JPH0541863B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a hydraulic control device for an automatic transmission for an automobile, particularly an electronically controlled automatic transmission. (Prior art) By connecting a speed change gear mechanism to the engine output shaft via a torque converter and switching the power transmission path of the speed change gear mechanism, the optimum gear position can be obtained depending on the motion state of the vehicle and manual operation. The automatic transmission, particularly the electronically controlled automatic transmission, includes a plurality of friction elements for switching the power transmission path of the transmission gear mechanism, and a hydraulic actuator for operating these friction elements, as a transmission control means.
A hydraulic control circuit including a plurality of shift valves that supply and discharge hydraulic pressure to and from the actuator, and a plurality of electromagnetic means that actuate each of the shift valves to switch hydraulic pressure supply passages are provided. By switching the shift valve according to the operating state by this electromagnetic means, the hydraulic pressure supply state to each hydraulic actuator or the operating state of each friction element is switched, and accordingly, the power of the transmission gear mechanism is changed. The transmission path, that is, the gear position, is changed. However, in the past, as shift valves in the hydraulic control circuit, for example, in the case of four forward speeds, a 1-2 shift valve, a 2-3 shift valve,
3-4 shift valves are provided, and three solenoids are provided as electromagnetic means for operating each of these shift valves, and when all of the first to third solenoids are inactive, the first solenoid is set to 1st gear. Shift control was performed in such a way that if the solenoid operated, it would be 2nd gear, if the first and second solenoids were activated, it would be 3rd gear, and if all the first to third solenoids were activated, it would be 4th gear. However, according to such a control method, three shift valves and three solenoids are required for four forward speeds. On the other hand, for example, according to Japanese Patent Publication No. 52-46590, four shift valves and two solenoids respectively provided on the shift valves
An automatic transmission is shown with two forward gears available. This is designed to switch the state of the shift valve or the state of the hydraulic pressure supply passage in four ways according to a total of four combinations of activation and deactivation of two solenoids. Also, the number of solenoids is smaller than before, and the configuration is simplified. On the other hand, the hydraulic control circuit is equipped with a manual valve that is manually operated in addition to the shift valve, and the valve controls, for example, the "D" range,
Forward range such as "2" range, "1" range, or "P" (parking) range, "R" (reverse) range,
The "N" (neutral) range etc. can be selected. Regarding each forward range, for example, in the "D" range, shifting is performed in the entire range of 1st to 4th speeds, in the "2" range, shifting is performed in the range of 1st to 3rd speeds, and in the "1" range. In this case, the gears are set to be changed in the range of 1st to 2nd speed.
To set the shifting range according to each range,
In this example, this is done by restricting shifting to 4th gear in the "2" range, and restricting shifting to 3rd and 4th gears in the "1" range. The speed range was limited by electrical control of each solenoid.
However, with the method of setting the shift range for each range by electrically limiting the operation of the solenoid, especially in the case of the above-mentioned configuration in which four forward gears are obtained with two solenoids, The shifting range may be disrupted due to malfunctions such as solenoid shot or disconnection, or abnormalities in the electrical control circuit.
For example, there may be a case where the gear is shifted to the 4th speed in the "2" range, and safety is impaired due to the incorrect shift, especially to the high gear side. (Object of the Invention) The present invention relates to an automatic transmission, in particular to the actuation of two electromagnetic means or two shift valves.
It has a "D" range that can obtain four forward gears and uses all four gears, and a "2" range and a "1" range that sequentially limit the highest used gear to lower gears. In automatic transmission,
The speed change range corresponding to the above "2" range and "1" range is limited without controlling the electromagnetic means.
The range is selected mechanically or hydraulically by operating a manual valve. As a result, if the manual valve is shifted to the "2" range, shifting to 4th gear or 3rd or 4th gear is prohibited regardless of the state of the electromagnetic means, and if the manual valve is shifted to the "1" range, shifting to 3rd or 4th gear is prohibited. Shifting to 4th gear or 2nd, 3rd, or 4th gear is prohibited to prevent erroneous shifting to a higher gear beyond the shifting range set for each range. The purpose is to ensure safety in the event of a failure of electromagnetic means, etc., and to improve the reliability of this type of automatic transmission. (Structure of the Invention) A hydraulic control device for an automatic transmission according to the present invention is characterized in that it is configured as follows to achieve the above object. In other words, as multiple ranges with different speed change ranges,
In an automatic transmission having a "D" range having four forward gears from 1st to 4th gear, and a "2" range and a "1" range in which the highest used gear is sequentially limited to a lower gear, each of the above A manual valve that manually selects the range, a plurality of hydraulic actuators that operate multiple friction elements to switch the power transmission path of the speed change gear mechanism, and four hydraulic actuators that change the hydraulic pressure supply path to these actuators. Two shift valves that obtain forward gears,
These two shift valves are each provided and operated,
4 of these shift valves by non-actuating combination
and two electromagnetic means for switching to the normal state, as well as supplying and discharging hydraulic oil to a hydraulic actuator that operates at the highest gear and other lower gears among the hydraulic supply passages leading to the shift valve. in order to be able to control sequentially by operating the manual valve, the manual valve is formed with first and second ports that are sequentially controlled to open and close in response to the conversion operations to the two ranges and the first range, The first,
By supplying and discharging hydraulic oil by sequentially controlling the opening and closing of the second port, the use of the hydraulic actuator for high gears is sequentially disabled in accordance with the operation to the 2nd range and 1st range. The gear shift range in one range is configured to be limited to a predetermined range. According to such a configuration, regardless of whether the electromagnetic means is activated or not, or in other words, irrespective of a failure of the electromagnetic means, the highest used gear in the "2" and "1" ranges can be mechanically operated by hydraulic pressure. As a result, an erroneous shift to a higher gear in the "2" and "1" ranges is reliably prohibited. (Example) Hereinafter, an example of the present invention will be described based on the drawings. As shown in FIG. 1, the automatic transmission 1 includes a torque converter 10, a multi-speed gear mechanism 20, and an overdrive gear mechanism 40 disposed between the two. The torque converter 10 includes a drive plate 1
1 and the output shaft 3 of the engine 2 via the case 12
The turbine 14 includes a pump 13 directly connected to the turbine 13, a turbine 14 disposed opposite the pump 13 in the case 12, and a stator 15 disposed between the pump 13 and the turbine 14.
4 is coupled to an output shaft 16. Further, a lock-up clutch 17 is provided between the output shaft 16 and the case 12. This lock-up clutch 17 is constantly pressed in the fastening direction by the pressure of the hydraulic oil circulating within the torque converter 10, and is released when release hydraulic pressure is supplied from the outside. The multi-speed gear mechanism 20 has a front planetary gear mechanism 21 and a rear planetary gear mechanism 22, and sun gears 23 and 24 in both mechanisms 21 and 22 are connected by a connecting shaft 25. The input shaft 26 to this multi-speed gear mechanism 20 is connected to the front clutch 2
7 to the connecting shaft 25 and to the ring gear 29 of the front planetary gear mechanism 21 through the rear clutch 28, and the connecting shaft 25, that is, both planetary gear mechanisms 21 and 22
Sun gears 23, 24 and transmission case 30 in
A second brake 31 is provided between the two. Further, the pinion carrier 32 of the front planetary gear mechanism 21 and the ring gear 33 of the rear planetary gear mechanism 22 are connected to the output shaft 34, and furthermore, the pinion carrier 35 of the rear planetary gear mechanism 22 and the transmission case 30 are connected to each other. A low reverse brake 36 and a one-way clutch 37 are respectively provided. On the other hand, in the overdrive transmission gear mechanism 40, a pinion carrier 41 is connected to the output shaft 16 of the torque converter 10, and a sun gear 42 and a ring gear 43 are connected by a direct coupling clutch 44. . Further, an overdrive brake 45 is provided between the sun gear 42 and the transmission case 30, and the ring gear 43 is connected to the input shaft 26 to the multi-speed gear mechanism 20. Thereby, the overdrive transmission gear mechanism 40 directly connects the output shaft 16 of the torque converter 10 and the input shaft 26 to the multi-stage transmission gear mechanism 20 when the clutch 44 is engaged and the brake 45 is released. When the clutch 44 is released and the brake 45 is engaged, the shafts 16, 26 are coupled in overdrive. With the speed change gear mechanism 20, 40 as described above,
This automatic transmission 1 includes the front clutch 2
7, rear clutch 28, second brake 31,
Depending on the selective operation of the lorry berth brake 36, one-way clutch 37, direct coupling clutch 44, and overdrive brake 45, four forward speeds and one reverse speed can be obtained. Table 1 below summarizes the relationships between the operating states of the clutches and brakes and the gear positions. Regarding the first speed, there is a first speed in which the low reverse brake 36 is engaged and the engine brake is effective, and a first speed in which the one-way clutch 37 is activated and the engine brake is not effective.

[Table] Next, the hydraulic control circuit in this automatic transmission 1 will be explained. This hydraulic control circuit includes, as main components, an oil pump 50 that is constantly driven by the output shaft 3 of the engine 2, and a regulator that adjusts the hydraulic pressure generated in the main line 100 by the pump 50 to a predetermined value. A valve 60 and a manual valve 70 whose range is selected by manual operation.
and first and second shift valves 80 and 90. Further, the first and second shift valves 80 and 90 have first and second solenoids 81 and 90, respectively.
91 is provided, and these solenoids 81, 91
The first and second control lines 1 are in the ON state shown in the figure.
By draining 01 and 102, the first
If the second shift valves 80 and 90 are positioned on the right side by springs 82 and 92 as shown in the figure, and the solenoids 81 and 91 are turned off, the first and second shift valves
By closing the drain portions of the control lines 101 and 102, the first and second shift valves 80 and 9
0 moves to the left in the drawing against the springs 82 and 92, respectively. On the other hand, the manual valve 70 can be set to "P", "R", "N", "D", or "2" depending on its operating position.
,
The input port 76 has each range of "1" and is connected to the main line 100, and the first to fifth output ports 71 to 71 are selectively communicated with the main line 100 according to the range of the valve 70.
75 are provided. Among these output ports 71 to 75, the first output port 71 is connected to the manual valve 70.
When in the forward ranges "D", "2", and "1", the actuator 28a of the rear clutch 28 is connected to the main line 100 via the line 103.
Supply operating pressure to. Therefore, “D”, “2”, “1”
In the range, the rear clutch 28 is always engaged. Further, first and second control lines 101 and 102 for operating the first and second shift valves 80 and 90 are branched from the line 103, and therefore, "D", "2", "1" ” range, the first and second shift valves 80, 9
0 is ON of the first and second solenoids 81, 91,
It will be activated depending on the OFF state. Further, a line 100 is branched from a line 103 connected to the first output port 71 to the first shift valve 80, and this line 104 is connected to the line 1 when the first shift valve 80 is in the illustrated position.
05, and further to a line 106 when the second shift valve 90 moves to the left, supplying operating pressure to the actuator 31a of the second brake 31. Therefore, in each range of "D", "2", and "1", the first and second shift valves 80, 9
0 is located on the right and left side of the drawing, respectively (first,
When the second solenoids 81 and 91 are ON and OFF, respectively), the second brake 31 is engaged. Next, the second output port 72 of the manual valve 70 is connected to the main line 100 when the valve 70 is in the "D" or "2" range, and the line 10 connects to the main line 100 and the first shift valve 80.
7. This line 107 is connected to the line 108 when the first shift valve 80 moves to the left.
The actuator 27a of the front clutch 27 is supplied with operating pressure. Therefore,
In the “D” and “2” ranges, when the first shift valve 80 is located on the left side (the first solenoid 81 is
OFF), the front clutch 27 is engaged. In this case, the second output port 72
Since the line 107 is cut off from the main line 100 by the manual valve 70 in the "1" range, the front clutch 27 is not engaged in the "1" range. Further, the third output port 73 of the manual valve 70 indicates that the valve 70 is "P", "R", "2",
When in the "1" range, it communicates with the main line 100, and communicates the line 100 with a line 109 leading to the first shift valve 80. this line 1
09 connects to the line 110 when the first shift valve 80 moves to the left, and also connects to the line 111 when the second shift valve 90 moves to the left.
Leads to. The actuator 44 of the direct coupling clutch 44 is branched into lines 112 and 113.
a and the release side port 45a' of the actuator 45a of the overdrive brake 45. Working pressure is constantly introduced into the actuator 45a engagement side port 45a'' by a line 114 branched from the main line 100, and the overdrive brake 45 is engaged when no operating pressure is introduced into the release side port 45a'. However, as described above, when the operating pressure is also supplied from the lines 111 and 113 to the release side port 45a', the overdrive brake 45 is released.Therefore, in the "2" and "1" ranges, the first and second When shift valves 80 and 90 are both located on the left side (in "P" and "R" ranges, shift valves 80 and 90
does not move to the left), the overdrive brake 45 is released, and at this time the direct coupling clutch 44 is engaged. By the way, the line 11 is connected to the actuator 44a of the direct coupling clutch 44 and the release side port 45a' of the overdrive brake actuator 45a.
Line 11 supplying working pressure via 2,113
1 communicates with the main line 100 via line 115 when the second shift valve 90 is located on the right side as shown in the figure, and even when the second shift valve 90 is located on the left side, the first shift valve 90 is connected to the main line 100 through the line 115. valve 80
When it is located on the right side, it communicates with the main line 100 via the line 110 and line 116 mentioned above. Therefore, the first and second shift valves 80, 9
0 are both on the left side, operating pressure is introduced into the line 111, the direct coupling clutch 44 is tightened, and the overdrive brake 45 is released. When both shift valves 80 and 90 are positioned on the left side, the introduction of operating pressure to line 111 is cut off, direct coupling clutch 44 is released, and overdrive brake 45 is engaged.
However, this only applies to the "D" range, and in the "2" and "1" ranges, operating pressure is introduced into the line 109 from the third output port 73 of the manual valve 70 as described above. , even if both the first and second shift valves 80 and 90 are located on the left side, the line 109 to the line 110,
Actuating pressure is introduced via 111 to engage direct coupling clutch 44 and release overdrive brake 45. Further, the fourth output port 74 of the manual valve 70 is set to "P", "R", and "1".
Connects to main line 100 when in microwave,
The line 100 and a line 117 leading to the second shift valve 90 are communicated. This line 117
When the shift valve 90 is located on the right side as shown, the line 118 is further connected to supply operating pressure to the actuator 36a of the low reverse brake 36.
supply to. As a result, the low reverse brake 36 is engaged in the "P", "R", and "1" ranges. Further, the fifth output port 75 of the manual valve 70 communicates with the main line 100 to connect the line 100 and the line 119 when the valve 70 is in the "R" range. This line 119
are branched into lines 120 and 121 to supply operating pressure to the ends of the first and second shift valves 80 and 90 provided with springs 82 and 92, respectively. , the second shift valves 80, 90 are energized to fix them in the right position shown in the figure. In this state, a line 122 branched from the line 119 and leading to the first shift valve 80 communicates with the line 108 leading to the actuator 27a of the front clutch 27. Therefore, the front clutch 27 is engaged in the "R" range. In the above manner, the manual valve 70
and the first and second solenoids 81 and 91 in the "D", "2", and "1" ranges.
First and second shift valves 80 for ON and OFF,
Depending on the position of 90, the front clutch 2
7, rear clutch 28, second brake 31,
The low reverse brake 36, the direct coupling clutch 41, and the overdrive brake 45 are selectively operated, thereby obtaining a predetermined gear stage, as shown in Table 2. Here, the overdrive brake (OD brake) 45 is designed to be engaged only when the "D" range is 4th speed (marked with ☆ in the table).
Working pressure is supplied only to the engagement side port 45a'' of 5a, and in other cases, both the engagement side and release side ports 45
This is because the working pressure is supplied to a″ and 45′. Also, in the “1” range 1st speed (marked with * in the table),
Since the low reverse brake 36 is engaged, the engine brake is applied to 1st gear, and the other 1st gear is operated by the one-way clutch 3 instead of the low-rise brake 36.
7 is activated, so the engine brake does not work 1
Becomes faster.

[Table] However, in this automatic transmission 1, as shown in Table 2, the entire shift range from 1st to 4th gear is utilized only in the "D" range, and only in the "2" range. In the ``1'' range, the gears are changed only within the range of 1st to 3rd speeds, and in the ``1'' range, the gears are changed only within the range of 1st to 2nd speeds. That is, in the "2" range, shifting to 4th speed is prohibited, and in the "1" range, shifting to 3rd and 4th speeds is prohibited. Here, the control action of the shift range in the "2" and "1" ranges will be explained again using the drawings from FIG. 2 onwards. First, in the "D" range, the first and second solenoids 81 and 91 are turned OFF and OFF.
When the second shift valves 80 and 90 are both located on the left side, the fourth gear is set. In the "2" range, as shown in FIG. is closed in the “D” range) is open and line 1
Since the working pressure is introduced into 09, the above-mentioned first and second
When the solenoids 81 and 91 are turned OFF and OFF and the first and second shift valves 80 and 90 are both located on the left side, the line 109 to the line 110 is
Actuation pressure is introduced into line 111 via lines 112 and 113, and direct coupling clutch 44 is introduced via lines 112 and 113.
Actuating pressure is supplied to the release side port 45a' of the actuator 44a of the overdrive brake 45 and the actuator 45a of the overdrive brake 45, and the direct coupling clutch 4
4 is engaged and the overdrive brake 45
is released. In other words, even if the solenoids 81, 91 or the shift valves 80, 90 are in the fourth gear in the "D" range, they are prevented from shifting into the fourth gear in the "2" range. In this case, the operating pressure is introduced from the second output port 72 to the actuator 27a of the front clutch 27 via the line 107, the first shift valve 80, and the line 108, so that the gear position is set to the third gear. . In addition, in the "1" range, the first and second solenoids 81 and 91 are OFF, as shown in FIG.
OFF, when both the first and second shift valves 80 and 90 are located on the left side, that is, in the “D” range, the
When the gear shifts to the fourth gear, the third output port 73 opens, the direct coupling clutch 44 is engaged, and the overdrive brake 45 is released, as in the case of the "2" range, thereby preventing a shift to the fourth gear. At this time, the line 117 into which the operating pressure is introduced from the fourth output port 74 is cut off from the line 118 leading to the actuator 36a of the low reverse brake 36 by the second shift valve 80.
The gears are the above-mentioned direct clutch 44 and rear clutch 2.
8 and one-way clutch 37, the engine is in first gear in which the engine brake is not effective. Further, as shown in FIG. 4, in the "1" range, the first and second solenoids 81 are in the OFF and ON states, and the first shift valve 80 is located on the left side and the second shift valve 90 is located on the right side. In other words, when the front clutch 27 is engaged in the "D" and "2" ranges and the third gear is set, in the "1" range, the actuator 27a of the front clutch 27 is engaged.
The second output port 72, which supplies operating pressure to the
is prevented from entering into a contract. At this time, operating pressure is supplied from the fourth output port 74 to the actuator 36a of the low reverse brake 36 via the line 117, the second shift valve 90, and the second line 118, so that the gear position is set to 1 where the engine brake is effective. Becomes faster. In this way, the third valve of the manual valve 70
By opening the output port 73 in the "2" and "1" ranges and closing the second output port 72 in the "1" range, shifting to 4th speed is prohibited in the "2" range, and in the "1" range. Shifting to 3rd or 4th gear is prohibited. This can be summarized as shown in Table 3.

[Table] In this embodiment, by opening the fifth output port 75 of the manual valve 70 in the "R" range, the first and second shift valves 80, 90 are connected via the lines 119, 120, 121. An operating pressure is supplied to one end to press and fix the valves 80, 90 in the right-hand position with springs 82, 92, respectively. Therefore, these valves 80 and 90 are stuck or the spring 8
Even if a problem occurs such as a decrease in the pressing force of the shift valves 80 and 92, both shift valves 80 and 90 will be reliably fixed at the right position when the manual valve 70 is shifted to the "R" range. This results in
Even when the above-mentioned malfunction occurs, the reverse gear position can be reliably obtained. In addition, in this embodiment, as shown in FIG. 1, in addition to the above configuration, a lock-up valve 1
30 and a third solenoid 131 for controlling the valve 130. This lock-up valve 130 has a third solenoid 131 as shown in the figure.
By connecting the third control line 132 to the drain part in the ON state, the spring 133 causes the main line 1 to be positioned downward as shown in the figure.
00 through the regulator valve 60 and a line 135 leading to the lock-up clutch 17. Therefore, in this state, the lock-up crank 17 is tightened by the pressure of the hydraulic oil within the torque converter 10. Then, when the third solenoid 131 is turned off, the pressure in the third control line 132 increases, so that the valve 130 is moved upward, causing the lines 134 and 135 to communicate with each other.
This causes the lock-up clutch 17 to be released. (Effects of the Invention) As described above, according to the present invention, the manual valve sequentially limits the "D" range in which all four forward gears are used and the highest gear to be used to the lower gears. In an electronically controlled automatic transmission in which "2" range and "1" range are selected,
The shift range in each range is limited not by controlling the electromagnetic means, but by mechanically or hydraulically disabling the use of the higher gears sequentially by operating the manual valve. Even when a failure occurs in the electromagnetic means, the shift range set for each range is prevented from being disturbed. This reliably prevents erroneous shifting to higher gears, such as shifting to 4th gear in the "2" range, or shifting to 3rd or 4th gear in the "1" range, and this type of automatic The safety and reliability of the transmission will be improved. In particular, the present invention has the advantage that the above effects can be achieved extremely simply.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Fig. 1 is a system diagram showing the mechanical structure and hydraulic control circuit of an automatic transmission, and Figs. 2 to 4 are enlarged views of the main parts of the hydraulic control circuit showing the operating states. It is a diagram. 1... Automatic transmission, 3... Engine output shaft, 2
0, 40... Speed change gear mechanism, 27, 28, 31,
36, 44, 45...Friction element, 27a, 28
a, 31a, 36a, 44a, 45a...hydraulic actuator, 70...manual valve, 7
2, 73... Port, 80, 90... Shift valve, 81, 91... Electromagnetic means.

Claims (1)

[Scope of Claims] 1. A plurality of ranges with different shift ranges include a D range having four forward gears from 1st to 4th gear, and 2 ranges in which the highest used gear is sequentially limited to a lower gear. An automatic transmission having a range includes a manual valve 70 that manually selects each range, and a plurality of manual valves 70 that individually operate a plurality of friction elements to switch the power transmission path of a speed change gear mechanism connected to the output shaft of the engine. Hydraulic actuator 27a, 28
a, 31a, 36a, 44a, 45a, and the hydraulic pressure supply passage to these actuators.
Two shift valves 80 and 90 are provided for each of these two shift valves to obtain four forward gears by switching normally, and these shift valves can be put into four states by combinations of activation and deactivation. It is equipped with two electromagnetic means 81 and 91 for switching and controlling, and among the hydraulic pressure supply passages leading to the shift valve,
In order to be able to sequentially control the supply and discharge of hydraulic oil to the hydraulic actuator operating at the highest gear and other gears lower than this by operating the manual valve, the manual valve is equipped with the two ranges and the first gear.
First and second ports 73 and 72 are formed which are sequentially controlled to open and close in response to the conversion operation to a range, and hydraulic oil is supplied and discharged by sequentially controlling the first and second ports to open and close. By sequentially disabling the use of the hydraulic actuator for high gears in accordance with the operation to the 2nd and 1st ranges, the shift range in the 2nd and 1st ranges is maintained regardless of whether the electromagnetic means is activated or not. A hydraulic control device for an automatic transmission, characterized in that the hydraulic pressure is limited to a predetermined range.