JPH066973B2 - Control device for automatic transmission with sub-transposition - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for performing shift control of an automatic transmission, and more specifically, a sub-transmission is connected to an output side of a main transmission for automatic transmission. The present invention relates to an automatic transmission.

(Prior Art) An automatic transmission for a vehicle includes a torque converter and a plurality of gear trains, and an engine output output via the torque converter is controlled by a predetermined gear train according to a vehicle speed and an engine load. It is often used that the wheel is selected and transmitted to the wheels so that the gear is automatically changed according to the running state. When using such an automatic transmission, it is necessary to detect the engine load and the vehicle speed for automatic shift control. Therefore, the engine load is detected by detecting the engine intake negative pressure, and the transmission output rotation is detected. It is generally performed to detect the vehicle speed by detecting.

To detect the vehicle speed by detecting the output rotation of the transmission, there is a method of detecting the vehicle speed by using a governor valve that obtains an oil pressure corresponding to the vehicle speed by the centrifugal oil pressure generated by the output rotation.
An example of performing shift control using a governor valve is an automatic transmission disclosed in, for example, Japanese Utility Model Publication No. 48-27324. In this case, the governor valve is controlled by a solenoid so that the shift timing can be variably controlled. In this way, unburned components in the exhaust gas when the engine temperature is low are reduced.

When the output shaft of the transmission is directly connected to the front wheel or rear wheel differential via the drive shaft, the rotation of the transmission output shaft is proportional to the vehicle speed. If requested, the vehicle speed can be immediately detected from the hydraulic pressure generated by the governor valve, but in some cases an auxiliary transmission may be connected to the output side of the transmission (main transmission). In this case, the output rotation of the main transmission is Even if they are the same, since the vehicle speed changes due to the shift of the auxiliary transmission, there is a problem that the output rotation of the main transmission cannot be used as it is as a vehicle speed signal.

(Object of the Invention) In view of such a problem, the present invention adjusts the hydraulic pressure generated from the governor valve in correspondence with the output shaft rotation speed of the main transmission in correspondence with the shift operation of the auxiliary transmission, and always adjusts it to the vehicle speed. It is an object of the present invention to provide a control device for a sub-transformation automatic transmission that can obtain a corresponding hydraulic pressure.

(Structure of the Invention) A control device of the present invention is a main transmission that operates a shift valve to perform automatic gear shifting based on a pressure relationship between a hydraulic pressure corresponding to an output rotation speed generated by a governor valve and a hydraulic pressure corresponding to an engine load. In the sub-variant automatic transmission including the sub-transmission that changes the output shaft rotation of the main transmission, the sub-transmission is operated at the low speed side by the hydraulic pressure adjusting means provided in the hydraulic passage acting on the shift valve. It is characterized in that the hydraulic pressure generated by the governor valve is reduced when switched to, and the hydraulic pressure corresponds to the vehicle speed.

(Examples) Hereinafter, preferred examples of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an automatic transmission 100 with a sub-transmission having a control device according to the present invention.
Is a torque converter 1, a main transmission 10 and an auxiliary transmission 2
It consists of zero. The torque converter 1 is composed of an impeller 1a, a turbine 1b and a stator 1c, an engine output shaft is connected to the impeller 1a, the engine output speed is changed according to the torque converter output load, and a main transmission input shaft 2 is provided.
Is transmitted to. The main transmission 10 includes a plurality of planetary gear trains,
The control valve 12 includes a plurality of clutches and brakes for selectively operating the plurality of planetary gear trains to change gears, and a control valve 12 for controlling the operation of the clutches and brakes. The clutch and brake are appropriately operated by the hydraulic pressure, and the power transmission path of the planetary gear train is determined by this operation. Therefore, the rotation of the main transmission input shaft 2 is speed-changed via the determined planetary gear train and transmitted to the main transmission output shaft 11 as described above.

A governor valve 5 is arranged around the main transmission output shaft 11, and the governor valve 5 is adapted to obtain a hydraulic pressure P1 corresponding to the rotational speed of the main transmission output shaft 11. This hydraulic pressure P1 is converted into a hydraulic pressure P2 corresponding to the vehicle speed by the hydraulic pressure adjusting means described later, and the hydraulic pressure P2 corresponding to the vehicle speed and the hydraulic pressure Pe corresponding to the engine load obtained by using the engine intake negative pressure are supplied to the control valve 12. Acting, and in the control valve 12,
Based on the pressure relationship between the two hydraulic pressures P2 and Pe, the operating hydraulic pressure is selectively supplied to and discharged from each clutch and brake to perform automatic gear shifting.

Main transmission output shaft 1 automatically shifted by main transmission 10
The rotation of No. 1 is directly transmitted to the auxiliary transmission input shaft 21 via the sleeve 13. The sub transmission 20 has the input shaft 21 and the output shaft 26 arranged on the same shaft, and the second gear 28 a that meshes with the first gear 27 integrally formed on the input shaft 21.
And the fourth gear 3 rotatably mounted on the output shaft 26.
An idler gear 28 integrally having a third gear 28b meshing with 0 is rotatably arranged on an idler shaft 29. Further, a first spline 21a is provided at the rear of the input shaft 21, and a second spline 26a is provided at the front end of the output shaft 26.
However, the third spline 30a is formed at the front end of the fourth gear 30, and the first and third splines 21a, 3a are formed.
0a are arranged to face each other so as to sandwich the second spline 26a. A sleeve 25 slidable in the front-rear direction (axial direction) meshes with the second spline 26a, and this sleeve 25 is engaged with a shift fork 24 slidable on the rod 23. The shift fork 24 is engageable with the lower end of the lever 22 which is rotated back and forth (in the direction of arrow A) about the spherical bush 22a as a fulcrum.
It is slid back and forth on the rod 23 according to the rotation of 2.

Therefore, when the occupant operates the lever 22 to slide the shift fork 24 forward (to the left in the drawing) and move the sleeve 25 forward, the sleeve 25 moves to the second spline 26.
It also meshes with the first spline 21a while meshing with a, so that the input shaft 21 and the output shaft 26 are directly connected via the sleeve 25. On the other hand, when the shift fork 24 is slid rearward (to the right) and the sleeve 25 is moved rearward, the sleeve 25 and the first spline 21a are disengaged, and instead the third spline 30a is meshed. To do. Therefore, the sleeve 25 allows the output shaft 26 and the fourth gear 30 to move.
Are integrally connected, and the rotation of the input shaft 21 is transmitted to the output shaft 26 via the first to fourth gears 27, 28a, 28b and 30, and the speed is changed according to the gear ratio determined by the number of teeth of these gears. To be done. In this way, in the auxiliary transmission 20, the gear shift is performed in two stages according to the operation of the lever 22.

The rotation of the output shaft 26 is transmitted from the coupling 26a to the rear wheels via a drive shaft or the like. The transmission of this embodiment is a four-wheel drive transmission. Therefore, on the output shaft 26, a hub 32 having a sleeve 33 that is slidable back and forth on the outer periphery is fixedly installed.
The upper part of the sleeve 33 is connected to a slidable shift fork 34, and the sleeve 33 is slid forward and backward by the forward and backward movement of the shift fork 34 by the lever 22. A drive gear 31 rotatable on the output shaft 26 is disposed on the front side of the hub 33, and when the sleeve 33 is moved forward, the sleeve 33 and a fourth spline 31a formed at the rear end of the drive gear 31 are provided. It is supposed to mesh.
By this meshing, the output shaft 26 and the drive gear 31 are integrally connected, and both rotate in the same direction. The drive gear 31 is connected to a driven gear 37 via a chain 36, and the rotation of the output shaft 26 is thereby driven.
Is transmitted to the front wheels via the coupling 38. That is, it is possible to select either the drive for only the rear wheels or the drive for four wheels by moving the sleeve 33 back and forth.

Next, the hydraulic pressure adjusting means used for converting the hydraulic pressure P1 according to the rotation speed of the main transmission output shaft 11 into the hydraulic pressure P2 according to the vehicle speed by the governor valve 5 in the above transmission will be described with reference to FIG.

The hydraulic pressure adjusting means 40 includes a switching valve 50 and a high pressure valve 5.
5, having a low pressure valve 56 and a shuttle valve 57,
These valves are connected to the first to fourth passages 41 to 44 as shown.
It will be communicated with. The hydraulic pressure P1 corresponding to the rotation speed of the main transmission output shaft 11 generated from the governor valve 5 is applied to the first passage 4
1 is supplied to the switching valve 50 from the first passage 41. The switching valve 50 includes a spool 51 that is slidable left and right in the figure, a spring 52 that biases the spool 51 to the left in the figure, and a solenoid 53 that pushes the spool 51 to the right against the biasing force of the spring 52. To have. When the solenoid 53 is OFF, the spool 5
1 is pushed to the left by the biasing force of the spring 52, and the first passage 41 is pushed through the groove 51a of the spool 51 as shown in the figure.
And the second passage 42 communicate with each other, while the solenoid 53 is turned on.
When it is N, the solenoid spool 53a pushes the spool 51a to the right, so that the groove 51a of the spool 51 connects the first passage 41 and the third passage 43. The solenoid 53 is turned on / off in accordance with the shift operation of the auxiliary transmission. When the auxiliary transmission is in the high speed stage, the solenoid 53 is off, and when the auxiliary transmission is in the low speed stage, the solenoid 53 is on. It is like this.

A high pressure valve 55 communicates with the second passage 42, the sub transmission is in a high speed stage, and when the hydraulic pressure P1 from the governor valve 5 is supplied to the second passage 42 via the switching valve 50,
This hydraulic pressure is regulated by the high pressure valve 55 and converted into the hydraulic pressure P2 corresponding to the vehicle speed, and then supplied to the fourth passage 44 through the shuttle valve 57. From this state, when the auxiliary transmission shifts and shifts to the low speed stage, the rotation of the main transmission output shaft 11 for the same vehicle speed becomes higher and the hydraulic pressure P1 from the governor valve 5 also becomes higher than in the high speed stage. However, at this time, the solenoid 53 is turned on at the same time as the shift of the auxiliary transmission, and the first passage 41 and the third passage 43 communicate with each other, so that the hydraulic pressure P1 supplied to the first passage 41 flows to the third passage 43. It is supplied, where the pressure is adjusted by the low pressure valve 56. The low-pressure valve 56 is a valve that lowers the hydraulic pressure P1 according to the gear ratio of the auxiliary transmission and converts the hydraulic pressure P1 into the hydraulic pressure P2 corresponding to the vehicle speed. It is supplied to the fourth passage 44 via the valve 57.

As described above, the hydraulic pressure P1 from the governor valve 5 supplied to the first passage 41 is always converted into the hydraulic pressure P2 corresponding to the vehicle speed by the hydraulic pressure adjusting means 40 regardless of the shift of the auxiliary transmission 20, and then the fourth passage. The hydraulic pressure P2 from the fourth passage 44 is sent to the control valve 12.
Therefore, regardless of the shift of the auxiliary transmission, the automatic shift corresponding to the vehicle speed can always be performed.

(Effect of the Invention) As described above, according to the present invention, the hydraulic pressure P1 obtained from the governor valve in accordance with the rotation of the output shaft of the main transmission is
Adjust the pressure according to the shift of the auxiliary transmission using the hydraulic pressure adjusting means,
Since the hydraulic pressure P2 is adapted to correspond to the vehicle speed, automatic gear shifting can always be performed based on the hydraulic pressure P2 corresponding to the vehicle speed, regardless of the shift of the auxiliary transmission. Not hurt,

[Brief description of drawings]

FIG. 1 is a sectional view showing an automatic transmission having a control device of the present invention, and FIG. 2 is a hydraulic circuit showing hydraulic pressure adjusting means used in the control device of the present invention. DESCRIPTION OF SYMBOLS 1 ... Torque converter, 5 ... Governor valve 10 ... Main transmission, 12 ... Control valve 20 ... Auxiliary transmission, 22 ... Lever 24 ... Shift fork, 36 ... Chain 50 ... Changeover valve, 55 ... High pressure valve 56 ... Low pressure valve, 57 … Shuttle valve

Claims (1)

[Claims] 1. A governor valve for generating a hydraulic pressure corresponding to an output shaft rotation speed is provided inside, and a shift valve is activated by operating a shift valve according to a pressure relationship between a hydraulic pressure corresponding to an engine load and a hydraulic pressure corresponding to the output shaft rotation speed. In a sub-transition automatic transmission including a main transmission that shifts gears and an auxiliary transmission that is connected to an output section of the main transmission and that shifts the output rotation of the main transmission, a hydraulic pressure that acts on the shift valve. In the middle of the passage, there is provided hydraulic pressure adjusting means for reducing the hydraulic pressure corresponding to the output rotation speed in response to the switching of the auxiliary transmission to the low speed side and converting the hydraulic pressure into the hydraulic pressure corresponding to the vehicle speed. Control device for automatic transmission with secondary transformation.