JPH0524379B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a control device for an automatic transmission that alleviates the shock that occurs when the engagement state of an auxiliary transmission provided in the automatic transmission is switched from idling to running. Regarding.

[Technical Background of the Invention] Automatic transmissions use fluid-based torque converters to increase the torque transmitted from the engine's rotational force. It is necessary to do so. Therefore, an auxiliary transmission using a planetary gear is installed to increase torque. The engagement state of this auxiliary transmission is switched and controlled depending on driving conditions such as the traveling speed of the vehicle and the negative pressure in the intake pipe, and appropriate rotational force is transmitted to the wheels.

[Problems with Background Art] However, since the rotational force is transmitted through the auxiliary transmission, the rotational force suddenly acts on the wheels when the auxiliary transmission is switched, causing a shock in the vehicle body.
That is, the switching operation of the auxiliary transmission is performed by control elements such as a multi-disc clutch or a brake band operated by hydraulic pressure. When the engine is rotating and the selector lever is in the parking position or neutral position, each gear of the auxiliary transmission idles and stops transmitting rotational force to the output shaft. When the selector lever is switched to the running position, the control element described above is actuated by hydraulic pressure to switch the engagement state of each gear of the auxiliary transmission from idling to running, thereby bringing the gear into the first gear engagement state. At this time, each gear that was idling enters the first gear low rotation high torque engagement state and transmits rotational force to the output shaft.
This causes shock on the vehicle body and impairs the riding feeling. Particularly in the case of an automatic transmission in which the control element for switching to the first speed is a brake band, the shock is large because the brake band is a mechanism that tends to engage suddenly. If this sudden engagement of the brake band is adjusted and relaxed using hydraulic pressure or the like, the durability of the brake band during normal operation will be impaired, and the valve mechanism for adjusting the hydraulic pressure will become complicated. Furthermore, if the engine is switched to the first speed while the engine is rotating at high speed, a large shock will occur due to sudden engagement of the brake band, and the brake band will be damaged, resulting in durability problems.

[Specific Object of the Invention] Therefore, the object of the present invention is to provide an automatic transmission with a simple structure that can alleviate the shock that occurs when the auxiliary transmission of an automatic transmission is switched from idling to running and improve the riding feeling. The objective is to realize a control device for a transmission.

[Structure of the Invention] In order to achieve this object, the present invention provides an automatic transmission in which the engagement state of an auxiliary transmission provided in the automatic transmission is switched and controlled depending on the driving state. a detection means for detecting that the position or neutral position has been switched to a running position and outputting a signal; and a signal output from the detection means to switch the engagement state of the auxiliary transmission from idling to a high-speed engagement state. By providing a control means for switching the auxiliary transmission to the first gear engagement state after a predetermined time has elapsed, the engagement state of the auxiliary transmission can be changed from idling to a low-torque, high-speed engagement state to first engage the auxiliary transmission and start the shock. It's easing.

[Embodiments of the Invention] Next, embodiments of the invention will be described in detail based on the drawings. FIG. 1 is a diagram showing the configuration of a hydraulic circuit and an electric circuit of an automatic transmission equipped with a control device according to the present invention. The engagement state of the auxiliary transmission 2 provided in the automatic transmission is determined by the brake band 4 and clutch 6.
It is switched by the operation of control elements such as. The operation of the brake cylinder 8 and clutch cylinder 10, which actuate the brake band 4 and clutch 6, is controlled by pressure oil supplied and distributed from a valve assembly 12. Valve assembly 12 includes a regulator valve 14, a manual valve 16, and a shift valve 18. oil pump 20
The pressure oil generated is regulated by a regulator valve 14 and distributed to each of the cylinders 8 and 10 from a shift valve 18 via a manual valve 16.

The manual valve 16 is connected to a selector lever 22 by a selector cable 24, and is interlocked with the selector lever 22. When the selector lever 22 is swung in the directions of arrows a and b to select the following positions: Park: P, Reverse: R, Neutral: N, Travel: D, and 1st gear: 1, the manual valve 16 will correspondingly shift the auxiliary gear. The hydraulic pressure feeding direction is switched to switch the machine 2 to each engagement state.

The shift valve 18 further switches the hydraulic pressure switched by the manual valve 16 according to the operating state, and controls the operation of the brake cylinder 8 and clutch cylinder 10. By detecting driving conditions such as vehicle speed and accelerator opening, a signal is output from the control mechanism 26 to the solenoid valve 28, and the shift valve 18 is switched.

As shown in FIG. 2, when the control mechanism 26 moves the selector lever 22 to the drive:D position and turns on the drive position switch 30, the control mechanism 26 determines the driving state based on signals from the vehicle speed sensor 32, accelerator switch 34, and vacuum switch 36. and outputs a switching signal. In response to this switching signal, the solenoid 38 of the solenoid valve 28 supplies and cuts off power to the battery 40, switches the shift valve 18, and shifts the auxiliary transmission 2 between the first gear engagement state and the second gear engagement state. Switch.

In this invention, a switch 4 serving as a detection means is used.
2 is provided at the travel:D position of the selector lever 22. This switch 42 is connected to the selector lever 22.
Park: P position or neutral: Drive from N position: D
When switched to the position, it turns ON and outputs a signal to the timer 44, which is a control means. This timer 44 constitutes a control unit 46 together with the control mechanism 26 as shown in FIG. The signal input to the timer 44 activates the timer 44 to output the signal. The signal output by the timer 44 is output from the solenoid 3.
8 is activated, and the auxiliary transmission 2 is switched from idling to the first gear engagement state based on signals from the travel position switch 30, vehicle speed sensor 32, etc., after once passing through the second gear engagement state. In other words, when the selector lever 22 is switched from the Park: P position or the Neutral: N position to the Travel: D position, the switch 42 is turned ON to operate the timer 44, which in turn operates the solenoid 38, and the auxiliary transmission is activated. 2 is switched from idling to a high-speed, low-torque, second-speed engagement state after a predetermined period of time, to the first-speed engagement state.

Details of the switching operation will be explained with reference to FIGS. 3 and 4. FIG. 3 shows the second speed engagement state, and FIG. 4 shows the first speed engagement state. Selector lever 2
Park 2: P position or neutral: Drive from N position:
When the switch is switched to the D position, the manual valve body 48 of the manual valve 16 moves to the position shown in FIGS. 3 and 4, and the switch 42 is turned on.

In the manual valve 16 switched by the movement of the manual valve body 48, the first chamber 50 and the second chamber 52 communicate with each other through the communication path 54. Pressure oil flowing from the oil pump 20 into the inflow port 56 via the regulator valve 14 flows out from the supply port 58. Pressure oil flowing out from the supply port 58 flows into the solenoid valve 28 via the first passage 60, the second passage 62, the third passage 64, and the valve hole 66, respectively.

Conventionally, as shown in Fig. 4, the solenoid valve 2
Since the valve body 68 of No. 8 is raised and the valve hole 66 is opened, the pressure of the pressure oil in the direction of the third passage 64 and the solenoid valve 28 does not increase, and on the other hand, the pressure oil flowing in the direction of the first passage 60 reaches the orifice 70. The pressure increases due to
The brake cylinder 8 was suddenly activated and switched to the first gear engagement state, causing a shock.

In this invention, the selector lever 22 is run:D
When switched to the position, the switch 42 starts the timer 4.
4 outputs a signal to close the solenoid valve 28. By closing the valve hole 66, the pressure oil flowing out from the supply port 58 also flows into the third passage 64. From the third passage 64 to the first groove 72
The pressure oil that has flowed into the right end surface 7 of the first piston 74
6 to move the shift valve body 78 to the left against the spring 80. When the shift valve body 78 is moved to the left, the second groove 82 is closed as shown in FIG. 3, and the third groove 84 and the fourth groove 86 communicate with each other through a small diameter portion 88. Therefore, the pressure oil flows not only in the direction of the first passage 60 but also from the second passage 62 to the third and fourth grooves 84 and 8.
It also flows in the direction of the fourth passage 90 via 6. The flow in the direction of the fourth passage 90 acts on the brake cylinder 8 in a direction to release the brake band 4, and also operates the clutch cylinder 10 to connect the clutch 6 to switch to the second speed engagement state.

When a predetermined period of time has elapsed after switching the auxiliary transmission 2 to the second speed engagement state in response to the signal from the timer 44, the timer 44 stops outputting the signal and opens the solenoid valve 28. When the valve hole 66 is opened, the pressure in the first groove 72 decreases, and the shift valve body 78
moves to the right by the elastic force of the spring 80. When the shift valve body 78 is moved to the right, the third groove 84 and the fourth groove 86 are shut off by the second piston 92, as shown in FIG. 4, and the second groove 82 and the third groove 84 are brought into communication. Through this communication, the pressure oil that was acting on the brake cylinder 8 to release the brake band 4 and the pressure oil that was acting on the clutch cylinder 10 to connect the clutch 6 are transferred to the fourth passage 90.
The oil passes through the third and second grooves 84 and 82 and is collected into an oil pan (not shown). Therefore, the pressure oil applies pressure only in the direction of the first passage 60, and the operation of the brake cylinder 8 switches the auxiliary transmission 2 from the second speed engagement state to the first speed engagement state.

In this way, the selector lever 22 of the automatic transmission
Park: P position or neutral: Drive from N position: D
position, the engagement state of the auxiliary transmission 2 is switched from idling to the high speed side 2nd gear engagement state, and after a predetermined period of time has passed, the auxiliary transmission 2 is switched to the 1st gear engagement state. Since the gear is switched to the first gear engaged state after passing through the low torque second gear engaged state, compared to the conventional device which immediately switches to the first gear engaged state,
The shock to the vehicle body can be reduced and the riding feeling can be improved.

It should be noted that switching the selector lever 22 causes the clutch cylinder 10 to operate for about 0.4 seconds, and after 0.2 to 0.3 seconds the brake cylinder 8 switches and operates, so it takes about 0.7 seconds to operate the clutch cylinder 10.
Switching is completed in about seconds. Therefore, unless the selector lever 22 is switched to another position, there will be no effect on normal operation.

[Effects of the Invention] According to the present invention, when the selector lever of the automatic transmission is switched from the parking position or the neutral position to the running position, the engagement state of the auxiliary transmission is changed from idle to high-speed engagement. By switching to the first gear engagement state after a predetermined period of time has elapsed after switching to the engagement state,
When the engagement state of the auxiliary transmission changes from idling to running, the auxiliary transmission does not directly engage from idling to the 1st gear engagement state, but first passes through the low torque, high speed engagement state and then changes to the 1st gear engagement state. Therefore, the shock can be alleviated and the riding feeling can be improved. Also, the first
Even if the control element for switching to a fast engagement state is a brake band, shock can be alleviated because sudden engagement does not occur, and when switching at high engine speeds, damage to the brake band due to sudden engagement can be avoided. can be prevented and durability can be improved. moreover,
In order to switch the engagement state of the auxiliary transmission from idling to the high speed engagement state and then to the first speed engagement state,
Since there is no need to specially provide a new control mechanism such as a valve, the structure is simple and does not become complicated, and the simplification of the structure makes maintenance easy and cost-effective.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention; Fig. 1 shows the hydraulic and electric circuit configuration of an automatic transmission; Fig. 2 shows the circuit configuration of the control unit; and Figs. 3 and 4 show the switching operation. 3 is a valve circuit diagram in the second gear engagement state, and FIG. 4 is a valve circuit diagram in the first gear engagement state. In the figure, 8 is a brake cylinder, 10 is a clutch cylinder, 16 is a manual valve, 18 is a shift valve, 22 is a selector lever, 28 is a solenoid valve, 42 is a switch, and 44 is a timer.

Claims (1)

[Claims] 1. In an automatic transmission that switches and controls the engagement state of an auxiliary transmission installed in the automatic transmission depending on the driving state, detecting that the selector lever of the automatic transmission has been switched from a parking position or a neutral position to a running position. a detection means for outputting a signal; and a signal output from the detection means to control the engagement state of the auxiliary transmission to be switched from idling to a high-speed engagement state and, when a predetermined time has elapsed, to be switched to a first speed engagement state. 1. A control device for an automatic transmission, comprising: a control means.