JPH0674841B2 - Shift control device for continuously variable transmission - Google Patents

Description

The present invention relates to a shift control device for a continuously variable transmission.

(B) Conventional Technology As a conventional shift control device for a continuously variable transmission, there is, for example, one disclosed in Japanese Patent Laid-Open No. 58-170958. The shift control device of the continuously variable transmission is configured to start discharging the hydraulic pressure on the drive pulley side at the same time when the brake is depressed to start shifting to the higher gear ratio side. In addition, JP-A-58-
Japanese Patent No. 170959 discloses a shift control device that starts shifting to a higher gear ratio at the same time when the throttle is fully closed. These speed change control devices foresee the engine braking effect by predicting the need for engine braking from a specific operating condition (that is, using the brake or fully closing the throttle) and immediately starting the speed change to the higher gear ratio side. Is what you are trying to get. This makes it possible to obtain the engine braking effect relatively quickly even in the case of a continuously variable transmission having a slow speed change.

(C) Problems to be Solved by the Invention However, the above-described shift control device for a continuously variable transmission includes:
When the brakes are used or when the throttle is fully closed, shifting to the higher gear ratio side is always started.Therefore, shifting is performed more frequently than the driver actually needs, and the engine brake operates, so the driving feeling is improved. There is a problem that it is not preferable. For example, if the amount of depression of the accelerator pedal is reduced by following the running condition of the vehicle ahead, a shift will be performed and engine braking more than intended will be applied.
Smooth driving will be impaired.

On the other hand, in Japanese Patent Application No. 60-44580 filed by the present applicant, there is provided a shift control device for a continuously variable transmission that shifts gears to a higher gear ratio side only when the throttle is rapidly closed. Have been described. This makes it possible to prevent the engine brake from acting more than necessary. However, in the case of this speed change control device for a continuously variable transmission, axially long taper portions are provided on both sides of the land of the spool that controls opening and closing of the port connected to the drive pulley, and the position where the spool is located. Even if it is, the throttle effect is generated for the oil flow through this port, so even if the shift motor is controlled to shift to the higher gear ratio side when a sudden shift is required, it is discharged from the drive pulley. The oil that is subjected to the throttle effect at the port cannot move the movable portion of the drive pulley at a speed higher than a predetermined speed. Therefore, the response of the shift to the higher gear ratio side is poor, and for example, when the wheels are locked by applying a sudden brake, the output shaft does not rotate and the detected vehicle speed becomes 0, and the gear ratio is high. If you step on the accelerator pedal after some time has elapsed after the gear shift was started, the pulley is still shifting to the higher gear ratio side and oil is being discharged from the drive pulley. Since it is on the way, the frictional force does not sufficiently act on the V-belt, so the V-belt slips and power cannot be transmitted.
In addition, the V-belt is worn. The present invention aims to solve such problems.

(D) Means for Solving the Problems The present invention ensures that an oil discharge passage that is not affected by the throttling effect from the drive pulley is ensured in a state where a rapid gear shift to a higher gear ratio side is required. , Solve the above problems. That is, the shift control device according to the present invention includes a drive pulley and a driven pulley, each of which includes a fixed cone plate and a movable cone plate, a V belt wound between the pulleys, a shift motor, and a shaft according to the rotation of the shift motor. A rod that moves in a direction, a shift control valve that can control the hydraulic pressure that acts on the movable cone plates of both pulleys, and a rod that feeds back the movement of the movable cone plate detected by the gear ratio detection member to the shift control valve, It is applied to a continuously variable transmission having a speed change control valve and a link connecting a speed ratio detection member, and the rod has a port connected to an oil passage communicating with a drive pulley and a port for drain. It has a land which is located in the valve hole and which controls the communication state of both ports. The both ports when in the overstroke region is configured relationship such that the communicating state beyond the position corresponding to the large value.

(E) Action When the gearshift motor is rotated when a sudden gearshift to a higher gearshift ratio is commanded while the vehicle is running with the gear ratio relatively small, the spool of the gear shift control valve moves via the link, and the drive pulley moves. The hydraulic pressure acting on the cone begins to be discharged. As the spool moves further into the overstroke region, the hydraulic pressure will begin to drain further through the drain port of the valve hole provided with the rod. Therefore, the hydraulic pressure of the drive pulley is rapidly discharged. As a result, the movable cone plate of the drive pulley moves, the gear ratio detecting member accordingly moves to the higher gear ratio side, and the spool of the gear control valve also moves.
Regardless of this, the open state of the drain port is maintained.

Therefore, the hydraulic pressure of the drive pulley is always discharged rapidly without any throttling effect during the shift to the higher gear ratio side, and a quick shift is performed. For example, even if the brake is suddenly applied and the accelerator pedal is depressed after a relatively short period of time, when the accelerator pedal is depressed, the shift to the higher gear ratio side is completed, and V Since the frictional force can act on the belt, the V-belt does not slip.

(F) Embodiment FIG. 2 shows a power transmission mechanism of a continuously variable transmission to which the present invention is applied. This continuously variable transmission includes a fluid coupling 12, a forward / reverse switching mechanism 15, a V-belt type continuously variable transmission mechanism 29, and a differential device.
56 and the like, the rotation of the output shaft 10a of the engine 10 can be transmitted to the output shafts 66 and 68 at a predetermined gear ratio and rotation direction. This continuously variable transmission has a fluid coupling.
12 (having lock-up oil chamber 12a, pump impeller 12b, turbine runner 12c, etc.), rotating shaft 13, drive shaft 1
4, forward / reverse switching mechanism 15, drive pulley 16 (fixed cone plate 1
8, drive pulley cylinder chamber 20 (composed of chamber 20a, chamber 20b, movable conical plate 22, etc.), planetary gear mechanism 17 (Sun gear 1
9, consisting of pinion gear 21, pinion gear 23, pinion carrier 25, internal gear 27, etc.), V-belt 24,
Driven pulley 26 (fixed cone plate 30, driven pulley cylinder chamber
32, movable cone plate 34, etc.), driven shaft 28, thrust bearing 31, inner race 31a, outer race 31
b, ball 31c, forward clutch 40, drive gear 46, idler gear 48, reverse brake 50, idler shaft 52, pinion gear 54, final gear 44, pinion gear 58, pinion gear 60, side gear 62, side gear 64, output shaft Although it is composed of an output shaft 66, an output shaft 68, etc., detailed description of these components will be omitted. Regarding the configuration of the part of which description is omitted, Japanese Patent Application No. 226706/1984 filed by the applicant
No.

FIG. 1 shows a hydraulic control device for a continuously variable transmission. This hydraulic control device includes an oil pump 101, a line pressure regulating valve 102, a manual valve 104, a shift control valve 106, an adjusting pressure switching valve 108, a shift motor (step motor) 110, a shift operating mechanism 112, a throttle valve 114, a constant pressure. It has a pressure regulating valve 116, a solenoid valve 118, a coupling pressure regulating valve 120, a lock-up control valve 122, etc., which are connected to each other as shown in the drawing, and also have a forward clutch 40, a reverse brake 50, The fluid coupling 12, the lockup oil chamber 12a, the drive pulley cylinder chamber 20, and the driven pulley cylinder chamber 32 are also connected as shown. Detailed descriptions of these valves and the like other than the gear shift control valve 106, the gear shift operation mechanism 112, etc., which are directly related to the present invention, are omitted. The part of which description is omitted is described in the above-mentioned Japanese Patent Application No. 59-226706. Each reference numeral in FIG. 1 indicates the following member. Pinion gear 110a,
Tank 130, strainer 131, oil passage 132, relief valve 133,
Valve hole 134, ports 134a-e, spool 136, land 136a-
b, oil passage 138, one-way orifice 139, oil passage 140, oil passage 14
2, one-way orifice 143, valve hole 146, ports 146a-g,
Spool 148, lands 148a-e, sleeve 150, spring 152, spring 154, gear ratio detection member 158, oil passage 164,
Oil passage 165, orifice 166, orifice 170, valve hole 172, annular ports 172a-e, spool 174, land 174a-c, spring 175, oil passage 176, orifice 177, link 178, oil passage 179, oil passage 180, pin 181, rod 182, land 182a ~
b, rack 182c, lands 182d to e, pin 183, pin 185,
Valve hole 186, ports 186a-f, oil passage 188, oil passage 189, oil passage 19
0, valve hole 192, ports 192a-g, spool 194, land 194
a to e, negative pressure diaphragm 198, orifice 199, orifice 202, orifice 203, valve hole 204, ports 204a to e,
Spool 206, land 206a-b, spring 208, oil passage 20
9, filter 211, orifice 216, port 222, solenoid 224, plunger 224a, spring 225, valve hole 230,
Ports 230a-e, spool 232, lands 232a-b, spring 234, oil passage 235, orifice 236, valve hole 240, port
240a to h, spool 242, land 242a to e, oil passage 243, oil passage 245, orifice 246, orifice 247, orifice 24
8, orifice 249, choke type throttle valve 250, relief valve 251, choke type throttle valve 252, pressure holding valve 253, oil passage 254,
Cooler 256, cooler pressure holding valve 258, orifice 259, changeover detection switch 278.

The shift control valve 106 includes a valve hole 172 having five ports 172a, 172b, 172c, 172d and 172e, and a spool 174 having three lands 174a, 174b and 174c corresponding to the valve hole 172.
It consists of a spring 175 that pushes the spool 174 to the left in the figure. The oil passage 176 is in constant communication with the drive pulley cylinder chamber 20 and the port 186f of the valve hole 186 described later via the port 172b, and the ports 172a and 172e are drain ports. An orifice 177 is provided at the outlet of the port 172a. The port 172d communicates with the driven pulley cylinder chamber 32 via the oil passage 179. The line pressure is supplied to the port 172c by communicating with the oil passage 132 which is a line pressure circuit.
The left end of the spool 174 is the link 17 of the gear shift operation mechanism 112, which will be described later.
A pin 181 is rotatably connected to the substantially central portion of 8. The line pressure supplied to the port 172c flows into the port 172b, but part of this is discharged to the port 172a.
The pressure at the port 172b is a pressure determined by the ratio of the inflowing oil and the discharging oil. Therefore, as the spool 174 moves leftward, the clearance on the line pressure side of the port 172b increases and the clearance on the discharge side decreases, so that the pressure of the port 172b gradually increases. Meanwhile, port 17
The line pressure of the port 172c is normally supplied to 2d.
The oil pressure of the port 172b is supplied to the drive pulley cylinder chamber 20 via the oil passage 176, and the oil pressure of the port 172d is supplied to the oil passage 179.
Is supplied to the driven pulley cylinder chamber 32 via. 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 groove of the drive pulley 16 decreases, while the width of the V-shaped pulley groove of the driven pulley 26 decreases. growing. That is, V of the drive pulley 16
Since the V-belt contact radius of the driven pulley 26 becomes smaller as the belt contact radius becomes larger, the gear ratio becomes smaller.
Conversely, when the spool 174 is moved to the right, the gear ratio is increased due to the effect which is completely opposite to the above.

The link 178 of the speed change operation mechanism 112 is connected to the spool 174 of the speed change control valve 106 by a pin 181 at approximately the center thereof, and one end of the link 178 is connected to a speed ratio detection member 158 and a pin 183. The other end is connected to the rod 182 by a pin 185. Rod 182 is rack 18
The rack 182c is engaged with the pinion gear 110a of the transmission motor 110. Also, the adjustment pressure switching valve
Rod 182 in which lands 182a and 182b of 108 are integrally formed
Also has land 182d and land 182e,
Valve hole 18 with 186a, 186b, 186c, 186d, 186e and 186f
It is fitted in 6 so that it can move axially. In such a shift operation mechanism 112, the pinion gear 1 of the shift motor 110 controlled by a shift control device (not shown).
When the rod 182 is moved to the right in the figure by rotating 10a, the link 178 rotates clockwise about the pin 183 as a fulcrum, and the shift control valve 106 connected to the link 178 is rotated.
Move spool 174 to the right. As a result, the movable cone plate 22 of the drive pulley 16 moves to the left in FIG. 1 and the gap between the V-shaped pulley grooves of the drive pulley 16 increases.
At the same time, the gap between the V-shaped pulley grooves of the driven pulley 26 becomes smaller and the gear ratio becomes larger. Since one end of the link 178 is connected to the gear ratio detecting member 158 by the pin 183, the gear ratio detecting member is moved as the movable cone plate 22 moves.
When 158 moves to the left in Fig. 1, this time link 178
The link 178 rotates in the clockwise direction with the pin 185 on the other end side as the fulcrum. Therefore, the spool 174 is pulled back to the left, and the drive pulley 16 and the driven pulley 26 try to bring the gear ratio into a small state. By such operation spool 17
4, the drive pulley 16 and the driven pulley 26 are stable at a predetermined gear ratio corresponding to the rotational position of the transmission motor 110. The same applies when the transmission motor 110 is rotated in the opposite direction. Therefore, when the speed change motor 110 is operated according to a predetermined speed change pattern, the speed change ratio changes accordingly, and by controlling the speed change motor 110, the speed change of the continuously variable transmission can be controlled. The rod 182 can move further to the right side (overstroke region) in the figure beyond the position corresponding to the maximum value of the gear ratio. The action as described below can be obtained.

The rotation position of the transmission motor 110 is determined according to the pulse number signal sent from the transmission control device. The pulse number signal from the shift control device is given according to a predetermined shift pattern.

Next, the operation of this embodiment will be described.

When the vehicle travels steadily in a state where the gear ratio is relatively small, the spool 174 of the gear shift control valve 112, the rod 182, the gear ratio detecting member 158, and the link 178 are in the state shown in FIG. That is, the rod 182 is in the position shown in the upper half. When the shift motor 110 is rapidly operated to the large shift side in this state, the rod 182 moves to the right in FIG. 1, and the position at the maximum shift ratio side (that is, the shift reference switch 298 is turned on). Position) and move to the overstroke area. Therefore, the rod 182 is in the state shown in the lower half of FIG. 1, and the ports 186f and 186e communicate with each other between the lands 182d and 182e. Therefore, the hydraulic pressure of the drive pulley cylinder chamber 20 is the oil passage 176, the port 186f, and the port 186e.
It is rapidly discharged via. By the movement of the rod 182, the link 178 pivots clockwise in FIG. 1 with the pin 183 as a fulcrum, the spool 174 of the speed change control valve 112 is largely moved to the right in FIG. 1, and the port 172b is moved to the drain port. 172a
The hydraulic pressure of the drive pulley cylinder chamber 20 is also discharged from the drain port 172a in order to communicate with the. In this way, the hydraulic pressure in the drive pulley cylinder chamber 20 is changed to the port 186e and the port 17e.
As the movable conical plate 22 of the drive pulley moves toward the high gear ratio side, that is, to the left in FIG. 1, as it is rapidly discharged from the two places 2a, it finally reaches the position of the highest gear ratio. When the movable conical plate 22 is moved to the position on the maximum gear ratio side, the state in which the ports 186f and 186e are in complete communication is maintained. Therefore, the hydraulic pressure in the drive pulley cylinder chamber 20 rapidly increases without being affected by the throttling effect until the movable cone plate 22 moves to the position with the large gear ratio, that is, until the gear shift to the large gear ratio side is completed. Continues to be discharged. Therefore, the shift to the higher gear ratio side is performed extremely rapidly. As a result, even when the wheels are locked by the sudden braking and the drive pulley and the driven pulley do not rotate, the gear can be rapidly changed, and the V-belt slips even when the vehicle is re-driven after a short time. Occurrence can be prevented.

Thus, according to this embodiment, the land 182 of the rod 182 is
d, 182e, and ports 186f, 186e of the valve hole 186 are sufficient to achieve the purpose, and it is not necessary to add a new valve, actuator, etc., or increase the size of the valve. It is possible to perform highly reliable shift control with almost no increase in

(G) Effect of the Invention As described above, according to the present invention, the sudden change speed toward the large gear ratio side is driven via the drain oil passage formed when the rod moves to the overstroke region. Since the hydraulic pressure of the pulley is rapidly discharged, the gear shift to the higher gear ratio side is performed rapidly. As a result, it is possible to prevent the V-belt from slipping when re-driving from the shift to the higher gear ratio side.

[Brief description of drawings]

FIG. 1 is a diagram showing a shift control device for a continuously variable transmission according to the present invention, and FIG. 2 is a diagram showing a skeleton diagram of the continuously variable transmission. 16 …… Drive pulley, 24 …… V belt, 26 …… Drive pulley, 106 …… Shift control valve, 110 …… Shift motor, 158 ……
Gear ratio detection member, 186e, 186f …… Port, 182d, 182e ……
Land, 178 ... Link, 182 ... Rod.

Claims (1)

[Claims] 1. A drive pulley and a driven pulley, each of which comprises a fixed cone plate and a movable cone plate, a V belt wound between the pulleys, a speed change motor, and a rod which moves in the axial direction in response to rotation of the speed change motor. And a speed change control valve capable of controlling the hydraulic pressure acting on the movable cone plates of both pulleys, and a rod, a speed change control valve and a speed change gear so that the movement of the movable cone plate detected by the speed ratio detecting member is fed back to the speed change control valve. In a transmission control device for a continuously variable transmission having a link connecting a ratio detection member, the rod is arranged in a valve hole having a port connected to an oil passage communicating with the drive pulley and a port for the drain. At the same time, it has a land that controls the communication state of both ports, and the land and the both ports exceed the position where the rod corresponds to the maximum value of the gear ratio. A transmission control device for a continuously variable transmission, characterized in that the two ports are in a communication state when in an overstroke region.