JP2824918B2 - Hydraulic control mechanism for continuously variable transmission - Google Patents

Description

The present invention relates to a hydraulic control mechanism for a continuously variable transmission, and in particular, supplies oil from an oil pump to a drive side hydraulic chamber and a driven side hydraulic chamber, respectively. The present invention relates to a hydraulic control mechanism of a continuously variable transmission that controls a hydraulic pressure to change a gear ratio.

2. Description of the Related Art In a vehicle, a transmission is interposed between an internal combustion engine and drive wheels. This transmission changes the driving force of the drive wheels and the traveling speed in accordance with the traveling conditions of the vehicle that vary over a wide range, thereby sufficiently exhibiting the performance of the internal combustion engine. The transmission is formed between both pulley parts of a pulley having a fixed pulley part fixed to the rotating shaft and a movable pulley part attached to the rotating shaft so as to be able to approach and separate from the fixed pulley part. There is a continuously variable continuously variable transmission that changes the radius of rotation of a belt wound around a pulley by increasing or decreasing the width of a groove to transmit power and change the gear ratio (belt ratio).

This continuously variable transmission is disclosed in Japanese Patent Application Laid-Open No. 61-36545. The shift control device of a continuously variable transmission disclosed in this publication is provided with a characteristic changing device that operates when each range for engine braking is selected, as a correction means for correcting engine brake characteristics, Correction is made to reduce the engine rotation in the low vehicle speed range or the middle and low vehicle speed ranges of the range, and the moderate braking force is obtained by eliminating excessive application of the engine brake.

Another example is disclosed in JP-A-61-36554.
The hydraulic control device for a continuously variable transmission disclosed in this publication provides a notch in the outer periphery of a land for controlling line pressure, and disconnects a drain port and a spring chamber when the pump discharge amount in a high rotation range is large. The communication is performed by the chipping, and the excessive increase of the lubricating oil pressure when the pump discharge amount increases is suppressed, and various problems associated with excessive lubrication and line pressure increase are eliminated.

Further, there is one disclosed in JP-A-61-55459.
The hydraulic control device for a continuously variable transmission disclosed in this publication is provided with an accumulator having a predetermined volume near the servo chamber of the output-side sub-pulley, and compensates for a decrease in pump performance at the time of sudden braking by the accumulator. Delays in shifting gears and belt slip during reacceleration are reliably prevented.

[Problems to be Solved by the Invention] In a conventional hydraulic control mechanism for a continuously variable transmission, a valve body is provided below a transmission case of the continuously variable transmission, and oil from an oil pump passes through the valve body. Is supplied to the drive side hydraulic chamber.

For this reason, the increase in the length of the hydraulic passage complicates the passage structure, making it difficult to manufacture, and has the disadvantages of high cost and economic disadvantage.

In addition, if the viscosity of the oil at a low temperature is particularly high due to an increase in the length of the hydraulic circuit, the supply state of the oil may be deteriorated, which may adversely affect the shifting performance, and the shifting performance is reduced. There are inconveniences.

[Object of the Invention] Accordingly, an object of the present invention is to provide a hydraulic passage for supplying oil pressure from one end to a drive-side hydraulic chamber in a drive shaft of a continuously variable transmission, in order to eliminate the above-mentioned disadvantages, The valve body is mounted via a separate plate, an oil pump is mounted at the other end of the drive shaft, and a valve body hydraulic passage is provided inside the valve body to communicate with the hydraulic passage. The hydraulic passage to the side hydraulic chamber and the valve body hydraulic passage can be easily formed, so that the layout is easy, the production cost can be reduced, and the passage length can be reduced to improve the speed changeability. The object is to realize a hydraulic control mechanism for a continuously variable transmission.

[Means for Solving the Problems] In order to achieve this object, the present invention provides a continuously variable transmission in which oil from an oil pump is supplied to a driving-side hydraulic chamber and a driven-side hydraulic chamber, respectively, to change the gear ratio. A hydraulic passage for supplying hydraulic pressure from one end of the drive shaft to the drive-side hydraulic chamber in the drive shaft of the continuously variable transmission, and a valve body via a separate plate at one end of the drive shaft. And an oil pump is mounted at the other end of the drive shaft, and a valve body hydraulic passage communicating with the hydraulic passage is provided in the valve body.

[Operation] With the above-described configuration, when forming the passage from the drive side hydraulic chamber to the drive side hydraulic chamber, the hydraulic passage from the valve body to the drive side hydraulic chamber and the valve body hydraulic passage are easily formed, and the manufacturing cost is reduced. It is inexpensive, and the length of the passage is reduced to improve the speed changeability.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 4 show an embodiment of the present invention. In FIG. 1, reference numeral 2 denotes a continuously variable transmission for changing a gear ratio (belt ratio).

A transmission case 4 is covered outside the transmission 2, and the transmission case 4 includes a left case 6, a right case 8, and a side cover portion 10, as shown in FIG.

As shown in FIG. 1, the belt-driven and continuously variable continuously variable transmission 2 in the left case 6
The driving pulley 14, the driving fixed pulley piece 16, the driving movable pulley piece 18, the driven pulley 20, the driven fixed pulley piece 22, and the driven movable pulley piece 24, The side pulley 14 includes a drive-side fixed pulley part 16 fixed to a drive shaft 26 serving as a rotation shaft, and a drive-side movable pulley mounted on the drive shaft 26 so as to be movable in the axial direction of the drive shaft 26 and non-rotatably. And a piece 18. The driven pulley 20 also has a driven-side fixed pulley piece 22 similar to the drive-side pulley 14.
And a driven-side movable pulley piece 24.

First and second housings 28 and 30 are respectively mounted on the driving-side movable pulley portion 18 and the driven-side movable pulley portion 24, and a first hydraulic chamber 32 as a driving-side hydraulic chamber and a driven-side hydraulic A second hydraulic chamber 34 is formed. At this time, in the second hydraulic chamber 34 on the driven side, there is provided an urging means 36 composed of a spring or the like for urging the second housing 30 in the direction in which the second hydraulic chamber 34 expands.

A valve body 40 is mounted via a separate plate 38 on the side cover 10 side of the left case 6 which is a part of the drive shaft 26, and the left case 6 side of the right case 8 which is the other end of the drive shaft 26. Oil pump 42
Attach.

A hydraulic passage 44 is provided on the drive shaft 26 of the transmission 2 to supply hydraulic pressure from the side cover 10 side end to the first hydraulic chamber 32, and is connected to the hydraulic passage 44 in the valve body 40. A valve body hydraulic passage 46 is provided.

The hydraulic control circuit of the transmission 2 includes, as shown in FIG.
An oil pump is provided in communication with the second hydraulic chamber through a first passage, and a second passage branched from the first passage is provided.
50 is provided in communication with a relief valve 52 for adjusting the line pressure to a predetermined pressure.

The oil pump 42 has a first passage 54 that branches off to
In addition to being connected to the line pressure control valve 56, it is also connected to the second line pressure control valve 60 via the fourth passage 58. The first and second line pressure control valves 56 and 60 are connected by a fifth passage 62.

In addition, the first passage 48 is connected to the ratio control valve 66 by the sixth passage 64.
, A communication with a clutch pressure control valve 70 via a seventh passage 68, and a communication with a solenoid regulator valve 74 via an eighth passage 72.

The ratio control valve 66 is connected to the first hydraulic chamber by the ninth passage 76.
A 10th passage 78 branched from the ninth passage 76 is provided in communication with a cooling control valve 80 for controlling the amount of oil to an oil cooler (not shown).

A loop regulator valve 84 is connected to the oil pump 42 through an eleventh passage 82.

The gear ratio of the continuously variable transmission 2 is determined by the belt rotation radius R1 of the driving pulley 14 and the belt rotation radius of the driven pulley 20.
It is determined by R2 / R1 with R2.

Reference numeral 86 denotes a line solenoid, 88 denotes a ratio solenoid, and 90 denotes a clutch solenoid.

 Next, the operation will be described.

While controlling the line pressure from the oil pump 42, the second
The hydraulic pressure is supplied to the hydraulic chamber 34, the second hydraulic chamber 34 is expanded, and the driven movable pulley portion 24 is pressed against the driven fixed pulley portion 22 side, as shown in FIG. The belt turning radius R2 of is increased. Conversely, the belt rotation radius R1 of the drive side pulley 14 becomes small, and the speed ratio (R2 / R1) becomes maximum.

In addition, the line pressure from the oil pump 42 is supplied to the first hydraulic chamber 32 while being controlled, and the first hydraulic chamber 32 is expanded to press the drive-side movable pulley part 18 toward the drive-side fixed pulley part 16. Then, as shown in FIG. 4, the belt rotation radius R1 of the driving pulley 14 is increased. Conversely, the belt rotation radius R2 of the driven pulley 20 becomes small, and the gear ratio (R2 / R1) becomes minimum.

At this time, the oil supplied to the first hydraulic chamber 32 is
Drive shaft from valve body hydraulic passage 46 in valve body 40
The fluid flows into the hydraulic passage 44 in the inside 26, and flows into the first hydraulic chamber 32 from the hydraulic passage 44.

Thus, the valve body hydraulic passage 46 and the hydraulic passage 44 from the valve body 40 to the first hydraulic chamber 32 can be easily formed, which is practically advantageous.

In addition, the valve body hydraulic passage 46 and the hydraulic passage 44 have a smaller passage length than the conventional one to simplify the configuration, so that the manufacturing cost can be reduced, which is economically advantageous, and the drive shaft 26 This facilitates the layout of the side cover 10 side end.

Further, by reducing the length of the passage, there is no fear that the oil supply condition is deteriorated particularly when the viscosity of the oil at a low temperature is high. Can be reliably prevented.

Furthermore, by arranging the valve body 40 and the oil pump 42 on both end portions of the drive shaft 26, that is, on the same axis as that of the drive shaft 26, it is possible to save space and shorten the oil passage. Yes, practically advantageous.

A separate plate is provided at one end of the drive shaft 26.
By mounting the valve body 40 via 38, the degree of freedom of the layout of the oil passage can be improved by the separate plate 38, and the sealing performance of the oil passage can also be improved.

[Effects of the Invention] As described in detail above, according to the present invention, a hydraulic passage for supplying hydraulic pressure from one end to a drive side hydraulic chamber is provided in a drive shaft of a continuously variable transmission, and a separate plate is provided at one end of the drive shaft. The valve body is mounted via the valve shaft, an oil pump is mounted on the other end of the drive shaft, and a valve body hydraulic passage that connects to the hydraulic passage is provided inside the valve body. The valve body hydraulic passage and the hydraulic passage can be easily formed, which is practically advantageous. Also, the valve body hydraulic passage and the passage length of the hydraulic passage are made smaller than the conventional one to simplify the configuration, so that the manufacturing cost can be reduced and it is economically advantageous, and at the same time, one end of the drive shaft is provided. The layout becomes easy, and there is no fear that the oil supply condition is deteriorated especially when the viscosity of the oil at a low temperature is high, so that good shifting performance can be maintained, and a reduction in shifting performance can be reliably prevented. Things. Further, by arranging the valve body and the oil pump on both ends of the drive shaft, that is, on the same axis, space can be saved,
The oil passage can be shortened, which is practically advantageous. Furthermore, by mounting the valve body via a separate plate at one end of the drive shaft, the flexibility of the layout of the oil passage can be improved by the separate plate, and the sealing performance of the oil passage is also improved. obtain.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a partially cutaway sectional view of a continuously variable transmission, FIG. 2 is a schematic diagram of a hydraulic control circuit of the transmission, and FIG. Pulley belt turning radius R1
FIG. 4 is a schematic cross-sectional view showing a state of a maximum gear ratio (R2 / R1) based on the belt rotation radius R2 of the driven pulley and a belt rotation radius R1 of the driven pulley and FIG. It is a schematic sectional view showing the state of the minimum speed change ratio (R2 / R1) by R2. In the figure, 2 is a continuously variable transmission, 12 is a belt, 14 is a driving pulley, 16 is a driving fixed pulley piece, 18 is a driving movable pulley piece, 20 is a driven pulley, and 22 is a driven pulley. Fixed pulley piece, 24 is driven side movable pulley piece, 26 is drive shaft, 32
Is the first hydraulic chamber, 34 is the second hydraulic chamber, 40 is the valve body, 42
Is an oil pump, 44 is a hydraulic passage, 46 is a valve body hydraulic passage, 52 is a relief valve, 56 is a first line pressure control valve,
60 is a second line pressure control valve, 66 is a ratio control valve, 70 is a clutch pressure control valve, 74 is a solenoid regulator valve, 80
Is a cooling control valve, 84 is a lube regulator valve,
86 is a line solenoid, 88 is a ratio solenoid, and 90 is a clutch solenoid.

Claims (1)

(57) [Claims] 1. A hydraulic control mechanism for a continuously variable transmission for changing a gear ratio by supplying oil from an oil pump to a driving side hydraulic chamber and a driven side hydraulic chamber, respectively. A hydraulic passage for supplying oil pressure from one end of the drive shaft to the drive side hydraulic chamber is provided, a valve body is mounted on one end of the drive shaft via a separate plate, and an oil pump is mounted on the other end of the drive shaft. A hydraulic control mechanism for a continuously variable transmission, wherein a valve body hydraulic passage communicating with the hydraulic passage is provided in the valve body.