JPS646439Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) The present invention relates to a hydraulic pressure control device for an automatic transmission that reduces unnecessary line pressure to improve fuel efficiency. (Prior Art) Examples of hydraulic circuits for conventional automatic transmission hydraulic pressure control devices include those shown in Figures 1 and 2 (Nissan Full Automatic 3N71B).
Mold maintenance manual Figure 51 Hydraulic circuit diagram, September 1972
Published by Nissan Motor Co., Ltd.). The pressure regulator valve 31 in the hydraulic circuit of the hydraulic pressure control device of this automatic transmission is as shown in FIG.
Throttle pressure is input to the lower end of the spool 41 from the port 16 communicating with the vacuum throttle valve 32, and when the vehicle speed increases and the governor pressure of the governor valves 34 and 35 increases, the throttle pressure is input through the pressure modifier valve 33. Throttle pressure input from the port 18 to the upper end of the spool 42, biasing pressure of the spring 39 interposed between the spools 41 and 42, or the spool 41 in the backward range from the port 6 communicating with the manual valve 37. The discharge from the oil pump 38 that flows into the port 20 that communicates with the oil pump 38 is related to the line pressure that is input to the recess 41a (the lower surface has a smaller pressure receiving area than the upper surface) through the manual valve 37. The oil pressure (line pressure) can be adjusted. The manual valve 37 is manually switched to the reverse range R, travel ranges D, 1, 2, neutral range N, and parking range P (first
The figure shows the manual valve 37 in the neutral range). However, in such a conventional automatic transmission hydraulic pressure control device, the manual valve 37
Only the signal pressure of the reverse range R is input from the manual valve 37 to the port 6 of the pressure regulator valve 31 which communicates with
1, 2. Since signal pressures for neutral range N and parking range P are not input, assuming the conditions of the throttle pressure and governor pressure are constant, the line pressure is transferred from the manual valve 37 to the reverse range R.
It is determined whether the signal pressure is input or not. That is, the line pressure is the same in ranges D, 1, 2, P, and N other than the reverse range R. This means that the parking range P and neutral range N, which are unrelated to power transmission, have the same line pressure as the driving ranges D, 1, and 2. Since the line pressures in the parking range P and the neutral range N are used only for circulating lubricating oil, it is sufficient that the line pressures are lower than the line pressures in the driving ranges D, 1, and 2. Therefore, unnecessary line pressure is generated and an unnecessary load is placed on the oil pump 38, which not only worsens fuel efficiency, but also deteriorates startability at low temperatures and causes oil leakage during warm-up. There is a problem in that the pump 38 may generate abnormal noise due to cavitation or the like. (Purpose of the invention) Therefore, the present invention makes it possible to input a signal from the manual valve 37 to the pressure regulator valve 31 not only in the reverse range R but also in the traveling range D. valve 3
1 is the line pressure when no signal from reverse range R or travel range D, 1, or 2 is input than the line pressure when any signal from reverse range R or travel range D, 1, or 2 is input. By lowering the fuel consumption, it improves fuel efficiency, improves starting performance at low temperatures, and reduces oil pump 3 during warm-up.
The purpose is to prevent abnormal noise from being generated from 8. (Structure of the invention) The hydraulic pressure control device for an automatic transmission according to the invention includes a manual valve that can output a reverse range or travel range signal to one or both of a front clutch and a rear clutch, and a manual valve that outputs a reverse range or a travel range signal. a pressure regulator valve that can input a signal to adjust the line pressure of fluid discharged from the oil pump using a spool and a biasing member that biases the spool toward the pressure increasing side of the fluid pressure; In the hydraulic pressure control device for an automatic transmission, the pressure regulator valve is provided with two ports for inputting signals from the manual valve, and when the manual valve is in the reverse range, the first port is connected to the pressure regulator valve. supplying hydraulic pressure, supplying hydraulic pressure to the second port when the manual valve is in the travel range, and applying the biasing member according to the hydraulic pressure supplied to either the first or second port. It is characterized by increasing the biasing force of. (Actions and effects of the invention) According to this configuration, that is, technical means,
By adjusting the area difference between each land of the spool, the line pressure in the parking range P and neutral range N can be made lower than the line pressure in the reverse range R or driving ranges D, 1, and 2. It is possible to prevent an unnecessary load from being placed on the oil pump 38 by creating unnecessary line pressure in the liquid discharged from the pump 38. Therefore, not only can fuel efficiency be improved, but also startability at low temperatures can be improved, and abnormal noises from the oil pump 38 can be prevented from being generated during warm-up. (Example) Hereinafter, an example of the present invention will be described based on the drawings. 3 to 5 are diagrams showing an embodiment of the present invention. Note that the same parts as in the conventional hydraulic circuit diagram are given the same reference numerals. First, to explain the configuration, as shown in the hydraulic circuit diagram in FIG. 25,
2-3 Shift valve 26, pressure modifier valve 33, vacuum throttle valve 3
2. Throttle backup valve 28, solenoid downshift valve 29, second lock valve 30, 2-3 timing valve 36, governor valves 34, 35, throttle relief valve 44,
It has an orifice check valve 45, a T/C pressure holding valve 46, and relief valves 47, 48, and these valves are connected to each other as shown in FIG. 3, and an oil pump 38 and a torque converter 40 , a front clutch 49, a rear clutch 50, a low reverse brake 51, a brake band 52, a diaphragm vacuum 53, and a downshift solenoid 54, as shown in the figure. As shown in FIG. 4, the pressure regulator valve 31 in this embodiment includes a valve hole 10 having ports 1 to 6, 14, 16, 18, and 20, and a land 42 in sliding contact with the valve hole 10.
a to 42e, and the valve hole 1 is movable in the axial direction.
0, and ports 43a and 4 corresponding to port 6 (first port), port 1 (second port), and port 16, respectively.
3b and 43c and fixed to the lower end of the valve hole 10 in the figure, and lands 41b to 41d that slide on the inner peripheral surface of the sleeve 43 and are housed in the sleeve 43 so as to be movable in the axial direction. spool 41 (biasing member), a spring seat 55 disposed at the upper end of the sleeve 43 in the figure, and a spring 39 (biasing member) interposed between the spring seat 55 and the land 42d of the spool 42. It has Lands 42b, 4 of spool 42
The diameters of 2c and 42d are equal and the diameter of spool 42
The diameter of a is smaller than the diameter of those lands,
Furthermore, the diameter of land 42e is smaller than land 42a. The land 41b of the spool 41 has a larger diameter than the land 41c, and furthermore, the land 41b has a larger diameter than the land 41c.
has a larger diameter than the land 41d. Ports 4 and 5 are drain ports. port 20,
2 and 3 communicate with the oil passage 7 through which oil discharged from the oil pump 38 passes. Orifices 2 are provided at the inlet of port 20 and the outlet of port 14, respectively.
2 and 23 are provided. Port 14 communicates with torque converter 40, port 18 communicates with pressure modifier valve 33, and port 16 communicates with vacuum throttle valve 32 and pressure modifier valve 33. The port 6 is connected to the oil passage 7 via the manual valve 37 when the manual valve 37 is switched to the reverse range R.
Port 5 of manual valve 37 to communicate with
It communicates with 6. Port 1 is connected to port 6 of manual valve 37 so that it communicates with oil passage 7 via manual valve 37 when manual valve 37 is switched to travel range D, 1, or 2.
It communicates with 1. Next, the action will be explained. When the engine is stopped, the oil pump 38 is not driven either.
The spool 42 in the pressure regulator valve 31 is pressed against the upper end of the valve hole 10 by a spring 39, as shown in the right half of FIG. 4, and the spool 41 flows in from the port 16 and remains there. Due to the oil, the land 41b is in contact with the spring seat 55 as shown in the right half of the figure. When the engine rotates and the oil pump 38 is driven and the manual valve 37 is switched to the parking range P or neutral range N, the oil discharged from the oil pump 38 flows into ports 2, 3 and port 20 from the oil path 7. and input the discharge pressure. When the discharge pressure from the oil pump 38 increases, a force is exerted to lower the spool 42 due to the area difference between the lands 42a and 42b, which overcomes the biasing pressure of the spring 39 and moves the spool 42 toward the left half of FIG. Lower it to the position shown. If the spool 42 descends any further, ports 4 and 3 will communicate with each other, reducing the discharge pressure.
Spool 42 tries to rise again. Therefore, a balanced state is reached at the position, and the discharge pressure settles down to a predetermined value. The discharge pressure at this time is the line pressure L in the parking range P or neutral range N. Manual valve 37 is in driving range D, 1, 2
When switched to , the manual valve 37 causes one or both of the front clutch 49 and the rear clutch 50 to transmit torque from an input shaft (not shown) connected to the torque converter 40 to an output shaft (not shown). Line pressure L ₂ is output from port 61 as a signal for travel ranges D, 1, and 2. At this time, as shown in Attachment 1,

【table】

[Table] Line pressure is also applied to port 1 of pressure regulator valve 31 as a signal for travel ranges D, 1, and 2.
L ₂ is connected to port 6 of manual valve 37 at the same time.
It is input from 1. Additionally, as the vehicle speed increases, throttle pressure is also input to port 18, but this is because if throttle pressure is input only to port 16, the force with which spool 41 attempts to raise spool 42 becomes too large. This is to prevent such situations. The line pressure _L2 input to port 1 exerts a force that tends to lift spool 41 due to the difference in area between lands 41c and 41d. Therefore, in order to maintain the spool 42 in the balanced position, the discharge pressure from the oil pump 38 input to the port 20 (i.e., line pressure L ₂ ) is required.
must overcome the biasing pressure of spring 39 and the throttle pressure input to port 16 as well as the line pressure _L2 input to port 1. Therefore, the discharge pressure is greater than the line pressure _L1 in the parking range P or neutral range N. The discharge pressure at this time is the line pressure _L2 in the driving ranges D, 1, and 2. When the manual valve 37 is switched to the reverse range R, the manual valve 37 sends line pressure to the front clutch 49 as a signal for the reverse range R.
Output L ₃ from port 56. In the reverse range R, a very large torque at low engine speeds must be transmitted by only one rear clutch 50, which requires a very large engagement pressure. At this time, as shown in Attachment 1, the line pressure _L3 as a signal of the reverse range R is simultaneously input to port 6 of the pressure regulator valve 31 from the port 56 of the manual valve 37. The line pressure _L3 input to the port 6 exerts a force that tends to raise the spool 41 due to the difference in area between the land 41b and the land 41c.
Since the area difference between the land 41b and the land 41c is larger than the area difference between the land 41c and the land 41d, the lifting force of the spool 41 due to the line pressure _L3 is equal to the lifting force of the spool 41 due to the line pressure _L2 . Greater than force. Therefore, in order for the spool 42 to be maintained at the balanced position, the discharge pressure from the oil pump 38 (i.e., line pressure L ₃ ) input to the port 20 must be input to the urging pressure of the spring 39 and the port 16. In addition to the throttle pressure, the line pressure _L3 input to port 6 must also be overcome. Therefore, considering the difference in the lifting force, the discharge pressure is within the travel range D,
It is larger than the line pressure L ₂ in 1 and 2, that is, it is the largest among the various ranges. The discharge pressure at this time is the line pressure _L3 in the reverse range R. Various ranges R, D, 1, 2,
The line pressure characteristics at P and N are shown in FIG. As explained above, according to this embodiment, the line pressure L ₁ when no signal from the reverse range R or travel ranges D, 1, or 2 is input to the pressure regulator valve 31 is set to Since the line pressure can be lower than the line pressure _L2 or _L3 when the range R or driving range D, 1, or 2 signal is input, fuel efficiency can be improved and starting performance at low temperatures can be improved. improve the
It is possible to prevent abnormal noise from being generated from the oil pump 38 during warm-up. Note that the signal outputted from the manual valve 37 and inputted to the pressure regulator valve 31 may be electrical, and the signal output from the spool 41 of the pressure regulator valve 31 by a solenoid or the like may be used.
The line pressure may be adjusted by assisting the movement of the line. Furthermore, the pressure fluid that generates line pressure etc. is not limited to oil, and may be any other fluid as long as it is incompressible and suitable for transmitting pressure, as long as it does not impede the purpose of the present invention. good.

[Brief explanation of drawings]

Fig. 1 is a hydraulic circuit diagram of a conventional hydraulic pressure control device for an automatic transmission, Fig. 2 is an enlarged sectional view of the pressure regulator valve 31 shown in Fig. 1, and Fig. 3 is an automatic transmission according to the present invention. A hydraulic circuit diagram showing one embodiment of a hydraulic pressure control device for a transmission, Fig. 4 is an enlarged sectional view of the pressure regulator valve 31 shown in Fig. 3, and Fig. 5 shows line pressures corresponding to various ranges. It is a graph showing characteristics. 1... Port (second port), 6... Port (first port), 31... Pressure regulator valve, 37... Manual valve, 39...
Spring (biasing member), 41...Spool (biasing member), 42...Spool, 49...Front clutch, 50...Rear clutch, _L1 , _L2 , _L3
...Line pressure, R...Reverse range, D, 1, 2...
...Driving range.

Claims (1)

[Scope of utility model registration request] There is a manual valve that can output a reverse range or travel range signal to one or both of the front clutch and rear clutch, and the signal output from this manual valve is input to control the line pressure of the fluid discharged from the oil pump between the spool and the fluid. A pressure regulator valve that can be adjusted by a biasing member that biases the spool to the pressure increasing side, wherein the pressure regulator valve The valve is provided with two ports for inputting signals from the manual valve, a first port is provided with hydraulic pressure when the manual valve is in the reverse range, and a second port is provided when the manual valve is in the travel range.
Hydraulic pressure of an automatic transmission characterized in that hydraulic pressure is supplied to a port of the automatic transmission, and the biasing force of the biasing member is increased in accordance with the hydraulic pressure supplied to either the first port or the second port. Control device.