JP2646918B2 - Transmission control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a transmission.

[0002]

2. Description of the Related Art As a conventional control device for a transmission, as disclosed in Japanese Patent Application Laid-Open No. 57-124036, there is a device for reducing the hydraulic pressure applied to a clutch when a racing select is performed. . The racing select means performing a select operation from a neutral range (P and N ranges) to a travel range (D and R ranges, etc.) while the engine is running at a high speed. When such a racing selection is performed, torque is suddenly input to the transmission, and the V-belt is broken. To prevent this, at the time of racing selection,
The hydraulic pressure applied to the forward clutch or the reverse clutch is reduced, and these are slid to generate heat, thereby preventing a sudden change in torque.

[0003]

However, in the conventional transmission control device as described above, since the racing select is determined based on the engine speed, if the engine speed sensor fails, actually, the engine speed sensor is broken. Even if the racing selection is performed, it is not determined to be the racing selection, and there is a possibility that a failure such as breakage of the V-belt occurs. An object of the present invention is to solve such a problem.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem by determining that the signal is a racing select when a signal from an engine speed sensor is not input. That is, the present invention includes an engine rotational speed sensor for detecting the engine rotational speed, a shift position switch for detecting the position of Serekureba, switching Serekureba the engine speed to the traveling range from a neutral range in the form of more than a predetermined value FIG. 1 shows a transmission control device having racing selection protection means for lowering the hydraulic pressure applied to the traveling frictional engagement element to a value lower than the operating hydraulic pressure at the time of normal switching . As shown, when the signal from the engine rotation speed sensor is smaller than a predetermined value that is smaller than the idling rotation speed, a sensor failure protection means for activating the racing selection protection means is provided. .

[0005]

When the selection from the neutral range to the driving range is made in a state where the engine rotational speed sensor has failed and no signal is output from this time, it is always determined to be a racing select and the control for reducing the hydraulic pressure of the driving friction engagement element is performed. Is performed. This prevents a sudden change in torque from being input when a racing select is performed.

[0006]

FIG. 2 shows a power transmission mechanism of a continuously variable transmission. The continuously variable transmission includes a fluid coupling 12, a forward / reverse switching mechanism 15, a V-belt type continuously variable transmission mechanism 29, a differential gear 56.
And the like, so that the rotation of the output shaft 10a of the engine 10 can be transmitted to the output shafts 66 and 68 at a predetermined gear ratio and rotation direction. The continuously variable transmission includes a fluid coupling 12 (having a lock-up oil chamber 12a, a pump impeller 12b, a turbine runner 12c, a lock-up clutch 12d, etc.), a rotating shaft 13, a drive shaft 14, and a forward / reverse switching mechanism. 15, drive pulley 16 (fixed cone member 1)
8, drive pulley cylinder chamber 20 (chamber 20a, chamber 20
b), comprising a movable cone member 22, a groove 22a, etc.),
Planetary gear mechanism 17 (sun gear 19, pinion gear 21,
A pinion gear 23, a pinion carrier 25, an internal gear 27, etc.), a V-belt 24, a driven pulley 2
6 (fixed cone member 30, driven pulley cylinder chamber 32,
Driven cone 28, forward clutch 40, drive gear 46, idler gear 48, reverse brake 50, idler shaft 52, pinion gear 54,
Final gear 44, pinion gear 58, pinion gear 60, side gear 62, side gear 64, output shaft 66,
Although it is composed of the output shaft 68 and the like, a detailed description thereof will be omitted. The configuration of the parts not described is described in Japanese Patent Application Laid-Open No.
No. 5353.

FIGS. 3, 4, 5 and 6 show a hydraulic control device for a continuously variable transmission. This hydraulic control device includes an oil pump 10
1. Line pressure regulating valve 102, manual valve 104, shift control valve 106, regulating pressure switching valve 108, step motor 11
0, transmission operation mechanism 112, throttle valve 114, constant pressure regulating valve 116, solenoid valve 118, coupling pressure regulating valve 1
20, a lock-up control valve 122, etc., which are connected to each other as shown in the drawing. The forward clutch 40, the reverse brake 50, the fluid coupling 12, the lock-up oil chamber 12a, the drive pulley The cylinder chamber 20 and the driven pulley cylinder chamber 32 are also connected as shown. Detailed description of these valves and the like will be omitted. The parts for which the description has been omitted are described in the above-mentioned JP-A-61-105353. 3, 4 and 5 indicate the following members. Pinion gear 110a, tank 130, strainer 131, oil passage 132, relief valve 133, valve hole 134, port 13
4a-e, spool 136, land 136a-b, oil passage 138, one-way orifice 139, oil passage 140, oil passage 1
42, one-way orifice 143, valve hole 146, port 1
46a-g, spool 148, lands 148a-e, sleeve 150, spring 152, spring 154,
Transmission ratio transmission member 158, oil passage 164, oil passage 165, orifice 166, orifice 170, valve hole 172, ports 172a-e, spool 174, lands 174a-c,
Spring 175, oil passage 176, orifice 177, link 178, oil passage 179, pin 181, rod 182,
Lands 182a-b, rack 182c, pin 183, pin 185, valve hole 186, ports 186a-d, oil passage 18
8, oil passage 189, oil passage 190, valve hole 192, port 19
2a-g, spool 194, lands 194a-e, negative pressure diaphragm 198, orifice 199, orifice 2
02, orifice 203, valve hole 204, port 204a
-E, spool 206, lands 206a-b, spring 208, oil passage 209, filter 211, orifice 216, port 222, solenoid 224, plunger 224a, spring 225, valve hole 230, port 23
0a-e, spool 232, land 232a-b, spring 234, oil passage 235, orifice 236, valve hole 2
40, ports 240a-h, spool 242, land 2
42a-e, oil passage 243, oil passage 245, orifice 24
6, orifice 247, orifice 248, orifice 249, choke-type throttle valve 250, relief valve 25
1. Choke type throttle valve 252, pressure holding valve 253, oil passage 25
4, cooler 256, cooler pressure holding valve 258, orifice 2
59, changeover detection switch 298.

FIGS. 7, 8 and 9 show an electronic control unit 30 for controlling the operation of the step motor 110 and the solenoid 224.
Indicates 0. The electronic control unit 300 includes an input interface 311, a reference pulse generator 312, a CPU (central processing unit) 313, a ROM (read only memory) 314,
It has a RAM (random access memory) 315 and an output interface 316, which are connected by an address bus 319 and a data bus 320. The electronic control unit 300 includes an engine rotation speed sensor 301, a vehicle speed sensor 302, a throttle opening sensor 303, a shift position switch 304, a turbine rotation speed sensor 305, an engine coolant temperature sensor 306, a brake sensor 307, and a switching detection switch 298. Is directly or by the waveform shapers 308, 30
9 and 322 and input through the A / D converter 310, while signals are output to the stepper motor 110 through the amplifier 317 and lines 317a-d, and the solenoid 2
Signals are also output to 24, but a detailed description thereof will be omitted. The configuration of a portion whose description is omitted is described in the above-mentioned Japanese Patent Application Laid-Open No. 61-105353.

FIG. 10 shows the control at the time of the select operation.
Is performed according to the control flow shown in FIG. First, it is determined whether the engine speed is higher than A (step 102). As the value of A, an engine rotation speed that is determined to be a racing select is set.
If the engine speed is higher than A, it is determined whether or not a selection operation from the neutral range to the driving range has been performed (No. 104), and if the selection operation has been performed, the clutch at the time of racing selection is determined. Pressure control is performed (the same 106). That is, control is performed to lower the operating pressures of the forward clutch 40 and the reverse brake 50, which are running friction elements, for a predetermined time from the selection. On the other hand, when the selection operation is not switching to the travel range, normal clutch pressure control is performed (the same 108). If the engine speed is smaller than A in step 102,
It is determined whether the engine speed is lower than B (110). As the value of B, an engine speed that is sufficiently lower than the idling speed is set. If the engine rotation speed is lower than B, that is, if no signal is substantially input from the engine rotation speed sensor 301, it is determined whether or not a selection operation has been performed (112), and the selection operation is performed. If so, clutch pressure control at the time of racing select is performed (106). On the other hand, when the engine rotation speed is higher than B, normal clutch pressure control is performed (the same as in the first embodiment).
08). As a result, if the engine speed sensor fails due to the above control and no signal is output from now on, the control for lowering the clutch pressure is performed at the same time as selecting the driving range, and excessive torque fluctuation is applied to the V belt. Input is prevented. This prevents an accident such as breakage of the V-belt from occurring even if the engine speed sensor is out of order.

[0010]

As described above, according to the present invention, when the engine rotational speed sensor fails, the hydraulic pressure of the running frictional engagement element is reduced as in the case of racing selection. Even if the engine speed sensor fails, it is possible to prevent occurrence of a failure due to racing selection.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between components of the present invention.

FIG. 2 is a skeleton diagram of a continuously variable transmission.

FIG. 3 is a diagram showing a left part of a hydraulic control device of the continuously variable transmission.

FIG. 4 is a diagram showing a central portion of a hydraulic control device of the continuously variable transmission.

FIG. 5 is a diagram showing a right part of a hydraulic control device of the continuously variable transmission.

FIG. 6 is a diagram showing an arrangement relationship of FIGS. 3, 4, and 5;

FIG. 7 is a diagram illustrating a left portion of the electronic control device.

FIG. 8 is a diagram showing a right portion of the electronic control device.

FIG. 9 is a diagram showing an arrangement relationship between FIGS. 7 and 8;

FIG. 10 is a diagram showing a control flow.

[Explanation of symbols]

 Reference Signs List 40 forward clutch (travel friction engagement element) 50 reverse brake (travel friction engagement element) 301 engine speed sensor 304 shift position switch

Claims (1)

(57) [Claims] An engine rotation speed sensor for detecting an engine rotation speed, a shift position switch for detecting a position of a select lever, and switching of a select lever from a neutral range to a travel range when the engine speed is at or above a predetermined value. And a racing select protection means for lowering the hydraulic pressure applied to the traveling frictional engagement element when applied to the vehicle. A control device for a transmission, comprising a sensor failure protection means for activating the racing selection protection means when the rotation speed is smaller than a predetermined value smaller than the rotation speed.