JPS6327171Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of Industrial Application) The present invention relates to an electronically controlled automatic transmission. Automatic transmissions commonly used today are constructed by combining a fluid torque converter and a multi-stage gear type transmission mechanism having a gear mechanism such as a planetary gear mechanism. A hydraulic mechanism is normally used for speed change control of such automatic transmissions, and the hydraulic circuit is switched using a mechanical or electromagnetic switching valve. The engine power transmission system is changed by appropriately varying the elements to obtain the desired gear position. When switching the hydraulic circuit using an electromagnetic switching valve, an electronic device detects when the vehicle's running state exceeds a predetermined shift line, and a signal from this device is used to switch the electromagnetic switching valve. It is common practice to selectively operate the hydraulic circuit and thereby change the speed by switching the hydraulic circuit. Automatic transmissions that utilize hydraulic torque converters have extremely excellent characteristics, and various types have been developed and put into practical use for vehicles. However, in a hydraulic torque converter, the torque conversion ratio is relatively large in a range where the ratio between the turbine rotation speed and the pump rotation speed is small, especially when the turbine runner is stalled, so in conventional automatic transmissions of this type, Even when the engine is operated under no load, there is a problem in that a considerable amount of force is applied to drive the vehicle when the vehicle is stopped or running at low speed. This not only causes the phenomenon of vehicle creep to increase the braking distance, but also increases fuel consumption during no-load operation. For this reason, in conventional vehicles equipped with this type of automatic transmission, when stopping for a short time such as waiting at a traffic light, the driver must keep pressing the brake or operate a lever to shift the transmission to neutral. . This is not preferable in terms of simplifying driving operations, and furthermore, reducing the amount of braking has various disadvantages, such as having an adverse effect on vehicle performance. In order to overcome this drawback, Japanese Patent Publication No. 47-19962 proposes a fluid-type automatic transmission that automatically shifts to neutral when the accelerator is released when the vehicle is stopped or running at low speed. In the transmission, it is necessary to install a dedicated solenoid, which has the disadvantage that the overall structure becomes complicated and the weight becomes large. (Purpose of the invention) Therefore, the present invention is an electronically controlled automatic system that automatically enters the neutral state without the need for a dedicated solenoid when the vehicle is stopped or when the accelerator is released while driving at low speed. The purpose is to provide a transmission. (Structure of the invention) The electronically controlled automatic transmission according to the invention includes a torque converter connected to the output shaft of the engine, a speed change gear mechanism connected to the output shaft of the torque converter, and a power transmission path of the speed change gear mechanism. a plurality of friction elements for switching, a hydraulic actuator for operating these friction elements, a plurality of shift valves for switching the supply of pressure fluid to the hydraulic actuators, and a plurality of shift valves for each shift valve for controlling actuation of these shift valves. comprising electromagnetic means;
Each of the shift valves is actuated based on a combination of activation and deactivation of each electromagnetic means to create a desired one of a plurality of speeds, and the fluid for the friction element A neutral control valve is provided to control the actuator to create a neutral state, and when the gear position is in a state other than the first speed, the neutral control valve is configured to control the first speed among the plurality of electromagnetic means for the shift valves. and a first electromagnetic means for a shift valve for controlling a shift between the second gear and the second gear.
The invention is characterized in that, when in the high speed state, it is controlled by an electromagnetic means other than the first electromagnetic means, and is switched to an operating position that creates the neutral state. Note that when using electromagnetic means for a shift valve, the electromagnetic means is designed to achieve a predetermined gear in either the ON or OFF state, so neutral control can be performed using only one electromagnetic means. When configured to control a valve,
It is not possible to achieve both a gear position and a neutral state. Therefore, the neutral control valve is
In order to achieve both of these requirements, it is necessary to restrict movement except when the electromagnetic means is used to bring the gear into a neutral state, so that it does not go into neutral even when the electromagnetic means is turned on and off to change gears. Since this kind of restriction of the neutral control valve needs to be performed at gears other than the first gear where neutral state control is performed, in the present invention, it is necessary to restrict the neutral control valve in the first gear and other gears. Focusing on the fact that this can be easily achieved by using an electromagnetic means for controlling the shift between the first speed and the second speed, which have different operating states, the electromagnetic means between the first speed and the second speed can be controlled by a neutral control valve. By using it for restraint and operating the neutral control valve using other electromagnetic means, it is possible to achieve a neutral state with a simple configuration. (Effects of the invention) In the electronically controlled automatic transmission of the invention, the neutral control valve that creates a neutral state is operated by controlling it in combination with an electromagnetic means for speed change control.
No dedicated electromagnetic means is required, and the overall device structure is simple and light in weight. (Embodiment) An electronically controlled automatic transmission according to a preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a cross section of an automatic transmission portion of an electronically controlled automatic transmission according to an embodiment of the present invention and a hydraulic control circuit. Structure of Automatic Transmission The automatic transmission includes a torque converter 10, a multi-stage gear transmission mechanism 20, and an overdrive planetary gear transmission mechanism 50 disposed between the torque converter 10 and the multi-stage gear transmission mechanism 20. has been done. The torque converter 10 includes a pump 11 coupled to an engine output shaft 1, a turbine 12 disposed opposite the pump 11, and a stator 13 disposed between the pump 11 and the turbine 12. A converter output shaft 14 is coupled to the converter output shaft 14 . Converter output shaft 14 and pump 1
A lock-up clutch 15 is provided between the lock-up clutch 1 and the lock-up clutch 15. This lockup clutch 15 is
The clutch 1 is constantly pushed in the engagement direction by hydraulic oil pressure circulating within the torque converter 10.
5 is maintained in the released state by release hydraulic pressure supplied from the outside. The multi-stage gear transmission mechanism 20 includes a front planetary gear mechanism 2
2 and a rear planetary gear mechanism 22, and a sun gear 23 of the front planetary gear mechanism 21 and a rear planetary gear mechanism 22.
It is connected to the sun gear 24 by a connecting shaft 25. The input shaft 26 of the multi-stage gear transmission mechanism 20 is connected to the connecting shaft 25 via a front clutch 27 and to the internal gear 29 of the front planetary gear mechanism 21 via a rear clutch 28, respectively. The connecting shaft 25, that is, the sun gear 23,
24 and the transmission case is the front brake 30.
is provided. The planetary carrier 31 of the front planetary gear mechanism 21 and the internal gear 33 of the rear planetary gear mechanism 22 are connected to an output shaft 34, and a rear brake 36 is connected between the planetary carrier 35 of the rear planetary gear mechanism 22 and the transmission case.
A one-way clutch 37 is provided. This one-way clutch 37 is connected to the rear brake 36
The unidirectionality is released by the operation of . The overdrive planetary gear transmission mechanism 50 is
A planetary carrier 52 that rotatably supports a planetary gear 51 is connected to the output shaft 13 of the torque converter 10, and a sun gear 53 is connected to the direct coupling clutch 5.
4, and is coupled to an internal gear 55 via a gear 55. An overdrive brake 56 is provided between the sun gear 53 and the transmission case, and the internal gear 55 is connected to the input shaft 26 of the multi-gear transmission mechanism 20. The multi-gear transmission mechanism 20 is of a conventionally known type and has three forward speeds and one reverse speed.
28 and brakes 30 and 36 as appropriate, a desired gear stage can be obtained. The overdrive planetary gear transmission mechanism 50 operates when the direct coupling clutch 54 is engaged and the brake 56 is released, and when the shafts 14 and 26 are directly coupled, the brake 56 is engaged and the clutch 54 is released. Shafts 14 and 26 are coupled in overdrive. Hydraulic Control Circuit The automatic transmission described above includes a hydraulic control circuit as shown in FIG. This hydraulic control circuit includes an oil pump 100 driven by an engine output shaft 1.
The pressure of the hydraulic oil discharged into the pressure line 101 is regulated by the pressure regulating valve 102 and the pressure is adjusted by the select valve 1.
Guided to 03. The select valve 103 has 1, 2,
It has shift positions D, N, R, and P, and when the select valve is in the 1, 2, and D positions, the pressure line 101 communicates with port a of the valve 103. Port a is connected to the actuator 10 for actuating the rear clutch 28 via the neutral control valve NC.
4 and the rear clutch 28 is held engaged when the valve 103 is in the position described above. Port a is also connected near the left end of the 1-2 shift valve 110, pushing its spool to the right in the figure. Port a is further
The right end of the 1-2 shift valve 110 is connected to the 2-3 shift valve 1 through the second line L2.
3-4 through the third line L3 to the right end of 20
They are respectively connected to the upper ends of the shift valves 130. Above 1st, 2nd and 3rd lines L1, L
First, second and third drain lines D1, D2 and D3 are branched from 2 and L3, respectively, and these drain lines D1, D2, D3
There are first, second and third solenoid valves SL1, SL1, which open and close the drain lines D1, D2, D3.
SL2 and SL3 are connected. The above-mentioned solenoid valves SL1, SL2, SL3 are normally closed valves, and when the line 101 and port a are in communication and are in a non-energized state, each drain line D1, D2, D3
, thereby increasing the pressure in the first, second, and third lines. Port a is further connected to the front brake 3 via a 1-2 shift valve 110, i.e. via a line 141 when the spool of said valve 110 moves to the left.
In this way, when the port a is communicated with the engagement side pressure chamber of the actuator 108, hydraulic pressure is introduced into the engagement side pressure chamber. The front brake 30 is held in the operating direction. On the other hand, a line 142 is connected to the withdrawal side pressure chamber of the actuator 108, and this line 142 is connected to the 1-2 shift valve 110 and the 2-2 shift valve 110.
When the spools of the 3-shift valve 120 both move to the left in the figure, they are communicated with port a via a line 141. When the line 142 is connected to the port a in this way, the same hydraulic pressure is introduced from the port a into both the engagement side pressure chamber and the disengagement side pressure chamber of the actuator 108.
Due to the difference in pressure receiving area, the front brake 30 is now operated in the releasing direction. Also,
Pressure in line 142 is also directed to actuator 109 of forward clutch 27, which
7. The select valve 103 has a port b leading to the pressure line 101 in one position;
passes through line 112 to the 1-2 shift valve 110, and further passes through line 113 to the rear brake 36.
is connected to the actuator 114 of. When the solenoid valves SL1 and SL2 are de-energized by a predetermined signal, the 1-2 shift valve 110 and the 2-3 shift valve 120 move the spool to switch the line, thereby switching a predetermined brake or clutch. is activated, and the 1-2 and 2-3 speed change operations are performed, respectively. In addition, the hydraulic pressure control circuit includes a cutback valve 115 that stabilizes the hydraulic pressure from the pressure regulating valve 102, and a pressure regulating valve 115 that stabilizes the hydraulic pressure from the pressure regulating valve 102.
A vacuum throttle valve 116 for changing the line pressure from the engine, and a throttle backup valve 117 for assisting the throttle valve 116 are provided. Further, the hydraulic control circuit of this example includes a 3-4 shift valve 1 for controlling a clutch 54 and a brake 56 of an overdrive planetary gear transmission 50.
30 and an actuator 132 are provided. The engagement side pressure chamber of the actuator 132 is connected to the pressure line 101.
The brake 56 is pushed in the engaging direction by the pressure. This 3-4 shift valve is also 1-2, 2-3 above.
Like the shift valves 110 and 120, it is a normally closed valve,
When solenoid valve SL3 is de-energized, spool 131 of valve 130 moves downward, pressure line 101 and line 122 are cut off, and line 1
22 is drained. This results in brake 5
The hydraulic pressure acting on the release side pressure chamber of actuator 132 of No. 6 disappears, and the brake 56 is actuated in the engaging direction, and the actuator 132 of clutch 54 acts to release clutch 54. Further, the hydraulic control circuit of this example is provided with a lock-up control valve 133, which is connected to the select valve 1 via a line L4.
It is connected to port a of 03. This line L
A drain line D4 is branched from the drain line D4 and is provided with a solenoid valve SL4, similar to the drain lines D1, D2, and D3. Lockup control valve 13
3, the solenoid valve SL4, which is a normally open valve, is energized, the drain line D4 is closed, and the line L4 is closed.
When the pressure inside increases, the spool cuts off line 123 and line 124, and also cuts off line 1.
24 is drained to move the lock-up clutch 15 in the connection direction. As can be seen from the above description, when the first, second, and third solenoid valves SL1, SL2, and SL3 are all in the ON state, the lines L1, L2, and L3 are all drained, and therefore the rear clutch 28, The clutch 54 and the one-way clutch 37 are in the connected state, and the gear stage is in the first speed state. When a neutral state is required in this first speed state, the second solenoid SL2 is turned OFF.
condition, thus closing drain line D2, resulting in an increase in pressure in line L2. This pressure is applied to the above neutral control valve NC
, and move the spool to the left in the diagram. When the spool of the neutral control valve NC moves to the left in this way, the actuator 104 for actuating the rear clutch 28 moves as follows.
The connection with port a is cut off and no hydraulic pressure is supplied, thereby releasing the rear clutch 28 and creating a neutral state of the transmission. In the above configuration, the operational relationship between each gear, the lockup and each solenoid, and each gear

【table】

【table】

[Table] In addition, the first, second, third and fourth solenoid valves SL1, SL2, SL3 and SL as described above
The operation control in step 4 may be performed by, for example, an electronic device that automatically performs speed change control based on a speed change map. Such an electronic device is conventionally known, and since this electronic device itself is not unique in the present invention, a description thereof will be omitted. In the above-described embodiments, the second solenoid valve SL2 is mainly controlled to perform neutral control, but the third solenoid valve SL2 is
It is also possible to perform neutral control by mainly controlling SL3. FIG. 2 shows an example of a hydraulic circuit for performing neutral control by controlling the third solenoid valve SL3. Since the operating state is almost the same as that of the hydraulic circuit shown in FIG. 1, the explanation thereof will be omitted.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a cross section of a transmission portion and a hydraulic control circuit of an electronically controlled automatic transmission according to a first embodiment of the present invention, and FIG. 2 is a diagram showing an electronically controlled automatic transmission according to a second embodiment of the present invention. FIG. 2 is a diagram showing a cross section of a transmission portion of the automatic transmission and a hydraulic control circuit. 10... Torque converter, 20... Gear transmission mechanism, 27, 28, 54... Clutch, SL1,
SL2, SL3, SL4...Solenoid valves.

Claims (1)

[Scope of utility model registration request] A torque converter connected to the output shaft of the engine, a speed change gear mechanism connected to the output shaft of this torque converter, a plurality of friction elements that switch the power transmission path of this speed change gear mechanism, and a fluid actuator that operates these friction elements. , a plurality of shift valves for switching the supply of pressure fluid to the hydraulic actuator, and a plurality of electromagnetic means for each shift valve for controlling the actuation of these shift valves, based on the combination of activation and deactivation of each electromagnetic means. A new system configured to operate each of the shift valves to create a desired one of a plurality of speeds, and to control the fluid actuator for the friction element to create a neutral state. A neutral control valve is provided, and the neutral control valve is configured to control a shift between the first speed and the second speed among the plurality of shift valve electromagnetic means when the gear position is in a state other than the first speed. The valve is restrained in an inoperative state by a first electromagnetic means, and is controlled by an electromagnetic means other than the first electromagnetic means when the gear is in a first speed state, and is switched to an operating position producing the neutral state. Electronically controlled automatic transmission.