JPH0375773B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control system for a hydraulic automatic clutch.

When a hydraulic automatic clutch is applied to a vehicle, it is necessary to smoothly engage the clutch when the vehicle starts, and for this reason, it is conceivable to use hydraulic pressure that increases in accordance with engine rotational speed as the clutch operating pressure. This provides an effect almost similar to that of a centrifugal clutch. However, in the automatic clutch that performs start control as described above, the clutch operating pressure is oil pressure that corresponds to the engine rotation speed, so in the region below a predetermined engine rotation speed, the clutch is released or becomes a half-clutch state regardless of the gear ratio. There was a problem that normal driving was not possible. In order to solve the above-mentioned problems, the present applicant has filed Japanese Patent Application No. 57-184628 entitled "Control Device for Hydraulic Automatic Clutch" (filed on October 22, 1988) (Japanese Patent Application No. 59-75841). When the vehicle speed is below a predetermined fully engaged vehicle speed, a starting hydraulic pressure that increases in accordance with the engine rotation speed is supplied to the clutch, and when the vehicle speed is above the fully engaged vehicle speed, the starting hydraulic pressure is higher than the starting hydraulic pressure. A control device for a hydraulic automatic clutch that supplies complete engagement hydraulic pressure is disclosed. but,
In the above-mentioned control system, the clutch is always fully engaged when the vehicle speed exceeds a predetermined fully engaged vehicle speed, which may cause the following problem under heavy load running conditions. In other words, when driving under heavy load conditions such as when climbing a slope, if the vehicle speed increases from a state where the clutch is partially engaged at a speed lower than the fully engaged vehicle speed and exceeds the fully engaged vehicle speed, the clutch is immediately disengaged. Complete fastening will occur, but in this case a very large fastening shock will occur. Furthermore, as the clutch is engaged, the engine rotational speed rapidly decreases, resulting in a decrease in driving force.

The present invention has been made by focusing on the above-mentioned problem, and when the vehicle speed is equal to or higher than a predetermined fully engaged vehicle speed and the difference between the input rotational speed and the output rotational speed of the clutch is less than or equal to a predetermined value (i.e., It is an object of the present invention to solve the above-mentioned problems by fully engaging the clutch only when the slippage of the clutch is small.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 1 to 14 of the accompanying drawings showing embodiments thereof.

FIG. 1 shows a power transmission mechanism of a continuously variable transmission to which the present invention is applied. An input shaft 2, which is connected to the crankshaft of the engine, can be connected via a forward clutch 4 to a drive shaft 8 with a drive pulley 6. The input shaft 2 is provided with an external gear type oil pump 10 that is a hydraulic pressure source for a hydraulic control device to be described later. The oil pump 10 has a driving gear 12 and a driven gear 14. A rotary groove 16 is attached to the input shaft 2 so as to be integrally rotatable.The rotary groove 16 forms an oil pool 18 by bending the outer periphery of a substantially disc-shaped plate inward. It is designed to hold oil that rotates together with the rotating groove 16. In addition, oil pool 1
Preferably, the grooves 8 are provided with irregularities that act as vanes to improve the ability of the oil to follow changes in rotation of the rotary groove 16. Further, the rotating gutter 16 is provided with a conduit (not shown) that always supplies a predetermined amount of oil into the oil reservoir 18. Rotating groove 16
A pitot tube 20 having an opening facing the flow of oil that rotates together with the rotary groove 16 faces into the oil reservoir 18 , and the dynamic pressure of the oil in the oil reservoir 18 is controlled by the pitot tube 20 . Detectable. A subshaft 22 is rotatably provided parallel to the input shaft 2, and a reverse clutch 24 is provided at one end of the subshaft 22. The input shaft 2 and sub-shaft 22 are each
It has gears 26 and 28 that mesh with each other.
The gear 26 can always rotate integrally with the input shaft 2,
Further, the gear 28 can rotate integrally with the countershaft 22 via the reverse clutch 24. A gear 34 is integrally provided on the other end side of the subshaft 22, and the gear 34 meshes with the gear 32 that is rotatably supported.
The gear 32 is a gear 30 that can rotate integrally with the drive shaft 8.
They are interlocked. The forward clutch 4 and the reverse clutch 24 are both engaged when hydraulic pressure is introduced into their piston chambers 36 and 38 from a hydraulic control device, which will be described later. When the forward clutch 4 is engaged, the engine rotation transmitted from the input shaft 2 is transmitted to the drive shaft 8 with normal rotation, while when the reverse clutch 24 is engaged, the engine rotation is transmitted through the gears 26, 28, 34. ,3
2 and 30, the rotation is reversed and transmitted to the drive shaft 8. The drive pulley 6 includes a fixed conical plate 40 formed integrally with the drive shaft 8 and a fixed conical plate 40.
The movable conical plate 44 is arranged opposite to the movable conical plate 44 to form a V-shaped pulley groove, and is movable in the axial direction of the drive shaft 8 by the hydraulic pressure acting on the drive pulley cylinder chamber 42. The maximum width of the V-shaped pulley groove is regulated by a stopper (not shown) that acts when the movable conical plate 44 moves a predetermined amount to the left in the figure. The fixed conical plate 40 of the driving pulley 6 is also provided with a rotating groove 46 that is substantially similar to the rotating groove 16 described above. The dynamic pressure of the oil in the oil reservoir 47 of the rotating gutter 46 is controlled by the pitot tube 48.
A predetermined amount of oil is always supplied into the oil reservoir 47 by an oil pipe (not shown). The driving pulley 6 is connected to a driven pulley 51 through a V-belt 50 so as to be able to transmit transmission, and this driven pulley 51 is connected to a rotatable driven shaft 5.
It is located on 2. The driven pulley 51 includes a fixed conical plate 54 formed integrally with the driven shaft 52;
It is arranged opposite to the fixed conical plate 54 to form a V-shaped pulley groove and a driven pulley cylinder chamber 56.
A movable conical plate 5 that is movable in the axial direction of the driven shaft 52 by the hydraulic pressure and spring 57 acting on the
It consists of 8. As with the drive pulley 6, the axial movement of the movable conical plate 58 is limited by a stopper (not shown) so that it does not exceed the maximum V-shaped pulley groove width. The pressure receiving area of the driven pulley cylinder chamber 56 is approximately 1/2 of the pressure receiving area of the driving pulley cylinder chamber 42. A gear 60 provided to rotate integrally with the driven shaft 52 is meshed with a ring gear 62. That is, the rotational force of the driven shaft 52 is
is transmitted to the ring gear 62 via. The differential case 64 to which the ring gear 62 is attached has 1
A pair of pinion gears 66 and 68 and a pair of side gears 72 and 74 that mesh with the pinion gears 66 and 68 to form a differential 70 are provided. Output shafts 76 and 78 are connected to the side gears 72 and 74, respectively.

The rotational force input from the engine crankshaft to the power transmission mechanism of the continuously variable transmission as described above is transferred from the input shaft 2 to the drive shaft 8 via the forward clutch 4 (or from the input shaft 2 to the gear 26, gear 2
8, reverse clutch 24, subshaft 22, gear 34,
The signal is transmitted to the drive shaft 8 via the gears 32 and 30, and is then transmitted to the drive pulley 6, V-belt 50, driven pulley 51, and driven shaft 52, and is further input to the ring gear 62 via the gear 60. is,
The rotational force is then transmitted to the output shafts 76 and 78 by the action of the differential device 70. During the above power transmission,
The forward clutch 4 is engaged and the reverse clutch 24 is engaged.
is released, the drive shaft 8 is connected to the input shaft 2
The output shafts 76 and 78 are rotated in the forward direction. Conversely, the forward clutch 4
When the drive shaft 8 is released and the reverse clutch 24 is engaged, the drive shaft 8 rotates in the opposite direction to the input shaft 2, and the output shafts 76 and 78 rotate in the reverse direction.
During this power transmission, by moving the movable conical plate 44 of the driving pulley 6 and the movable conical plate 58 of the driven pulley 51 in the axial direction to change the radius of the contact position with the V-belt 50, the driving pulley 6 and the driven pulley 51 can be changed. For example, if the width of the V-shaped pulley groove of the driving pulley 6 is expanded and the width of the V-shaped pulley groove of the driven pulley 51 is reduced, the radius of the V-belt contact position on the driving pulley 6 side becomes smaller, and the driven pulley 51 The radius of the V-belt contact position on the side becomes larger, and a larger gear ratio can be obtained as a result. If the movable conical plates 44 and 58 are moved in the opposite direction, the gear ratio will become smaller, in the exact opposite way to the above.

Next, a hydraulic control device for this continuously variable transmission will be explained. The hydraulic control device is as shown in Figure 2.
Oil pump 10, line pressure regulating valve 102, manual valve 104, speed change control valve 106, clutch fully engaged control valve 108, speed change motor 110, speed change operation mechanism 112, throttle valve 114, starting valve 116, start adjustment valve 118, maximum gear ratio holding valve 120, reverse inhibitor valve 122,
It consists of a lubricating valve 124 and the like.

As described above, the oil pump 10 is driven by the input shaft 2 to suck oil in the tank 130 through the strainer 131 and discharge it into the oil path 132. The oil discharged from the oil passage 132 is supplied to the line pressure regulating valve 10.
2 ports 146d and 146e, and the pressure is regulated to a predetermined line pressure as described later. The oil passage 132 is connected to a port 192c of the throttle valve 114 and a port 172b of the speed change control valve 106.
It also communicates with Further, the oil passage 132 also communicates with the driven pulley cylinder chamber 56, that is,
Line pressure is always supplied to the driven pulley cylinder chamber 56.

The manual valve 104 has four ports 134a,
Valve hole 1 with 134b, 134c and 134d
34, and a spool 136 having two lands 136a and 136b corresponding to the valve hole 134. Spool 136 operated by driver's seat select lever (not shown)
has five stop positions: P, R, N, D and L ranges. Port 134a is a drain port, and port 134b communicates with port 240c of reverse inhibitor valve 122 via oil passage 138. Also, the port 134c is connected to the oil passage 140.
Port 204 of starting valve 116 by
a, and the port 134d communicates with the piston chamber 36 of the forward clutch 4 through an oil passage 142. When the spill 136 is in the P position, the oil passage 1 is controlled by the starting valve 116, which will be described later.
The port 134c to which the starting pressure of 40°C is applied is closed by the land 136b, and the piston chamber 36 of the forward clutch 4 is connected to the oil passage 142 and the port 134c.
34d, and the piston chamber 38 of the reverse clutch 24 is drained through the oil passage 144, the ports 240b and 2 of the reverse inhibitor valve 122.
40c, oil passage 138 and port 134b. When the spool 136 is in the R position, the ports 134b and 134c communicate between the lands 136a and 136b, and the piston chamber 38 of the reverse clutch 24 (when the reverse inhibitor valve 122 is in the upper half state in the figure) is supplied with the starting pressure of the oil passage 140, while the piston chamber 36 of the forward clutch 4 is drained via the port 134d. Spool 136
When the port 134c is in the N position, the port 134c is connected to the land 13.
6a and 136b and cannot communicate with other ports, while port 134b
and 134d are drained together, so that the piston chamber 38 of the reverse clutch 24 and the piston chamber 36 of the forward clutch 4 are both drained as in the P position. When spool 136 is in the D or L position, port 134c and port 134
d communicates between lands 136a and 136b to supply line pressure to the cylinder chamber 36 of the forward clutch 4, while the piston chamber 38 of the reverse clutch 24 is drained through port 134b. This results in the forward clutch 4 being in the P or N position when the spool 136 is in the P or N position.
Both the reverse clutch 24 and the reverse clutch 24 are released and power transmission is interrupted, and the rotational force of the input shaft 2 is not transmitted to the drive shaft 8. When the spool 136 is in the R position, the reverse clutch 24 is engaged (reverse inhibitor is activated). When the valve 122 is in the upper half state in the figure), the output shaft 7
6 and 78 are driven in the backward direction as described above,
When the spool 136 is in the D or L position, the forward clutch 4 is engaged and the output shafts 76 and 78 are driven in the forward direction. In addition,
As mentioned above, there is no difference between the D position and the L position in terms of the hydraulic circuit, but both positions are electrically detected and the shift motor 110 (described later) is used to change speed according to different shift patterns. operation is controlled.

The line pressure regulating valve 102 has six ports 146
a, 146b, 146c, 146d, 146e and 146f, and the valve hole 14
6, five lands 148a, 148b,
Spool 148 having 148c, 148d and 148e and axially movable sleeve 150
and two springs 152 and 15 provided in parallel between the spool 148 and the sleeve 150.
It consists of 4 and. The sleeve 150 is configured to receive a pressing force from one end of a lever 158 that swings about a pin 156. Lever 15
The other end of the drive pulley 6 is engaged with a groove provided on the outer periphery of the movable conical plate 44 of the drive pulley 6. Therefore, as the gear ratio increases, the sleeve 150 moves to the right in the figure, and as the gear ratio decreases, the sleeve 150 moves to the left in the figure. Of the two springs 152 and 154, the outer spring 152 always has both ends connected to the sleeve 150 and spool 14, respectively.
8 and is in a compressed state, but the spring 154 on the inner peripheral side is configured to be compressed only after the sleeve 150 moves a predetermined amount or more in the right direction in the figure. The port 146a of the line pressure regulating valve 102 is connected to the port 17 of the speed change control valve 106 via an oil passage 160.
It is connected to 2a. Throttle pressure is supplied to the port 146b from an oil passage 162 which is a throttle pressure circuit. The port 146c communicates with an oil passage 164 that is a lubrication circuit. port 146d
and 146e is an oil passage 132 which is a line pressure circuit.
Line pressure is supplied from. port 146f
is the drain port. In addition, port 146
Orifices 166, 168 and 170 are provided at the inlets of ports a, 146b and 146e, respectively. In the end, the spool 1 of this line pressure regulating valve 102
48 includes the force due to spring 152 (or the force due to springs 152 and 154), port 14
6a acts on the area difference between lands 148a and 148b; and the port 146b oil pressure (throttle pressure) acts on the area difference between lands 148b and 148c.
A leftward force of the hydraulic pressure (line pressure) of the port 146e acting on the area difference between the lands 148d and 148e acts on the spool 148.
The line pressure of the port 146e is controlled by adjusting the amount of oil leaking from the port 146d to the port 146c so that the forces in the left and right directions are always balanced. Therefore, the line pressure increases as the gear ratio increases, and the higher the oil pressure at port 146a (this oil pressure only acts during sudden gear changes as described later, and is the same oil pressure as the line pressure), the higher the line pressure increases. The higher the throttle pressure acting on the To adjust the line pressure in this way, the larger the gear ratio, the greater the pulley's pushing force against the V belt.
In addition, it is necessary to rapidly supply oil to the pulley cylinder chamber during sudden gear changes, and the higher the throttle pressure (in other words, the lower the negative pressure in the engine intake pipe), the greater the engine output torque. This is to increase the pressure and increase the power transmission torque due to friction.

The speed change control valve 106 has four ports 172a,
Valve hole 1 with 172b, 172c and 172d
72, a spool 174 having three lands 174a, 174b, and 174c corresponding to the valve hole 172, and a spring 175 that pushes the spool 174 to the left in the figure. port 17
2a communicates with the port 146a of the line pressure regulating valve 102 via the oil passage 160 as described above,
The port 172b is the oil line 132 which is a line pressure circuit.
Line pressure is supplied through communication with land 1.
72c is the maximum gear ratio holding valve 1 via the oil passage 176.
The port 172d is in communication with the oil passage 164 which is a lubricating circuit. Note that an orifice 177 is provided at the entrance of the port 172d. The left end of the spool 174 is connected by a pin 181 to approximately the center of a lever 178 of a shift operation mechanism 112, which will be described later.
The axial length of the land 174b is somewhat smaller than the width of the port 172c. Therefore, port 1
The line pressure supplied to the port 172b flows into the port 172c through the gap between the left side of the land 174b and the port 172c, but part of it flows between the right side of the land 174b and the port 172c.
The pressure in the port 172c is determined by the ratio of the areas of the two gaps. Therefore, as the spool 174 moves to the right, the clearance on the line pressure side of the port 172c becomes larger and the clearance on the discharge side becomes smaller.
The pressure at c gradually increases. port 172
The oil pressure of c is from the oil passage 176 and the maximum gear ratio holding valve 12.
0 (however, in the lower half state in the figure) and is supplied to the drive pulley cylinder chamber 42 via the oil passage 180.
Therefore, the drive pulley cylinder chamber 4 of the drive pulley 6
2 becomes higher and the width of the V-shaped pulley groove becomes smaller. On the other hand, although the line pressure is always supplied to the driven pulley cylinder chamber 56 of the driven pulley 51 from the oil passage 132, the pressure received by the driven pulley cylinder chamber 56 increases. Since the area is approximately 1/2 of the pressure-receiving area of the drive pulley cylinder chamber 42, the V-belt pressing force is relatively small compared to the drive pulley 6 side, and the width of the V-shaped pulley groove becomes large. That is, the V-belt contact radius of the drive pulley 6 becomes larger and the V-belt contact radius of the driven pulley 51 becomes smaller, so that the gear ratio becomes smaller. Conversely, when the spool 172 is moved to the left, the effect is completely opposite to that described above.
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 by the pin 181 at approximately the center thereof, but one end of the lever 178 is connected to the lever 15 described above.
8 and the end of the side that contacts the sleeve 150 and the pin 1
83 (for convenience of illustration, the pin 183 on the lever 158 and the lever 17
The other end is connected to the rod 182 by a pin 185.
Rod 182 has a rack 182c that meshes with pinion gear 110a of variable speed motor 110. In such a speed change operation mechanism 112, when the rod 182 is moved, for example, to the right by rotating the pinion gear 110a of the speed change motor 110 controlled by the speed change control device 300, the lever 178 moves with the pin 183 as a fulcrum. It rotates counterclockwise to move the spool 174 of the speed change control valve 106 connected to the lever 178 to the right. As a result, as described above, the movable conical plate 44 of the drive pulley 6 moves to the right, the V-shaped pulley groove interval of the drive pulley 6 becomes smaller, and at the same time, the V-shaped groove of the driven pulley 51 becomes smaller. The distance between the grooves of the shaped pulleys becomes larger,
The gear ratio becomes smaller. One end of the lever 178 is connected to the lever 158 by a pin 183, so when the movable conical plate 44 moves to the right and the lever 158 rotates counterclockwise, the lever 1
Lever 1 with pin 185 on the other end of 78 as a fulcrum
78 rotates counterclockwise. Therefore, the spool 174 is pulled back to the left, and the drive pulley 6
and attempts to bring the driven pulley 51 into a state where the gear ratio is large. Due to this operation, the spool 17
4. The drive pulley 6 and the driven pulley 51 are stabilized at a predetermined speed ratio in accordance with the rotational position of the speed change motor 110. The same applies when the speed change motor 110 is rotated in the opposite direction (note that the rod 182 can move further to the left (overstroke region) in the figure beyond the position corresponding to the maximum speed ratio; , the shift reference switch 298 is activated, and this signal is input to the shift control device 300). Therefore, variable speed motor 1
10 is operated according to a predetermined speed change pattern, the speed ratio changes accordingly, and by controlling the speed change motor 110, the speed change of the continuously variable transmission can be controlled.

Note that when the speed change motor 110 is rapidly operated to the larger speed ratio side, the spool 17 of the speed change control valve 106
4 is temporarily moved to the left side in the figure (however, as the gear shift progresses, it gradually returns to the center position). When the spool 174 moves significantly to the left,
Ports 172a and 172b communicate between lands 174a and 174b, and line pressure is supplied to oil passage 160. The line pressure of the oil passage 160 acts on the port 146a of the line pressure regulating valve 106, increasing the line pressure as described above. That is, when the gear ratio is rapidly changed to the larger gear ratio side, the line pressure becomes higher. Thereby, oil can be rapidly fed into the driven pulley cylinder chamber 56, and the speed can be changed quickly.

The rotational position of the speed change motor (the term "step motor" will be used in the following description) 110 is determined in response to a pulse number signal sent from the speed change control device 300. Gear shift control device 3
The pulse number signal from 00 is given according to a predetermined speed change pattern.

The clutch full engagement control valve 108 has its valve body integrally formed with the rod 182 of the speed change operation mechanism 112. In other words, the clutch fully engaged control valve 1
08 is a valve hole 186 having ports 186a and 186b, and a land 182 formed on the rod 182.
a and 182b. port 186
a communicates with the aforementioned pitot tube 48 through an oil passage 188. That is, a signal hydraulic pressure corresponding to the rotational speed of the drive pulley 6 is supplied to the port 186a. Port 186b communicates with port 204e of starting valve 116 via oil passage 190. Normally, the ports 186a and 186b communicate between the lands 182a and 182b, but the rod 182 moves beyond the position corresponding to the maximum gear ratio (the position where the gear change reference switch 298 is turned on) and into the overstroke region. Port 186a is blocked only when port 186
b is designed to be drained. That is,
The clutch complete engagement control valve 108 normally outputs the rotational speed signal oil pressure of the drive pulley 6 to the starting valve 1.
16 ports 204e, and has a function of stopping the supply of the signal hydraulic pressure when the rod 182 exceeds the maximum gear ratio position and moves into the overstroke region.

The throttle valve 114 has ports 192a and 19
a spool 194 having three lands 194a, 194b and 194c corresponding to the valve holes 192; a spring 196 that pushes the spool 194 to the right in the figure; and a negative pressure diaphragm 198 that applies a force. 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), and the negative pressure in the engine intake pipe is lowered to a predetermined value. If the value is higher than this value, no force is applied at all. Port 192a communicates with oil passage 164, which is a lubricating circuit, and ports 192b and 1
92d communicates with an oil passage 162 which is a throttle pressure circuit, and a port 192c communicates with an oil passage 132 which is a line pressure circuit.
e is a drain port. An orifice 202 is provided at the entrance of the port 192d. The spool 194 is subjected to a force directed to the right in the figure, which is the force of the spring 196 and a force caused by the negative pressure diaphragm 198, and a force directed to the left in the figure, which is the force due to the hydraulic pressure of the port 192d acting on the area difference between the lands 194b and 194c. However, the throttle valve 114
is the port 192 so that the forces in both directions are balanced.
A well-known pressure regulating action is performed using the line pressure c as a pressure source and the port 192a as a discharge port. As a result, a throttle pressure corresponding to the force exerted by the spring 196 and the negative pressure diaphragm 198 is generated in the ports 192b and 192d. The throttle pressure obtained in this way is regulated in accordance with the engine intake pipe negative pressure, and therefore corresponds to the engine output torque. That is, if the engine output torque is large, the throttle pressure will also be correspondingly high.

The starting valve 116 has ports 204a,
A valve hole 204 having lands 204b, 204c, 204d and 204e, and lands 206a, 206b,
Spool 206 with 206c and 206d
(The left side portion of the land 206a in the figure is tapered in diameter) and a spring 208 that pushes the spool 206 to the right in the figure. The port 204a communicates with an oil passage 140 connected via an orifice 210 to an oil passage 162 that is a throttle pressure circuit. The port 204b is drained via an oil passage 200 (this oil passage communicates between the oil pump 10 and the strainer 131), which is a drain circuit. port 2
04c is the start adjustment valve 11 via the oil passage 212.
8 is connected. Port 204d is oil passage 21
4 communicates with the aforementioned pitot tube 20.
That is, a signal hydraulic pressure corresponding to the rotational speed of the input shaft 2 (that is, an engine rotational speed signal hydraulic pressure) is supplied to the port 204d. port 204
The port e communicates with the port 186b of the clutch full engagement control valve 108 through the oil passage 190, as described above. Orifices 216 are provided at the entrances of ports 204c, 204d, and 204e, respectively.
218 and 220 are provided. The starting valve 116 has a function of discharging oil from the port 204a to the port 204b according to the position of the spool 206, thereby setting the oil pressure (starting pressure) in the oil passage 140 to a pressure lower than the throttle pressure.
That is, when the spool 206 is located on the left side in the figure, the port 204a is connected to the port 204a.
Since the clearance from port 204a to port 204b is small, the oil pressure at port 204a is high.Conversely, when the spool 206 moves to the right in the figure, the clearance from port 204a to port 204b increases, increasing the amount of oil leaking from port 20.
4a oil pressure becomes low. Note that the oil passage 162 is the throttle pressure circuit and the oil passage 1 is the start pressure circuit.
40 through the orifice 210, even if the oil pressure in the oil path 140 becomes low, the oil path 1
62 throttle pressure is substantially unaffected.
The position of the spool 206 is determined by the rightward force of the spring 208 and the force due to the hydraulic pressure (start adjustment pressure) acting on the area difference between the lands 206b and 206c, and the force of the port 204d acting on the area difference between the lands 206c and 206d. Force and land 206d due to oil pressure (engine rotation speed signal oil pressure)
It is determined by the balance with the leftward force of the oil pressure of the port 204e (driving pulley rotation speed signal oil pressure) acting on the port 204e. That is, the higher the start adjustment pressure in the oil passage 212 obtained by the start adjustment valve 118 (described later), the lower the start pressure in the oil passage 140, and the higher the engine rotation speed signal oil pressure and drive pulley rotation speed signal oil pressure, the lower the start pressure. becomes higher. At the time of starting, the rod 182 of the aforementioned fully engaged clutch control valve 108 has moved to the farthest left, and the oil passage 190 has been drained, so that the port 204 of the starting valve 116 has moved to the farthest left.
The drive pulley rotation speed hydraulic signal does not act on e. Therefore, the start pressure is controlled by the start adjustment pressure and the engine speed signal oil pressure, and gradually increases as the engine speed increases. This starting pressure is supplied to the forward clutch 4 (or the reverse clutch 24), which is gradually engaged to enable a smooth start. When the start progresses to a certain extent, the clutch full engagement control valve 108 is switched by the action of the step motor 110, and the drive pulley rotation speed signal oil pressure is supplied to the port 204e through the oil passage 190, and the start pressure increases rapidly. As a result, the forward clutch 4
(or the reverse clutch 24) is securely engaged,
There will be no slippage. Note that the starting valve 116 regulates the throttle pressure according to the engine output torque supplied to the port 204a and supplies it to the forward clutch 4 and the reverse clutch 24. No high hydraulic pressure is required. This is suitable for the durability of the forward clutch 4 and the reverse clutch 24.

The start adjustment valve 118 is operated by a force motor 224 that can adjust the amount of oil discharged from the oil passage 212 to a port 222 (this port 222 communicates with the oil passage 200, which is a drain circuit) using a plunger 224a. It is configured. Oil road 212
The oil passage 164, which is a lubricating oil passage, is connected to the orifice 2.
Low pressure oil is supplied via 26. The force motor 224 rotates the oil path 2 in inverse proportion to the amount of current supplied to the force motor 224.
In order to discharge the oil of 12, the oil pressure (start adjustment pressure) of the oil passage 212 is controlled by the amount of energization. The amount of current supplied to the force motor 224 is determined by the speed change control device 30.
Controlled by 0. When the vehicle is stopped and idling, this start adjustment valve 118
The start pressure (hydraulic pressure regulated by the starting valve 116) is controlled by the start adjustment pressure obtained by Ru. Since this start pressure is always supplied to the forward clutch 4 or reverse clutch 24 before starting, the forward clutch 4 or reverse clutch 24 immediately starts to engage as the engine speed increases, and the engine speed increases. The engine will not run dry, and will not start erroneously even if the engine's idling speed is higher than normal.

The maximum gear ratio holding valve 120 has ports 230a,
230b, 230c, 230d, 230e and 2
A valve hole 230 having a diameter of 30f, a land 232a,
Spool 232 with 232b and 232c
and a spring 234 that pushes the spool 232 to the left in the figure. The drive pulley rotation speed signal oil pressure is guided from the oil passage 188 to the port 230a, and the port 230c communicates with the drive pulley cylinder chamber 42 and the port 240d of the reverse inhibitor valve 122 through the oil passage 180.
Further, the port 230d communicates with a port 172c of the speed change control valve 106 via an oil passage 176. Port 230b is drained via oil passage 200, and port 230f is a drain port. Orifices 236 and 238 are provided at the entrances of ports 230a and 230e. land 2
32a and 232b have the same diameter, and the land 232
c has a smaller diameter than these. This maximum gear ratio holding valve 120 is a valve that achieves the maximum gear ratio at the time of starting regardless of the state of the gear change control valve 106. As a result, even if the speed change control valve 106 is fixed at the small speed ratio side due to a failure of the step motor 110 or the like, it is possible to start the vehicle with the maximum speed change ratio. When the vehicle is stopped, the drive pulley rotation speed signal oil pressure is 0, so the spool 23
There is no force pushing spool 2 to the right in the diagram, and the spool 2
32 is pushed by a spring 234 and is in the state shown in the upper half of the figure. Therefore, the drive pulley cylinder chamber 42 is drained via the oil passage 180, port 230c, port 230b, and oil passage 200, and the continuously variable transmission is always in the maximum gear ratio state. In this state, the land 232 of the spool 232
The rightward force in the figure due to the oil pressure of port 230a (driving pulley rotation speed signal oil pressure) acting on the area of a is the force due to the oil pressure of port 230e (engine rotation speed signal oil pressure) acting on the area difference between lands 232b and 232c, and This is maintained until the leftward force of spring 234 is overcome. That is, the forward clutch 4 starts to be engaged, and the drive pulley 6 begins to rotate at a certain speed (that is, the slippage of the forward clutch 4 becomes smaller).
Until then, the maximum gear ratio remains. When the drive pulley 6 begins to rotate at a speed higher than a predetermined speed, the maximum gear ratio holding valve 120 switches to the lower half position in the figure.
Since the ports 230c and 230d communicate with each other, hydraulic pressure from the speed change control valve 106 is supplied to the drive pulley cylinder chamber 42, and the continuously variable transmission becomes able to change speeds. Spool 23 of maximum gear ratio holding valve 120
2 suddenly reaches the state shown in the lower half of the figure, the hydraulic pressure that was acting on the area difference between the lands 232b and 232c is drained from the port 230f. It does not return to the position shown in the upper half until it is lower. That is, just before the vehicle speed becomes very low and the vehicle stops, the spool 232 returns to the position shown in the upper half and enters the maximum gear ratio state. Note that the drive pulley rotation speed signal oil pressure is 0 when the drive pulley 6 is rotating in the opposite direction (that is, when the reverse clutch 24 is operating), so the maximum gear ratio is always maintained even when reversing. state.

Reverse inhibitor valve 122 is connected to port 24
0a, 240b, 240c and 240d, and lands 242a and 242 of equal diameter.
It consists of a spool 242 having a diameter of 1.b and a spring 244 that pushes the spool 242 to the right in the figure. Port 240a is a drain port;
The port 240b communicates with the piston chamber 38 of the reverse clutch 24 via an oil passage 144, and the port 240c communicates with the manual valve 10 via an oil passage 138.
4 port 134b, and port 24
0d is connected to an oil passage 180 that supplies hydraulic pressure to the drive pulley cylinder chamber 42. This reverse inhibitor valve 122 is a valve that prevents the reverse clutch 24 from operating when the manual valve 104 is mistakenly selected to the R position during forward travel. When the vehicle is stopped, the hydraulic pressure in the oil passage 180 (that is, the drive pulley cylinder chamber 42) is drained by the action of the maximum gear ratio holding valve 120 described above. Therefore, since no leftward force in the figure acts on the spool 242 of the reverse inhibitor valve 122, the spool 242 is moved by the spring 242.
44 and is in the position shown in the upper half of the figure, and the ports 240b and 240c are in communication. When the manual valve 104 is selected to the R position in this state, the hydraulic pressure in the port 134b of the manual valve 104 is supplied to the piston chamber 38 of the reverse clutch 24 via the oil passage 138, port 240c, port 240b, and oil passage 144. . This causes the reverse clutch 24 to actuate, resulting in the reverse state. but,
While the vehicle is traveling forward, the maximum gear ratio holding valve 120 is in the position shown in the lower half of the figure until just before the vehicle stops, and oil pressure is supplied to the oil passage 180 from the oil passage 176. Since this oil pressure acts on the port 240d of the reverse inhibitor valve 122, the reverse inhibitor valve 122 is in the state shown in the lower half of the figure.
Communication between oil passages 138 and 144 is blocked, and the oil pressure in piston chamber 38 of reverse clutch 24 is transferred to port 2.
It is drained from 40a. Therefore, even if the manual valve 104 is selected to the R position in this state, no hydraulic pressure is supplied to the piston chamber 38 of the reverse clutch 24. Thereby, it is possible to prevent the power transmission mechanism from moving backward and being damaged during forward travel.

The lubrication valve 124 has ports 250a, 250b,
It consists of a valve hole 250 having holes 250c and 250d, a spool 252 having lands 252a and 252b of equal diameter, and a spring 254 that pushes the spool 252 to the left in the figure. port 25
0a is an oil passage 16 communicating with the downstream side of the cooler 260
The port 250b is connected to an oil passage 162 which is a throttle pressure circuit, the port 250c is connected to an oil passage 258 that communicates with the upstream side of the cooler 260, and the port 250d is a drain circuit. It is connected to a certain oil passage 200. The lubrication valve 124 uses the throttle pressure of the port 250b as a hydraulic pressure source and uses a well-known pressure regulating function to maintain the oil pressure of the port 250a at a constant oil pressure corresponding to the spring 254, and supplies this to the oil passage 164. The oil in oil passage 164 is used to supply and lubricate rotary canals 16 and 46, and then drained to tank 130.

Next, the speed change control device 300 that controls the operation of the step motor 110 and the force motor 224 will be explained.

As shown in FIG. 3, the shift control device 300 includes an engine speed sensor 301, a vehicle speed sensor 302, a throttle opening sensor (or intake pipe negative pressure sensor) 303, a shift position switch 304, a shift reference switch 298, Engine coolant temperature sensor 306, brake sensor 30
7. Electric signals from the start pressure detection pressure sensor 321 and the drive pulley rotation speed sensor 1001 are input. Engine speed sensor 301
detects the engine rotation speed from the engine ignition pulse, and also detects the vehicle speed sensor 302.
detects vehicle speed from the rotation of the output shaft of the continuously variable transmission. A throttle opening sensor (or intake pipe negative pressure sensor) 303 detects the throttle opening of the engine as a voltage signal (in the case of an intake pipe negative pressure sensor, the intake pipe negative pressure is detected as a voltage signal). The shift position switch 304 detects which position of the above-mentioned manual valve 104 is located among P, R, N, D, and L. Shift reference switch 298
is a switch that is turned on when the rod 182 of the aforementioned speed change operation mechanism 112 reaches the position where the speed change ratio is the highest (note that the rod 182 must be moved further while the speed change reference switch 298 is turned on; i.e. overstroke is possible). Engine coolant temperature sensor 306 generates a signal when the engine coolant temperature is below a certain value. Brake sensor 307 detects whether the vehicle's brakes are being used. The start pressure detection pressure sensor 321 is connected to the oil passage 14 described above.
Converts a starting pressure of 0 into an electrical signal. Signals from the engine rotation speed sensor 301, vehicle speed sensor 302, and drive pulley rotation speed sensor 1001 are transmitted to waveform shapers 308, 309, and 10, respectively.
The voltage signal from the throttle opening sensor (or intake pipe negative pressure sensor) 303 is converted into a digital signal by the AD converter 310 and sent to the input interface 311 through the AD converter 310. The speed change control device 300 includes an input interface 311, a CPU
(Central processing unit) 313, reference pulse generator 31
2. ROM (read only memory) 314, RAM
(random access memory) 315, and an output interface 316, which are communicated by an address bus 319 and a data bus 320. The reference pulse generator 312 is
A reference pulse for operating the CPU 313 is generated. The ROM 314 stores programs for controlling the step motor 110 and the force motor 224, as well as data necessary for the control.
The RAM 315 temporarily stores information from each sensor and switch, parameters necessary for control, and the like. The output signal from the speed change control device 300 is
Step motor 110 and force motor 2 via amplifier 317 and current controller 318, respectively.
24.

Next, the step motor 110 and the force motor 2 are operated by this speed change control device 300.
The specific contents of control No. 24 will be explained.

The control is roughly divided into a force motor control routine 500, a complete engagement control routine 600,
The routine consists of a step motor control routine 700.

First, control of the force motor 224 will be explained. A force motor control routine 500 is shown in FIG. Force motor control routine 500
has the function of adjusting the start pressure via the start adjustment valve 118 and the starting valve 116 when the engine is idling, and bringing the forward clutch 4 (or the reverse clutch 24) to a state immediately before starting engagement. This force motor control routine 50
0 is performed at regular intervals (that is, the following routine is repeatedly executed within a short period of time). First, the throttle opening TH is read from the throttle opening sensor 303 (step 501).
The engine rotation speed N _E is read from the engine rotation speed sensor 301 (502), and the vehicle speed V is read from the vehicle speed sensor 302 (502).
503), and drive pulley rotation speed sensor 1001
Then, the drive pulley rotational speed Ni is read (504), and then in step 505 it is determined whether the vehicle speed V is less than a predetermined small value _V0 ,
If it is less than the predetermined value V ₀ , it is determined in step 507 whether the throttle opening TH is less than a predetermined small value TH ₀ , and if it is less than the predetermined value TH ₀ (that is, the vehicle is stopped and the engine is in an idling state). Then, proceed to step 509 and read the start pressure Ps from the start pressure detection pressure sensor 321. In addition,
In steps 505 and 507, V>V ₀ or TH>
If it is determined that TH ₀ , the routine proceeds to step 527 and outputs the same force motor current signal as in the previous routine, that is, the current signal just before V>V ₀ or TH>TH ₀ . After reading the start pressure Ps in step 509, the process proceeds to step 511 where the start pressure Ps is set to the upper limit value of the start pressure before starting the target engagement Psu.
Determine whether it is greater than If Ps>Psu, the force motor current signal I of the previous routine
A small value ΔI is added to the current signal value to obtain a new current signal value (step 513). Next, it is determined whether the current signal I is less than or equal to the maximum allowable current signal _I0 (step 515), and if I≦ _I0 , the process directly proceeds to step 527, and if I> _I0 , I= _I0. as (step
517) Proceed to step 527 and output the force motor current signal I. In step 511, Ps≦Psu
In this case, it is determined whether the start pressure is smaller than the target start pressure lower limit value _PsL before starting the engagement (step 519). If Ps≧Ps _L (when combined with the judgment in step 511, Ps _L ≦Ps≦Psu. In other words, the start pressure Ps is between the upper and lower limits of the start pressure before the start of the target fastening), proceed to step 527. The current signal I from the previous routine is output as is.
If Ps<Ps _L in step 519, the minute value △I is subtracted from the force motor current signal I, and this is used as a new current signal I (step 521). Next, in order to prevent the current signal I from becoming negative, Then, determine whether I≧0 (step
523), if I≧0, proceed directly to step 527; if I<0, proceed to step 525 to set I=0.
The process then proceeds to step 527, where the current signal I is output. In the end, through the above series of steps, if the start pressure Ps is larger than the target pre-engagement start upper limit value, the force motor current signal I is increased to lower the start pressure Ps, and the start pressure Ps is set to the target pre-engagement start pressure. When it is smaller than the lower limit value, control is performed to decrease the force motor current signal I and increase the start pressure, and the start pressure Ps is maintained between the upper limit value and the lower limit value of the target pre-engagement start pressure. The target start pressure before the start of engagement is set to the hydraulic pressure immediately before the forward clutch 4 (or the reverse clutch 24) starts to engage (that is, the hydraulic pressure at which engagement starts when slightly higher than this). Therefore, when the engine rotation speed increases from this state, the starting pressure Ps becomes the oil pressure obtained by adding the oil pressure corresponding to the engine rotation speed to the start pressure before starting the target engagement due to the action of the starting valve 116.
A start is performed in which the forward clutch 4 (or the reverse clutch 24) is engaged. This makes it possible to obtain a stable starting operation without any problems such as racing or false starting, regardless of fluctuations in the idle speed of the engine. This is because the engine's idle speed will not match the normal setting value when the engine is running, when the cooler is in use, or when the engine is malfunctioning, but regardless of the idle speed, the starting pressure
This is because Ps is always controlled to be the target start pressure before the start of fastening due to the above action.

Next, the complete engagement control routine 600 will be explained. A complete engagement control routine 600 is shown in FIG. The complete engagement control routine 600 is executed following step 527 of the force motor control routine 500 described above. i.e. step 527
The program then proceeds to step 601, in which the data of the shift reference switch 298 in the current routine is read, in step 602, the data in the shift reference switch 298 in the previous routine is read, and then in step 603, the data in the shift reference switch 298 in the previous routine is read. It is determined whether or not it is on. If the shift reference switch 298 was off in the previous routine, it is determined whether the shift reference switch 298 in the current routine is on (step 604), and if it is on, the complete engagement pulse number data M is set to a constant value M ₀ (step 605) and proceed to step 607. Also, in step 603, the shift reference switch 29 of the previous routine is
8 is on, it is determined whether or not the shift reference switch 298 of this routine is on (step 606). If it is on, the process proceeds to step 607, and in step 607, a search for the fully engaged vehicle speed V _ON is performed. will be carried out. The number of pulses M ₀ corresponds to the position of the step motor 110 immediately before the rod 182 of the speed change operation mechanism 112 moves to the left in FIG. 2 and enters the overstroke region, that is, when the speed change reference switch 298 is turned on. are doing. In this position, the drive pulley rotation speed signal oil pressure is transmitted from the clutch complete engagement control valve 108 to the starting valve 11.
Leads to 6.

Details of the fully engaged vehicle speed search routine 607 are shown in FIG. As shown in Figure 7, the fully engaged vehicle speed V _ON corresponds to each throttle opening.
It is stored in ROM314. In the fully engaged vehicle speed search routine 607, first, the comparison reference throttle opening TH ^* is set to 0 (i.e., idle state).
(691), and the corresponding ROM314
Set address i to characteristic i ₁ (692). Next, the actual throttle opening TH and the comparison reference throttle opening TH ^* are compared (693). If the actual throttle opening TH is smaller than or equal to the comparison reference throttle opening TH ^* , the actual throttle opening
The address of the ROM 314 in which the fully engaged vehicle speed data V _ON corresponding to TH is stored is given with characteristic i ₁ , and the value of the fully engaged vehicle speed data V _ON ¹ at the address of characteristic i ₁ is read out (the same 696). vice versa,
Actual throttle opening TH is comparison standard throttle opening
If it is larger than TH ^* , add a predetermined increment △TH ^* to the comparison reference throttle TH ^* (694),
The characteristic i is also added by a predetermined increment Δi (695).
Thereafter, the process returns to step 693 and the actual throttle opening TH is compared with the comparison reference throttle opening TH ^* . By repeating this series of processes (693, 694, and 695) several times, the actual throttle opening
The characteristic i of the address of the ROM 314 in which the fully engaged vehicle speed data V _ON corresponding to TH is stored is obtained. In this way, the fully engaged vehicle speed data V _ON corresponding to address i is read out, and the process returns.

Next, the fully engaged vehicle speed V _ON read out as described above is compared with the actual vehicle speed V (609), and if the actual vehicle speed V is greater than the fully engaged vehicle speed data V _ON , , in step 610, the engine rotational speed N _E (i.e., the clutch input rotational speed)
It is determined whether the difference between the drive pulley rotational speed Ni (i.e., the clutch output rotational speed) is less than a predetermined value _N0 , and if N _E -Ni≦ _N0 , the complete engagement flag F is set in step 611. set to 1,
Next, in step 613, it is determined whether the complete fastening pulse number data M is _M0 .
If M≠M ₀ , the process advances to step 615. step
615, it is determined whether the timer value T is negative or 0, and if the timer value T is positive, a predetermined subtraction value △T is subtracted from the timer value T and this is used as the new timer value. Set (617), output the same step motor drive signal as in the previous routine (647), and return. This step 617 is repeatedly executed until the timer value T becomes 0 or negative. When the timer value T becomes 0 or negative, that is, when a certain period of time has elapsed, the step motor 11
0 drive signal in the upshift direction by one step (619), set the timer value T to a predetermined positive value _T1 (621), and set the number of pulses M to the current number of pulses of the step motor. Set it again to add 1 (623) and output the step motor drive signal shifted by one step in the upshift direction (647)
Return. As a result, the step motor 11
0 is rotated by one unit in the upshift direction.
By repeating the above routine, the value of M increases, and when it reaches M= _M0 , the process starts from step 613.
Proceed to 651. Note that even if the shift reference switch 298 of the current routine is off in steps 604 and 606, the routine proceeds to step 651.

If V<V _ON in step 609 or N _E −Ni>N ₀ in step 610, the routine searches for vehicle speed data (completely engaged off vehicle speed) V _OFF at which complete engagement should be released (625). Do this.
This search routine 625 is basically the same as the search routine 607 that searches for the fully engaged on-vehicle speed data V _ON (the only difference being the input data as described below), so the explanation will be omitted.

The relationship between the fully engaged on vehicle speed data V _ON and the fully engaged OFF vehicle speed data V _OFF is as shown in FIG. That is, hysteresis is provided as V _ON > V _OFF . This prevents hunting from occurring. In addition, the vehicle speed data V _ON and V _OFF are determined by the throttle opening as shown in Figure 8.
It is preferable to determine it so that it increases corresponding to TH.

Next, the complete engagement off vehicle speed data V _OFF retrieved in step 625 as described above is compared with the actual vehicle speed V (step 627), and if the actual vehicle speed V is small, the complete engagement flag F is set to 0. (629) Proceed to step 631, and if the actual vehicle speed V is large, determine whether the complete engagement flag F is 0 (633)
If F=0, proceed to step 631; if F=1, proceed to step 613 described above. step 631
Then, determine whether the complete engagement pulse number data M is 0, and if M≠0, determine whether the timer value T is 0 or negative (635), and if the timer value T is positive. If so, a predetermined subtraction value ΔT is subtracted to set the timer value T (637), the same step motor drive signal as in the previous routine is output (647), and the routine returns. By repeating this, the subtraction value ΔT is repeatedly subtracted from the timer value T, so that after a certain period of time, the timer value T becomes 0 or negative. When the timer value T becomes 0 or negative, the step motor drive signal is moved one step in the downshift direction (641). Also, the timer value T is set to a predetermined positive value.
Set T ₁ (643), reset the number of pulses M by subtracting 1 from the current number of step motor pulses M (645), and set the step motor drive signal that has been shifted one step in the downshift direction. Output (same
647), return. This causes step motor 110 to rotate one unit in the downshift direction. By repeating the above routine, the value of M will gradually become smaller, and when M=0 is reached, the step will start.
Proceed from step 631 to step 651. In addition, the number of pulses M=
0 means that the rod 182 of the shift operation mechanism 112 is in the second position.
This corresponds to the position of the step motor 110 at the end of the overstroke region that has moved farthest to the left in the figure.

In step 651, it is determined whether the complete engagement flag F is 1, and if F=1, it is determined whether the number of pulses for complete engagement M is _M0 (same as
653). If M≠M ₀ , then return; if M=M ₀ , proceed to step 705 of step motor control routine 700, which will be described later. That is, step motor control routine 700 is executed only when the clutch is fully engaged and M= _M0 .

The operation of the complete engagement control routine 600 will be summarized and explained by case as follows.

First, when the shift reference switch 298 was off in the previous routine and turned on in the current routine (steps 603→604→605→607→609→610). Set the number of pulses M to M ₀ . Then V≧V _ON and N _E
If -Ni≦N ₀ , the step motor 110 does not move. In other words, it remains in the completely fastened state (steps 611→613→651). V<V _ON or N _E −Ni>
If N is ₀ , compare V and V _OFF , and if V≦V _OFF , rotate the step motor 110 toward the overstroke region until M=0 to release the complete engagement (steps 625→627→629→ 631→635→(637)→
641→643→645→647). If V > V _OFF (that is, V _OFF < V < V _ON , which is in the hysteresis range), and if it was fully engaged in the previous routine, M =
Rotate the step motor 110 until M ₀ (complete engagement remains on) (steps 627→633→
613 and below), and if not fully engaged in the previous routine, the step motor 110 is rotated until M=0 (complete engagement remains off) (steps 627→633→631 and below). Note that, as described above, the shift reference switch 298 is connected to the shift operation mechanism 1.
Since the rod 182 of No. 12 is turned on just before the vehicle enters the overstroke region, when the accelerator pedal is suddenly depressed while driving, or a so-called kickdown is performed, the rod 182 moves to the maximum gear ratio and shifts the gear. The reference switch 298 is turned on, but since V>V _ON , the complete engagement is maintained.

Next, if the shift reference switch 298 was off in the previous routine and is also off in the current routine (steps 603→604). Proceed to step 651.

If the shift reference switch 298 was on in the previous routine and is also on in the current routine (step
603→606→607). If V≧V _ON and N _E −Ni≦N ₀ , the step motor 110 is rotated until M=M ₀ is reached (steps 609→610→611→613→615→
(617) → 619 → 621 → 623 → 647), fully tighten the clutch and proceed to step 651. If V<V _ON , then V
V _OFF , and if V≦V _OFF , rotate the step motor 110 until M=0 (complete engagement is considered off) (steps 627→629→631→635→
(637) → 641 → 643 → 645 → 647). If V > V _OFF (that is, if V _OFF < V < V _ON ), and if the engagement was completely turned on in the previous routine, the step motor 110 is rotated until M = M ₀ (steps 627→633→
613 or less), M if the connection was completely off in the previous routine
The step motor 110 is rotated until the value becomes 0 (steps 627→633→631 and below). That is, the fully fastened on or off state as in the previous routine is maintained.

If the shift reference switch 298 was on in the previous routine and off in the current routine (step 603→
606). Proceed to step 651.

The step motor control routine 700 is advanced from step 651 when the engagement is fully on and M=M ₀ as described above.

Next, the control routine 7 for the step motor 110
00 will be explained. A step motor control routine 700 is shown in FIG. This step motor control routine 700 is a complete engagement control routine 60.
0 step 653 is executed if M=M ₀ (ie, executed if the clutch is fully engaged). First, read the shift position from the shift position switch 304 (same as
705). Next, it is determined whether the shift position is in the D position (707), and if it is in the D position, the D range shift pattern search routine (same as 707) is performed.
720).

The D range shift pattern search routine 720 is executed as shown in FIG. Also, step motor pulse number data for the D range shift pattern.
_ND is stored in the ROM 314 as shown in FIG. That is, the vehicle speed is arranged in the horizontal direction of the ROM 314, and the throttle opening is arranged in the vertical direction (vehicle speed increases as you move toward the right, and throttle opening increases as you move downward). (It is made to grow larger). In the D range shift pattern search routine 720, first, the comparison reference throttle opening TH' is set to 0 (that is, the idle state) (721), and the pulse number data when the throttle opening is 0 is stored. There is
Address j ₁ of the ROM 314 is set to characteristic j (722). Next, compare the actual throttle opening TH and the comparison reference throttle opening TH' (the same
723), if the actual throttle opening TH is larger, add a predetermined increment △ to the comparison reference throttle opening TH'.
TH′ is added (724), and the characteristic j is also added by a predetermined increment △
Add j (725). After this, the actual throttle opening TH is again compared with the comparison reference throttle opening TH' (723), and if the actual throttle opening TH is larger, the above-mentioned steps 724 and 725 are performed. Execute step 723 again. After performing this series of processing (steps 723, 724, and 725), when the actual throttle opening TH becomes smaller than the comparison reference throttle opening TH', the characteristic corresponding to the actual throttle opening TH is determined. j is obtained. Next, the same processing as described above is performed for the vehicle speed V (steps 726, 727, 728, 729 and 730). As a result, the characteristic k corresponding to the actual vehicle speed V is obtained. Next, add the characteristic j and k obtained in this way (731) to find the actual throttle opening.
Obtain the address corresponding to TH and vehicle speed V, and
Read the step motor pulse number data N _D from the corresponding address of the ROM 314 shown in Figure 1.
732). The number of pulses N _D thus read indicates the target number of pulses to be set at the current throttle opening TH and vehicle speed V. After reading this number of pulses N _D , the D range shift pattern search routine 720 is terminated and the process returns.

In step 707 shown in FIG. 9, if the gear is not in the D range, it is determined whether the gear is in the L range (709), and if it is in the L range, the L range shift pattern search routine is searched (740). ).
The L range shift pattern search routine 740 is
The configuration is basically the same as the range shift pattern search routine 720, and the only difference is that the step motor pulse number data N _L stored in the ROM 314 is different from the pulse number data N _D for the D range. (The differences between N _D and N _L will be discussed later). Therefore, detailed explanation will be omitted.

As described above, in step 720 or 740,
After searching for the target step motor pulse number data N _D or N _L depending on the shift position, the signal of the shift reference switch 298 is read (778), and it is determined whether the shift reference switch 298 is on or off. (ibid., 779). When the speed change reference switch 298 is in the off state, the current number of pulses N _A of the step motor stored in the RAM 315 is read out (781). This number of pulses N _A is the number of pulses generated by the speed change control device 300 as a signal for driving the step motor 110, and if there is no electrical noise etc., this number of pulses N _{A and the number of pulses N A}
There is always a one-to-one correspondence with the actual rotational position of 0. At step 779, the shift reference switch 29
8 is in the on state, step motor 1
Set the current pulse number N _A of 10 to 0 (same as
780). The shift reference switch 298 is set to be turned on when the rod 182 of the shift operating mechanism 112 is at the maximum gear ratio position. That is, when the speed change reference switch 298 is on, the actual rotational position of the step motor 110 is at the maximum speed ratio position. Therefore, by setting the number of pulses N _A to 0 when the speed change reference switch 298 is on, the number of pulses N _A will correspondingly become 0 when the step motor 110 is at the maximum speed ratio position. Become. By correcting the number of pulses N _A to 0 at the maximum gear ratio position in this way, it is possible to correct the difference between the actual rotational position of the step motor 110 and the number of pulses N _A due to electrical noise, etc. can be matched with each other. Therefore, electrical noise accumulates and changes the actual rotational position and pulse number of the step motor 110.
There is no problem that N _A becomes incompatible.
Next, in step 783, the searched target number of pulses N _D or N _L is compared with the actual number of pulses _NA .

If the actual number of pulses NA and the target number of pulses N _D or N _L are equal, determine whether the target number of pulses N _D or N _L (= number of pulses N _A ) is 0 (same as
785). If the target pulse number N _D or N _L is not 0,
In other words, if the gear ratio is not at its highest,
Outputs the same step motor drive signal (described later) as in the previous routine (811),
Return. If the target pulse number N _D or N _L is 0, the data of the shift reference switch 298 is read (713), and processing is performed depending on whether it is on or off (715). When the shift reference switch 298 is on, the actual pulse number N _A is set to 0 (717),
Further, the step motor timer value T, which will be described later, is set to 0 (718), and the same step motor drive signal as in the previous routine corresponding to the pulse number 0 is output (811). step
If the shift reference switch 298 is off at step 715, steps from step 801 to be described later are executed.

Next, in step 783, if the actual number of pulses N _A is smaller than the target number of pulses N _D or N _L , it is necessary to drive the step motor 110 in the direction of increasing the number of pulses. First, it is determined whether the timer value T in the previous routine is negative or 0 (787), and if the timer value T is positive, the predetermined subtraction value △T is subtracted from the timer value T. is set as a new timer value T (789), outputs the same step motor drive signal as in the previous routine (811), and returns. This step 789 is repeatedly executed until the timer value T becomes 0 or negative. When the timer value T becomes 0 or negative, that is, when a certain period of time has elapsed, the drive signal of the step motor 110 is moved one step in the upshift direction (791), and the timer value T is set to a predetermined value. Set the positive value T to ₁ (793), and add 1 to the current number of pulses NA of the step motor (same as 793).
795), outputs a step motor drive signal that has been shifted one step in the upshift direction (811), and returns. This causes step motor 110 to rotate one unit in the upshift direction.

If the current step motor pulse number N _A is larger than the target pulse number N _D or N _L in step 783, it is determined whether the timer value T is 0 or negative (step 801), and the timer value T is If it is positive, subtract the predetermined subtraction value △T to set the timer value T (same as
803), outputs the same step motor drive signal as in the previous routine (811), and returns. By repeating this, the subtraction value ΔT is repeatedly subtracted from the timer value T, so that after a certain period of time, the timer value T becomes 0 or negative. When the timer value T becomes 0 or negative, the step motor drive signal is moved one step in the downshift direction (805). In addition, the timer value T is set to a predetermined positive value _T1 (807), the current number of step motor pulses NA is decreased by 1 (809), and the step motor is shifted one step in the downshift direction. Outputs the drive signal (811) and returns. This causes step motor 110 to rotate one unit in the downshift direction.

Here, the drive signal for the step motor will be explained. The step motor drive signal is
As shown in the figure. The four output lines 317a, 317b, 317c, and 317d (see Figure 3) wired to the step motor 110 have four signal combinations A to D, A→B→C→D→A. When a drive signal is applied as in the following, the step motor 110 rotates in the upshift direction, and vice versa
When a drive signal is applied from A to D, the step motor 110 rotates in the downshift direction. Therefore, if the four drive signals are arranged as shown in Figure 13, driving from A to B to C to D (upshift) in Figure 12 means moving the signal to the left in Figure 13. It will be the same as In this case, the bit3 signal is moved to bit0. Conversely, in Figure 12, D→C→
To drive from B to A (downshift),
In FIG. 13, this corresponds to moving the signal to the right. In this case, the bit0 signal is moved to bit3.

Output lines 317a, 317 during upshift
FIG. 14 shows the states of the signals at points b, 317c and 317d. Here, the time in each state of A, B, C, and D is equal to the timer value _T1 specified in step 793 or 807.

As mentioned above, when the actual number of pulses (i.e., actual gear ratio) is smaller than the target number of pulses (i.e., target gear ratio), the step motor drive signal
By being moved to the left (791),
It functions as a signal to rotate the step motor 110 in the upshift direction. Conversely, if the actual gear ratio is larger than the target gear ratio, the step motor drive signal is moved to the right (805), thereby functioning as a signal for rotating the step motor 110 in the downshift direction. Also, if the actual gear ratio matches the target gear ratio,
The drive signal is output in the same state as before without moving it in either the left or right direction. In this case, the step motor 110 does not rotate and no gear change is performed, so the gear ratio is held constant.

In step 709 (FIG. 9) described above, if it is not in the L range, that is, if it is in the R, P, or N range, steps 713 and subsequent steps are executed. That is, the operating state of the shift reference switch 298 is read (713), and the operating state of the shift reference switch 298 is read.
Determine whether 8 is on or off (same
715), when the speed change reference switch 298 is on, the actual pulse number N _A indicating the actual number of pulses of the step motor is set to 0 (717), and the step motor timer value T is set to 0 (718). ). Then,
Outputs the step motor drive signal in the same state as the previous routine (811) and returns. If the shift reference switch 298 is in the OFF state at step 715, the steps from step 801 described above are executed. That is, step motor 110 is rotated in the downshift direction. Therefore, in the R, P, and N ranges, the gear ratio is the largest.

Next, the functions of the clutch complete engagement control valve 108 and the starting valve 116 that constitute the present invention will be collectively explained.

The full clutch engagement control valve 108 is switched by a step motor 110 which is controlled by the full engagement control routine 600 of the transmission control system 300 described above. That is, the clutch fully engaged control valve 108 is activated when the vehicle speed is less than the fully engaged vehicle speed or when the difference between the input rotational speed and the output rotational speed of the clutch is larger than a predetermined value (i.e., when the clutch slip is large). It is located at the position shown in the upper half of FIG. 2, and on the other hand, when the vehicle speed is higher than the fully engaged vehicle speed and the slippage of the clutch is less than a predetermined value, it is located at the position shown in the lower half. Therefore, at low vehicle speeds (while starting) or under heavy loads (for example, while climbing a hill), the port 18 of the clutch full engagement control valve 108 is closed.
6b (i.e., oil passage 190) is drained, and port 204e of starting valve 116
is also drained. For this reason, the starting valve 116 is configured such that the port 204a corresponds to the engine rotational speed signal oil pressure acting on the port 204d.
(starting oil pressure regulation state).
Since this start pressure is supplied to the forward clutch 4 (or reverse clutch 24) via the manual valve 104, the clutch operating pressure increases in accordance with the engine rotation speed. As the start progresses, the vehicle speed reaches a predetermined level or higher (in other words, V _ON in Figure 8).
line) and when the slippage of the clutch becomes less than a predetermined value, the clutch complete engagement control valve 108 switches, ports 186a and 186b communicate with each other, and the clutch is completely engaged via the oil passage 190 to the port 204e of the starting valve 116. A drive pulley rotation speed signal hydraulic pressure, which is a fastening signal hydraulic pressure, is supplied. Therefore, the oil pressure (starting pressure) of the port 204a regulated by the starting valve 116 suddenly becomes high (fully engaged oil pressure regulated state), and the forward clutch 4 (or the reverse clutch 24) is completely closed. It is concluded. Thereafter, as long as the vehicle speed does not fall below the V _OFF line in Figure 8, the starting pressure is maintained at a high level even if the engine speed decreases, and the clutch is fully engaged. Therefore, even when the engine speed is low, the vehicle can be driven with the clutch fully engaged. Note that when the vehicle speed falls below V _OFF in Figure 8, the clutch full engagement control valve 108 is switched again to the position shown in the upper half of Figure 2, and the starting pressure decreases, so the clutch is in the released or half-clutch state. Therefore, the engine will not stop.

In the above embodiment, the drive pulley rotation speed sensor 1001 was provided to detect the drive pulley rotation speed Ni.
The drive pulley rotation speed sensor 1001 can also be omitted by calculating from the vehicle speed V. In other words, if the gear ratio is constant, the relationship between the drive pulley rotational speed Ni and the vehicle speed V is uniquely determined, but
Since the gear ratio is always maintained at a constant maximum gear ratio before complete engagement, the drive pulley rotational speed Ni can be easily calculated from the vehicle speed V.
In this case, the drive pulley rotation speed sensor 1001
The price can be reduced by the amount that is no longer needed.

As explained above, the hydraulic automatic clutch control device according to the present invention has two main functions: a starting hydraulic pressure regulating state in which the hydraulic pressure increases in accordance with the engine rotational speed, and a full engagement hydraulic pressure regulating a hydraulic pressure higher than the above mentioned hydraulic pressure. A starting valve that has two pressure regulating states and supplies the regulated hydraulic pressure to the clutch as operating pressure, and a clutch full engagement signal hydraulic pressure that switches between the two pressure regulating states of the starting valve. a fully engaged clutch control valve;
The clutch complete engagement control valve is configured to bring the starting valve into a fully engaged hydraulic pressure regulating state only when the vehicle speed is equal to or higher than the fully engaged vehicle speed and the difference between the input rotational speed and the output rotational speed of the clutch is less than or equal to a predetermined value. Therefore, even when the engine speed is low, it is possible to drive with the clutch fully engaged, and furthermore, the clutch is not suddenly engaged when running under heavy load. This allows the vehicle to run using the region where the engine has a good fuel consumption rate, thereby improving fuel efficiency. Furthermore, it is possible to prevent a shock from occurring due to sudden engagement of the clutch, and also to prevent a reduction in driving force when climbing.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a V-belt type continuously variable transmission, Figure 2
Figure 3 shows the entire hydraulic control system, Figure 3 shows the speed change control system, Figure 4 shows the force motor control routine, Figure 5 shows the complete engagement control routine, and Figure 6 shows the complete engagement. FIG. 7 is a diagram showing the storage arrangement of fully engaged ON vehicle speed data. FIG. 8 is a diagram showing the fully engaged control pattern. FIG. 9 is a diagram showing the step motor control routine. The figure shows the D range shift pattern search routine, Figure 11 shows the storage arrangement of pulse number data, Figure 12 shows the combination of signals of each output line, and Figure 13 shows the arrangement of each output line. FIG. 14 is a diagram showing signals on each output line in the case of upshift. 2...Input shaft, 4...Forward clutch, 6...
Drive pulley, 8... Drive shaft, 10... Oil pump, 12... Drive gear, 14... Driven gear, 16
... Rotation, 18 ... Oil pool, 20 ... Pitot tube, 22 ... Subshaft, 24 ... Reverse clutch,
26, 28, 30, 32, 34... Gear, 36,
38...Piston chamber, 40...Fixed conical plate, 4
2... Drive pulley cylinder chamber, 44... Movable conical plate, 46... Rotating ring, 47... Oil pool, 4
8... Pitot tube, 50... V-belt, 51... Driven pulley, 52... Driven shaft, 54... Fixed conical plate, 56... Driven pulley cylinder chamber, 57... Spring, 58... Movable conical plate , 60...Gear, 62...Ring gear, 64...Differential case,
66, 68... Pinion gear, 70... Differential device, 72, 74... Side gear, 76, 78...
Output shaft, 102... Line pressure regulating valve, 104...
Manual valve, 106... Speed control valve, 108...
Clutch complete engagement control valve, 110...speed change motor, 112...speed change operation mechanism, 114...throttle valve, 116...starting valve, 118...
...Start adjustment valve, 120...Maximum gear ratio holding valve, 122...Reverse inhibitor valve, 124
... Lubricating valve, 130 ... Tank, 131 ... Strainer, 132 ... Oil path, 134 ... Valve hole, 13
6...Spool, 138, 140, 142, 14
4... Oil path, 148... Spool, 150... Sleeve, 152, 154... Spring, 156
...Pin, 158...Lever, 160,162,
164... Oil path, 166, 168, 170... Orifice, 172... Valve hole, 174... Spool, 175... Spring, 176... Oil path, 1
78... Lever, 180... Oil path, 181, 18
3,185...pin, 182...rod, 190
... Oil passage, 192 ... Valve hole, 194 ... Spool, 196 ... Spring, 198 ... Negative pressure diaphragm, 200 ... Oil path, 202 ... Orifice, 204 ... Valve hole, 206 ... Spool, 20
8... Spring, 212, 214... Oil path, 2
16,218,220...orifice, 224...
... Force motor, 226 ... Orifice, 23
2...Spool, 234...Spring, 242
...Spool, 244...Spring, 250...
... Valve hole, 252 ... Spool, 254 ... Spring, 258 ... Oil path, 260 ... Cooler, 29
8... Speed change reference switch, 300... Speed change control device, 301... Engine rotation speed sensor, 30
2... Vehicle speed sensor, 303... Throttle opening sensor (intake pipe negative pressure sensor), 304... Shift position switch, 306... Engine coolant temperature sensor, 307... Brake sensor,
308, 309... Waveform shaper, 310... AD
Converter, 311...Input interface, 31
2... Reference pulse generator, 313... CPU (central processing unit), 314... ROM (read only memory), 315... RAM (random access memory), 316... output interface, 317
...Amplifier, 318...Current controller, 319...
Address bus, 320...Data bus, 321...
...Start pressure detection pressure sensor, 500...Force motor control routine, 600...Full engagement control routine, 607...Full engagement on vehicle speed search routine, 625...Full engagement off vehicle speed search routine, 700...Shift motor control routine, 720
...D range shift pattern search routine, 740
...L range shift pattern search routine.

Claims (1)

[Claims] 1. It has two pressure regulation states: a starting oil pressure regulation state in which the hydraulic pressure increases in accordance with the engine rotational speed, and a full engagement oil pressure regulation state in which the oil pressure higher than the above oil pressure is regulated. , a starting valve that supplies the regulated hydraulic pressure to the clutch as an operating pressure, and a clutch complete engagement control valve that controls a clutch complete engagement signal hydraulic pressure that switches between the two pressure regulating states of the starting valve. The clutch fully engaged control valve brings the starting valve into a fully engaged hydraulic pressure regulating state only when the vehicle speed is equal to or higher than the fully engaged vehicle speed and the difference between the input rotational speed and the output rotational speed of the clutch is less than or equal to a predetermined value. Hydraulic automatic clutch control device switched as follows.