JP3930924B2 - Control device for continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a continuously variable transmission that reduces a switching shock at the time of switching between forward and reverse in a belt type continuously variable transmission for a vehicle.
[0002]
[Prior art]
As a continuously variable transmission for a vehicle, a metal drive belt is mounted between a primary pulley provided on an input shaft and a secondary pulley provided on an output shaft, and the pulley diameter is changed by hydraulic pressure to change the output shaft. There is something that changes the number of revolutions in a stepless manner.
[0003]
A hydraulic multi-plate forward clutch and reverse brake are incorporated in the continuously variable transmission to switch the vehicle between forward and reverse movements. When the clutch is operated, the vehicle is in the forward mode, and when the reverse brake is operated, the vehicle is in the reverse mode. These clutches and brakes are operated by switching and supplying hydraulic pressure from a hydraulic pump driven by the engine to the clutch cylinder and the brake cylinder, respectively. For example, there is one described in JP-A-3-223565.
[0004]
[Problems to be solved by the invention]
When the hydraulic valve is switched by the operation of the select lever and the supply of hydraulic pressure to the clutch cylinder and the brake cylinder is switched, a switching shock occurs. To reduce this, an accumulator should be connected to the hydraulic circuit. ing.
[0005]
In a continuously variable transmission of a type in which the reverse brake is constituted by a double pinion planetary gear, that is, a planetary gear, the reverse brake is arranged on the primary pulley side, and the forward clutch is arranged on the torque converter side. In order to shorten the overall length of the transmission, it is necessary to dispose the brake cylinder outside the bearing that supports the shaft of the primary pulley. For this reason, since the brake cylinder cannot take an effective area larger than that of the clutch cylinder, the operating force of the brake cylinder may be a type in which the reverse brake has a planetary gear and needs to be set large. .
[0006]
As described above, since the brake cylinder must be supplied with a higher operating pressure than the clutch cylinder, it is necessary to supply hydraulic pressures having different pressures to the brake cylinder and the clutch cylinder. Therefore, in order to reduce the shock at the time of switching, conventionally, two accumulators for the brake cylinder and the clutch cylinder are provided.
[0007]
However, when two accumulators are incorporated, not only the hydraulic circuit in the transmission is complicated, but also the installation space is required.
[0008]
An object of the present invention is to make it possible to reduce a switching shock at the time of switching between forward and reverse in a continuously variable transmission with a simple structure.
[0009]
[Means for Solving the Problems]
Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
[0010]
That is, the control device for a continuously variable transmission according to the present invention includes a pulley having a variable pulley interval attached to an input shaft, and a pulley interval attached to an output shaft and a drive belt being spanned between the primary pulleys. Operates a variable secondary pulley, a clutch cylinder that operates a forward clutch that transmits engine-side rotation to the input shaft in the forward direction, and a reverse brake that transmits engine-side rotation to the input shaft in the reverse direction. And a control device for a continuously variable transmission having a brake cylinder having an oil chamber area smaller than that of the clutch cylinder, wherein hydraulic pressure from a hydraulic source driven by the engine is controlled to a predetermined pressure and supplied. When the first and second inflow ports are connected to the brake cylinder via a brake oil passage and set to the reverse position The first discharge port that is in conduction with the first inflow port, and is connected to the second inflow port when connected to the clutch cylinder via a clutch oil passage and set in the forward position. A manual valve having a second discharge port; and the manual valve But In the retracted position When set, the conduction with the first and second inflow ports is interrupted, while when the manual valve is set to the forward position, the first and second inflow ports are in conduction. By hydraulic pressure from pressure adjustment port The hydraulic pressure supplied to the first discharge port via the first inflow port when the manual valve is set to the retracted position, and the hydraulic pressure supplied to the first discharge port when the manual valve is set to the forward position. Said second discharge port via a second inflow port A pressure control valve that sets a pressure higher than the hydraulic pressure supplied to the manual valve, and the manual valve Is set to the retracted position, the accumulator chamber communicates with the first discharge port, and when the manual valve is set to the advanced position, an accumulator oil passage is connected to the second discharge port. And an accumulator provided with a support chamber connected to a support oil passage to which assist pressure is supplied. When the manual valve is set at the retracted position, the accumulator is supplied to the brake cylinder and the accumulator chamber. The hydraulic pressure is higher than the hydraulic pressure supplied to the clutch cylinder and the accumulator chamber when the manual valve is set to the forward position. It is characterized by that.
[0011]
In the control device for a continuously variable transmission having such a configuration, when the pressure control valve is operated by the pressure adjusting port provided in the manual valve and the manual valve is operated to the forward position, the clutch cylinder and The pressure conducted to the accumulator and the pressure conducted to the brake cylinder and the accumulator when the manual valve is operated to the reverse position are set to different pressures. The common accumulator can reduce the switching shock at the time of forward / reverse switching, thereby reducing the number of parts and reducing the size of the apparatus.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0013]
FIG. 1 is a skeleton diagram showing a drive system of a continuously variable transmission for a vehicle using a belt. A crankshaft 1 driven by an engine (not shown) has a drive plate 4 attached to a pump side case 3 of a torque converter 2. The turbine runner 5 disposed so as to face the pump impeller 3 a provided in the pump side case 3 is directly connected to the turbine shaft 6. A stator 7 is disposed between the pump impeller 3 a and the turbine runner 5 and supported by a one-way clutch 8. As a result, engine power is transmitted to the turbine shaft 6 via the torque converter 2.
[0014]
The turbine shaft 6 is transmitted to the input shaft 13 of the continuously variable transmission 12 via the forward / reverse switching mechanism 11. A primary pulley 14 is provided on the input shaft 13, and a primary movable sheep 14 a is attached to the input shaft 13 so as to be slidable in the axial direction with respect to the input shaft 13 by a ball spline or the like. The pulley interval is variable. A secondary pulley 16 is provided on the output shaft 15 arranged in parallel with the input shaft 13, and the movable sheave 16 a on the secondary side is opposed to the output shaft 15 in the axial direction in the same manner as the movable sheep 14 a. The secondary pulley 16 has a variable pulley interval. The entire drive system is incorporated in the case 10.
[0015]
A drive belt 17 is stretched between the primary pulley 14 and the secondary pulley 16. By changing the groove width of both the pulleys 14, 16, the ratio of the winding diameter to the pulleys 14, 16 can be changed. By changing the speed, the rotational speed of the output shaft 15 is continuously variable.
[0016]
In order to change the groove width of the primary pulley 14, a cylinder 19 that forms an oil chamber 18 with the movable sheep 14 a is attached to the input shaft 13, and in order to change the groove width of the secondary pulley 16, the movable sheep 16 a A cylinder 22 that forms an oil chamber 21 is attached to the output shaft 15.
[0017]
The output shaft 15 is connected to the intermediate shaft 25 via gears 23, 24, and the gear 26 attached to the intermediate shaft 25 meshes with the final gear 28 of the differential device 27, and the axle 29 a, connected to the differential device 27, Wheels 31a and 31b are attached to 29b. In the case of a front wheel drive vehicle, the wheels 31a and 31b are front wheels.
[0018]
The forward / reverse switching mechanism 11 includes an annular clutch cylinder 32 having a forward clutch drum portion fixed to the turbine shaft 6, and a carrier 34 fixed to the input shaft 13 and having a clutch hub at an end thereof. A multi-plate forward clutch 36 is provided between the clutch drum portion provided at the end of the cylinder 32 and the clutch hub 35, and a hydraulic piston 37 for operating the forward clutch 36. Is incorporated in the clutch cylinder 32. Therefore, when the hydraulic pressure is supplied to the oil chamber 32a in the clutch cylinder 32 and the forward clutch 36 is in the connected state, the rotation of the turbine shaft 6 is transmitted to the input shaft 13 via the clutch hub 35 and the carrier 34 and input shaft. 13 rotates in the same normal rotation direction as the turbine shaft 6.
[0019]
The planetary pinion gears 38 and 39 that mesh with each other and are paired with each other are rotatably mounted on the support shaft fixed to the carrier 34. One planetary pinion gear 38 meshes with a sun gear 41 fixed to the turbine shaft 6, and the other. The planetary pinion gear 39 meshes with the internal teeth of a ring gear 42 provided outside the sun gear 41, and a double pinion planetary gear is constituted by these gears. In FIG. 1, the planetary pinion gears 38 and 39 are shown apart from each other for convenience of drawing, but they are meshed with each other as a pair, and a plurality of these planetary pinion gears 38 and 39 may be provided. good. A multi-plate type reverse brake 43 is provided between the ring gear 42 and the case 10, and a hydraulic piston 44 for operating the reverse brake 43 is incorporated in a brake cylinder 45 formed in the case 10. It is.
[0020]
Therefore, when the forward clutch 36 is released and the hydraulic pressure is supplied to the oil chamber 45a in the brake cylinder 45 to bring the reverse brake 43 into a braking state, the ring gear 42 is fixed to the case 10. Therefore, the rotation of the sun gear 41 integrated with the turbine shaft 6 is transmitted to the carrier 34 via the paired planetary pinion gears 38 and 39, and the input shaft 13 rotates in the reverse rotation direction opposite to that of the turbine shaft 6.
[0021]
Thus, the reverse brake 43 is disposed on the primary pulley 14 side, and the forward clutch 36 is disposed on the torque converter 2 side, and the bearing that supports the shaft of the primary pulley 14 in order to shorten the overall length of the transmission. A brake cylinder 45 is disposed outside 46. For this reason, since the brake cylinder 45 cannot take an effective area larger than that of the clutch cylinder 32, the operating pressure in the oil chamber 45a in the brake cylinder 45 is higher than that in the oil chamber 32a in the clutch cylinder 32. It is necessary to supply hydraulic pressure.
[0022]
In order to operate hydraulically operated devices such as the brake cylinder 45 and the clutch cylinder 32, an oil pump 47 as a hydraulic pressure source is disposed in the case 10. The oil pump 47 is connected to the pump side case 3 by the crankshaft 1. It is to be driven through.
[0023]
FIG. 2 is a diagram showing a hydraulic circuit for controlling the operation of the drive system shown in FIG. 1, and the oil pump 47 is a trochoidal gear pump that meshes with a drive side gear driven by an engine. It has a driven gear and is provided with a discharge port 48 and a suction port 49. An inflow side oil passage 52 connected to the oil pan 51 is connected to the suction port 49, and a line pressure oil passage 53 is connected to the discharge port 48.
[0024]
The line pressure oil passage 53 is connected to the oil chamber 21 that operates the movable sheep 16 a on the secondary pulley 16 side, and is connected to the line pressure ports of the transmission control valve 54 and the line pressure control valve 55. These control valves 54 and 55 are proportional electromagnetic relief valves, each having a solenoid that is operated by electric power from the control unit 56.
[0025]
The line pressure control valve 55 controls the line pressure supplied to the oil chamber 21 of the secondary pulley 16, that is, the secondary pressure, by controlling the pressure of the line pressure oil passage 53 corresponding to the current supplied from the control unit 56 to the solenoid. . A control pressure oil passage 57 is connected to the discharge port of the line pressure control valve 55, and the control pressure oil passage 57 supplies a control pressure having a predetermined pressure.
[0026]
The primary port of the speed change control valve 54 is connected to a primary oil passage 58 communicating with the oil chamber 18 for operating the movable sheep 14a on the primary pulley 14 side. The speed change control valve 54 is supplied to the solenoid from the control unit 56. The primary pressure corresponding to the current is supplied to the oil chamber 18. Since this primary pressure is set by adjusting the line pressure, it does not exceed the line pressure. However, since the cross-sectional area of the oil chamber 18 is set to be larger than the cross-sectional area of the oil chamber 21, the force for clamping the drive belt 17 can be made larger than that on the secondary pulley side.
[0027]
When the engine output, such as climbing or sudden acceleration, is large, the line pressure is regulated high to prevent the drive belt 17 from slipping. When the engine output is small, the line pressure is regulated low to reduce the oil pump 47 loss and transmission efficiency. Is improved.
[0028]
As described above, when the vehicle is advanced, hydraulic pressure is supplied to the oil chamber 32a in the clutch cylinder 32 of the forward clutch 36, and when the vehicle is moved backward, the oil chamber in the brake cylinder 45 of the reverse brake 43 is supplied. The hydraulic pressure is supplied to 45a, and the supply of hydraulic pressure to the oil chambers 32a and 45a is stopped otherwise.
[0029]
In order to operate the forward clutch 36 and the reverse brake 43 in this way, a manual valve 61 that is operated by a control lever, that is, a select lever provided in the vehicle interior is provided. The manual valve 61 has a valve case 62 and a spool valve body 63 that slides in the valve case 62. The valve case 62 is formed with a first inflow port 62a and a second inflow port 62b. A control pressure oil passage 57 is connected to the ports 62a and 62b.
[0030]
An enlarged view of the manual valve 61 is as shown in FIGS. 3A to 3C and FIGS. 4A and 4B. A brake oil passage 64 communicating with the oil chamber 45a is connected to the brake cylinder 45 of the reverse brake 43, and the brake oil passage 64 is connected to a first discharge port 62c formed in the valve case 62. When the manual valve 61 is set to the retracted position as shown in FIG. 4A, the first inflow port 62a and the first discharge port 62c are brought into conduction, and the hydraulic pressure from the control pressure oil passage 57 is increased. It is supplied into the brake cylinder 45.
[0031]
A clutch oil passage 65 communicating with the oil chamber 32 a is connected to the clutch cylinder 32 of the forward clutch 36, and this clutch oil passage 65 is connected to a second discharge port 62 d formed in the valve case 62. When the manual valve 61 is set to the forward position as shown in FIGS. 3 (A) and 3 (B), the second inflow port 62b and the second discharge port 62d become conductive, and the control pressure oil The hydraulic pressure from the passage 57 is supplied into the clutch cylinder 32. 3A shows the DS range, and FIG. 3B shows the D range. Even in the DL range, the continuity of the DS range and each port is the same.
[0032]
A third inflow port 62e is formed in the valve case 62. Further, the inflow port 62e is formed when the manual valve 61 is set at the forward position as shown in FIGS. 3 (A) and 3 (B). A pressure regulating port 62f that is in a conductive state is formed.
[0033]
As shown in FIG. 2, the control pressure oil passage 57 is connected to a pressure control port 66a of the pressure control valve 66. The pressure control valve 66 includes a spring member and a spool valve body. A pressure regulating port 66b connected to the pressure regulating port 62f by a pilot oil passage 67 and a lubricating oil discharge port 66c are formed in the pressure control valve 66. When the hydraulic pressure is supplied to the pressure adjusting port 66b, the opening degree between the pressure control port 66a and the lubricating oil discharge port 66c changes. Therefore, when the manual valve 61 is set to the forward position, as shown in FIGS. Oil passage Since the hydraulic pressure is supplied to the pressure adjusting port 66b via 67 and the opening degree of the lubricating oil discharge port 66c is increased, the pressure of the oil supplied to the second inflow port 62a formed in the manual valve 61, that is, control. The pressure is controlled to a low value.
[0034]
When the manual valve 61 is set to a position other than the forward movement position such as the R range, the conduction between the pressure adjustment port 62f and the third inflow port 62e is cut off, so that the pressure higher than that when the manual valve 61 is set to the forward movement position. The control pressure is supplied to the first and second inflow ports 62a and 62b. Thus, the pressure control valve 66 is actuated to the low pressure side by the hydraulic pressure from the pressure regulating port 62 f formed in the manual valve 61, and a control pressure having a lower pressure than that in the brake cylinder 45 is supplied into the clutch cylinder 32. The
[0035]
As shown in the figure, as the pressure control valve 66, when the manual valve 61 is set to the forward position, the control pressure is lowered and supplied to the clutch cylinder 32 as compared with the other position. However, when the hydraulic pressure from the pilot oil passage 67 is set to a position other than the forward movement position, oil having a higher pressure than that when the forward movement position is set is supplied to the inflow ports 62a and 62b and supplied to the brake cylinder 45. You may make it supply in. That is, any pressure may be used as long as the pressure supplied into the brake cylinder 45 can be set higher than the pressure supplied into the clutch cylinder 32.
[0036]
The lubricating oil discharge port 66 c of the pressure control valve 66 is connected to the inflow port of the torque converter 2 by an inflow oil passage 68, and the discharge port of the torque converter 2 is connected to the oil pan 51 by an outflow oil passage 69. As a result, the lubricating oil is circulated in the torque converter 2, and a lubricating pressure control valve 71 is connected to the inflowing oil path 68 in order to adjust the pressure of the lubricating oil in the inflowing oil path 68. An oil cooler 72 is provided in the outflow oil passage 69.
[0037]
As shown in FIG. 2, an accumulator oil passage 74 is connected to a third discharge port 62g formed in the manual valve 61, and this accumulator oil passage 74 is connected to an accumulator chamber 76 of an accumulator 75. A support chamber 78 is partitioned from the accumulator chamber 76 by a piston 77 incorporated in the 75. The support chamber 78 applies a force for operating the accumulator chamber 76 in a contracting direction, and a spring for applying a spring force in a direction for contracting the accumulator chamber 76 to the piston 77 in the accumulator 75. A member 79 is incorporated.
[0038]
As shown in FIG. 4A, the accumulator oil passage 74 becomes conductive to the inflow port 62a via the discharge ports 62c and 62g when the manual valve 61 is set to the R range. At this time, the inflow port 62e And pressure regulating port 62f Therefore, the control pressure from the control pressure oil passage 57 is supplied into the accumulator chamber 76 as it is. Further, at this time, since the discharge ports 62 d and 62 c are in a conductive state, the control pressure is supplied to the brake cylinder 45 via the brake oil passage 64.
[0039]
Further, as shown in FIGS. 3A and 3B, when the manual valve 61 is set to the D range and the DL to DS range, the inflow port 62b and the discharge ports 62d and 62g are in a conductive state. Since the inflow port 62e and the pressure adjusting port 62f are in a conductive state, the control pressure that is lower than that when the pressure control valve 66 is not operated is supplied into the clutch cylinder 32 by the operation of the pressure control valve 66. Further, at this time, the control pressure is supplied to the accumulator chamber 76 via the accumulator oil passage 74.
[0040]
A support oil passage 81 connected to the line pressure oil passage 53 is connected to the support chamber 78, and assist pressure is supplied to the support chamber 78.
[0041]
FIG. 5 is a characteristic diagram showing the operating characteristics of the accumulator 75. As shown in this figure, the control pressure range PB of the brake cylinder 45 of the reverse brake 43 and the control pressure range PC of the clutch cylinder 32 of the forward clutch 36 are different from each other. Operates within the high pressure range.
[0042]
When the manual valve 61 is set to the R range, that is, the reverse position, the control pressure is supplied to the brake cylinder 45 and the accumulator chamber 76, so that the pressure therein increases with time and reaches the line pressure P1. . Similarly, when the manual valve 61 is set to the D, DL, DS range, that is, the forward position, the control pressure controlled to be lower than that when the manual valve 61 is set to the reverse position is supplied to the clutch cylinder 32 and the accumulator chamber 76. These pressures increase with time and reach the lubricating pressure P2.
[0043]
A constant spring force is applied to the accumulator chamber 76 via the piston 77 by the spring member 79 incorporated in the accumulator 75, and line pressure is supplied to the support chamber 78 from the line pressure oil passage 53, thereby assisting pressure. Thus, the stroke characteristic (stroke characteristic during brake operation) SB of the piston 77 in the accumulator 75 when the line pressure is supplied to the reverse brake 43 is as shown in the figure. Further, the stroke characteristic (stroke characteristic during clutch operation) SC of the piston 77 in the accumulator 75 when the control pressure is supplied to the forward clutch 36 is as shown in the figure.
[0044]
As described above, the line pressure supplied to the support chamber 78 corresponding to the pressure supplied to the accumulator chamber 76 is used as the assist pressure. By controlling the line pressure, the brake cylinder 45 and the accumulator chamber 76 are controlled. When the hydraulic pressure is supplied, the line pressure controlled to a higher pressure is supplied as the assist pressure to the support chamber 78 than when the hydraulic pressure is supplied to the clutch cylinder 32 and the accumulator chamber 76. Shelf pressure will be applied. As a result, the accumulator 75 is pressure-adjusted both when moving forward and when moving backward, so that the inclination angles of the respective characteristics SB and SC become the same, and the predetermined stroke is operated in substantially the same time. By using the common accumulator 75, the switching shock during forward switching and reverse switching can be reduced with the same characteristics.
[0045]
The operating times of the forward clutch 36 and the reverse brake 43 are controlled by throttles or orifices 82 and 83 provided on the upstream side of the inflow ports 62a and 62b in the control pressure oil passage 57, respectively.
[0046]
When the hydraulic pressure is made conductive in the clutch cylinder 32 and the hydraulic pressure is made conductive in the brake cylinder 45 by the operation of the manual valve 61, the accumulator oil passage 74 is made conductive before the respective conduction is made. Hydraulic pressure may be supplied into the chamber 76, and such a configuration is achieved by optimizing the switching timing by setting the spool shape of the manual valve and the port position provided in the valve.
[0047]
The manual valve 61 has an irregular communication groove in which the spool valve body 63 is asymmetrical about the central axis thereof, and the inflow port 62a and the discharge port 62c are in a conductive state at the position of the R range, and are in a conductive state in other ranges. Is solved. Further, the inflow port 62b and the discharge port 62d are brought into conduction through the discharge port 62g at the positions of the DS, DL, and D ranges, and the conduction is released in the other ranges. The discharge ports adjacent in the axial direction are electrically connected to each other according to the operation position of the manual valve 61.
[0048]
As shown in FIGS. 3C, 4A, and 4B, the valve case 62 is set to the N, R, and P ranges when the manual valve 61 is set to a position other than the forward position. In this case, a drain port 62h that is conducted to the clutch oil passage 65 and a drain port 62i that is conducted to the pilot oil passage 67 are formed. At this time, the hydraulic pressure in the clutch cylinder 32 and the pilot oil passage 67 Is discharged to the oil pan 51. In addition, the valve case 62 is formed with a drain port 62j that is connected to the discharge port 62c and discharges the hydraulic pressure in the brake cylinder 45 when the manual valve 61 is set to a position other than the reverse position.
[0049]
As described above, when the hydraulic pressure in the brake cylinder 45 is discharged and when the hydraulic pressure in the clutch cylinder 32 is discharged, the brake oil passage 64 and the clutch oil passage 65 are connected under the state where the accumulator oil passage 74 is conducted. The hydraulic pressure in each of the cylinders 45 and 32 may be discharged after closing. Such an operation is achieved by optimizing the switching timing by setting the spool shape of the manual valve and the port position provided in the valve.
[0050]
Next, the operation of the continuously variable transmission when the vehicle is moved forward and backward by operating the control lever will be described.
[0051]
In a state where the vehicle is parked, the select lever is set to the P range, and as shown in FIG. 4B, the spool valve body 63 of the manual valve 61 is set to the rightmost position in the figure. Sometimes, even if the engine is operating, the inflow ports 62a, 62b, 62e connected to the control pressure oil passage 57 are not connected to any discharge port, so the brake cylinder 45 of the reverse brake 43 and the forward The hydraulic pressure is not supplied to the clutch cylinder 32 of the clutch 36, and the reverse brake 43 and the forward clutch 36 are off.
[0052]
When the manual valve 61 is set to the R range to reverse the vehicle in this state, the first inflow side port 62a is electrically connected to the brake oil passage 64 and the accumulator oil passage 74 as shown in FIG. The hydraulic pressure is supplied to the oil chamber 45 a and the accumulator chamber 76 in the brake cylinder 45. As a result, the reverse brake 43 is turned on, and the input shaft 13 rotates in the reverse direction. At this time, since the line pressure is supplied not only in the brake cylinder 45 but also in the accumulator chamber 76, the switching shock at the time of switching from the P range to the R range is reduced. While the R range is maintained, the brake fluid passage 64 and the accumulator fluid passage 74 are always kept in conduction with the control pressure fluid passage 57.
[0053]
When the manual valve 61 is operated from the R range to the neutral N range, the reverse brake 43 is turned off and the hydraulic pressure in the oil chamber 45a of the brake cylinder 45 is drained as shown in FIG. The hydraulic pressure in the accumulator chamber 76 from the port 62j is discharged from the drain port 62h and returned to the oil pan 51.
[0054]
When the manual valve 61 is operated from the N range to the D range by operating the control lever, the second inflow port 62b is connected to the clutch oil passage 65 and the accumulator oil passage 74, respectively, as shown in FIG. Since the inflow port 62e is in a conduction state with the pressure adjusting port 62f, the cotton roll pressure whose pressure is lower than the hydraulic pressure supplied into the brake cylinder 45 is applied to the oil chamber 32a in the clutch cylinder 32. In addition to being supplied, it is also supplied into the accumulator chamber 76. As a result, the forward clutch 36 is turned on, and the input shaft 13 rotates in the forward direction. At this time, since the hydraulic pressure is supplied not only to the clutch cylinder 32 but also to the accumulator chamber 76, the switching shock at the time of switching from the N range to the D range is reduced. While the D range is held, the clutch oil passage 65 and the accumulator oil passage 74 are always held in conduction with the control pressure oil passage 57.
[0055]
Even when the manual valve 61 is operated in the DS range and the DL range, the conduction state of the D range is maintained. When the manual valve 61 is operated from the D range to the neutral N range, the hydraulic pressure in the oil chamber 32a and the accumulator chamber 76 of the clutch cylinder 32 is discharged from the drain ports 62h and 62j and returned to the oil pan 51, respectively. It is.
[0056]
The operating speeds of the reverse brake 43 and the forward clutch 36 are controlled by orifices 82 and 83 provided on the upstream side of the inflow ports 62 a and 62 b in the control pressure oil passage 57.
[0057]
Further, by providing orifices in the brake oil passage 64 and the clutch oil passage 65, the hydraulic pressure can be supplied to the accumulator chamber 76 in the accumulator 75 before the hydraulic pressure acts on the brake cylinder 45 and the clutch cylinder 32. As a result, the switching shock can be further reduced.
[0058]
Further, when the supply of hydraulic pressure to the brake cylinder 45 and the clutch cylinder 32 is stopped, the brake oil passage 64 and the clutch oil passage 65 are closed in a state where the accumulator oil passage 74 is in a conductive state, and then the respective cylinders are closed. The hydraulic pressure in 45 and 32 is discharged from the drain ports 62h and 62j.
[0059]
FIG. 6 is a circuit diagram showing a hydraulic system in a control device for a continuously variable transmission according to another embodiment of the present invention, and members common to those shown in FIG. Yes.
[0060]
This hydraulic circuit has a shift control valve 84 that performs the same function as the shift control valve 54 shown in FIG. 2 and a line pressure adjustment valve 85 that performs the same function as the line pressure control valve 55. In this case, the support oil passage 81 is connected to the control pressure oil passage 57 while the support oil passage 81 is connected to the line pressure oil passage 53 in the case shown in FIG.
[0061]
The line pressure adjusting valve 85 controls the hydraulic pressure supplied to the oil chamber 21 of the secondary pulley 16 and supplies the hydraulic pressure to the control pressure oil passage 57, and the spring force of the spring member moves the primary pulley 14. Adjustment is made by a ratio sensor 86 connected to the sheep 14a. The line pressure adjusting valve 85 is formed with a port 85a to which the line pressure oil passage 53 is connected and a port 85b to which the control pressure oil passage 57 is connected, and the oil pressure generated by the rotation of the primary pulley 14 is supplied. A pitot pressure oil passage 87 is connected to the side facing the spring force. Therefore, when the pulley ratio is large on the low side, the spring force is increased and the line pressure is increased, and when the pulley ratio is small, the line pressure is decreased. Further, the line pressure adjustment valve 85 operates so that the line pressure is lowered when the engine speed is high and the Pitot pressure is high, and the increase in the line pressure is suppressed when the engine speed is low.
[0062]
The shift control valve 84 controls the primary pressure supplied to the oil chamber 18 of the primary pulley 14 by adjusting the line pressure, and the relationship between the pitot pressure of the pitot pressure oil passage 87 and the depression amount of the accelerator pedal. Thus, the gear ratio is controlled. That is, when the accelerator pedal is depressed, due to the action of the shift cam 84a in conjunction with the accelerator pedal, when the accelerator pedal is deeply depressed, the operation is performed in the direction of discharging the primary pressure in the oil chamber 18, and the gear is shifted to the low side. When the engine speed increases and the Pitot pressure increases, the engine operates in a direction to supply the line pressure to the oil chamber 18, and shift control is performed to the high side as the primary pressure increases.
[0063]
Here, the hydraulic pressure discharged from the oil pump 47 is regulated to a predetermined line pressure according to the gear ratio and the like while flowing out to the port 85 b side by the line pressure adjusting valve 85. port 85b The hydraulic pressure flowing out from the oil passage 57 is supplied to the oil passage 57 and is adjusted to a control pressure by a pressure control valve 66 provided in the oil passage. Based on this control pressure, similarly to the embodiment of FIG. 2, the switching operation of the forward / reverse switching mechanism 11 and the switching shock at the time of switching by the accumulator 75 are reduced.
[0064]
As described above, the present invention is applied to a continuously variable transmission of the type in which the primary pressure and the line pressure are controlled by the transmission control valve 54 and the line pressure control valve 55, which are proportional electromagnetic relief valves, respectively, according to the signal from the control unit. In addition, it can be applied to a type in which the primary pressure and the line pressure are mechanically controlled in accordance with the engine speed, the amount of depression of the accelerator pedal, and the like.
[0065]
As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.
[0066]
【The invention's effect】
Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.
[0067]
(1) A common accumulator can reduce switching shock when switching between forward and reverse in a continuously variable transmission.
[0068]
(2) Since the switching shock can be reduced by using a single common accumulator, the structure becomes simpler than when the forward accumulator and the backward accumulator are used.
[Brief description of the drawings]
FIG. 1 is a skeleton diagram showing a drive system of a continuously variable transmission control apparatus according to an embodiment of the present invention.
FIG. 2 is a hydraulic circuit diagram showing a hydraulic system that controls the operation of the control device shown in FIG. 1;
3A to 3C are enlarged cross-sectional views showing the operating state of the manual valve shown in FIG. 2, respectively.
4A and 4B are enlarged cross-sectional views showing the operating state of the manual valve shown in FIG. 2, respectively.
FIG. 5 is a diagram showing operating characteristics of the accumulator shown in FIG. 2;
FIG. 6 is a hydraulic circuit diagram showing a hydraulic system for controlling the operation of the control device according to another embodiment of the present invention.
[Explanation of symbols]
1 Crankshaft
2 Torque converter
3 Pump side case
5 Turbine runner
6 Turbine shaft
7 Stator
10 cases
11 Forward / reverse switching mechanism
12 continuously variable transmission
13 Input shaft
14 Primary pulley
15 Output shaft
16 Secondary pulley
17 Drive belt
18 Oil chamber
19 cylinders
21 Oil chamber
22 cylinders
27 Differential equipment
32 Clutch cylinder
34 Career
35 Clutch hub
36 Forward clutch
37 Hydraulic piston
38,39 Planetary pinion gear
43 Reverse brake
47 Oil pump
53 Line pressure oil passage
54 Shift control valve
55 Line pressure control valve
56 Control unit
57 Control pressure oil passage
58 Primary oil passage
61 Manual valve
64 Brake oil passage
65 Clutch oil passage
66 Pressure control valve
67 Pilot oil passage
71 Lubrication pressure control valve
74 Accumulator oil passage
75 Accumulator
76 Accumulator room
77 piston
78 Support room
79 Spring member
81 Support oil passage
82,83 Orifice
84 Shift control valve
85 Line pressure regulating valve
86 Ratio sensor
87 Pitot pressure oil passage

Claims (4)

A primary pulley with variable pulley spacing mounted on the input shaft, a secondary pulley with variable pulley spacing mounted on the output shaft and a drive belt spanned between the primary pulley, and rotation on the engine side on the input shaft A clutch cylinder that operates a forward clutch that transmits the rotation in the forward direction to the engine, and a brake cylinder that operates a reverse brake that transmits engine-side rotation in the reverse direction to the input shaft and has a smaller oil chamber area than the clutch cylinder A continuously variable transmission control device comprising:
The first and second inflow ports to which the hydraulic pressure from the hydraulic source driven by the engine is controlled and supplied to a predetermined pressure are connected to the brake cylinder via a brake oil passage and set to the reverse position. A first discharge port that becomes conductive when connected to the first inflow port, and is connected to the second inflow port when connected to the clutch cylinder via a clutch oil passage and set to a forward position. A manual valve having a second discharge port to be in a state;
When the manual valve is set to the retracted position, conduction with the first and second inflow ports is interrupted, while when the manual valve is set to the advanced position, the first and second inflows are set. The hydraulic pressure supplied to the first discharge port via the first inflow port when the manual valve is set to the retracted position by the hydraulic pressure from the pressure adjusting port that is in conduction with the port, A pressure control valve for setting a pressure higher than the hydraulic pressure supplied to the second discharge port via the second inflow port when the manual valve is set to the forward position ;
When the manual valve is set to the retracted position, it communicates with the first discharge port, while when the manual valve is set to the advanced position, an accumulator oil passage communicating with the second discharge port is connected. An accumulator provided with an accumulator chamber and a support chamber connected to a support oil passage to which assist pressure is supplied,
When the manual valve is set to the reverse position, the hydraulic pressure supplied to the brake cylinder and the accumulator chamber is supplied to the clutch cylinder and the accumulator chamber when the manual valve is set to the forward position. A control device for a continuously variable transmission, characterized by being higher than the hydraulic pressure applied . The control device for a continuously variable transmission according to claim 1, wherein the manual valve applies hydraulic pressure to the accumulator oil chamber before hydraulic pressure is applied to the brake cylinder and hydraulic pressure is applied to the clutch cylinder. supply to the control device of the continuously variable transmission, wherein Rukoto.   The control device for a continuously variable transmission according to claim 1, wherein the manual valve discharges hydraulic pressure in the accumulator chamber when discharging hydraulic pressure in the brake cylinder and discharging hydraulic pressure in the clutch cylinder. A control device for a continuously variable transmission, wherein   4. The control device for a continuously variable transmission according to claim 3, wherein the manual valve is configured such that when the hydraulic pressure in the brake cylinder and the clutch cylinder is discharged, the brake oil is in a state where the accumulator oil passage is conducted. A control device for a continuously variable transmission, characterized in that a road and a clutch oil path are closed and then the hydraulic pressure in each cylinder is discharged.

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