JPS6246063A - Hydraulic control device for speed change gear - Google Patents

Abstract

PURPOSE:To make it possible to adjust the line pressure in several stages, by utilizing a signal hydraulic pressure during direct coupling, a signal hydraulic pressure for a throttle opening degree and a signal hydraulic pressure during abrupt deceleration. CONSTITUTION:Oil from an oil port 40 is effected in a right end chamber 51 and an intermediate port 52 in a regulator valve 50, and is regulated to a desired line pressure by means of a spring 54. A plunger 56 having three lands 56a through 56c is disposed on the left side of a spool 53. A signal hydraulic pressure P1 which is cut off during direct coupling is led from a rock-up control valve 100 into a port 57 while a signal hydraulic pressure P2 which is effected when the throttle opening degree exceeds a predetermined value, is led into a port 58, and a signal hydraulic pressure P3 which is effected during coast- down, is led from a coast-down control valve 70 into a port 59. With these signals P1 through P3 the line pressure may be adjusted in several stages.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a hydraulic control system for a transmission, particularly a transmission in which a direct drive path and a belt drive path are provided in parallel between the driver and the output shaft. The present invention relates to a hydraulic control device that controls hydraulic pressure to a hydraulic chamber for pulley ratio control of a gear shift section.

Prior art and its problems In general, there is a problem that the power transmission efficiency of belt drive is inferior to that of gear drive.
As described in Publication No. 4058, a direct drive path including a direct gear train and a belt drive path including a belt type continuously variable transmission section are provided in parallel between the input shaft and the output shaft,
A mechanism is provided to switch between the direct drive path and the belt drive path, and power is transmitted via the belt drive path in the low speed ratio range.
In the high-speed ratio range, a system has been proposed in which power is transmitted via a direct drive path to improve the power transmission efficiency in the high-speed ratio range, which accounts for most of the running time, and to extend the life of the belt. .

By the way, it is customary for belt heating and pulley ratio control of the transmission section to be performed by a hydraulic control device, and as this hydraulic control device, for example, as described in JP-A-59-1.75664, Equipped with a hydraulic chamber (hydraulic servo) for controlling the pulley ratio provided on one of the driving pulley or the driven pulley, a control valve that supplies and discharges line pressure to the hydraulic chamber, and a regulator valve that regulates the line pressure itself, It is known that a regulator valve regulates line pressure depending on the relationship between engine speed and pulley ratio.

However, the above-mentioned hydraulic control device is for controlling the speed of only the V gear/adult stage transmission section, and if this is applied as is to a transmission that has a direct drive path and a belt drive path, the oil pump's This is not preferable because the ejection loss increases. In other words, there is no need to control the pulley ratio during direct drive, so the oil pressure in the hydraulic chamber can be low.If the same high oil pressure as when belt drive is used during direct drive, the oil during direct drive, which takes up most of the running time, will be used. This is because the discharge loss of the pump is large, which affects fuel efficiency.

In addition, if a sudden deceleration is performed during belt drive, the pulley ratio of the V-belt continuously variable transmission must be quickly shifted to a low speed ratio that allows restart before the vehicle comes to a stop. It is necessary to generate line pressure that is higher than during normal shift control.However, if line pressure was regulated by engine speed or pulley ratio as in the past, agile coast down control would not be possible. It can't be achieved.

Purpose of the Invention The present invention has been made in view of such conventional problems.
The purpose is to provide a hydraulic control device for a transmission that can reduce the discharge loss of an oil pump during direct drive and realize agile coastdown control.

Structure of the Invention In order to achieve the above object, the present invention provides a system in which a directly coupled drive path including a directly coupled gear train and a belt drive path including a V-belt continuously variable transmission section are connected in parallel between an input shaft and an output shaft. In a transmission comprising a switching mechanism for selectively switching between the direct drive path and the belt drive path, a pulley provided on one of the driving pulley or the driven pulley of the V-belt continuously variable transmission section. It includes a hydraulic chamber for ratio control, a control valve that controls hydraulic pressure to the hydraulic chamber, and a regulator valve that supplies line pressure to the control valve, and the regulator valve controls the signal hydraulic pressure and throttle opening when directly connected. The line pressure is regulated in multiple stages using the signal oil pressure corresponding to the current and the signal oil pressure at the time of sudden deceleration.

In other words, during direct drive, the regulator valve regulates the line pressure to a low level using the signal hydraulic pressure during direct coupling to reduce oil pump discharge loss, and when coasting down, the signal hydraulic pressure during sudden deceleration regulates the line pressure higher than when belt drive. This is to realize rapid coastdown control.

DESCRIPTION OF EMBODIMENTS FIG. 1 shows an example of a transmission according to the present invention, in which a fluid coupling cover 2 is coupled to an end of a crankshaft 1 of an engine, and a fluid coupling is configured inside the fluid coupling cover 2. A pump 3, a turbine 4, and a centrifugal lock-up clutch 5 are rotatably housed.

The input shaft 6 is coupled to the turbine 4 and the lock-up clutch 5, and a direct coupling gear 7 constituting a direct coupling gear train is rotatably inserted into the input shaft 6. The shaft 6 is selectively connected to the shaft 6 by a dog clutch 8. The switching sleeve 8a of the dog clutch 8 is connected to an actuator 11 (described later) via a shift fork 32.
Axially actuated by 0.

An external gear 9 is fixed to the end of the input shaft 6, and this external gear 9 meshes with an internal gear 12 fixed to the primary shaft 11 of the V-belt adult stage transmission section 10. The driving force is transmitted to the primary shaft 11 at a reduced speed. ■The belt adult stage transmission unit IO has a driving pulley 13 provided on the secondary shaft 11, a driven pulley 15 provided on the secondary shaft 14, and a bell 116 wound between both pulleys. There is. The drive pulley 13 has a fixed sheep 13a, a movable sheep 13b, and a thrust generator 33 provided behind the movable sheep 13b. are doing. Examples of the thrust generating device 33 include a torque cam that generates a thrust commensurate with the input l/lux, a centrifugal actuator that generates a thrust that corresponds to the rotational speed, and a hydraulic servo that generates a desired thrust using line pressure. .

On the other hand, the driven pulley 15 as well as the driving pulley 13,
It has a fixed sheave 15a and a movable sheave 15b, and a hydraulic chamber 18 for controlling a pulley ratio is provided behind the movable sheave 15b to operate the movable sheave 15b in the axial direction using hydraulic pressure. The hydraulic pressure to this hydraulic chamber 18 is controlled by a hydraulic control device described later.

A driven shaft 19 is rotatably inserted around the outer periphery of the secondary shaft 14 , and the secondary shaft 14 and the driven shaft 19 are connected to each other by a power intermittent clutch 20 . This clutch 20 is also operated by a /111 pressure control device which will be described later, and connects the secondary shaft 14 and the driven shaft 19 when the belt is driven, and disconnects it when the belt is driven. A forward gear 21 is attached to the driven shaft 19.
and the reverse gear 22 are rotatably inserted, and the forward gear 21 or the reverse gear 2 is connected by the forward/reverse switching device 23.
2 is connected to the driven shaft 19.

The reverse idle shaft 24 is disposed parallel to the driven shaft 19, and a reverse idle gear 25 that meshes with the reverse gear 22 and a reverse idle gear 26 are fixed to this shaft 24.

The counter shaft 27 is also arranged parallel to the driven shaft 19,
This counter shaft 27 includes a counter gear 28 that also serves as a direct coupling gear that simultaneously meshes with the direct coupling gear 7, the forward gear 21, and the reverse idle gear 26, and a final reduction gear 29.
are fixed, and the final reduction gear 29 meshes with the differential device 30 to transmit power to the output shaft 31.

In the transmission having the above configuration, the dog clutch 8, the direct coupling gear 7, the counter gear 28. The final reduction gear 29 and the differential device 30 form a direct drive path, while the external gear 9. Internal tooth gear 12, ■ Belt adult stage transmission section 10. Clutch 20, forward gear 21. Counter gear 2
8. Final reduction gear 29. The differential device 30 forms a belt drive path. And the direct coupling gear ratio i between the input shaft 6 and the output shaft 31 in the direct coupling drive path.

is set at a slightly lower speed than the maximum speed ratio between the input shaft 6 and the output shaft 31 in the belt drive path.

Figure 2 illustrates this relationship, where A is the lowest speed line when belt drive, B is the highest speed line when belt drive, and C is the shift line when direct drive. C is located on the slightly lower speed side than the maximum speed line B during belt drive.

Generally, to switch from belt drive to direct drive, first accelerate along the belt drive's lowest speed line A, and when the input rotation speed (or engine rotation speed) reaches a predetermined value, It is sufficient to shift to a high speed side while maintaining the rotational speed 7, and when the gear ratio of the belt drive matches the direct drive gear ratio, the dog clutch 8 is engaged to switch to the direct drive.

A hydraulic control device shown in FIG. 3 is provided to control the speed change of the belt adult stage transmission section 10 as described in -1- and to switch between belt drive and direct drive. In the drawing, 40 is an oil pump, 50 is a regulator valve, 60 is a pulley control valve, 70 is a coastdown control valve that also serves as a kickdown control valve, 80 is a throttle valve, 90 is a clutch control valve, 100 is a lockup control valve, 110 is acticoator,
120 is a control circuit such as a microcomputer, 12]
, 122, 123 are the first . 2nd and 3rd solenoid valves.

The oil pressure sent from the oil tank 41 via the strainer 42 by the oil pump 40 acts on the right end chamber 51 and the intermediate boat 52 of the legico lake valve 50, and the oil pressure in the right end chamber 51 causes the regulator valve 50 to move. The spool 53 moves to the left against the spring 54, and when the land 53a of the spool 53 reaches the position shown in the drawing, the boats 52, 55 are brought into communication and the oil is returned to the suction Ill of the oil pump 40. Therefore, the spool 53
is balanced at this position and the line pressure is regulated to the desired line pressure.

A plunger 56 is installed on the left side of the spool 53, and has three lands 56a, 56b, and 56c whose diameters are successively smaller. The boat 57 is supplied with a signal hydraulic pressure P that is turned OFF when directly connected from the pull-up control valve 100, and the boat 58 is supplied with a signal hydraulic pressure P that is turned off when the throttle opening exceeds a certain value from the throttle valve 80. A signal oil pressure P2 that turns ON is guided,
Furthermore, a signal hydraulic pressure P3 that is turned ON during coast down is introduced to the boat 59 from a coast down control valve 70. Therefore, these signal oil pressures p, , p2+P3
The plunger 56 pushes the spool 53 to the right,
Line pressure can be adjusted in multiple levels.

The pulley control HALPRO 0 has a spool 62 biased to the left by a spring 61.
The right end chamber 63 that accommodates the first solenoid valve 121
Hydraulic pressure (solenoid pressure) is guided by turning ON and OFF.

A boat 65 to which line pressure is introduced and a drain port 66 are formed on both sides of the boat 64, which communicates with the hydraulic chamber 18 of the driven pulley 15. -1- The boat 64 communicating with the hydraulic pressure distribution chamber 18 communicates with the left end chamber 67 via a communication hole 62a formed inside the spool 62, so that the hydraulic pressure in the hydraulic chamber 18 is transferred to the first solenoid valve 121.
When OFF (solenoid pressure 0FF), spring 6
When the first solenoid valve 121 is ON (solenoid pressure ON), the hydraulic pressure is controlled to be balanced with the sum of the spring force of the spring 61 and the solenoid pressure. Therefore, when the first solenoid valve 21 is OFF, the oil pressure in the hydraulic chamber 18 is low and the pulley ratio is controlled to the high speed ratio side, and when it is ON, the oil pressure in the hydraulic chamber 18 is high and the pulley ratio is controlled to the low speed ratio side.

The coastdown control valve 70 has a spool 72 biased leftward by a spring 71, and hydraulic pressure (solenoid pressure) controlled by turning the second solenoid valve 122 ON and OFF is introduced into the left end chamber 73. There is. The coastdown control valve 70 includes a boat 74 communicating with the boat 65 of the pulley control valve 60, a boat 75 communicating with the lock-up control valve +00, a boat 76 communicating with the clutch control valve 90, and a throttle valve 8.
A boat 77 that communicates with the boat 83 of the regulator valve 50, a boat 78 that communicates with the boat 59 of the regulator valve 50, and a boat 79 that communicates with the boat 85 of the throttle valve 80 are formed.
F (When the solenoid pressure is 0FFA, the spool 72 is at the left end position as shown in the figure, and the boats 75 and 76 communicate with each other to guide the line pressure to the clutch control valve 90. At this time, the pulley control valve 60 Boat 74 and boat 75 passing through are blocked, but line pressure is passed through orifice 68 to boat 6 of pulley-controlled hull pro 0.
5, the hydraulic pressure in the hydraulic chamber 1B never becomes zero. On the other hand, when the second solenoid valve 122 is turned on (solenoid pressure is turned on) during coast down or kick down, the spool 72 moves to the right, the board doors 4 and 75 communicate with each other, and the line pressure is sent to the pulley control valve 60. Meanwhile, the connection between boats 75 and 76 is cut off, and the hydraulic pressure to clutch control valve 90 is cut off. In particular, during course 1 to down, the second solenoid valve 122 is turned OFF.
Since the throttle valve 80 is close to fully closed (indicated by the dashed line in the figure), the line pressure is lower than the boat 79.
．． 78 to the boat 59 of the regulator valve 50, and the signal oil pressure P3 is turned ON.

The throttle valve 80 is linked to the accelerator pedal, and when the throttle opening is fully closed or close to fully closed, the spool 82 is moved by the spring 8I as shown by the dashed line.
is in the leftmost position, and the boat 83 leading to the coastdown control valve 70 and the boat 86 leading to the regulator valve 50 are closed and the boat 84 leading to line pressure is closed.
and boat 85 are connected. Further, when the throttle opening is opened, the spool 82 moves to the right and the boat 83.
84. '86 is communicated, the line pressure is guided to the 2]-strokedown control valve 70, and also to the boat 58 of the regulator hull 50, and the signal oil pressure P2 is turned ON. Note that since the boat 85 is drained when the throttle opening is opened beyond a certain level, the signal oil pressure P3 of the boat 59 of the regulator valve 50 is turned OFF regardless of the coast down control valve 70.

The clutch control valve 90 has a boat 91 at its right end that communicates with the boat 76 of the coastdown control valve 70, and the spool 92 is controlled by the hydraulic pressure acting on the boat 91.
moves to the left against a spring 93, thereby selectively switching between a boat 94 to which hydraulic pressure is supplied, a boat 95 leading to the clutch 20, and a drain boat 96. That is, when no hydraulic pressure is applied to the rightmost boat 91, the spool 92 is at the rightmost position, and the boat 91 is at the rightmost position.
4 is closed and the boats 95 and 96 communicate,
The hydraulic pressure of the clutch 20 has been drained and the clutch 20 is disengaged. On the other hand, when hydraulic pressure acts on the boat 91 at the right end, the spool 92 moves to the left and the boats 94 and 95 communicate with each other, and the hydraulic pressure is introduced to the clutch 20, thereby connecting the clutch 20.

The lock-up control valve 100 is actuated by an actuator 110.
This valve controls the left end chamber 1 and has a spool 102 biased leftward by a spring 101.
03 is guided to hydraulic pressure (solenoid pressure) that is controlled by turning the third solenoid valve 123 ON and OFF. The lock-up control valve 100 is formed with 5 (11) boats 104 to 108, and the rightmost boat 1-+
04 communicates with the right ventricle] 11 of the actuator 110,
Line pressure is introduced to the boat 105 , and the boat 106 communicates with the boat 75 of the coast down control valve 70 and the boat 57 of the regulator valve 50 .
communicates with the left chamber 112 of the actuator 110, and the leftmost boat 108 serves as a drain boat. The third solenoid valve 123 is OFF (the solenoid pressure is 0OFF)
), the spool 102 is at the left end position as shown in the figure, the balls 105, 106, and 107 are in communication, and the line pressure is transferred to the left chamber 112 of the actuator 110, the boat 75 of the coast down control valve 70, and the regulator valve 50. It acts on the boat 57. On the other hand, when the third solenoid valve 123 is turned on (the solenoid pressure is turned on), the spool 102 moves to the right, and the boats 104 and 10
5 to supply line pressure to the right chamber Ill of the actuator 110, and when the spool 102 further moves to the right, the boat 106 is drained.

The actuator 110 has a piston l13 that is movable by hydraulic pressure acting on left and right chambers 111 and 112, and a rod 114 that operates the shift fork 32 of the dog clutch 8 is coupled to this piston 113. Further, a spring 115 is housed in the left chamber 112, and constantly urges the piston 113 to the right, that is, in the non-directly connected direction.

The control circuit 120 has an input rotation speed N1 of the input shaft 6 and an output rotation speed N of the output shaft 31. , throttle opening, medium speed, bu 1
A brake signal, a shift position signal, etc. are input as electrical signals, and the first to third solenoid valves 121 to 123 are turned on or off depending on the driving condition. Note that the first solenoid valve 121 is simply ON.
In addition to the case where OFF control is performed, so-called duty control may be performed in which the ratio of ON time and OFF time is changed within a constant cycle signal to generate an average oil pressure.

In the above hydraulic control system, when belt drive, adjusting the line pressure to correspond to the throttle opening allows for faster speed change control, and because there is no need for speed change control when direct drive is used, the line can be lower than when belt drive. It is preferable to use pressure because it can reduce the discharge loss of the oil pump. Furthermore, during coastdown, it is necessary to quickly shift the pulley ratio to the low speed ratio side, so it is necessary to generate a higher line pressure than during normal speed change control of belt drive. From this point of view, in the present invention, a signal hydraulic pressure when directly connected, a signal hydraulic pressure according to the throttle opening, and a signal hydraulic pressure during sudden deceleration (during 21-stroke down) are applied to the regulator valve 50, and multiple line pressures are controlled. The pressure was regulated in stages.

Here, to explain the pressure regulating operation by the regulator valve 50 in detail, during direct drive, the second solenoid valve 122 is OFF and the third solenoid valve 123 is ON, so the signal of baud 1-57.59 of the regulator valve 50 is The oil pressures P, , P, are turned OFF, and the line pressure is regulated to a low line pressure only by the signal oil pressure P2 acting on the boat 58 according to the throttle opening. For example, throttle valve 8
The throttle opening when the boat 86 of 0 is opened is 25
%, if the throttle opening is less than 25%, the boat will be 5.
8 signal oil pressure P2 is also turned OFF, and the line pressure is the lowest oil pressure balanced with the spring pressure (for example, 1.5 kg/c).
j), and when the throttle opening is 25% or more, the signal oil pressure P2 of the boat 58 is turned on, and the line pressure is a low oil pressure (for example, 1.8 kg/cd) that is balanced with the sum of the spring pressure and the signal oil pressure P2. The pressure is regulated to

Also, during normal belt drive, the second solenoid valve 1
22 and the third solenoid valve 123 are both OFF, the signal oil pressure P3 acting on the boat 59 of the regulator valve 50 is OFF, and the signal oil pressure P2 acting on the boat 58 and the boat 57 according to the throttle opening are turned OFF.
The line pressure is regulated to a desired line pressure by the signal hydraulic pressure P1 during non-direct connection that acts on the line pressure. For example, when the throttle opening is 25% or less, the signal hydraulic pressure P2 of the boat 58 is turned OFF, the signal hydraulic pressure P of the boat 57 is turned ON, and the line pressure is set to a hydraulic pressure balanced with the spring pressure and the signal hydraulic pressure P1 (for example, 3.0 kg/
cJ), and when the throttle opening is 25% or more, the signal oil pressure P2 of the boat 58 is also turned on, and the line pressure is set to a high oil pressure ( For example, the pressure is regulated to 5.0 kg/cIa).

Furthermore, during sudden deceleration, the second solenoid valve 122 is ON, the third solenoid valve 123 is 0FFL, and the throttle opening is fully closed, so that the signal hydraulic pressure P3 acting on the boat 59 of the regulator valve 50 and the boat 57 The signal oil pressure P1 is both turned ON, and the signal oil pressure P2 of the boat 58 is turned OFF. Therefore, the line pressure is regulated to the highest oil pressure (for example, 8.8 kg/c++) that is in balance with the spring pressure and the signal oil pressure P, P3, and rapid coast down control can be realized.

Table 1 summarizes the above operations. In this embodiment, the line pressure during direct drive is regulated in two steps, but it may be adjusted in one step since there is no need to change the line pressure during direct drive.

Table 10...Hydraulic pressure ON The pressure is regulated low, and when coasting down, the signal hydraulic pressure during sudden deceleration is used to generate a higher line pressure than during normal shift control, reducing oil pump discharge loss during direct drive and improving fuel efficiency. In addition to achieving this, it is also possible to achieve agile coastdown control.

[Brief explanation of the drawing]

FIG. 1 is a skeleton diagram of an example of a transmission according to the present invention;
FIG. 2 is a shift diagram, and FIG. 3 is a circuit diagram of the hydraulic control device. 6...Input shaft, 7...Direct connection gear, 8...Dong Craft, 10...■Belt type continuously variable transmission section, 20...
- Hydraulic clutch, 28... Counter gear (direct connection gear), 30... Differential device, 31... Output shaft, 50... Legipulator valve, 60... Pulley control valve, 70...・Course 1 - Down control valve, 80... Throttle valve, 90... Clutch control valve, 100... Lock-up control valve, 1
10... Actuator, 120... Control circuit, 1
21-123... Solenoid valve, P + ,
P2, Pl...Signal oil pressure. Applicant Daihatsu Motor Co., Ltd. Agent Patent Attorney Hidetaka Tsutsui Procedural Amendment Written December 18, 1985

Claims (1)

[Claims] (1) A direct drive path including a direct gear train and a belt drive path including a V-belt continuously variable transmission are provided in parallel between the input shaft and the output shaft, and the direct drive path and belt drive path are connected in parallel. In a transmission provided with a switching mechanism for selectively switching, a hydraulic chamber for controlling a pulley ratio provided in one of a driving pulley or a driven pulley of the V-belt type continuously variable transmission section;
A control valve that controls hydraulic pressure to the hydraulic chamber, and a regulator valve that supplies line pressure to the control valve,
A hydraulic control device for a transmission, wherein the regulator valve regulates line pressure in a plurality of stages using a signal hydraulic pressure when directly connected, a signal hydraulic pressure according to a throttle opening degree, and a signal hydraulic pressure during sudden deceleration.