JP4652511B2 - Hydraulic control device for continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic control device for a belt type continuously variable transmission.
[0002]
[Prior art]
In a belt type continuously variable transmission (CVT) for automobiles, a pulley pulley having a variable pulley groove width provided on a drive-side primary shaft and a pulley groove width having a variable pulley groove width provided on a driven-side or driven-side secondary shaft are provided. There is a belt in which a metal belt is stretched between the secondary pulley and the diameter of the primary pulley and the secondary pulley is changed by hydraulic pressure so that the rotation speed of the secondary shaft is changed steplessly.
[0003]
The shift control of the CVT is performed by controlling the hydraulic pressure to the drive oil chambers of the hydraulic cylinders respectively provided on the primary side and the secondary side, and the hydraulic pressure applied to each drive oil chamber is driven by the engine. It is generated by the oil pump. The line pressure applied to the drive oil chamber of the secondary hydraulic cylinder, that is, the secondary pressure is adjusted by the secondary valve, and the primary pressure applied to the drive oil chamber of the primary hydraulic cylinder is adjusted by the primary valve using the line pressure as the original pressure. I am doing so.
[0004]
When the CVT is operating, the primary pulley and the secondary pulley are rotating at a certain gear ratio, the centrifugal oil pressure due to rotation acts on the drive oil chamber of each cylinder, and the centrifugal oil pressure is applied to each drive oil chamber with respect to the belt. This is the direction in which the pressing force is applied. As a result, the centrifugal hydraulic pressure applied to the drive oil chamber of the primary pulley structurally acts on the gear ratio in the high speed step direction, and the centrifugal hydraulic pressure applied to the drive oil chamber of the secondary pulley acts on the gear ratio in the low speed step direction. Become.
[0005]
Therefore, when the gear ratio is to be fixed at a low speed, a clamp load is applied to the drive oil chamber on the secondary pulley side so as not to be shifted by the centrifugal hydraulic pressure generated in the drive oil chamber on the primary pulley side. There must be. On the other hand, if the gear ratio is to be fixed at a high speed, a clamping load must be applied to the drive oil chamber on the primary pulley side so that the gear is not shifted by the centrifugal hydraulic pressure generated in the drive oil chamber on the secondary pulley side. Don't be. For this reason, it is necessary to generate an excessive belt clamping force with respect to the driving torque, and not only the friction loss of the belt but also the mechanical loss of the oil pump occurs.
[0006]
[Problems to be solved by the invention]
JP-A-62-257651 discloses a CVT in which, in addition to a drive oil chamber, a balance oil chamber for balancing centrifugal hydraulic pressure generated in the drive oil chamber is formed in a cylinder on the secondary pulley side. ing.
[0007]
In addition to the drive oil chamber, a balance oil chamber is formed not only on the secondary pulley side cylinder but also on the primary pulley side cylinder, and centrifugal oil pressure in the opposite direction to the centrifugal oil pressure generated by the drive oil chamber is generated in the balance oil chamber. However, conventionally, hydraulic oil is supplied to each balance oil chamber from a lubrication pressure path.
[0008]
By the way, in CVT, various devices are driven by using an oil pump driven by an engine as a hydraulic pressure source. In other words, not only the primary pulley and the secondary pulley but also the forward / backward switching mechanism provided in the forward / reverse switching mechanism is switched by hydraulic pressure. A clutch pressure obtained by reducing the line pressure by a pressure valve is supplied. The clutch pressure is also supplied to the lock-up apply chamber in the torque converter having the lock-up clutch, and the lock-up release chamber is supplied with the lubrication pressure adjusted to the drain pressure of the secondary valve. The lockup clutch is switched on and off by the lubricating pressure. The lubrication pressure is supplied to the lubrication part of the forward / reverse switching mechanism, the lubrication of the belt, the balance oil chamber and the like in addition to the lockup clutch.
[0009]
For this reason, in CVT, in order to ensure the speed of the pulley when the pulley shifts and to prevent the belt from slipping due to a decrease in the clamping force of the belt, the change in the volume of the drive oil chamber in the cylinder is prevented. In addition, it is necessary to set the capacity of the oil pump so that the flow rate of hydraulic oil necessary for forward / reverse switching control, lock-up control and lubrication of each part can be secured after securing a sufficient supply oil amount. is there.
[0010]
Therefore, the energy loss of the oil pump in CVT includes not only the sliding resistance of each part, but also the amount of oil supplied to the part that operates sufficiently at a pressure lower than the shift control pressure by the pulley. Including the pulley transmission control pressure, the oil pump pressurizes and supplies the oil, and this increases the energy required for the oil pump.
[0011]
Therefore, since it is necessary to maintain the hydraulic pressure in order to secure the belt clamping force to prevent belt slip, the line pressure is not required originally, and the required oil amount of the lubricating pressure that always requires the oil amount is increased. If the number is reduced, it is considered that the hydraulic energy loss in the hydraulic control device of the CVT can be reduced, and the driving energy of the oil pump can be reduced. For example, when a speed change operation using a pulley is performed, hydraulic oil with a line pressure is required. At this time, a switching operation is performed in an oil passage that supplies hydraulic pressure to a forward clutch and a reverse brake that are supplied with clutch pressure. Since it is not performed, almost no oil amount is required, and in order to reduce the required oil amount, the oil amount of the lubricating pressure may be reduced.
[0012]
An object of the present invention is to reduce the consumption of hydraulic oil at a lubricating pressure and to reduce the amount of oil discharged from an oil pump.
[0013]
Another object of the present invention is to reduce the mechanical loss of the oil pump and achieve an improvement in fuel consumption.
[0014]
[Means for Solving the Problems]
The hydraulic control device for a continuously variable transmission according to the present invention includes a pulley pulley having a variable pulley groove width mounted on a primary shaft, and a pulley groove width mounted on a secondary shaft and a belt spanned between the primary pulley. A hydraulic control device for a continuously variable transmission having a variable secondary pulley, the drive oil chamber being provided in the primary pulley for applying a drive hydraulic pressure to the primary pulley, and a direction opposite to a centrifugal oil pressure generated in the drive oil chamber A primary cylinder having a balance oil chamber for applying a centrifugal oil pressure to the primary pulley; a drive oil chamber provided in the secondary pulley for applying a drive oil pressure to the secondary pulley; and a centrifugal oil pressure generated in the drive oil chamber in a reverse direction A secondary cylinder having a balance oil chamber that applies the centrifugal hydraulic pressure of the secondary pulley, A lubrication pressure path for supplying hydraulic oil to each lubrication unit excluding the forward / reverse switching mechanism of the continuously variable transmission; A balance oil passage connecting a cooling passage provided with an oil cooler and each of the balance oil chambers; A lubricating oil supply passage for supplying hydraulic oil of the balance oil passage to a lubricating portion of the forward / reverse switching mechanism; Hydraulic oil that has passed through the oil cooler And the lubrication part of the forward / reverse switching mechanism It is characterized in that it is supplied to.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0017]
FIG. 1 is a schematic diagram showing an example of a drive system of a belt type continuously variable transmission, that is, a CVT. The rotation of a crankshaft 1 driven by an engine (not shown) is a torque converter 2 as a starting device and a forward / reverse switching mechanism. 3 is transmitted to the continuously variable transmission mechanism 4.
[0018]
The torque converter 2 has a lockup clutch 5, and the lockup clutch 5 is connected to the turbine shaft 6. One side of the lockup clutch 5 is a supply chamber, that is, an apply chamber 7a, and the other side is an open chamber, that is, a release chamber 7b. By circulating the hydraulic pressure supplied into the release chamber 7b through the apply chamber 7a, a torque converter is provided. 2 becomes an operation state. On the other hand, by supplying hydraulic pressure to the apply chamber 7a and lowering the hydraulic pressure in the release chamber 7b, the lock-up clutch 5 is engaged with the front cover 8 to be in a lock-up state. Slip pressure control is performed such that the lockup clutch 5 is slid by adjusting the pressure in the release chamber 7b.
[0019]
The forward / reverse switching mechanism 3 includes a forward clutch 11 for transmitting the rotation of the turbine shaft 6, which is an output shaft of the torque converter 2, to the continuously variable transmission mechanism 4, and a reverse brake 12 for transmitting the reverse direction. When the forward clutch 11 is connected by supplying hydraulic pressure to the clutch oil chamber 11a, the rotation of the turbine shaft 6 is transmitted in the positive direction to the continuously variable transmission mechanism 4, and is supplied to the brake oil chamber 12a. When the hydraulic pressure is supplied and the reverse brake 12 is connected, the speed is reduced and transmitted in the reverse direction.
[0020]
The continuously variable transmission mechanism 4 has an input shaft or primary shaft 13 connected to the forward / reverse switching mechanism 3 and an output shaft or secondary shaft 14 parallel to the input shaft. A primary pulley 15 is provided on the primary shaft 13, and the primary pulley 15 is slidable in the axial direction by a ball spline or the like on the primary shaft 13 opposite to the fixed pulley 15 a fixed to the primary shaft 13. A movable pulley 15b to be mounted is provided, and the interval between the cone surfaces of the pulley, that is, the pulley groove width is variable. A secondary pulley 16 is provided on the secondary shaft 14, and the secondary pulley 16 slides in the axial direction on the secondary shaft 14 in the same manner as the movable pulley 15 b facing the fixed pulley 16 a fixed to the secondary shaft 14. The pulley has a movable pulley 16b that is freely mounted, and the groove width of the pulley is variable.
[0021]
A belt 17 is stretched between the primary pulley 15 and the secondary pulley 16, and the groove width of both pulleys 15, 16 is changed to change the ratio of the winding diameter with respect to each pulley 15, 16. As a result, the rotation of the primary shaft 13 is continuously shifted and transmitted to the secondary shaft 14.
[0022]
The rotation of the secondary shaft 14 is transmitted to wheels 19a and 19b via a gear train having a reduction gear and a differential device 18, and in the case of a front wheel drive vehicle, the wheels 19a and 19b are front wheels. The basic structure of the CVT drive system described above is disclosed in, for example, Japanese Patent Laid-Open No. 10-325458.
[0023]
FIG. 2 is a view showing a specific structure of the continuously variable transmission mechanism 4 shown in FIG. 1. In order to change the groove width of the primary pulley 15, a plunger 21 having a cylindrical portion and a disk portion on the primary shaft 13. Is fixed, and a primary cylinder 22 slidably contacting the outer peripheral surface of the plunger 21 is fixed to the movable pulley 15b. A drive oil chamber 23a is formed between the plunger 21 and the movable pulley 15b. . On the other hand, a balance oil chamber 23 b is formed between the cover 24 provided at the open end of the primary cylinder 22 and the plunger 21.
[0024]
In order to change the groove width of the secondary pulley 16, a plunger 26 having a tapered cylindrical portion is fixed to the secondary shaft 14, and the secondary cylinder 27 slidably contacting the outer peripheral surface of the plunger 26 is movable pulley 16 b. A drive oil chamber 28a is formed between the plunger 26 and the movable pulley 16b. On the other hand, a balance oil chamber 28 b is formed between the cover 29 provided at the opening end of the secondary cylinder 27 and the plunger 26.
[0025]
Therefore, when hydraulic oil is supplied into the drive oil chamber 23a in the primary cylinder 22 and its volume is increased, the movable pulley 15b moves to the fixed pulley 15a side together with the cylinder 22 to reduce the pulley groove width and reduce the volume. Then, the pulley groove width becomes wide. Further, the hydraulic oil is supplied into the drive oil chamber 28a in the secondary cylinder 27 to increase its volume. The movable pulley 15b moves to the fixed pulley 16a side together with the cylinder 27 to reduce the pulley groove width and reduce the volume. Then, the pulley groove width becomes wide.
[0026]
An oil supply port 31a communicating with the drive oil chamber 23a is formed in the primary shaft 13 for supplying the operation oil to the drive oil chamber 23a in the primary cylinder 22, and a cover 24 is provided for supplying the operation oil to the balance oil chamber 23b. An oil supply plug 31b is arranged to face the opening formed by the plunger 21.
[0027]
On the other hand, in order to supply hydraulic oil into the drive oil chamber 28a in the secondary cylinder 27, the secondary shaft 14 is formed with an oil supply port 32a communicating with the drive oil chamber 28a, and supplies the hydraulic oil into the balance oil chamber 28b. For this purpose, an oil supply nozzle 32 b is arranged in communication with the oil passage 33 formed in the secondary shaft 14.
[0028]
Accordingly, when the CVT is operating, centrifugal oil pressure is generated in the drive oil chamber 23a by the rotation of the primary pulley 15, and this centrifugal oil pressure acts in the direction of pressing the belt 17 against the movable pulley 15b. A centrifugal oil pressure in the reverse direction is generated in the balance oil chamber 23b. Similarly, centrifugal oil pressure is generated in the drive oil chamber 28a by the rotation of the secondary pulley 16, but centrifugal oil pressure in the opposite direction to this direction is generated in the balance oil chamber 28b.
[0029]
FIG. 3 is a circuit diagram showing a CVT hydraulic control device. The torque converter 2, the forward / reverse switching mechanism 3 and the continuously variable transmission mechanism 4 shown in FIG. 1 are operated by hydraulic pressure from an oil pump 34 driven by an engine. It is supposed to be.
[0030]
The suction port of the oil pump 34 communicates with the oil pan 35 through an oil strainer 36 provided in the oil pan 35, and the discharge port of the oil pump 34 is connected to the oil supply port 32a by a secondary pressure path, that is, a line pressure path 40. In addition, the secondary pressure port of the secondary valve 42 is connected. By this secondary valve 42, the secondary pressure supplied to the drive oil chamber 28a is adjusted to a predetermined pressure and controlled to a value commensurate with the transmission capacity required for the belt 17. That is, when the engine output is large, such as uphill or sudden acceleration, the secondary pressure is increased to prevent the belt 17 from slipping, and when the engine output is small, the secondary pressure is decreased to reduce the loss of the oil pump 34 and the transmission efficiency. Improvement is achieved.
[0031]
The line pressure path 40 is connected to the line pressure port of the primary valve 41, and the primary pressure port of the primary valve 41 is connected to the oil supply port 31 a via the primary pressure path 43. The primary pressure is adjusted by the primary valve 41 to a value corresponding to the target gear ratio, the vehicle speed, and the like, and the vehicle speed is controlled by changing the groove width of the primary pulley 15.
[0032]
The line pressure path 40 is connected to a clutch pressure path 45 via a clutch pressure valve 44, and the clutch oil chamber 11 a of the forward clutch 11 and the reverse brake 12 of the forward / reverse switching mechanism 3 are connected via this clutch pressure path 45. The hydraulic oil of the clutch pressure is supplied to the brake oil chamber 12a and the apply chamber 7a of the lockup clutch 5. The clutch pressure in the clutch pressure path 45 is adjusted with the line pressure as the original pressure. When the external pilot pressure is supplied to the clutch pressure valve 44, the hydraulic pressure in the clutch pressure path 45 is set to a low pressure, When the supply of the external pilot pressure is stopped, the pressure is set higher than when the supply is performed.
[0033]
A lubrication pressure path 46 is connected to the drain port of the secondary valve 42, and hydraulic oil is supplied to the lubrication part of the forward / reverse switching mechanism 3, the lubrication part of the belt 17, and the like by this lubrication pressure path 46. Yes. The lubrication pressure in the lubrication pressure path 46 is adjusted by the lubrication pressure valve 47 using the drain pressure of the secondary valve 42 as a source pressure.
[0034]
Connected to the apply pressure path 51 connected to the apply chamber 7a of the lockup clutch 5, the release pressure path 52 connected to the release chamber 7b, the brake switching pressure path 53 connected to the brake oil chamber 12a, and the clutch oil chamber 11a. A switch valve 55 is provided to control the connection between the clutch switching pressure path 54 and the above-described lubrication pressure path 46 and clutch pressure path 45.
[0035]
This switch valve 55 has four parts each having a three-port switching valve structure, and as shown in FIG. 3, is locked in the F & R mode when the external pilot pressure is not applied, that is, when the vehicle speed is equal to or lower than a predetermined value. It operates in two positions: the disengaged position of the up-clutch 5 and the engagement position of the lock-up clutch 5 in a state where the external pilot pressure is applied.
[0036]
4A is a cross-sectional view showing details of the switch valve 55 in the open position of the lock-up clutch 5, and FIG. 4B is a cross-sectional view showing details of the switch valve 55 in the engagement position of the lock-up clutch 5. It is.
[0037]
In the open position, as shown in FIGS. 3 and 4A, the lubrication pressure path 46 and the release pressure path 52 are in communication with each other by the switch valve 55, and a cooling path 57 provided with an oil cooler 56 is provided. The apply pressure path 51 is in communication.
[0038]
An ATF filter 60 is provided in the cooling passage 57 and a balance oil passage 59 is connected thereto. The balance oil passage 59 is connected to the balance oil chamber 23 b formed in the primary cylinder 22 of the primary pulley 15 and the secondary pulley 16. It is connected to a balance oil chamber 28b formed in the secondary cylinder 27.
[0039]
Therefore, when the switch valve 55 is in the open position, the torque circuit 2 operates in the hydraulic circuit, and the hydraulic control of the forward / reverse switching mechanism 3 becomes possible, that is, the F & R mode. At this time, the hydraulic oil set to the lubricating pressure is It is supplied to the release chamber 7b, discharged from the apply chamber 7a, passes through the oil cooler 56, and then supplied to the respective balance oil chambers 23b and 28b via the balance oil passage 59.
[0040]
On the other hand, in the engaged position, as shown in FIG. 4B, the clutch pressure path 45 and the apply pressure path 51 are in communication with each other, and the hydraulic oil set to the clutch pressure is supplied to the apply chamber 7a. The At this time, the slip pressure path 58 connected to the clutch pressure path 45 is communicated with the release pressure path 52. A slip pressure adjusting valve 61 is provided in the slip pressure path 58, and the slip pressure adjusting valve 61 controls the slip pressure supplied to the slip pressure path 58 according to the external pilot pressure supplied to the external pilot chamber. The pressure is controlled to an arbitrary pressure within the range from the same pressure as the clutch pressure to a pressure of 0. Therefore, when the slip pressure becomes zero, the lockup clutch 5 is engaged and the lockup mode is set, and when the slip pressure becomes the same, the lockup clutch 5 is released. The slip control of the lockup clutch 5 that controls the rotational difference of the lockup clutch 5 to be constant can be performed by appropriately controlling the slip pressure. When the switch valve 55 is in the engaged position, the hydraulic oil from the lubricating pressure passage 46 flows through the cooling passage 57 via the switch valve 55 and is cooled, and then the respective balance oil chambers via the balance oil passage 59. 23b and 28b.
[0041]
As described above, the hydraulic oil is always supplied to the oil cooler 56 by the lubricating pressure regardless of the operating state of the switch valve 55.
[0042]
In order to supply the external pilot pressure to the slip pressure adjusting valve 61, a pilot pressure path 62 is connected between the pilot port of the slip pressure adjusting valve 61 and the clutch pressure path 45. In order to control the pilot pressure, a pilot pressure adjusting valve 63 is provided, and this pilot pressure adjusting valve 63 is operated by energizing the solenoid 63a.
[0043]
A manual valve 65 and a reverse signal valve 66 that are interlocked with each other are connected to a control lever for switching the driving mode, that is, a select lever 64 provided in the passenger compartment, and each of the valves 65 and 66 is connected to the select lever 64. 5 positions corresponding to the P (parking) range, R (reverse) range, N (neutral) range, D (drive) range, and Ds (sport drive) range set by.
[0044]
A pilot pressure passage 67 that connects the clutch pressure passage 45 to the external pilot chamber of the switch valve 55 via the reverse signal valve 66 is provided with a three-port solenoid type switching valve 68. When the solenoid 68a of the switching valve 68 is energized, the switch valve 55 is in the lockup control position, that is, the position where the lockup clutch 5 is engaged. When the solenoid 68a is deenergized, the switch valve 55 is in the F & R mode position as shown in FIG. . The pilot pressure path 67 is connected to the external pilot chamber of the clutch pressure valve 44 as indicated by a broken line, and when the reverse signal valve 66 is set to any of the N position, D position and Ds position, the clutch pressure valve The clutch pressure is supplied to the external pilot chamber 44, and the clutch pressure is set to a low pressure. On the other hand, when the reverse signal valve 66 is set to a P position and an R position other than the above, the hydraulic pressure is not supplied to the external pilot chamber of the clutch pressure valve 44, and the clutch pressure is set to a pressure higher than the above. The
[0045]
A common switching pressure passage 69 is provided between the switch valve 55 and the manual valve 65, and this switching pressure passage 69 communicates with the slip pressure passage 58 when the switch valve 55 is in the F & R mode position. Is in the lockup control position, it communicates with the clutch pressure path 45. When the manual valve 65 is set to either the D range or the Ds range by operating the select lever 64, the switching pressure path 69 is in communication with the clutch switching pressure path 54 via the manual valve 65 and is set to the R range. When this is done, the brake switching pressure passage 53 is brought into communication.
[0046]
Next, when the required supply amount of hydraulic oil in the balance oil chambers 23b and 28b is obtained, when the pulley is stopped, the hydraulic oil is accumulated in the lower portion of the balance oil chamber 23b up to the opening portion of the balance oil chamber 23b. When rotating, the hydraulic oil comes into close contact with the inner peripheral surface of the cylindrical portion of the balance oil chamber 23b by centrifugal force. Originally, when the pulley is stopped, the balance oil chamber 23b does not hold enough hydraulic oil to be filled. Therefore, in order to obtain a sufficient centrifugal hydraulic pressure, it is necessary to supply the insufficient hydraulic oil.
[0047]
Further, when the pulley shifts to the high speed stage side, hydraulic oil is supplied to the drive oil chamber 23a of the primary pulley 15 to increase the volume of the drive oil chamber 23a, and to decrease the volume of the balance oil chamber 23b. become. At this time, the volume of the balance oil chamber 28b of the secondary pulley 16 increases.
[0048]
On the other hand, when the pulley shifts to the low speed stage side, the volume of the balance oil chamber 23b of the primary pulley 15 increases and the volume of the balance oil chamber 28b of the secondary pulley 16 decreases.
[0049]
Thus, the volume of the balance oil chambers 23b and 28b of the primary pulley 15 and the secondary pulley 16 changes every time the pulley performs a speed change operation. Here, since the hydraulic oil supplied to the oil cooler 56 is secured in a certain amount as described above, the balance oil chambers 23a and 28b are always filled with the hydraulic oil by the hydraulic oil supplied from here. It is possible to keep.
[0050]
Accordingly, since the supply of hydraulic oil to the balance oil chambers 23b and 28b, which is necessary when the pulley is operated, can be secured by the supply amount to the oil cooler 56, the balance oil chambers 23a and 28b are supplied to the respective balance oil chambers 23a and 28b. The hydraulic oil can be supplied only by the hydraulic oil supplied to the oil cooler 56, the amount of oil supplied to the entire lubrication pressure path is reduced, the mechanical loss of the oil pump 34 is reduced, and the fuel consumption is improved. It becomes possible.
[0051]
The amount of oil supplied to each of the lance oil chambers 23b and 28b can be adjusted by providing an orifice or a throttle in the balance oil passage 59.
[0052]
FIG. 5 illustrates the present invention. one 1 shows a hydraulic control apparatus according to an embodiment hydraulic FIG. 5 is a circuit diagram, and in FIG. 5, members common to the members shown in FIG.
[0053]
In this case, a lubricating oil supply path 70 is connected to the balance oil path 59, and hydraulic oil that has passed through the oil cooler 56 is supplied to the lubricating portion of the forward / reverse switching mechanism 3 by this lubricating oil supply path 70. It is like that.
[0054]
Normally, a certain amount of hydraulic oil is supplied to the oil cooler 56, and the amount of oil supplied to the balance oil chambers 23b and 28b of the primary pulley 15 and the secondary pulley 16 is the required oil amount that matches the volume change. However, since the hydraulic oil supplied from the oil cooler 56 is constant regardless of the speed change state of the pulley, the capacity of the balance oil chambers 23b and 28b does not change when the pulley is not changing speed. The oil overflows from the balance oil chamber. If there is a large amount of hydraulic oil around the pulley, it becomes a stirring resistance, so it is necessary to minimize the amount of oil supplied to the balance oil chamber. However, since the amount of oil supplied to the oil cooler 56 is determined by the amount of heat released from the transmission, generally a large amount of hydraulic oil is supplied to the balance oil chamber relative to the required amount of oil supplied to the balance oil chamber. . Therefore, the hydraulic oil supplied from the lubrication pressure path to the forward / reverse switching mechanism 3 for lubrication uses the excess of the hydraulic oil passing through the oil cooler 56, excluding the hydraulic oil supplied to the balance oil chamber. By doing so, it is possible to reduce the required amount of oil in the lubrication pressure path and to reduce the stirring resistance due to excessive hydraulic oil in the pulley.
[0055]
The amount of oil supplied to the lance oil chambers 23b and 28b and the lubrication part of the forward / reverse switching mechanism 3 can be adjusted by providing an orifice, a throttle, or the like in the balance oil passage 59 or the lubricating oil supply passage 70.
[0056]
It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the drive system of the belt type continuously variable transmission is not limited to the case shown in FIG. 1, and the present invention can be applied to various types such as a type that does not have the torque converter 2.
[0057]
【The invention's effect】
According to the present invention, the hydraulic oil that has passed through the oil cooler is supplied to the respective balance oil chambers of the primary pulley and the secondary pulley without being supplied directly from the oil pump. The amount of oil can be reduced.
[0058]
The supply of hydraulic oil to each balance oil chamber is a special method for supplying the lubrication pressure with the required amount of oil when the volume of the balance oil chamber changes at the time of shifting the primary pulley and the insufficient amount of hydraulic oil at the start of rotation. It can be performed from the cooling path without providing an oil path.
[0059]
Lubricating oil can be supplied to the lubricating portion of the forward / reverse switching mechanism from the cooling path via the lubricating oil supply path without being performed via the lubricating pressure path directly supplied from the oil pump.
[0060]
By reducing the required amount of oil flowing through the lubrication pressure path, it is possible to reduce the discharge amount of the oil pump, improve the mechanical loss of the oil pump, and improve fuel efficiency.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an example of a drive system of a belt type continuously variable transmission.
2 is an enlarged cross-sectional view of the continuously variable transmission mechanism shown in FIG.
FIG. 3 is a hydraulic control device for a continuously variable transmission. Basic structure FIG.
4A and 4B are enlarged cross-sectional views of the switch valve shown in FIG. 3, respectively.
FIG. 5 shows the present invention. one 1 is a hydraulic circuit diagram showing a hydraulic control device for a continuously variable transmission according to an embodiment.
[Explanation of symbols]
1 Crankshaft
2 Torque converter
3 Forward / reverse switching mechanism
4 Continuously variable transmission mechanism
5 Lock-up clutch
6 Turbine shaft
7a Apply room
7b Release room
11 Forward clutch
12 Brake for reverse
13 Primary axis
14 Secondary shaft
15 Primary pulley
16 Secondary pulley
22 Primary cylinder
23a Drive oil chamber
23b Balance oil chamber
27 Secondary cylinder
28a Drive oil chamber
28b Balance oil chamber
34 Oil pump
40 line pressure path
41 Primary valve
42 Secondary valve
43 Primary pressure path
44 Clutch pressure valve
45 Clutch pressure path
46 Lubrication pressure path
47 Lubrication pressure valve
55 Switch valve
59 Balance Oilway
70 Lubricating oil supply passage

Claims (1)

Hydraulic pressure of a continuously variable transmission having a primary pulley with a variable pulley groove width mounted on a primary shaft and a secondary pulley with a variable pulley groove width mounted on the secondary shaft and a belt spanned between the primary pulley. A control device,
A primary cylinder having a drive oil chamber that is provided in the primary pulley and applies a drive oil pressure to the primary pulley, and a balance oil chamber that applies a centrifugal oil pressure in a direction opposite to a centrifugal oil pressure generated in the drive oil chamber to the primary pulley;
A secondary cylinder that is provided in the secondary pulley and has a drive oil chamber that applies drive oil pressure to the secondary pulley, and a balance oil chamber that applies centrifugal oil pressure in a direction opposite to the centrifugal oil pressure generated in the drive oil chamber;
A lubrication pressure path for supplying hydraulic oil to each lubrication unit excluding the forward / reverse switching mechanism of the continuously variable transmission;
A balance oil passage connecting a cooling passage provided with an oil cooler and each of the balance oil chambers ;
A lubricating oil supply passage for supplying hydraulic oil of the balance oil passage to a lubricating portion of the forward / reverse switching mechanism ,
The hydraulic control device for a continuously variable transmission, wherein the hydraulic oil that has passed through the oil cooler is supplied to each of the balance oil chambers and the lubrication part of the forward / reverse switching mechanism .

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