JPS6231762A - Controller for continuously variable transmission - Google Patents

Abstract

PURPOSE:To force an engine brake to act efficiently by changing a reduction ratio over to a larger side in an engine revolution number which is the higher, the larger a braking force is, by the use of a signal of a braking sensor. CONSTITUTION:A control sensor 16 which detects a braking operating condition is provided so as to actuate a speed change ratio control valve 8 by the use of a signal of the braking sensor 16 to change over from a high-ratio to a low ratio. And an engine revolution number at the time of the changeover from high ratio to low ratio is so controlled that it may become higher, the larger a braking force is. For this reason, the engine revolution number at the time of braking steeply becomes higher and an engine brake can be forced to function effectively.

Description

[Detailed description of the invention] The present invention relates to a control device for a continuously variable transmission.

As a transmission for ijj vehicles such as automobiles or motorcycles, a belt is hung between a driving pulley and a driven pulley, and power is transmitted by the belt, and the transmission runs along the width of the driving pulley. Continuously variable transmissions have already been developed that automatically and steplessly change the gear ratio by changing the effective diameter of the pulley according to the conditions (for example, Japanese Patent Application Laid-Open No. 70265/1983, 1■55-657
55, etc.) and are commonly used.

The present invention provides a device for detecting the deceleration state of the vehicle and controlling the gear ratio based on the deceleration signal in a vehicle equipped with a continuously variable transmission as described above, thereby facilitating smooth driving and improving safety. The purpose is to measure etc.
The embodiments shown in the accompanying drawings will be described below.

In Fig. 1.2, l is an input shaft that rotates with the rotation of the engine, and the input shaft 1 has a fixed pulley piece 2a and a slideable pulley piece 2b, and the input side V has a variable width of the pulley groove. A pulley 2 is formed, and a fluid pressure chamber 3 for controlling the sliding movement of the pulley piece 2b is provided.

4 is an output shaft, and the output shaft 4 has a fixed pulley piece 5a and a slideable pulley piece 5b, and the trM width of the pulley is set to I.
An output side V-pulley 5 with an If variable is formed, and a fluid pressure chamber 6 is provided for controlling the sliding movement of the pulley piece 5b.

”-How to write? A V-belt 7 for power transmission is hung between the V-pulley 2 and the output-side V-pulley 5101, and the V-belt 7 can transmit the rotation of the human power shaft 1 to the output shaft 4, and also transmit fluid pressure. L V pulley 2 by controlling fluid to chambers 3 and 6
By variably controlling the effective diameters of and 5, the gear ratio can be continuously controlled.

1] Control of fluid supplied to the fluid pressure chambers 3 and 6 is performed by a gear ratio control valve 8 and a fluid pressure control valve 9.

That is, the gear ratio control valve 8 is interposed in the middle of the fluid passage 14 from the fluid pump lO to the fluid pressure chamber 3 at the input end.
Fluid pressure chamber 3
The fluid pressure control valve 9 is provided on the upstream side of the gear ratio control valve 8 in the fluid passage 14, and detects the position of the input pulley piece 2b. The pump 10 is configured to control the discharge fluid pressure of the pump 10 based on the signal from the engine speed sensor 12 . Reference numeral 15 denotes a fluid passage that supplies fluid from the fluid pump 10 to the output side fluid pressure chamber 6, and the discharge fluid pressure of the pump 10 is constantly acting on the output side fluid pressure chamber 6 through the fluid passage 15. Since the fluid pressure acting area of the output side fluid pressure chamber 6 is configured to be smaller than the fluid pressure acting area of the input side, the output side pulley piece 5b operates following the operation of the input side pulley piece 2b. .

In the above, when the vehicle is stopped, the fluid pressure in the input side fluid pressure chamber 3 is small, the pulley width of the input side V pulley 2 is widened, the effective diameter of the input side V pulley 2 is small, and the effective diameter of the output side V pulley 5 is small. is in a state where the gear ratio is extremely low.

The signal from the throttle valve opening sensor 11 indicates that the larger the throttle valve opening, the greater the force that urges the gear ratio control valve 8 in the direction of closing the supply fluid passage 14 and opening the drain passage 14'. As the engine speed increases, the signal from the engine speed sensor 12 acts so that the force that biases the gear ratio control valve 8 in the opening direction increases as the engine speed increases.

Therefore, during sudden acceleration when the throttle valve is suddenly fully opened, the gear ratio control valve 8 keeps the supply fluid passage 14 closed and maintains the low ratio state shown in Figure 1 until the engine speed becomes considerably high. When the engine speed increases and the signal from the engine speed sensor 12 exceeds the signal from the throttle valve opening sensor 11, the gear ratio control valve 8 opens and the fluid discharged from the pump 10 opens. enters the input side fluid pressure chamber 3 through the supply fluid passage 14,
The pulley piece 2b is moved in the direction of the arrow in FIG. 1 to narrow the pulley width, and accordingly, the hooking position of the V-belt 7 on the input side V-pulley 2 gradually moves toward the outer circumference, and the position of the V-belt 7 on the input side V-pulley 5 is gradually moved toward the outer circumference. It moves toward the center while widening its width, and as shown in FIG. 2, the input side V-boo (gear 2) has a large effective diameter and the output side V-boo 95 has a small effective diameter, resulting in a high gear ratio. When accelerating with the throttle valve fully open, the gear ratio control characteristics are as shown in FIG. 3(a).

During slow acceleration in which the throttle valve is gradually opened, the gear ratio control valve 8 is operated at a much lower engine speed than the rapid U speed special.
is opened and the gear ratio changes from low to high, exhibiting the characteristics shown in FIG. 3(b).

In the above-mentioned continuously variable transmission, during braking deceleration while driving at a high gear ratio, the opening of the throttle valve is at its minimum, so the engine speed becomes considerably low and the signal from the engine speed sensor 12 changes to the gear ratio. After the force urging the control valve 8 in the opening direction becomes sufficiently small, the gear ratio control valve 8 operates to close the supply fluid passage 14 and open the drain passage 14', thereby switching to the low ratio side. Therefore, the engine brake does not work effectively, which is not only undesirable in terms of ensuring safe driving, but also increases the burden on the brake and causes wear and tear on the brake components. This will lead to wealth disharmony.

Therefore, in the present invention, a brake sensor 16 is provided to detect the 11j1 dynamic operation state, and based on the belief of the brake sensor 16, the gear ratio control/< lube 8 is operated to switch from a high ratio to a low ratio, and also to switch from a high ratio to a low ratio. The engine speed is variably controlled so that the higher the braking force, the higher the braking force.

In this way, when braking, the system shifts gears from a high ratio to a low ratio based on the confidence of the braking sensor, and variably controls the engine speed during the gear shifting operation so that the greater the braking force, the higher the engine speed. As a result, the engine speed during braking is significantly higher than in the past, allowing engine braking to work more effectively, making driving smoother and more stable, and significantly reducing the burden on the brakes. It is something that can be done.

Furthermore, by applying the present invention as described above to front-engine, front-drive automobiles, engine braking acts strongly on the front wheels in addition to braking by the brake system, and the braking torque of the front wheels is greater than that of the rear wheels. As a result, dangers such as rear wheel tipping and the accompanying irregular turning are completely prevented.

As the braking sensor 16, it is possible to use, for example, a switch that is activated by detecting the pedal stroke of the brake pedal, or a brake fluid pressure switch that is activated when the brake fluid pressure supplied to the wheel cylinder exceeds a predetermined value. can.

As shown in FIG. 4, the brake sensor 16 includes a master cylinder M activated by depression of the brake pedal BP.
When using a brake fluid pressure sensor PS that detects the brake fluid pressure supplied from the master cylinder MC to the wheel cylinder WC, the signal from the brake fluid pressure sensor PS is input to the control unit C and the brake fluid pressure is 15rA. (stomach)
, (U), the shift point from a high ratio to a low ratio during braking, that is, the engine braking rotational speed is variably controlled so as to increase proportionally or stepwise as the braking fluid pressure increases.

In addition, as shown in FIG. 6, a brake sensor 16 is used to detect
l (Deceleration G sensor G that detects both speeds and issues a signal
S can also be used.1. ',! ,, Deceleration G sensor GS
The control unit C determines the difference G-g between the deceleration signal G and the deceleration g that can be generated by engine braking at the engine speed at that time, and calculates this G-g.
As shown in FIG. 7 (a) or ([+) by (+ti) of g, the shift point from high ratio to low ratio during braking, that is, the engine braking rotation speed, is adjusted proportionally or It can also be configured to perform variable control in stages.

As described above, according to the present invention, in a city using a continuously variable transmission, one brake sensor is installed to detect deceleration due to braking.
．． By using the signal from the brake sensor, the reduction ratio is switched to the high engine speed when the braking force is sufficiently high, so that the engine brake is effectively applied during braking operation, resulting in smooth driving. It is possible to significantly reduce the burden on the braking device and significantly extend the life of the various components of the braking device.

When the present invention is applied to a front-wheel drive vehicle, it can completely eliminate the problem of rear wheel front-slip during braking, which is extremely effective, and has extremely great practical value.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of a control system of a continuously variable transmission according to an embodiment of the present invention. FIG. 1 shows a low ratio state, and FIG. 2 shows a high ratio state, respectively. Fig. 3 is a diagram showing the gear ratio control characteristics of a continuously variable transmission, Fig. 4 is a cross-sectional explanatory diagram showing an example of the brake sensor in Figs. 1 and 2, and Figs.
) are diagrams showing the control characteristics of the engine brake rotation speed using the brake sensor shown in FIG. 4, and FIG. 6 is a block diagram showing another example of the brake sensor, and FIG. 7 (a). (B) is a diagram showing the control characteristics of the engine braking rotation speed by the device shown in FIG. 6; ■...Input shaft, 2...Input end V pulley, 3...Input side fluid pressure chamber, 4...Output shaft, 5...Output side V pulley, 6...Output side fluid pressure Chamber, 7...V belt, 8.
...Gear ratio control/Help, 9...Fluid pressure control valve. 10... Fluid pump, 11... Throttle valve opening sensor,
12... Engine speed sensor, 14.15... Supply fluid passage, 14'... Drain passage, 16... Brake sensor. that's all

Claims (2)

[Claims] (1) An input side V-pulley whose pulley width is variably controlled by fluid pressure is provided on the input shaft, and the pulley width is variably controlled according to changes in the pulley width of the input side V-pulley on the output shaft. A V-belt is hung between both V-pulleys to transmit power, and a throttle valve opening sensor and a throttle valve opening sensor are provided in a fluid passage for controlling the pulley width of the input-side V-pulley. In a vehicle using a continuously variable transmission equipped with a gear ratio control valve operated by each signal from an engine rotation speed sensor, a brake sensor is provided that detects braking operation and issues a signal according to the braking force, and the brake sensor The gear ratio control valve is operated to increase the gear ratio in response to the signal, and the engine rotation speed when the gear ratio control valve operates to increase the gear ratio is:
A control device for a continuously variable transmission, characterized in that it is configured to variably control braking force so that it increases as the braking force increases. (2) The braking sensor is composed of a deceleration G sensor that detects vehicle deceleration during braking, and is generated by engine braking based on the braking deceleration detected by the deceleration G sensor and the engine rotation speed at that time. and the deceleration that can be achieved, and variably controls the engine rotation speed when the gear ratio control valve operates to increase the gear ratio so that the larger the difference, the higher the engine rotation speed. A control device for a continuously variable transmission according to claim 1, characterized in that: