JPS601443A - Hydraulic controller for automatic speed change gear - Google Patents

Abstract

PURPOSE:To increase the freedom in setting the speed change line without giving an influence onto the speed change shock by correcting the governor pressure according to the opening degree of a throttle and applying said corrected governor pressure onto shift valves. CONSTITUTION:A governor pressure correcting valve 26 in which the set pressure is varied by a cam 44 connected to an acceleration pedal 50 and which adjusts the corrected governor pressure which varies according to the governor pressure corresponding to a car speed and the magnitude of the opening degree of a throttle is installed between a governor valve 24 and shift valves 8 and 10. Therefore, the governor pressure is corrected according to the opening degree of the throttle. Since the corrected governor pressure can be applied onto the shift valves 8 and 10, the freedom in setting the speed change line is increased by a large margin, and a desired speed change line can be set.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a hydraulic control device for an automatic transmission.

(b) Prior art In general, in conventional dynamic transmissions, the engine output is detected as the throat pressure corresponding to the intake pipe negative pressure, and the running speed of the vehicle is detected as the governor pressure. The sleeve pressure is guided to the shift valve, and the gears are changed depending on the magnitude relationship between the sleeve pressures. Furthermore, the line pressure, which is the operating pressure for tightening the friction elements, has been regulated based on the throttle pressure. Since the engine output and intake pipe negative pressure approximately correspond, if the line pressure is adjusted to correspond to the throttle pressure as described above, the transmission torque capacity of the friction element will approximately correspond to the engine output. Regarding the gear shift shock, I am almost satisfied. However, conventional hydraulic control devices such as those described above are not necessarily sufficient in terms of shift lines. In other words, there is no linear relationship between the accelerator opening and the engine intake pipe negative pressure, and in the region where the accelerator opening is small, the intake pipe negative pressure changes greatly in response to changes in the accelerator opening. In the region where the opening degree is large, the intake pipe negative pressure does not change much. For this reason, in areas where the accelerator opening is small, the shift point will change significantly by changing the accelerator opening slightly, but in areas where the accelerator opening is large, the shifting point will hardly change even if the accelerator opening is changed considerably. I will not do it. However, this does not match the driver's preferred feeling. For example, regarding the 2-3 shift of an automatic transmission with 3 forward speeds, if the accelerator opening is small, the driver intends to shift to 3rd gear at a relatively low vehicle speed and drive steadily. In addition, in areas where the accelerator is opened to a large extent for purposes such as overtaking, it is desirable to continue driving in 2nd gear up to a considerably high speed. However, as described above, when throttle pressure obtained by converting engine intake pipe negative pressure into oil pressure is used for shift control, it becomes difficult to obtain such a shift line desired by the driver. For this reason, in conventional hydraulic control devices for automatic transmissions, it is not always possible to ideally set the gear shift line, and a certain degree of compromise has had to be made. In addition, in the case of a turbocharged engine, the negative pressure takes a positive value (i.e.
Therefore, it becomes increasingly difficult to set a preferable shift line based only on the engine's intake pipe negative pressure.

Note that there are other hydraulic control devices for automatic transmissions that directly convert the accelerator opening into throttle pressure without using the engine's intake pipe negative pressure as a reference, but in this case, there is some freedom in setting the shift point. degree increases. However, since the correspondence between the accelerator opening and engine output is lower than the correspondence between intake pipe negative pressure and engine output, the shift control tends to be worse than those using intake pipe negative pressure. be. Therefore, it is necessary to take measures to improve the shift shock, such as providing an accumulator.

(C) Object of the Invention The present invention provides an automatic transmission hydraulic pressure side ial [
The aim is to obtain a l device.

(d) Structure of the invention The present invention corrects the governor pressure according to the throttle opening,
The above problem is solved by applying this corrected oil pressure to the shift valve. That is, the hydraulic control device for an automatic transmission according to the present invention is characterized by having a governor pressure correction valve that regulates a correction governor pressure that changes depending on the governor pressure corresponding to the vehicle speed and the magnitude of the throttle opening.

(e) Examples Examples of the present invention will now be described with reference to FIGS. 1 to 12 of the attached drawings.

(First Embodiment) FIG. 1 shows a schematic diagram of a power transmission mechanism of an automatic transmission with three forward speeds and one reverse speed. This power transmission mechanism includes an input shaft I to which the rotational force from the engine output shaft E is transmitted via the torque converter T/C, an output shaft 0 which transmits the driving force to the final drive device, a first planetary gear set G1. 2nd planetary gear set Gz, front clutch F/C, rear clutch R/
C, band brake B, low and reverse brake L
&R/B, and one-way clutch OWC. The 1'th ML star gear set G1 is composed of a sun gear S1, an internal gear R1, and a carrier PC that supports the pinion gear P1 that meshes with both gears S1 and Rj at the same time, and the planetary gear set GZ is Carrier PCZ that supports sun gear SZ, internal gear R, and pinion gear PZ that meshes with both gears Sz and R at the same time.
It is composed of. The carrier PCI is connected to the output shaft O, and the sun gear S] is the front clutch F/C.
The internal gear R1 can be connected to the input axle load via the rear clutch R/C, and the internal gear R1 can be connected to the human powered shaft (2) via the rear clutch R/C. Internal gear R2 is connected to output shaft O, and sun gear S2 is connected to sun gear Sl. Carrier PC2 is one-way club Nnaowc
It is fixed in one rotational direction by the locking mechanism, and can be fixed in both rotational directions by the low ant reverse brake L&R/B. Band brake B is Sungear S
l and Sz can be fixed. This band brake B is operated by the hydraulic pressure acting on the servo apply chamber S/A and the servo release chamber S/R, which has a larger working area. That is, when hydraulic pressure is applied to the servo apply chamber S/A, the band brake B is engaged, and when hydraulic pressure is applied to the servo release chamber S/R, the servo apply chamber S/A is engaged.
Band brake B is released regardless of the presence or absence of hydraulic pressure. Torque converter T/C is pump impeller PI
, a turbine runner T, and a stator ST. Pump impeller PI is connected to engine output shaft E via torque converter cover PI'. The turbine runner T is connected to the input shaft ■, and the stator ST
is connected to a stationary part via a one-way clutch sowc.

The above power transmission mechanism includes front clutch F/C, rear clutch R/C, band brake B, and low and reverse brake L&R/B (one-way clutch 0WC).
By operating the planetary gear sets G1 and GZ in various combinations, each element (S+, Sz, R, , R2, P
C, and PCz) can be changed, thereby making it possible to variously change the rotational speed of the output shaft 0 relative to the rotational speed of the input shaft I. By operating the clutch and brake in combination as shown in the table below, three forward speeds and one reverse speed can be obtained.

(Left below) In addition, the O mark in the table above indicates the clutch and brake that are in operation. Furthermore, the fact that (OWC) is displayed below L&R/B indicates that the first speed can be obtained by the one web clutch OWC even when the low and reverse brake L&R/B is not operated. However, in the first speed in this case, it is not possible to drive from the output shaft O side (that is, the engine brake is not effective). Also.

At the bottom of the band brake B column is the servo apply chamber S.
This figure shows the state of oil pressure supply to the /AR and servo release chambers S/R.

FIG. 2 shows a hydraulic control device according to the present invention. This hydraulic control device includes an oil pump 2, a pressure regulator valve 4, a manual valve 6.1-2 and a shift valve 8.2.
-3 shift) valve 1o, pressure modifier valve 12, vacuum throttle valve 14, throttle pack amplifier valve 16. Tsure/Ido Town Shift I
- It has a valve 18, a second lock valve 2o, a timing valve 22, a governor valve 24, and a cabana pressure correction valve 26, and these valves are used for the torque converter T/C, front clutch F/C, and rear clutch R.
/C, is connected to the band brake's servo apply chamber S/A, servo release chamber S/R1, and low and reverse brake L&R/B as shown in the diagram, and by the action of these valves, each Hydraulic pressure is distributed to the friction elements. In the following description, the governor pressure correction valve 26, which is directly related to the present invention, will be mainly described in detail, and the description of other valves will be omitted. The structure and operation of the parts whose explanations are omitted are the same as those disclosed in, for example, Japanese Patent Application Laid-open No. 132062/1983.

The cabana pressure correction valve 26 includes a spool hole 32 having bows 32a to 32e, a spool 34 inserted into the spool hole 32, and a slider 36 inserted into the spool 32.
and a spring 38 disposed between the spool 34 and the slider 36. 32a is oil passage 40
It is connected to port 32c via. This oil passage 40
■-2 shift valve 8.2-3 shift/help 10
, pressure modifier valve 12, and timing valve 22. The port 32b is connected to an oil passage 42 to which kapana pressure is supplied from the governor/help 24. Ports 32d and 32e are drain ports. The spool 34 has lands 34a to 34
It has c. Land 34a is connected to lands 34b and 34
It has a diameter larger than c. The slider 36 is pushed against the cam 44 by the force of the spring 38. The cam 44 is rotatable about a pin 46 and is connected to an accelerator pedal 50 by a wire 48. Therefore, when the accelerator pedal 50 is depressed, the cam 44 rotates counterclockwise and the slider 36 moves downward in FIG.

Next, the operation of this embodiment will be explained. In the condition shown in FIG. 2, the spool 34 of the governor pressure correction valve 26 is in equilibrium. That is, the pressure is regulated by discharging a part of the gas pressure supplied from the oil passage 42 to the port 32b from the port 32d. Hydraulic pressure (
The downward force due to the corrected governor pressure (corrected governor pressure) is balanced by the upward force of the spring 38 and the force due to the governor pressure of the port 32b acting on the area difference between lands 34a and lands 34b of the spool 34. This can be expressed as an equation as follows.

SIXPcM=S2XPG+F Sl...Pressure receiving area Sz of land 34a...Difference P between the pressure receiving area of land 34a and the pressure receiving area of land 34b CM...Corrected governor pressure PG...φGovernor pressure F・...Force of the spring 38 Therefore, PCM=(SZ/S+)XPG+F/S 1 By the way, the force F of the spring 38 is determined by the position of the slider 36 (that is, the rotational position of the cam 44). The shape of the cam 44 varies depending on the amount of depression of the accelerator pedal 50 (throttle opening) as shown in FIG.
It is designed so that it can take a value of 2. The relationship between the governor pressure PG and the corrected governor pressure Pct-1 in this case is illustrated in FIG. 4. Note that the corrected governor pressure PGM is regulated using the governor pressure PG as a hydraulic pressure source, so it does not become larger than the governor pressure PG. Therefore, first PGM
is equal to PG, rises along a line with a 45 degree slope, and gradually slopes midway depending on the throttle opening (SZ/S
l). The governor pressure PG has a characteristic as shown in diagram f55 with respect to the rotational speed of the output shaft of the automatic transmission.

FIG. 6 shows the characteristics of the corrected governor pressure PCH with respect to the output shaft rotational speed. The corrected governor pressure PO,I having the characteristics shown in FIG.
-2-2 shift valve 8 and 2-3 shift valve LO are affected. ■-2 shift valve 8 and 2-3 shift valve 1
0, the line pressure or throttle pressure is opposed to this corrected governor pressure P (g), and the change is made depending on the balance of the forces. Therefore, the slope of the shift line in the region where the throttle opening is large can be made gentle (that is, the shifting vehicle speed can be changed largely with respect to a change in the throttle opening). Moreover, the inclination of the shift line at the inflection point of the shift line (that is, the point where the corrected governor pressure PcM begins to become smaller than the governor pressure PG) and the region where the throttle opening is larger than the inflection point is determined by the characteristics of the spring 38. , cam 4
4 and the shape of the spool 34 (ratio of S+ and Sz)
It can be set freely by Therefore, the degree of freedom in setting the shift line is greatly improved, and an ideal shift line that matches the driver's senses can be obtained.

(Second Embodiment) A second embodiment of the present invention is shown in FIG. In this second embodiment, a switching valve 60 is added to the hydraulic control device shown in FIG. This switching valve 60 is connected to an oil passage 62 connected to the bow 32d of the governor pressure correction valve 26, an oil passage 42 which is a governor pressure circuit, and an oil passage 64 which is a line pressure circuit, as shown. . The rest of the configuration is the same as that shown in FIG. With such a configuration, the following effects can be obtained. That is, in the illustrated state in which the oil passage 62 is drained, the state is exactly the same as in the first embodiment, and the same effect as in the first embodiment can be obtained. However, when the governor pressure in the oil passage 42 increases and the spool of the switching valve 60 is switched to the instep side position, the oil passage 62 is no longer drained, so the governor pressure correction valve 26 loses its pressure regulating function, and the governor pressure is supplied. Corrected governor pressure Pc obtained by this second embodiment
The characteristics of M are illustrated in FIG. 8. That is, when the rotational speed exceeds a predetermined speed (predetermined governor pressure), the corrected governor pressure PcN becomes equal to the governor pressure PG. The reason why the change-over valve 6o is provided and the characteristics of the corrected governor pressure P (H) are as follows is that the corrected governor pressure PcM is equal to the cabana pressure PG.
Depending on the configuration of the shift valve, the shift point may become too high in the region where the throttle opening is large. Therefore, at vehicle speeds above a predetermined speed, the corrected governor pressure PGM should be switched to the governor pressure PG to perform gear shifts. This is to make it possible.

(Third Embodiment) FIG. 9 shows a third embodiment of the present invention. This third embodiment is obtained by adding a pressure regulating valve 70 to the first embodiment shown in FIG. The pressure regulating valve 70 is the port of the pressure regulating valve 26)
32b, an oil path 42 which is a governor pressure circuit, and an oil path 62 which is a line pressure circuit, as shown. The configuration other than the above is the same as that shown in FIG. 2. The pressure regulating valve 70 uses line pressure as a hydraulic source, governor pressure PG as a pilot pressure, and regulates an increased governor pressure PC^ having characteristics as shown in FIG. 1O in an oil passage 72. The increased governor pressure PC,A has a value larger than the governor pressure P, as shown in FIG.
(greater than the degree line). The governor pressure correction valve 26 basically performs the same function as in the above case based on the increased governor pressure P (, A, and regulates the corrected governor pressure PG-1. In this case, the increased governor pressure P (, A Since the slope of is larger than that in the first embodiment, the corrected governor pressure P and M have the characteristics as shown in Fig. 11.If this is rewritten in relation to the output shaft rotational speed, Fig. 12 shows. The third embodiment differs from the first embodiment in that the change in the corrected governor pressure PO,I after the inflection point can be made almost equal to the governor pressure PG. , as shown in Fig. 12, it is possible to prevent the corrected governor pressure Pc1.I from becoming significantly larger than the governor pressure PG in the region of large throttle opening.Therefore, the existing shift valve and governor valve can be changed. The shift line can be set to a more preferable state without any problems.

(f) As described in detail, the present invention provides a hydraulic control system for a dynamic transmission that changes gears by sequentially switching the operating states of a plurality of friction elements. Since it has a covering pressure correction valve that regulates the correction governor pressure that changes depending on the magnitude of the opening, the degree of freedom in setting the shift line is greatly increased, and it becomes possible to set the desired shift line.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an automatic transmission, Fig. 2 is a diagram showing a hydraulic control device for an automatic transmission according to a first embodiment of the present invention, and Fig. 3 is a diagram showing the relationship between throttle opening and spring force. line diagram,
Figure 4 is a diagram showing the relationship between governor pressure and corrected governor pressure.
FIG. 5 is a diagram showing the relationship between output shaft rotation speed and governor pressure, FIG. 6 is a diagram showing the relationship between output shaft rotation speed and corrected governor pressure, and FIG. 7 is a diagram showing a second embodiment of the present invention. FIG. 8 is a diagram showing the relationship between the output shaft rotational speed and the corrected governor pressure in the second embodiment, and FIG. 9 is a diagram showing the relationship between the output shaft rotation speed and the corrected governor pressure in the third embodiment of the present invention. A diagram showing a hydraulic control system of a certain automatic transmission, FIG. 10 is a diagram showing the relationship between governor pressure and increased governor pressure, and FIG. 11 is a diagram showing the relationship between governor pressure and corrected governor pressure in the third embodiment. FIG. 12 is a diagram showing the relationship between the rotational speed of the output shaft and the correction gas/hess pressure in the third embodiment. 14・φ・Throttle valve, 24・・Cavanagh valve, 26・・・φGovernor pressure correction valve, 44・φ・Cam, 5
0Φ...Accelerator pedal. Patent Applicant Japan Automatic Transmission Co., Ltd. Agent Patent Attorney Toshiyuki Miyauchi Figure 3 Throttle opening governor pressure ρG Figure S 1't'', figure output shaft rotation far

Claims (1)

[Claims] 1. In a hydraulic control device for an automatic transmission that changes gears by sequentially switching the operating states of a plurality of friction elements, correction that changes according to the governor pressure corresponding to the vehicle speed and the magnitude of the throttle opening A hydraulic control device for an automatic transmission, characterized by having a governor pressure correction valve that regulates governor pressure. 2. The hydraulic control device for an automatic transmission according to claim 1, wherein the governor pressure correction valve adjusts the correction governor pressure that increases as the governor pressure increases and decreases as the throttle opening increases. . 3. The corrective governor pressure is guided to a port of the shift valve that provides a force in a direction that opposes the force exerted on the shift valve by throttle pressure, line pressure, or the corresponding hydraulic pressure. Hydraulic control device for an automatic transmission as described in .