JPH03282047A - Line pressure control device for automatic transmission - Google Patents

Abstract

PURPOSE:To increase engaging force of a frictional engaging element during starting at a second range by providing a throttle modulator valve to regulate a second range pressure inputted from a manual valve to output it as a throttle modulator pressure. CONSTITUTION:When a manual valve 23 is in a second range state, a second range pressure is inputted to a port 40a of a throttle modulator valve 40 through an oil passage L7. The second range pressure is regulated to a pressure equivalent to the force of a spring 40D, and is regulated to a value higher by an amount equivalent to a throttle pressure inputted through the port 40b. Thereby, a throttle modulator pressure outputted through a port 40c to a change valve 50 is always increased to a value higher than a throttle pressure. As a result, a throttle modulator pressure is introduced from the valve 40 to a boost chamber 27A of a primary regulator valve 27, in order, through an oil passage L9, the change valve 50, and an oil passage L12, and regulation of a line pressure by means of the valve 27 is performed based on a throttle modulator pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a line pressure control device for an automatic transmission, and particularly to a control device for controlling the line pressure of a hydraulic control circuit of an automatic transmission when starting in two ranges. Regarding equipment.

(Conventional technology) Generally, when a vehicle starts on a slope on a snowy road, etc.

If the vehicle starts in a low gear (first gear), the output torque becomes excessive, which may cause the vehicle to slip. For this reason,
When starting a vehicle on a slope, such as on a snowy road, it is desirable to start the vehicle in a high speed gear (second gear), and in automatic transmissions, the manual valve is shifted to range 2 to start the vehicle.

However, when a vehicle equipped with an automatic transmission starts in the 2nd range, the torque ratio in the stalled state of the torque converter increases, and correspondingly, the frictional engagement element that constitutes the 2nd range 2nd speed of the automatic transmission increases. Also, it is necessary to increase the engagement force compared to the second speed in the case of normal automatic shifting (for example, D range).

Conventionally, as a control device for increasing the engagement force of the frictional 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. 59-18
There was one described in Publication No. 3158.

This conventional control device is a three-speed forward hydraulic control circuit as shown in Fig. 3, in which 1 is a primary regulator valve, 2 is a secondary regulator valve, 3 is an orifice control valve, and 4 is the throttle valve, 5 is the manual valve, and 6 is the 1-2 shift valve.

7 is the 2-3 shift valve, 8 is the boost valve.

9 is a lock-up relay valve, and 10 is a low coast modulator valve.

The engagement of the frictional engagement elements at each gear stage is as shown in Table 1 below.

Table 1 In this control device, when performing a 2nd speed start in the 2nd range on a snowy road, etc., the manual valve 5 is shifted to the 2nd range by operating the shift lever, and the 2nd speed start switch 11 is turned on. Accordingly, the electronic control unit 12 turns on the solenoid S1 and switches the 1-2 shift valve 6.

Clutch C1 and brake B1 are engaged to configure a second gear.

At the same time, the manual I (lube 5) is shifted to the 2nd range, so the boost valve 8 is switched, and the 2nd range pressure from the manual valve 5 is transferred from oil path L20 to boost no (lube 8 oil path L30). Brying regulator (introduced into the boost chamber IA of Lube 1 and pushing up the plunger IB to increase line pressure and reduce clutch C1 and brake B1)
It was designed to increase the engagement force of the

(Problem to be solved by the invention) However, in the conventional control device as described above, the line pressure at the time of starting in 2nd gear in the 2nd range is increased regardless of the engine load, and the line pressure is increased depending on the engine load. Since the frictional engagement element was set to be constant at a value that it could withstand when the engine load was at its maximum, the oil pump had to be driven more than necessary to generate extra line pressure even when the engine load was low, causing the vehicle to The disadvantage was that it reduced fuel efficiency.

The present invention has been made in order to eliminate the drawbacks of the conventional automatic transmission control device described above. That is, the purpose is to provide a control device for an automatic transmission that can increase the line pressure to increase the engagement force of the frictional engagement element when starting in the second range, and improve fuel efficiency. There is.

(Means for Achieving the Object) In order to achieve the above object, the present invention provides a hydraulic control circuit of an automatic transmission with two range pressures from a manual valve and a throttle pressure from a throttle valve. A throttle modulator valve that adjusts the two range pressure input from the valve by acting on a spool in opposition to a spring and throttle pressure and outputs it as a throttle modulator pressure.

Throttle modulator pressure from this throttle modulator valve and throttle pressure from the throttle modulator valve are input, and when only throttle pressure is input, this throttle pressure is output to the boost chamber of the regulator valve, and the throttle pressure from the throttle modulator valve is input. It is characterized by having a change valve that cuts off the throttle pressure and outputs the throttle modulator pressure to the boost chamber of the regulator valve when the modulator pressure is input.

(Function) In the above cited device, when the manual valve is in the D range, the 2-range pressure is not output to the throttle modulator valve, so the throttle modulator valve is in an inactive state, and the throttle modulator pressure is also output to the change valve. do not.

Therefore, the change valve introduces the throttle pressure from the throttle valve into the boost chamber of the regulator valve, and the regulator valve regulates the line pressure based on this throttle pressure.

When the manual valve is in the 2nd range, the 2nd range pressure is input to the throttle modulator valve.

In this throttle modulator valve.

The input two-range pressure is regulated to a pressure corresponding to the spring, and further regulated to a pressure greater by a force opposing the throttle pressure input from the throttle valve.

Therefore, the throttle modulator pressure output to the change valve is always greater than the throttle pressure.

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

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

Therefore, in these 2 ranges, the regulator valve regulates the line pressure using the throttle modulator pressure, which is higher than the throttle pressure.1 A line pressure higher than that in 2nd gear during normal automatic shifting is generated, and the 2nd gear Since the engagement force of the constituent frictional engagement elements is increased, it is possible to stall and start in two ranges. And this throttle modulator pressure is, when the engine load is small,
That is, when the throttle pressure is small.

The pressure is regulated to be reduced by that amount by the throttle modulator valve, and as a result, the line pressure is also reduced, so the oil pump will not be driven with more horsepower than necessary.

(Example) Hereinafter, the present invention will be described in further detail based on an example shown in nine drawings.

FIG. 1 shows a hydraulic control circuit for a three-speed forward automatic transmission according to the present invention. In FIG. 1, 21 is a torque converter, and 22 is an oil pump.

23 is a manual valve, 24 is a 1-2 shift valve,
25 is a 2-3 shift valve, 26 is a throttle valve,
27 is the primary regulator valve, 28 is the secondary regulator valve, 29 is the B1 servo valve, 30
is the C1 accumulator, 31 is the Bl accumulator,
32 is the B2 control valve.

Sl and B2 are solenoid valves.

In this hydraulic control device, an oil path L1 from the oil pump 22 and each oil path L2 . L3
．． L4. Connections with L5 and L6, and solenoid valve S1. B2. Clutch CI.

The operations of C2, F and brakes B1, B2 are as shown in Tables 2 and 3 below at each shift position IP, R, N, D, and 2 of the shift lever.

(The following is a blank space) Table 2 The hydraulic control circuit for three forward speeds as shown above is already known, for example, from Japanese Patent Laid-Open No. 82-228741.

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

This throttle modulator valve 40 has a port 40g formed to open between a pair of lands 40B and 40C of a spool 40A of this valve 40, which is connected to an oil path L.
7, the line pressure input port 23a from the oil passage L1 of the manual valve 23 and the output port 23 to the oil passage L6
The boat 23C is connected to the boat 23C formed between the

Note that the port 23c of this manual valve 23 is connected to D
As shown in the figure, the range is closed by a spool land 23A, and when the range is 2, it is opened and communicated with the line pressure input boat 23a.

Further, a port 40b formed at the right end of the throttle modulator valve 40 in the figure is communicated with the throttle pressure output port 26a of the throttle valve 26 through the oil passage L8, and the throttle pressure input from the boat 26a is communicated with the throttle pressure output port 26a of the throttle valve 26. Together with the spring 40D, the spool 40A is biased toward the left in the drawing. Furthermore, a pair of lands 40B, 40 of the spool 40A of this valve 40
The boat 40c formed between C is connected to the input port 50a of the change valve 50 on the right end side in the drawing by an oil passage L9, and this port 40c is formed at the left end of the valve 40 in the drawing by an oil passage LIO. It is communicated with port 40d.

The change valve 50 is the input boat Sob on the left end side in drawing 9.
is communicated with the throttle pressure output port of the throttle valve by an oil passage Lll, and the output port 50c in the center is communicated with the boost chamber 27A of the primary regulator valve 27 through an oil passage L12. In this change valve 50, the spool 50A is switched by the throttle modulator pressure from the boat 50a or the throttle pressure from the boat 50b, and the output port 50c is switched to communicate with the port 50a and the boat 50b.

Next, the operation of the above control device will be explained.

When the manual valve 23 is in the D range, the port 23C is closed by the spool land 23A and no oil pressure is output to the throttle modulator valve 40, so the throttle modulator valve 40 is in an inactive state, and the boat 50a of the change valve 50 is in an inactive state. No oil pressure is input.

Therefore, the change valve 50 is the throttle valve 26
The spool 50A is switched to the right position in the drawing (the position shown) by the throttle pressure input to the boat 50b via the oil path Lll, and the port 50b is connected to the output port 50c.
communicate with.

As a result, the throttle pressure is introduced into the boost chamber 27A of the primary regulator valve 27 via the oil passage Lll, the change valve 50, and the oil passage L12, and the regulation of the line pressure by the regulator valve 27 is based on this throttle pressure. This will be done based on the following.

When the manual valve 23 is in the 2nd range, the port 23C of the manual valve 23 is opened and communicated with the line pressure input port 23a.
3c, the two range pressure is input to the port 40a of the throttle modulator valve 40 via the oil path L7.

In this throttle modulator valve 40, the two-range pressure input to the port 40a is regulated to a pressure that opposes the spring 40D, and is further regulated to a pressure that is larger by the amount that opposes the throttle pressure input from the port 40b. . Therefore, the throttle modulator pressure output from the port 40c to the change valve 50 is always greater than the throttle pressure.

Then, the throttle modulator pressure regulated by the throttle modulator valve 40 is input to the port 50g of the change valve 50 via the oil path L9, and in this change valve 50, the pressure is input to the port 50g via the spool 50A.
It is opposed to the throttle pressure input from b. At this time, as mentioned above, since the throttle modulator pressure is always higher than the throttle pressure, the spool 50A is slid to the left in the drawing, and the port 50b and the output port 50
Therefore, the port 50a is communicated with the output port 50c.

As a result, the throttle modulator pressure is introduced into the boost chamber 27A of the primary regulator valve 27 from the throttle modulator valve 40 via the oil passage L9, the change valve 50, and the oil passage LI2, and the line pressure is regulated by the regulator valve 27. is performed based on this throttle modulator pressure.

Therefore, when in these two ranges, regulator valve 2
7. The line pressure is regulated by the throttle modulator pressure, which is higher than the throttle pressure. 1. A line pressure higher than that in the second gear of a normal automatic transmission is generated, and the engagement force of the clutch C1 and the brake B1 is increased. Therefore, it is possible to start from a stall in 2 ranges. Then, when the engine load is small, that is, when the throttle pressure is small, this throttle modulator pressure is regulated to be reduced by that amount by the throttle modulator valve 40, and as a result, the line pressure is also reduced, so that the oil pump 22 is It is never driven with more horsepower than necessary.

Furthermore, the relationship between throttle pressure, throttle modulator pressure, and line pressure in each range is as follows.

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 in response to the 2-range pressure, increase the engagement force of the frictional engagement element, and increase the 2-range pressure. It is possible to start from a stall when using the range. When in these two ranges, the oil pressure that operates the regulator valve is regulated by the throttle pressure, so the line pressure corresponds to the engine torque, which makes it possible to minimize the power consumption of the oil pump and reduce fuel consumption. It can be improved.

[Brief explanation of drawings]

Fig. 1 is a hydraulic control circuit diagram showing one embodiment of the present invention;
This figure is a diagram showing the relationship of appropriate pressures in the same 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)

[Claims] A two-range pressure from a manual valve and a throttle pressure from a throttle valve are input to a hydraulic control circuit of an automatic transmission, and the two-range pressure input from the manual valve is applied to a spool to control a spring and a throttle. A throttle modulator valve regulates two range pressure by acting oppositely on the pressure and outputs it as a throttle modulator pressure.The throttle modulator pressure from this throttle modulator valve and the throttle pressure from the throttle valve are input, and the throttle pressure is When only the throttle pressure from the throttle modulator valve is input, this throttle pressure is output to the boost chamber of the regulator valve, and when the throttle modulator pressure from the throttle modulator valve is input, the throttle pressure is cut off and the throttle modulator pressure is output to the boost chamber of the regulator valve. 1. A control device for an automatic transmission, comprising a change valve.