JPH0443640Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a hydraulic control circuit for a vehicle automatic transmission, in which a hydraulic line is used to supply line pressure and back pressure line pressure to the back pressure chambers of the governor and accumulator. The present invention relates to a structure, and particularly to a structure in which an oil passage for communicating the governor and an accumulator can be simplified.

[Prior Art] In general, an automatic transmission for a vehicle selectively inputs the output from a torque converter to each sun gear etc. of a transmission gear device consisting of planetary gears using an input path switching device equipped with a plurality of clutches. It is configured as follows. Each of these clutches is driven and controlled by a hydraulic control circuit using hydraulic pressure according to the driving condition of the vehicle and transmission torque characteristics of the transmission.One of the signals representing this driving condition is the output of the transmission. A governor attached to the shaft extracts governor hydraulic pressure according to the rotational speed of the output shaft, that is, the vehicle speed. Further, in such automatic transmissions, in order to smoothly perform gear changes, the rising characteristics of hydraulic pressure are controlled by, for example, an accumulator.

[Problem that the invention attempts to solve]

By the way, in the above oil passage structure, it is necessary to communicate the governor and the back pressure chamber of the accumulator, but depending on the arrangement position of these devices, the oil passage for this communication may become complicated. There is a fear.

SUMMARY OF THE INVENTION In view of the above-mentioned concerns, an object of the present invention is to provide an oil passage structure in a hydraulic control circuit of an automatic transmission for a vehicle, which can simplify the oil passages of a governor and an accumulator.

[Means for solving problems]

The present invention provides a hydraulic control circuit that operates the clutch, etc. of a vehicle automatic transmission in accordance with vehicle speed, etc.
The governor, which generates governor oil pressure according to vehicle speed, is placed above the valve body mounting surface of the transmission case, and the back pressure chamber of the accumulator, which controls the rise characteristics of the oil pressure, is located below the governor and near the valve body mounting surface. A line pressure oil passage extending from the valve body mounting surface to the governor is formed, and a branch oil passage communicating with the back pressure chamber of the accumulator is formed in the middle of the line pressure oil passage. It has an oil passage structure.

[Effect]

According to the oil passage structure of the present invention, since the accumulator is disposed below the governor disposed on the upper part of the transmission case and near the valve body mounting surface of the transmission case, the governor The line pressure oil passage extending to the line pressure passage passes near the back pressure chamber of this accumulator, and therefore, it is possible to communicate the accumulator back pressure chamber and the governor by simply extending a branch oil passage from this line pressure oil passage. As a result, the oil passage for communication between the governor and the accumulator can be greatly simplified.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 4 are diagrams for explaining an oil passage structure in a hydraulic control circuit of an automatic transmission for a vehicle according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a four-speed automatic transmission for automobiles to which this embodiment is applied, which includes a torque converter 2 with a lock-up mechanism, a speed change gear device 3 equipped with a Ravigneaux gear train, and an input path switching device 4. The engine output is transmitted via the input shaft of the torque converter 2 to the sun gear or pinion gear of the transmission gear device 3 by the first to third clutches of the input path switching device 4. The signal is selectively input to the carrier, where the speed is appropriately changed, and then taken out from the ring gear 5.

Further, a reduction gear 6 is spline-fitted to the boss portion of the ring gear 5.
is meshed with the input gear 7a of the counter shaft 7, and the output gear 7b is meshed with the ring gear 8a of the differential gear device 8, and a wheel is attached to the tip of the output shaft 8b.

The counter shaft 7 is disposed in the upper part of the transmission case 1a in which the speed change gear device 3 and the input path switching device 4 are housed, parallel to the axes of the devices 3 and 4. A governor 9 is disposed slightly above the counter shaft 7. A pinion gear 9b formed on a drive shaft 9a of this governor 9 meshes with a drive gear 7c attached to the counter shaft 7 by spline fitting, so that the governor 9 can control the output rotational speed of the transmission 1, That is, the governor oil pressure is generated according to the vehicle speed.

Further, an oil pan mounting surface 1b is formed at the lower peripheral edge of the transmission case 1a,
An oil pan 10 is attached to the attachment surface 1b. Also, the above oil pan mounting surface 1
A valve body mounting surface 1c is formed on the inside of b and is flush with the valve body mounting surface 1c, and a valve body 14 consisting of various control valves is mounted on the mounting surface 1c.

A pair of accumulators 11 are formed in the vicinity of the valve body mounting surface 1c of the transmission case 1a. This accumulator 1
1 is constructed by disposing a piston 11b slidably in the axial direction in a back pressure chamber 11a and biased upward by a biasing spring 11c. The hydraulic pressure is maintained at a predetermined pressure and the rising characteristics of the hydraulic pressure are controlled.

Further, a line pressure oil passage 13 is formed between the pair of accumulators 1 and 11 of the transmission case 1a, extending from the valve body mounting surface 1c to the governor 9 and returning from the governor 9 to the valve mounting surface 1c. has been done. The inflow oil passage 13a of this line pressure oil passage 13 communicates with an inner oil passage 9c bored in the governor shaft 9a of the governor 9, and an outer oil passage 9c formed around the inner oil passage 9c. The oil passage 9d is connected to the inside of the valve body 14 through the outflow oil passage 13b. A branch oil passage 13c is formed in the middle of the inflow oil passage 13a, and the branch passage 13c is connected to the back pressure chamber 11.
It is communicated within a.

Next, the effects of this embodiment will be explained.

In the hydraulic control circuit of this embodiment, line pressure, for example, D range pressure, is supplied from the inflow oil passage 13a of the line pressure oil passage 13 to the governor 9 through the inner oil passage 9c, and in the governor 9, the transmission The governor pressure is controlled according to the rotational speed of the counter shaft 7, which is the output shaft, that is, the vehicle speed, and then returns to the valve body 14 through the outer oil passage 9d and the outflow oil passage 13b. At this time, the D range pressure is also supplied to the back pressure chamber 11a of the accumulator 11 through the branch oil passage 13c of the inflow oil passage 13a.

Here, the above-mentioned accumulator 11 and governor 9
Depending on the arrangement position of each oil passage 13a,
13c will be routed over a long distance, and there is a risk that the oil passage structure in this part will become complicated. On the other hand, in this embodiment, the governor 9 is arranged at the upper part of the transmission case 1a corresponding to the position of the counter shaft 7, and the accumulator 11 is arranged directly below the governor 9 and at the valve body mounting surface 1c. Because of this arrangement, transmission oil can be supplied to the back pressure chamber 11a of the accumulator 11 by simply extending the branch oil passage 13c from the inflow oil passage 13a to the governor 9, and the oil passage route is simplified accordingly. can be converted into

In the above embodiment, the case where there is a pair of accumulators 11 has been described, but the present invention can of course be applied to cases where there is one accumulator 11 or three or more accumulators 11.

[Effect of idea]

As described above, according to the oil passage structure in the hydraulic control circuit of the automatic transmission for vehicles according to the present invention, the governor is disposed in the upper part of the transmission case, the accumulator is disposed below this, and the oil passage to the governor is arranged. Since a branch oil passage is formed in and communicated with the back pressure chamber of the accumulator, the oil passage can be greatly simplified.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional rear view of the governor and accumulator portion for explaining the oil passage structure according to an embodiment of the present invention, Fig. 2 is a cross-sectional side view of the accumulator portion, Fig. 3 is a bottom view thereof, and Fig. 4 FIG. 2 is a cross-sectional plan view of an automatic transmission employing the above structure. In the figure, 1 is an automatic transmission, 1a is a transmission case, 1c is a valve body mounting surface, 2 is a torque converter, 3 is a transmission gear device, 4 is an input path switching device, 9 is a governor, 11 is an accumulator, and 11a is a backrest. Pressure chamber, 13 is line pressure oil passage, 13
c is a branch oil path.

Claims (1)

[Scope of utility model registration request] Hydraulic control for operating a clutch, etc. of the input path switching device in accordance with the vehicle speed, etc. of an automatic transmission for a vehicle, in which the output from the torque converter is selectively input to the transmission gear device by the input path switching device. The circuit has an oil passage structure for supplying back pressure line pressure to a governor that generates governor hydraulic pressure according to vehicle speed and an accumulator that controls the rising characteristics of hydraulic pressure, and the governor is connected to a valve body of a transmission case. The accumulator is disposed above the mounting surface, and the back pressure chamber of the accumulator is disposed below the governor and near the valve body mounting surface to form a line pressure oil passage extending from the valve body mounting surface to the governor. An oil passage structure for an automatic transmission for a vehicle, characterized in that a branch oil passage is formed in the middle of the line pressure oil passage, and the branch oil passage is communicated with a back pressure chamber of the accumulator.