JP2818825B2 - Line pressure control device for automatic transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a line pressure control device for an automatic transmission, and more particularly to a control for controlling a line pressure of a hydraulic control circuit of an automatic transmission when starting in two ranges. Related to the device.

(Prior Art) Generally, when a vehicle starts on a sloping road on a snowy road or the like, if the vehicle starts at a low speed (first speed), the output torque becomes excessively large, and the vehicle may slip. Therefore, it is desirable to start on a sloping road on a snowy road or the like at a high speed (second speed). In an automatic transmission, a manual valve is shifted to two ranges to start.

However, when the vehicle equipped with the automatic transmission starts in two ranges, the torque ratio in the stalled state of the torque converter increases, and accordingly, the friction engagement element constituting the second range of the automatic transmission in the second range. Also, it is necessary to increase the engaging force as compared with the second speed in the case of normal automatic shifting (for example, D range).

As a control device for increasing the engagement force of the friction engagement element in response to the increase in the torque ratio of the torque converter at the time of starting in such two ranges, Japanese Patent Application Laid-Open No. 59-1831 discloses a conventional control device.
There was one described in No. 56.

This conventional control device is a hydraulic control circuit for the third forward speed as shown in FIG. 3, in which FIG. 1 shows a primary regulator valve, 2 shows a secondary regulator valve, 3 shows an orifice control valve, and 4 shows an orifice control valve. Throttle valve, 5 is manual valve, 6 is 1-2 shift valve, 7
Is a 2-3 shift valve, 8 is a boost valve, 9 is a lock-up relay valve, and 10 is a low coast modulator valve.

The engagement of the friction engagement elements at each shift speed is as shown in Table 1 below.

In this control device, when performing the second speed start in the two ranges on a snowy road or the like, the manual valve 5 is shifted to the second range by operating the shift lever, and the second speed start switch 11 is turned on. As a result, the electronic control unit 12 turns on the solenoid S1 and switches the 1-2 shift valve 6, thereby engaging the clutch C1 and the brake B1 and
Construct a high speed gear.

At the same time, the boost valve 8 is switched due to the shift of the manual valve 5 to the two ranges.
L20-Boost valve 8-Introduced into the boost chamber 1A of the primary regulator valve 1 through the oil passage L30, and by pushing up the plunger 1B, the line pressure is increased and the engagement force of the clutch C1 and the brake B1 is increased. Had become.

(Problems to be Solved by the Invention) However, in the conventional control device as described above, the line pressure at the time of starting the second speed in the two ranges is increased regardless of the load of the engine, and the pressure is increased by the engine load. When the engine load is maximum, the friction engagement element is set to be a constant value that can withstand, so even when the engine load is low, the oil pump must be driven more than necessary to generate extra line pressure, However, there is a disadvantage that the fuel efficiency of the vehicle is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages of the conventional automatic transmission control device. In other words, an object of the present invention is to provide an automatic transmission control device that can increase the line pressure when starting in two ranges to increase the engagement force of the friction engagement element and improve fuel efficiency. I have.

(Means for Achieving the Object) The present invention aims to achieve the above object. The two-range pressure from the manual valve and the throttle pressure from the throttle valve are input to the hydraulic control circuit of the automatic transmission,
A throttle modulator valve that adjusts the two-range pressure by applying a two-range pressure input from a manual valve to the spool in opposition to a spring and a throttle pressure and outputs the same as a throttle modulator pressure; and a throttle from the throttle modulator valve. When the modulator pressure and the throttle pressure from the throttle modulator valve are input, and when only the throttle pressure is input, the throttle pressure is output to the boost chamber of the regulator valve. When the throttle modulator pressure is input from the throttle modulator valve, A change valve that shuts off the throttle pressure and outputs the throttle modulator pressure to a boost chamber of a regulator valve.

(Operation) In the above reference device, when the manual valve is in the D range, no pressure is output to the throttle modulator valve in the two ranges. Therefore, the throttle modulator valve is inoperative, and the throttle modulator pressure is also output to the change valve. do not do.

Therefore, the change valve is. The throttle pressure from the throttle valve is introduced into the boost chamber of the regulator valve, and the regulator valve adjusts the line pressure based on the throttle pressure.

When the manual valve is in two ranges, the two range pressure is input to the throttle modulator valve.

In this throttle modulator valve, the input two-range pressure is adjusted to a pressure corresponding to the spring, and further adjusted to a pressure larger by a force opposing the throttle pressure input from the throttle valve. Therefore, the throttle modulator pressure output to the change valve is always higher than the throttle pressure.

Then, the throttle modulator pressure adjusted by the throttle modulator valve is input to the change valve, and the change valve is switched.

As a result, the regulator valve is in the boost chamber. The throttle modulator pressure is introduced from the throttle modulator valve instead of the throttle pressure, and the line pressure is regulated by the regulator valve based on the throttle modulator pressure.

Therefore, in the two ranges, the regulator valve regulates the line pressure by the throttle modulator pressure higher than the throttle pressure, and a line pressure higher than that in the second speed during normal automatic shifting is generated. Since the engaging force of the constituting frictional engagement element is increased, stall start in two ranges is possible. When the engine load is small, that is, when the throttle pressure is small, the throttle modulator pressure is regulated by the throttle modulator valve so as to be reduced accordingly, and as a result, the line pressure is reduced. It is not driven by the above horsepower.

(Examples) Hereinafter, the present invention will be described in more detail based on examples shown in the drawings.

FIG. 1 shows a hydraulic control circuit of a three-speed forward automatic transmission according to the present invention. In FIG. 1, reference numeral 21 denotes a torque converter, 22 denotes an oil pump, 23 denotes a manual valve, and 2 denotes a manual valve.
4 is a 1-2 shift valve, 25 is a 2-3 shift valve, 26 is a throttle valve, 27 is a primary regulator valve,
28 is a secondary regulator valve, 29 is a B1 servo valve, 30 is a C1 accumulator, 31 is a B1 accumulator, 32 is B
Two control valves, S1 and S2, are solenoid valves.

In this hydraulic control device, the connection of the oil passage L1 from the oil pump 22 to each of the oil passages L2, L3, L4, L5 and L6 by the manual valve 23, the solenoid valves S1, S2, and the clutch
The operations of C1, C2, F and brakes B1, B2 are as shown in Tables 2 and 3 below at each shift position P, R, N, D, 2 of the shift lever.

The above-described third forward speed hydraulic control circuit is already known, for example, from Japanese Patent Application Laid-Open No. 62-228741.

In this embodiment, a throttle modulator valve 40 and a change valve 50 are newly added.

This throttle modulator valve 40 is
A port 40a formed between the pair of lands 40B and 40C of the spool 40A of the forty 40 is connected to the line pressure input port 23 from the oil passage L1 of the manual valve 23 by the oil passage L7.
Port formed between a and the output port 23b to the oil passage L6
Communicated with 23c.

The port 23c of the manual valve 23 is closed by a spool land 23A in the D range as shown in the figure, and is opened in the 2 range to communicate with the line pressure input port 23a.

A port 40b formed at the right end of the throttle modulator valve 40 in the drawing is connected to a throttle pressure output port 26a of the throttle valve 26 via an oil passage L8, and the throttle pressure input from this port 26a is applied to a spring 40D. At the same time, the spool 40A is urged leftward in the drawing. Furthermore, the spool 40 of this valve 40
Port 40c formed between a pair of lands 40B and 40C of A is
An oil passage L9 communicates with the input port 50a at the right end of the change valve 50 in the drawing, and the port 40c is connected to a port 40d formed at the left end of the valve 40 by the oil passage L10.
Is communicated to.

The change valve 50 is located at the input port 50b on the left side of the drawing.
Is connected to the throttle pressure output port of the throttle valve by an oil passage L11.
50c is the primary regulator valve by oil line L12
It is connected to 27 boost rooms 27A. In the change valve 50, the spool 50A is switched by the throttle modulator pressure from the port 50a or the throttle pressure from the port 50b, and connects the output port 50c to the port 50a.
And switch to port 50b for communication.

 Next, the operation of the control device will be described.

When the manual valve 23 is in the D range, the port 23c is closed by the spool land 23A and no hydraulic pressure is output to the throttle modulator valve 40. Therefore, the throttle modulator valve 40 is in an inoperative state. No hydraulic pressure is input.

Therefore, in the change valve 50, the spool 50A is switched to the right position in the drawing (the position shown in the drawing) by the throttle pressure input to the port 50b from the throttle valve 26 via the oil passage L11, and the port 50b communicates with the output port 50c.

As a result, the throttle pressure is introduced into the boost chamber 27A of the primary regulator valve 27 through the oil passage L11, the change valve 50, and the oil passage L12.
The line pressure is adjusted based on the throttle pressure.

When the manual valve 23 is in two ranges, the port 23c of the manual valve 23 is opened to communicate with the line pressure input port 23a.
The range pressure is input to port 40a of throttle modulator valve 40 via oil passage L7.

The port in this throttle modulator valve 40
The two-range pressure input to 40a is adjusted to a pressure opposite to the spring 40D, and further adjusted to a pressure higher than the throttle pressure input from the port 40b. The throttle modulator pressure output to the change valve 50 is always higher than the throttle pressure.

The throttle modulator pressure adjusted by the throttle modulator valve 40 is input to the port 50a of the change valve 50 via the oil passage L9, and the throttle valve is input from the port 50b via the spool 50A by the change valve 50. Opposing pressure. At this time, as described above, since the throttle modulator pressure is always higher than the throttle pressure, the spool 50A is slid to the left in the figure to cut off the communication between the port 50b and the output port 50c. Connect to output port 50c.

As a result, the throttle modulator pressure is introduced from the throttle modulator valve 40 to the boost chamber 27A of the primary regulator valve 27 via the oil passage L9, the change valve 50, and the oil passage L12. , Based on the throttle modulator pressure.

Therefore, in the two ranges, the regulator valve 27 regulates the line pressure by the throttle modulator pressure higher than the throttle pressure, and a line pressure higher than that in the second speed of the normal automatic transmission is generated. Since the engaging force of C1 and brake B1 is increased,
Stall start in the range becomes possible. When the engine load is small, that is, when the throttle pressure is small, the throttle modulator pressure is adjusted by the throttle modulator valve 40 so as to be reduced accordingly. As a result, the line pressure is also reduced. It will not be driven with more horsepower than necessary.

The relationship between the throttle pressure, the throttle modulator pressure, and the line pressure in each range is as shown in FIG.

(Effects of the Invention) As described above, according to the present invention, it is possible to increase the line pressure regulated by the regulator valve corresponding to the two range pressures, and to increase the engagement force of the friction engagement element. Stall start during range can be enabled. And
In these two ranges, the hydraulic pressure for operating the regulator valve is regulated by the throttle pressure, so that the line pressure becomes a pressure corresponding to the engine torque, thereby minimizing the power consumption of the oil pump and improving fuel efficiency. I can do it.

[Brief description of the drawings]

FIG. 1 is a hydraulic control circuit diagram showing an embodiment of the present invention, and FIG.
FIG. 3 is a diagram showing a relationship between hydraulic pressures in the embodiment, and FIG. 3 is a hydraulic control circuit diagram showing a conventional example. 27 …… Primary regulator valve 27A …… Boost chamber 23 …… Manual valve 26 …… Throttle valve 40 …… Throttle modulator valve 50 …… Change valve

Claims (1)

(57) [Claims] A hydraulic control circuit of an automatic transmission receives two ranges of pressure from a manual valve and a throttle pressure from a throttle valve, and applies two ranges of pressure from the manual valve to a spring and a throttle pressure for a spool. A throttle modulator valve that regulates two range pressures and outputs the throttle modulator pressure as a throttle modulator pressure, a throttle modulator pressure from the throttle modulator valve and a throttle pressure from the throttle valve are input, and only the throttle pressure is applied. When the throttle pressure is input, the throttle pressure is output to the boost chamber of the regulator valve, and when the throttle modulator pressure is input from the throttle modulator valve, the throttle pressure is cut off to regulate the throttle modulator pressure. A control device for an automatic transmission, comprising: a change valve that outputs a signal to a boost chamber of a data valve.