole. 2. The speed change control device for a continuously variable transmission according to claim 1, which is a combination of the following.