JPS61130652A - Line pressure control system of automatic transmission with speed change shock reducer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a line pressure control device for an automatic transmission equipped with a variable shock reduction device FF11.

(Prior art) An automatic transmission can obtain a predetermined gear position by selectively hydraulically operating various friction elements, and by changing the hydraulically operated friction elements, the power transmission path can be switched to other gears. It is possible to change gears.

By the way, during the gear shift, the output rotation speed of the automatic transmission corresponds to the vehicle speed and does not change significantly, but the input rotation speed of the automatic transmission changes greatly as the gear changes. It is inevitable that a shift shock will occur due to the rotational speed difference of 7th gear.

Conventional devices for reducing this shift shock include, for example, the device described in "Mitsubishi Automatic Transmission Maintenance Manual" No. 10305202 published by Mitsubishi Motors Corporation, and the device used in the KM 17 S type automatic transmission manufactured by Mitsubishi Motors Corporation. Something like the one shown in Figure 2 is known.

In FIG. 2, 1 is an oil pump, 2 is a regulator valve, 8 is a friction element for shifting, 4 is a friction element for running,
5 is a manual valve, 6 is a shift valve, 7 is a control valve, 8 is a pressure reducing valve, 9 is a dual inlenoid, 1
0 indicates the controller. The spool 2 is elastically supported in the left half position in the figure by the spring 2a on the regulator valve 2.
b, and the line pressure PL is generated in the circuit 11 without removing the oil supplied from the oil pump 1 through the circuit 11 from the drain boat 20. This line pressure reaches the P spool pressure receiving surface 2d K from the circuit 12, and the spool 2
Press b. When the line pressure reaches a certain value determined by the spring force of the spring 2a, the spool 2b is at the right half position in the figure 9. When the spool 2b further descends due to further increase in line pressure, the circuit 11 moves to the drain boat 2C. When the spool 2b rises due to the decrease in line pressure, the circuit 11 is cut off from the drain boat 20 and the line pressure increases. Therefore, the regulator valve 2 maintains the 2-in pressure P at the above-mentioned constant value, and supplies this to the i-inual valve 5 through the circuit 18 Mf.

The manual pal 7'5fl is manually operated by the manual lever 5a, and in the travel range, the circuit 13 is connected to the circuit 14, and the fin pressure PL is supplied to this circuit.

The line pressure PL is supplied from the circuit 14 to the running friction element 4 to keep it operating, and the automatic transmission is maintained in a state capable of transmitting power so that the vehicle can run.

During this running, the shift valve 6 receives the shift signal pressure P from the circuit 15.
. In response to the condition, the circuit 16? The friction element 8 is disconnected from the circuit 17 and connected to the drain (Drenboe) 8iL to deactivate the friction element 8 during gear shifting, thereby maintaining the automatic transmission in the above-mentioned power transmission state. When the shift valve 6 is in the left half state in the figure, the circuit 16
t-operating oil pressure P at 0 friction loss 3 which is connected to circuit 17 to hydraulically actuate the friction element 3 and perform the corresponding gear change. circuit 14
The line pressure PL1 from PL1 is set as the source pressure, but during the above-mentioned shift, this line pressure is not used as the working pressure of the friction element 3 until then, and the shift shock is reduced by controlling the working pressure as described below.

That is, a control valve 7 is inserted between the circuits 14 and 17, and a solenoid 9 is provided to control the operation of this valve, and a pressure reducing valve 8 in the valve 7 reduces the line pressure to a constant value to a pressure P of +i. It is led through the entire circuit 18.19.

Then, the middle of the circuit [9] is connected to the drain boat 9a via the solenoid 9, and the degree of communication is controlled by duty via the solenoid 9 by the controller 1o.

During the above-mentioned speed change, the controller 10 determines the above-mentioned degree of communication by driving the solenoid 9 at a duty ratio according to the engine throttle opening, and sets the duty pressure pDt- of the value corresponding to the circuit 19 yen. generate. The control valve 7 responds to this solenoid duty pressure PD, and the operating oil pressure P of the friction element 8 is directed from the circuit 7 to the circuit 16.

is expressed differently depending on the throttle opening, for example, as shown by the one-dot chain line in FIG. Incidentally, the output torque of the engine is approximately proportional to the throttle opening, and therefore the working oil pressure Po corresponds to the engine output torque, and the engagement capacity of the friction element 3 operated by the oil pressure Po also corresponds to the engine output torque. can be reduced.

(Problems to be Solved by the Invention) However, in an automatic transmission equipped with such a shift shock reducing device, the regulator valve 2 is used in nine ways to maintain the line pressure PL at a value determined by the spring force of the spring 2a. ,
As shown by the solid line in FIG. 3, the line pressure control characteristic was such that the line pressure PL was kept constant regardless of the throttle opening. The line pressure must be kept sufficiently high to ensure the engagement capacity when the friction element 3.4 is fully engaged, as shown for example by the solid line in FIG. 3.

This results in the line pressure PL being unnecessarily high in the shaded area in Figure 8, which means that the oil pump 1
This means that the driving load becomes extra large. Therefore, in the past, an extra load was applied to the engine driving the oil bonder 1 ton, resulting in a large power loss, which caused a problem of deteriorating the dynamic power injection capacity and fuel efficiency.

(Next means for solving the problem) The present invention solves the above-mentioned problem by lowering the hydraulic pressure of the friction component during operation of the gear shift shock reducing device, and also lowering the line pressure that is the source pressure. It is characterized by the fact that the line pressure can be adjusted by making the regulator pulp respond to the solenoid duty pressure for controlling the hydraulic pressure.

(Function) During gear shifting, the solenoid duty pressure is adjusted to the working oil pressure f of the friction element via the control pulp, thereby reducing gear shifting shock. During this time, the solenoid duty pressure also controls the regulator valve.

In this way, the regulator valve adjusts the line pressure in accordance with the above-mentioned pressure regulation of the working oil pressure, and it is possible to solve the problem of the line pressure becoming unnecessarily high during the gear shift and the driving load of the oil pump becoming excessively large. 0 (Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 shows an embodiment of the line pressure control device of the present invention, in which the same parts as in FIG. 2 are designated by the same reference numerals.

In the present invention, a pressure modifier pulp 20 is added to the circuit shown in FIG. Then, spool 2ob connects port 20C at this limit position)2
0d, and at the reverse limit position shown on the right half)! 0
Connects to the drain boat 20e, and connects the port Zoo t-both ports 20d, 201 at the pressure regulating position shown in the left half of the figure.
Assume that it is exactly cut off from B. The upper end surface of the spool 20b in the figure faces the chamber 20f, and the lower end surface in the figure faces the chamber 20g, and the chamber 20f is connected to the circuit 21 and the L circuit 19, and the chamber 20gt is connected to the circuit 23 with the orifice 22.
The regulator pulp 20 is connected to the chamber 2e at the lower end in the figure. Also, the port 200 of the pressure modifier pulp 20 is connected to @path 28 through the circuit 24, and the port 20d is connected to the circuit 13 through the circuit 25. .

The operation of the above embodiment will now be explained. During gear shifting, the same operation as described above with reference to FIG. 2 is performed, that is, friction! ! Primary 3 working oil pressure P. The controller 1O adjusts the solenoid duty pressure PD in the circuit 19 through the duty control of the solenoid 9 so that the pressure becomes as shown by the one-dot chain line in FIG. 8, thereby reducing the shift shock. During this time, the solenoid duty pressure PD in the circuit 19 is also supplied to the brake shield modifier valve 200 chamber 20f through the circuit 21t, and the spool 20bfc cooperates with the spring 20a to further lower the spool 20bfc from the left half position in the figure. As a result, the line pressure PL from the circuit 25 is supplied into the circuit 24, 23 to generate a modifier pressure PM, which pushes back the spool 20b in the chamber 29g. When the modifier pressure PM reaches a value corresponding to the solenoid duty pressure PD in the chamber 20f, the spool 20b is moved to the left half position in the figure and maintains the modifier pressure PM at this value. The modifier pressure PM thus adjusted is supplied from the circuit 23 to the chamber 2e of the regulator valve 2, and the regulator valve 2 increases the line pressure PL by a value corresponding to the modifier pressure PM.

By the way, the working oil pressure P is indicated by a chain line in FIG.

In order to obtain a special order, controller 1G is equipped with solenoid 9.
As the throttle opening increases, solenoid duty pressure PD increases.
Then, the duty solenoid pressure PD increases as the throttle opening increases (the duty solenoid pressure PD increases as the throttle opening increases). As a result, the regulator valve 2 increases the line pressure PL as the throttle opening increases, and can adjust the line pressure PL in accordance with the custom order shown by the dotted line in FIG.

Note that the solenoid duty pressure PD after the gear shift is operated at the oil pressure P while keeping the control pulp 7 in the limit state shown in the figure.

Since it is necessary to set the value to the same value as the line pressure PL, the output pressure P of the pressure reducing valve 8 is constant. However, the line pressure PL is set to the same maximum value as the conventional setting value (in Fig. 8) due to the highest modifier pressure PMK output by the pressure modifier pulp 20 corresponding to the solenoid duty pressure PD at this time. Ninth, in order to prevent the line pressure from exceeding the value indicated by the solid line, and similarly to prevent the line pressure custom-made pressure regulation upper limit value shown by the dotted line in Fig. 8 from exceeding the set value, the spring of the regulator pulp 2 is It goes without saying that 2a needs to have a smaller spring than in the conventional case. (Effects of the Invention) As described above, the line pressure control device of the present invention reduces the friction gI element 3 by the action of the gear shift shock reducing device. Working oil pressure P
of: While the oil pump is being lowered, the line pressure P is also reduced accordingly, which prevents the driving load of the oil pump from becoming excessively large, and reduces the power performance of the engine that drives it and reduces fuel consumption. can solve the problem of deterioration.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a main part of an automatic transmission equipped with a shift shock reducing device equipped with a line pressure control device of the present invention; FIG. 2 is a circuit diagram of a main part similar to FIG. 1 showing a conventional line pressure control device; FIG. 3 shows 4ei-sexual bacteria, comparing the line pressure % injection by the device of the present invention with the line pressure custom made by the conventional device. 1... Oil pump 2... Regulator valve 3... Friction element during gear shifting 4... Friction element for traveling 5... Manual pulp 6... Shift valve 7... Control valve 8... Pressure reduction Valve 9...Solenoid 1G...
...Controller 20...Brella Sha Modifier Valve 2...Oliice PL...Line Pressure PD...Solenoid Duty Pressure P...Modifier Pressure PO...Friction Element Operation Oil Pressure Input

Claims (1)

[Claims] 1. A friction element that is hydraulically operated by line pressure from a regulator valve to change gears, and when changing gears, the operating hydraulic pressure of the friction element is controlled by a control valve that responds to solenoid duty pressure. In an automatic transmission equipped with a shift shock reducing device that reduces shift shock by adjusting pressure, the line pressure can be adjusted by making the regulator valve respond to the solenoid duty pressure. Line pressure control device for automatic transmission with shock reduction device.